JP5064668B2 - Inkjet printer - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, and a facsimile, and more particularly to an ink jet printer provided with an ink cartridge that can facilitate positioning and fixing in a head unit.

  Conventionally, various ink cartridges have been proposed for ink cartridges used in printers, etc. In color ink jet printers capable of color printing, for example, four colors (black, magenta, yellow, and cyan) of ink are independently used. In general, the four ink cartridges filled are detachably attached to the head unit.

  Here, a head unit used for this type of color ink jet printer and mounted with an ink cartridge includes a single back wall, a pair of side walls connected to opposite ends of the back wall, and a gap between the side walls. A formed bottom wall and a plurality of partition walls are formed on the bottom wall. Further, a print head for discharging ink to the recording medium is mounted on the opposite surface of the recording medium on the bottom wall, and an ink supply communication port for supplying ink from the ink cartridge to the print head is provided on the bottom wall. It has been drilled.

  On the other hand, the ink cartridge is formed in a substantially rectangular parallelepiped shape, and an ink supply port for supplying ink is formed in the bottom wall of the ink cartridge. The ink supply port of the ink cartridge and the ink supply communication port of the head unit are mounted between the partition walls of the head unit so as to communicate with each other. Here, the carriage on which the ink cartridge and the head unit are mounted prints on a recording medium (recording paper or the like) by repeatedly reciprocating at an acceleration in a direction orthogonal to the conveyance direction of the recording medium.

  However, if the ink cartridge is not securely fixed to the head unit, the ink cartridge vibrates with the reciprocating movement of the carriage, and the ink is not smoothly supplied from the ink cartridge to the print head due to the vibration. It was a cause of hindrance to quality.

  In order to fix the head unit and the ink cartridge, a convex portion is provided on the rear wall of the head unit, and a concave portion is provided on the side wall of the ink cartridge facing the rear wall of the head unit. In this way, the convex portion of the head unit and the concave portion of the ink cartridge can be fitted, and the ink cartridge can be fixed to the head unit.

  However, in the above-described ink cartridge, since the concave portion provided in the side wall of the ink cartridge and the ink supply port provided in the bottom wall of the ink cartridge are provided in different planes, the ink cartridge is provided in the head unit. When mounting the head unit, it is necessary to first fit the convex portion of the head unit and the concave portion of the ink cartridge, and then fit the ink supply communication port of the head unit and the ink supply port of the ink cartridge. In addition, there is a problem that it is difficult to fit the ink supply communication port and the ink supply port.

  SUMMARY An advantage of some aspects of the invention is that it provides an ink jet printer including an ink cartridge that can be easily positioned and fixed in a head unit.

Ink according inkjet printer to claim 1 is provided with the ink ink supply port capable of supplying to the outside to be stored in the ink chamber of the storable ink storage chamber and its ink in order to achieve this objective An ink jet printer comprising: a cartridge; a carriage on which a head unit including a print head for printing on a recording medium is mounted; and a drive unit that reciprocally moves the carriage in a linear direction. The ink cartridge is mounted on the head unit. The ink cartridge includes a bottom wall, an upper wall facing the bottom wall, and a first recess formed for positioning the ink cartridge, and the ink is disposed on one end side of the ink cartridge. A supply port is formed, the first recess is formed on the other end side, and the head unit is mounted. A mounting portion for the ink cartridge is placed that, a fixing arm for fixing the ink cartridge placed on the placement section, the placing part, wherein the first recess is fitted a fitting protrusion for engagement, the ink supply port and the ink supply passage is provided for communicating, the fixed arm, while being swingably supported, the ink placed on the placement section When the carriage is moved, the ink cartridge rotates around the ink supply port by pressing the upper wall of the cartridge in the downward direction and fitting the first recess and the fitting protrusion. The ink cartridge is positioned while preventing the ink cartridge from being damaged.

  According to the ink jet printer of the first aspect, the ink stored in the ink storage chamber is supplied to the print head mounted on the head unit through the ink supply communication hole of the head unit connected to the ink supply port. Is done. Also, a first recess for positioning the ink cartridge is formed on the other end side of the surface on which the ink supply port is formed on one end side, and the first recess is fitted with a protrusion provided on the head unit. Combined.

The ink jet printer according to claim 2, wherein the ink cartridge is located at a position corresponding to a substantially central portion between the ink supply port and the first recess in the upper wall. The fixing arm has a locking claw that fits into the second recess, and the second recess of the ink cartridge mounted on the carriage in the movement direction of the carriage. A pair of side walls standing in the longitudinal direction of a pair of opposed surfaces facing each other in the moving direction are formed on both sides, and the distance between the pair of side walls in the moving direction is fitted in the second recess. It is formed in the same width as the locking claw .

  The ink jet printer according to claim 2 operates in the same manner as the ink jet printer according to claim 1, and is substantially at the center between the ink supply port and the first recess, and the ink supply port and the first recess are The second concave portion formed on the facing surface facing the formed surface is fitted with the convex portion of the pressing member that presses the ink cartridge.

Ink jet printer according to claim 3, wherein, in the ink jet printer according to claim 1 or claim 2, wherein the ink cartridge includes an air chamber having an outside air communication hole through outside air communication, the ink communicates to the air chamber a main reservoir with impregnable porous body, that is ink in the main reservoir chamber when in communication with the main reservoir co is divided into a sub-reservoir which communicates with the air chamber after being discharged .

According to the ink jet printer according to the third aspect, in addition to acting in the same manner as the ink jet printer according to the first or second aspect , the air that fills the air chamber through the outside air communication hole is the main reservoir chamber. After the ink impregnated in the porous body is discharged, the ink passes through the main storage chamber and enters the sub storage chamber, and the ink in the sub storage chamber is discharged.

The inkjet printer according to claim 4 is the inkjet printer according to claim 3 , wherein the outside air communication hole is provided on a surface on which the ink supply port and the first recess are formed, and the ink supply port and the first It arrange | positions between the recessed parts.

According to the ink jet printer described in claim 4 , the air acts in the same manner as the ink jet printer described in claim 3 , and the outside air is a surface on which the ink supply port and the first recess are formed, and the ink supply port It is supplied by an outside air communication hole provided between the first recess and the first recess.

  According to the ink jet printer of the first aspect, since the first recess is provided in the same plane as the ink supply port, the first recess is simultaneously performed when the ink supply port is fitted to the ink supply communication port of the head unit. The concave portion and the convex portion of the head unit can be fitted, and positioning in the head unit can be easily performed. In addition, since the first recess is formed at the end opposite to the ink supply port, the ink supply port provided at both ends and the first recess can be fixed to the head unit in a balanced manner. is there.

  According to the ink jet printer of the second aspect, in addition to the effect achieved by the ink jet printer of the first aspect, the upper wall is provided with the second concave portion, so that the second concave portion and the ink cartridge are pressed. It can be fixed to the head unit by fitting with the convex part of the arm. In addition, since the second recess is formed at the approximate center between the ink supply port and the first recess in the upper wall, the second recess, the ink supply port, and the first recess are substantially the second recess as the apex. It arrange | positions so that an isosceles triangle shape may be formed. Therefore, there is an effect that it can be fixed to the head unit with a good balance.

According to the ink jet printer according to claim 3, in addition to the effects of the ink jet printer according to claim 1 or claim 2, the air filled in the air chamber via the outside air communication hole has a main reservoir After the ink impregnated in the porous body is discharged, the ink passes through the main storage chamber and enters the sub storage chamber, and the ink in the sub storage chamber is discharged. Therefore, the ink in the sub storage chamber may be discharged last. it can. Therefore, for example, the auxiliary storage chamber is partitioned smaller than the main storage chamber, and the remaining amount of ink can be detected by an optical sensor or the like within the range of a small amount of ink stored in the small storage chamber. In addition, the presence or absence of ink can be detected.

According to the ink jet printer of the fourth aspect , in addition to the effect achieved by the ink jet printer of the third aspect , the outside air communication hole is provided with an ink supply port on the surface on which the ink supply port and the first recess are formed. Since the first recess is disposed between the first recess and the first recess, the first recess can be provided on the air chamber side. Therefore, even if the first recess is formed, there is an effect that it is possible to suppress a decrease in the capacity of the ink that can be stored in the ink storage chamber. Further, there is an effect that the first concave portion can be arranged farthest from the ink supply port.

  Preferred embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the image forming apparatus will be described using a color ink jet printer that includes four ink cartridges 2 that respectively store black, cyan, magenta, and yellow inks and that can perform color printing.

  FIG. 1 is a perspective view showing a schematic configuration of a main body of a color inkjet printer 1 according to a first embodiment of the present invention. The color inkjet printer 1 according to the first embodiment is non-perpendicular to the irradiated surface of the ink cartridge 2 (an inclination angle is approximately 10 degrees) in order to reduce a noise signal (unnecessary reflected light) from the irradiated surface of the ink cartridge 2. The ink sensor 19 is arranged so that light is irradiated to the ink sensor. The amount of reflected light detected by the ink sensor 19 is compared with the first threshold value and the second threshold value, and the presence or absence of ink and the ink cartridge are detected. It is configured so that the presence or absence of attachment can be determined and the detection position of the ink cartridge 2 can be corrected to accurately detect the amount of reflected light.

  The color inkjet printer 1 includes a head unit 4 including an ink cartridge 2 filled with four color inks of cyan, magenta, yellow, and black, and a print head 3 for printing on a recording medium P such as recording paper. A carriage 5 on which the ink cartridge 2 and the head unit 4 are mounted, a drive unit 6 that reciprocates the carriage 5 in a linear direction, and extends in the reciprocating direction of the carriage 5 and is disposed to face the print head 3. Platen roller 7, purge device 8, and ink sensor 19.

  Three partition plates 4c (see FIG. 2) are erected on the placement portion 4a of the head unit 4, and placed between the pair of side covers 4b formed on both sides of the placement portion 4a. The portion 4a is partitioned into mounting portions for four ink cartridges 2 through the respective partition plates 4c. Four ink cartridges 2 filled with cyan ink, magenta ink, yellow ink, and black ink are mounted on the mounting portion. The reason why the black ink cartridge 2a has a large volume with respect to each of the ink cartridges 2 filled with the other three colors of ink is that the frequency of use of the black ink is higher than that of the other colors. Is taken into account.

  The drive unit 6 includes a carriage shaft 9 disposed at the lower end portion of the carriage 5 and extending in parallel with the platen roller 7, a guide plate 10 disposed at the upper end portion of the carriage 5 and extending in parallel with the carriage shaft 9, and the carriage shaft 9. It consists of two pulleys 11 and 12 disposed between the guide plate 10 and at both ends of the carriage shaft 9, and an endless belt 13 spanned between these pulleys 11 and 12.

  When one pulley 11 is rotated forward and backward by driving a carriage motor (CR motor) 101, the carriage 5 joined to the endless belt 13 is moved along the carriage shaft along with the forward and reverse rotation of the pulley 11. 9 and the guide plate 10 are reciprocated in a linear direction.

  The recording medium P is fed from a paper feed cassette (not shown) provided on the side or lower side of the color ink jet printer 1 and is introduced between the print head 3 and the platen roller 7. Predetermined printing is performed by the ink ejected from the ink, and then the paper is discharged. In FIG. 1, the paper feed mechanism and paper discharge mechanism of the recording medium P are not shown.

  The purge device 8 is provided on the side of the platen roller 7 and is disposed so as to face the print head 3 when the head unit 4 is at the reset position. The purge device 8 includes a purge cap 14 that abuts against an opening surface of the nozzle so as to cover a plurality of nozzles (not shown) of the print head 3, a pump 15 and a cam 16, and an ink reservoir 17. When the head unit 4 is at the reset position, the nozzle of the print head 3 is covered with the purge cap 14, and defective ink containing bubbles and the like accumulated inside the print head 3 is driven by the pump 15 by driving the cam 16. By sucking, the print head 3 is recovered. The sucked defective ink is stored in the ink storage unit 17.

  A wiper member 20 is disposed adjacent to the purge device 8 at a position on the platen roller 7 side in the purge device 8. The wiper member 20 is formed in a spatula shape, and wipes the nozzle forming surface of the print head 3 as the carriage 5 moves. The cap 18 covers a plurality of nozzles of the print head 3 that is returned to the reset position when printing is completed in order to prevent ink from drying.

  The ink sensor 19 is a sensor for detecting the presence or absence of the ink cartridge 2 and the presence or absence of ink in the ink cartridge 2. It is provided near the end of the drive unit 6 (left side in FIG. 1), and includes an infrared light emitting element 19a (see FIG. 5) and an infrared light receiving element 19b (see FIG. 5). The light emitting surface of the infrared light emitting element 19a and the light receiving surface of the infrared light receiving element 19b are inclined at the same angle as the inclined portion 51a (see FIG. 4) inclined at approximately 20 degrees of the ink cartridge 2, Further, the ink cartridge 2 is disposed obliquely at an angle of approximately 10 degrees in the horizontal direction with respect to the inclined portion of the ink cartridge 2 (see FIG. 5). The light emitted from the infrared light emitting element 19a to the ink cartridge 2 is received as reflected light by the infrared light receiving element 19b. The presence or absence of the ink cartridge 2 or the presence or absence of ink in the ink cartridge 2 is detected based on the amount of the reflected light received.

  Next, with reference to FIG. 2, a fixing structure of each ink cartridge 2 mounted on the head unit 4 will be described. FIG. 2 is a side view showing a state where the ink cartridge 2 is mounted on the head unit 4, and shows a cross-sectional view of the head unit 4 and a part of the ink cartridge 2. In addition, the dashed-two dotted line in the figure has shown the state which the fixed arm 21 was flipped up.

  As described above, the head unit 4 is a member for detachably mounting the ink cartridge 2 and supplying ink to the print head 3, and mainly includes a placement portion 4 a and a fixed arm 21. . The placement portion 4a is a portion on which the ink cartridge 2 is placed, and is formed in a substantially flat surface shape. The placement portion 4a is partitioned into four spaces by three partition plates 4c, and each ink cartridge 2 is mounted between the partition plates 4c.

  An ink supply passage 22 communicating with the print head 3 is formed through the mounting portion 4a. The ink supply passage 22 communicates with the ink supply port 50 of the ink cartridge 2 while being sealed by an O-ring 23. Yes. By such communication, ink is supplied from the ink cartridge 2 to the print head 3. Further, a fitting convex portion 24 protrudes from the placement portion 4a on the side of the ink supply passage 22 (left side in FIG. 2). The fitting convex portion 24 is a member for positioning the ink cartridge 2 and will be described in detail later.

  A protrusion 4f for restricting the movement of the ink cartridge 2 in the vertical direction (vertical direction in FIG. 2) is formed behind the fitting convex portion 24 in the head unit 4 (left side in FIG. 2).

  The fixing arm 21 is a member for pressing and fixing the ink cartridge 2 downward in FIG. 2, and is pivotally supported above the head unit 4 (upper side in FIG. 2) so as to be swingable. One end side (left side in FIG. 2) of the fixed arm 21 is pivotally supported by a swing shaft 25, and an auxiliary spring member 26 is wound around the outer periphery of the swing shaft 25. One end of the auxiliary spring member 26 is locked to the spring locking portion 4 d of the head unit 4, and the other end is fixed to the fixed arm 21 with a biasing force acting on the fixed arm 21. Therefore, the fixed arm 21 is maintained in a state of being flipped upward (upward in FIG. 2) by the urging force of the auxiliary spring member 26 (two-dot chain line in the drawing), and therefore the ink cartridge 2 mounting portion of the head unit 4 Can be greatly opened, and the workability of the operator at the time of attaching and detaching the ink cartridge 2 can be improved.

  A stopper 27 that protrudes in a triangular shape in a side view is formed at the end of the fixed arm 21 (left side in FIG. 2). The stopper portion 27 is a portion for maintaining the fixed arm 21 in the ink cartridge fixed state. The fixed arm 21 is formed with a long hole 21a through which the swing shaft 25 is guided. The long hole 21a has a length necessary for removing the stopper portion 27 from the upper cover 4e. When the projection 21b formed on the fixed arm 21 is pushed, the fixed arm 21 moves downward in FIG. 2 through the long hole 21a, and the engagement between the upper cover 4e and the stopper portion 27 is released and the lever 21 is released. When the ink cartridge 2 is fixed, when the tip 21c of the fixed arm 21 in the state of the two-dot chain line in FIG. 2 is pushed down, the fixed arm 21 starts to rotate downward around the swing shaft 25. After the later-described pressing portion 28 and the upper wall 56 are in contact with each other, the fixed arm 21 rotates around the auxiliary spring member 26 around the contact point. When the stopper portion 27 moves from the lower position of the upper cover 4e to the right side of the end portion 4g of the upper cover 4e, the fixed arm 21 is rotated around the contact point between the pressing portion 28 and the upper wall 56, so 2 moves upward in FIG. 2 with respect to the swing shaft 25 by the long hole 21a formed in the arm 21, and the stopper portion 27 is locked to the end portion 4g of the upper cover 4e. Therefore, the state where the ink cartridge 2 is pressed by the pressing portion 28 and the locking claw 29 described later can be maintained.

  A pressing portion 28 is disposed on the lower surface side of the fixed arm 21 (the lower side in FIG. 2). The pressing portion 28 is a member for pressing the ink cartridge 2 downward (lower side in FIG. 2), and inside the pressing portion 28 is a compression spring (not shown) in an elastically compressed state. Is arranged. The pressing portion 28 is formed so as to be able to advance and retreat, and is normally held in a state of being advanced by a compression spring. As described above, when the fixed arm 21 is swung to the ink cartridge 2 side, the pressing portion 28 contacts the upper wall 56 of the ink cartridge 2 and moves backward. Therefore, the pressing portion 28 can apply an urging force to the ink cartridge 2 by the fixing stopper portion 27 and the compression spring, and can press the ink cartridge 2 downward (lower side in FIG. 2). It is.

  Further, a locking claw 29 is fixed to the lower surface side of the fixed arm 21 at the side of the pressing portion 28 (left side in FIG. 2). The locking claw 29 is a member for positioning the ink cartridge 2, and as shown in FIG. 2, a standing wall portion of a second fitting recess 57 described later and the locking claw 29 are in contact with each other. However, a gap is provided between the bottom of the second fitting recess 57 and the locking claw 29. Details of positioning will be described later.

  Next, the internal structure of the ink cartridge 2 will be described with reference to FIG. 3A is a side sectional view of the ink cartridge 2, FIG. 3B is a partial sectional view taken along line IIIb-IIIb in FIG. 3A, and FIG. 3C is an ink cartridge. FIG. FIG. 3A shows a state where ink is not stored in the ink cartridge 2.

  As shown in FIG. 3A, the ink cartridge 2 is formed in a substantially hollow box-like body, and the inside of the ink cartridge 2 is divided into air introduction chamber 43, main ink by partition walls 41,. It is partitioned into a storage chamber 44 and a sub ink storage chamber 45. The atmosphere introduction chamber 43 is a space for introducing the atmosphere into a main ink storage chamber 44 described later, and communicates with the atmosphere through an atmosphere communication port 47 formed through the bottom wall 46 of the ink cartridge 2. . On the other hand, the upper part (upper side in FIG. 3A) of the atmosphere introduction chamber 43 communicates with the main ink storage chamber 44, and the atmosphere is introduced into the main ink storage chamber 44 from the communication part.

The main ink storage chamber 44 is a substantially sealed space for storing ink, and stores a foam (porous body) 48 that can be impregnated with ink. An ink communication port 49 is formed through the partition wall 42 below the main ink storage chamber 44 (lower side in FIG. 3A). The main ink storage chamber 44 is connected to the ink communication port 49 via the ink communication port 49. It communicates with a sub ink storage chamber 45 described later. The foam 48 is composed of a sponge, a fiber material, or the like that can hold ink therein by utilizing a capillary phenomenon, and is stored in the main ink storage chamber 44 in a compressed state. Therefore, for example, when the ink cartridge 2 falls, the ink flows out from the main ink storage chamber 44 to the atmosphere introduction chamber 43, and the outflowed ink leaks out of the ink cartridge 2 from the atmosphere communication port 47. Can be prevented.

  The sub ink storage chamber 45 is a portion that stores ink and is irradiated with infrared light from the ink sensor 19 (see FIG. 4), and is a space substantially sealed at the side end of the ink cartridge 2. Is formed. The sub ink storage chamber 45 communicates with the main ink storage chamber 44 via the ink communication port 49 described above, and the ink stored in the main ink storage chamber 44 and the sub ink storage chamber 45 is stored in the ink cartridge 2. The ink is supplied to the print head 3 (see FIG. 2) through an ink supply port 50 formed through the bottom wall 46.

  The side wall 51 of the sub ink storage chamber 45 is formed with an inclined portion 51a inclined downward toward the main ink storage chamber 44. The inner surface side of the inclined portion 51a (the main ink storage chamber 44 side, FIG. On the left side of), a prism 52 is formed.

  The prism 52 is a member used for detecting the presence or absence of ink stored in the ink cartridge 2, and is formed integrally with the inclined portion 51a of the side wall 51 formed of a transparent light-transmitting material. ing. As the light transmissive material, for example, acrylic resin, polypropylene, polycarbonate, polystyrene, polyethylene, polyamide, methacryl, methylpentene polymer, glass and the like can be used. Moreover, the above-mentioned transparency does not mean that it is optically completely transparent, but also means that so-called translucency is included.

  As shown in FIG. 3B, the prism 52 includes a plurality of reflecting surfaces formed by alternately arranging peaks and valleys. The plurality of reflecting surfaces incline downward from one end side in the vertical direction of the inclined portion 51a (upper side in FIG. 3A) toward the other end side (lower side in FIG. 3A), and They are arranged in the thickness direction (perpendicular to the plane of FIG. 3A). Therefore, since ink can flow down on the prism 52, it is possible to prevent ink from remaining on the prism 52 and preventing desired reflected light from being obtained from the prism 52.

  Thus, by providing the prism 52 on the inner surface side (ink interface side, left side of FIG. 3B) of the inclined portion 51a, it is non-vertical from the direction facing the inclined portion 51a (in this embodiment, the inclination angle is substantially omitted). 10 degrees), infrared light can be emitted from the ink sensor 19 (see FIG. 5C). As a result, it is possible to prevent the infrared light receiving element 19b from detecting reflected light that is not related to the presence / absence detection of the ink reflected by the outer surface of the inclined surface 51a, and is necessary for the presence / absence detection of the ink. Thus, the reflected light from the prism 52 is mainly received, and the accuracy of detecting the presence or absence of ink is improved.

  The infrared light emitted from the infrared light emitting element 19a of the ink sensor 19 toward the inclined portion 51a generally has a predetermined beam angle (around ± 10 degrees). As a result, the luminous flux of infrared light spreads, and the amount of light per unit area irradiated on the inclined portion 51a decreases. Therefore, by arranging the prism 52 having a plurality of reflecting surfaces on the inclined portion 51a over almost the entire area of the inclined portion 51a, the irradiated infrared light can be reflected efficiently, and the infrared light of the ink sensor 2 can be reflected. Sufficient reflected light can be received by the light receiving element 19b. In the prism 52 of the present embodiment, as shown in FIG. 3B, the intersection angle of the ridge lines where the reflecting surfaces intersect is approximately 90 degrees, and 16 reflecting surfaces are formed. .

  A reflection member 53 is formed above the sub ink storage chamber 45 so as to face the above-described prism 52 with a predetermined interval. The reflecting member 53 is a member for changing the optical path of the infrared light transmitted into the sub ink storage chamber 45, and is formed in a bag shape having an air layer in the internal space while having a predetermined angle with the prism 52. Has been.

  According to the ink cartridge 2 configured as described above, when ink is consumed by the print head 3, air is introduced from the air introduction chamber 43 into the main ink storage chamber 44 in accordance with the amount of consumed ink. The ink level in the ink storage chamber 44 is lowered (see FIG. 4A). When the ink is further consumed and the ink in the main ink storage chamber 44 runs out, the ink in the sub ink storage chamber 45 is supplied to the print head 3. At this time, the pressure in the sub ink storage chamber 45 is reduced, but air from the air introduction chamber 43 through the main ink storage chamber 44 is introduced into the sub ink storage chamber 45 through the ink communication port 49 and the sub ink storage chamber 45 is stored. The pressure in the chamber 45 is reduced and the ink level is lowered (see FIG. 4B).

  Therefore, the ink cartridge 2 first consumes the ink in the main ink storage chamber 44, and after all the ink in the main ink storage chamber 44 is consumed, the ink in the sub ink storage chamber 45 is consumed. It is configured. Therefore, the presence or absence of ink in the entire ink cartridge 2 can be known by detecting the presence or absence of ink in the sub ink storage chamber 45 by the ink sensor 19.

  Further, a first fitting recess 55 is formed in the bottom wall 46 of the ink cartridge 2. The first fitting recess 55 is a member for positioning the ink cartridge 2 by fitting with the fitting protrusion 24 (see FIG. 2) protruding from the mounting portion 4a of the head unit 4. 46 is recessed at the end opposite to the ink supply port 50 (left side in FIG. 3A). Further, as shown in FIG. 3C, the first fitting recess 55 is disposed substantially at the center of the ink cartridge 2 in the thickness direction (perpendicular to the paper surface of FIG. 3A). Here, an annular groove is formed in the outer periphery of the ink supply port 50 of the ink cartridge 2 and the ink supply passage 22 of the head unit 4, and an O-ring disposed in the annular groove. 23 (see FIG. 2). With this connection alone, when the carriage 5 moves, the ink cartridge 2 rotates around the ink supply port 50 (O-ring 23) due to inertia and cannot be positioned accurately. Therefore, as described above, the ink cartridge 2 is rotated by providing the bottom wall 46 with the first fitting recess 55 that can be fitted with the fitting projection 24 of the head unit 4 (see FIG. 3C). The ink cartridge 2 can be positioned while preventing the ink cartridge 2 from being removed. As a result, the ink cartridge 2 can be accurately fixed to the head unit 4.

  On the other hand, a second fitting recess 57 is provided in the upper wall 56 of the ink cartridge 2. The second fitting recess 57 is a portion that fits with a locking claw 29 (see FIG. 2) formed on the fixing arm 21 of the head unit 4 when the ink cartridge 2 is fixed to the head unit 4. The second fitting recess 57 is for preventing the ink cartridge 2 from being laterally shifted in the width direction (the left-right direction in FIG. 3A) and preventing the ink cartridge 2 from floating. Corresponding to approximately the center in the width direction of the cartridge 2 (left and right direction in FIG. 3A), that is, approximately the center in the width direction of the ink supply port 50 and the first fitting recess 55 formed in the bottom wall 46. It is recessed at the position to be. Therefore, the ink cartridge 2 is supported in a well-balanced manner by the three points of the second fitting recess 57, the ink supply port 50, and the first fitting recess 55. Therefore, it is possible to prevent the ink cartridge 2 from being lifted and rattling when tilted to one side, so that the ink cartridge 2 can be firmly fixed to the head unit 4 in a stable state.

  In addition, a pair of side wall plates 58 and 58 are provided on both sides of the second fitting recess 57 (on the front side and the back side in FIG. 3A) to face each other with a predetermined interval therebetween. The side wall plates 58 and 58 are for preventing the lateral displacement of the ink cartridge 2, and the opposing surfaces thereof are opposed to face the thickness direction of the ink cartridge 2 (the direction perpendicular to the paper surface in FIG. 3A). ing. Further, the interval between the facing surfaces is formed to have a width substantially equal to the locking claw 29 (see FIG. 2) of the fixed arm 21 fitted in the second fitting recess 57. Therefore, when the locking claw 29 of the fixed arm 21 is fitted into the second fitting recess 57, the side wall plates 58 and 58 cause the ink cartridge 2 to be in its thickness direction (perpendicular to the paper surface in FIG. 3A). It is prevented from moving to (horizontal misalignment).

  Here, as described above, the head unit 4 performs printing while reciprocating in the thickness direction of the ink cartridge 2 (perpendicular to the paper surface in FIG. 3A) (see FIG. 1). The head unit 4 reciprocates while repeating rapid acceleration / deceleration in order to improve the printing speed. Therefore, when the ink cartridge 2 is laterally displaced in the moving direction of the head unit 4, the head unit 4 itself vibrates due to the lateral displacement, which adversely affects the print quality. However, since the side wall plates 58 and 58 prevent the ink cartridge 2 from shifting laterally (rattle) in the moving direction of the head unit 4, the head unit 4 can smoothly reciprocate without vibration. As a result, good print quality can be obtained.

  A pair of ribs 61 and 61 are provided on the side of the ink cartridge 2 (on the left side in FIG. 2), and the ribs 61 and 61 are spaced apart from each other by a predetermined interval in the same manner as the side walls 58 and 58 described above. They are formed to face each other. On the other hand, the head unit 4 is provided with a locking projection 4h (see FIG. 2) at a position corresponding to the ribs 61, 61, and when the ink cartridge 2 is mounted on the head unit 4, The engaging projection 4h is fitted between the opposing surfaces of the ribs 61 (see FIG. 2). Therefore, the ink cartridge 2 is prevented from being laterally shifted (rattle) during printing by the pair of ribs 61 and 61 as well.

  The upper wall 56 is disposed on the first upper wall 56a disposed on one side of the second fitting recess 57 (left side of FIG. 3A) and on the other side (right side of FIG. 3A). The first upper wall 56a is formed such that the height from the bottom wall 46 is lower than that of the second upper wall 56b. On the other hand, a handle portion 59 is disposed on the second upper wall 56b on the side opposite to the first upper wall 56a. The handle portion 59 is a portion for the operator to grip when the ink cartridge 2 is mounted on the head unit 4 and is formed so as to protrude upward (upper side in FIG. 3A) so as to be easily gripped. ing. Therefore, when only one ink cartridge 2 is removed from the head unit 4 when replacing the ink cartridge 2 or the like, it is possible to remove the other adjacent ink cartridges 2 without obstructing by gripping the handle portion 59. . On the other hand, when the ink cartridge 2 is mounted, it can be easily mounted in a narrow space by holding the ink cartridge 2 by holding the handle portion 59.

  Further, when the ink cartridge 2 is attached to the head unit 4, the ink cartridge 2 is inserted into a predetermined portion of the head unit 4 from the first upper wall 56a side. As described above, the height from the bottom wall 46 is low. Therefore, it is possible to prevent the first upper wall 56a and the vicinity of the shaft support portion (on the side of the stopper portion 27) of the fixed arm 21 flipped upward from interfering with each other, so that the ink cartridge 2 can be easily caught without being caught on the head unit 4. (See FIG. 2).

  The reason why the entire upper wall 56 is not thin is to maintain the rigidity that can withstand the pressing of the pressing portion 28.

  In addition, the 1st convex part 62 is protrudingly provided by the side (right side of FIG. 3) of the 1st upper wall 56a upwards (upper side of FIG. 3), and the above-mentioned 2nd fitting recessed part 57 is the One side wall is formed by the first convex portion 62. Therefore, when the locking claw 29 of the fixed arm 21 is fitted into the second fitting recess 57, the ink cartridge 2 is moved in the width direction (rightward in FIG. 3A) by the first projection 62. It is possible to prevent (horizontal misalignment) and to prevent the ink cartridge 2 from being lifted.

  Next, the principle of ink presence / absence detection will be described with reference to FIGS. 4A and 4B are side views of the ink cartridge 2 and the ink sensor 19, and a part of the ink cartridge 2 is viewed in cross section. 4A and 4B schematically show the head unit 4 and the ink sensor 19 with the mounting members and the like omitted.

  When there is sufficient ink 71 in the ink cartridge 2, as shown in FIG. 4A, the infrared light emitted from the infrared light emitting element 19 a of the ink sensor 19 is (optical path X), and the ink cartridge 2 Since the refractive index of this material and the refractive index of the ink 71 are very close, the ink cartridge 2 travels through the ink 71 while passing through the ink 71. Then, the light reaches the reflecting member 53 disposed in the sub ink storage chamber 45. The infrared light that has reached the reflecting member 53 is reflected at the interface between the inner surface of the reflecting member 53 and the air 72 (optical path Y) because the refractive index of the material of the reflecting member 53 and the refractive index of the air 72 are different.

  Here, since the inclined portion 51a of the ink cartridge 2 is inclined at approximately 20 degrees with respect to the reflecting member 53, the incident angle of the infrared light reaching the reflecting member 53 is different from the incident angle to the inclined portion 51a. Is. Therefore, the reflected light (optical path Y) reflected by the reflecting member 53 is reflected at an angle different from the incident light. Therefore, the reflected light (infrared light) does not go to the infrared light receiving element 19b of the ink sensor 19, and the amount of reflected light going to the infrared light receiving element 19b is small.

  On the other hand, when the ink 71 does not exist in the sub ink storage chamber 45 of the ink cartridge 2, the red light emitted from the infrared light emitting element 19a of the ink sensor 19 as shown in FIG. The external light (optical path X) is reflected at the interface between the inner surface of the outer wall of the sub ink storage chamber 45 and the air (optical path Y) because the refractive index of the material of the ink cartridge 2 is different from the refractive index of air. Therefore, the amount of reflected light from the ink cartridge 2 toward the infrared light receiving element 19b of the ink sensor 19 is large.

  Thus, since the amount of reflected light (optical path Y) reflected from within the ink cartridge 2 changes depending on the presence or absence of ink, the difference in the amount of light is detected using the infrared light receiving element 19b of the ink sensor 19. By doing so, the presence or absence of ink stored in the ink cartridge 2 can be detected.

  Further, since the inclined portion 51 a and the reflection member 53 are disposed above the sub ink storage chamber 45, the ink 71 no longer exists above the sub ink storage chamber 45, that is, the ink in the ink cartridge 2. It is possible to determine in advance that there is no ink before all 71 exists.

  In the present embodiment, the inclination of the inclined portion 51a is approximately 20 degrees, but is not limited to this angle, and may be in the range of approximately 15 degrees to approximately 25 degrees. That is, by setting the angle to approximately 15 degrees or more, it is possible to suppress the reflected light from the reflecting member 53 from returning to the infrared light receiving element 19b. By setting the angle to approximately 25 degrees or less, the ink is always stored in the inclined portion 51a. Can be suppressed.

  Next, FIG. 5 shows the reason why the ink sensor 19 is arranged obliquely at an angle of about 10 degrees in the horizontal direction with respect to the inclined portion 51a (see FIG. 3) of the ink cartridge 2 which is the surface irradiated with infrared light. The description will be given with reference. FIG. 5 is a top view showing the ink cartridge 2 and the ink sensor 19. The ink cartridges 2a to 2d mounted on the head unit 4 are reciprocally conveyed in the direction of arrow W.

  First, when the ink sensor 19 is disposed perpendicular to the inclined portion 51a (see FIG. 5A), the light (optical path X) emitted from the infrared light emitting element 19a is a light transmissive member. Is transmitted through the inclined portion 51a. However, incident light (optical path X) that should pass through the inclined portion 51a may be reflected by the outer surface of the inclined portion 51a due to fine irregularities on the outer surface (on the opposite side of the ink) of the inclined portion 51a. . When the reflected light (optical path Y) is received by the infrared light receiving element 19b, it is determined that the ink 71 does not exist even though the ink 71 exists in the sub ink storage chamber 45. There is a fear that it has a negative effect on the detection accuracy of the presence or absence of the original ink.

  On the other hand, when the ink sensor 19 is disposed at an angle larger than approximately 10 degrees with respect to the inclined portion 51a (see FIG. 5B), for example, even if the ink cartridge 2b is not present, the infrared sensor The light (optical path X) emitted from the light emitting element 19a may be reflected by the adjacent ink cartridge 2c. When the reflected light (optical path Y) is received by the infrared light receiving element 19b, it may be determined that the ink cartridge 2b is present even though the ink cartridge 2b is not present. In some cases, the presence or absence of the cartridge 2b cannot be detected.

  Therefore, when the ink sensor 19 is disposed at approximately 10 degrees with respect to the inclined portion 51a (see FIG. 5C), since the infrared light receiving element 19b is inclined, the outer side of the inclined portion 51a ( It is possible to suppress the reception of light reflected by the surface on the side opposite to the ink (see the optical path Y in FIG. 5A). Therefore, when ink is present, the light transmitted through the inclined portion 51a is not received as described with reference to FIG. 4. On the other hand, when there is no ink, the inside of the inclined portion 51a (on the sub ink storage chamber 45 side). Reflected light (optical path Y) from the interface between air and air is received by the infrared light receiving element 19b. Therefore, it is possible to accurately determine the presence or absence of ink based on the difference in the amount of light. Even if the ink cartridge 2c is not provided, the light emitted from the infrared light emitting element 19a is not emitted to the adjacent ink cartridge 2d (see the optical path X1). It can be judged.

  In the present embodiment, the inclination is set to approximately 10 degrees, but this is caused by various factors such as the size of the ink cartridge 2, the gap between the ink cartridges 2, and the gap between the ink cartridge 2 and the ink sensor 19. Since the angle is determined by the above, it is only necessary to have an inclination, and the angle is not limited to this.

  FIG. 6 is a block diagram showing an outline of an electric circuit configuration of the color inkjet printer 1. The control device for controlling the color inkjet printer 1 includes a main body side control board 100 and a carriage board 120, and the main body side control board 100 has a one-chip microcomputer (CPU) 91 and its CPU 91. ROM 92 that stores various control programs and fixed value data executed by the RAM, RAM 93 that is a memory for temporarily storing various data, and the like, EEPROM 94 that is a rewritable nonvolatile memory, and image memory 95 A gate array 96 and the like are mounted.

  The CPU 91, which is an arithmetic unit, executes control for detecting the presence / absence of ink and the presence / absence of an ink cartridge according to a control program stored in the ROM 92 in advance. Further, a print timing signal and a reset signal are generated, and each signal is transferred to a gate array 96 described later. The CPU 91 includes an operation panel 107 for a user to give a printing instruction, a motor drive circuit 102 for driving a carriage motor (CR motor) 101 for operating the carriage 5, and a conveyance motor (for conveying the recording medium P). A motor drive circuit 104 for operating the (LF motor) 103, a paper sensor 105 for detecting the leading end of the recording medium (printing paper) P, an origin sensor 106 for detecting the origin position of the carriage 5, an ink sensor 19 and the like are connected. Yes. The operation of each connected device is controlled by the CPU 91.

  As a part of the control program, the ROM 92 measures the positional relationship (relative position) between the ink sensor 19 and the irradiated surface of the ink cartridge 2, that is, the detected position of the ink cartridge 2, and deviates from the theoretical value ( Calibration data input processing (see FIG. 7) for inputting the correction value) as calibration data, ink detection processing (see FIG. 8) for detecting the presence or absence of ink in the ink cartridge 2, and whether or not the ink cartridge is mounted. A program for ink cartridge detection processing (see FIG. 10) for detection is stored. Details of each program will be described later. Further, as fixed value data, a first threshold value for verifying the absence of ink at the detected reflected light level, a second threshold value for verifying that the ink cartridge is not installed at the detected reflected light level, and an ink level An empty threshold value, which is the number of ink ejections until the (ink remaining amount in the ink cartridge 2) becomes empty from near empty, is stored.

The RAM 93 includes a maintenance mode flag 93a. Maintenance mode flag 93a is the operation mode of the color ink Jefferies Tsu Topurinta 1 is a flag indicating that is set to the maintenance mode for adjusting the color ink jet printer 1. The maintenance mode is set by operating a mode switch 107a provided on the operation panel 107. By selecting this maintenance mode, the maintenance mode flag 93a is turned on. The maintenance mode flag 93a turned on is turned off when a command indicating the end of adjustment of the color inkjet printer 1 is input. The calibration data input process described above is a program that can be executed when the maintenance mode flag 93a is turned on, and the correction value can be stored only when the flag 93a is turned on.

  The EEPROM 94 includes a calibration data memory 94a, first to fourth counters 94b to 94e, and first to fourth near empty flags 94f to 94i. The calibration data memory 94a is a memory for storing the correction value detected by the calibration data input process, that is, the positional deviation from the original detection position of the ink cartridge 2 as calibration data.

  As described above, in the color inkjet printer 1 of the present embodiment, the ink sensor 19 is installed at an angle of approximately 10 degrees with respect to the irradiated surface of the ink cartridge 2. However, due to the mounting angle error that occurs when the sensor 19 is mounted, the angle often does not become approximately 10 degrees. In such a case, the relative position between the ink sensor 19 and the ink cartridge 2 is different from the original position. That is, the ink cartridge 2 is displaced from the original detection position of the ink cartridge 2, and the ink sensor 19 cannot accurately detect the ink cartridge 2 at the original detection position. For this reason, a calibration data input process executed before shipment detects a deviation between the original detection position and the actual detection position, and the deviation amount is used as a correction value (in advance before shipment). 94a is written.

When detecting the presence / absence of the ink cartridge 2 (inspection of ink cartridge not installed) and the presence / absence of ink (inspection of no ink), the correction value stored in the calibration data memory 94a is referred to. Based on this, the detection position (position of the carriage 5) for detecting the amount of reflected light is adjusted. Thereby, even if the positional relationship between the ink sensor 19 and the irradiated surface of the ink cartridge 2 is deviated from the original position, the presence / absence of the ink cartridge 2 and the presence / absence of ink can be accurately detected.

  The first to fourth counters 94b to 94e are memories for counting up the number of ink ejections (ejections) from the print head 3, and are updated by "1" every time the number of ink ejections is "1". A predetermined amount of ink is initially injected into the ink cartridge 2, and the approximate maximum number of ejections is determined from the amount of ink. For this reason, it is possible to know the approximate ink consumption by counting the number of ink ejections.

  Since the color ink jet printer 1 is provided with four ink cartridges 2 for storing inks of black, cyan, magenta, and yellow, respectively, four counters (first to first counters) corresponding to each ink cartridge 2 are provided. Fourth counters 94b to 94e) are provided, and the number of ink ejections counted for each ink is written in the corresponding first to fourth counters 94b to 94e. The count values stored in the first to fourth counters 94b to 94e are referred to by the ink detection process, and every time the count value reaches a predetermined number, the actual ink level (the ink in the ink cartridge 2). In order to investigate the remaining amount), ink detection by the ink sensor 19 (ink detection process, see FIG. 8) is executed.

  A predetermined amount of ink is ejected from the ink cartridge 2 not only during printing but also in a purge process for sucking out bubbles in the ink cartridge 2 and a flushing process for solving clogging of nozzles. Regarding the ink consumed in such processing, since it is known how many times the number of ejections during printing is known, the corresponding count number is added to the previously stored count value to correspond. The count values of the first to fourth counters 94b to 94e are updated.

  The first to fourth near empty flags 94f to 94i are provided one by one corresponding to the four ink cartridges 2 for storing the respective colors of black, cyan, magenta, and yellow, and the flags 94f to 94i. ON indicates ink near empty. Here, the near empty indicates the limit of ink detection by the ink sensor 19 and indicates a state where the ink sensor 19 detects that there is no ink.

  As described with reference to FIGS. 3 and 4, the ink filled in the initial state is consumed from the main ink storage chamber 44, and when the main ink storage chamber 44 becomes empty, the ink in the sub ink storage chamber 45 is consumed. When the ink liquid level in the sub ink storage chamber 45 falls below the lower portion of the reflecting member 53, the light emitted from the infrared light emitting element 19a of the ink sensor 19 is directed by the prism 52 toward the infrared light receiving element 19b of the ink sensor 19. Reflected to (optical path Y). As a result, the amount of reflected light detected by the infrared light receiving element 19b of the ink sensor 19 greatly changes (increases). Since the detected amount of reflected light is input as a signal to the CPU 91, the change is recognized by the CPU 91 as near empty, and the corresponding near empty flags 94f to 94i are turned on.

  When the first to fourth near empty flags 94f to 94i are turned on (detected as no ink by the ink sensor 19), the ink in the ink cartridge 2 is not empty (empty). Printing can be continued until this state (the number of ink ejections reaches the empty threshold).

In this embodiment, when the first to fourth near empty flags 94f to 94i are turned on in order to accurately detect ink empty, the count values stored in the corresponding first to fourth counters 94b to 94e. 0 is cleared, and 0 to the empty threshold is counted up to improve the detection accuracy of ink empty. The first to fourth near empty flags 94f to 94i that are turned on are turned off when the ink level of the corresponding ink cartridge 2 is detected, for example, by replacement or the like (see FIG. 10). .

  The CPU 91, the ROM 92, the RAM 93, the EEPROM 94, and the gate array 96 are connected via an address bus 98 and a data bus 99.

  The gate array 96, in accordance with the print timing signal transferred from the CPU 91, based on the image data stored in the image memory 95, print data (drive signal) for printing the image data on a recording medium, and the print Outputs a transfer clock CLK synchronized with data, a latch signal, a parameter signal for generating a basic print waveform signal, and an ejection timing signal JET output at a constant cycle, and these signals are mounted by the head driver. Transfer to the carriage substrate 120 side. The gate array 96 stores image data transferred from an external device such as a computer via the Centro interface 97 in the image memory 95. The gate array 96 generates a Centro data reception interrupt signal based on the Centro data transferred from the host computer or the like via the Centro interface 97, and transfers the signal to the CPU 91. Each signal communicated between the gate array 96 and the carriage substrate 120 is transferred via a harness cable that connects the two.

  The ink sensor 19 includes an infrared light emitting element 19a and an infrared light receiving element 19b, and irradiates infrared light from the infrared light emitting element 19a to the ink cartridge 2 (optical path X in FIG. 4), and its reflected light. (Optical path Y in FIG. 4) is detected by an infrared light receiving element 19b which is a photosensor. The reflected light received by the infrared light receiving element 19b is photoelectrically converted by the infrared light receiving element 19b and detected as an electric signal corresponding to the received reflected light amount. Since the detected signal is an analog signal, it is converted into a digital signal by the A / D converter 19c connected to the infrared light receiving element 19b and then input to the CPU 91. The amount of reflected light detected by the ink sensor 19 is compared with the first or second threshold value in the ink detection process or the ink cartridge detection process. Thereby, it is possible to know the presence or absence of ink in the ink cartridge 2 and the presence or absence of the ink cartridge. The A / D converter 19c converts the analog signal into a digital signal through steps such as sampling, quantization, and binarization.

  The carriage substrate 120 is a substrate for driving the print head 3 by a mounted head driver (drive circuit). The print head 3 and the head driver are connected by a flexible wiring board in which a copper foil wiring pattern is formed on a polyimide film having a thickness of 50 to 150 μm. This head driver is controlled via a gate array 96 mounted on the main body side control board 100, and applies a drive pulse having a waveform suitable for the recording mode to each drive element. Thereby, a predetermined amount of ink is ejected.

  Next, each process executed by the color inkjet printer 1 configured as described above will be described with reference to the flowcharts shown in FIGS.

  FIG. 7 is a flowchart of calibration data input processing that is one of the control programs. This calibration data input process is a process for detecting a positional deviation of the detection position of the ink cartridge 2 and storing the deviation amount as a correction value in the calibration data memory 94a before shipment.

  Since the calibration data input process can be executed only when the operation mode of the color inkjet printer 1 is set to the maintenance mode for performing the adjustment, the calibration data input process starts with the maintenance mode. It is confirmed whether or not the flag 93a is turned on (S1). If it is not turned on (S1: No), the calibration data input process is terminated. On the other hand, if the maintenance mode flag 93a is turned on (S1: Yes), the origin sensor 106 confirms that the carriage 5 is at the origin, and then drives the CR motor 101 to move the carriage 5 from the origin by a predetermined distance. As a result, the carriage 5 is moved to the home position (S2). Next, the infrared light emitting element 19a is turned on with a predetermined amount of light (S3), and the carriage 5 is moved toward the ink sensor 19 at a low speed (S4). When a predetermined detection position is reached (when the carriage 5 moves by a predetermined distance from the origin), detection of the reflected light amount by the ink sensor 19 is started, and the reflected light level (reflected light amount) reflected by the ink cartridge 2 is Light is received by the infrared light receiving element 19b and taken into the CPU 91 via the A / D converter 19c (S5). The detection of the reflected light level is performed not only on the original detection position of the ink cartridge 2 but also over a range wider than the width of the carriage 5, and the reflected light level is detected by analog data (see FIG. 11).

  Next, for the reflected light level that has been taken in, a change position where the detection signal indicating the reference ink cartridge 2 changes from the level without ink cartridge to the level with ink cartridge is detected (S6). At a position where the ink cartridge 2 is not present (not mounted), reflection of the irradiated infrared light is small, and therefore, the detected reflected light level at the level without the ink cartridge is small. On the other hand, at the position where the ink cartridge 2 is present (attached), the reflected infrared light is highly reflected, and the detected reflected light level with the ink cartridge is also large. That is, this change position where the reflected light level changes from the ink cartridge absent level to the ink cartridge equipped level is the detection position of the ink cartridge 2 (see FIG. 11).

  Then, the shift (original detection position) between the change position (theoretical value) from the theoretically absent ink cartridge level to be obtained to the ink cartridge presence level and the change position (actual value) detected in the process of S6. And the actual detection position) are calculated as the carriage movement distance α, and the deviation is stored as a correction value in the calibration data memory 94a (S7). Here, the original detection position (theoretical value) is stored as a movement distance from the origin of the carriage 5. Therefore, the actual detection position is the theoretical movement distance ± α, and this ± α distance is the correction value.

  The correction value stored in the calibration data memory 94a in the calibration data input process is used in the calibration process (S15) executed in the ink detection process and the ink cartridge detection process. As a result, the detection position when detecting the reflected light from the ink cartridge 2 can be corrected, and the reflected light level can be accurately detected.

  In this embodiment, the actual detection position is compared with the theoretical detection position in the reference ink cartridge 2 in the process of S6. This reference ink cartridge 2 is composed of four inks mounted on the carriage 5. The head ink cartridge 2 of the cartridge 2, that is, the ink cartridge 2 that is detected first (reached the detection position) is used.

  FIG. 8 is a flowchart illustrating an ink detection process for detecting ink, that is, detecting the presence or absence of the ink 71 in the ink cartridge 2. The ink detection process is a process that is repeatedly executed at a predetermined timing in order to detect ink consumption during the operation of the print head 3.

  In this ink detection process, first, what is being executed in the color inkjet printer 1 is checked (S11). If the process being executed is printing (S11: printing), a one-pass printing process for printing for one pass is executed (S12). In this one-pass printing process (S11), in order to calculate consumed ink, the number of ink ejections from each ink cartridge 2 is counted and stored in the corresponding first to fourth counters 94b to 94e. Count up the count value.

  Next, it is confirmed whether or not the first to fourth near empty flags 94f to 94i of the ink cartridge 2 are turned on (S13). As a result of confirmation, if the first to fourth near empty flags 94f to 94i are off (S13: No), the ink corresponding to the turned off (flag off) first to fourth near empty flags 94f to 94i. It is checked whether or not the count value of the cartridge 2 is greater than a predetermined number d (for example, 100) (S14). In this ink detection process, the presence or absence of ink is detected by the ink sensor 19 every time the number of ink ejection passes a predetermined number d.

  Here, if the count value is equal to or greater than a predetermined number d (for example, 100) (S14; Yes), correction of the detection position and reflected light level (in order to detect the presence or absence of ink (no ink)) by the ink sensor 19 are performed. A calibration process for capturing the reflected light amount is executed (S15). After the execution of the calibration process (S15), it is determined whether the captured reflected light level is equal to or higher than the first threshold value (S16). The first threshold value is a reflected light level for identifying whether ink is present or absent.

  As a result of the determination in the process of S16, if the captured reflected light level is equal to or higher than the first threshold value (S16: Yes), the ink liquid level in the sub ink storage chamber 45 is below the lower part of the reflecting member 53. This indicates that the ink level (remaining amount of ink in the ink cartridge 2) is near empty (tested to be out of ink). Therefore, the first to fourth near empty flags 94f to 94i of the corresponding ink cartridge 2 are turned on (S17), and the corresponding count value (the count value stored in the corresponding first to fourth counters 94b to 94e). ) Is set to 0 (S18). Thereafter, other processes are executed (S19), and the ink detection process is terminated.

  As a result of checking in the process of S11, if the process being executed is purge or flushing (S11: purge, flushing), purge and flushing processes are executed (S22). This purge and flushing process (S22) is a process of performing a purge process for discharging ink to suck out bubbles in the ink cartridge 2 or a flushing process for discharging ink to eliminate clogging of the print head 3. It is. In this purge and flushing process (S22), a predetermined amount of ink is discharged, but it is known how many times the ink amount corresponds to the number of ejections during printing, and this value is stored in the ROM 92 in advance. Stored as a fixed value. Therefore, the ink consumed by the number of ejections is counted, and the count values stored in the corresponding first to fourth counters 94b to 94e are counted up by the count. After execution of the purge and flushing process (S22), the process proceeds to S13.

  On the other hand, if the first to fourth near empty flags 94f to 94i of the ink cartridge 2 are turned on (S13: Yes) as a result of checking in the process of S13, the first to fourth turned on (flag on). It is checked whether or not the count value of the ink cartridge 2 corresponding to the near empty flags 94f to 94i is equal to or greater than the empty threshold (S20). Since the ink level of the ink cartridge 2 corresponding to the flag-on first to fourth near empty flags 94f to 94i exceeds the ink detection limit by the ink sensor 19, the number of ink ejections after the near empty is counted. By doing so, ink empty is detected.

  Here, if the confirmed count value is less than the empty threshold value (S20: No), the remaining amount of ink that can be printed still remains, so that the process shifts to S19 and each process (S19). ), The ink detection process is terminated. If the count value of the ink cartridge 2 corresponding to the turned on first to fourth near empty flags 94f to 94i is equal to or greater than the empty threshold value (S20: Yes) as a result of checking in the process of S20, the ink Ink empty processing for displaying empty is executed (S21). After executing the process of S21, the process proceeds to the process of S19, and after executing each process (S19) such as temporarily storing data that could not be printed, this ink detection process is terminated.

  Further, as a result of checking in the process of S14, if there is no count value equal to or larger than a predetermined number d (for example, 100) (S14; No), the process is shifted to the process of S19 and each process (S19) is performed. After execution, the ink detection process is terminated.

  Further, as a result of checking in the process of S16, if the captured reflected light level is less than the first threshold (S16: No), the ink level is not near empty, so the process of S17 is skipped and the process is performed. The process proceeds to S18.

  When the ink cartridge 2 is exchanged (detached) (ink cartridge detection process), the count values of the first to fourth counters 94b to 94e corresponding to the ink cartridge 2 are set to 0, and the number of ink discharges is set. Although the count-up is started, the ink filling amount of the replaced ink cartridge 2 varies due to, for example, mounting of used products or manufacturing variations. Further, in consideration of variations in the amount of ink discharged from the print head 3 of each color inkjet printer 1, the count values until reaching near empty are not necessarily the same. For this reason, if the count is continuously increased from the initial state to the ink empty, it becomes difficult to determine the ink empty with a certain threshold value (predetermined count value), and the detection is performed with the predetermined count value. Ink emptying tends to be inaccurate. However, since the remaining amount of ink in the ink cartridge 2 is considered to be substantially the same when near empty is detected, the number of ink ejections (count value) required to consume this remaining amount of ink is also the same. Conceivable. Therefore, if the predetermined threshold value in the vicinity of the number of ejections is set as an empty threshold value, the time point when the near empty state is detected (near empty flag on) is set to 0 count, and the count up to the empty threshold value is counted up, the ink empty is accurately determined Can be detected.

  FIG. 9 is a flowchart of the calibration process (S15) executed in the ink detection process of FIG. In this calibration process (S15), the detection position of the ink cartridge 2 is corrected based on the correction value stored in the calibration data memory 94a in order to detect the presence or absence of ink, and the reflected light is reflected at the corrected detection position. This is processing for taking in the level (the amount of reflected light).

  In this calibration process (S15), first, the carriage 5 is moved to the home position (S31). Then, the carriage 5 is moved from the home position toward the ink sensor 19 (S32), and it is confirmed whether or not the carriage 5 has reached the position where the correction value is added to the original detection position of one ink cartridge 2. (S33). When the carriage 5 has reached the detection position in which the correction value is added (S33: Yes), the infrared light emitting element 19a is turned on with a predetermined amount of light, and the reflected light level is detected (S34). Next, it is confirmed whether or not the reflected light levels are detected for four (all) ink cartridges 2 (S35). If all the reflected light levels are detected (S35: Yes), this calibration is performed. The process (S15) ends.

  On the other hand, if the carriage 5 has not reached the detection position with the correction value added as a result of the confirmation in S33 (S33: No), the process proceeds to S32, and the carriage 5 is moved in the direction of the ink sensor 19. Moving. If the reflected light levels of all the ink cartridges 2 are not detected as a result of the confirmation in S35 (S35: No), the process proceeds to S32, and the reflected light levels of all the ink cartridges 2 are detected. This calibration process (S15) is executed until is detected.

  In the calibration process (S15), the amount of reflected light (reflected light level) reflected from a predetermined position (one point) of each ink cartridge 2 is detected by the ink sensor 19. That is, the reflected light level is pinpoint data detected at the pinpoint. For this reason, the amount of data to be processed can be reduced, and data processing can be performed efficiently. Further, since the presence / absence of ink is detected during the printing operation, the carriage 5 is moved at a high speed, but each ink cartridge 2 is accurately detected based on the correction value stored in the calibration data memory 94a. It is conveyed to. For this reason, the reflected light level can be accurately detected (even point data).

  FIG. 10 is a flowchart illustrating the ink cartridge detection process. This ink cartridge detection process is a process for detecting whether or not an ink cartridge is mounted. Therefore, although it is performed at the timing when the ink cartridge 2 is replaced, the sensor provided on the cover of the color inkjet printer 1 recognizes that the cover is opened and closed and recognizes it as ink cartridge replacement.

  In this ink cartridge detection process, first, after the cover is opened, it is confirmed whether or not it is closed (S41). When it is detected that the cover is closed, the calibration process (S15) described above is executed, and the reflected light of the ink cartridge 2 is detected at a predetermined detection position. Thereafter, whether or not the reflected light level of the ink cartridge 2 in which the first to fourth near empty flags 94f to 94i are turned on is lower than the first threshold value, that is, whether or not the ink is filled. (S43), and as a result, if the reflected light level is less than the first threshold value (S43: Yes), this means that the ink cartridge 2 having a small remaining amount of ink has been replaced. The near empty flags 94f to 94i of the ink cartridge 2 are turned off (S44), and the count values of the counters 94b to 94e of the corresponding ink cartridge 2 are cleared (S45). Thereafter, it is confirmed whether four reflected light levels that are equal to or higher than the second threshold value (threshold value for verifying that the ink cartridge is not installed) have been detected (S46). When the reflected light level below is detected (S46: No), it is determined that the ink cartridge has not been installed, and after executing an ink cartridge no error process for notifying that the ink cartridge has not been installed (S47), The ink cartridge detection process ends.

  If the cover is not closed as a result of checking in the process of S41 (S41: No), the ink cartridge detection process is terminated. Further, as a result of checking in the process of S43, if the reflected light level is equal to or higher than the first threshold (S43: No), the process proceeds to S46. On the other hand, as a result of checking in the process of S46, if four reflected light levels exceeding the second threshold are detected (S46: Yes), it means that all the ink cartridges 2 are installed. The cartridge detection process ends.

  FIG. 11 is a diagram schematically showing a change in the reflected light level of the ink cartridge 2. The amount of reflected light is shown on the vertical axis, and the amount of reflected light increases as it goes up on the vertical axis. Further, a first threshold value for determining the absence of ink is indicated by a broken line, a value equal to or higher than the first threshold value is a reflected light level indicating no ink (near empty), and a value less than the first threshold value is ink. The reflected light level indicating existence is present. Further, below this first threshold value, a second threshold value for verifying that the ink cartridge is not installed is indicated by a broken line.

  FIG. 11A is a diagram showing the theoretical reflected light level detected at the original detection position. As shown in the figure, the presence or absence of ink can be detected by examining the obtained reflected light level (signal waveform) with the first threshold value, and the same reflected light level is smaller than the first threshold value. The presence or absence of the ink cartridge 2 can be detected by testing with the second threshold value. This is because a clear difference in reflected light amount can be obtained with and without ink and with and without an ink cartridge.

  FIG. 11B is a diagram showing a signal waveform of the reflected light level detected in the calibration data input process. FIG. 11B shows the signal waveform of the reflected light level when the mounting angle of the ink sensor 19 is shifted in the direction perpendicular to the irradiated surface of the ink cartridge 2, and the actual detection position is the original detection position. It is shown that it is in front of the detection position. The ink cartridge 2a in which the first black ink is stored is a reference ink cartridge in the calibration data input process, and the deviation amount α from the original detection position in the black ink cartridge 2a becomes a correction value. Yes.

  Next, a second embodiment will be described with reference to FIG. The ink cartridge 2 of the first embodiment is configured to change the optical path of infrared light by the reflecting member 53, whereas the ink cartridge 130 of the second embodiment absorbs infrared light. An absorbing member 131 is provided. In addition, the same code | symbol is attached | subjected to the part same as above-described 1st Example, and the description is abbreviate | omitted.

  12A and 12B are side views of the ink cartridge 130 and the ink sensor 19, and a part of the ink cartridge 130 is viewed in cross section. 12A and 12B schematically show the head unit 4 and the ink sensor 19 with the mounting members and the like omitted.

  As in the first embodiment, the ink cartridge 130 is formed with a prism 52 on the inner surface side (ink interface side) of the inclined portion 51a irradiated with infrared light. A main ink storage chamber 44 in which 48 is stored and a sub ink storage chamber 45 in which an infrared light absorbing member 131 described later is stored are partitioned by a partition wall 42. The infrared light absorbing member 131 is a member for absorbing infrared light irradiated from the infrared light emitting element 19a of the ink sensor 19 and transmitted into the ink cartridge 130, and is opposed to the prism 52 with a predetermined interval. In the state, it is disposed in the sub ink storage chamber 45.

  Next, a detection method for detecting the presence or absence of the ink 71 in the ink cartridge 130 in which the infrared light absorbing member 131 is disposed will be described. As in the first embodiment, the ink sensor 19 emits infrared light from the infrared light emitting element 19a toward the inclined portion 51a of the ink cartridge 130. Then, when the infrared light receiving element 19b receives the reflected light, and the amount of the reflected light is equal to or less than a certain value, it is determined that there is ink in the ink cartridge 130 (in the case of FIG. 12A), If the amount of reflected light is greater than a certain value, it is determined that there is no ink in the ink cartridge 130 (in the case of FIG. 12B).

  Specifically, when the sub ink storage chamber 45 is filled with the ink 71, the infrared light emitted from the infrared light emitting element 19a is (optical path X) as shown in FIG. Since the refractive index of the material of the inclined portion 51a (prism 52) and the refractive index of the ink 71 are very close, the ink cartridge 130 travels through the ink 71. Then, it reaches the infrared light absorbing member 131 disposed in the sub ink storage chamber 45, and the infrared light is absorbed by the infrared light absorbing member 131. Accordingly, the amount of reflected light received by the infrared light receiving element 19b of the ink sensor 19 is small (below a certain value).

  Here, the inclined portion 51a is inclined at approximately 20 degrees with respect to the infrared light absorbing member 131 as in the first embodiment. Therefore, for example, even when the infrared light absorption characteristics of the infrared light absorbing member 131 deteriorate with time and reflect infrared light, the infrared light reaching the infrared light absorbing member 131 is The light is reflected in a direction different from the inclined portion 51a (that is, the optical path X), and the amount of reflected light that is not related to the presence / absence detection of the ink detected by the infrared light receiving element 19b of the ink sensor 19 is suppressed. It can be done.

  On the other hand, when the ink 71 in the sub ink storage chamber 45 is consumed, the infrared light emitted from the infrared light emitting element 19a of the ink sensor 19 is as shown in FIG. Since the refractive index of the material of the (optical path X) and the inclined portion 51a (prism 52) is different from the refractive index of air, the light is reflected at the interface between the prism 52 and air (optical path Y). Therefore, the amount of reflected light received by the infrared light receiving element 19b of the ink sensor 19 is large (a certain value or more).

  As described above, according to the ink cartridge 130 of the second embodiment, the infrared light absorbing member 131 can absorb infrared light that is not related to the detection of the presence or absence of ink. The amount of reflected light that is reflected varies greatly depending on the presence or absence of ink, and the difference in the amount of light is detected using the infrared light receiving element 19b of the ink sensor 19 to be stored in the ink cartridge 130. The presence or absence of ink can be accurately detected.

  Further, since the inclined portion 51a (prism 52) and the infrared light absorbing member 131 are disposed above the sub ink storage chamber 45, before all the ink 71 in the ink cartridge 130 is consumed. The presence or absence of ink can be determined with a margin.

  In addition, as an above-mentioned infrared absorption member, the publicly known well-known infrared absorption member can be selected suitably, and can be used. For example, V (vanadium), Fe (iron), Cu (copper), Co (cobalt), Ni (nickel) or the like may be used alone or mixed with a plurality of types using a glass material as a base material. . In addition, the base material is not limited to solid and liquid, but, for example, metal chelate compound of acetylacetone, anthraquinone compound, naphthoquinone compound, diaminedisethylenethiolatonickel derivative, aromatic diammine metal complex, aromatic dithiol metal complex, A base material containing an infrared absorbent such as an aliphatic dithiol metal complex may be used. Moreover, you may use what has the filter characteristic which absorbs the light wavelength of a specific area | region, and the thing whose absorption factor of infrared light with a light wavelength of 700 nm-900 nm is 90% or more is especially desirable.

  The electrical configuration of the color inkjet printer 1 of the second embodiment is the same as the electrical configuration of the color inkjet printer 1 of the first embodiment shown in FIG. 6, and the color inkjet printer of the second embodiment. Since each process executed in 1 is the same as each process executed in the color inkjet printer 1 of the first embodiment shown in FIGS. 7 to 10, the description thereof is omitted.

  As described above, as described in the above embodiments, according to the image forming apparatus of the present invention, light is irradiated non-perpendicularly on the irradiated surface of the ink cartridge 2 and the amount of reflected light is detected by the optical detector. The detected amount of reflected light is compared with a threshold value for verifying the absence of ink and a threshold value for verifying that the ink cartridge is not installed, so that the absence of ink and no ink cartridge can be verified. . Therefore, the presence / absence of the ink 71 and the presence / absence of the ink cartridge can be accurately detected based on the reflected light reflected from the ink cartridge 2.

  Further, an error between the actual detection position of the ink cartridge 2 and the theoretical detection position is calculated, and based on the calculated error, the position of the carriage 5 is corrected when verifying that there is no ink or no ink cartridge is installed. To do. For this reason, even if the detection position of the ink cartridge 2 by the ink sensor 19 shifts from the original position due to an attachment error of the ink sensor 19, the shift can be corrected and the reflected light amount can be detected accurately. Can do.

  In addition, this invention is not limited to an above-described Example, In the range which does not change the summary of this invention, a deformation | transformation is possible suitably. For example, in the first embodiment, the inclined portion 51a is formed in an inclined state so that the opposing surface of the inclined portion 51a and the reflecting member 53 is inclined by approximately 20 degrees. However, the present invention is limited thereto. Instead of tilting the inclined portion 51a, the reflecting member 53 may be tilted. Even in this case, the same effects as in the first embodiment can be obtained.

  Further, in the first embodiment, the reflecting member 53 is formed in a bag shape, and the air reaching the reflecting member 53 is reflected by filling the bag-shaped interior with the air 72. As long as it can reflect the light that reaches the light beam, it may be constituted by a reflection plate. Further, although the reflection member 53 is separately provided in the sub ink storage chamber 45, the partition wall 42 that partitions the main ink storage chamber 44 and the sub ink storage chamber 45 may be configured as the reflection member 53.

  Moreover, in the said 2nd Example, although the inclination part 51a with which infrared light is irradiated was comprised inclined with respect to the infrared-light absorption member 131, these inclination part 51a and the infrared-light absorption member 131 are comprised. And may be configured to be parallel to each other. 13A and 13B are side views of the ink cartridge 140 and the ink sensor 19. As shown in FIGS. 13A and 13B, the side wall 51 is linear when viewed from the side. The ink cartridge 140 may be configured such that the infrared light absorbing member 141 and the side wall 51 (prism 52) are arranged in parallel. The principle of ink presence / absence detection is the same as described above, and will not be described. In this case as well, the infrared light absorbing member 141 is placed on the optical path X of the infrared light emitted from the infrared light emitting element 19a. By arranging it, it is possible to accurately detect the presence or absence of ink.

  In the second embodiment, the partition wall 42 or the foam 48 may be configured as an infrared light absorbing member. Further, the infrared light absorbing members 131 and 141 may be housed inside the reflecting member 53 formed in the bag shape shown in the first embodiment. In this case, since the infrared light absorbing members 131 and 141 can be disposed in the ink cartridge in a state of being separated from the ink 71, for example, a material that is inferior in ink resistance or a material that adversely affects ink. Even a member made of the above can be used as a light absorbing member. Further, since the infrared light absorbing member can be sealed using the inside of the reflecting member 53 formed in the bag shape, the infrared light absorbing member can also be constituted by a liquid.

  In each of the above embodiments, the color ink jet printer 1 is used as the image forming apparatus. However, the present invention is not limited thereto, and can be applied to, for example, an ink jet copying machine or a facsimile machine. it can. Further, although four ink cartridges 2 are mounted on the color ink jet printer 1, a configuration may be adopted in which one or more predetermined number of ink cartridges 2 are mounted.

In each of the above embodiments, the correction value for correcting the deviation between the original detection position and the actual detection position is calculated based on one reference ink cartridge 2 in the calibration data input process. In the calibration process (S15), the position of the ink cartridge 2 is corrected using the calculated first correction value. However, instead of this, the correction value is detected for each ink cartridge 2, or the correction value is detected for the ink cartridges 2 at both ends, and the position of the ink cartridge 2 is corrected based on each detected correction value. May be. Thereby, the reflected light from the ink cartridge 2 can be detected more accurately at an accurate detection position.

  In each of the above embodiments, one counter (first to fourth counters 94b to 94e) is provided corresponding to one ink cartridge 2. In the ink detection process, the counter detects the ink detection interval. When the near empty flags 94f to 94i are turned on, the first to fourth counters 94b corresponding to the turned on near empty flags 94f to 94i. The count value of .about.94e is cleared to 0, and the number of ink ejections is newly counted up to the empty threshold value. However, instead of this, two counters are provided corresponding to one ink cartridge, and in the ink detection process, the total number of ink ejections from the first counter until the ink becomes empty is counted in one counter. In this counter, the detection interval may be counted according to the number of ink ejections.

1 is a perspective view of a color inkjet printer to which an ink cartridge according to a first embodiment of the present invention is mounted. FIG. 6 is a side view illustrating a state where the ink cartridge is mounted on the head unit. (A) is a sectional side view of the ink cartridge 2, (b) is a partial sectional view taken along the line IIIb-IIIb in FIG. 3 (a), and (c) is a perspective view of the bottom of the ink cartridge 2. It is. (A), (b) is a side view of an ink cartridge and an ink sensor. It is a top view of an ink cartridge and an ink sensor. 1 is a block diagram illustrating an outline of an electric circuit configuration of a color inkjet printer 1. It is the figure which showed the flowchart of the calibration data input process which is one of the control programs. It is the figure which showed the flowchart of the ink detection process which performs the detection of an ink. It is the figure which showed the flowchart of the calibration process performed in the ink detection process of FIG. FIG. 6 is a diagram illustrating a flowchart of ink cartridge detection processing. FIG. 6 is a diagram schematically illustrating a change in reflected light level of an ink cartridge. (A), (b) is a side view of the ink cartridge and the ink sensor in the second embodiment. (A), (b) is a side view of the ink cartridge and the ink sensor in the second embodiment.

2 (2a to 2d) Ink cartridges 41, 42 Partition wall 43 Air introduction chamber (air chamber)
44 Main ink storage chamber (main storage chamber, part of ink storage chamber)
45 Sub-ink storage chamber (sub-storage chamber, part of ink storage chamber)
46 Bottom wall (ink supply port and first recess formation surface)
47 Air communication port (open air communication hole)
48 foam (porous material)
50 Ink supply port 55 First fitting recess (first recess)
56 Upper wall (second recess or first protrusion forming surface)
56a First upper wall (second recess forming surface on the ink supply port side)
56b Second upper wall 57 Second fitting recess (second recess)
58 Side wall plate (side wall)
59 Handle (second protrusion)
61 Rib 62 First convex portion (first protrusion)
71 ink

Claims (4)

An ink cartridge and an ink ink supply port capable of supplying to the outside to be stored in the ink chamber of the storable ink storage chamber and its ink,
A carriage on which a head unit including a print head for printing on a recording medium is mounted;
A drive unit that reciprocates the carriage in a linear direction,
In the ink jet printer in which the ink cartridge is attached to the head unit,
The ink cartridge is
The bottom wall,
An upper wall facing the bottom wall;
A first recess formed for positioning the ink cartridge;
With
In the bottom wall, the ink supply port is formed on one end side, and the first recess is formed on the other end side,
The head unit includes a placement portion on which the mounted ink cartridge is placed, and a fixing arm for fixing the ink cartridge placed on the placement portion,
The placement portion includes a fitting convex portion into which the first concave portion is fitted , and an ink supply passage communicating with the ink supply port.
The fixed arm is pivotally supported so as to be swingable, and presses the upper wall of the ink cartridge placed on the placement portion in a downward direction .
Positioning of the ink cartridge while preventing the ink cartridge from rotating around the ink supply port when the carriage is moved by fitting the first concave portion and the fitting convex portion. do,
An inkjet printer characterized by the above. The ink cartridge is in a position corresponding to the substantially central portion of said ink supply port and said first recess in said top wall, and a second recess is formed,
The fixed arm has a locking claw that fits into the second recess,
A pair of side walls erected in the longitudinal direction of a pair of opposed surfaces opposed in the movement direction are formed on both sides of the carriage in the movement direction of the second recess of the ink cartridge mounted on the carriage. And
2. The inkjet printer according to claim 1 , wherein an interval between the pair of side walls in the moving direction is formed to have a width equivalent to that of the locking claw fitted in the second recess . The ink cartridge communicates with an air chamber having an outside air communication hole communicating with outside air, a main reservoir chamber having a porous body that is in communication with the air chamber and can be impregnated with the ink, and the main reservoir chamber. the ink jet printer according to claim 1 or claim 2, characterized in that the ink in the main reservoir is divided into a sub-reservoir which communicates with the air chamber after being discharged bets both. Outside air communication hole, according to claim 3, wherein said ink supply port and the first recess is provided in the formed surface, and is disposed between the ink supply port first recess Inkjet printer.

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