Ink tank

Abstract

To provide an ink tank reducing variations in a liquid surface position detected even in an inclined state.SOLUTION: An ink tank 18 is equipped with an ink storage portion 121 that stores ink, a detecting portion 60 that detects a position of a liquid surface L of the ink in the ink storage portion 121, a supplying portion 115 that supplies the ink to the outside, and a filter portion 113 that is disposed in the ink storage portion 121 and is interposed between the ink storage portion 121 and the supplying portion 115. In a see-through view from a side surface 129, the filter portion 113 is disposed in a -Z direction with respect to the detecting portion 60. The detecting portion 60 is disposed at a center portion of the ink storage portion 121 in a direction along a Y-axis orthogonal to the -Z direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an ink tank. [Background technology]

[0002] Conventionally, inkjet printers have been known that print by ejecting ink from an inkjet head. The ink is stored in a container such as an ink tank that is installed in the inkjet printer. For example, Patent Document 1 discloses an ink tank that can be refilled by the user and that detects the liquid level of the stored ink. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-175294 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the ink tank described in Patent Document 1 had an issue in that the detected liquid level was prone to variation when the inkjet printer was installed in a tilted position. Specifically, a pair of conductive members is provided as a liquid level sensor. The ends of the pair of conductive members are positioned at different vertical positions. When the inkjet printer is tilted, the liquid level in the ink tank also tilts. As a result, the positional relationship between the liquid level position and the ends of the pair of conductive members changes, which could result in a detection result that differs from the actual liquid level position. In other words, there was a need for an ink tank that reduces variation in the detected liquid level position even when the inkjet printer is installed in a tilted position. [Means for solving the problem]

[0005] The ink tank comprises an ink storage section that stores ink, a detection section that detects the position of the ink liquid surface within the ink storage section, a supply section that supplies the ink to the outside, and a filter section that is disposed in the ink storage section and interposed between the ink storage section and the supply section, and when viewed through from the side, the filter section is disposed in a first direction relative to the detection section, and the detection section is disposed in the center of the ink storage section in a second direction perpendicular to the first direction. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a perspective view showing the configuration of an inkjet printer equipped with an ink tank according to a first embodiment. [Figure 2] FIG. 2 is a schematic perspective view showing the configuration of an ink tank. [Figure 3] FIG. 2 is a schematic perspective view showing the configuration of an ink tank. [Figure 4] FIG. 3 is a schematic cross-sectional view showing the configuration of a detection unit. [Figure 5] FIG. 10 is a schematic perspective view showing the configuration of an ink tank according to a second embodiment. [Figure 6] FIG. 2 is a schematic perspective view of an ink tank according to the embodiment. [Figure 7] FIG. 2 is a schematic perspective view of an ink tank according to the embodiment. [Figure 8] FIG. 10 is a schematic perspective view of an ink tank of a comparative example. [Figure 9] FIG. 10 is a schematic perspective view of an ink tank of a comparative example. [Figure 10] FIG. 10 is a schematic perspective view of an ink tank of a comparative example. [Figure 11] FIG. 10 is a schematic perspective view of an ink tank of a comparative example. [Figure 12] FIG. 10 is a schematic perspective view of an ink tank of a comparative example. [Figure 13A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 13B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 14A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 14B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 15A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 15B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 16A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 16B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 17A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 17B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 18A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 18B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 19A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 19B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 20A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 20B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 21A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 21B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 22A] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 22B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 23A]FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. [Figure 23B] FIG. 4 is a schematic perspective view showing the ink level and the like in an inclined ink tank. DETAILED DESCRIPTION OF THE INVENTION

[0007] In the following embodiments, an ink tank mounted in an inkjet printer will be exemplified and explained with reference to the drawings. Note that the inkjet printer in which the ink tank of the present invention is mounted is not limited to the off-carriage type. Note that an inkjet printer may also be simply referred to as a printer.

[0008] In the following figures, X, Y, and Z axes are used as mutually orthogonal coordinate axes as necessary, with the direction indicated by each arrow being the + direction and the direction opposite the + direction being the - direction. When a printer incorporating the ink tank of the present invention is installed on a horizontal surface, the first direction coincides with the vertical direction, and the second direction perpendicular to the first direction coincides with the horizontal direction. In the above case, specifically, the -Z direction is the first direction, and the direction along the Y axis is the second direction. Note that the sizes of the various components have been made different from their actual sizes for ease of illustration.

[0009] 1. First embodiment The printer 1 equipped with the ink tank 18 according to this embodiment is a printing device that prints by depositing ink droplets onto a printing medium such as paper.

[0010] As shown in FIG. 1, the printer 1 has a substantially rectangular parallelepiped exterior housing 20. An operation panel 17 and a tank unit 19 are arranged on the surface of the exterior housing 20 facing the -Y direction. The operation panel 17 has an operation unit 15 and a display unit 16. The operation unit 15 has buttons for performing various operations on the printer 1. The display unit 16 displays various information about the printer 1. The display unit 16 is, for example, a liquid crystal panel. The operation panel 17 and the display unit 16 may be integrated into a touch panel. The printer 1 also has a control unit (not shown). The control unit controls the overall operation of the printer 1.

[0011] The tank unit 19 houses five ink tanks 18a, 18b, 18c, 18d, and 18e inside. The ink tanks 18a, 18b, 18c, 18d, and 18e are sometimes collectively referred to as ink tanks 18. Although not shown in the figures, the ink tanks 18 contain ink used for printing by the printer 1.

[0012] When the ink capacity of the ink tank 18 of the printer 1 becomes low, the user can pour ink from an ink storage container into the ink tank 18 to replenish it. Note that the ink tank 18 does not necessarily have to be refillable with ink, and the ink tank 18 may be replaceable. Also, the number of ink tanks 18 is not limited to five.

[0013] When refilling the ink tank 18 with ink from an ink storage container, the image reading unit 13 above the exterior housing 20 and the cover 29 above the tank unit 19 are each flipped up in the +Z direction. This opens the fill port (not shown) of the ink tank 18 in the +Z direction, allowing ink to be refilled.

[0014] The ink tank 18 may contain five types of ink each having a different color, or may contain inks having the same color. The five types of ink may also include a clear ink, or a treatment liquid such as a coating liquid.

[0015] Five windows 21 are provided on the front surface 99 of the tank unit 19 at positions corresponding to the ink tanks 18. Each window 21 is a through-hole provided in the exterior housing 20. Through each window 21, the ink viewing portion 61 of the corresponding ink tank 18 can be seen.

[0016] The ink visualizing section 61 is part of the wall of the housing of the ink tank 18. The ink containing section (described later) inside the ink tank 18 can be seen through the ink visualizing section 61. This allows the user to grasp the approximate amount of ink contained in the ink tank 18.

[0017] The exterior housing 20 houses a printing unit 23 that prints by depositing ink on a print medium. The printing unit 23 includes ink pipes 24, an inkjet head 25, and a carriage 26. The ink pipes 24 include multiple pipes that individually supply each ink contained in the ink tanks 18 to the inkjet head 25. For ease of illustration, the ink pipe 24 is shown as a single pipe in FIG. 1.

[0018] The inkjet head 25 is disposed in the -Z direction of the carriage 26. Ink is supplied to the inkjet head 25 from the ink tank 18 via the ink pipes 24. Although not shown, the inkjet head 25 has an actuator serving as a driving means therein and a plurality of nozzle rows in the -Z direction. In the inkjet head 25, the actuator is driven to eject the corresponding ink as ink droplets from the plurality of nozzles in each nozzle row.

[0019] The actuator of the inkjet head 25 may be a piezoelectric element, an electromechanical conversion element that displaces a vibration plate by electrostatic adsorption, or an electrothermal conversion element that ejects ink droplets by bubbles generated by heating.

[0020] The carriage 26 can be moved back and forth along the X axis by a drive unit (not shown). Although not shown, the printer 1 also has a transport unit that transports the print medium in the -Y direction relative to the carriage 26. Therefore, the inkjet head 25 can scan along the X axis and move along the Y axis relative to the print medium. By transporting the print medium while scanning the inkjet head 25 and controlling the ink color, the number and mass of ink droplets, and the timing of ejection, a color image or the like can be printed on the print medium.

[0021] 2, the ink tank 18 includes an inlet 111, an ink storage section 121, a detection section 60, a visual confirmation section 61, a filter section 113, and a supply section 115. Here, in FIG. 2, the ink flow path from the filter section 113 to the supply section 115 is not shown.

[0022] The housing of the ink tank 18 is roughly cubic. The ink tank 18 has a pair of side surfaces 129 that face each other in the direction along the X axis, a pair of side surfaces 128 that face each other in the direction along the Y axis, and a top surface 127 and a bottom surface 126 that face each other in the direction along the Z axis. The length of the side surfaces 129 along the Y axis is longer than the length of the side surfaces 128 along the X axis. When the printer 1 is placed on a horizontal surface, the -Z direction coincides with the vertical direction, and in the ink tank 18 installed in the printer 1, the top surface 127 and the bottom surface 126 face along the horizontal plane.

[0023] The ink tank 18 is made of a resin such as polyolefin, polycarbonate, or polyester. It is preferable that the material of the ink tank 18 is resistant to deterioration or dissolution by the ink contained therein. The ink tank 18 may also be partially made of a resin film, glass, metal, or other material. When the detection unit 60 employs a microtrap antenna system (described later), the ink tank 18 is primarily made of a dielectric material such as resin.

[0024] The ink containing section 121 is provided inside the housing of the ink tank 18. The ink containing section 121 contains ink. In this embodiment, the ink containing section 121 is a substantially cubic space, but the shape of the ink containing section 121 is not limited to this. The ink containing section 121 may have a partition, a compartment, a flow path, a valve, etc.

[0025] The filter section 113 is disposed on a surface that conforms to the bottom surface 126 of the ink containing section 121. The filter section 113 includes, for example, a metal mesh. The filter section 113 is interposed between the ink containing section 121 and the supply section 115, and captures foreign matter and the like contained in the ink contained in the ink containing section 121.

[0026] The supply unit 115 is disposed in the +Y direction of the bottom surface 126 and protrudes in the -Z direction. The supply unit 115 supplies ink contained in the ink containing unit 121 to the outside of the ink tank 18. The ink is supplied from the ink containing unit 121 through the filter unit 113 and the supply unit 115 to the ink pipe 24 described above.

[0027] When the printer 1 is placed on a horizontal surface, the detection unit 60 is placed on the side 129 that is longer in the horizontal direction, i.e., along the Y axis, out of the sides 128 and 129 that intersect with the horizontal surface. This makes it easy to secure space for placing the detection unit 60.

[0028] When the printer 1 is placed on a horizontal surface, the detection unit 60 is located at the center of the ink containing unit 121 in the direction along the Y axis, which is the second direction, when viewed through the side surface 129. Also, when viewed through the same, the filter unit 113 is located in the -Z direction, which is the first direction, relative to the detection unit 60.

[0029] The central part of the ink containing section 121 refers to the central region along the Y axis of the ink containing section 121 when viewed from the side in the -X direction. Therefore, "disposed in the central part of the ink containing section 121" means that the center line of the detection section 60 along the Z axis in the direction along the Y axis is closer to the center line of the ink containing section 121 along the Z axis in the direction along the Y axis than the side surface 128 of the ink containing section 121.

[0030] When the printer 1 is installed at an angle, the ink tank 18 assumes one of the following positions: tilted in the direction of rotation around a line along the X-axis; tilted in the direction of rotation around a line along the Y-axis; or tilted in the direction of rotation around a line in the XY plane that intersects the X-axis and Y-axis. Of these tilts, tilt in the direction of rotation around a line along the X-axis causes greater deviation in the ink liquid level when viewed through the rotation axis. In other words, conventionally, tilt in the direction of rotation around a line along the X-axis results in greater variation in the detected ink liquid level. Therefore, this specification will discuss tilt in the direction of rotation around a line along the X-axis.

[0031] The detection unit 60 detects the position of the ink surface in the ink containing unit 121. The detection unit 60 includes receiving electrodes 131 and 133 and a transmitting electrode, which will be described later. The receiving electrodes 131 and 133 are arranged on a side surface 129 of the ink tank 18 facing the -X direction. The transmitting electrode is arranged on a side surface 129 facing the +X direction.

[0032] The receiving electrodes 131 and 133 are provided on the housing of the ink tank 18. When viewed from the side in the -X direction, the receiving electrodes 131 and 133 are each a substantially rectangular shape with the longitudinal direction along the Y axis. When viewed from the side in the -X direction, the receiving electrode 131 is disposed closer to the top surface 127, and the receiving electrode 133 is disposed closer to the bottom surface 126.

[0033] The receiving electrode 131 detects whether there is a sufficient amount of ink contained in the ink containing section 121. The receiving electrode 133 detects whether there is an insufficient amount of ink contained. Note that other receiving electrodes may be disposed between the receiving electrodes 131 and 133 in the direction along the Z axis.

[0034] An inlet 111 is provided on the top surface 127 of the ink containing section 121. More specifically, when the printer 1 equipped with the ink tank 18 is placed on a horizontal surface, the inlet 111 is positioned closer to one end than the center in the direction along the Y axis. Specifically, the inlet 111 is positioned closer to the side surface 128 in the -Y direction and in the +Z direction relative to the ink containing section 121 when viewed from the side in the -X direction.

[0035] The inlet 111 is, for example, a tubular member whose tip in the +Z direction protrudes from the top surface 127 and whose tip in the -Z direction communicates with the inside of the ink containing section 121. Ink is replenished into the ink containing section 121 through the inlet 111. Because the inlet 111 is disposed on the top surface 127, ink can be poured from the inlet 111 into the ink containing section 121 by gravity. The inlet 111 may have a cap or the like at its tip in the +Z direction.

[0036] The ink tank 18 is provided with a visible portion 61. When the printer 1 equipped with the ink tank 18 is placed on a horizontal surface, the visible portion 61 is positioned closer to one end than the center in the direction along the Y axis, which is the horizontal direction. Specifically, the visible portion 61 is positioned on the side surface 128 in the -Y direction.

[0037] The visible portion 61 is made of a light-transmitting material such as resin or glass. The liquid level of the ink in the ink containing portion 121 can be seen through the visible portion 61. The visible portion 61 only needs to allow the liquid level to be seen, and may be made of, for example, a translucent resin.

[0038] 3, the transmitting electrode 122 has a substantially rectangular shape when viewed from the side in the +X direction. The transmitting electrode 122 is provided on the housing of the ink tank 18, facing the receiving electrodes 131 and 133 in the direction along the X axis. A pulse wave is transmitted from the transmitting electrode 122. The pulse wave is received by the receiving electrodes 131 and 133 via the housing of the ink tank 18 and the ink containing section 121. Details of the detection unit 60, which includes the receiving electrodes 131 and 133 and the transmitting electrode 122, will be described later.

[0039] 4, the detection unit 60 includes a transmitting electrode 122, receiving electrodes 131 and 133, and a processing unit (not shown). The detection unit 60 detects the position of the ink surface in the ink storage unit 121, i.e., the amount of ink stored. When the ink tank 18 is installed in the printer 1, the processing unit is electrically connected to the control unit of the printer 1 via wiring (not shown).

[0040] Methods for detecting the ink volume include known liquid level sensors such as an optical type, a float type, a microtrap antenna type, and an ultrasonic type. In this embodiment, a detection method using a microtrap antenna type is used as the liquid level sensor, but the invention is not limited to this.

[0041] The transmitting electrode 122 and the receiving electrodes 131, 133 are arranged facing each other in the direction along the X-axis, sandwiching the ink tank 18. The transmitting electrode 122 and the receiving electrodes 131, 133 include a conductive material such as a metal or alloy, such as gold, silver, copper, aluminum, or iron.

[0042] The receiving electrodes 131 and 133 are provided at positions overlapping with the transmitting electrode 122 when viewed through from the -X direction. The receiving electrodes 133 and 131 are arranged in this order from the bottom surface 126 side toward the +Z direction. The receiving electrode 131 is arranged at a height position H1, and the receiving electrode 133 is arranged at a height position H3.

[0043] The transmitting electrode 122 and the receiving electrode 131 are parallel plates facing each other, forming a capacitor 171. Similar to the capacitor 171, the transmitting electrode 122 and the receiving electrode 133 form a capacitor 173.

[0044] The capacitance of the capacitors 171 and 173 is determined by the relative dielectric constant of the material interposed between the electrodes of the capacitors 171 and 173. The relative dielectric constant of air is approximately zero, and the relative dielectric constant of ink is greater than that of air.

[0045] An AC power supply 144 is electrically connected to the transmitting electrode 122 via a switch circuit 142. The AC power supply 144 outputs a pulse wave as a transmission signal to the transmitting electrode 122. The pulse wave is received by the receiving electrodes 131 and 133 via the air or ink in the ink tank 18 present in the capacitors 171 and 173.

[0046] Receiving electrode 131 is electrically connected to a processing unit (not shown) via wiring 141, and receiving electrode 133 is electrically connected to a processing unit (not shown) via wiring 143. The processing unit includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage circuit such as a semiconductor memory.

[0047] In the direction along the Z axis, the liquid level LV1 is the range from the bottom to the top of the capacitor 171, and the liquid level LV3 is the range from the bottom to the top of the capacitor 173. From the bottom surface 126 of the ink tank 18 in the +Z direction, the liquid level LV3 and the liquid level LV1 are arranged in this order.

[0048] When the ink level L is at either level LV1 or LV3, a difference occurs in the pulse waves received by the receiving electrodes 131, 133, in other words, the output voltages of the capacitors 171, 173. Within the corresponding range, the output voltages are large when ink is present, small when air is present, and intermediate when both ink and air are present. The output voltages in these cases are preset as three threshold values. That is, the position of the ink level L is identified by comparing the output voltages of the capacitors 171, 173 with the three threshold values ​​in the processing unit. This makes it possible to detect the amount of ink contained in the ink tank 18.

[0049] The detection unit 60 is electrically connected to the control unit of the printer 1. The detection unit 60 sends the detection result, which is the amount of ink contained in the ink storage unit 121, to the control unit. The control unit controls various operations of the printer 1 according to the ink storage amount. Examples of the various operations include the number and mass of ink droplets ejected from the inkjet head 25, and maintenance conditions related to the inkjet head 25.

[0050] The control unit may also display the ink capacity on the display unit 16 or on an information device that operates the printer 1. The control unit may also notify the user via the display unit 16 that ink is low and needs to be replenished, or that there is sufficient ink. The function of the processing unit of the detection unit 60 may be assigned to the control unit of the printer 1.

[0051] According to this embodiment, the following effects can be obtained.

[0052] Even when the printer 1 is tilted, the variation in the detected ink liquid level position can be reduced. More specifically, when the printer 1 is installed in an inclined position, the ink tank 18 also tilts, causing the ink liquid level L in the ink containing unit 121 to tilt. For example, when viewed from the side from the -X direction, if the printer 1 is installed so that it is higher in the +Y direction and lower in the -Y direction, the liquid level L will be higher at the -Y direction end of the ink containing unit 121 and lower at the +Y direction end. Furthermore, when the printer 1 is installed in the reversed position, the liquid level L will be lower at the -Y direction end of the ink containing unit 121 and higher at the +Y direction end. In this way, the liquid level L will be uneven at the ends of the ink containing unit 121 depending on the tilt of the printer 1 on which it is installed.

[0053] In contrast, the liquid level L is less likely to change in the center of the ink containing unit 121 even if the printer 1 is tilted. Therefore, the detection unit 60 located in the center of the ink containing unit 121 is less likely to detect variations in the liquid level position. This makes it possible to provide an ink tank 18 that reduces variations in the detected liquid level position depending on the installation position of the printer 1.

[0054] Since the filter unit 113 and the detection unit 60 are arranged along the Z axis, the distance between them is shortened. Therefore, compared to when the filter unit 113 and the detection unit 60 are arranged far apart, it is possible to accurately detect a state where the remaining ink amount is low, in which the filter unit 113 is exposed above the ink liquid level L.

[0055] The provision of the visual confirmation portion 61 makes it possible to visually confirm the ink level position in the ink containing portion 121. Furthermore, when refilling the ink containing portion 121 with ink while visually checking the ink level L at the visual confirmation portion 61, it is possible to prevent overfilling of ink.

[0056] More specifically, when the printer 1 is installed in the above-described position, the ink level L in the ink containing unit 121 tilts. At this time, because the visible portion 61 and the inlet 111 are both located at the end of the ink containing unit 121 in the -Y direction, a correlation occurs between the ink level position visible through the visible portion 61 and the amount of ink that can be replenished into the ink containing unit 121. Therefore, by adjusting the amount of ink to be replenished according to the visible liquid level position, excessive refilling of ink can be avoided. This prevents overfilling of ink and prevents ink from spilling from the ink tank 18.

[0057] 2. Second embodiment The ink tank according to this embodiment is mounted in the printer 1 in the same manner as the ink tank 18 of the first embodiment.

[0058] As shown in Fig. 5, the ink tank 28 according to this embodiment includes an inlet 211, an ink storage section 121, a detection section 60, a visual confirmation section 61, a filter section 113, and a supply section 115. The housing of the ink tank 28 is substantially cubic. Note that Fig. 5 does not show the ink flow path from the filter section 113 to the supply section 115.

[0059] The ink tank 28 has a different arrangement of the filler port 211 from the ink tank 18 of the first embodiment. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0060] An inlet 211 is provided on the top surface 127 of the ink containing section 121. More specifically, the inlet 211 is disposed in the +Z direction of the detection section 60. In other words, when the printer 1 equipped with the ink tank 28 is placed on a horizontal surface, the inlet 211 is disposed in the direction opposite to the vertical direction, which is the first direction, relative to the detection section 60.

[0061] The inlet 211 is, for example, a tubular member whose tip in the +Z direction protrudes from the top surface 127 and whose tip in the -Z direction communicates with the inside of the ink containing section 121. Ink is replenished into the ink containing section 121 through the inlet 211. Because the inlet 211 is disposed on the top surface 127, ink can be poured from the inlet 211 into the ink containing section 121 by gravity. The inlet 211 may have a cap or the like at its tip in the +Z direction.

[0062] According to this embodiment, the following effects can be obtained in addition to the effects of the first embodiment.

[0063] The detected ink volume can be used to prevent the user from overfilling the ink storage unit 121 when refilling the ink storage unit 121. Specifically, if the printer 1 is installed in an inclined position, the ink tank 28 also inclines, causing the ink level L in the ink storage unit 121 to tilt. In this case, the ink level position is less likely to change in the center of the ink storage unit 121 in the direction along the Y axis, making it less likely that the ink level position detected by the detection unit 60 will vary.

[0064] Furthermore, since the inlet 211 is disposed in the +Z direction at the center of the ink containing section 121, a correlation occurs between the detected ink capacity and the amount of ink that can be replenished to the ink containing section 121. Therefore, excessive ink replenishment can be avoided by adjusting the amount of ink to be replenished according to the ink capacity. This prevents overfilling of ink and prevents ink from spilling from the ink tank 28.

[0065] 3. Working Example The effects of the above-described embodiments will be explained more specifically with reference to examples. As examples, the ink tank 18 of the first embodiment and the ink tank 28 of the second embodiment will be exemplified. As comparative examples, the ink tanks 38, 48, 58, 68, and 78 will be exemplified.

[0066] 6, in the ink tank 18, the detection unit 60 is disposed at the center of the ink containing unit 121 in the direction along the Y axis. The filter unit 113 is disposed on the -Z side of the detection unit 60. The filler port 111 is disposed on the -Y and +Z sides of the ink containing unit 121. The viewing unit 61 is disposed on the -Y side of the housing of the ink tank 18.

[0067] 7, in the ink tank 28, the detection unit 60 is disposed in the center of the ink containing section 121 in the direction along the Y axis. The filter section 113 is disposed on the −Z side of the detection unit 60. The injection port 211 is disposed on the +Z side of the detection unit 60. The viewing unit 61 is disposed on the −Y side of the housing of the ink tank 28.

[0068] 8, in the ink tank 38, the detection unit 60 is disposed at the end of the ink containing unit 121 in the -Y direction. The filter unit 113 is disposed on the -Z side of the detection unit 60. The injection port 111 is disposed on the +Z side of the detection unit 60. The viewing unit 61 is disposed on the -Y side of the housing of the ink tank 38.

[0069] 9, in the ink tank 48, the detection unit 60 is disposed at the end of the ink containing unit 121 in the -Y direction. The filter unit 113 is disposed on the -Z side of the detection unit 60. In the ink containing unit 121, the filler port 211 is disposed on the +Z side of the center in the direction along the Y axis. The visual confirmation unit 61 is disposed on the -Y side of the housing of the ink tank 48.

[0070] 10, in the ink tank 58, the detection unit 60 is disposed at the end of the ink containing section 121 in the -Y direction. The filter unit 113 is disposed at the end of the ink containing section 121 in the +Y direction and in the -Z direction. The filler port 111 is disposed in the +Z direction of the detection unit 60. The viewing unit 61 is disposed in the -Y direction of the housing of the ink tank 58.

[0071] 11, in the ink tank 68, the detection unit 60 is disposed at the end of the ink containing section 121 in the -Y direction. The filter section 113 is disposed on the -Z side of the detection unit 60. The filler port 111 is disposed on the +Y and +Z sides of the ink containing section 121. The visual confirmation unit 61 is disposed on the -Y side of the housing of the ink tank 68.

[0072] As shown in Figure 12, in the ink tank 78, the detection unit 60 is located at the end of the ink containing section 121 in the +Y direction. The filter section 113 is located on the -Z side of the detection unit 60. The filler port 111 is located on the -Y and +Z sides of the ink containing section 121. The visual confirmation unit 61 is located on the -Y side of the housing of the ink tank 78. That is, when viewed through from the -X direction, in the direction along the Y axis of the ink containing section 121, the detection unit 60 and the filter section 113 are located at the end of the +Y direction, and the filler port 111 and the visual confirmation unit 61 are located at the end of the -Y direction.

[0073] 6 to 12, when the printer 1 is placed on a horizontal surface, region b is detected as having sufficient ink in the ink storage unit 121, and region c is detected as having no ink. Region a is the range into which ink can be added after the state in which the detection unit 60 detects that there is sufficient ink. When the printer 1 is placed on a horizontal surface, regions a, b, and c are equivalent for each of the ink tanks 18 to 78. Note that configurations other than those described above are omitted from FIGS. 6 to 12.

[0074] Below, we will explain the effects of tilting ink tanks 18 to 78 in the rotation direction around the rotation axis that is a straight line along the X-axis. Of the figures referenced below, those with an A at the end of their figure numbers show a state in which the rotation direction is counterclockwise and the -Y end is tilted upward when viewed from the side from the -X direction. Furthermore, those with a B at the end of their figure numbers show a state in which the rotation direction is clockwise and the +Y end is tilted upward when viewed from the side from the -X direction.

[0075] Furthermore, in the figures referred to below, some of the configurations shown in Figures 6 to 12 are omitted, and the G axis is added as an additional coordinate axis to the X, Y, and Z axes. On the G axis, the direction indicated by the arrow coincides with the vertical direction. In addition, the following explanation will describe each ink tank as seen through from the -X direction, unless otherwise specified.

[0076] 3.1. Detector and filter arrangement The influence of tilt on the arrangement of the detection section 60 and the filter section 113 will now be described.

[0077] When the amount of ink contained in the ink containing section 121 decreases, the detection section 60 detects that there is no ink. At this time, ink still remains in the vertical direction of the detection section 60. This is the region c of ink remaining when no ink is detected as described above. Note that this region will hereinafter be simply referred to as no-ink detection region c.

[0078] When the detection unit 60 detects that there is no ink left, the printer 1 uses ink in the no-ink detection area c through software control by the control unit. Specifically, the control unit estimates the amount of ink contained in the ink storage unit 121 from data on the amount of ink droplets ejected by the inkjet head 25 and the amount of ink consumed during cleaning of the inkjet head 25, and continues operating the printer 1.

[0079] If ink continues to be used in the no-ink detection area c, the ink capacity will become very small. If ink continues to be used, the filter section 113 will be exposed to the air. If the filter section 113 is exposed to the air, air will flow into the inkjet head 25, causing malfunctions. Therefore, the control unit stops the use of ink in the ink storage section 121, leaving some ink to prevent the filter section 113 from being exposed to the air.

[0080] Therefore, in order to reduce the amount of unused ink remaining and prevent the filter unit 113 from being exposed to the air, it was necessary to reduce variations in the ink capacity when an out-of-ink state was detected due to the tilt of the printer 1. In the following explanation, the remaining ink area immediately before the filter unit 113 is exposed to the air is referred to as the pre-filter exposure area e.

[0081] As shown in Figures 13A and 13B, in the ink tanks 18 and 28, the detection unit 60 and the filter unit 113 are both positioned in the center of the ink containing unit 121 in the direction along the Y axis. This reduces the difference between the ink capacity of the no-ink detection area c1 and the ink capacity of the no-ink detection area c2. This reduces the detection variation in the ink capacity when detecting an ink shortage. This also reduces the difference between the ink capacity of the pre-filter exposure area e1 and the ink capacity of the pre-filter exposure area e2.

[0082] 14A and 14B, in the ink tanks 38, 48, and 68, the detection unit 60 and the filter unit 113 are both located at one end of the ink containing unit 121. This increases the difference between the ink capacity of the no-ink detection area c3 and the ink capacity of the no-ink detection area c4, increasing the detection variability of the ink capacity when detecting an ink shortage. This also increases the difference between the ink capacity of the pre-filter exposure area e3 and the ink capacity of the pre-filter exposure area e4.

[0083] For these reasons, by locating the detection unit 60 and the filter unit 113 in the center along the Y axis, the detection accuracy of the ink capacity when detecting an out-of-ink state is improved. Also, because the difference in the ink capacity between the pre-filter exposure areas e1 and e2 is reduced, the amount of ink left as a surplus in the ink storage unit 121 can be reduced.

[0084] 3.2. Positioning of the filter unit relative to the detection unit The influence of the inclination in the arrangement of the filter section 113 relative to the detection section 60 will be described.

[0085] 15A and 15B, in the ink tank 58, the detection unit 60 is located at one end of the ink containing section 121 in the direction along the Y axis, and the filter section 113 is located at the other end. Because the detection unit 60 and the filter section 113 are located at a distance from each other, depending on the inclination of the ink tank 58, the ink capacity of the no-ink detection area c4 may be smaller than the ink capacity of the pre-filter exposure area e6. In other words, there is a risk that the filter section 113 will be exposed earlier than the no-ink detection is performed.

[0086] 14A and 14B, in ink tanks 38, 48, and 68, the detection unit 60 and filter unit 113 are located at the one end, which reduces the risk of the filter unit 113 becoming exposed earlier than the out-of-ink detection. Furthermore, in the ink tanks 18 and 28 described above, this risk is even smaller.

[0087] From the above, by arranging the filter section 113 in the −Z direction with respect to the detection section 60, exposure of the filter section 113 to the air can be suppressed.

[0088] 3.3. Detector placement The following describes the influence of tilt on the placement of the detection unit 60. Here, the lower limit of the liquid level of the area where the detection unit 60 detects that there is a sufficient amount of ink in the ink containing unit 121 is set to Lb.

[0089] 13A and 13B, in the ink tanks 18 and 28, the detection unit 60 is located in the center of the ink containing section 121 in the direction along the Y axis. This reduces the difference between the liquid level Lb1 and the liquid level Lb2. In other words, when the ink containing section 121 contains a sufficient amount of ink, the variation in the detection of the liquid level position decreases.

[0090] 14A and 14B, in the ink tanks 38, 48, and 68, the detection unit 60 is located at the end of the ink containing section 121 in the direction along the Y axis, which increases the difference between the liquid level Lb3 and the liquid level Lb4. In other words, when the ink containing section 121 contains a sufficient amount of ink, the variation in the detection of the liquid level position increases.

[0091] From the above, by positioning the detection unit 60 in the center of the ink storage unit 121 in the direction along the Y axis, the detection accuracy of the ink storage amount can be improved when the ink storage unit 121 has a sufficient ink storage amount.

[0092] 3.4. Positioning of the injection port relative to the detection unit The influence of the inclination in the arrangement of the injection ports 111 and 211 relative to the detection unit 60 will be described.

[0093] Even if the ink level is at level Lb, there is space in the +Z direction of the ink storage section 121, making it possible to add more ink. In this case, if the amount of ink that can be added varies greatly depending on the tilt of the printer 1, there is a risk that too much ink will be added, causing the ink to overflow.

[0094] 16A and 16B, in ink tank 28, region k1 is defined as the area from liquid level Lb1 to the tip of filler port 211 in the -Z direction, and region k2 is defined as the area from liquid level Lb2 to the tip of filler port 211 in the -Z direction. In other words, as long as the area does not exceed regions k1 and k2, ink will not overflow even if ink is added.

[0095] In the ink tank 28, the detection unit 60 is disposed in the center of the ink containing section 121 in the direction along the Y axis, and the inlet 211 is disposed in the +Z direction of the detection unit 60. This reduces the difference between the area k1 and the area k2. In other words, when ink is added to the ink containing section 121 beyond the liquid levels Lb1 and Lb2, ink overflow is suppressed.

[0096] 17A and 17B, in ink tank 18, region k3 is the area from liquid level Lb1 to the tip of filler port 111 in the -Z direction, and region k4 is the area from liquid level Lb2 to the tip of filler port 111 in the -Z direction. If the area does not exceed regions k3 and k4, ink will not overflow even if ink is added.

[0097] In the ink tank 18, the detection unit 60 is located in the center of the ink containing section 121 in the direction along the Y axis, and the inlet 111 is located in the +Z direction at the end in the -Y direction. Area k4 is smaller than area k3, and the difference between area k3 and area k4 is large. In other words, when ink is added to the ink containing section 121 beyond the liquid levels Lb1 and Lb2, ink is more likely to overflow.

[0098] From the above, by arranging the detection unit 60 in the center of the ink storage unit 121 in the direction along the Y axis and arranging the injection port 211 in the +Z direction of the detection unit 60, it is possible to prevent ink from spilling when refilling ink.

[0099] 3.5. Location of the detection and viewing units The influence of tilt on the arrangement of the detection unit 60 and the viewing unit 61 will now be described.

[0100] When the amount of ink contained in the ink storage unit 121 decreases, the detection unit 60 detects that there is no ink. At this time, ink still remains in the no-ink detection area c, which is in the vertical direction of the detection unit 60. The control unit notifies the user, via the display unit 16 or an information device that operates the printer 1, that the amount of ink contained in the ink storage unit 121 is running low.

[0101] In some cases, the user may receive the above notification and visually check the ink capacity from the visual confirmation unit 61. In this case, if the visually confirmed ink capacity varies depending on the tilt of the printer 1, this can confuse the user.

[0102] As shown in FIGS. 18A and 18B, in the ink tanks 38, 48, and 68, the visible liquid level corresponding to the no-ink detection area c3 is denoted by s1, and the visible liquid level corresponding to the no-ink detection area c4 is denoted by s2.

[0103] 18A and 18B have different tilt directions, but because the detection unit 60 and the visual confirmation unit 61 are both located at the ends along the Y axis, the difference between the liquid level height s1 and the liquid level height s2 is not very large, which reduces the possibility of the user becoming confused by the visual liquid level.

[0104] As shown in FIGS. 19A and 19B, in the ink tank 78, the visible liquid level corresponding to the no-ink detection area c5 is set to s0, and the visible liquid level corresponding to the no-ink detection area c6 is set to s3.

[0105] There is no liquid level height s0, and the user may believe that there is no ink remaining. In contrast, the liquid level height s3 is so high that it reaches almost the middle of the visual confirmation section 61, and the user may mistakenly believe that there is a sufficient amount of ink remaining, contrary to the notification. This is because the detection section 60 and the visual confirmation section 61 are located at different ends in the direction along the Y axis.

[0106] As shown in FIGS. 20A and 20B, in the ink tanks 18 and 28, the visible liquid level corresponding to the no-ink detection area c1 is denoted as s4, and the visible liquid level corresponding to the no-ink detection area c2 is denoted as s5.

[0107] Because the liquid level height s4 is low, the user may perceive that the ink capacity is small. In contrast, because the liquid level height s5 is high, the user may perceive that there is still ink capacity remaining. The difference between the liquid level heights s4 and s5 is smaller than the difference between the liquid level heights s0 and s3 described above, but is larger than the difference between the liquid level heights s1 and s2 described above. This is because, in the direction along the Y axis, the detection unit 60 is located in the center, and the visual confirmation unit 61 is located at the end in the -Y direction.

[0108] From the above, by arranging the detection unit 60 and the viewing unit 61 at the end of the ink storage unit 121 in the -Y direction along the Y axis, it is possible to reduce the variation in the ink storage amount visible at the viewing unit 61 when an ink-out state is notified.

[0109] 3.6. Location of the detection unit, viewing unit, and injection port The effect of tilt on the arrangement of the detection unit 60, the viewing unit 61, and the injection ports 111 and 211 will now be described.

[0110] Even if it is detected that the ink storage unit 121 has a sufficient ink capacity, it is possible to add ink while visually checking the ink storage amount through the visual check unit 61. In this case, if the visually checked ink storage amount differs greatly depending on the tilt of the printer 1, there is a risk that excessive ink will be added, causing the ink to spill.

[0111] 21A and 21B, in the ink tanks 38 and 58, the area b3 to which ink can be added is designated as k5, and the area b4 to which ink can be added is designated as k6. The visible liquid level corresponding to areas b3 and k5 is designated as s6, and the visible liquid level corresponding to areas b4 and k6 is designated as s7.

[0112] In the ink tanks 38 and 58, the inlet 111, the detection unit 60, and the visual confirmation unit 61 are disposed at the end of the ink containing section 121 in the -Y direction along the Y axis. This reduces the difference between the liquid level height s6 and the liquid level height s7. In other words, when ink is added to the regions k5 and k6 of the ink containing section 121, the occurrence of ink overflow is suppressed.

[0113] 22A and 22B, in the ink tank 48, the area b3 to which ink can be added is designated as k7, and the area b4 to which ink can be added is designated as k8. The visible liquid level corresponding to areas b3 and k7 is designated as s8, and the visible liquid level corresponding to areas b4 and k8 is designated as s9.

[0114] In the ink tank 48, the inlet 211 is located in the center of the ink containing section 121 in the direction along the Y axis, and the detection section 60 and the visual confirmation section 61 are located at the end in the -Y direction. This results in a large difference between the liquid level height s8 and the liquid level height s9. In other words, when ink is added to the region k7 of the ink containing section 121, ink may overflow.

[0115] 23A and 23B, in ink tank 68, it is difficult to add ink to area b3, and area b4, where ink can be added, is designated as area k9. The visible liquid level corresponding to area b3 is designated as s10, and the visible liquid level corresponding to areas b4 and k9 is designated as s11.

[0116] In the ink tank 68, in the direction along the Y axis of the ink containing section 121, the inlet 111 is located at the end in the +Y direction, and the detection section 60 and the visualization section 61 are located at the end in the -Y direction. Therefore, the difference between the liquid level height s10 and the liquid level height s11 is greater than the difference between the liquid level height s6 and the liquid level height s7. In other words, compared to the ink tanks 38 and 58, there is a possibility that ink may overflow when the ink containing section 121 is filled to the brim with ink.

[0117] From the above, by arranging the inlet 111, the detection unit 60, and the viewing unit 61 at the end in the -Y direction along the Y axis of the ink storage unit 121, it is possible to prevent ink from spilling when refilling the ink. [Explanation of symbols]

[0118] 1...printer, 18, 28...ink tank, 60...detection section, 61...visibility section, 111..., 211 inlet, 113...filter section, 115...supply section, 121...ink storage section, 129...side, L, Lb1, Lb2, Lb3, Lb4...liquid level.

Claims

1. an ink storage section that stores ink; a detection unit that detects the position of the ink surface in the ink storage unit; a supply unit that supplies the ink to the outside; an inlet for refilling the ink in the ink storage section; a filter portion disposed in the ink storage portion and interposed between the ink storage portion and the supply portion, By transillumination from the side, the filter unit is disposed in a first direction relative to the detection unit; the detection unit is disposed at a center of the ink storage unit in a longitudinal direction, which is a second direction orthogonal to the first direction, The ink tank has an inlet that is disposed in a direction opposite to the first direction with respect to the detection unit and at a center portion of the longitudinal direction of the ink containing unit, which is the second direction.

2. 2. The ink tank according to claim 1, wherein the filter portion is disposed at a center portion in a longitudinal direction of the ink containing portion, which is the second direction.

Images