JP2005262523A - Inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a proper recovery operation while suppressing wasteful ink consumption in the recovery operation. <P>SOLUTION: A preejection recovery means for making a plurality of ink nozzles 33 preeject ink in a proper order is provided so as to make the ejection states of the plurality of ink nozzles 33 recover to initial states. Foreign matters 14 and 15 in an ink supply chamber 32 of a print head 30 are kept in the state of nonejection to the printing area by being moved in the outward direction of a printing area in the preejection recovery operation, so that the quantity of the ink consumed by a head recovery means 40 can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus that forms an image by ejecting ink onto a recording medium from a plurality of ink nozzles provided in a print head.

  As one of output devices for computers and workstations, there is known an ink jet recording apparatus that forms an image by ejecting ink onto a recording medium such as recording paper. In this ink jet recording apparatus, a print head is mounted on a carriage that reciprocates in the main scanning direction, and ink is ejected to a recording medium from a plurality of ink nozzles provided in the print head at an appropriate timing. Some are configured, and others are configured such that the print head is fixed to the main body of the ink jet recording apparatus and ink is ejected to the recording medium to be conveyed.

  For example, the print head 1 shown in FIG. 17 has a hollow cavity-shaped ink supply chamber 2 that expands in the left-right direction in the figure, and the ink guided from an ink tank (not shown in the figure) The ink is once sent into the ink supply chamber 2. The ink supply chamber 2 has a hollow shape that rapidly expands toward the recording medium side on the lower side in the figure, and an enlarged part on the lower side in the figure branches into a large number of small passages and extends. It is formed in the ink nozzles 3, 3,. These many ink nozzles 3, 3,... Are arranged in a line so as to form a substantially straight line, and the ink once stored in the ink supply chamber 2 is the ink nozzle 3. , 3... Are discharged.

  As described above, since the ink jet recording apparatus forms an image by directly ejecting ink from the print head 1, the ink is always normally ejected from each ink nozzle 3 provided in the print head 1. It is necessary to keep it. However, in the ink supply chamber 2 described above, bubbles 4 generated from gas components dissolved in the ink or bubbles generated when ink is ejected may remain. In addition, when the print head 1 is manufactured, dust 5 made of a mold, an adhesive, or the like may remain in the print head 1. There is a risk of hindering the discharge operation.

  For this reason, the ink jet recording apparatus is often provided with a head recovery means. The head recovery means discharges foreign matters such as bubbles 4 and dust 5 remaining in the ink nozzle 3 and the ink supply chamber 2 by applying a negative pressure to the discharge port of the ink nozzle 3 to suck the ink. Suction recovery means, preliminary discharge recovery means for discharging foreign matter existing in the ink supply chamber 2 and the ink nozzle 3 by preliminary discharge of ink from each ink nozzle 3, or the face surface 3a of the ink nozzle 3 In this configuration, wiping means for wiping off paper dust or ink adhering to the ink is included.

  However, in recent inkjet recording apparatuses, the number of ink nozzles is increased and the nozzle diameter is miniaturized as the resolution is increased, and accordingly, the ink supply chamber 2 and the ink nozzles in the print head 1 are increased. 3 tends to increase the amount of foreign matter 4, 5 present in 3. Then, in order to remove the foreign matters 4 and 5, the amount of ink discharged by the head recovery means described above tends to increase, in particular, the amount of ink consumed by the suction recovery means tends to increase. It is getting more. In addition, when the outer diameter (for example, 20 μm to 50 μm) of the foreign matter 4 or 5 is larger than the inner diameter of the ink nozzle 3, it is impossible to suck and remove the so-called non-ejection nozzle. There is also.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ink jet recording apparatus capable of executing a good recovery operation while suppressing wasteful ink consumption during the recovery operation.

  In order to achieve the above object, in the ink jet recording apparatus according to claim 1 of the present invention, a plurality of ink nozzles branched and extending from an ink supply chamber provided in the print head are arranged in a line. In the ink jet recording apparatus provided with the head recovery means for recovering the ejection state of each ink nozzle to the initial state by pre-discharging the ink from each ink nozzle, the head recovery means includes the plurality of inks Preliminary ejection recovery means for moving foreign matter in the ink supply chamber by preliminarily ejecting the nozzles in an appropriate order is provided.

  According to the ink jet recording apparatus according to claim 1 having such a configuration, for example, as in the ink jet recording apparatus according to claim 2 of the present invention, the preliminary ejection recovery means is provided at one end side in the column direction of each ink nozzle. In this configuration, the foreign matter that originally existed randomly in the ink supply chamber is sequentially moved in one direction by being preliminarily ejected sequentially from the ink nozzle toward the ink nozzle on the other end side. Thus, for example, the ink is not discharged into the print area by being pushed out of the print area. Accordingly, the amount of ink sucked in the suction recovery operation performed next to the preliminary discharge recovery operation can be very small, and as a result, the total ink consumption by the head recovery means can be greatly reduced. It has become.

  Further, in the ink jet recording apparatus according to claim 3 of the present invention, when the preliminary ejection recovery means in claim 1 causes the plurality of ink nozzles to perform preliminary ejection, the both end portions in the row direction of the plurality of ink nozzles are arranged. The first preliminary ejection is performed by the ink nozzles, and then the preliminary ejection is performed sequentially from the central ink nozzle in the column direction of the plurality of ink nozzles toward the outer ink nozzles. Yes.

  According to the ink jet recording apparatus of the third aspect having such a configuration, first, the preliminary ejection from the ink nozzles at both ends in the parallel direction of the plurality of ink nozzles is performed, thereby the foreign matter in the ink supply chamber. The foreign matter in the ink supply chamber that has started to move toward the outside of the printing area and started to move in the same direction is further preliminarily ejected from the central portion of the plurality of ink nozzles toward both outward sides. The ink nozzle moves favorably toward the outside of the print area at both ends of the ink nozzle.

  Furthermore, in an ink jet recording apparatus according to a fourth aspect of the present invention, in the second or third aspect, the ink nozzles at both ends in the row direction of the ink nozzles are placed outside the print area so as not to be used for the print operation. It is formed on a nozzle for capturing foreign matter or a nozzle for discharging foreign matter.

  According to the ink jet recording apparatus of the fourth aspect having such a configuration, the foreign matter sent to the outside of the printing region is taken in and held by a foreign matter capturing nozzle not used for printing, or for foreign matter discharge. By discharging to the outside through the nozzle, adverse effects due to foreign matter on the recording operation of the print head are surely prevented.

  Furthermore, in the ink jet recording apparatus according to a fifth aspect of the present invention, the preliminary ejection recovery means according to any one of the first to third aspects provides a preliminary ejection amount in the first half in the preliminary ejection operation from a plurality of ink nozzles. Is large and the preliminary discharge amount in the latter half is set small.

  According to the ink jet recording apparatus of the fifth aspect having such a configuration, since the preliminary discharge amount in the first half is set large, the foreign matter in the ink supply chamber starts to move favorably toward the outside of the print area. At the same time, the foreign matter that has once started to move is favorably moved even by a small amount of preliminary discharge, so that the overall consumption of the preliminary discharge operation can be kept small.

  On the other hand, in the ink jet recording apparatus according to claim 6 of the present invention, the head recovery means in claim 1 is configured to perform a suction recovery operation by suction to each ink nozzle after the preliminary discharge operation by the preliminary discharge recovery means. Yes.

  According to the ink jet recording apparatus of the sixth aspect having such a configuration, the ink or the like thickened in the ink nozzles is favorably eliminated by the suction recovery operation after the preliminary ejection operation.

  As described above, the ink jet recording apparatus according to the first aspect of the present invention provides a plurality of ink nozzles that are preliminarily ejected in an appropriate order to the head recovery means that restores the ejection state of each of the plurality of ink nozzles to the initial state. For example, as in the ink jet recording apparatus according to claim 2 of the present invention, the preliminary ejection recovery means is arranged so that the preliminary ejection recovery means is directed from the ink nozzle on one end side to the ink nozzle on the other end side in the row direction of each ink nozzle. In this way, the foreign matter in the ink supply chamber of the print head is moved toward the outside of the print area during the pre-discharge recovery operation so that the foreign matter is not discharged into the print area and the head is recovered. Since it is configured to reduce the amount of ink consumed by the means, it is particularly wasted during the recovery operation. It is possible to suppress ink consumption, it is possible to improve the usefulness of the ink jet recording apparatus.

  According to a third aspect of the present invention, there is provided the ink jet recording apparatus, wherein the preliminary ejection recovery means in the first aspect performs preliminary ejection on the ink nozzles at both ends in the row direction of the plurality of ink nozzles, and thereafter By making preliminary discharge sequentially from the center nozzle to both outer ink nozzles, the foreign matter in the ink supply chamber is first moved outward from the print area and then moved in the same direction. Since the foreign matter in the ink supply chamber that has started is configured to move favorably toward the outside of the print area, the above-described effects can be further enhanced.

  Furthermore, an ink jet recording apparatus according to a fourth aspect of the present invention is used for a printing operation in which the ink nozzles at both ends in the row direction of the plurality of ink nozzles according to the second or third aspect are arranged outside the printing area. The foreign matter that has been sent to the outside of the print area is held inside, or discharged outside to prevent adverse effects on the recording of the print head. Therefore, the above-described effect can be obtained with certainty.

  Furthermore, an ink jet recording apparatus according to a fifth aspect of the present invention provides the preliminary ejection amount in the preliminary ejection operation from the plurality of ink nozzles in the preliminary ejection recovery means according to any one of the first to third aspects. Large, set the amount of preliminary discharge in the second half small, and start moving the foreign matter in the ink supply chamber well toward the outside of the print area, and move the foreign matter once started smoothly with a small amount of preliminary discharge Thus, the above-described effects can be further improved because the overall consumption of the preliminary ejection operation is reduced.

  On the other hand, in an ink jet recording apparatus according to a sixth aspect of the present invention, the head recovery means in the first aspect is configured to perform a suction recovery operation by suction to each ink nozzle after the preliminary discharge operation by the preliminary discharge recovery means. In addition to the above-described effects, the function of the print head can be maintained extremely well because the ink that has been thickened in the ink nozzle by the suction recovery operation after the operation is preferably eliminated.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Prior to that, the overall structure of a printer as an ink jet recording apparatus will be outlined.

  In other words, the printer 20 shown in FIG. 4 is provided with a platen 22 on which a recording medium 21 such as recording paper conveyed in the direction of arrow A (sub-scanning direction) is placed. A pair of scanning rails (guide rails) 23, 23 extending in parallel in a substantially horizontal direction is stretched over the upper position of the. A carriage 25 that reciprocates and scans the scanning rails 23 and 23 in the direction of arrow B (main scanning direction) perpendicular to the direction of arrow A by a motor and belt 24 (not shown) slides (not shown). It is attached via a bearing.

  Further, the carriage 25 is equipped with a print head 30 having an ink tank 26. In the print formation region, a desired print is performed by ink ejected from the print head 30 toward the recording paper 21 on the lower side in the figure. An image is formed.

  The print head 30 is configured as shown in FIG. 5, for example. That is, an ink supply path 31 extending from the above-described ink tank 26 is provided at the inner central portion of the print head 30 so as to extend downward in the figure, and from the lower end portion of the ink supply path 31, A cavity-shaped ink supply chamber 32 is formed which expands rapidly toward both outer sides in the sub-scanning direction (left-right direction in the figure). Ink in the ink tank 26 is fed into the ink supply chamber 32 through the ink supply path 31.

  The ink supply chamber 32 has a hollow shape that rapidly expands toward the recording medium side disposed on the lower side in the drawing, and the space portion on the lower end side in the drawing after the expansion is branched into a small passage. As a result, a large number of ink nozzles 33 are formed. Each of these many ink nozzles 33, 33,... Extends linearly downward in the figure, and opens on a face surface 33 a formed on the lower end surface of the print head 30. . .. Are arranged in a line so as to form a substantially straight line along the sub-scanning direction (the left-right direction in the drawing). The ink supplied from the ink supply chamber 32 to each ink nozzle 33 is appropriately discharged under the heating control of a heater (not shown) attached to each ink nozzle 33.

  Of the large number of ink nozzles 33, 33,... Arranged in a row along the sub-scanning direction (the left-right direction in the figure) in this way, A pair of dummy ink nozzles 33b and 33b that are not used for the printing operation are provided. Each of these dummy nozzles 33b is originally provided in order to reliably recover the other ink nozzles 33 used for printing at the time of suction recovery. Are also provided as foreign matter capturing nozzles for taking in foreign matters 14 and 15.

  Returning to FIG. 4 again, the above-described plotter 20 is provided with a head recovery means 40 for keeping the ink nozzles 33 of the print head 30 to normally eject ink normally. The head recovery means 40 is disposed on one side (left side in the figure) of the range in which the carriage 25 is movable, that is, at a position away from the print formation region by an appropriate distance in the main scanning direction. More specifically, air bubbles 14 and dust remaining in the ink nozzle 33 and the ink supply chamber 32 are sucked by applying a negative pressure to the discharge port of each ink nozzle 33 of the print head 30 described above. Suction recovery means for discharging foreign matters such as 15 to the outside, and foreign matters 14 and 15 existing in the ink supply chamber 32 and the ink nozzle 33 by preliminarily discharging ink from the ink nozzles 33 at an appropriate timing. It is configured to include a cap that receives ink preliminarily ejected when the preliminary ejection recovery unit that discharges to the outside is executed, and a wiping unit that wipes off paper dust and ink adhering to the face surface 33a of the ink nozzle 33. Yes.

  Here, the preliminary ejection recovery means has a function of preliminarily ejecting each of the plurality of ink nozzles 33 in the above-described print head 30 in an appropriate order by a control device which will be described later. In the ink supply chamber 32, the foreign matter such as bubbles 14 and dust 15 is moved to the outside of the printing area.

  That is, the preliminary ejection recovery means has a function of preliminary ejecting the plurality of ink nozzles 33 provided in the print head 30 in an appropriate order along their arrangement direction (sub-scanning direction). Specifically, as shown in FIGS. 1, 2 and 3 according to the first embodiment of the present invention, a plurality of ink nozzles 33, 33. By sequentially performing preliminary ejection sequentially from the left end side (shown in the drawing) toward the other end side (shown in the right end side), the foreign substances 14 and 15 (see FIG. 1) that were initially randomly present in the ink supply chamber 32 are removed from the ink. The nozzle 33 sequentially moves toward the other end side (the right end side in the figure) of the nozzle 33 (see FIG. 2), and finally, it is pushed out of the outermost printing area (FIG. 3). reference). At this time, from one ink nozzle 13, for example, 30 pl (picoliter) of ink is ejected while being shifted by an interval of 10 ms.

  As described above, according to the first embodiment of the present invention, the preliminary ejection recovery operation does not eject simultaneously from a plurality of nozzles, but ejects in order, so that the inside of the ink supply chamber 32 provided in the print head 30 Ink flow (fluidization) occurs and the foreign substances 14 and 15 are smoothly pushed to the outside of the printing area, and the foreign substances 14 and 15 are not ejected from the ink nozzles 33 in the printing area. Accordingly, the amount of ink sucked by the suction recovery operation performed next to the preliminary ejection recovery operation can be extremely small, and as a result, the amount of ink consumed by the head recovery means 40 is greatly reduced. .

  On the other hand, in the preliminary ejection operation in the conventional apparatus, for example, as shown in FIG. 17 described above, the entire plurality of ink nozzles 3, 3,. Therefore, the foreign substances 4 and 5 in the ink supply chamber 2 are merely rotated and danced within a limited area, and are not moved or discharged as in the above-described embodiment of the present invention.

  Such a preliminary discharge operation in an appropriate order for each ink nozzle 33 is executed by, for example, the following discharge control device. That is, as shown in FIG. 6, the MPU 51 provided in the ejection control device 55 to which the recording signal is input through the interface 50 is used by the MPU 51 as shown in the flowchart shown in FIG. A program ROM 52 for storing a control program for performing a discharge operation and a dynamic RAM 53 for storing various data (such as the recording signal and recording data supplied to the head) are connected to the print head described above. Data transfer control between the interface 50, MPU 51, and RAM 53 is performed by a gate array 54 that controls supply of recording data to 30.

  Reference numeral 60 in the figure denotes a carrier motor for scanning the carriage 25, reference numeral 61 denotes a conveyance motor for conveying the recording paper, and reference numeral 62 denotes a print head 30. Reference numerals 63 and 64 denote motor drivers that drive the transport motor 61 and the carrier motor 60, respectively.

  Further, each part of the discharge control device 55 and the print head 30 is configured as shown in FIG. 7, for example. That is, the gate array 54 described above includes a data latch 541, a segment (SEG) shift register 542, a multiplexer (MPX) 543, a common (COM) timing generation circuit 544, and a decoder 545. On the other hand, the print head 30 has a diode matrix configuration, and a drive current flows through the discharge heaters (H1 to H64) where the common signal COM and the segment signal SEG coincide with each other, whereby the ink is heated and discharged.

  The decoder 545 decodes the timing generated by the common timing generation circuit 544 and selects any one of the common signals COM1 to COM8. The data latch 541 latches the recording data read from the RAM 53 in units of 8 bits, and the multiplexer 543 outputs the recording data as segment signals SEG 1 to 8 according to the segment shift register 542. The output from the multiplexer 543 can be variously changed depending on the contents of the shift register 542, such as 1-bit unit, 2-bit unit, or all 8 bits. With such a configuration, the preliminary ejection operation of each ink nozzle 33 in the print head 30 as described above is performed in an appropriate order along the arrangement direction (sub-scanning direction).

  When a recording signal is input from the interface 50 to the ejection control device 55 having such a configuration, the recording signal is converted into recording data for printing between the gate array 54 and the MPU 51. The motor drivers 63 and 64 are driven, and the print head 30 is driven in accordance with the recording data sent to the head driver 62 to perform printing.

  At that time, the preliminary ejection operation for each ink nozzle 33 of the print head 30 by the preliminary ejection recovery means as described above is performed. The specific procedure of the preliminary ejection is shown in FIGS. 8 and 9, for example. Become like that. That is, when ink ejection is started (step 1 in FIG. 8 and (a) in FIG. 9), first, ejection from the ink nozzle 331 arranged at the left end in the nozzle arrangement direction is performed (in FIG. 8). Step 2 and (b) of FIG. After an appropriate amount of ink is ejected, the ink is moved rightward by one dot and ejected by the adjacent ink nozzle 332 (step 3 in FIG. 8 and (c) in FIG. 9). Further, in the same manner, the ejection position sequentially moves toward the right side in the nozzle arrangement direction (FIG. 9D), and when ejection from the ink nozzle 333 disposed at the right end is performed (FIG. 9). Step 4 in FIG. 8 and (e) in FIG. 9), the preliminary discharge operation is terminated (Step 5 in FIG. 8 and (f) in FIG. 9).

  Next, in the second embodiment shown in FIG. 10, first, the dummy arranged at both end portions in the arrangement direction (sub-scanning direction) of the plurality of ink nozzles 33, 33,. The ink nozzles 33b and 33b are configured to perform preliminary ejection, whereby the foreign matter 14 and 15 in the ink supply chamber 32 is directed to both ends in the sub-scanning direction, that is, toward the outside of the print area. Start moving.

  Then, as shown in FIG. 11, preliminary ejection from the ink nozzles arranged in the central portion in the nozzle row direction of the plurality of ink nozzles 33, 33,... As shown in FIG. 13, preliminary ejection is sequentially performed toward both outer sides in the nozzle row direction of the plurality of ink nozzles 33, 33,. As a result, the foreign matter 14 and 15 in the ink supply chamber 32 that has started to move toward the outside of the printing area as described above further moves toward the outside of the printing area on both ends of the ink nozzles 33, 33,. And move smoothly. The discharge flow at this time is shown in FIGS.

  That is, in the second embodiment, when ink ejection is started as shown in FIGS. 14 and 15 (step 1 in FIG. 14 and (a) in FIG. 15), first, a plurality of ink discharges are performed. .. Are preliminarily ejected from the dummy ink nozzles 33b and 33b at both ends in the nozzle row direction (step 2 in FIG. 14 and (b) in FIG. 15), and by an appropriate amount. Is stopped after discharging (step 3 in FIG. 14 and (c) in FIG. 15). As a result, the foreign substances 14 and 15 in the ink supply chamber 32 begin to move outward from the print area.

  The foreign matter 14 and 15 in the ink supply chamber 32 that has started to move toward the outside of the printing area is further paired with a pair of ink nozzles 334 arranged at the center of the plurality of ink nozzles 33, 33,. , 334 (step 4 in FIG. 14 and (d) in FIG. 15), after an appropriate amount of ink is discharged, 1 is applied to the pair of ink nozzles 335, 335 on the left and right sides adjacent to them. .. By moving by the amount of dots (step 5 in FIG. 14 and (e) in FIG. 15), the foreign matter 14 toward the outside of the print area on both ends of the ink nozzles 33, 33,. 15 moves well.

  In this way, the ejection position of the ink nozzle 33 moves sequentially toward both sides in the nozzle arrangement direction while repeating the movement of one dot ((f) in FIG. 15), and reaches both ends to reach the ink nozzle. When the discharge from 33b, 33b is performed (step 6 in FIG. 14 and (g) in FIG. 15), the preliminary discharge operation is terminated (step 7 in FIG. 14 and (h) in FIG. 15).

  At this time, in the second embodiment described above, the dummy ink nozzles 33b for capturing foreign matter that are not used in the printing operation are disposed at both ends in the nozzle row direction of the ink nozzles 33, 33,. 33b is disposed, the foreign matter 14 and 15 moved to the outside of the printing area on one end side of the ink supply chamber 32 is taken in and held by the above-described dummy ink nozzles 33b and 33b for capturing the foreign matter. Thus, the adverse effects of the foreign substances 14 and 15 on the recording operation of the print head 30 are prevented (see FIG. 13).

  The foreign matter capturing ink nozzle 33b may have the same shape as the nozzle used for the printing operation. However, in order to capture the foreign matter, the upper side inner diameter is increased and the lower side inner diameter is increased. It is also possible to make it different from the printing nozzle, such as by making it thinner.

  On the other hand, in the third embodiment shown in FIG. 16, a printing operation similar to that of the above-described embodiment is performed on both end portions of the ink nozzles 33, 33,. Dummy ink nozzles 33b and 33b for capturing foreign matter that are not used are disposed, and ink nozzles 33c and 33c for discharging foreign matter are further adjacent to the outer sides of the dummy ink nozzles 33b and 33b for capturing the foreign matter. Each is arranged. In other words, these foreign matter discharging ink nozzles 33c, 33c are respectively arranged at the outermost end portions in the nozzle row direction of the above-described printing ink nozzles 33, 33,. Are formed so as to have an inner diameter (about 50 μm) larger than the inner diameter (about 20 μm) of normal ink nozzles 33 and dummy nozzles 33b used for printing, and thereby foreign substances 14 and 15 (outer diameter 20 μm). Through 50 μm).

  According to the third embodiment having such a configuration, the foreign matters 14 and 15 moved to the outside of the printing area on one end side of the ink supply chamber 32 are discharged to the outside through the foreign matter discharging ink nozzles 33c and 33c. Thus, the adverse effect of the foreign matter 14 and 15 on the recording operation of the print head 30 is prevented very well.

  In each of the above-described embodiments, when the preliminary discharge recovery means performs the preliminary discharge operation from the plurality of ink nozzles 33, 33,..., The preliminary discharge amount in the first half of the nozzle row is, for example, 32 pl (picoliter). If the preliminary discharge amount in the latter half of the nozzle row is set to be as small as 28 pl (picoliters), for example, the foreign substances 14 and 15 are moved without waste. That is, if the preliminary ejection amount in the first half is set large, the foreign matter 14 and 15 in the ink supply chamber 32 starts to move well toward the outside of the print area, and once the foreign matter 14 and 15 has started to move, Therefore, the movement is performed well even with a small amount of preliminary discharge, and the consumption amount as a whole of the preliminary discharge operation is suppressed to be small.

  Further, if the suction recovery means of the head recovery means 40 performs suction to the ink nozzles 33, 33,... After the preliminary discharge operation by the preliminary discharge recovery means, the viscosity increases in the print head 30. The foreign substances 14 and 15 such as ink are well removed by the suction recovery operation after the preliminary ejection operation.

  The invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  For example, in the above-described embodiment, the present invention is applied to a printer of a type in which the head scans left and right. However, the present invention is not limited thereto, and the head is fixed and conveyed, for example. The present invention can be similarly applied to various other ink jet recording apparatuses such as a printer of a type that prints an image on a recording medium.

FIG. 2 is an enlarged vertical cross-sectional explanatory view of the print head in an enlarged view of the structure of the print head in the first embodiment of the present invention and showing an initial stage of a preliminary discharge operation. FIG. 2 is an enlarged longitudinal sectional explanatory view of a print head showing a next stage of a preliminary discharge operation in the ink jet recording apparatus shown in FIG. 1. FIG. 4 is an enlarged longitudinal sectional explanatory view of a print head showing a further stage of a preliminary discharge operation in the ink jet recording apparatus shown in FIG. 2. 1 is an external perspective view illustrating an overall structure of an ink jet recording apparatus according to an embodiment of the present invention. It is a longitudinal cross-sectional explanatory drawing which expanded and represented the structure of the print head to which this invention is applied. FIG. 2 is a block diagram illustrating a schematic configuration of an ejection control apparatus that performs an ink ejection operation from an ink nozzle of a print head. It is a block diagram showing the detailed structure in the principal part of the discharge control apparatus shown in FIG. It is a flowchart of the preliminary discharge operation in 1st Embodiment. FIG. 9 is an array diagram schematically showing the positions of discharge nozzles corresponding to the preliminary discharge flow of FIG. 8. FIG. 10 is an enlarged vertical cross-sectional explanatory view of a print head showing a first stage of a preliminary discharge operation of an ink jet recording apparatus according to a second embodiment of the present invention. FIG. 11 is an enlarged vertical cross-sectional explanatory view showing a next stage of a preliminary discharge operation in the ink jet recording apparatus shown in FIG. 10. FIG. 12 is an enlarged longitudinal sectional explanatory view of a print head showing a further next stage of the preliminary ejection operation in the ink jet recording apparatus shown in FIGS. 10 and 11. FIG. 13 is an enlarged longitudinal sectional explanatory view of a print head showing a further next stage of a preliminary discharge operation in the ink jet recording apparatus shown in FIGS. 10, 11 and 12. It is a flowchart of the preliminary discharge operation in 2nd Embodiment. FIG. 15 is an array diagram schematically showing the positions of discharge nozzles corresponding to the preliminary discharge flow of FIG. 14. FIG. 10 is an explanatory longitudinal sectional view illustrating an enlarged structure of a print head according to a third embodiment of the present invention. It is a longitudinal cross-sectional explanatory drawing which expanded and represented the structure of the conventional print head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Printer 21 Recording medium 25 Carriage 26 Ink tank 30 Print head 31 Ink supply path 32 Ink supply chamber 33 Ink nozzle 33a Face surface 33b Dummy nozzle 33c Foreign matter discharge ink nozzle 14, 15 Foreign matter 40 Head recovery means

Claims (6)

A plurality of ink nozzles branched and extending from an ink supply chamber provided in the print head are arranged in a row,
In the ink jet recording apparatus provided with the head recovery means for recovering the ejection state of each ink nozzle to the initial state by preliminarily ejecting ink from each ink nozzle,
2. An ink jet recording apparatus according to claim 1, wherein said head recovery means is provided with preliminary discharge recovery means for moving foreign matter in said ink supply chamber by preliminary discharge of said plurality of ink nozzles in an appropriate order.   2. The preliminary ejection recovery means is configured to sequentially perform preliminary ejection from an ink nozzle on one end side in the column direction of each ink nozzle toward an ink nozzle on the other end side. The ink jet recording apparatus described.   The preliminary ejection recovery means causes the ink nozzles at both ends in the column direction of the plurality of ink nozzles to perform first preliminary ejection when causing the plurality of ink nozzles to perform preliminary ejection, and then the plurality of ink nozzles. 2. The ink jet recording apparatus according to claim 1, wherein preliminary ejection is sequentially performed from an ink nozzle at a central portion in a nozzle row direction toward ink nozzles on both outer sides.   4. The ink jet recording apparatus according to claim 2, wherein the ink nozzles at both end portions in the row direction of the ink nozzles are formed as foreign matter capturing nozzles or foreign matter discharge nozzles.   4. The preliminary ejection recovery means, wherein the preliminary ejection amount in the first half is set large and the preliminary ejection amount in the second half is set small in the preliminary ejection operation from the plurality of ink nozzles. Any one of the inkjet recording apparatuses. 2. The head recovery means includes suction recovery means for performing a suction recovery operation for each of the plurality of ink nozzles after performing a preliminary discharge operation by the preliminary discharge recovery means. Inkjet recording apparatus.

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