JP2004188933A - Ink container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink container capable of continuously detecting an amount of residual ink with high accuracy in a simple structure. <P>SOLUTION: This ink container comprises two conductive sections 5, 6 provided to opposing inner walls 3, 4 over an ink filling region, and two electrodes 8, 7 each being respectively provided to the uppermost end and the lowermost end of the conductive sections 5, 6, and a conductive float 2 floating in the ink filled in the container. The amount of the residual ink can be detected based on variation of a resistance value at a time when a voltage is applied across the electrodes 7, 8. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink container mounted on an inkjet printer or the like, and more particularly, to an ink container capable of detecting a remaining amount of ink.
[0002]
[Prior art]
In the case of an ink jet printer or the like, when the height of the ink liquid level in the ink container mounted on the carriage cannot be accurately detected, a serious trouble may occur. For example, if the near empty state cannot be detected and the printing operation is continued as it is, air may enter the nozzles of the print head and the print head may need to be replaced.
[0003]
Therefore, the remaining amount of ink in the ink container needs to be always accurately and reliably detected, and various proposals have conventionally been made. For example, the ink tank is filled with an ink absorber so that no malfunction occurs even by abrupt pressure fluctuation at the time of a head recovery operation or the like when air bubbles are mixed in, so that the ink remaining amount can be detected with high accuracy. There has been proposed a configuration in which a pair of electrode members is disposed inside (for example, see Patent Document 1).
[0004]
In addition, a magnet is attached to a float that floats in the ink stored in the ink tank, and the position of the magnet is detected by two Hall elements arranged at different heights outside the tank, thereby providing a full level. A configuration that can detect the state of near-empty and near-empty has also been proposed (for example, see Patent Document 2).
[0005]
[Patent Document 1]
JP-A-2-187365 (FIG. 1, page 3
4 lines to 3rd page, 3 lines)
[Patent Document 2]
JP-A-2001-141547 (FIG. 1, paragraphs “0014” and “00”)
18 ")
[0006]
[Problems to be solved by the invention]
By the way, it is needless to say that it is desirable for the user to be able to continuously detect not only the full level and the near empty state but also the remaining amount of the ink. However, with the configurations described in Patent Literature 1 and Patent Literature 2, the remaining amount of ink cannot be continuously detected. In addition, the configuration of the device is complicated, and data processing is not simple.
[0007]
The present invention has been made in view of such circumstances, and has as its object to provide an ink container having a simple configuration capable of continuously detecting the remaining amount of ink with high accuracy.
[0008]
[Means for Solving the Problems]
According to the present invention, means for solving the above-described problem are configured as follows.
[0009]
(1) It is characterized by comprising a conductive portion provided over the ink filling region of the inner wall of the container, and a float at least a part of which is conductive.
[0010]
In this configuration, if the remaining amount of ink changes, the height position of the float from the bottom of the container also changes, so in the circuit of the current flowing from the conductive portion provided along the inner wall of the container to the float via the ink. Changes the electric resistance value.
[0011]
Therefore, by detecting this change with a current value flowing through the circuit by an ammeter, the electrical resistance value is obtained, and the change in the value makes it possible to detect the remaining amount of ink steplessly and continuously with high accuracy. it can.
[0012]
The voltage applied to the above-described circuit is an alternating current in order to prevent a chemical change such as electrolysis of the ink. In the conductive portion, the inner wall of the container itself may be formed of a conductive material, or a conductive member may be attached to the inner wall of the container. In addition, the float may be formed of a conductive member itself, or a conductive member may be attached to a float that is not conductive, provided that at least a part is conductive and has a lower electric resistance value than the ink. Good.
[0013]
Since the structure is simple and does not require expensive materials, it can be provided at low cost. In addition, since the remaining amount of ink can be clearly grasped as a change amount of the electric resistance value according to the fluctuating height of the float, stable detection accuracy can be secured without requiring complicated data processing. it can.
[0014]
(2) Two conductive portions are provided, and each of the conductive portions is provided with an electrode.
[0015]
In this configuration, when a voltage is applied between the two electrodes, from one electrode, one conductive portion, the ink near one end of the float, the float, the ink near the other end of the float, and the other conductive portion, Current flows to the other electrode.
[0016]
For example, when two electrodes are provided at the lower ends of the two conductive portions (the lower part of the ink container), when the remaining amount of ink decreases and the height of the float lowers, the position of the electrode and the float position are changed. The distance between them becomes smaller. At this time, since the resistance value also changes, the remaining amount of ink can be obtained based on the change in the resistance value.
[0017]
Further, when two electrodes are provided on the upper and lower portions of the two conductive portions, respectively, if the electrical resistance values of the conductive portions are different, the remaining amount of ink decreases and the height position of the float decreases. Since the resistance value also changes, the remaining amount of ink can be determined based on the change in the resistance value.
[0018]
(3) The two conductive portions are provided on opposing surfaces of the inner wall of the container.
[0019]
In this configuration, with respect to the horizontal movement of the float, when the float approaches the conductive portion on one wall surface, the float moves away from the conductive portion on the opposite wall surface (by a close distance). Therefore, the resistance value of the ink between the conductive portions and the float also decreases in proportion to the moving distance on one side and increases on the other side, and both changes are offset. Therefore, the fluctuation of the resistance value between the two electrodes due to the floating of the float in the horizontal direction is reduced, and highly accurate detection is possible.
[0020]
(4) The two conductive portions have different resistance values, and the two electrodes are arranged at positions different in height from the container bottom surface.
[0021]
In this configuration, when a voltage is applied between the two electrodes, the one conductive portion, the ink near one end of the float, the ink near the one end of the float, the ink near the other end of the float, and the other conductive portion form the other conductive portion. The current flows to the electrode of the.
[0022]
For example, when the remaining amount of ink is reduced and the height position of the float is lowered, the distance between the position of the electrode provided on one wall surface and the float position is reduced, whereas the distance between the electrode position provided on the other wall surface is reduced. The distance between the provided electrode position and the float position is increased.
[0023]
At this time, since the resistance values of the conductive portions provided on both wall surfaces are different, the resistance value between both electrodes changes depending on the remaining amount of ink. Therefore, by grasping this change in the resistance value as a change in the current value detected by the ammeter, the remaining ink amount can be reliably detected.
[0024]
(5) Among the two conductive parts, the resistance of one conductive part is set to a value different from the resistance of the other conductive part by 10 times or more, and the unit length of each of the conductive parts It is characterized in that the electric resistance per contact is different in the height direction.
[0025]
In this configuration, since the electric resistance values of the two conductive portions are different from each other by 10 times or more, for example, the remaining ink amount is reduced and the float position is lowered. Is smaller, the distance between the electrode position and the float position is increased on the wall surface on the low resistance side by the same value as the width of this distance.
[0026]
At this time, the resistance between the electrodes decreases, and the flowing current increases. However, if the difference between the resistance values of both the wall surfaces is sufficiently large, the reduction width of the resistance value and, consequently, the expansion width of the current value also increase. Detection accuracy is improved.
[0027]
Further, since the electric resistance value per unit length of each conductive portion is made different in the height direction, the detection accuracy can be changed according to the remaining ink level. For example, assuming that the remaining ink amount is reduced and the float position is lowered, and the electrode position and the float position are reduced on the high resistance side wall, the electrode position and the float position on the low resistance side wall are equal to the reduced width. The distance between positions increases.
[0028]
In such a configuration, if the electrical resistance (resistivity) per unit length of the lower part of the wall on the high resistance side is set to be larger than the resistivity of the upper part of the wall, the lower part of the wall (zero residual amount) Since the decrease in the resistance value of the entire circuit between the electrodes due to the lowering of the liquid level (in the vicinity) is larger than that in the case of the upper part of the wall surface, the accuracy of detecting the remaining ink amount near zero ink remaining amount is improved.
[0029]
(6) The electric resistance of the two conductive portions and the float is smaller than the electric resistance of the ink.
[0030]
In this configuration, when the electric resistance of the conductive portion provided on the inner wall of the container is sufficiently smaller than the electric resistance of the ink, the current is directly passed from one electrode to the other electrode through the ink without passing through the wall surface or the conductive portion. Can be prevented from flowing, thereby improving the accuracy of detecting the remaining amount of ink.
[0031]
When the electric resistance of the float is sufficiently smaller than the electric resistance of the ink, it is possible to prevent a current from flowing from one electrode directly to the other electrode through the ink without passing through the float. The accuracy of quantity detection is improved.
[0032]
Further, if the resistance value of the float is set to a sufficiently small value, the influence of the error of the float resistance value on the entire system (resistance between electrodes) can be reduced.
[0033]
(7) The float is made of a material exhibiting water repellency to the contained ink, and has a specific gravity smaller than that of the ink.
[0034]
In this configuration, the specific gravity of the float is kept constant by preventing the ink from adhering and seeping into the float, and the float is stably floated on the ink, so that the change in the position of the ink liquid level between the electrodes is prevented. Since the change in the resistance value is clearly reflected, the detection accuracy of the remaining ink amount is improved.
[0035]
By adjusting the specific gravity of the float, the float floats on the ink in a stable state, and the change in the ink level is clearly reflected in the change in resistance between the electrodes, improving the accuracy of detecting the remaining amount of ink. I do.
[0036]
(8) The float is made of a foamable resin material.
[0037]
In this configuration, the float is made of a foaming resin, and its specific gravity is reduced, so that the float stably floats on the ink. And the accuracy of detecting the remaining amount of ink is improved.
[0038]
(9) When viewed from above the ink surface, the float has a cross-sectional shape smaller than the inner surface of the container, and can move up and down in accordance with the increase and decrease of the ink. It is characterized by being able to conduct through ink.
[0039]
It is an important requirement for the float to be able to move up and down smoothly in accordance with the increase and decrease of the ink in order to accurately detect the remaining ink amount. For this purpose, the cross-sectional shape of the float must be smaller than the inner surface of the ink container when viewed from above the ink liquid level. It is also important that a stable conductive state is maintained between the two conductive portions and the float. For that purpose, for example, the entire outer surface may be coated with a conductive material.
[0040]
(10) The two conductive portions are formed to have a width in the horizontal direction narrower than the inner wall of the container, while the float is made of a conductive material, and is orthogonal to a facing direction of the two conductive portions. It is characterized by being formed in a rectangular parallelepiped shape having a width in the direction as large as the inner wall of the container.
[0041]
In this configuration, a linear conductive portion extending in the vertical direction is formed at the center of the inner wall of the container, and the float made of the conductive material has a rectangular parallelepiped shape. Therefore, when the float rotates on the liquid surface without changing the position of the center of gravity, the corresponding distance between the float and the wall-shaped conductive portion formed linearly in the up-down direction does not change significantly. A change in the resistance value between the electrodes due to a change in the distance between the electrode and the end of the float can be avoided, and the accuracy of detecting the remaining amount of ink can be stably improved.
[0042]
(11) The two conductive portions are formed to have a width in the horizontal direction substantially equal to the inner wall of the container, while the float has a width in a direction orthogonal to a facing direction of the two conductive portions. Are formed in a rectangular parallelepiped shape having the same width as the conductive portion, and a narrow conductive portion is formed in a direction orthogonal to a facing direction of the two conductive portions in the float. It is characterized by.
[0043]
In this configuration, the float has a rectangular parallelepiped shape, and a linear conductor is horizontally attached to the center of the float. Even when the float is rotated on the liquid surface without changing the position of the center of gravity of the float, the distance between the conductive portion of the float and the conductive portion of the inner wall of the container does not change significantly. Therefore, the change in the resistance value between the electrodes caused by the change in the distance between the conductive portion of the inner wall of the container and the end of the float is reduced, and the accuracy of detecting the remaining amount of ink is stably improved.
[0044]
(12) A conductive elastic member is provided at both ends of the float for conducting the float to a conductive portion of the inner wall of the container.
[0045]
In this configuration, by electrically connecting the float and the conductive portion of the container inner wall with a conductive elastic member, the electrical effect of the ink between the float and the container inner wall on the entire circuit between the electrodes is reduced. And the accuracy of detecting the remaining amount of ink is improved.
[0046]
(13) The voltage applied between the electrodes is characterized in that a DC component is removed.
[0047]
In this configuration, by removing the DC component of the voltage applied between the electrodes, it is possible to prevent the occurrence of a chemical change such as electrolysis in the ink.
[0048]
(14) Electrodes are provided at two places near the bottom of the container, and conductive members that can come into contact with the two electrodes are provided on conductive floats floating in the ink filled in the container. The electric resistance is smaller than the electric resistance of the ink.
[0049]
In this configuration, in a state where the ink is empty, when a voltage is applied between the two electrodes, a conductive member provided on one of the floats and in contact with the one electrode, a conductive float, and a conductive float are provided. A current flows to the other electrode via a conductive member provided on the other side and in contact with the other electrode. In this case, the resistance between the two electrodes is low.
[0050]
On the other hand, when the remaining amount of ink is not empty, the float is raised from the bottom of the container, so that the contact state between the electrode provided near the bottom of the container and the conductive member provided on the float is released. In this state, between the electrode and the conductive member of the float, the current passes through the ink having a large resistance value. Therefore, the resistance value between the two electrodes rapidly increases.
[0051]
Therefore, when the ink becomes empty from a state in which the ink remains, the resistance value sharply decreases. Since it is detected that the ink is not empty based on this large change, the detection accuracy is clearly improved. In addition, since the configuration is simple and an expensive material is not required, it can be provided at a low cost.
[0052]
(15) The operation of detecting the remaining amount of ink is performed while the ink cartridge is mounted on the carriage and the ink is being ejected or the carriage is moving.
[0053]
If there is no float, the ink moves when the carriage moves. However, in this configuration, since the float is charged into the ink container, even if the carriage moves, the ink liquid level can be reduced by the float. Therefore, the float moves up and down smoothly in accordance with the remaining amount of ink, thereby enabling stable and accurate detection of the remaining amount of ink.
[0054]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an ink container according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0055]
[Configuration of printing device]
The configuration of a printing apparatus (inkjet printer) using the ink container of the present invention will be described with reference to FIGS. This printing apparatus performs printing by discharging ink onto a sheet (recording paper 201 (glossy paper)). As illustrated, a printing unit 81 that prints on the recording paper 201, a paper feeding unit 82 that supplies the recording paper 201 to the printer, a transport unit 83 that transports the recording paper 201 to the printing unit 81, And a discharge unit 85 that discharges the sheet 201.
[0056]
The paper supply unit 82 includes a paper supply tray 103, a separation plate 105, and a paper supply roller 104. The paper feed tray 103 accommodates and feeds recording paper 201 for printing. The separation plate 105 and the paper feed roller 104 separate the recording paper 201 stored in the paper feed tray 103 one by one and supply it to the transport unit 83.
[0057]
The transport unit 83 has a guide plate 106 and a transport roller 107. The guide plate 106 introduces the recording paper 201 fed from the feed roller 104 into the printing unit 81. The transport roller 107 transports the recording paper 201 that has passed over the guide plate 106 to the print head 101.
[0058]
The printing unit 81 has an ink carriage (carriage) 203, a shaft 202 for guiding the ink carriage 203, and a platen 102. The ink carriage 203 carries the print head 101 and moves along the shaft 202. And six ink cartridges (not shown) and a print head 101 are mounted.
[0059]
The ink cartridge stores and accumulates ink and supplies ink to the print head 101, and is mounted on the print head 101. Further, the printer 200 uses six different colors (black, yellow, magenta, cyan, light magenta, and light cyan) of ink, and includes six ink cartridges for storing the respective inks.
[0060]
The print head 101 forms an image on the recording paper 201 by discharging ink supplied from an ink cartridge from a discharge port (not shown). The shaft 202 is a guide member for guiding the ink carriage 203 so that it can move in the scanning direction. Here, the scanning direction is a direction perpendicular to the transport direction of the recording paper 201.
[0061]
The platen 102 serves as a table (printing table) on which the recording paper 201 is placed at the time of printing (ink ejection). This is for adjusting the distance. Further, the discharge unit 85 has a discharge roller 108 and a discharge tray 109, and the discharge roller 108 discharges the recording paper 201 printed by the print head 101 to the discharge tray 109.
[0062]
[Operation of printing device]
Next, the printing operation of the printer 200 will be described.
First, the user places the recording paper 201 on the paper feed tray 103 of the printer. When the printer 200 receives a print request from a computer or the like, the separation plate 105 and the paper feed roller 104 feed the recording paper 201 to the transport unit 83 one by one. Then, the fed recording paper 201 is transported by the transport roller 107 while being supported by the guide plate 106.
[0063]
Next, the print head 101 performs printing by ejecting ink onto the conveyed recording paper 201. This printing is performed by moving the ink carriage 203 having the print head 101 in the scanning direction along the shaft 202. That is, at the time of printing, the ink carriage 203 is arranged at a start position provided at one end (end of the shaft) in the scanning direction. Then, in response to a print request, it is moved in the scanning direction to a stop position provided at the other end.
[0064]
During this movement, the print head 101 ejects ink to the recording paper 201 in response to a print request. Thus, the print head 101 can print an image for one scan (scanned image). Note that the width of the scanned image corresponds to the vertical width of the ink head (the width in the sheet conveyance direction).
[0065]
After one scanned image is printed, the transport roller 107 transports the recording paper 201 on the platen 102 by a predetermined amount. During this conveyance, the ink carriage 21 returns to the start position (print scanning).
[0066]
In the printer 200, information corresponding to the print request is printed on the recording paper 201 by the print head 101 by repeatedly performing such print scanning. Finally, the printed paper is discharged to a paper discharge tray 109 via a paper discharge roller 108 and provided to a user as a document (printed matter).
[0067]
[Embodiment 1]
For example, as shown in FIG. 1, an ink tank 1 (ink container) according to the present embodiment includes a float 2 floating in ink 9 filled therein, a high-resistance section 5 serving as a conductive section, and a low-resistance section. 6 and electrodes 7 and 8. The high-resistance portion 5 and the low-resistance portion 6 are made of resistors having different electric resistance values from each other, and are adhered to the inner walls 3 and 4 of the container facing the ink tank 1.
[0068]
In the present embodiment, a 1 KΩ resistor is attached to the high resistance section 5 and a 100Ω resistor is attached to the low resistance section 6. The electrodes 7 and 8 are attached to the lower end of the container inner wall 3 on the high resistance side and the upper end of the container inner wall 4 on the low resistance side, respectively. The electrode 7 and the high resistance portion 5 and the electrode 8 and the low resistance portion 6 are electrically connected to each other.
[0069]
The float 2 floating on the ink filled between the facing container inner walls 3 and 4 is formed of a foaming resin, and the float 2 is located between the high-resistance section 5 and the low-resistance section 6. However, the distance (height) from the bottom surface of the ink tank 1 changes depending on the amount of ink.
[0070]
More preferably, the float 2 has water repellency. The shape of the float 2 is not limited, and may be, for example, a rectangular parallelepiped, a disk, or the like, which will be described later in detail.
[0071]
For the float 2, polypropylene (specific gravity 0.9) or polyethylene (specific gravity 0.91) can be used. However, the material of the float 2 is not limited to these. The specific gravity of the ink 9 is, for example, 1.05. On the other hand, if the float 2 having a specific gravity of 0.9 or less is used, the float 2 easily floats in the ink 9 filled in the ink tank 1.
[0072]
Further, in order to make the float 2 conductive, copper plating is performed on the entire outer surface of the float 2 or the entire surface except the upper portion. The material of the plating is not limited to copper. It is also possible to mix a conductive substance to form a resin.
[0073]
Here, a method of detecting the remaining amount of ink will be described. An alternating current is applied to both electrodes 7 and 8 in order to avoid a chemical change such as electrolysis. The current path includes one electrode (7 or 8), one resistor (5 or 6), float 2, and the other electrode (8 or 7) via the other resistor (6 or 5). So that it flows to
[0074]
In this configuration, it is more preferable that the resistance values of the resistance units 5 and 6 are sufficiently lower than the ink resistance value when the remaining ink amount is detected. Thus, the influence of the current flowing through the ink between the two resistance portions 5 and 6 without passing through the float 2 can be reduced.
[0075]
Here, when the remaining amount of the ink 9 is reduced and the position of the float 2 is lowered, the distance between the electrode 8 and the float 2 is increased by the reduction of the distance between the lower electrode 7 and the float 2. At this time, since the portion of the high resistance portion 5 in the circuit between the electrodes 7 and 8 decreases and the portion of the low resistance portion 6 increases, the resistance of the entire circuit decreases.
[0076]
Therefore, the resistance value of the entire system changes according to the remaining ink amount, and the remaining ink amount is obtained from this resistance value. That is, R is the entire system resistance value (detection value), RL is a low resistance value (eg, 100 Ω), RH is a high resistance value (eg, 1 KΩ), RF is a resistance value between two conductive parts through a float, and The ratio (the ratio between the remaining ink and the tank capacity) is represented by (R-RF-RL) ÷ (RH-RL).
[0077]
As a method of flowing the current and a method of detecting the resistance, a known method in which measurement is performed in a short time such as several milliseconds and the polarity is inverted for each measurement may be used.
[0078]
Further, by changing the electric resistivity (electric resistance value per unit length) on the wall surface side of the container by the height, the detection accuracy can be changed depending on the remaining ink level. For example, if the electrical resistivity of the lower wall portion of the high-resistance portion 5 is made larger than the electrical resistivity of the upper wall portion, the entire circuit between the electrodes due to the lowering of the liquid level at the lower wall portion (near the remaining amount) is reduced. Since the decrease width of the resistance value is larger than that in the case of the upper part of the wall surface, it is possible to improve the detection accuracy of the remaining ink amount near zero remaining amount.
[0079]
In other words, it is more preferable to continuously change the resistance of the low resistance portion 6 and / or the high resistance portion 5 in the height direction from the bottom surface of the ink tank 1. More specifically, the resistance values of the low-resistance portion 6 and the high-resistance portion 5 are changed so that the resistance value largely changes near the bottom surface of the ink tank 1, that is, near the position of the float 2 when the remaining amount of the ink becomes small. Should be set.
[0080]
In addition, the electric resistance of the float 2 is sufficiently smaller than the electric resistance of the ink 9 (about 1/10 or less) so that the current flows through the ink 2 between the float 2 and the resistance portion of the wall surface and flows into the float 2. Is more preferable. This prevents a current from flowing from the one electrode (7 or 8) directly to the other electrode (7 or 8) through the ink 9 without passing through the float 2 (in this case, erroneous detection). This can improve the accuracy of detecting the remaining amount of ink.
[0081]
Here, the shape of the float 2 will be described. First, as the shape of the float 2, a disk-like shape as shown in FIG. 2A or a rectangular parallelepiped shape as shown in FIG. Etc. When the float 2 has a disk shape, even when the float 2 is rotated on the liquid surface without changing the center position of the float 2, the distance between the outer peripheral portion of the float 2 and the resistance portions 5 and 6 inside the container wall ( Distance) does not change.
[0082]
As a result, it is possible to avoid a change in the resistance value between the electrodes 7 and 8 caused by a change in the distance between the resistance portions 5 and 6 and the end of the float 2, and a rectangular parallelepiped shape as shown in FIG. As compared with the case, the accuracy of detecting the remaining amount of ink can be improved.
[0083]
Further, as shown in FIG. 2C, the float 2 may be formed in a rectangular parallelepiped shape, and linear resistance portions 5 and 6 in the vertical direction may be provided substantially at the center inside the container wall surfaces 3 and 4. .
[0084]
Generally, as shown in FIG. 2B, when the float 2 has a rectangular parallelepiped shape and the entire float 2 is a conductor, as shown, when the float 2 rotates on the liquid surface, the top of the float 2 ( The resistance portions 5 and 6 on the wall surface come closer to each other, and the resistance value between the electrodes 7 and 8 changes even if the height of the ink 9 from the bottom surface of the ink tank 1 is the same. This causes a detection error.
[0085]
Furthermore, when the diagonal vertices of the float 2 contact the resistance portions 5 and 6, respectively, current flows from the resistance portions 5 and 6 on the diagonal line of the float 2, and the resistance value between the electrodes 7 and 8 changes. This also causes a detection error.
[0086]
However, as shown in FIG. 2C, the width (horizontal width) of the resistors (high-resistance portions 5 and low-resistance portions 6) provided on the inner walls 3 and 4 of the container in a cross section including the liquid level of the ink 9 ), Even if the float 2 rotates on the liquid surface without changing the position of the center of gravity, the high-resistance portion 5 and the low-resistance portion 6 of the container inner wall that is linear with the float 2 in the vertical direction are formed. Can be prevented from greatly changing.
[0087]
Accordingly, it is possible to avoid a change in the resistance value between the electrodes 7 and 8 caused by a change in the distance between the resistance portions 5 and 6 on the inner wall of the container and the end of the float 2, so that the detection accuracy of the remaining ink amount can be reduced. Can be improved.
[0088]
Further, as shown in FIG. 2D, the float 2 has a rectangular parallelepiped shape, a linear (band-shaped) conductor portion 11 is provided at the center of the float 2, and the resistance portions 5 and 6 on the inner wall side of the container are provided. , Can be substantially the same size as the inner walls 3 and 4 of the container. As an example of the configuration of the float 2 in this case, the conductor portion 11 may be attached to the float 2 made of a non-conductive resin material.
[0089]
In this regard, as shown in FIG. 2B, when the entire float 2 is a conductor, when the float 2 rotates on the liquid surface, the apex (corner) of the float 2 approaches the resistance portions 5 and 6 on the wall surface. Therefore, the resistance value of the ink changes. This causes a detection error.
[0090]
However, in the case of FIG. 2D, even when the float 2 rotates on the liquid surface without changing the position of the center of gravity, the distance relationship between the conductor portion 11 of the float 2 and the resistance portions 5 and 6 on the inner wall of the container. Does not change significantly, it is possible to avoid a change in the resistance value between the electrodes 7 and 8 caused by a change in the distance between the resistance portions 5 and 6 on the inner wall of the container and the float end, and to detect the remaining amount of ink. Accuracy can be improved.
[0091]
The mounting positions of the electrodes 7 and 8 are not particularly limited. For example, the electrode 7 may be mounted on the upper end of the container inner wall, and the electrode 8 may be mounted on the lower end of the container inner wall.
[0092]
Further, the materials constituting the low-resistance section 6 and the high-resistance section 5 may be different or may be the same. Specifically, the resistance values of the low-resistance portion 6 and the high-resistance portion 5 may be changed by using different materials, or by changing the thickness of the resistor using the same material. May be changed.
[0093]
In addition, the float 2 may be made of a single material, or may be made of a plurality of different materials. Specifically, for example, the float 2 may be a foamable resin and may be made of only a material having conductivity, and the surface of the foamable resin may be coated with a conductive material. . Alternatively, as a method of reducing the weight of the float 2, the float may have a hollow structure.
[0094]
[Embodiment 2]
In the present embodiment, for example, as shown in FIG. 3, a conductive thin plate-like elastic member is provided at both ends of the float 2 so that the float 2 and the low-resistance portion 6 and the high-resistance portion 5 are electrically connected to each other. 10 are provided.
[0095]
In such a configuration, when a voltage is applied between one electrode 7 provided at the lower end of the container inner wall 3 and the other electrode 8 provided at the upper end of the container inner wall 4, from one electrode 7, Through the high resistance portion 5 and the thin plate-shaped conductive elastic member 10 provided on the float 2, the flow reliably flows from the low resistance portion 6 to the other electrode 8.
[0096]
Thereby, the current flows directly from the one electrode (7 or 8) to the other electrode (7 or 8) through the ink 9 without passing through the one resistor (5 or 6) (in this case, Erroneous detection) can be prevented, and the accuracy of ink remaining amount detection is improved.
[0097]
In addition, a change in the ink passage distance due to a manufacturing error, a change in the resistance value of the ink itself, a difference in resistance depending on the type of the ink 9, a change in the ink resistance value at the time of detection due to an arrangement error at the time of detection (a tilt error of the float 2, etc.). The effect of the error can be reduced.
[0098]
[Embodiment 3]
In the present embodiment, as shown in FIG. 4, a conductive contact terminal (conductive member) A31 and a contact terminal (conductive member) B32 are provided on the lower surface of the float 22 made of a conductive material. The contact terminal B32 is configured so as to be able to be separated from and connected to the electrodes A27 and B28 provided at the lower portions on both sides of the ink container 21.
[0099]
In such a configuration, as shown in FIG. 4B, when the remaining amount of the ink is empty, the current flows from the electrode A27 provided near the bottom of the container to the conductive contact terminal A31 provided on the float 22. , The float 22, and the other conductive contact terminal B32 to the electrode B28 provided near the bottom surface of the container. In this case, the resistance value between the electrode A27 and the electrode B28 is low.
[0100]
When the remaining ink amount is not empty, as shown in FIG. 4A, the float 22 floats up, and a current flows from one electrode (A27 or B28) through the ink to the contact terminal (A31 or B32). The resistance value between the electrodes A27 and B28 increases. That is, the resistance value between the electrodes A27 and B28 changes more rapidly than when the contact terminals 31 and 32 are in contact with the electrodes A27 and B28. Since the ink empty is detected using the rapid change of the resistance value, the detection accuracy is improved.
[0101]
[Embodiment 4]
In the present embodiment, as shown in FIG. 5, conductive contact terminals A31 and B32 are provided on the lower surface of the float 22, and the float 22 and the electrodes A37 and B38 near the bottom of the container can be conducted. It is configured as follows. Further, similarly to FIG. 1, a high resistance surface 25, a low resistance surface 26, an electrode B38, and an electrode C39 are provided.
[0102]
In the above configuration, as described below, the remaining amount of ink can be continuously detected, and the ink empty can be detected with high accuracy. That is, as shown in FIG. 4B, when the remaining amount of ink is empty, the current flows from the electrode A27 provided near the bottom surface of the container to the conductive contact terminal A31 provided on the float 22 and the float 22. , The other conductive contact terminal B32, and the electrode B28 provided near the bottom surface of the container. In this case, the resistance between the electrodes is low.
[0103]
If the remaining amount of ink is not empty, the float rises and current flows from one electrode (27 or 28) through the ink having a large resistance value to the contact terminal (31 or 32). Get higher. That is, the resistance value between the electrodes changes more rapidly than when the contact terminals 31 and 32 are in contact with the electrodes 27 and 28. Since the ink empty is detected using the rapid change in the resistance value, the accuracy of the detection can be improved.
[0104]
Further, the remaining ink amount can be detected as follows. That is, an alternating current is applied to the electrodes 7 and 8 in order to avoid a chemical change such as electrolysis. The current path is such that the current flows to the other electrode (7 or 8) via the one electrode (7 or 8), the one resistor (5 or 6), the float 2, and the other resistor (5 or 6). Become. In this configuration, it is more preferable that the resistance values of the resistance units 5 and 6 are sufficiently lower than the ink resistance value when the remaining ink amount is detected. This makes it possible to reduce the influence of the current flowing through the ink between the two resistance portions 5 and 6 without passing through the float.
[0105]
Here, when the remaining amount of the ink 10 is reduced and the position of the float 2 is lowered, the interval between the electrode 8 and the position of the float 2 is increased by the reduction of the position of the electrode 7 and the position of the float 2. At this time, the portion of the high resistance portion 5 in the circuit between the electrodes decreases, and the portion of the low resistance portion 6 increases, so that the resistance of the entire circuit decreases. Therefore, the resistance value of the entire system changes according to the remaining ink amount, and the remaining ink amount can be continuously and continuously obtained from this resistance value.
[0106]
[Embodiment 5]
Further, the remaining amount of ink may be detected when the carriage on which the ink container is mounted operates. That is, when the carriage moves, the ink sways. However, in each of the above-described embodiments, the float is floated on the ink surface, so that the ink sway can be reduced, and the float can be used as the remaining amount of ink. , And smoothly moves up and down, and the measurement of the accuracy of the remaining ink amount can be performed with stability.
[0107]
[Embodiment 6]
As shown in FIG. 6, an ink tank 1 (ink container) according to the present embodiment includes a float 2, a conductive portion (hereinafter, referred to as a resistance portion), electrodes 7, 8, and a container inner wall 3 facing the ink tank 1. , 4 are provided with conductive portions 5, 6 made of a resistor having an electric resistance value of 100Ω, and the electrodes 7, 8 are disposed at the lower ends of the conductive portions 5, 6 in an electrically conductive state. Is established.
[0108]
The float 2 floating on the ink filled between the facing container wall surfaces 3 and 4 is formed of a foamable resin material. That is, the float 2 is disposed between the conductive portions 5 and 6, and the distance (height) from the bottom surface of the ink tank 1 changes according to the amount of the filled ink. I have.
[0109]
A method of detecting the remaining amount of ink by such a configuration will be described. First, an alternating current is applied to the electrodes 7 and 8 to avoid a chemical change such as electrolysis. As a current path, one electrode (7 or 8), one conductive part (5 or 6), float 2, and the other conductive part (6 or 5) are connected to the other electrode (8 or 7). It will flow.
[0110]
In this configuration, it is more preferable that the resistance values of the conductive portions 5 and 6 are set to values sufficiently lower than the ink resistance value when the remaining ink amount is detected. Thereby, the influence of the current passing through the ink between the two conductive portions 5 and 6 without passing through the float 2 can be reduced.
[0111]
Here, when the remaining amount of the ink 9 is reduced and the position of the float 2 is lowered, the distance between the electrode 8 and the position of the float 2 is also reduced by the reduction of the position of the electrode 7 and the position of the float 2. At this time, since the conductive portions 5 and 6 in the circuit between the electrodes are reduced, the resistance of the entire circuit is reduced. Therefore, the resistance value of the entire system changes according to the remaining ink amount, and the remaining ink amount can be obtained by detecting this resistance value.
[0112]
As a method of flowing the current and a method of detecting the resistance, a known method of performing measurement in a short time such as several milliseconds and inverting the polarity every measurement may be used. Also, by changing the electrical resistivity (electrical resistance value per unit length) on the wall surface side of the container by the height, the detection accuracy is changed according to the remaining ink level. For example, the detection accuracy becomes closer to the empty state. Can also be improved.
[0113]
[Embodiment 7]
As shown in FIG. 7, an ink tank 1 (ink container) according to the present embodiment includes a float 2, a conductive portion (hereinafter, referred to as a resistance portion) 5, electrodes 7, 8, and an inner wall 3 of the container. Is provided with a resistor having an electric resistance of 100Ω. One electrode 7 is attached to the lower end of the container inner wall 3, and the other electrode 8 is attached to the upper part of the container inner wall 4. The one electrode 7 and the conductive portion 5 are electrically connected. Further, the electrode 8 and the float 2 are electrically connected by a conductive wire 11.
[0114]
The float 2 floating on the ink 9 filled in the container is formed of a foamable resin material. The distance (height) of the float 2 from the bottom surface of the ink tank 1 changes depending on the amount of the filled ink. The material and shape of the float 2 are the same as those of the first embodiment.
[0115]
The method of detecting the remaining amount of ink in this case will be described. First, an alternating current is applied to the electrodes 7 and 8 to avoid a chemical change such as electrolysis. As a current path, the current flows to the electrode 8 via the electrode 7, the conductive portion 5, the float 2, and the conductive wire 11. Note that, in this configuration, it is more preferable that the resistance value of the conductive portion 5 be sufficiently lower than the ink resistance value when the remaining ink amount is detected.
[0116]
Here, when the remaining amount of the ink 10 is reduced and the position of the float 2 is lowered, the portion of the conductive portion 5 in the circuit between the electrodes is reduced by the reduced size of the position of the electrode 7 and the position of the float 2, so that the entire circuit is reduced. Resistance decreases. Therefore, the resistance value of the entire system changes according to the remaining ink amount, and the remaining ink amount is obtained from the resistance value. By changing the electrical resistivity (the electrical resistance per unit length) of the conductive portion 5 disposed on the inner wall 3 of the container according to the height, the detection accuracy can be changed according to the remaining ink level.
[0117]
Embodiment 8
When two conductive portions are provided on the inner wall of the container, the position does not have to be the facing surface of the container, and the conductive portion may be provided on each of adjacent wall surfaces of the container. Further, two conductive portions may be provided on the same wall surface of the container.
[0118]
The present invention is not limited to an ink jet printer having an ink container mounted thereon, as shown in FIGS. 8 and 9, but may be any printer provided with a carriage capable of scanning with an ink container mounted thereon. It is applicable to the present invention regardless of other forms and configurations.
[0119]
【The invention's effect】
As is clear from the above description, the present invention has the following effects.
[0120]
(1) Since there is provided a conductive portion disposed over the ink-filled region of the inner wall of the container and a float that is at least partially conductive, a circuit that flows from the conductive portion to the float via the ink is provided. By detecting the current, an electric resistance value that changes according to the height of the float can be obtained, whereby the remaining amount of the ink can be continuously and accurately detected steplessly.
[0121]
Since the structure is simple and does not require expensive materials, it can be provided at low cost. In addition, since the remaining amount of ink can be clearly grasped as a change amount of the electric resistance value according to the fluctuating height of the float, stable detection accuracy can be secured without requiring complicated data processing. it can.
[0122]
(2) Since two conductive portions are provided and each of the conductive portions is provided with an electrode, for example, when two electrodes are provided at the lower ends (lower portions of the ink containers) of the two conductive portions, respectively, As the remaining amount decreases and the height position of the float decreases, the distance between the electrode position and the float position decreases. At this time, since the resistance value also changes, the remaining amount of ink can be obtained based on the change in the resistance value.
[0123]
Further, when two electrodes are provided on the upper and lower portions of the two conductive portions, respectively, if the electrical resistance values of the conductive portions are different, the remaining amount of ink decreases and the height position of the float decreases. Since the resistance value also changes, the remaining amount of ink can be determined based on the change in the resistance value.
[0124]
(3) Since the two conductive portions are disposed on the opposing surfaces of the inner wall of the container, when the float approaches the conductive portion on one wall, the float is separated from the conductive portion on the opposing wall. Moving away, the resistance of the ink between both conductive parts and the float becomes lower on the one hand and higher on the other hand, and both changes cancel each other out, so that the change in the resistance between the two electrodes becomes smaller and the float has a lower resistance. Fluctuations in the resistance value due to floating are reduced, and highly accurate detection is possible.
[0125]
(4) Since the two conductive portions having different resistance values are disposed at positions different from each other in height from the bottom of the container, the resistance value between the two electrodes changes depending on the remaining amount of ink. By detecting the change state of the resistance value as the change of the current value, the remaining amount of the ink can be reliably detected.
[0126]
(5) Since the electric resistance values of the two conductive portions are different from each other by a factor of 10 or more, for example, the remaining ink amount decreases and the float position decreases, and the distance between the electrode position and the float position on the wall surface on the high resistance side. Is smaller, the distance between the electrode position and the float position is increased on the wall surface on the low resistance side by the same value as the distance width.
[0127]
At this time, the resistance between the electrodes decreases, and the flowing current increases. However, if the difference between the resistance values of both the wall surfaces is sufficiently large, the reduction width of the resistance value and, consequently, the expansion width of the current value also increase. Detection accuracy is improved.
[0128]
Further, since the electric resistance value per unit length of each conductive portion is made different in the height direction, the detection accuracy can be changed according to the remaining ink level. For example, assuming that the remaining ink amount is reduced and the float position is lowered, and the electrode position and the float position are reduced on the high resistance side wall, the electrode position and the float position on the low resistance side wall are equal to the reduced width. The distance between positions increases.
[0129]
Furthermore, if the electrical resistance (resistivity) per unit length of the lower wall part on the high resistance side is set to be larger than the resistivity of the upper wall part, the liquid level lower at the lower wall part (near the remaining amount) Since the decrease width of the resistance value of the entire circuit between the electrodes is larger than that in the case of the upper part of the wall surface, the accuracy of detecting the remaining amount of ink near zero ink remaining amount is improved.
[0130]
(6) Since the electric resistance of the two conductive portions and the float is smaller than the electric resistance of the ink, the current flows from one electrode directly to the other electrode through the ink without passing through the wall surface or the conductive portion. Since the flow can be prevented, the accuracy of the remaining ink amount detection is improved.
[0131]
When the electric resistance of the float is sufficiently smaller than the electric resistance of the ink, it is possible to prevent a current from flowing from one electrode directly to the other electrode through the ink without passing through the float. The accuracy of quantity detection is improved.
[0132]
Furthermore, if the resistance value of the float is set to a sufficiently small value, the influence of the error in the resistance value of the float on the entire system (resistance between electrodes) can be reduced, and the detection accuracy is improved.
[0133]
(7) The float is made of a material exhibiting water repellency with respect to the contained ink, and its specific gravity is smaller than the specific gravity of the ink. Since the specific gravity is kept constant and the float stably floats on the ink, a change in the position of the ink surface is clearly reflected in a change in the resistance value between the electrodes, and the accuracy of detecting the remaining amount of the ink is improved.
[0134]
In addition, by adjusting the specific gravity of the float and floating the float on the ink in a stable state, the change in the ink liquid level can be clearly reflected in the change in the resistance value between the electrodes. The detection accuracy is improved.
[0135]
(8) Since the float is made of a foaming resin and its specific gravity is light, the float floats stably on the ink, so that the position change of the ink liquid level is clearly defined by the change of the resistance value between the electrodes. And the accuracy of detecting the remaining amount of ink is improved.
[0136]
(9) When viewed from above the ink liquid level, the float has a cross-sectional shape smaller than the inner surface of the container, can move up and down following the increase and decrease of the ink, and can directly or Conduction is possible via the ink, so that the float moves up and down smoothly following the increase and decrease of the ink, and a stable conduction state is maintained, so that it is possible to stably improve the detection accuracy of the remaining ink amount. it can.
[0137]
(10) A band-shaped conductive portion extending in the vertical direction is formed in the center of the inner wall of the container, and the float made of the conductive material has a rectangular parallelepiped shape. Therefore, the float rotates on the liquid surface without changing the position of the center of gravity. At this time, since the corresponding distance between the float and the wall-shaped conductive portion formed linearly in the vertical direction does not change significantly, the distance between the electrodes caused by the change in the distance between the conductive portion of the container inner wall and the end of the float does not change. A change in the resistance value can be avoided, and the accuracy of detecting the remaining amount of ink is stably improved.
[0138]
(11) Since the float has a rectangular parallelepiped shape and the strip-shaped conductor is horizontally attached to the center of the float, even if the float is rotated on the liquid surface without changing the center of gravity of the float, The distance between the conductive portion of the container and the conductive portion on the inner wall of the container does not change significantly. Therefore, the change in the resistance value between the electrodes caused by the change in the distance between the conductive portion of the inner wall of the container and the end of the float is reduced, and the accuracy of detecting the remaining amount of ink is stably improved.
[0139]
(12) By electrically connecting the float and the conductive portion on the inner wall of the container with a conductive elastic member, it is possible to reduce the electrical influence of the ink between the float and the inner wall on the entire circuit between the electrodes. This improves the accuracy of detecting the remaining amount of ink.
[0140]
(13) By eliminating the DC component of the voltage applied between the electrodes, it is possible to prevent the occurrence of a chemical change such as electrolysis in the ink.
[0141]
(14) At two locations near the bottom of the container, electrodes are provided, and a conductive member is provided on the conductive float so as to be able to contact the electrodes, and the electric resistance of the float is smaller than the electric resistance of the ink. Therefore, when the ink becomes empty from the state in which the ink remains, the resistance value sharply decreases. Since it is detected that the ink is not empty based on this large change, the detection accuracy is clearly improved. In addition, since the configuration is simple and an expensive material is not required, it can be provided at a low cost.
[0142]
(15) A float is put into the container, and the operation of detecting the remaining amount of ink is performed during ink discharge or movement of the carriage. Therefore, even if the carriage moves, the fluctuation of the ink liquid level is reduced by the float. The float can be moved up and down smoothly in accordance with the remaining amount of ink, thereby enabling stable and accurate detection of the remaining amount of ink.
[Brief description of the drawings]
FIG. 1 is a configuration explanatory view of an ink container according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of shapes of the various floats.
FIG. 3 is a diagram illustrating the configuration of another ink container.
FIG. 4 is a diagram illustrating the configuration of still another ink container.
FIG. 5 is an explanatory diagram of the configuration of the different ink container.
FIG. 6 is an explanatory diagram of a configuration of an ink container that is different from that of FIG.
FIG. 7 is a diagram illustrating the configuration of another ink container.
FIG. 8 is a perspective view of the inkjet printer.
FIG. 9 is a sectional view of the ink jet printer.
[Explanation of symbols]
2,22-float
3,4-container inner wall
5,6-conductive part
7, 8, A27, B28, A37, B38-electrode
9,29-ink
10-conductive elastic member
11-conductor part
A31, B32-conductive member
203-carriage

Claims (15)

An ink container comprising: a conductive portion disposed over an ink filling region of an inner wall of a container; and a float at least partially conductive. The ink container according to claim 1, wherein two of the conductive portions are provided, and each of the conductive portions is provided with an electrode. 3. The ink container according to claim 2, wherein the two conductive portions are disposed on opposing surfaces of the container inner wall. The ink according to claim 2, wherein the two conductive portions have different resistance values, and the two electrodes are arranged at positions different from each other in height from a container bottom. container. Among the two conductive portions, the resistance value of one conductive portion is set to a value different from the resistance value of the other conductive portion by 10 times or more, and per unit length of each of the conductive portions. The ink container according to claim 4, wherein the electric resistance values are different in the height direction. 3. The ink container according to claim 2, wherein the electrical resistance of the two conductive portions and the float is smaller than the electrical resistance of the ink. 2. The ink container according to claim 1, wherein the float is made of a material exhibiting water repellency to the contained ink, and has a specific gravity smaller than that of the ink. The ink container according to claim 1, wherein the float is made of a foamable resin material. When viewed from above the ink liquid level, the float has a cross-sectional shape smaller than the inner surface of the container, and can move up and down in accordance with the increase and decrease of the ink. 3. The ink container according to claim 2, wherein the ink container is electrically connected. The two conductive portions are formed in a strip shape having a narrow width in the horizontal direction, while the float is formed of a conductive material, and the width of the two conductive portions in a direction orthogonal to a facing direction is the container. The ink container according to claim 3, wherein the ink container is formed in a rectangular parallelepiped shape as wide as the inner wall. The two conductive portions have a width in a horizontal direction substantially equal to the inner wall of the container, and the float has a width in a direction orthogonal to a facing direction of the two conductive portions. It is formed in a rectangular parallelepiped shape having the same width as the conductive portion, and a narrow band-shaped conductive portion is formed in a direction orthogonal to a facing direction of the two conductive portions in the float. The ink container according to claim 3, wherein: 4. The ink container according to claim 3, wherein a conductive elastic member is provided at both ends of the float for electrically connecting the float to a conductive portion of the inner wall of the container. The ink container according to claim 2, wherein a DC component is removed from the voltage applied between the electrodes. Electrodes are provided at two places near the bottom surface of the container of the conductive part, and the float is provided with a conductive member capable of contacting with each of the two electrodes. The ink container according to claim 1, wherein the ink container is made smaller. The ink container according to any one of claims 1 to 14, wherein the operation of detecting the remaining amount of ink is performed while the ink is mounted on the carriage and the ink is being moved or the carriage is moving.

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