1. Technical Field
The present invention relates a liquid storing container suitable for detecting an ink residual quantity or detecting a pressurized/unpressurized state in an ink. cartridge.
2. Related Art
An ink cartridge having an ink residual quantity detecting function is disclosed in JP-A-2006-160371. The ink residual quantity is detected by providing a movement member, which moves according to a liquid surface level, in an ink storing unit, applying vibration to a concave portion (sensor cavity) which forms a closed space in cooperation with a wall surface of the movement member by a piezoelectric element and detecting the state of free vibrations.
In JP-A-2006-160371, a deformable ink pack is provided in a casing of the ink cartridge on the upstream side of the ink storing unit. A pressurized fluid, for example, air is introduced into the vicinity of the ink pack provided in the casing of the ink cartridge, the ink pack is pressurized by the air, and the ink in the ink pack is discharged. Accordingly, if the ink residual quantity of the ink pack is reduced, the ink pressure applied from the ink pack to the liquid storing unit is also reduced.
As the detection of the ink residual quantity, the movement member which is displaced according to the liquid pressure of the ink storing unit is provided and the ink end is detected on the basis of the output from the piezoelectric element when the sensor cavity becomes the closed space by the movement member by reducing the liquid pressure from the ink pack.
Meanwhile, as a method of supplying an ink of an ink cartridge, a method of directly supplying air into the inside of an ink containing unit is considered. In such an ink cartridge, an ink detecting device needs to be mounted, but, if the ink containing unit of this method and the ink residual quantity detecting function of JP-A-2006-160371 are combined, an air pressure continuously acts on the ink storing unit instead of the ink pressure if the pressurization due to air is continued although the ink of the ink containing unit runs out. Accordingly, since the movement member of the ink storing unit is not displaced, the method of detecting the ink end according to the position of the movement member cannot be employed.
As another pressurizing method, the ink cartridge is used as a sub tank and is used in combination with a high-capacity main tank connected to the sub tank. In this case, by the ink pressure applied from the main tank, the ink pressurized and supplied from the ink cartridge which is the sub tank. Even in the ink cartridge which is the sub tank, the detection of a pressurized/unpressurized state of the ink is required as described above.
An advantage of some aspects of the invention is that it provides a liquid storing container capable of detecting a pressurized/unpressurized state to a liquid containing region or detecting a liquid residual quantity even when a pressurizing method of introducing a pressurized fluid into the liquid containing region is employed.
According to an aspect of the invention, there is provided a liquid storing container including: a liquid containing unit which discharges a liquid by introducing a pressurized fluid into a region, in which the liquid is stored; a liquid lead-out port which supplies the liquid from the liquid containing unit to a liquid consumption device; and a detecting device which is provided between the liquid containing unit and the liquid lead-out port, wherein the detecting device includes a liquid storing unit which is provided between the liquid containing unit and the liquid lead-out port; a piezoelectric element which applies vibration to a sensor cavity for receiving the liquid in communication with the liquid storing unit and detects a state of free vibration due to the vibration; and a movement member which is displaced according to a pressurized state of the liquid storing unit at a position facing the sensor cavity.
In the aspect of the invention, the liquid from the liquid containing unit is pressurized and discharged by introducing the pressurized fluid into the region in which the liquid of the liquid containing unit is received. Accordingly, after all the liquid in the liquid containing unit is discharged to the liquid storing unit, the pressurized fluid is introduced from the liquid containing unit to the liquid storing unit, which is different from JP-A-2006-160371. If the liquid is introduced from the liquid containing unit to the movement member disposed in the liquid storing unit and the pressurized fluid is introduced from the liquid containing unit by the liquid pressure, the pressurized fluid pressure is applied. Accordingly, if the liquid containing unit is pressurized, the movement member is separated from the sensor cavity and is not displaced even when the pressure is changed from the liquid pressure to the fluid pressure, which is different from JP-A-2006-160371. If the liquid containing unit is not pressurized, the movement member is displaced to a position of the sensor cavity side which is different from the above-described position.
In the aspect of the invention, by the piezoelectric element which applies the vibration to the sensor cavity for containing the liquid in communication with the liquid storing unit and becomes the state of the free vibration due to the vibration, it is possible to detect the liquid residual quantity on the basis of a difference in the pressurized medium regardless of the movement member or detect the pressurized state or the unpressurized state on the basis of the position of the movement member.
For example, the pressurized fluid is different from the liquid to be tested. In this case, the piezoelectric element outputs different signals depending on whether or not a medium between the sensor cavity and the movement member is the liquid, at the time of pressurizing the liquid containing unit. The different signals are frequencies of free vibration or amplitudes of free vibration. One surface of the movement member may close the sensor cavity at the time of unpressurizing the liquid containing unit. In this case, the piezoelectric element may output the different signals at the time of pressuring and unpressurizing the liquid containing unit. The different signals are frequencies of free vibration or amplitudes of free vibration. The pressurization and the unpressurization of the liquid containing unit may be detected on the basis of a combination of the frequencies and amplitudes of the free vibration output from the piezoelectric element.
If the pressurized fluid is different from the liquid to be tested, the liquid residual quantity can be detected by the medium acting on the movement member and the pressurized/unpressurized state can be detected on the basis of the displacement of the movement member. In this case, the representative example of the pressurized fluid is air.
In another aspect of the invention, the pressurized fluid may be the liquid to be tested. In this example, for example, an ink cartridge is used as a sub tank and is used together with a high-capacity main tank connected to the sub tank. In this case, the ink is pressurized and supplied from the ink cartridge which is the sub tank, by the ink pressure supplied from the main tank.
Even in this case, one surface of the movement member closes the sensor cavity at the time of unpressurizing the liquid containing unit, and the piezoelectric element outputs different signals at the time of pressurizing and unpressurizing the liquid containing unit. Accordingly, it is possible to detect the pressurized/unpressurized state of the liquid containing unit of the ink cartridge used as the sub tank. The different signals are the amplitudes of the free vibration. The pressurization and the unpressurization of the liquid containing unit may be detected on the basis of a combination of the frequencies and amplitudes of the free vibration output from the piezoelectric element.
In the aspect of the invention, the liquid storing unit may be configured by sealing an opening formed in the upper surface thereof by a film which is deformable according to the pressurized state, and the piezoelectric element may be disposed below the liquid storing unit.
Accordingly, the liquid storing unit is deformed by the film deformed according to the pressure of the liquid or the pressurized fluid in the liquid storing unit, a liquid-tight space can be readily formed by the film, and liquid leakage or liquid evaporation can be prevented by a simple structure, compared with mechanical seal.
In the aspect of the invention, the movement member may be moved by the deformation of the film corresponding to the variation in pressurized state of the liquid storing unit and the movement member may be preferably adhered to the film.
Accordingly, since the movement member is displaced by the pressurization/unpressurization, the output waveform of the piezoelectric element can vary and the pressurized/unpressurized state can be detected.
In the aspect of the invention, the movement member may be urged by an urging member in a direction in which the piezoelectric element is disposed.
By adjusting the urging force of the urging member, a time point when the movement member is displaced and the displacement amount are adjusted in correspondence with a variation in pressurizing force such that the pressurized/unpressurized state can be detected with certainty.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Next, the embodiments of the invention will be described. The following embodiments are not limit the contents of the invention described in claims and all the configurations described in the present embodiment are not necessary for means to solve the invention.
As a condition of the invention, at least two of the following three states need to be distinguished by the output of a piezoelectric element.
The ink storing unit 4 shown in
The state A of
However, in the invention, the ink is the ink pack is not used, the pressurized fluid is introduced into the ink containing unit and the ink is forcedly fed. Accordingly, although the ink of the ink containing unit runs out, the pressurized fluid is introduced into the ink storing unit 4, that is, the fluid is introduced into the ink containing unit, so as to pressurize the inside of the ink containing unit, and the fluid is discharged to the ink storing unit. Thus, the state A of
The state B of
The state C of
The characteristics of the output waveforms of
The characteristics shown in Table is exemplary and, if the movement member attached with a channel according to the below-described embodiment is used, the frequency may be reversed like frequency A1<frequency B1 or the amplitudes AH, BH and CH may be reversed by the change of the frequency of the excitation waveform to the piezoelectric element, and the states A to C can be distinguished by at least the amplitude (AH<CH<BH in the data of Table) of the free vibration. The states A to C can be discriminated by a combination of the amplitude and the frequency. That is, even when the frequencies A1 and C1 cannot be discriminated in the data of Table, the state A or the state C can be discriminated by comparing the amplitudes AH and CH.
In the example of
In the example of
Accordingly, in the ink cartridge of
In the example of
In the example of
As shown in
As shown in
As shown in
The recording head 20 which is provided on the lower surface of the carriage 15 includes a plurality of nozzles (not shown) for ejecting the ink as the liquid and discharges ink droplets onto a print medium such as recording paper so as to perform the recording of print data such as images or characters. The valve units 21 are mounted on the carriage 15 and the ink which is temporarily stored is supplied to the recording head 20 in a state in which the pressure is adjusted.
In the present embodiment, the valve units 21 can individually supply two inks per one valve unit to the recording head 20 in the state in which the pressure is adjusted. In the present embodiment, the total number of valve units 21 is three and the valve units correspond to six ink colors (black, yellow, magenta, cyan, light magenta, and light cyan).
A platen (not shown) is provided below the recording head 20 and this platen supports the recording medium as a target which is transported in a sub scan direction perpendicular to the main scan direction by a sheet transportation unit (not shown).
The ink cartridges 23 shown in
As shown in
The ink detecting unit casing 133 has an ink lead-out member 109 into which an ink supply needle (liquid lead-out needle) of a cartridge mounting portion is inserted. The ink lead-out member 109 corresponds to the ink lead-out port 127 of
The pressurizing member 133b fits an engagement shaft 152 protruding on the outer circumference of the ink detecting unit casing main body 133a into a hole 151a of a locking piece 151 protruding from a base end, is rotatably connected to the ink detecting unit casing main body 133a, and is fixed so as to pressurize (energize) the movement member 300 to the ink detecting unit casing main body 133a with the sealing film 156 interposed therebetween by connecting the front end thereof to the ink detecting unit casing main body 133a by a spring 153 as an urging member.
A channel opening/closing mechanism 155 for opening the channel when the ink supply needle of the cartridge mounting portion is inserted is mounted in the ink lead-out member 109. The channel opening/closing mechanism 155 includes a cylindrical seal member 155a fixed to the ink lead-out member 109, a valve body 155b for maintaining the channel in a closed state by seating the valve body in the seal member 155a, and a spring member 155c for urging the valve body 155b to be seated in the seal member 155a.
The opening of the ink lead-out member 109 in which the channel opening/closing mechanism 155 is mounted is sealed by the sealing film 157 (see
When the ink cartridge 23 (see
As shown in
The sensor chip 132 is a piezoelectric detecting unit fixed to the rear surface of the ink detecting unit casing main body 133a such that vibration is applied to the sensor cavity 132A as a detecting space described in
The piezoelectric element 132C applies the vibration to the sensor cavity 132A so as to output a residual vibration waveform due to the vibration. The printer can detect the output signal and determine the ink end. As the material of the piezoelectric layer, zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), a piezoelectric film without lead or the like may be used.
The sensor chip 132 is integrally adhered to the sensor base 141 by an adhesive layer 132D by seating the lower surface of the chip main body on the central portion of the upper surface of the sensor base 141 and the sensor base 141 and the sensor chip 132 are simultaneously sealed by the adhesive layer 132D.
In the ink storing unit 200, an ink inlet 202 as a liquid inlet and an ink outlet 204 as a liquid outlet are formed. The ink inlet 202 communicates with the connection needle 111a shown in
In the cross section of a peripheral wall 208 partitioning the ink storing unit 200, a welding rib 208A is formed. The sealing film 156 (see
In the central portion of the ink storing unit 200, an opening 210 facing the sensor base 141 shown in
Directions along the orthogonal two axes having an intersection at the center of the ink storing unit 200 (the center of the circular pressure-receiving plate 31) are defined an X direction (first direction) and a Y direction (second direction).
In the movement member 300, two shafts 320 and 320 extending from the pressure-receiving plate 310 toward the both ends of the Y direction of
The upstream member 330 has protrusion members 332 and 334 protruding in the direction parallel with the Y direction in
The upstream member 330 has a first groove channel 336 as a first channel communicating with an end opening 336A of the X direction and extending in the X direction. The inner end of the first groove channel 336 communicates with a first through-hole 313 as the first channel formed in the pressure-receiving plate 310. A second groove channel 314 as the first channel is formed in the upper end surface 312 of the pressure-receiving plate 310, and the first through-hole 313 and a second through-hole 315 as the first channel are formed in the pressure-receiving plate 310 toward the second groove channel 314. The second groove channel 314 extends perpendicular to the X and Y directions, the first through-hole 313 existing on the X axis and the second through-hole 315 existing on the Y axis communicate with each other.
A third height reference surface 342 of the rear surface of the downstream member 340 functions as the first seal surface and the third height reference surface.
The downstream member 340 has a third groove channel 344 as a second channel formed in the third height reference surface 342 as the first seal surface. The inner end of the third groove channel 344 communicates with a third through-hole 316 as the second channel formed in the pressure-receiving plate 310. In addition, a fourth groove channel 317 as the second channel is formed in the upper end surface 312 of the pressure-receiving plate 310, and the third through-hole 316 and a fourth through-hole 318 as the second channel are formed in the pressure-receiving plate 310 so as to face the fourth groove channel 317. The fourth groove channel 317 extends perpendicular to the X and Y directions, and the third through-hole 316 existing on the X axis and the fourth through-hole 318 existing on the Y axis communicate with each other.
Since the upper end surface 312 of the pressure-receiving plate 310 is welded into the sealing film 156 as the diaphragm, the second groove channel 314 and the fourth groove channel 317 are sealed in a liquid-tight manner by the sealing film 156 as the diaphragm. As shown in
The first groove channel 336, the second groove channel 314, the first through-hole 313, and the second through-hole 315 formed in the upstream member 330 and the pressure-receiving plate 310 are collectively called the first channel. Similarly, the third groove channel 344, the fourth groove channel 317, the third through-hole 316 and the fourth through-hole 318 formed in the downstream member 340 and the pressure-receiving plate 310 are collectively called the second channel. The first channel communicates with the first through-through 141A as a supply path formed in the sensor base 141 shown in
In an initial stage in which the ink is introduced into the ink storing unit 200, the first channel and the second channel are formed and the ink flows in the first channel, the first through-hole 141A, the sensor cavity 132A (see
The positioning structure of the movement member 300 will be described with reference to
The diameter of the shaft 320 of the pressure-receiving plate 310 is slightly smaller than the dimension D1. Accordingly, the positioning of the movement member 300 in the X direction shown in
In order to position the movement member 300 in the Y direction, facing members 234 and 236 facing the semi-spherical surfaces 322 which are front ends of the two shafts 320 protruding from the pressure-receiving plate 310 are provided in the ink storing unit 200. In the ink storing unit 200, as shown in
The inner side surface 232 is the peripheral surface and the facing members 234 and 236 formed in the portions thereof are formed of the flat surfaces having a predetermined width W in the X direction of
Since the facing members 234 and 236 have the width W and are the flat surfaces, the distance between the two facing members 234 and 236 is constant. If there is a slight difference between the dimension D1 in the minimum gap between the first bearing 220 and the second bearing 224 and the diameter of the shaft 320, the movement member 300 is displaced in the X direction. However, within the range of the width W, the deviation in the Y direction is in a predetermined range.
Since the semi-spherical surfaces 322 which are the front ends of the two shafts 320 have the curved shape, for example, the semi-spherical surface, the semi-spherical surfaces are in point contact with the facing members 234 and 236. Accordingly, although the movement member 300 is displaced while the semi-spherical surfaces 322 which are the front ends of the two shafts 320 of the pressure-receiving plate in contact with the facing members 324 and 326, friction resistance is significantly low. Thus, the movement member 300 is not prevented from being displaced according to the ink pressure or the pressurized fluid pressure in the ink storing unit 200.
The center of the movement member 300 is positioned so as to be substantially equal to the intersection of the orthogonal two axes X and Y, which is the center of the ink storing unit 200. Accordingly, the positional precision of the movement member 300 relative to the ink storing unit 200 is improved. The improvement of the positional precision is very important in the charging of the ink in the sensor cavity 132A in an initial stage in which the ink is introduced into the ink storing unit 200 and that reason will be described later.
Next, the positioning of the height direction of the movement member 300 will be described. As described above, as shown in
As shown in
The third height reference surface 342 of the rear surface portion of the downstream member 340 of the movement member 300 functions as the first seal surface and is in contact with the third height reference surface of the ink storing unit 200 and the second seal surface at the initial stage in which the ink is introduced into the ink storing unit 200. Accordingly, the fourth groove channel 317 of the downstream member 340 of the movement member 300 is sealed. The sealing of the fourth groove channel 317 of the downstream member 340 is very important in the charging of the ink in the sensor cavity 132A by the suction from the ink lead-out port 127 and the capillary phenomenon in the initial stage. That reason is because, if the seal property of the first height reference surface 332A, the second height reference surface 334A and the third height reference surface 342 forming the first seal surface, and the first height reference surface 240, the second height reference surface 242 and the third height reference surface 244 forming the second seal surface is bad, the conduit function at the time of the suction from the ink lead-out port 127 and the capillary phenomenon deteriorates and thus the ink flows in the channel other than the first channel and the second channel of the movement member 300. If the ink is separated from the channel, the movement member 300 is displaced together with the sealing film 156 as the diaphragm and thus the first height reference surface 332A, the second height reference surface 334A and the third height reference surface 342 forming the first seal surface, and the first height reference surface 240, the second height reference surface 242 and the third height reference surface 244 forming the second seal surface are not in contact with each other. In the initial stage, the first height reference surface 332A, the second height reference surface 334A and the third height reference surface 342 forming the first seal surface, and the first height reference surface 240, the second height reference surface 242 and the third height reference surface 244 forming the second seal surface are not in contact with each other. Then, the ink is not charged in the sensor cavity 132A such that the ink residual quantity cannot be detected.
The improvement of the positional precision of the movement member 300 relative to the ink storing unit 200 is very important in the charging of the ink in the sensor cavity 132A in the initial stage in which the ink is introduced into the ink storing unit 200 and is realized in the present embodiment. Accordingly, in the states A to C of
The first height reference surface 332A, the second height reference surface 334A and the third height reference surface 342 forming the first seal surface, and the first height reference surface 240, the second height reference surface 242 and the third height reference surface 244 forming the second seal surface may also called an air bubble discharging seal surface. That is, if the first height reference surface 332A, the second height reference surface 334A and the third height reference surface 342 forming the first seal surface, and the first height reference surface 240, the second height reference surface 242 and the third height reference surface 244 forming the second seal surface are sealed with certainty, it is possible to facilitate the removal of the air bubbles remaining in the sensor cavity 132A by the suction from the ink lead-out port 127 and the capillary phenomenon.
At the time of the detection of the liquid and the initial stage, the seal load which is in contact with the first height reference surface 332A, the second height reference surface 334A and the third height reference surface 342 forming the first seal surface, and the first height reference surface 240, the second height reference surface 242 and the third height reference surface 244 forming the second seal surface can be ensured by only the urging force of the spring 153 as the urging member shown in
Next, the positioning of the sensor base 141 shown in
As described above, the ink storing unit 200 as the liquid storing unit has the opening 210 for exposing one surface of the sensor base 141. The opening 210 has three contact surfaces 212 which are in contact with one surface of the sensor base 141. If one surface of the sensor base 141 is in contact with the contact surfaces 212, the attachment heights of the sensor base 141 and the sensor chip 132 are positioned.
The opening 210 of the ink storing unit 200 as the liquid storing unit has an inner peripheral wall 210A having a shape corresponding to the outer appearance of the sensor base 141. A welding margin 214 welded with the sensor sealing film 142 is formed in the periphery of the opening 210.
The sensor base 141 inserted into the opening 210 is brought into contact with the contact surfaces 212 of the opening 210 of the ink storing unit 200 such that the height thereof is positioned and the two-dimensional planar position thereof is positioned by the inner peripheral wall 210A. Since the intersection of the orthogonal two axes X and Y is set in the center of the opening 210, the center of the sensor chip 132 mounted in the sensor base 141 is set to the intersection of the orthogonal two axes X and Y.
In
L1>L2 (1)
The meaning of Equation (1) will be described with reference to
The distances L1 and L2 will be described in more detail. When the design reference value of the distance L1 and L2 is L0 and a maximum value of a positive variation of the distance L1 is L01, L0<L1<L0+L01 is obtained and, when a maximum value of a negative variation of the distance L2 is −L02, L0−L02<L2<L0 is obtained. Here, L02<L01.
In this case, Equation (2) is satisfied.
L02<L1−L2<L01 (2)
If Equation (2) is satisfied, Equation (1) is necessarily satisfied. A difference between the distance L1 and the distance L2 is between an absolute value |L2| of the maximum value of the negative variation of the distance L2 and an absolute value |L1| of the maximum value of the positive variation of the distance L1.
In the initial stage in which the ink is introduced into the ink storing unit 200, the movement member 300 is displaced by the urging force of the spring 153 as the urging member, the sensor cavity seal surface 310A of the pressure-receiving plate 310 is brought into the sensor cavity seal surface 141C of the sensor base 141, and the sealing film 156 as the diaphragm is displaced at a position where the volume of the ink storing unit 200 is reduced. This state is shown in
In the pressurized state, unlike
As described above, although the present embodiment is described in detail, it will be apparent to those skilled in the art that the invention may be modified without departing from the new matter and effect of the invention. Accordingly, all modifications are included in the scope of the invention. For example, in the specification or drawing, the terms described together with other terms having the wider meaning or the same meaning may be replaced with the other terms in any one of the specification or the drawing.
The liquid detection is performed in order to perform the detection of the liquid pressure in addition to the detection of the liquid residual quantity.
That is, the liquid detecting unit is not limited to the piezoelectric detecting unit. If the displacement of the movement member 300 displaced by the liquid pressure can be detected, for example, an optical detecting unit may be used.
The use of the liquid storing container of the invention is not limited to the ink cartridge of the ink jet recording apparatus. The liquid storing container may be used in various liquid consumption apparatus having a liquid ejecting head for discharging a small quantity of liquid droplets.
The detailed examples of the liquid consumption apparatus include, for example, an apparatus including a coloring material ejecting head used for manufacturing color filters of a liquid crystal display, an apparatus including an electrode material (conductive paste) ejecting head used for forming electrodes of an organic EL display or a field emission display (FED), an apparatus including a bio organic material ejecting head used for manufacturing bio chips, and an apparatus including a sample ejecting head as a precise pipette, a printing apparatus and a micro-dispenser.
In the invention, the liquid is a material which can be ejected by a liquid consumption apparatus. A representative example of the liquid is the ink in the above-described embodiment. The liquid may be a material other than a material used for printing characters or images In the invention, the liquid may be a liquid or a liquid mixed with solid materials such as pigments or metal particles.
The entire disclosure of Japanese Patent Application Nos. 2007-274739, filed Oct. 23, 2007 and 2008-219263, filed Aug. 8, 2008 are expressly incorporated by reference herein.
Number | Date | Country | Kind |
---|---|---|---|
2007-274739 | Oct 2007 | JP | national |
2008-219263 | Aug 2008 | JP | national |