Source: https://patents.google.com/patent/JP4468192B2/en
Timestamp: 2020-02-20 03:15:00
Document Index: 748941661

Matched Legal Cases: ['art 121', 'art 132', 'art 134', 'art 121', 'art 134', 'art 124', 'art 111', 'art 133']

JP4468192B2 - Inkjet recording device - Google Patents
JP4468192B2
JP4468192B2 JP2005020312A JP2005020312A JP4468192B2 JP 4468192 B2 JP4468192 B2 JP 4468192B2 JP 2005020312 A JP2005020312 A JP 2005020312A JP 2005020312 A JP2005020312 A JP 2005020312A JP 4468192 B2 JP4468192 B2 JP 4468192B2
JP2005020312A
JP2006205528A (en
秀夫 深澤
2005-01-27 Application filed by キヤノン株式会社 filed Critical キヤノン株式会社
2005-01-27 Priority to JP2005020312A priority Critical patent/JP4468192B2/en
2006-08-10 Publication of JP2006205528A publication Critical patent/JP2006205528A/en
2010-05-26 Publication of JP4468192B2 publication Critical patent/JP4468192B2/en
The present invention is, for example, storing the ink supplied from the main tank in click is accommodated in the sub tank, to Louis inkjet recording apparatus to supply ink to the ejection head from the sub tank.
In a conventional ink jet recording apparatus, the inside of the nozzle having the discharge port of the recording head that discharges ink is maintained at a negative pressure, thereby causing an ink meniscus in the nozzle, ink leakage from the nozzle, and from the atmosphere to the inside of the nozzle. To prevent air from entering.
In this type of conventional ink jet recording apparatus, as one of the configurations for generating a meniscus at the discharge port of the recording head, a main tank in which ink is stored and ink supplied from the main tank are stored in the recording head. There is an ink supply device that includes a subtank for supplying ink to the printhead, the subtank is disposed vertically below the printhead, and supplies water from the subtank to the printhead by a water head difference between the subtank and the printhead. In the conventional ink supply apparatus, a so-called chicken feed system may be used as a simple configuration as a system for supplying ink from the main tank to the sub tank.
As a conventional chicken feed type ink supply apparatus, an ink supply tube is installed from a main tank by mounting a main tank, which is stored in an airtight and replaceable ink, in a tank mounting portion in an ink jet recording apparatus. A configuration is disclosed in which ink is supplied into the sub-tank via the (see Patent Document 1).
However, in the conventional ink supply device as disclosed in Patent Document 1, a spring-biased on-off valve that is opened and closed when the ink supply port of the main tank is installed in the ink jet recording apparatus is provided. This on-off valve may open due to an impact when the main tank falls, for example, and may cause ink leakage.
As a countermeasure against such ink leakage, as shown in FIG. 7, in a conventional chicken feed type ink supply apparatus 700, ink is stored in an airtight manner and is exchanged from a main tank 701 to a sub tank 702. Some have a supply base 705 provided with two hollow needles, an ink supply needle 703 for supplying water and an air introduction needle 704 for introducing air into the main tank 701 during gas-liquid exchange. .
In the main tank 701, the opening of the connecting portion connected to the supply base 705 is hermetically closed by a rubber plug 706. When the main tank 701 is connected to the supply base 705, the ink supply needle 703 and the air introduction needle 704 connect the rubber plug 706. The ink passes through and communicates with the main tank 701, supplies ink from the main tank 701 to the supply base 705 via these two needles, and supplies ink to the sub tank 702 from the supply base 705 via the ink supply tube 707. Is configured to do.
As described above, the rubber plug 706 having elasticity is provided at the connection portion of the main tank 701, so that even when the main tank 701 is pulled out from the ink supply needle 703 and the air introduction needle 704 on the supply base 705 side, Since the through hole is hermetically closed by the elasticity of the rubber plug 706, the sealing property of the connecting portion of the main tank 701 is ensured satisfactorily, and ink is prevented from scattering from the connecting portion when the main tank 701 is dropped. ing. The rubber plug 706 through which the ink supply needle 703 and the air introduction needle 704 are penetrated has a limit in increasing the inner diameter of these two hollow needles in order to prevent cracks from being generated and broken. In general, the inner diameter of the ink supply needle 703 and the air introduction needle 704 is about φ1.6 mm.
Further, Patent Document 2 discloses a chicken feed supply configuration in which a detachable and sealed main tank is communicated with a hollow tube at a connection portion to ensure a water head difference from a recording head.
Further, Patent Document 3 discloses a chicken feed configuration in which a plurality of communication pipes are provided in the ink supply of the first ink tank and the sealed second ink tank.
JP-A-3-247460 (FIG. 1) Japanese Patent Laid-Open No. 2002-234180 JP 2004-142442 A
By the way, as described above, the conventional chicken feed supply device that employs a configuration using an air introduction needle that is a hollow needle, when using a small diameter air introduction needle having an inner diameter of about 1.6 mm, is open to the atmosphere. In many cases, a meniscus due to ink is generated inside the introduction needle or at the lower end of the air introduction needle, and the state of the meniscus is uncertain. For this reason, in this conventional liquid supply device, the negative pressure inside the sealed main tank generated by the water head difference becomes smaller than the meniscus force, the ink in the main tank is not supplied to the sub tank, and the recording state by the discharge head is It sometimes got worse.
In the chicken feed type ink supply configuration of Patent Document 2, a specific configuration for realizing stable head maintenance is not disclosed.
The configuration of Patent Document 3 discloses a configuration in which a plurality of communication pipes are provided and the inner diameters of the communication paths are different in the ink supply of the first ink tank and the sealed second ink tank. However, the second ink tank is sealed with the first tank open to the atmosphere. Therefore, in order to maintain the water head difference, the plurality of communication pipes are each configured as a gas flow path, a liquid flow path, or the contents to be circulated depending on the ink supply conditions. Further, a spring member for generating a negative pressure is provided in the second ink tank. The ink liquid level varies, and the ink level is not always maintained at a fixed position.
As described above, in the conventional ink jet recording apparatus, the liquid level position (water level) of the ink stored in the sub tank is changed by changing the negative pressure in the main tank according to the remaining amount of ink in the main tank of the ink supply apparatus. ) Is variable and unstable.
Also, the ink supply device of the conventional ink jet recording apparatus has a variation in the amount of ink stored in the sub tank when the ink in the main tank runs out or when the main tank is removed for some reason. There is a problem that it is difficult to guarantee the time for continuous recording and the number of recording sheets.
Accordingly, the present invention provides an ink jet recording equipment which is capable of storing ensures stable ink surface position of the ink stored in the subtank is supplied from the main tank, the necessary quantity of ink in the sub tank The purpose is to do.
To achieve the above object, an ink jet recording apparatus according to the present invention the reservoir and a recording head for ejecting ink, a main tank containing the ink to be supplied to the recording head, the ink supplied from the main tank in the ink jet recording apparatus and a sub-tank capable of supplying prior type recording head, the sub tank, an ink supply path for supplying ink from the main tank, an air introduction passage for introducing air into the main tank The length of the air introduction path is shorter than the length of the ink supply path, the flow resistance of the air introduction path is smaller than the flow resistance of the ink supply path, and the air introduction path is An air introduction pin disposed on the tank side and having a first cross-sectional area, and a second larger than the first cross-sectional area disposed on the sub-tank side A thick pipe portion having a cross-sectional area, when the pressure due to the vertical head difference of the thick pipe portion is H, the flow resistance of the introduction pin is R, and the meniscus force of the introduction pin is M, H> M + R is satisfied .
As described above, according to the present invention, the liquid level position of the ink supplied from the main tank and stored in the sub tank can be kept constant, and a constant amount of ink can be stored stably in the sub tank.
FIG. 1 is an explanatory diagram for explaining the entire inkjet recording apparatus according to the present invention. It is the perspective view which removed a part of exterior.
As shown in FIG. 1, an ink jet recording apparatus 10 according to the present embodiment includes an ink supply unit that holds an attachable / detachable main tank 101, includes a sub tank 102, and is an ink supply unit that discharges ink to an ejection head. A unit 100, a recording head (not shown) that discharges ink supplied from the ink supply unit 100, and a carriage unit 300 that moves the recording head to a recording position; A recovery system unit 400 for recovering the ejection characteristics of the recording head and a frame unit 500 that supports these units are provided.
The ink supply unit 100 includes a tank holder 204 formed with a tank mounting portion on which a main tank 101 that is a replaceable sealed container is detachably mounted, a tank cover 202 that covers the tank mounting portion, and a sub tank 102. is doing.
As will be described in detail later, when the main tank 101 is mounted on the tank mounting portion, a sealing needle 113 provided in the cap member 115 constituting the connecting portion 106 of the main tank 101 is provided with a hollow needle provided on the sub tank 102 side. By being connected to the ink supply pin 131 and the air introduction pin 133, the ink stored in the main tank 101 is supplied to the sub tank 102. The sub tank 102 and the recording head mounted on the carriage unit 300 are connected by an ink supply tube 306 to form an ink supply path.
In the carriage unit 300, a carriage 301 on which a recording head is mounted is supported across a slide shaft 302 and a slide rail 303, and the driving force of the carriage motor 305 is transmitted via the driving belt 304. The recording head on the carriage 301 is moved toward the recording position 502.
The recovery system unit 400 includes a cap member, a suction pump, a blade for wiping ink, and the like that are brought into contact with the ejection port of the recording head to cover the ejection port portion in order to solve the problem of the recording head mounted on the carriage 300. However, since it is not directly related to the main part of the present invention, detailed description thereof is omitted.
The frame unit 500 of the inkjet recording apparatus 10 includes a protection plate 501 supported by the left and right side plates. The protective plate 501 has an opening at a recording position 502 by the recording head.
The carriage 300 transmits the driving force of the carriage motor 305 to the belt 304 while maintaining the posture by the slide shaft 302 and the slide rail 303, and moves the recording head toward the recording position 502 on the front surface of FIG. To do.
FIG. 2 shows a cross-sectional view of the ink supply unit 100 of the ink jet recording apparatus 10. FIG. 3 is a sectional view showing a state where the main tank and the subtan are separated.
As shown in FIGS. 2 and 3, the ink supply unit 100 is configured to supply ink by a so-called chicken feed method, and the main tank 101 in which the ink supplied to the recording head 350 that discharges the ink is stored in an airtight manner. And a sub tank 102 that is connected to the main tank 101 and stores the ink supplied from the main tank 101 and supplies the ink to the recording head 350.
The main tank 101 is detachably attached to the tank mounting portion of the tank holder 204, and can be replaced when the ink is consumed. The main tank 101 includes a tank main body 105 that forms an ink storage portion that stores ink, a connection portion 106 that is provided on the bottom surface of the tank main body 105 and is connected to the sub tank 102, and a cap member 115 that covers the connection portion 106. have.
The connection unit 106 airtightly closes the ink supply port 111 for supplying ink to the sub tank 102, the air introduction port 112 for introducing air from the sub tank, and the ink supply port 111 and the air introduction port 112, respectively. A sealing plug 113, a fixing member 114 for fixing the sealing plug 113, and a cap member 115 covering these members are provided, and the ink tank is sealed.
The sealing plug 113 is formed of an elastic material such as rubber, for example, and is penetrated in the thickness direction by an ink supply pin and an air introduction pin on the side of the sub tank 102, which will be described later, by attaching the main tank to the ink jet recording apparatus. The
The sub tank 102 is disposed in the middle of the flow path for supplying ink from the main tank 101 to the recording head 350, and is a single ink containing portion having an air opening 126.
The sub tank 102 supplies ink through an ink supply tube 306 to the ink supply pipe 123 for supplying ink from the main tank 101, an air introduction pipe 124 for introducing air into the main tank 101, and the recording head 350. And an air opening 126 that communicates with the atmosphere.
The ink supply pipe 123 includes an ink supply pin 131 that communicates with the ink supply port 111 of the main tank 101, and a connection pipe portion 132 that is a flow path connected to the ink supply pin 131. The air introduction pipe 124 has an air introduction pin 133 that communicates with the air introduction port 112 of the main tank 101, and a thick pipe portion 134 that is connected to the air introduction pin 133. The air introduction pipe 124 has a lower end extending into the sub tank 102 and is formed to be shorter than the length of the ink supply pipe 123.
The ink supply pipe 123 of this embodiment is composed of two members, the ink supply pin 131 and the connection pipe portion 132 connected to the ink supply pin 131, but may be a single continuous member. Similarly, the air introduction pipe 124 may be formed of a single continuous member.
The ink supply pin 131 and the air introduction pin 133 are hollow needles that are open at both ends, and are located on the main tank 101 side, and are integrally formed by insert molding on the upper part 121 of the sub tank 102 together with a caulking member for preventing the removal. ing. The ink supply pin 131 and the air introduction pin 133 are conically formed and closed at the upper ends so as to smoothly pass through the sealing plug 113 of the main tank 101, and ink or air is formed on the peripheral surface near the upper ends. An opening is provided to pass through. By exposing this opening in the main tank 101, ink and air flow paths are formed. The openings at the lower ends of the ink supply pins 205 and the air introduction pins 204 are connected to the respective flow paths formed by the connecting pipe part 132 and the thick pipe part 134 formed in the upper part 121 of the sub tank 203, respectively.
The flow path in the connecting pipe portion 132 is formed to be substantially equal to the inner diameter of the ink supply pin 131 that is a hollow needle.
Similarly, the flow path in the thick tube portion 134 is formed to be larger than the inner diameter of the air introduction pin 133 that is a hollow needle, and the inner diameter of the flow path, i.e., between the main tank and the sub tank, to the extent that the meniscus due to ink does not stretch. The cross-sectional area perpendicular to the air flow direction is increased. By adopting this configuration, the flow resistance of the air introduction pin 133 and the thick tube portion 134 is made smaller than the flow resistance of the ink supply pin 131 and the connecting tube portion 132. The lower end of the thick pipe portion 134 is configured to extend in the depth direction in the sub tank 102.
The air introduction pipe 124 formed by connecting the air introduction pin 133 and the thick pipe portion 134 constitutes a flow path for supplying air from the sub tank 102 to the main tank 101, and the lower end surface of the thick pipe portion 134 is The liquid level position (water level) 138 of the ink stored in the sub tank 102 becomes constant, and this liquid level position 138 is always kept constant. That is, the flow path in the thick pipe portion 134 functions to maintain the liquid level position.
In order to hold the liquid level at a stable position, it is necessary to secure the vertical length of the thick pipe portion 134 to a water head difference that exceeds the flow resistance of the air introduction pin 133 and the meniscus force.
For this reason, as described above, the air introduction pipe 124 is formed such that the cross-sectional area of the thick pipe portion 134 is large enough not to cause meniscus in the flow path of the thick pipe portion 134, and the vertical head of the thick pipe portion 134. When the pressure [mmAq] due to the difference is H, the flow resistance [mmAq] of the entire air introduction pin 133 is R, and the meniscus force [mmAq] of the air introduction pin 133 is M,
H> R + M Formula 1
Meet. As a result, the liquid level of the ink stored in the sub tank 102 can be kept constant and stable.
The meniscus force M [mmAq] is expressed by a surface tension formula,
M = 2γ · cos θ / r Equation 2
It becomes. However, (gamma) is surface tension, (theta) is a contact angle, r is the radius of the flow path in the air introduction pin 133. FIG.
Further, the channel resistance R [mmAq] of the entire air introduction pin 133 is expressed by the formula of the loss head.
R = 32 μLV / Cd 2 Formula 3
It becomes. Where μ is the viscosity coefficient, L is the length of the J-type flow path, V is the average flow velocity, C is the weight per unit volume of the fluid (ink), and d is the diameter of the flow path.
An operation in which gas-liquid exchange is performed between the main tank 101 and the sub tank 102 due to a water head difference generated in a part of the flow path formed by the ink supply pipe 123 and the air introduction pipe 124 by satisfying Expression 1 will be described.
FIG. 4 is a schematic diagram of a flow path formed by an ink supply pipe and an air introduction pipe for communicating the main tank and the sub tank. FIG. 5 is a cross-sectional view showing a state where the main tank is connected to the sub tank and the ink level in the sub tank is kept constant.
Since the inside of the main tank 101 is hermetically sealed, as shown in FIGS. 4 and 5, the distance from the lower end of the air introduction pin 133 to the liquid level in the main tank 101 corresponds to the height Hu of the U-shaped tube portion. The lower end portion of the connecting pipe portion 132 immersed in the ink in the sub tank 102 corresponds to the height Hd. And the space in the flow path of the thick pipe part 134 is equivalent to the height H, and the pressure which is the water head difference of this height H acts.
When gas-liquid exchange is performed to supply ink from the main tank 101 to the sub tank 102, the flow path resistance due to the height (H + Hu + Hd) is applied to the ink in all the flow paths of the J-shaped tube shown in FIG. Become. This is because, during the gas-liquid exchange, the ink filling the thick pipe portion 134 flows toward the air introduction pin 133, and the ink in the flow path of the air introduction pin 133 is recirculated into the main tank 101 and the ink supply pin 131. This is because the ink is supplied to the sub tank 102 from this flow path.
When the meniscus is stretched and balanced at the upper end of the flow path of the J-shaped pipe shown in FIG. 4, that is, the lower end of the air introduction pipe 124, there is no flow velocity, so the flow resistance R = 0. In such a state where there is no flow velocity, ink does not flow from the main tank 101 to the sub tank 102, and at this time, H = M.
As the recording operation of the recording head 350 consumes the ink stored in the sub tank 102 and the liquid level position 138 descends, the air enters the flow path of the thick tube portion 134 and the lower end of the air introduction pin 133. To reach. When the lower end portion of the air introduction pin 133 is at atmospheric pressure, the balance of H = M is broken, and the relationship of the above-described formula 1 is satisfied, and a flow velocity is generated, so that the main tank 101 and the sub tank 102 Gas-liquid exchange takes place between them.
Further, in the experiment, the air introduction tube 124 is configured by using the ink having a surface tension of about 2 [mN / m], and the thick tube portion 134 is connected to the air introduction pin 133 having an inner diameter of about 1.6 mm. In this case, the configuration necessary for operating the water level holding function described above requires an inner diameter of about 8 mm so that no meniscus is stretched in the flow path of the thick pipe portion 134, and the vertical length of the thick pipe portion 134. When the (water head difference) was formed to be 10 mm or more, the liquid level position 138 of the ink stored in the sub tank 102 was stably maintained.
In addition, when the thick pipe part has the same inner diameter as described above and the length in the vertical direction is less than 10 mm, the meniscus force by the air introduction pin is balanced with the water head difference by the thick pipe part, The introduction of air into the main tank 101 was stopped, and the liquid level did not rise to the lower end of the air introduction pin.
The liquid level position 138 maintained constant in the sub tank 102 is positioned below the position of the discharge port of the recording head 350 in the vertical direction, and the discharge port is caused by a water head difference between the discharge port and the liquid level position 138. Thus, a desired meniscus is generated by the ink, and the ink is ejected favorably.
In addition, an ink discharge unit 140 for supplying the stored ink to the recording head 350 is provided at one end of the sub tank 102. The ink discharge unit 140 has an ink discharge pipe 141 having an ink discharge port 142 formed at the lower end. A tube insertion port 143 to which an ink supply tube 306 that supplies ink to the recording head 350 is connected is formed at the upper end of the ink discharge tube 141, and the upper end portion is supported by the upper portion 121 of the sub tank 102. Therefore, the ink supplied from the main tank 101 and temporarily stored in the sub tank 102 is discharged from the ink discharge port 142 and supplied to the recording head 350 on the carriage 301 via the ink supply tube 306. .
Further, an inclined surface that gradually increases the depth in the vertical direction from the ink supply pipe 123 side to the ink discharge portion 140 side is formed on the bottom surface portion of the sub tank 102, and the ink discharge port 142 is the deepest portion at the lowest position. The ink stored in the sub-tank 102 is smoothly discharged from the ink discharge port 142, so that the ink can be used up satisfactorily. The air introduction tube 124 is provided at a position closer to the ink discharge port 142 than the ink supply tube 123.
In recent years, color materials composed of pigments have been used as inks. However, if recording is performed while the pigment component of the ink settles in the ink and is separated, there is a risk that a density difference will occur in the recorded image. There is. For this reason, in the ink supply unit according to the present invention, for the purpose of stirring the entire ink stored in the sub tank 102, the flow path of the connecting pipe portion 132 forming the ink supply pipe 123 from the main tank 101, and the recording head 350 are used. The ink discharge port 140 for supplying ink to the ink discharge port 142 is disposed at a position separated from the ink discharge port 140, and an inclined surface 145 is formed on the bottom surface of the sub tank 102. On the upstream side of the inclined surface 145, By providing the flow path of the connecting pipe portion 132, the settled pigment component can be sufficiently stirred as a whole, and good recording can be realized without causing a difference in ink concentration. Has been.
Further, a projecting portion 147 is integrally formed on the top surface of the upper portion 121 of the sub tank 102 between the ink supply pin 131 and the air introduction pin 133. An air passage formed along the vertical direction is formed in the protruding portion 147, and an air opening 126 is formed at the upper end of the air passage. Since the air release port of the sub tank is located at the tip of the protruding portion 147, the protruding portion serves as a wall between the ink supply pin and the air introducing pin, and the ink leaked even when ink leakage occurs The area where the spreads is narrowed. Further, the thick pipe portion 134 of the air introduction pipe 124 is provided at a position adjacent to the atmosphere opening 126.
In addition, two ink detection plates 148 that are electrically conductive are provided at an upper portion 121 of the sub tank 102 with a gap therebetween. The lower end portions of these ink detection plates 148 extend slightly below the liquid level position 138 kept constant in the sub tank 102 and are immersed in the ink. The upper end of the ink detection plate 148 exposed to the outside of the sub tank 102 is electrically connected to a control circuit unit (not shown) included in the ink jet recording apparatus.
When the ink in the main tank 101 runs out of ink, the ink supply unit decreases the ink remaining amount in the sub tank 102 where the ink supply from the main tank 101 is stopped, and the ink level 138 in the sub tank 102 is lowered. To do. As the ink level 138 in the sub-tank 102 descends in this way, the two ink detection plates 148 have their lower ends immersed in the ink come out of the ink and are exposed to the air. As a result, the control circuit unit detects this state and the lowering of the liquid level position 138 is detected.
Further, the ink storage part of the sub tank 102 is for storing ink in the upper space 151 and the lower space 152 with respect to the lower end (liquid level position 138) of the flow path of the thick pipe part 124 of the air introduction pipe 124. Has different functions.
In the upper space 260, when the gas in the sealed main tank 101 undergoes a volume change with the temperature change in the surrounding environment, the ink in the main tank 101 exceeds the ink consumption of the recording head 350 in the sub tank 102. When pushed out, it functions as an ink containing portion for temporarily containing the excessively supplied ink.
If the temperature change is caused by normal use, the ink that has excessively flowed out of the main tank 101 uses the upper space 151 of the sub tank 102 as an ink container, and when the temperature change returns to the original state, the main tank 101 As a result, the ink that has flowed into the sub tank 102 is returned to the main tank 101 again. When an excessive temperature change exceeding normal use occurs, the ink that has flowed from the main tank 101 to the sub tank 102 fills the upper space 151 and then discharges the ink from the air opening 126.
A lower space 152 of the sub tank 102 is an ink storage unit for storing a certain amount of ink in the sub tank 102. After the ink in the main tank 101 is exhausted, the supply of ink from the main tank 101 is stopped, Even when the main tank 101 is detached from the tank mounting portion, it functions as an ink containing portion for enabling continuous recording.
When the ink in the main tank 101 runs out of ink, the ink supply unit stops supplying ink from the main tank 101, so that the liquid level position in the sub tank 102 gradually increases as the recording head 350 discharges ink. Then, the lower end of the ink detection plate 148 is exposed from the ink to the air.
The control circuit unit detects that the liquid level position 138 has been lowered by the ink detection plate 148, and issues a warning such as a display indicating that the ink in the main tank 101 has run out, and prompts the user to replace the main tank 101. Prompt. However, the ink jet recording apparatus has a configuration in which the control circuit unit electrically detects the liquid level position 138 in the sub tank 102 and does not transmit or receive any electrical signal from the main tank 101 side. Even if 101 is removed from the apparatus, the control system of the ink jet recording apparatus is not affected.
For this reason, the ink jet recording apparatus continues the recording operation using a certain amount of ink stored in the space below the liquid surface position 138 even when the main tank 101 is removed from the tank mounting portion. Since the recording operation can be continued until the liquid level reaches the ink discharge port 142 which is the lowest point of the sub-tank 102, it is possible to prevent a recording failure from being caused by the ink being not ejected from the recording head 350 during the recording operation. .
When the main tank is removed, there is a case where the recording of the ink jet recording apparatus is suddenly interrupted due to running out of ink. If continuous printing or large format printing is being performed, printing may be interrupted during recording on one sheet. Even in such a case, the flow resistance of the ink supply pipe or the air introduction pipe of the sub-tank and the ink amount equal to the amount capable of continuing a predetermined recording with a predetermined length are secured. The water level holding position can be determined. For example, the time required to replace the main tank after the main tank is removed is determined in advance, and the water level holding position is determined so that the recording operation is continued during that time. There is a way to decide to keep. Alternatively, after the main tank is removed, a predetermined amount of ink that can continue to be recorded may be determined, and the water level holding position of the sub tank may be determined.
As described above, according to the ink supply unit of the present embodiment, the thick tube portion 134 of the air introduction tube 124 is formed to have a size that does not cause a meniscus in the flow path of the large tube portion 134. As a result, a difference in flow resistance between the air introduction pin 133 and the thick pipe portion 134 is always generated, and the liquid level position 138 of the ink stored in the sub tank 102 can be kept constant. In addition, a desired meniscus can be generated in the recording head 350 by the water head difference between the liquid level position 138 kept constant in the sub tank 102 and the ejection port of the recording head 350.
That is, in the ink supply unit of the ink jet recording apparatus of the present embodiment, the chicken feed method is adopted as the ink supply method from the main tank 101 to the sub tank 102, and a relatively small-diameter hollow needle is used as the air introduction pin 133. Even in the configuration, the desired liquid level position 138 is kept constant without being affected by the meniscus that is more likely to occur as the hollow needle becomes thinner, and the supply of ink from the main tank 101 to the sub tank 102 is stagnant. Thus, the ink can be smoothly supplied to the recording head 350. Therefore, according to this ink supply unit, the water head difference for maintaining the meniscus in the nozzles of the recording head 350 is stabilized, and the reliability of the ink supply operation to the recording head 350 can be improved.
Further, by determining the liquid level holding position 138 in the sub tank 102 as a position that secures a predetermined amount of ink that can be continuously recorded, after the ink in the main tank 101 runs out, Even when the 101 is removed from the sub tank 102, a certain amount of ink is stored in the sub tank 102. Therefore, until a certain amount of ink is consumed, a certain amount of time or a certain number of sheets of recording paper is used. Recording can be continued. According to this ink supply unit, the single sub tank 102 continuously receives the upper space 151 for storing the ink that has flowed out of the main tank 101 due to a temperature change, and after the ink in the main tank 101 has run out. By serving as a lower space 152 for storing a certain amount of ink for performing a recording operation, a plurality of functions as an ink jet recording apparatus can be improved with a single ink storage unit. Miniaturization can be realized.
Next, an ink supply unit according to another embodiment will be described with reference to the drawings. The ink supply units of the other embodiments are different only in the configuration in which the main tank 101 and the sub tank 102 are arranged apart from each other, and the basic configuration is almost the same as that of the above-described embodiment, so the same members are the same. The reference numerals are attached and the description is omitted.
As shown in FIG. 6, in the sub tank 102 provided in the ink supply unit of another embodiment, the lower end of the ink supply pin 131 and the upper end of the connecting pipe portion 132 are connected via the ink supply tube 161. Similarly, in the sub tank 102, the lower end of the air introduction pin 133 and the upper end of the thick pipe portion 134 are connected via an air introduction tube 162. The inner diameters of the ink supply tube 161 and the air introduction tube 162 are formed substantially equal to the inner diameters of the ink supply pin 131 and the air introduction pin 133.
When the ink supply unit configured in this manner supplies ink from the main tank 101 into the sub tank 102, the ink supply unit passes through the ink supply tube 161 and the air introduction tube 162 in the same manner as the ink behavior in the above-described embodiment. Liquid exchange is performed, and the liquid level position of the ink stored in the sub tank 102 is kept constant.
According to the ink supply unit of the present embodiment, the main tank 101 and the sub tank 102 are connected via the ink supply tube 161 and the air introduction tube 162, whereby the main tank 101 and the sub tank 102 in the ink jet recording apparatus are connected. The degree of freedom of the arrangement position can be improved.
In each of the above-described embodiments, the thick tube portion 134 of the air introduction tube 124 that functions to maintain the water level is formed in a cylindrical shape. However, the present invention is not limited to the cylindrical shape, and a meniscus formed of ink in the thick tube portion. For example, a conical shape in which the inner diameter gradually changes along the length direction or a configuration in which the inner wall surface of the flow path is inclined with respect to the vertical direction may be employed. The effect of keeping the constant liquid level position 138 stably can be obtained similarly.
In the ink supply unit of the above-described embodiment, the air introduction tube 124 is configured by connecting the air introduction pin 133 and the thick tube portion 134 having different flow passage inner diameters. Even if a straight tubular air introduction tube that does not change is used, the above-described effects can be obtained similarly. In the case of this configuration, the air introduction pipe is formed in a transverse area where no meniscus is generated over the entire length, the head difference in the vertical direction of the entire air introduction pipe is H, and the meniscus force due to the transverse area of the ink supply pipe is M. When the flow path resistance of the ink supply pipe is R, the above-described formula 1 is satisfied.
In addition, among the two flow paths that can communicate with the main tank provided in the sub tank, the bottom surface in the sub tank opening of the air introduction flow path is formed into an oblique shape so that the end surface has a sufficiently large size so that no meniscus is formed. Also good.
1 is a partially exploded perspective view illustrating an entire inkjet recording apparatus according to an embodiment. It is sectional drawing which shows the ink supply unit which concerns on embodiment. It is sectional drawing which shows the state from which the main tank and the subtank are isolate | separated. It is a schematic diagram for demonstrating the operation | movement in which gas-liquid exchange is performed between a main tank and a sub tank. FIG. 6 is a cross-sectional view showing a state where the main tank is connected to the sub tank and the liquid level position of the ink in the sub tank is kept constant. It is sectional drawing which shows the ink supply unit which concerns on other embodiment. It is sectional drawing which shows an example of the conventional ink supply apparatus typically.
DESCRIPTION OF SYMBOLS 10 Inkjet recording device 100 Ink supply unit 101 Main tank 102 Sub tank 106 Connection part 111 Ink supply port 112 Air introduction port 123 Ink supply tube 124 Air introduction tube 126 Atmospheric release port 131 Ink supply pin 132 Connecting tube part 133 Air introduction pin 134 Thick Tube unit 140 Ink discharge unit 142 Ink discharge port 350 Recording head
A recording head for ejecting ink;
A main tank for storing ink to be supplied to the recording head;
In the ink jet recording apparatus provided with the sub tank and, that can be supplied to pre-type recording head storing the ink supplied from the main tank,
Said sub tank, e Bei an ink supply path for supplying ink from the main tank, and an air introduction passage for introducing air into the main tank,
The length of the air introduction path is shorter than the length of the ink supply path,
The flow resistance of the air introduction path is smaller than the flow resistance of the ink supply path,
The air introduction path includes an air introduction pin disposed on the main tank side and having a first cross-sectional area, and a thick pipe portion disposed on the sub-tank side and having a second cross-sectional area larger than the first cross-sectional area; And H> M + R, where H is the pressure due to the head differential in the vertical direction of the large pipe, R is the flow resistance of the introduction pin, and M is the meniscus force of the introduction pin. An ink jet recording apparatus.
2. The ink jet recording apparatus according to claim 1, wherein each of the ink supply path and the air introduction path includes two members .
The sub tank includes an ink discharging portion for supplying ink to said recording head, according to claim 1 wherein the air introduction path and which are located at a position close to the ink discharge portion than the ink introduction path or 2. An ink jet recording apparatus according to 2.
4. The ink jet recording apparatus according to claim 3, wherein an inclined surface having a depth in a vertical direction that increases from the ink supply path toward the ink discharge portion is formed on a bottom surface portion of the sub tank .
Lower end position of the air guide entrance road of the subtank is a predetermined liquid level holding position, the ink holding amount in the sub-tank to be secured by the liquid level holding position, fixed to a predetermined recording 2. The ink jet recording apparatus according to claim 1, wherein the ink is a constant amount of ink that can be continued.
6. The ink jet recording apparatus according to claim 5, wherein the predetermined amount of ink is an amount capable of continuous recording for a predetermined time.
6. The ink jet recording apparatus according to claim 5, wherein the predetermined amount of ink is a predetermined number of recording sheets and an amount capable of continuous recording.
JP2005020312A 2005-01-27 2005-01-27 Inkjet recording device Active JP4468192B2 (en)
JP2005020312A JP4468192B2 (en) 2005-01-27 2005-01-27 Inkjet recording device
US11/338,076 US7465044B2 (en) 2005-01-27 2006-01-24 Ink jet recording apparatus and liquid supply apparatus
US12/269,882 US8162454B2 (en) 2005-01-27 2008-11-12 Ink jet recording apparatus and liquid supply apparatus
JP2006205528A JP2006205528A (en) 2006-08-10
JP4468192B2 true JP4468192B2 (en) 2010-05-26
ID=36696329
JP2005020312A Active JP4468192B2 (en) 2005-01-27 2005-01-27 Inkjet recording device
US (2) US7465044B2 (en)
JP (1) JP4468192B2 (en)
JP4720876B2 (en) 2008-08-28 2011-07-13 ブラザー工業株式会社 Inkjet recording device
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JP6047960B2 (en) * 2012-07-09 2016-12-21 株式会社リコー Image forming apparatus
JP2018140608A (en) 2017-02-28 2018-09-13 ブラザー工業株式会社 Liquid supply device and image recording device
JP2018140609A (en) 2017-02-28 2018-09-13 ブラザー工業株式会社 Image recording device
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JP4125206B2 (en) 2002-09-30 2008-07-30 キヤノン株式会社 Ink supply system
CN1261304C (en) * 2002-09-30 2006-06-28 佳能株式会社 Ink supply system and its filling and adding container, ink-jet recording device and cartriage
2005-01-27 JP JP2005020312A patent/JP4468192B2/en active Active
2006-01-24 US US11/338,076 patent/US7465044B2/en not_active Expired - Fee Related
2008-11-12 US US12/269,882 patent/US8162454B2/en active Active
JP2006205528A (en) 2006-08-10
US20060164478A1 (en) 2006-07-27
US8162454B2 (en) 2012-04-24
US7465044B2 (en) 2008-12-16
US20090102898A1 (en) 2009-04-23
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