JP2011037008A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording device detecting a negative pressure lever with high accuracy without enlarging the device even of two-head and four-tank configuration. <P>SOLUTION: The inkjet recording device includes two sub-tanks 15 provided for one recording head 14. The two sub-tanks 15 include negative pressure levers 106A, 106B respectively, and the negative pressure levers 106A, 106B are arranged apart in a direction orthogonal to a main scanning direction and detected by individual full tank detecting sensors 200A, 200B. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus including a sub tank.

  In an ink jet recording apparatus used as various image forming apparatuses such as a printer, a facsimile, a copying apparatus, and a plotter, a small-capacity sub tank for supplying ink, which is a liquid, to an ink jet head that is a recording head is mounted on a carriage. An apparatus in which a large-capacity ink cartridge (main tank) is installed on the apparatus main body side, and ink is replenished and supplied from the main tank on the apparatus main body side as the sub tank is consumed is described in Patent Document 1 and the like. ing.

  This type of ink jet recording apparatus uses four color recording inks of yellow (Y), cyan (C), magenta (M), and black (Bk), and four heads 4 each having a sub tank in the head for each color. Although an apparatus having a tank configuration is common, as shown in FIG. 13, an inkjet recording apparatus having a 2-head 4-tank configuration in which two sub-tanks are provided in one head is also described in Patent Document 2 and the like.

  13A and 13B, in the subtank structure, reference numerals 301 and 301A are provided inside the subtank 300, and are negatively applied by a spring (not shown) that biases the film 302 (one film is not shown). This is a negative pressure lever that operates following the film 302 that is displaced according to the consumption of ink stored in the sub tank generating pressure. The supply ports 303 and 303A are supply ports through which ink is supplied from an ink cartridge (not shown) via an ink supply tube (not shown). In addition, the air release pins 304 and 304A are pins that open the inside of the sub tank to the atmospheric state as necessary. Further, a recording head 305 for ejecting ink droplets is attached below the sub tank.

  In the ink jet recording apparatus having such a subtank structure, the negative pressure levers 301 and 301A that operate following the film 302 are detected by the one sensor 400 provided on the apparatus main body side to detect the feelers 306 and 306A of all the levers. The amount of movement is detected by and the amount of consumption is calculated. For this reason, in order to increase the detection accuracy, it is advantageous that the amount of movement of the negative pressure lever with respect to a certain amount of ink is larger. Therefore, the longer the length of the negative pressure lever, the larger the amount of movement and the more advantageous.

  In the ink jet recording apparatus having a two-head four-tank configuration, as described above, the tips of all the levers are detected by one sensor. However, in the two-head four-tank device, the two adjacent levers are close to each other, so in rare cases such as when both the ink is consumed greatly, the levers of the adjacent sub-tanks may overlap, leading to erroneous detection. It was. To solve this problem, it may be possible to suppress the lever movement by strengthening the spring that biases the film 302 or shortening the lever, but this deteriorates the detection accuracy and decreases the supply amount. Resulting in. In addition, it is conceivable to arrange the levers so as not to interfere with each other, but there is a problem that the apparatus becomes large.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording apparatus that can detect a negative pressure lever with high accuracy without increasing the size of the apparatus even with a two-head four-tank configuration.

  In order to achieve the above object, the present invention provides a plurality of recording heads for ejecting ink to a carriage mounted on the apparatus main body so as to be movable in the main scanning direction of the recording medium, and a sub tank for supplying ink to the recording head. The sub tank is provided with a negative pressure lever that is displaced in the main scanning direction in accordance with the amount of ink stored, and the position of the negative pressure lever is detected by a sensor provided in the apparatus main body, and the detected negative pressure is detected. An ink jet recording apparatus in which ink is replenished from a main tank to a sub tank according to a position of a lever, wherein the two sub tanks are provided for one recording head. Each of the negative pressure levers is provided, and the negative pressure levers are arranged apart from each other in a direction perpendicular to the main scanning direction. It proposes an ink jet recording apparatus characterized by being detected by the sensor.

  In the present invention, the interval in the main scanning direction of the negative pressure lever provided in each of the two sub-tanks for the one recording head is equal to the interval in the main scanning direction of the two sensors, and the two sensors are simultaneously It is advantageous to detect the negative pressure lever.

  Further, in the present invention, when two recording heads provided with the two sub-tanks are provided, the negative pressure levers of the sub-tanks facing each other between the recording heads are separated in a direction perpendicular to the main scanning direction. And is advantageous.

  According to the present invention, each of the two sub-tanks includes the negative pressure lever, the negative pressure levers are arranged apart from each other in a direction orthogonal to the main scanning direction, and the negative pressure levers are separated by individual sensors. Therefore, the negative pressure lever can be detected with high accuracy without increasing the size of the apparatus even in the case of the two-head four-tank configuration.

FIG. 3 is a perspective explanatory view seen from the front side of the ink jet recording apparatus having a sub tank according to the present invention. FIG. 2 is a configuration diagram illustrating an outline of a mechanism unit of the recording apparatus. It is principal part plane explanatory drawing of the mechanism part. FIG. 3 is an explanatory diagram illustrating an example of a nozzle row of a recording head. It is a disassembled perspective explanatory drawing of the part concerning an ink supply apparatus. It is a disassembled perspective explanatory drawing of a sub tank. It is typical side surface explanatory drawing of the same sub tank. It is a schematic sectional explanatory drawing which follows the AA line of FIG. It is a flowchart with which it uses for description of the open air filling operation | movement to the sub tank in a recording device. (A) is a perspective view of the sub tank in this embodiment, (b) is the side view. It is explanatory drawing which shows arrangement | positioning of a full tank detection sensor. It is a perspective view which shows the full tank detection sensor. (A) is a perspective view of the conventional sub tank, (b) is the side view. FIG. 10 is a diagram illustrating a problem in a conventional recording apparatus. It is a graph explaining the relationship between the amount of ink consumption, head negative pressure, and the amount of movement of the feeler of a negative pressure lever.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is an explanatory perspective view of an ink jet recording apparatus according to the present invention as viewed from the front side.
The ink jet recording apparatus shown here includes an apparatus main body 1, a paper feed tray 2 for loading paper that is a recording medium mounted on the apparatus main body 1, and paper discharge for stocking the paper on which image recording has been completed. And a tray 3. Further, the front surface 4 of the apparatus main body 1 has a cartridge loading portion 6 that protrudes from the front surface 4 to the front side at one end side thereof and is lower than the upper surface 5. An operation unit 7 such as a vessel is arranged. The cartridge loading unit 6 has a front cover 8 that can be opened and closed for detaching the ink cartridge 10 as a main tank.

  In the apparatus main body 1, as shown in FIGS. 2 and 3, the carriage 13 is slid in the main scanning direction by a guide rod 11 and a stay 12 which are guide members horizontally mounted on left and right side plates (not shown). It is held movably and moved and scanned in the direction of the arrow in FIG. 3 by a main scanning motor (not shown).

  The carriage 13 is provided with a recording head 14 composed of four inkjet recording heads that eject recording ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk). The ejection ports are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.

  The inkjet recording head constituting the recording head 14 includes a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by liquid film boiling using an electrothermal transducer such as a heating resistor, and a metal phase caused by a temperature change. A shape memory alloy actuator using a change, an electrostatic actuator using an electrostatic force, or the like provided as energy generating means for discharging recording ink can be used.

  In addition, the carriage 13 is equipped with a sub tank 15 for each color for supplying ink of each color to the recording head 14. The sub-tank 15 is supplied with and supplemented with the recording ink of the present invention from the ink cartridge 10 of the present invention loaded in the ink cartridge loading section 6 via a recording ink supply tube (not shown).

  On the other hand, as a paper feeding unit for feeding the paper 22 stacked on the paper stacking unit (pressure plate) 21 of the paper feeding tray 2, a half-moon roller (feeding) that separates and feeds the paper 22 one by one from the paper stacking unit 21. The paper roller 23) and a separation pad 24 made of a material having a large friction coefficient are provided opposite to the paper feed roller 23, and the separation pad 24 is urged toward the paper feed roller 23 side.

  As a transport unit for transporting the paper 22 fed from the paper feed unit below the recording head 14, a transport belt 31 for transporting the paper 22 by electrostatic adsorption and a guide 25 from the paper feed unit. The counter roller 32 for transporting the paper 22 fed via the transport belt 31 with the transport belt 31 and the paper 22 fed substantially vertically upward are changed by about 90 ° to be copied on the transport belt 31. A conveying guide 33 and a tip pressure roller 35 urged toward the conveying belt 31 by the pressing member 34, and a charging roller 36 as a charging means for charging the surface of the conveying belt 31. It has been.

  The conveyance belt 31 is an endless belt, is stretched between the conveyance roller 37 and the tension roller 38, and can circulate in the belt conveyance direction. A guide member 77 is disposed on the back side of the conveyance belt 31 so as to correspond to a printing area by the recording head 14. As a paper discharge unit for discharging the paper 22 recorded by the recording head 14, a separation claw 51 for separating the paper 22 from the conveyance belt 31, a paper discharge roller 52, and a paper discharge roller 53 are provided. The paper discharge tray 3 is disposed below the paper discharge roller 52.

  A double-sided paper feeding unit 61 is detachably attached to the back surface of the apparatus main body 1. The double-sided paper feeding unit 61 takes in the paper 22 returned by the reverse rotation of the transport belt 31, reverses it, and feeds it again between the counter roller 32 and the transport belt 31. A manual paper feed unit 62 is provided on the upper surface of the duplex paper feed unit 61.

  In this ink jet recording apparatus, the paper 22 is separated and fed one by one from the paper feed unit, and the paper 22 fed substantially vertically upward is guided by the guide 25 and between the transport belt 31 and the counter roller 32. It is sandwiched and conveyed. Further, the front end is guided by the transport guide 33 and pressed against the transport belt 31 by the front end pressure roller 35, and the transport direction is changed by approximately 90 °.

  At this time, the conveyance belt 37 is charged by the charging roller 36, and the sheet 22 is conveyed by being electrostatically attracted to the conveyance belt 31. Therefore, by driving the recording head 14 according to the image signal while moving the carriage 13, ink droplets are ejected onto the stopped paper 22 to record one line, and after the paper 22 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 22 has reached the recording area, the recording operation is finished and the paper 22 is discharged onto the paper discharge tray 3.

  Then, when it is detected that the remaining amount of recording ink in the sub tank 15 has decreased, a required amount of recording ink is supplied from the ink cartridge 10 to the sub tank 15.

  Here, an example is described in which the present invention is applied to a serial (shuttle type) ink jet recording apparatus that is scanned by a carriage, but the present invention can be similarly applied to a line type ink jet recording apparatus having a line type head.

  Here, the recording head 14 (used to collectively refer to a plurality of heads) is, for example, as shown in FIG. 4, a nozzle row 14yn including a large number of nozzles N that eject yellow (Y) ink droplets, and magenta ( M) a droplet discharge head 14 a having a nozzle row 14 mn composed of a number of nozzles N that eject ink droplets of M, a nozzle array 14 cn composed of a number of nozzles N that eject cyan (C) ink droplets, and black (Bk) ) And a head 14b having a nozzle row 14kn composed of a number of nozzles N that eject ink droplets.

  As the ink-jet head constituting the recording head 14, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that utilizes a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. A shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, or the like provided as energy generating means for discharging ink can be used. In the embodiments described later, a head using a piezoelectric actuator (piezoelectric element) as energy generating means is mounted.

  Further, the carriage 13 has a sub tank 15 which is a liquid container of each color for supplying each color ink to each nozzle row 14yn, 14mn, 14cn, 14kn of the recording head 14 (if each color is distinguished, the nozzle row The codes 15y, 15m, 15c, and 15k are used correspondingly). The sub-tank 15 uses the main tank (ink cartridge) 10 for each color described above via the ink supply tube 16 (in order to distinguish each color, the symbols 10y, 10m, 10c, and 10k are used corresponding to the nozzle rows. ) Is replenished and supplied. Here, the main tank 10 stores ink of each color of yellow (Y), cyan (C), magenta (M), and black (Bk) corresponding to each color, but the main tank 10 stores black ink. The tank 10k has a larger ink storage capacity than the main tanks 10y, 10m, and 10c that store other color inks.

  Next, details of the ink supply device in this recording apparatus will be described with reference to FIGS. 5 is an exploded perspective view of a portion related to the ink supply device (a negative pressure lever is omitted), FIG. 6 is a perspective view showing only one sub tank, and FIG. 7 is a schematic diagram of the sub tank. FIG.

  As described above, the ink supply device is mounted on the carriage 13 and supplies a sub tank 15 which is a liquid container for supplying ink to each recording head 14 (14a, 14b), and the sub tank 15 is supplied with ink via a supply tube 16. And a main tank (ink cartridge) 10 for supply and replenishment.

  One sub tank 15 is a flexible film-like member that seals an opening (one surface of the sub tank 15) of the ink storage unit 100 to a container main body (case main body) 101 that forms the ink storage unit 100 that stores ink. (Flexible film-like member) 102 is attached by bonding or welding, and further, the film-like member 102 is biased outwardly between the case main body 101 and the film-like member 102 inside the ink containing portion 100. A spring (spring) 103 which is an elastic member is provided.

  Here, the film-like member 102 may have a single-layer structure, but as shown in FIG. 8A, a two-layer structure in which different types of first layer 102a and second layer 102b are laminated, for example, polyethylene and A structure in which a nylon film-like member is laminated, or a structure in which a silica vapor deposition layer 102c is formed on the first layer 102a as shown in FIG. By adopting such a configuration, it is possible to ensure liquid resistance against ink. Moreover, the liquid resistance with respect to the ink accommodated can also be improved by including a silica vapor deposition layer in the film-like member 102.

Moreover, as for the thickness of the film-like member 102, 10-100 micrometers is preferable. If the thickness is less than 10 μm, damage due to deterioration over time may easily occur, and if it exceeds 100 μm, flexibility may be reduced and efficient generation of negative pressure may be difficult.
Furthermore, a bulging portion 102 a having a convex shape corresponding to the spring 103 is formed on the film-like member 102, and a reinforcing member 104 is attached to the outer surface thereof. In this manner, by providing the flexible film-like member 102 with the convex portion, the elastic member (here, the spring) 103 can be stably held. In this case, the flexible film-like member 102 can be easily formed with a convex portion by forming a sheet-like film member into a convex shape.

  Further, the case 101 is provided with an ink introduction path portion 111 for replenishing ink in the ink containing portion 100, and a connecting means for connecting the ink introduction path portion 111 and the supply tube 16 connected to the ink cartridge 10. 112 can be detachably mounted. A liquid feed pump as described later is provided between the ink cartridge 10 and the sub tank 15 in order to pressure-feed ink from the ink cartridge 10 to the sub tank 15.

  Further, a connecting member 113 for supplying ink from the ink containing portion 100 to the recording head 14 is attached to the lower portion of the case 101, and an ink supply path 114 of the recording head 14 is formed in the connecting member 113. A filter 115 is interposed between the two.

  An air flow path 121 is formed in the upper part of the case 101 for taking out air from the ink containing portion 100. The air flow path 121 includes an inlet flow path portion 122 having an opening facing the ink containing portion 100 and a flow path portion (referred to as an “orthogonal flow path portion”) 123 following the inlet flow path portion 122. An accumulation portion 126 is continuously formed in a portion that communicates with the atmosphere opening hole 131 provided in the case 101 on the downstream side, and that is further below the atmosphere opening hole 131 in use.

  The atmosphere release hole 131 is provided with an atmosphere release valve mechanism 132 which is an atmosphere release means for switching between the sealed state and the atmosphere release state in the sub tank 15. The atmosphere release valve mechanism 132 is configured by accommodating a valve seat 134, a ball 135 as a valve body, and a spring 136 for urging the ball 135 toward the valve seat 134 in a holder 133.

  The operation of the storage unit 126 will be described. When the apparatus main body is tilted or shaken, there is a high possibility that ink will enter the air flow path 121. Therefore, the ink that has entered from the air flow path 121 can be accumulated in the accumulating portion 126, and even if the ink falls and is intruded during transportation, the ink is placed in the atmosphere opening port 131 and the atmosphere opening valve mechanism 132 that opens and closes the ink. Prevents the atmosphere release valve mechanism 132 from malfunctioning due to intrusion and hardening.

  In addition, two detection electrodes 141 and 142 for detecting that the amount of ink in the sub tank 15 is equal to or less than a predetermined amount (this state is “no ink”) are attached to the upper portion of the case 101. ing. Detecting “no ink” by changing the conduction state between the detection electrodes 141 and 142 in a state where both the detection electrodes 141 and 142 are immersed in ink and in a state where at least one of the detection electrodes 141 and 142 is not immersed in ink Can do.

  Furthermore, as shown in FIG. 5, an air release pin 153 for releasing the air by pressing the ball 135 of the air release mechanism 132 of the sub tank 15 against the spring 136 is disposed so as to be able to advance and retreat. A drive unit 162 including a lever 161 for operating the atmosphere release pin 153 is disposed on the apparatus main body side.

  In the ink jet recording apparatus, as shown in FIG. 3, the nozzle state of the recording head 14 is maintained and recovered in a non-printing area on one side (or both sides) of the carriage 13 in the scanning direction. The maintenance / recovery mechanism 71 is arranged, but a detailed description of the maintenance / recovery mechanism is omitted because it is not the gist of the present invention.

Next, an ink replenishment supply operation to the sub tank in the image forming apparatus will be described.
In the ink supply device of this image forming apparatus, the operations for supplying and replenishing ink from the main tank 10 to the sub tank 15 include opening to the atmosphere with the sub tank 15 being opened to the atmosphere and supplying the ink to the sub tank 15 to the atmosphere. There is normal filling without supplying ink.

  Here, the atmosphere release filling operation will be described with reference to FIG. 9. The drive unit 162 operates the atmosphere release pin 153 to open the atmosphere release valve mechanism 132 of the sub tank 15 to open the sub tank 15. To open air. When the sub tank 15 is opened for standby, the film-like member 102 is pushed outward by the restoring force of the spring 103, so that the capacity of the sub tank 15 increases (the negative pressure generating portion expands).

  In this state, the ink is supplied from the ink cartridge 10 to the sub tank 15 by a liquid supply mechanism (not shown) and supplied. Thereafter, the atmosphere release valve mechanism 132 is closed to shut off the sub tank 15 from the atmosphere release. Then, the cap surfaces 72A and 72B of the maintenance / recovery mechanism 71 cap the nozzle surface of the corresponding head 14, drive a motor (not shown) to operate a suction pump (not shown), and supply the sub tank 15 to which ink has been supplied. Suction is performed from the nozzle side of the recording head 14 to discharge a predetermined amount of ink. As a result, the film-like member 102 of the sub tank 15 is deformed inwardly against the urging force of the spring 103 to reduce the volume of the sub tank 15 (the negative pressure generating portion contracts), and an initial negative pressure is generated.

Thereafter, the position of the detection end 106a of the negative pressure lever 106 is detected and stored by a full tank detection sensor 200 provided on the apparatus main body 1 side.
In addition, as a method for filling with open air, the following operation can be performed as another method. For example, after the sub tank 15 is opened to the atmosphere, the flexible film member 102 is pressed inward against the spring 103 by the negative pressure lever 106 to reduce the capacity of the sub tank 15, and then the ink cartridge 10. Then, the ink is supplied to the sub tank 15 by the liquid supply mechanism and replenished and supplied, and then the atmosphere release valve mechanism 132 is closed to shut off the inside of the sub tank 15 from the atmosphere release, and the pressure by the negative pressure lever 106 is released. By doing so, the flexible film-like member 102 is urged outward by the urging force of the spring 103, and a negative pressure is generated in the sub tank 15.

Thus, since the negative pressure can be generated in the sub-tank by the flexible film-like member and the elastic member, the negative pressure generating mechanism is simplified.
Next, normal filling will be described. In this case, as described above, the ink consumption V is detected (by counting the number of drops), and when the required consumption is reached, the sub tank 15 is opened to the atmosphere. Instead, the ink is supplied from the ink cartridge 10 to the sub-tank 15 by the liquid supply mechanism, and replenished and supplied by a required filling amount. The filling amount can be controlled by the driving time of the pump 181.

  Here, it is obvious that the replenishment amount of ink to be supplied is preferably the same as the consumption amount V. However, in practice, the calculation of the consumption amount V causes an error due to variations in the amount per droplet and the suction amount. Occurs. In addition, since the supply is a supply with pulsation due to the piston reciprocation, the supply amount varies depending on the timing. When ink consumption and normal filling are repeated, the actual ink amount in the sub tank 15 gradually shifts due to these errors. As a result, the negative pressure value in the sub tank 15 also shifts.

  Therefore, as described above, the position of the negative pressure lever 106 is stored when the initial negative pressure is formed by sucking a predetermined amount of liquid after filling in the atmosphere. As the ink in the sub tank 15 is consumed, the film-like member 102 is further recessed, so that the negative pressure lever 106 is moved (displaced) to the sub tank 15 side accordingly. During normal filling, the full tank detection sensor 200 reads that the position of the negative pressure lever 106 comes to the original stored position, and the filling operation is stopped there. As a result, errors due to variations as described above are reduced, and the original initial negative pressure can be maintained immediately after normal filling.

  As described above, the operation of releasing the atmosphere and supplying the ink to the sub tank 15 (filling with the atmosphere) need not be performed every time the ink in the sub tank 15 is consumed, and the ink consumption of the sub tank 15 is a certain amount. In other cases, it is preferable to perform an operation of replenishing and supplying ink to the sub tank 15 (normal filling) without releasing the atmosphere.

  In the ink jet recording apparatus configured as described above, it is necessary to accurately detect the position of the negative pressure lever 106 in replenishing ink. However, in the conventional apparatus using the sub tank 300 shown in FIG. ), The position of the negative pressure levers 301, 301A, 301B, 301C for four colors is detected by one full tank detection sensor 400. For this reason, the negative pressure levers 301 and 301A are substantially at the height level with no difference in the height direction as shown in FIG. 13B. However, with such a configuration, when the ink in the two sub tanks 300 provided in one head is consumed greatly at the same time or the adjacent sub tanks 300 in adjacent heads are simultaneously open to the atmosphere, FIG. As shown by points A and B), the tips of both negative pressure levers 106 overlap to detect both levers at the same time, causing a problem that the position of the feeler cannot be read.

  Therefore, in order to simply prevent the negative pressure lever 106 from overlapping, it is conceivable to increase the interval between the negative pressure levers by separating the head position or the like, but this increases the machine size. As another method, it is conceivable to reduce the amount of displacement of the negative pressure lever 106 so that the adjacent levers do not overlap. Cause a decline.

  FIG. 15 is a graph showing the relationship between ink consumption, head negative pressure, and feeler movement. In the apparatus of this example, the position of the feeler is proportional to the amount of consumption until approximately 17 cc of ink is consumed, and if the movement range of the feeler is 6.5 mm, the amount of consumption can be 1.7 cc. Negative pressure is up to -100. Here, if the spring 103 is strengthened to reduce the movement amount of the feeler to 4 mm, the consumption amount is up to 1.0 cc and ink is frequently filled.

  Therefore, in this embodiment, as shown in FIGS. 10A and 10B, the feelers 106a-A and 106a-B of the two negative pressure levers 106A and 160B in one head are perpendicular to the main scanning direction. They are arranged so as to be spaced apart in the vertical direction. In accordance with this, the sensor for detecting the negative pressure lever 106 provided on the apparatus main body also includes a full tank detection sensor 200A for the upper feeler 106a-A and a full tank detection sensor 200B for the lower feeler 106a-B in the vertical direction. Separated and provided.

  The ink jet recording apparatus of the present embodiment configured as described above detects the negative pressure levers 106 of the two sub tanks 15 by the separate full tank detection sensors 200A and 200B. The displacement amount of the pressure lever 106 is not reduced.

  By the way, the feelers 106a-A and 106a-B of the negative pressure levers 106A and 160B are separated from each other in the main scanning direction by an interval L when viewed from the front. Similarly, if the full tank detection sensors 200A and 200B are separated by an interval L in the main scanning direction, the feelers 106a-A and 106a-B of the negative pressure levers 106A and 160B are simultaneously moved when the recording head is moved to the detection position. Detection can be performed, and the detection time can be shortened.

  Furthermore, if the feelers 106a of the negative pressure levers 106 adjacent to each other of the two recording heads 14 are also arranged in the vertical direction, both the adjacent sub tanks 15 of the adjacent heads can be opened to the atmosphere at the same time. The feeler position of the negative pressure lever 106 can be detected without any trouble.

DESCRIPTION OF SYMBOLS 10 Ink cartridge 13 Carriage 14 Recording head 15 Sub tank 100 Ink accommodating part 102 Flexible film-like member 103 Elastic member 106 Negative pressure lever 200 Full sensor

Japanese Patent No. 4190001 JP-A-2005-320531

Claims (3)

A carriage mounted on the apparatus main body so as to be movable in the main scanning direction of the recording medium is equipped with a plurality of recording heads for ejecting ink and a sub tank for supplying ink to the recording head, and is accommodated in the sub tank. A negative pressure lever that is displaced in the main scanning direction according to the amount of ink is provided. An ink jet recording apparatus to which ink is replenished, wherein two sub tanks are provided for one recording head.
The two sub-tanks for the one recording head are each provided with the negative pressure lever, the negative pressure levers are arranged apart from each other in a direction perpendicular to the main scanning direction, and the negative pressure levers are individually provided. An ink jet recording apparatus that is detected by a sensor.   The interval in the main scanning direction of the negative pressure levers respectively provided in the two sub-tanks for the one recording head is equal to the interval in the main scanning direction of the two sensors, and the two sensors simultaneously detect the negative pressure levers. The inkjet recording apparatus according to claim 1, wherein:   2. When two sets of one recording head provided with the two sub tanks are provided, the negative pressure levers of the sub tanks facing each other between the recording heads are separated in a direction perpendicular to the main scanning direction. Item 3. The ink jet recording apparatus according to Item 1 or 2.

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