JP2016022650A - Inkjet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording device that can adjust displacement of an ink droplet impact position between line-head type head arrays with precision finer than resolution in a sub-scanning direction.SOLUTION: A recording head control portion of a line-head type inkjet recording device outputs two head-driving waveforms Vcom for discharging ink droplets in one driving cycle, then selects the waveforms and controls discharging of the ink droplets to be discharged from each nozzle of each recording head in a head array onto a recording medium according to amounts of displacement of an ink droplet impact position between head arrays, taking into consideration the fact that preset driving cycles (discharge intervals of ink droplets) of resolution in a sub-scanning direction in a conveying direction of the recording medium can be made longer in the line head type device than in a serial head type device. This allows the displacement of the ink droplet impact position to be adjusted with precision 1200 dpi finer than the resolution 600 dpi in the sub-scanning direction.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a line head type inkjet recording apparatus having a configuration in which a plurality of recording heads are arranged so as to be equal to or larger than the width of a recording medium in the main scanning direction, and are arranged side by side in a head row in the sub scanning direction. .

  2. Description of the Related Art Conventionally, it has been known that, in an ink jet recording apparatus that is generally provided in a printer (image forming apparatus), if a line head method is employed, productivity can be significantly improved as compared with a case where a serial head method is employed.

  However, in the line head system, a plurality of recording heads are arranged side by side in the sub-operation direction that coincides with the conveyance direction of the recording medium in order to arrange a plurality of recording heads so that there is no gap between the nozzles in the main scanning direction. However, in such a configuration, there arises a problem that the ink droplet landing positions are displaced between the head rows due to the head row assembly error.

  In view of this, there has been proposed a technique for preventing the deviation of the ink droplet landing position due to such an assembly error of the head row. As such a well-known technique, for example, the mutual deviation between the recording heads can be adjusted in an easy process, which is good. And an “image recording apparatus” (see Patent Document 1) that can obtain a stable image.

  In the technique described in Patent Document 1, in order to adjust the deviation of the ink droplet landing position due to the head assembly error of the line head method of the ink jet printer, the ink droplet landing position error data when the head unit is mounted is stored, and the ink droplet landing position is stored. The head unit adjustment control unit adjusts the ejection timing of the ink droplets from the ink ejection port based on the error data. In this method, each recording head is transported by a predetermined head driving waveform. Since the drive is performed with a constant driving cycle equal to the resolution in the sub-scanning direction (sub-scanning resolution), the deviation of the ink droplet landing position between the head arrays is adjusted with a finer accuracy than the resolution in the sub-scanning direction. There is a problem that you can not.

  The present invention has been made to solve such problems, and its technical problem is to adjust the deviation of the ink droplet landing position between the head arrays of the line head system with a finer accuracy than the resolution in the sub-scanning direction. It is an object to provide a possible ink jet recording apparatus.

  In order to solve the above technical problem, the present invention has a configuration in which a plurality of recording heads are arranged so as to be equal to or larger than the width of the recording medium in the main scanning direction, and are arranged in parallel in a head row in the sub scanning direction. In the line head type ink jet recording apparatus, a plurality of recording heads arranged in parallel as a head array, a nonvolatile storage means for storing deviation information of ink droplet landing positions between the head arrays at the time of mounting, and a plurality of recording heads A plurality of head drive waveforms for ejecting ink droplets from the respective ink ejection ports are generated within a preset driving cycle of the sub-scanning resolution in the recording medium conveyance direction, and based on deviation information of ink droplet landing positions. A recording head control means for selecting the head driving waveform and driving the recording heads, and a head driving waveform selected by the recording head control means Characterized by comprising a plurality of recording head driving means for driving each of a plurality of recording heads, the based.

  According to the present invention, a plurality of head drive waveforms are generated within the drive cycle for each recording head, and the head drive waveform for ejecting ink droplets is selected based on the deviation information of the ink droplet landing positions between the head rows. Since the recording head is driven, it is possible to adjust the deviation of the ink droplet landing position between the head arrays of the line head system with a finer accuracy than the resolution of the sub-scanning.

1 is a functional block diagram showing a basic configuration of a line head type ink jet recording apparatus according to Embodiment 1 of the present invention. FIG. FIG. 2 is a functional block diagram illustrating a detailed configuration of a recording head driving unit as a main part of the ink jet recording apparatus illustrated in FIG. 1 in correspondence with various output signals from a recording head control unit. FIG. 3 is a timing chart showing the relationship between various signals for driving the recording head shown in FIG. 2. FIG. FIG. 3 is a timing chart showing the relationship between various signals for the recording head drive mask pattern shown in FIG. 2. As a comparison, FIG. 10 is a schematic diagram for explaining a deviation of ink droplet landing positions between head arrays by head driving by a recording head control unit with respect to a recording medium in a conventional ink jet recording apparatus. FIG. 6 is a schematic diagram for explaining suppression of deviation of ink droplet landing positions between head arrays by head driving by a recording head control unit with respect to a recording medium in an ink jet recording apparatus according to Embodiment 1. FIG. 7 is a schematic diagram for explaining a method for suppressing deviation of ink droplet landing positions between head rows by head driving by a recording head controller with respect to a recording medium in an ink jet recording apparatus according to Embodiment 2 of the present invention, including a head driving waveform. (A) is a diagram when the ink droplet landing deviation amount is less than 0, (b) is a diagram when the ink droplet landing displacement amount is 0, and (c) is a case where the ink droplet landing deviation amount is 0 or more. FIG. 10 is a flowchart showing setting control operation processing including delay processing by generating two head drive waveforms by the recording head control unit of the ink jet recording apparatus according to the second embodiment described in FIG. 7. FIG. 10 is a flowchart illustrating setting control operation processing including delay processing by generating two head drive waveforms and correction processing by the recording head control unit of the ink jet recording apparatus according to the third embodiment of the present invention. FIG. 6 is a functional block diagram illustrating a detailed configuration of a recording head driving unit, which is a main part of an ink jet recording apparatus according to Example 4 of the invention, including a head driving waveform in correspondence with various output signals from a recording head control unit. is there. A detailed configuration of a recording head driving unit as a main part of an ink jet recording apparatus according to a fifth embodiment of the present invention corresponds to various output signals from the recording head control unit, and the head driving waveform and a head that does not eject ink FIG. 3 is a functional block diagram including a timing chart of signals required for masking a period in which a drive waveform is input. A detailed configuration of a recording head driving unit, which is a main part of an ink jet recording apparatus according to Embodiment 6 of the present invention, corresponds to various output signals from the recording head control unit, and the head driving waveform and a head that does not eject ink 3 is a functional block diagram including a timing chart of signals required to transfer non-ejection head drive data during a period in which a drive waveform is input. FIG. FIG. 10 is a schematic diagram illustrating a print example of a test pattern on a recording medium for measuring a deviation of an ink droplet landing position by a recording head control unit of an ink jet recording apparatus according to a seventh embodiment of the invention, including a head driving waveform. . For storing in a non-volatile memory based on a test pattern generation result for measuring a deviation amount of an ink droplet landing position in a recording head controller under the control of a CPU according to a user operation instruction of an ink jet recording apparatus according to an eighth embodiment of the present invention. It is the flowchart which showed the operation | movement process to reach. It is the schematic diagram shown in order to demonstrate reading of the test pattern on the recording medium by the test pattern reading part with which the inkjet recording device which concerns on Example 9 of this invention is equipped. FIG. 15 shows an operation process leading to storage in a nonvolatile memory based on a test pattern generation result for measuring a deviation amount of an ink droplet landing position in a recording head control unit by automatic control of a CPU of the ink jet recording apparatus described in FIG. It is a flowchart.

  Hereinafter, the ink jet recording apparatus of the present invention will be described in detail with reference to the drawings, with some examples.

  FIG. 1 is a functional block diagram showing a basic configuration of a line head type inkjet recording apparatus according to Embodiment 1 of the present invention.

  Referring to FIG. 1, this ink jet recording apparatus has a host I / F (interface) 105 for connecting a host PC (personal computer) 101 that transmits image data of a print job, and hardware control of a printing function. ROM 104 storing firmware control signals to be performed and drive waveform data of eight recording heads 1 to 8 (n of recording head n is any one of 3 to 7), image data and each recording head 1 to 8 are arranged in parallel as a head row, a nonvolatile RAM 104 that stores deviation information of ink droplet landing positions between head rows at the time of mounting, a CPU 102 that controls each part, and ink from each ink ejection port of the head row Within the drive cycle of the sub-scanning resolution in the recording medium conveyance direction set in advance for the head drive waveform for discharging droplets A plurality of print heads are generated, and a head drive waveform is selected based on deviation information of ink droplet landing positions to be used for driving each of the print heads 1 to 8, and a print for conveyance obtained from the sub-scan encoder 108. A sub-scanning control unit 107 that controls the sub-scanning motor 109 at a rotation speed corresponding to the sub-scanning amount based on the position information of the medium is connected by a common bus 110. The eight recording heads 1 to 8 driving units 111 to 118 that drive the recording heads 1 to 8 to eject ink droplets based on the transferred head driving waveform data (n of the recording head n driving unit 11n is Are connected to each other to indicate any one natural number from 3 to 7.

  The RAM 104 here functions as a non-volatile storage unit that stores deviation information of ink droplet landing positions between the head rows when the recording heads 1 to 8 are arranged in parallel as head rows. Incidentally, with regard to the configuration of the line head system here, a first head in which four recording heads 1, 3, 5, and 7 are arranged in parallel in the main scanning direction at intervals less than the longitudinal dimension of each single nozzle. Similarly, the four recording heads 2, 4, 6, and 8 are arranged at intervals smaller than the longitudinal dimension of each single nozzle so as to have a predetermined head row spacing (gap) in the sub-operation direction with respect to the row. A case where the second head row is arranged in parallel in the scanning direction can be exemplified. In addition, the recording head control unit 106 sets a head driving waveform for ejecting ink droplets from the respective ink ejection ports of the recording heads 1 to 8 within a driving cycle of the sub-scanning resolution in the recording medium conveyance direction set in advance. And a recording head control means for selecting the head driving waveform based on the deviation information of the ink droplet landing positions between the head rows and for driving the recording heads 1 to 8.

  In addition, since this ink jet recording apparatus is well known and will not be described in detail, a mechanism for ejecting ink droplets to a plurality of nozzle rows arranged in a line on each recording head 1 to 8 and each recording head And a recording medium conveying means for conveying the recording medium in the sub-scanning direction perpendicular to the main scanning direction.

  In this inkjet recording apparatus, as a basic operation, the CPU 102 that has received image data of a print job from the host PC 101 via the host I / F 105 and the common bus 110 stores the image data in the RAM.

  The recording head controller is stored in the RAM 104 in response to the command from the CPU 102 in conjunction with the position information of the recording medium for conveyance obtained from the sub-scan encoder 108 via the sub-scan controller 107 and the common bus 110. The image data, head drive waveforms for the recording heads 1 to 8 stored in the ROM 103, and control signals are transferred to the recording heads 1 to 8 drive units 111 to 118.

  The recording heads 1 to 8 driving units 111 to 118 drive the recording heads 1 to 8 based on the selected data of the plurality of head driving waveforms transferred from the recording head control unit 106 to use ink droplets as recording media. By discharging, image data is printed on the recording medium.

  According to the ink jet recording apparatus according to the first embodiment, a plurality of head driving waveforms are generated within the driving cycle for each of the recording heads 1 to 8, and ink droplets are ejected based on deviation information of ink droplet landing positions between the head rows. Since the recording heads 1 to 8 are driven by selecting the head driving waveform to be used, it is possible to adjust the deviation of the ink droplet landing positions between the head arrays of the line head system with a finer accuracy than the sub-scanning resolution. .

  FIG. 2 is a functional block diagram illustrating a detailed configuration of the recording head driving unit, which is a main part of the ink jet recording apparatus according to the first embodiment described above, in relation to various output signals from the recording head control unit 106. FIG. 3 is a timing chart showing the relationship between various signals for driving the print head here, and FIG. 4 is a timing chart showing the relationship between various signals for the print head driving mask pattern here. However, FIG. 2 shows a functional block diagram when the image data has 8 gradations (3 bits), and FIG. 3 shows a timing chart when the image data has 4 gradations (2 bits).

  Referring to FIG. 2, the printhead controller 106 serially transfers [2: 0] image data SD corresponding to the number of nozzles (= actuator number) of the printhead to the printhead drive unit to transfer the image data. Input to the image data shift register 201 of the recording head drive unit at the timing of the clock SCK. At this time, if the timing of the image data transfer clock SCK indicates the rising of the rectangular wave in the time interval t1 in FIG. 3, the image data SD is input to the image data shift register 201 as [1: 0] in the time interval t1. .

  The image data shift register 201 delays the image data SD at a predetermined timing and sends it to the image data latch unit 202 of the recording head drive unit. The image data latch unit 202 receives the image data output from the recording head control unit 106. Since the latch signal SLn is input, the delayed image data SD for each nozzle held in the image data latch unit 202 is performed at the falling timing of the rectangular wave in the time interval t2 in FIG. At the rise timing, the delayed image data SD for each nozzle held by the image data latch unit 202 is sent to the gradation decoder 205 of the recording head drive unit.

  After holding the image data SD, the recording head controller 106 outputs drive waveform data for ejecting ink droplets of each gradation value from the nozzles at the timing of the time interval t3 in FIG. In terms of function, the drive waveform data is converted from a digital signal to an analog signal by a D / A converter in the drive waveform generator, and then voltage amplified by an operational amplifier (OP AMP) and then current amplified by a current amplifier. As a result, an analog signal head drive waveform Vcom is obtained, and this analog signal head drive waveform Vcom is input to the analog switch 207 of the recording head drive unit.

  At this time, the recording head driving unit has a function of making a transition so that the internally generated head driving mask pattern MN functions as a gradation control signal in the gradation decoder 205 and is selected in accordance with the timing of the head driving waveform Vcom. Give it.

  More specifically, the head drive mask pattern serial transfer data MD is serially transferred at the timing of the head drive mask pattern serial transfer clock MCK output from the print head control unit 106 and is transferred to the mask pattern shift register 203 of the print head drive unit. The head drive mask pattern serial transfer data MD is delayed at a predetermined timing by the mask pattern shift register 203 and then sent to the mask pattern latch unit 204 of the print head drive unit. The head drive mask pattern serial transfer latch signal MLn output from the head control unit 106 holds the head drive mask pattern serial transfer data MD delayed at the falling timing of the rectangular wave in FIG. Up the mask pattern latch unit 204 at the timing of holding delayed head driving mask pattern serial transfer data MD head driving mask pattern MN [7: 0] as may be the configuration to be sent to the tone decoder 205.

  The head drive mask pattern MN is also serially transferred using the head drive mask pattern serial transfer clock MCK, the head drive mask pattern serial transfer data MD, and the head drive mask pattern serial transfer latch signal MLn. Incidentally, in FIG. 3, as the head drive mask pattern MN, the head drive mask pattern MN [0] rising at the timing of half the time of the first rising peak of the head drive waveform Vcom in the time interval t3 and the falling head. Driving mask pattern MN [3], head driving mask pattern MN [2] falling at the timing of half of the second rising peak, head driving mask pattern MN falling at the timing of half of the third rising peak [1] is shown.

  In the recording head drive unit, the grayscale decoder 205 performs a logical operation on the head drive mask pattern MN and the delayed and held image data SD, and the level shifter 206 to which the logical operation result is input has a level fluctuation with respect to the head drive waveform Vcom. By opening / closing the analog switch 207 according to the control value, the actuator in the recording head is driven by the head driving waveform Vcom after different gradation decoding at each nozzle of the recording head, and as a result, based on the image data SD Ink ejection is performed on the recording medium.

  The recording head driving unit described here supports up to 8 gradations (3 bits), but by fixing the upper bit (SD [2]) of the image data SD to 0, the head driving mask pattern MN is [3]. : 0] is selected. For example, the head drive mask pattern MN [7: 4] or the like is not selected.

  FIG. 5 is a schematic diagram for explaining the displacement of the ink droplet landing positions between the head arrays A and B by the head drive in the recording head control unit with respect to the recording medium in the conventional inkjet recording apparatus as a comparison.

  Referring to FIG. 5, this ink jet recording apparatus (corresponding to Patent Document 1) uses eight recording heads 1 to 8 when arranged side by side in the main scanning direction perpendicular to the recording medium conveyance direction. With respect to the first head row A in which the recording heads 1, 3, 5, and 7 corresponding to the number are arranged in parallel in the main scanning direction at intervals less than the longitudinal dimension of each single nozzle, a gap between these nozzles is provided. In the main scanning direction, the four recording heads 2, 4, 6, and 8 are provided with a predetermined gap (interval) between the head rows in the sub operation direction so as to be filled, with an interval less than the longitudinal dimension of each single nozzle. By adopting a line head type configuration in which the second head row B arranged in parallel is arranged, productivity is improved as compared with the serial type ink jet recording apparatus.

  However, the recording heads 1, 3, 5, and 7 in the head row A and the recording heads 2, 4, 6, and 8 in the head row B are driven at a predetermined head driving waveform Vcom with a driving period of 600 dpi. If the adjustment of the ink droplet ejection timing by the recording head control unit corresponding to the head unit adjustment control unit of Patent Document 1 is applied, the head row between the first head row A and the second head row B is applied. If the gap between the heads cannot be accurately grasped, the ink droplet landing positions of the first head row A and the second head row B will be misaligned, and the sub-operation is performed after the recording medium is conveyed by the gap between the head rows. The displacement amount of the ink droplet landing position becomes 1200 dpi with respect to the resolution of 600 dpi, and a very good image cannot be obtained. As a result, the conventional ink jet recording apparatus cannot adjust the displacement of the ink droplet landing positions between the head arrays with a precision finer than the sub-scanning resolution.

  FIG. 6 is a schematic diagram for explaining a technique for suppressing the deviation of the ink droplet landing position between the head arrays A and B by the head drive by the recording head control unit 106 for the recording medium in the ink jet recording apparatus according to the first embodiment. is there.

  In general, the line head type ink jet recording apparatus has a lower conveyance speed for the recording medium than the carriage scanning speed of the serial head type ink jet recording apparatus (ink jet printer). In the apparatus, the driving cycle (ink droplet ejection interval) can be increased. Therefore, in the inkjet recording apparatus according to the first embodiment, it is noted that the drive cycle becomes long, and the recording head control unit 106 generates a plurality (two in the first embodiment) of head drive waveforms Vcom within one drive cycle. To do.

  Referring to FIG. 6, the configurations of the head arrays A and B are the same as the configuration of FIG. 5, but here the head drive waveform Vcom for the recording head control unit 106 to eject ink droplets within one drive cycle. Are selected and discharged from the nozzles of the recording heads 1 to 8 of the head arrays A and B onto the recording medium in accordance with the deviation amount of the ink droplet landing position between the head arrays A and B. This shows how the displacement of the ink droplet landing position can be adjusted with an accuracy of 1200 dpi finer than the sub-scan resolution of 600 dpi by controlling the amount of ink droplets discharged.

  In the ink jet recording apparatus according to the second embodiment of the present invention, when the recording head control unit 106 generates two head drive waveforms Vcom within the drive cycle of the sub-scanning resolution, it is set from the output of the first head drive waveform Vcom. The second and subsequent head drive waveforms Vcom are output with a certain delay time (delay of fixed value), and the delay time is adjusted by such a function, and ink droplet landing between the head arrays A and B is performed. The positional deviation can be adjusted with finer accuracy than the sub-scanning resolution.

  FIG. 7 shows a head driving waveform Vcom as a method for suppressing the deviation of the ink droplet landing position between the head arrays A and B by the head driving by the recording head control unit 106 for the recording medium in the ink jet recording apparatus according to the second embodiment of the invention. FIG. 4A is a diagram when the ink droplet landing deviation amount is less than 0, and FIG. 2B is a diagram when the ink droplet landing deviation amount is 0. FIG. FIG. 3C is a diagram when the ink droplet landing deviation amount is 0 or more.

  Specifically, the two head drive waveforms Vcom generated within one drive cycle are classified as the first half and the second half, and the ink droplet landing position deviation amount is 0 (± 0 μm) (there is no ink droplet landing position deviation). In the case), as shown in FIG. 7B, both the head row A and the head row B eject ink droplets using the head driving waveform Vcom of the first half. Further, in the case where the ink droplet landing position deviation amount is a positive value of 0 or more (+10 μm) shown in FIG. 7C and a negative value less than 0 (−10 μm) shown in FIG. The assignment of the head drive waveform Vcom of the latter half to the head row A and the head row B is changed, and the output start timing (Delay) of the latter half of the head drive waveform Vcom is set according to the ink droplet landing position deviation amount.

  FIG. 8 is a flowchart illustrating setting control operation processing including delay processing in which two head drive waveforms Vcom are generated by the recording head control unit 106 of the ink jet recording apparatus according to the second embodiment.

  Referring to FIG. 8, in the operation process of the recording head control unit 106 of the ink jet recording apparatus according to the second embodiment, an interval is set by a delay time (fixed value) set from the output of the first head driving waveform Vcom. The second and subsequent head drive waveforms Vcom are output. First, it is determined whether there is an ink droplet landing position deviation (step S1). If the result of this determination is that there is no ink droplet landing position deviation, As described with reference to FIG. 7B, the drive waveform (head drive waveform Vcom) for ejecting ink droplets is set to head row A: first half and head row B: second half (step S5). After the printing is executed (step S7), the operation process is terminated. If there is an ink droplet landing position deviation, it is subsequently determined whether the ink droplet landing position deviation amount is 0 or more (step 2).

  As a result of this determination, if the ink droplet landing position deviation amount is 0 or more (if it is positive), as described with reference to FIG. 7C, the drive waveform (head drive waveform Vcom) that ejects ink droplets is used. ) Is set to the head row A: the first half and the head row B: the second half (step S3), and if the ink droplet landing position deviation amount is not 0 or more (if it is negative), refer to FIG. As described above, the process of setting the drive waveform (head drive waveform Vcom) for ejecting ink droplets to the head row A: the second half and the head row B: the first half (step S5) is performed. After setting a delay value based on the amount of droplet landing position deviation (step S6) and executing printing (step S7), the operation process is terminated.

  In the ink jet recording apparatus according to the third embodiment of the present invention, the recording head control unit 106 uses the sub-scanning encoder 108 to the sub-scanning control unit 107 from the ink droplet landing position deviation information stored in the nonvolatile RAM 104 and the delay time setting. And based on the immediately preceding sub-scan encoder cycle information obtained via the common bus 110, and by correcting and setting the delay time based on the immediately preceding sub-scan encoder cycle information by such a function, Even when the conveyance speed of the recording medium changes due to increase / decrease or the like, it is possible to prevent the deviation of the ink droplet landing position due to the change of the conveyance speed.

  Specifically, when the two head drive waveforms Vcom generated within one drive cycle are classified as the first half and the second half and the ink droplet landing position deviation amount is 0 (when there is no ink droplet landing position deviation). In both the head row A and the head row B, ink droplets are ejected using the head driving waveform Vcom in the first half. In addition, when the ink droplet landing position deviation amount is a positive value of 0 or more and a negative value of less than 0, the assignment of the head drive waveforms Vcom of the first half and the second half to the head rows A and B is changed, and the ink The output start timing (Delay) of the latter half of the head drive waveform Vcom is set in accordance with the amount of droplet landing position deviation. Further, by correcting the delay value based on the sub-scanning encoder period immediately before ejecting ink droplets, deviation of the ink droplet landing position is prevented even when the conveyance speed of the recording medium varies due to load fluctuation or the like. Is.

  FIG. 9 is a flowchart showing setting control operation processing including delay processing and correction processing by generating two head drive waveforms Vcom by the recording head control unit 106 of the ink jet recording apparatus according to the third embodiment of the present invention. It is.

  Referring to FIG. 9, in the operation process of the recording head control unit 106 of the ink jet recording apparatus according to the third embodiment, it is set based on the immediately preceding sub-scanning encoder cycle information from the output of the first head driving waveform Vcom. The second and subsequent head drive waveforms Vcom are output at intervals of the delay time, and the first half of the determination is whether there is an ink droplet landing position deviation similar to the operation processing shown in FIG. The process from step S1) to the process of setting the delay (delay) value based on the ink droplet landing position deviation amount (step S6) is similarly performed, and the process proceeds to the printing start (step S7).

  Thereafter, the process of calculating the immediately preceding encoder cycle based on the subscanning encoder cycle information acquired from the subscanning encoder 108 (step S8) is performed, and then the delay value is corrected based on the immediately preceding encoder cycle (step S9). In step S11, it is determined whether or not the ink droplet ejection (step S10) is finished. If the result of this determination is that printing is complete, the operation process is terminated, but if printing is not terminated, the process returns to before the process for calculating the immediately preceding encoder cycle (step S8) and the subsequent processes are repeated.

  The inkjet recording apparatus according to the fourth embodiment of the present invention includes a plurality of head drive waveform generation units for the recording head control unit 106 to generate a plurality of head drive waveforms Vcom within the drive period of the sub-scanning resolution. With such a configuration, a plurality of head drive waveforms Vcom are simultaneously output, and the displacement of the ink droplet landing positions between the head arrays A and B is adjusted with a finer precision than in the case of the ink jet recording apparatus of the first embodiment shown in FIG. It is something that can be done.

  FIG. 10 is a functional block diagram illustrating a detailed configuration of a recording head driving unit, which is a main part of the ink jet recording apparatus according to the fourth embodiment of the present invention, in relation to various output signals from the recording head control unit 106.

  Referring to FIG. 10, two head drive waveform generation units are mounted here, and the head drive waveform Vcom1 is applied to the recording head drive unit that drives the head array A from the first head drive waveform generation unit. The head drive waveform Vcom2 is output from the second head drive waveform generation unit to the recording head drive unit that drives the head row B as a target.

  As in the ink jet recording apparatus according to the first embodiment described with reference to FIG. 2, if there is one head drive waveform generation unit, the head drive waveforms in the first half and the second half in FIG. Although it is not possible to set Delay such that Vcom overlaps (the more the head drive waveforms Vcom in the first half and the second half overlap, the smaller the displacement of the ink droplet landing position cannot be adjusted), the fourth embodiment shown in FIG. If two head drive waveform generation units are installed as in the configuration of, the delay can be set so that the head drive waveforms Vcom in the first half and the second half overlap. Can be adjusted.

  In the ink jet recording apparatus according to the fifth embodiment of the present invention, when the recording head control unit 106 selects two head driving waveforms Vcom within the driving cycle, the head driving is performed with respect to the recording head driving unit for each of the head arrays A and B. By transmitting the mask pattern serial transfer data, the recording head drive unit that has received the head drive mask pattern serial transfer data masks the period during which the head drive waveform Vcom that does not eject ink droplets is input. A head drive waveform Vcom for ejecting ink droplets can be accurately selected without reducing the head drive data transfer period and without increasing the head drive data transfer speed.

  FIG. 11 shows the detailed configuration of the recording head driving unit, which is a main part of the ink jet recording apparatus according to the fifth embodiment of the present invention, corresponding to various output signals from the recording head control unit 106, and the head driving waveform Vcom. 4 is a functional block diagram including a timing chart of signals required for masking a period in which a head drive waveform Vcom that does not eject ink is input.

  Referring to FIG. 11, here, when the recording head controller 106 selects the first half (head row A) and the second half (head row B) of the two head drive waveforms Vcom within the drive cycle, the head rows A and B are selected. The head drive mask pattern serial transfer data MD1 and MD2 signals are transmitted to the mask pattern shift register in each recording head drive unit, and the image data SD1 [1: 0] and SD2 [1: 0] are transferred to the image data shift register. A period during which a head driving waveform Vcom that does not eject ink droplets is input by the recording head driving unit that transmits the signal and receives these various data is masked. Further, when ejecting ink droplets, the recording head controller 106 drives the recording head driving signals MN1 [7: 0] and MN2 [7: 0] for the respective head arrays A and B. The first half and the second half of the head drive waveform Vcom can be selected by transmitting data to be masked when ink droplets are not ejected (all 1 corresponds in FIG. 11).

  In the ink jet recording apparatus according to the sixth embodiment of the present invention, when the recording head control unit 106 selects two head driving waveforms Vcom within the driving period, ink droplets are ejected from the recording head driving unit for each of the head arrays A and B. By appropriately transferring non-ejection head drive data to the recording head drive unit during the period when the head drive waveform Vcom is not input, the head drive waveform Vcom that ejects ink droplets can be selected accurately without increasing the number of signals. It is something that can be done.

  FIG. 12 shows the detailed configuration of the recording head driving unit, which is the main part of the ink jet recording apparatus according to the sixth embodiment of the present invention, in correspondence with various output signals from the recording head control unit 106, and the head driving waveform Vcom. FIG. 5 is a functional block diagram including a timing chart of signals required to transfer non-ejection head drive data during a period when a head drive waveform Vcom that does not eject ink is input.

  Referring to FIG. 12, here, when the recording head controller 106 selects the first half (head row A) and the second half (head row B) of the two head drive waveforms Vcom within the drive cycle, the head rows A and B are selected. Non-ejection head drive data in the period when the head drive waveform Vcom that does not eject ink droplets in each print head drive unit is input to the image data shift register of the print head drive unit for each of the head arrays A and B. SD1 [1: 0] and SD2 [1: 0] signals are transmitted. Further, when ejecting ink droplets, the recording head control unit 106 transmits the image data SD1 [1: 0] and SD2 [1: 0] to the recording head driving unit for each of the head arrays A and B, and the ink droplets are ejected. When the ejection is not performed, the first half and the second half of the head drive waveform Vcom can be selected by transmitting data with no image (all 0 corresponds in FIG. 12).

  In the ink jet recording apparatus according to the seventh embodiment of the present invention, the recording head control unit 106 has the head arrays A and B in accordance with an instruction from the CPU 102 as the control unit that has read the test pattern execution program stored in the ROM 103 as the storage unit in advance. A test pattern generation function for printing on a recording medium by discharging ink droplets from the ink discharge ports in the head arrays A and B while changing the delay time within the drive cycle in order to measure the ink droplet landing position deviation between Thus, an adjustment setting is made so as to eliminate the deviation of the ink droplet landing positions between the head arrays.

  FIG. 13 shows a print example of a test pattern on a recording medium for measuring the deviation of the ink droplet landing position by the recording head controller 106 of the ink jet recording apparatus according to the seventh embodiment of the present invention, including the head driving waveform Vcom. It is the shown schematic diagram.

  Referring to FIG. 13, here, the recording head control unit 106 changes the value of Delay (delay time) within the driving cycle to eject ink droplets from the head arrays A and B, thereby forming a plurality of lines (line segments). The state of the test pattern printed on the recording medium in increments of 5 μm from −20 μm to +20 μm is shown. Here, the overlapping line of the print line of the head row A and the print line of the head row B represents the deviation amount of the ink droplet landing position, and FIG. 13 shows the case where it is +10 μm. Therefore, the recording head control unit 106 can set the delay (delay time) value to be +10 μm to eliminate the deviation of the ink droplet landing position.

  In the ink jet recording apparatus according to the eighth embodiment of the present invention, the CPU 102 as the control unit displays the ink droplet landing position deviation information with respect to the RAM 104 which is a nonvolatile memory based on the test pattern generation result generated in the seventh embodiment. Set and memorize it, or update the ink droplet landing position deviation information that has already been memorized, so that it can be operated when head arrays A and B are replaced or when there is a change over time The user can adjust the deviation of the ink droplet landing position between the head arrays A and B from a panel or the like.

  FIG. 14 is a diagram illustrating a non-volatile configuration based on a test pattern generation result for measuring a deviation amount of an ink droplet landing position in the recording head control unit 106 under the control of the CPU 102 in accordance with a user operation instruction of the inkjet recording apparatus according to the eighth embodiment of the present invention. It is the flowchart which showed the operation | movement process which leads to memory | storage to memory (RAM104).

  Referring to FIG. 14, in the control operation process related to the CPU 102 of the ink jet recording apparatus, first, the user selects a test pattern output from the menu on the operation panel (step S <b> 1), so that the CPU 102 stores the test pattern execution program from the ROM 103. As a result of instructing the recording head control unit 106 to measure the deviation amount of the ink droplet landing position, the test pattern printing execution (step S2) is performed.

  Therefore, after the user performs a process of visually confirming a value (step S3) in which the print location of the head row A and the print location of the head row B of the test pattern on the recording medium match, The confirmed value is input (step S4), and the value input by the user is recorded in the nonvolatile memory (RAM 104) by the CPU 102 (step S5), and then the operation ends. When the input value is recorded in the RAM 104, either the ink droplet landing position deviation information is set and stored as described above, or the already stored ink droplet landing position deviation information is updated. This is true.

  The ink jet recording apparatus according to the ninth embodiment of the present invention includes a test pattern reading unit (sensor) that reads a test pattern generation result on a recording medium by the recording head control unit 106, and the CPU 102 reads a test read by the sensor. Based on the pattern generation result, the ink droplet landing position deviation information is set to the RAM 104 or the ink droplet landing position deviation information is updated, so that the test pattern is automatically read between the head arrays A and B by a sensor or the like. It is possible to adjust the deviation of the ink droplet landing position.

  FIG. 15 is a schematic diagram for explaining the reading of the test pattern on the recording medium by the test pattern reading unit 208 provided in the ink jet recording apparatus according to the ninth embodiment of the invention.

  Referring to FIG. 15, here, the test pattern on the recording medium as shown in FIG. 13 is read by the test pattern reading unit 208 using a sensor to detect the deviation amount of the ink droplet landing position, and the ink detected by the CPU 102 is detected. Indicates that the ink droplet landing position deviation information stored in the RAM 104, which is a nonvolatile memory, is set based on the deviation amount of the droplet landing position, or the ink droplet landing position deviation information already stored is updated. ing.

  FIG. 16 illustrates a nonvolatile memory (RAM 104) based on a test pattern generation result for measuring the amount of deviation of ink droplet landing positions in the recording head controller 106 by the automatic control of the CPU 102 of the inkjet recording apparatus according to the ninth embodiment. It is the flowchart which showed the operation | movement process which leads to memory | storage.

  Referring to FIG. 16, in the automatic control operation process related to the CPU 102 of the inkjet recording apparatus, first, the user selects a test pattern output from the menu on the operation panel (step S <b> 1), so that the CPU 102 executes the test pattern from the ROM 103. As a result of reading the program and instructing the recording head control unit 106 to measure the deviation amount of the ink droplet landing position, the test pattern printing execution (step S2) is performed.

  Therefore, the CPU 102 performs processing for confirming (step S3) the test pattern reading unit 208 for a value at which the print position of the head array A and the print position of the head array B coincide with each other on the recording medium. The operation ends after the process of recording the value confirmed by the test pattern reading unit 208 in the nonvolatile memory (RAM 104) (step S4). Again, when the value confirmed by the test pattern reading unit 208 is recorded in the RAM 104, the deviation information of the ink droplet landing position is set and stored as described above, or the ink droplet landing position already stored is stored. This corresponds to any of cases where the deviation information is updated.

  In the ink jet recording apparatus according to each of the embodiments described above, the case where two head arrays A and B are configured using eight recording heads 1 to 8 as a line head system has been described. Since it can be arbitrarily changed, the ink jet recording apparatus of the present invention is not limited to the form disclosed in each embodiment.

101 Host PC (personal computer)
102 CPU
103 ROM
104 RAM
105 Host I / F (interface)
DESCRIPTION OF SYMBOLS 106 Recording head control part 107 Subscanning control part 108 Subscanning encoder 109 Subscanning motor 110 Common bus 111-118 Recording head 1-8 drive part 201 Image data shift register 202 Image data latch part 203 Mask pattern shift register 204 Mask pattern latch Unit 205 gradation decoder 206 level shifter 207 analog switch 208 test pattern reading unit

JP 2006-27161 A

Claims (10)

In a line head type inkjet recording apparatus having a configuration in which a plurality of recording heads are arranged so as to be equal to or larger than the width of the recording medium in the main scanning direction and are arranged in parallel in a head row in the sub scanning direction,
Non-volatile storage means for storing misalignment information of ink droplet landing positions between the head arrays at the time of mounting, in which the plurality of recording heads are juxtaposed as the head arrays, and ink from each ink discharge port of the plurality of recording heads A plurality of head drive waveforms for ejecting droplets are generated within a preset drive cycle of the sub-scanning resolution in the recording medium conveyance direction, and the head drive waveform is selected based on deviation information of the ink droplet landing positions A plurality of recording head driving means for driving the plurality of recording heads based on the head driving waveform selected by the recording head control means; An ink jet recording apparatus comprising: The inkjet recording apparatus according to claim 1, wherein
When the recording head control unit generates a plurality of the head driving waveforms within the driving period of the sub-scanning resolution, the recording head control unit sets the second and subsequent time intervals with a delay time set from the output of the first head driving waveform. An ink jet recording apparatus that outputs a head driving waveform. The inkjet recording apparatus according to claim 2.
The ink jet recording apparatus, wherein the recording head control means sets the delay time at a fixed value based on deviation information of the ink droplet landing positions stored in the storage means. The inkjet recording apparatus according to claim 2.
The ink jet recording apparatus, wherein the recording head control unit performs the setting of the delay time based on deviation information of the ink droplet landing position and immediately preceding sub-scanning encoder cycle information stored in the storage unit. The inkjet recording apparatus according to claim 1, wherein
The ink jet recording apparatus, wherein the recording head control means includes a plurality of head driving waveform generation units for generating a plurality of the head driving waveforms within the driving period of the sub-scanning resolution. The inkjet recording apparatus according to claim 1, wherein
The recording head control means transmits the head driving mask pattern serial transfer data to the recording head driving unit for each of the head arrays by selecting head driving mask pattern serial transfer data when selecting the plurality of head driving waveforms. An ink jet recording apparatus that masks a period during which a head driving waveform that does not eject ink droplets is input by the recording head driving unit that has received transfer data. The inkjet recording apparatus according to claim 1, wherein
When the recording head control means selects the plurality of head driving waveforms, non-ejection head driving is performed during a period in which the head driving waveform is not ejected in the recording head driving unit for each head row. An ink jet recording apparatus that transfers data to the recording head driving unit. The inkjet recording apparatus according to claim 1, wherein
The recording head control means sets a delay time within the driving cycle in order to measure the ink droplet landing position deviation between the head arrays in accordance with an instruction from the control means that has read a test pattern execution program stored in advance in the storage means. An ink jet recording apparatus having a test pattern generation function for printing on the recording medium by ejecting the ink droplets from the ink ejection openings in the head row. The ink jet recording apparatus according to claim 8.
The control means sets and stores deviation information of the ink droplet landing position in the storage means based on the test pattern generation result by the recording head control means, or the already stored ink droplets An ink jet recording apparatus that updates deviation information of landing positions. The inkjet recording apparatus according to claim 9, wherein
A test pattern reading unit for reading the test pattern generation result;
The control means sets deviation information of the ink droplet landing position with respect to the storage means or updates the deviation information of the ink droplet landing position based on the generation result of the test pattern read by the test pattern reading unit. An ink jet recording apparatus.