JP2005111944A - Ink-jet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink-jet recorder which dispenses with a maintenance such as filter exchange even if an ink in an ink tank contains any foreign substance and prevents the foreign substance from reaching a recording head and does not cause clogging in a nozzle of the head. <P>SOLUTION: The apparatus comprises an intermediate tank 5 in the middle of ink supply channels 2, 3 and 4 for supplying an ink from an ink tank 1 to a recording head 104. The intermediate tank 5 holds the ink to be supplied from the ink tank to the recording head, and comprises a foreign substance holding part 8, a tilting bottom 10, a foreign substance removal port 11 which can be opened and closed freely, an ink-receiving port 14 which is opened in the upper part of the intermediate tank, and an ink-supply port 15 which is opened in the ink in the intermediate tank. Thereby, the foreign substance which is mixed to the ink in the intermediate ink 5 and has a higher specific gravity than the ink precipitates in the foreign substance holding part 8, and the foreign substance can be taken out to the outside and removed by opening the foreign substance removal port 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus such as an ink jet printer, an ink jet copying machine, and an ink jet facsimile, and more particularly to an ink jet recording apparatus capable of removing foreign matters in ink used for ink jet recording.

  In an ink jet recording apparatus, ink is sent from an ink tank such as an ink cartridge to a recording head via an ink supply path, and recording is performed by ejecting ink from the recording head to the recording medium as an ink jet.

  The ink tank is removed when the ink is consumed, and a new ink tank is attached and replaced. During this replacement, foreign substances such as dust may be mixed from the outside. In addition, when the components of the ink itself elapse for a long period of time, they may rarely change over time to produce a solid denatured product, or in the case of pigment ink, a pigment aggregate may be produced.

  These foreign substances are coarse solids in the ink, and if they enter the ink jet nozzles of the recording head, the nozzles become clogged, resulting in defective ejection, which may cause recording failure or printing failure, or replacement of the print head. Sometimes it was necessary.

  In order to prevent clogging of the nozzles due to foreign matters in the ink, for example, as in Patent Document 1 and Patent Document 2, there is a technique for removing foreign matters by filtering the ink with a filter so that the foreign matters do not reach the recording head. Are known.

  Patent Document 1 discloses an ink jet recording apparatus in which a filter device 6 is provided in a supply path connecting the print head 1 and the ink cartridge 4, and foreign matter in the ink is blocked and removed by the filter 15 of the filter device 6. Has been.

  Patent Document 2 discloses an ink jet recording apparatus in which a filter 14 is provided in an ink flow path R <b> 1 from the ink tank 7 to the recording head 4, and foreign matter in the ink is blocked and removed by the filter 14. The decrease in the foreign matter removal capability due to the foreign matter adhering to the filter 14 is determined by the determination means.

  However, since foreign matter accumulates in the filter, it is necessary to periodically replace the filter in Patent Document 1, and in Patent Document 2, maintenance work such as filter replacement is necessary according to the determination result of the determination unit. There was a problem of becoming.

Japanese Patent No. 2999754 (4th page, right column, line 43 to 5th page, left column, 1st line, FIGS. 1 and 3)

Japanese Patent Laying-Open No. 2003-11380 (paragraph number 0018, FIG. 2)

  The present invention solves the above-mentioned problems, does not require maintenance such as filter replacement, and even if there is a foreign matter in the ink in the ink tank, the foreign matter does not reach the recording head, and the nozzle of the recording head due to the foreign matter It is an object of the present invention to provide an ink jet recording apparatus that does not cause printing failure or print head replacement due to clogging.

  In order to solve the above-described problems, the present invention includes an intermediate tank that is provided in the middle of an ink supply path that supplies ink from an ink tank to a recording head, and retains ink in the middle of supply. A foreign matter reservoir provided at the lowermost portion of the intermediate tank, a bottom surface inclined toward the foreign matter reservoir, an openable / closable foreign matter outlet provided at the bottom of the foreign matter reservoir, and the ink tank It has an ink receiving port that opens to the upper part of the intermediate tank and communicates with the ink supply path, and an ink supply port that opens to the ink in the intermediate tank and communicates with the ink supply path to the recording head.

  Further, in the above invention, the foreign object detector for detecting the degree of accumulation of the foreign substance accumulated in the foreign substance reservoir part, and the removal of the foreign object that opens the foreign object extraction port when the foreign object detection level of the foreign object detector rises to a predetermined level. Open / close means.

  Further, in the above invention, the foreign object detector for detecting the degree of accumulation of the foreign substance accumulated in the foreign substance reservoir portion, and the foreign object detection level of the foreign object detector is lowered to a predetermined level while the foreign object is being taken out from the foreign substance takeout port. In this case, a foreign matter taking-off opening / closing means for closing the foreign matter take-out port may be provided.

  Further, a foreign substance reservoir inlet opening / closing means that is disposed above the foreign substance reservoir part and is closed when the foreign substance removing opening / closing means is opened to shut off the foreign substance reservoir part and the ink above the inclined bottom surface. It can also be provided.

  Moreover, in the said invention, the foreign material rise-up shielding member which the upper side inclined can also be provided in the said intermediate tank.

  According to the present invention, when the specific gravity of foreign matter mixed from the outside or generated from ink is larger than the specific gravity of ink, and the ink is gently retained, the foreign matter in the ink gradually settles downward. In particular, foreign substances are separated from ink by a specific gravity difference and removed.

  According to the present invention, foreign matter in the ink sent from the ink tank to the recording head can be separated and removed by the difference in specific gravity with the ink, so that it is possible to transfer to the recording head without using a conventional filter that requires troublesome maintenance. Intrusion recording apparatus with high reliability can be obtained by eliminating the deterioration of image quality and replacement of the recording head.

  In this invention, the foreign matter accumulation degree is detected by the foreign matter detector by the foreign matter detector, and the foreign matter opening / closing means is opened according to the foreign matter detection level to remove the foreign matter from the foreign matter accumulation portion and remove it, or the removal is completed. Maintenance-free automation can be realized by closing the opening / closing means for taking out the foreign matter at times.

  Further, when the foreign matter removal opening / closing means is opened, if the foreign matter reservoir and the upper layer ink are blocked by the foreign matter reservoir entrance opening / closing means, the amount of foreign matter removed can be made constant, and maintenance can be performed. It becomes easier.

  In addition, if a foreign material soaking-up and blocking member is provided in the intermediate tank, it is possible to prevent foreign matter accumulated in the foreign matter reservoir from flying up into the upper ink layer due to vibration and being sent to the recording head side. .

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a sectional view showing an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is an explanatory view schematically showing a first example of an ink supply system of the ink jet recording apparatus shown in FIG. 3 is a block diagram showing a control system of the ink supply system shown in FIG.

  Since each part of the ink jet recording apparatus shown in FIG. 1 is well known, a detailed description thereof will be omitted, but an outline thereof will be described below.

  In FIG. 1, reference numeral 101 denotes a scanner unit that reads a document, and reference numeral 102 denotes a printer unit that records an image based on image information read from the document by the scanner unit 101.

The scanner unit 101 photoelectrically reads an original, and reads the read image signal in cyan (
C), converted into magenta (M), yellow (Y), and black (B) component color image signals and output.

  The printer unit 102 includes an image processing unit 103, an ink jet print head (ink jet recording head) 104, a paper feed unit 105, a paper discharge unit 106, a belt transport unit 107, and an operation panel unit 108.

  The image processing unit 103 stores the color image signal generated by the scanner unit 101 in a storage unit including a memory, and performs predetermined image processing on the color image signal to perform image processing. Outputs digital image signals.

  Based on the digital image signal, the ink jet print head 104 ejects ink jet toward the printing paper on the belt conveyance unit 107 to form an image corresponding to the original on the printing paper. The ink jet print head 104 is of a line type, and a large number of ink jet nozzles are arranged in a line in a direction orthogonal to the print paper transport direction by the belt transport unit 107, that is, a so-called main scanning direction. The ink jet print head 104 has a B component head 109, an M component head 110, a C component head 111, and a Y component head 112 for each color component. Are juxtaposed along.

  A plurality of printing sheets are placed on the paper supply unit 105, and the printing sheets are fed out one by one. The paper discharge unit 106 receives and stores printing paper on which an image is printed by the inkjet print head 104.

  The belt conveyance unit 107 has an endless belt having a large number of air intake holes, and drives the belt while sucking air from these air intake holes, and causes the printing paper from the paper supply unit 105 to adhere to the belt. Then, the lower side of the print head 104 is sent in accordance with the printing operation and conveyed to the paper discharge unit 106.

  The ink supply system shown in FIG. 2 is provided for each color. In other words, the inkjet recording head 104 is a recording head of any one of the colors 109 to 112 in FIG.

  In FIG. 2, 1 is an ink tank such as an ink cartridge, 2 to 4 are ink supply paths for supplying ink from the ink tank 1 to the ink jet recording head 104, and 5 is an intermediate (3, 4) of the ink supply path. An intermediate tank 6 for retaining ink in the middle of supply, and a suction pump 6 for supplying ink from the ink tank 1 to the intermediate tank 5 provided in the middle (between 2 and 3) of the ink supply path. , 6a is a motor for driving the suction pump 6, and 7 is a waste ink tank.

  The intermediate tank 5 includes a foreign matter reservoir 8 provided at the lowermost part of the intermediate tank, and an ink storage 9 that retains ink on the upper side, and a bottom surface 10 of the ink storage 9 is Inclined toward the foreign substance reservoir 8. As will be described later, this inclination is for the foreign matter that has settled in the ink to slide toward the foreign substance reservoir portion 8, and it is preferable to make the inclination steep as long as space is available. The ink container 9 and the foreign substance reservoir 8 of the intermediate tank 5 can be formed as an integral container. However, in the first embodiment, as shown in FIG. Is provided.

  A foreign matter outlet 11 is provided at the bottom of the foreign matter reservoir 8, and foreign matter opening / closing means (electromagnetic valve) 12 is attached to the foreign matter outlet 11. The foreign matter taking-off opening / closing means 12 and the waste ink tank 7 are connected by a waste ink guide path 13. The foreign matter taking-off opening / closing means 12 is normally closed so that ink and foreign matter in the foreign matter reservoir 8 do not flow out. The waste ink tank 7 is detachable from the waste ink guide path 13, and is removed and replaced when the waste ink is discarded.

  The intermediate tank 5 also communicates with an ink supply path 3 to the ink tank 1, and has an ink receiving port 14 that opens to the ink storage portion 9 above the intermediate tank, and an ink supply path 4 to the recording head 104. And an ink supply port 15 that opens into the ink in the intermediate tank 5.

  A foreign object detector 16 that detects the degree of accumulation of foreign substances that accumulate in the foreign substance reservoir 8 is provided around the foreign substance reservoir 8. In this embodiment, the foreign matter detector 16 uses a light transmission sensor that measures the light transmittance, and detects that the amount of foreign matter increases and the light transmittance of the foreign matter reservoir 8 decreases. Yes.

  Further, a foreign matter reservoir inlet / outlet means (electromagnetic valve) 17 is provided between the ink containing portion 9 and the foreign matter reservoir 8. This foreign matter reservoir entrance opening / closing means 17 is normally open so that ink and foreign matter can flow from the ink containing portion 9 to the foreign matter reservoir 8.

  Reference numeral 18 denotes a foreign matter reservoir portion ventilation opening / closing means (electromagnetic valve) provided between the foreign matter reservoir portion 8 and the vent pipe 19 between the atmosphere. The foreign matter reservoir vent opening / closing means 18 is normally closed and is opened when the foreign matter reservoir 8 is emptied or when ink is introduced from an empty state to allow the air in the foreign matter reservoir 8 to enter and exit. is there.

  Reference numeral 20 denotes a float incorporating a magnet. The float 20 is slidable on a guide shaft 21 installed vertically in the ink container 9 and floats on the upper surface of the ink. Move up and down. A plurality of hall elements (not shown) are installed outside the intermediate tank 5 along the guide shaft 21. The Hall element can be provided at the ink empty position and the ink full position, and can also be provided in the middle if necessary. The float 20 and the plurality of hall elements constitute an ink remaining amount detector (ink remaining amount detecting means). Note that the remaining ink amount detecting means can be replaced with other appropriate detecting means.

  Reference numeral 22 denotes a vent pipe that allows the air in the upper layer of the ink containing portion 9 to communicate with the atmosphere.

  In FIG. 3, 30 is a CPU that controls the entire apparatus, 31 is a ROM that stores programs and various parameters, 32 is a RAM that stores temporary data, 33 is an I / O port, and 34 is a foreign object. A / D converter for A / D converting an analog signal indicating the quantity, 35 is a motor drive circuit that outputs a motor drive signal based on the pump drive signal via I / O port 33, and 36 is the power-off of the device A timer 37 for measuring the standing time is a battery for the timer 36.

  The I / O port 33 is for receiving an ink remaining amount signal from the ink remaining amount detector, outputting a pump drive signal to the motor 6a, and outputting an opening / closing control signal to the solenoid valves 12, 17, and 18. .

  Next, the ink supply operation of the first embodiment will be described.

  When the print start button on the operation panel unit 108 is pressed, the scanner unit 101 operates to read a document, and the image processing unit 103 performs predetermined image processing on the read color image signal to obtain B, C, M, and B. Y digital image signals for each color component, and this digital image signal is sent to the corresponding ink jet print heads 109 to 112 in synchronization with the feed of the printing paper sent on the belt conveyance unit 107, and each of the print heads An ink jet is ejected from the ink jet nozzle to form a color copy image on the printing paper.

  In addition to the printing operation, the ink of the print heads 109 to 112 is also consumed in the periodic maintenance operation of the old ink discharge that is automatically performed when the operation of the recording apparatus is stopped for a predetermined time in preparation for the smooth ejection of the ink jet. .

  The ink of the print head 104 (109 to 112) is supplied from the intermediate tank 5 via the ink supply path 4. The ink remaining amount in the intermediate tank 5 gradually decreases, and when the ink remaining amount detector detects the ink empty position, the motor drive circuit 35 is activated, and the suction pump 6 sends the ink in the ink tank 1 to the intermediate tank 5, When the ink remaining amount detector detects the ink full position, the operation of the motor drive circuit 35 is stopped and the suction pump 6 is stopped. Thus, the ink level of the intermediate tank 5 is maintained between the ink full position and the ink empty position. Note that the ink empty position is not a position where the ink is completely exhausted in the ink container 9 but a position sufficiently above the ink supply port 15 at the tip of the ink supply path 4. That is, the ink supply port 15 is always opened in the ink in the intermediate tank 5. Further, the ink supply path 4 is disposed sufficiently away from the bottom surface 10 of the ink containing portion 9 in order to avoid the inflow of foreign matters during sedimentation.

  Further, the ink receiving port 14 at the end of the ink supply path 3 from the ink tank 1 may be opened in the ink containing portion 9 above the upper surface of the ink, as shown in the figure, or opened in the ink. Also good. In any case, when the ink is poured into the ink storage portion 9 by the pump 6, it is necessary to avoid the ink flow reaching the foreign matter reservoir 8 and causing the foreign matter to rise. For this purpose, it is desirable to reduce the pump flow rate, dispose the ink receiving port 14 away from the foreign substance reservoir 8, or set the ink receiving port 14 to be horizontal or slightly upward.

  By the way, as described above, when the ink tank 1 is replaced, foreign matter such as dust may be mixed from the outside, or foreign matter may be generated from the ink itself over time.

  The ink sent to the print head 104 (109 to 112) stays in the intermediate tank 5 at one end as described above. Even if the suction pump 6 is operated during the operation of the print head, this stay is maintained. When the ink stays in the intermediate tank 5, the foreign matter in the ink gradually settles and reaches the bottom surface 10 of the ink containing portion 9 or directly settles in the foreign matter reservoir portion 8. The foreign matter that has reached the bottom surface 10 gathers in the foreign matter reservoir 8 so as to slide on the inclined surface of the bottom surface 10.

  The foreign matter collected in the foreign matter reservoir 8 is moved to the waste ink tank 7 and removed together with the surrounding ink. The discharge of foreign matter to the waste ink tank 7 can be performed at various timings, and an example thereof will be described below.

(1) Foreign matter discharge when the recording apparatus is not operated for a long time Even if the recording apparatus is not operated, foreign matter is generated in the ink in the intermediate tank 5 over time. In addition, fine foreign matters mixed from the outside may precipitate over a long period of time. Therefore, when the power of the recording apparatus is turned off, the timer 36 is started to operate by the battery 37. Then, when the operator turns on the power, the timer 36 is compared with a predetermined time written in the ROM 31. When the count time of 36 exceeds the predetermined time, foreign matter (dirty ink) is discharged from the foreign matter reservoir 8 to the waste ink tank 7. Conventionally, foreign matter discharge operation is performed every time the power is turned on, and ink with less foreign matter is discharged when the power is turned off for a short time. However, the foreign matter discharge operation is performed only when the predetermined time is exceeded. By doing so, wasteful ink consumption can be prevented.

  Since it is desired to discharge only the foreign matter (dirty ink) in the foreign matter reservoir 8 to the waste ink tank 7 and leave the ink in the ink containing portion 9 as it is, the solenoid valves 12, 17 and 18 are set as follows. Opening and closing control is performed, and foreign matter in the foreign matter reservoir 8 is discharged to the waste ink tank 7.

  First, the opened electromagnetic valve (foreign substance reservoir inlet / outlet opening / closing means) 17 is closed to shut off the ink container 9 and the foreign substance reservoir 8. Next, the closed solenoid valve (foreign matter taking-off opening / closing means) 12 and the solenoid valve (foreign substance reservoir vent opening / closing means) 18 are opened. When the electromagnetic valve (foreign matter taking-off opening / closing means) 12 is opened, the foreign matter taking-out port 11 is opened. In this state, the foreign matter in the foreign matter reservoir 8 flows into the waste ink tank 7. Whether or not the foreign matter in the foreign matter reservoir 8 has been discharged can be detected by the foreign matter detector 16, so when the foreign matter detector 16 detects no foreign matter, the solenoid valve (foreign matter removing opening / closing means) 12 is closed, Next, the electromagnetic valve (foreign material reservoir inlet opening / closing means) 17 is opened. As a result, the ink in the ink containing portion 9 flows into the foreign matter reservoir portion 8. Thereafter, the electromagnetic valve (foreign substance reservoir ventilation / opening / closing means) 18 is closed to the initial state.

  Instead of using the foreign object detector 16, the operation for returning to the initial state may be performed after a predetermined time has elapsed since the electromagnetic valve 12 opened.

  Further, the discharge of foreign matter may be performed simultaneously for each color, or may be performed at different timings by writing different times for each color in the ROM 31 in accordance with the tendency of increasing foreign matter for each color. . Furthermore, foreign matter discharge is not limited to when the power is turned on, but by appropriately setting the operation start timing of the timer 36, while the power is on for a long time, during printing, during standby, or during the recovery operation of the recording head You can also do it.

(2) Foreign matter discharge when foreign matter is accumulated in the foreign matter reservoir 8 When the foreign matter in the foreign matter reservoir 8 is increased, the light transmittance is lowered and the foreign matter detection level of the foreign matter detector 16 is increased. Therefore, when the foreign matter detection level and light transmittance of the foreign matter detector 16 reach predetermined levels, the electromagnetic valves 12, 17, and 18 are controlled to open the foreign matter takeout port as in the case of (1) above. 11 to remove foreign matter.

  FIG. 4 is an explanatory view schematically showing a second embodiment of the ink supply system of the ink jet recording apparatus shown in FIG.

  The ink supply system shown in FIG. 4 is provided for each color. In other words, the inkjet recording head 104 is a recording head of any one of the colors 109 to 112 in FIG.

  4, the same parts as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 4, the foreign substance reservoir 8 and the ink container 9 of the intermediate tank 5 are integrally formed, and two electromagnetic valves, the foreign substance reservoir inlet opening / closing means 17, the foreign substance reservoir ventilation opening / closing means 18, and the ventilation pipe 19 are provided. It is abolished and the cost is reduced. The foreign matter reservoir 8 integrated with the ink containing portion 9 can have a smaller cross-sectional area on the upper surface and a depth deeper than the diameter of the upper surface so that the deposited foreign matter is less likely to rise by vibration or ink flow. desirable.

  The removal of foreign matter deposited in the foreign matter reservoir 8 is performed by opening and closing an electromagnetic valve (foreign matter removing opening / closing means) 12. The timing of taking out can be performed in the above (1) and (2) as in the first embodiment.

  In the second embodiment, when the foreign matter is taken out, the ink in the ink containing portion 9 tends to flow out somewhat to the waste ink tank 7, but there is no practical problem.

  The third embodiment is a modification of the intermediate tank 5 of the second embodiment, and FIG. 5 schematically shows the intermediate tank portion. In FIG. 5, the same parts as those in FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 5, the intermediate tank 5 has a bowl shape in which the space between the foreign matter reservoir 8 and the ink storage portion 9 is constricted, and this constriction prevents the foreign matter from rising in the foreign matter reservoir 8 due to vibration or ink flow. It is out. Other configurations and operations are the same as those of the second embodiment.

  FIG. 6 is an explanatory view schematically showing a fourth embodiment of the intermediate tank of the ink jet recording apparatus shown in FIG. 6, the same parts as those in FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted.

  In FIG. 6, a plurality of foreign material rising and blocking members 51 whose upper side is inclined are provided in the ink containing portion 9 of the intermediate tank 5. When the upper side is inclined, the foreign matter that has fallen on the upper surface of the shielding member 51 does not stay there, and further falls in the ink. Even if the shielding member 51 is present, the foreign matter quickly moves toward the foreign matter reservoir 8.

  When the foreign matter in the foreign matter reservoir 8 rises due to vibration or the like, the foreign matter is prevented from rising by the shielding member 51, and foreign matter does not flow into the inkjet print head 104 from the ink supply port 15.

  As shown in the figure, when the foreign matter soaking-up and blocking member 51 is disposed so as to be inclined upwardly from the foreign matter reservoir portion 8, the foreign matter that has fallen on the upper surface of the shield member 51 slides on the upper surface of the shield member 51 and the foreign matter reservoir portion. It will be easier to get to 8. Other configurations and operations are the same as those of the second embodiment.

1 is a cross-sectional view illustrating an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is an explanatory diagram schematically illustrating a first embodiment of an ink supply system of the ink jet recording apparatus illustrated in FIG. 1. FIG. 3 is a block diagram showing a control system of the ink supply system shown in FIG. 2. FIG. 3 is an explanatory diagram schematically showing a second embodiment of the ink supply system of the ink jet recording apparatus shown in FIG. 1. FIG. 4 is an explanatory diagram schematically showing a third embodiment of the intermediate tank of the ink jet recording apparatus shown in FIG. 1. Explanatory drawing which shows typically 4th Example of the intermediate | middle tank of the ink jet type recording apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ink tank 2-4 Ink supply path 5 Intermediate tank 6 Suction pump 6a Motor 7 Waste ink tank 8 Foreign substance accumulation part 9 Ink storage part 10 Bottom face 11 Foreign substance taking out port 12 Foreign matter taking-off opening / closing means (electromagnetic valve)
13 Waste ink guide path 14 Ink receiving port 15 Ink supply port 16 Foreign matter detector 17 Foreign matter reservoir inlet opening / closing means (solenoid valve)
18 Foreign matter reservoir ventilation opening / closing means (solenoid valve)
19 Vent pipe 20 Float 21 Guide shaft 22 Vent pipe 30 CPU
31 ROM
32 RAM
33 I / O port 34 A / D converter 35 Motor drive circuit 36 Timer 37 Battery 51 Foreign matter rising shielding member 101 Scanner unit 102 Printer unit 103 Image processing unit 104 Inkjet print head (inkjet recording head)
105 Paper Feed Unit 106 Paper Discharge Unit 107 Belt Transport Unit 108 Operation Panel Unit

Claims (5)

An intermediate tank is provided in the middle of an ink supply path for supplying ink from the ink tank to the recording head, and retains ink in the middle of supply,
In the intermediate tank,
A foreign matter reservoir provided at the bottom of the intermediate tank;
A bottom surface inclined toward the foreign substance reservoir,
An openable and closable foreign matter outlet provided at the bottom of the foreign matter reservoir,
An ink receiving port that leads to an ink supply path to the ink tank and opens in an ink containing portion at the top of the intermediate tank;
An ink jet recording apparatus comprising: an ink supply port that communicates with an ink supply path to the recording head and opens into the ink in the intermediate tank. A foreign matter detector for detecting the degree of accumulation of foreign matter that accumulates in the foreign matter reservoir,
2. An ink jet recording apparatus according to claim 1, further comprising: a foreign matter removal opening / closing means that opens the foreign matter removal opening when the foreign matter detection level of the foreign matter detector rises to a predetermined level. A foreign matter detector for detecting the degree of accumulation of foreign matter that accumulates in the foreign matter reservoir,
2. The ink jet recording according to claim 1, further comprising: foreign matter opening / closing means for closing the foreign matter outlet when the foreign matter detection level of the foreign matter detector is lowered to a predetermined level while taking out the foreign matter from the foreign matter outlet. apparatus.   4. A foreign matter reservoir entrance opening / closing means that is disposed above the foreign matter reservoir and is closed when the foreign matter taking-off opening / closing means is opened to shut off the foreign matter reservoir and the ink storage portion. 2. An ink jet recording apparatus according to 1.   The ink jet recording apparatus according to claim 1, wherein a foreign material rising and shielding member having an upper side inclined is provided in the intermediate tank.

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