JP2007190813A - Inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus capable of replacing a logistic ink filled in an inkjet print head with a recording ink under a condition having no influence on a head calibration without consuming a very large amount of the recording ink. <P>SOLUTION: The inkjet recording apparatus has a pH measuring mechanism for measuring the pH value of the ink in the inkjet print head after the logistic ink filled in the inkjet print head is replaced with the recording ink, a judging means for judging whether the pH value measured is normal or not, and a re-replacement control for performing re-replacement based on the result judged. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus, and more particularly, to a replacement method for replacing an inkjet print head filled with a distribution ink prepared for distribution using a PH sensor with a recording ink for recording.

  When a recording head equipped with either or both of pigment ink and dye ink is distributed, if the liquid chamber that supplies the ink of the recording head to the nozzles is filled with ink, the pigment ink and dye ink can be dried by drying the ink. Causes thickening and sticking, resulting in a phenomenon that is not recovered by initial printing when the ink jet print head is mounted and a significant deterioration in image quality.

  In order to solve this phenomenon, the components of the distribution ink filled in the liquid chamber of the ink jet print head are obtained by removing pigments and dyes, and have an ink composition suitable for head storage. This ink prevents thickening and sticking that have conventionally occurred.

An ink replacement sequence for replacing the distribution ink and the ink supplied from the ink cartridge is performed as an initial operation by the cleaning mechanism at the time of arrival. Thereafter, in order to further increase the replacement level, forced discharge processing and the like are also performed.
JP2003-341097 JP2002-283590

  However, in recent years, ink jet printing has been progressing due to an increase in flow resistance at the time of cleaning and a complicated flow path structure due to a decrease in discharge port diameter for realizing small droplets and an increase in ink color for expanding the color space reproduction region. There is a possibility that the amount of ink used for ink replacement varies from head to head. Ink supplied to the nozzles of the inkjet print head after ink replacement in this state remains a lot of high-viscosity evaporation inhibitor contained in the distribution ink, which may affect the ejection characteristics. there were.

  For this reason, a method of performing the ink replacement sequence under a condition having a sufficient margin in consideration of the above-described variation in the amount of ink used for ink replacement can be considered. However, in this method, a very large amount of ink is used for ink replacement. May be consumed.

  The purpose of the present invention is to replace the distribution ink filled in the inkjet print head with the recording ink so that it does not consume a very large amount of recording ink and does not affect the head calibration in order to solve the above-mentioned problems. An object of the present invention is to provide an ink jet recording apparatus capable of performing the above.

  In order to achieve the above object, the inkjet recording apparatus of the present invention comprises a PH measuring mechanism for measuring the ink PH value in the inkjet print head after replacing the physical distribution ink filled in the inkjet print head with the recording ink, and the measurement Determination means for determining whether the PH value is normal, and re-replacement control for performing re-replacement based on the determined result.

  As described above, the effect of the present invention is that the distribution ink filled in the ink jet print head can be replaced with the recording ink in a state that does not consume a very large amount of recording ink and does not affect the head calibration. Is to become.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  2 and 3 show a schematic configuration of a recording apparatus (printer) using the ink jet recording method. In FIG. 2, the outline of the apparatus main body 1 includes an exterior member including a lower case 2, an upper case 3, an access cover 4, and a recording paper discharge tray 5, and a chassis 6 (see FIG. 3) housed in the exterior member. Consists of

  Next, referring to FIG. 3, the recording operation mechanism in the present embodiment will be described. An automatic feeding mechanism 7 for automatically feeding a recording sheet as a recording medium into the apparatus main body, and a recording sheet sent from the automatic feeding mechanism 7 is guided to a predetermined recording position, and from the recording position to the discharge port 8. And a transport mechanism 9 that guides the recording paper, a recording mechanism that records on the recording paper transported to the recording position, and a cleaning mechanism 10 that performs a cleaning process on the recording mechanism.

  Here, the recording mechanism includes a carriage 12 movably supported by a carriage shaft 11 and an inkjet print head 13 (see FIG. 4) that is detachably mounted on the carriage 12.

  As shown in FIG. 4, the ink jet print head 13 includes an ink cartridge 14 that stores ink, and a discharge mechanism 15 that discharges ink supplied from the ink cartridge 14 from a discharge port. The ink cartridge 14 is an independent type for each color, and has a cartridge configuration that is detachably mounted on the inkjet print head 13 (see FIG. 5).

  As shown in the exploded perspective view of FIG. 6, the ink jet print head includes a recording element substrate 16, a first plate 17, an electric wiring substrate 18, a second plate 19, a tank holder 20, a flow path forming member 21, and a filter 22. The seal rubber 23 is used.

  The ink path will be described. Based on the recording information, the ink passes from the ink cartridge 14 through the ink flow path formed by the tank holder 20 and the flow path forming member 21, and via the ink flow path in the first plate 17, to the recording element substrate 16. It is discharged from the inner discharge port 16a. When ejecting ink, it is necessary to fill the ink path with the ink up to the tip of the ejection port.

  Next, referring to FIG. 7, a physical distribution form of the ink jet print head will be described. Inkjet print heads that have passed the ejection performance inspection are replaced with the above-mentioned ink in the ink flow path for the physical distribution, and the ink is replaced with the physical distribution ink that is suitable for storage of the head. Sealed at 104.

  The inkjet print head stored in a moisturized state in the packaging bag 104 is delivered to the user through a fashion trend while maintaining the stored state.

(Embodiment 1: PH measurement by ejected ink)
Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows the cleaning mechanism 10 of FIG. 10 in detail. The cleaning mechanism 10 is attached to the pump 110 for generating negative pressure and sucking ink in the ink jet print head, the cap 109 in contact with the ink jet print head at that time, and the discharge port surface of the ink jet print head after suction. It comprises a wiper 108 that removes ink, a preliminary ejection area 111 that ejects ink jet print heads during maintenance, and a PH measurement sensor 105 installed inside the area. A generally used glass electrode type PH sensor is used as the PH measurement sensor.

  FIG. 8 is an initial operation flowchart of the ink jet recording apparatus. First, in the head mounting, the user takes out the inkjet print head 13 from the packing bag 104 and mounts it on the carriage 12. Next, the ink cartridge 14 is mounted on the inkjet print head 13. Next, a cleaning flow (not shown) at the time of arrival described in JP-A-2002-283590 is performed, and the distribution ink filled in the flow path of the inkjet print head 13 is replaced with the recording ink of the ink cartridge 14. To do.

  However, there are cases in which replacement with recording ink cannot be performed completely due to an increase in flow resistance due to a reduction in the diameter of the discharge port or a complicated flow path shape due to an increase in the number of colors, in which case the discharge characteristics change. Therefore, the head calibration performed after this cannot be performed normally.

  Due to the problems described above, a means for detecting whether or not the replacement from the distribution ink to the recording ink is sufficiently performed to a level at which there is no problem when the head calibration is performed is necessary. In the present invention, attention is paid to the fact that the relationship between the PH value of the distribution ink and the recording ink is distribution ink <recording ink, and the distribution ink has a PH value of distribution ink ≧ 7.0. It is characterized by detecting the level.

  In FIG. 8, the embodiment of the present invention will be further described. Ink is ejected onto the PH measurement sensor 105 in order to detect the replacement level of the inkjet print head 13 that has been cleaned upon arrival. When the ink jet print head 13 is equipped with ink cartridges of a plurality of colors, it is preferable to perform discharge measurement for each color.

  Furthermore, as shown in FIG. 9, in an ink jet print head having a configuration in which the discharge nozzle row width is wider than the ink flow path width from the ink cartridge 14 to the discharge port, the ink near the discharge port end portion 16b when ink replacement is performed. It is clear from experiments that the ink stays and is not easily replaced. From this, it is possible to measure the replacement state with higher accuracy by discharging and measuring only the ink at the discharge port end portion 16b onto the PH measurement sensor 105.

  Next, the ink PH value on the PH measurement sensor 105 is measured, and compared with the original PH reference value of the recording ink measured in advance, and it is determined whether the replacement is sufficiently performed. Since the pH value changes depending on the temperature, the measurement environment temperature, preferably the measurement ink temperature, is measured and the value obtained by the PH measurement sensor is corrected. Furthermore, since the PH reference value is somewhat different for each recording ink color, it is necessary to have a plurality of values.

  If it is determined by the PH determination means that the ink replacement is at a sufficient level, the process proceeds to head calibration, and if it is determined to be insufficient, the process proceeds to re-replacement control. In the re-replacement control, the cleaning level at the time of re-replacement is read from a pre-stored table in accordance with the amount of deviation from the PH reference value calculated at the time of the PH determination means. This control makes it possible to suppress the amount of recording ink used for re-substitution as much as possible.

  The above-described PH determination means and re-replacement control are repeatedly performed, and after the inkjet print head 13 is sufficiently replaced with the recording ink, the process proceeds to head calibration. However, in rare cases, when a defective package during manufacture of an ink cartridge or an ink cartridge that has been left for a long time after being opened by a user is mounted on an ink jet print head at the time of ink replacement, the ink increases in viscosity and changes in PH value due to evaporation. Therefore, no matter how much the replacement is performed, the PH measurement value does not reach the PH reference value, and the replacement control is repeated until the ink cartridge is empty.

  In order to prevent the above problem, in this embodiment, a counter for counting the number of times of replacement is provided, and if the replacement control is repeated more than the set number of times, it is determined that the ink cartridge is abnormal and the initial operation is forced. When finished, the user is informed that the ink cartridge is abnormal by a message or the like, and is prompted to replace it with another normal ink cartridge.

  When the ink cartridge is replaced, the initial operation is repeated from the cleaning flow upon arrival.

(Embodiment 2: PH measurement with ink during cleaning)
As in the first embodiment, when ink is accumulated on the PH measurement sensor by ejection, if the ejection amount from each ejection nozzle is small, a large amount of ejection must be performed and measurement time may be increased. is there.

  Therefore, in the present invention, a PH sensor is provided in the cap as shown in FIG. 10A, or a PH sensor is provided in the tube from the cap to the waste liquid absorber as shown in FIG. The ink sucked from is measured.

  Further, when the ink jet print head is equipped with ink cartridges of a plurality of colors, the interior of the cap 109 is divided for each color as shown in FIG. Become.

  FIG. 11 is an initial operation flowchart of the ink jet recording apparatus of the present invention. Installation of the ink cartridge is the same as that in the first embodiment. Next, at the time of arrival cleaning, the sucked ink is left in the cap 109 as shown in FIG. 12A so that the PH sensor 105 can be measured.

  Next, the ink 114 on the PH sensor is measured. The measurement method and the correction method are the same as those in the first embodiment. When the measurement is completed, in order to prevent ink sticking on the cap, the ink 114 on the cap is quickly sucked into a state as shown in FIG.

  Subsequent reference value comparison, cleaning level selection, re-replacement count, etc. are all the same as in the first embodiment.

It is a detailed perspective view of Embodiment 1 of the present invention. 1 is a perspective view showing an external configuration of an ink jet recording apparatus suitable for the present invention. It is a perspective view which shows the state which removed the exterior member of the inkjet recording device shown in FIG. 1 is a perspective view showing an appearance of an ink jet print head suitable for the present invention. FIG. 5 is a perspective view showing a state where an ink cartridge is removed from the ink jet print head of FIG. 4. It is a perspective view which shows the state which the inkjet print head shown in FIG. 4 decomposed | disassembled. It is a perspective view which shows the packing state of the inkjet print head suitable for this invention. It is a flowchart which shows an example of Embodiment 1 of this invention. FIG. 3 is a cross-sectional view schematically showing an ink path from the ink cartridge to the ejection port according to the first embodiment of the present invention. It is sectional drawing which showed typically the cleaning mechanism of Embodiment 2 of this invention, (a) PH sensor installation in a cap, (b) PH sensor installation in a tube, (c) Multi-color correspondence was shown. It is. It is a flowchart which shows an example of Embodiment 2 of this invention. The state at the time of performing PH measurement in the cap of Embodiment 2 of the present invention is shown. The upper diagram shows the state at the time of PH measurement, and the lower diagram shows the state in which empty suction is performed after the measurement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 2 Lower case 3 Upper case 4 Access cover 5 Recording discharge tray 6 Chassis 7 Automatic conveyance mechanism 8 Discharge port 9 Conveyance mechanism 10 Cleaning mechanism 11 Carriage shaft 12 Carriage 13 Inkjet print head 14 Ink cartridge 15 Ejection mechanism 16 Recording element substrate 16a Discharge port 16b Discharge port end 17 First plate 18 Electric wiring board 19 Second plate 20 Tank holder 21 Flow path forming member 22 Filter 23 Seal rubber 104 Packing bag 105 PH sensor 108 Wiper 109 Cap 110 Pump 111 Pre-discharge Area 112 Waste liquid absorber 113 Tube 114 Ink

Claims (10)

  An ink jet recording apparatus comprising an ink jet print head provided with an energy element for discharging ink droplets and a nozzle for discharging ink, and an ink jet recording apparatus comprising a cleaning mechanism for the ink jet print head. An ink jet recording apparatus having a PH measuring mechanism for measuring a PH value.   The ink jet recording apparatus according to claim 1, wherein the ink jet print head is filled with a distribution ink.   3. The ink jet recording apparatus according to claim 2, further comprising a determination unit that determines a replacement state when the distribution ink in the ink jet print head is replaced with the recording ink by using the PH measurement mechanism.   The ink jet recording apparatus according to claim 1, wherein the sensor of the PH measuring mechanism is installed in a preliminary discharge port provided in a cleaning mechanism of the ink jet recording apparatus.   4. The ink jet recording according to claim 1, wherein the sensor of the PH measuring mechanism is installed in a cap provided in a cleaning mechanism of the ink jet recording apparatus or in a tube from the cap to the waste liquid absorber. apparatus.   The ink jet recording apparatus according to claim 1, wherein when ink is supplied by being discharged to the PH sensor, the ink is supplied only at an end portion of the discharge nozzle row.   6. The ink jet recording apparatus according to claim 1, further comprising a re-replacement control for performing replacement by cleaning or ejection when it is determined that the replacement is insufficient as a result of the determination by the determination unit.   The re-replacement control includes a control for performing a replacement level by cleaning or discharging by reading a table set in advance in the ink jet recording apparatus based on a value measured by a PH measurement mechanism. Item 8. The ink jet recording apparatus according to Item 7.   9. The re-replacement control has a counter and prompts the user to replace the ink cartridge when the PH value of the ink jet print head does not reach a satisfactory value even after a predetermined number of re-replacements. The ink jet recording apparatus described in 1.   2. The ink jet recording apparatus according to claim 1, wherein the relationship between the PH value of the distribution ink and the recording ink is distribution ink <recording ink, and the PH value of the distribution ink is distribution ink ≧ 7.0. .

Images