Liquid leakage detecting device and ink jet recording apparatus

Abstract

To improve space efficiency inside an ink jet recorder.SOLUTION: A liquid leakage detection device provided inside an ink jet recording apparatus includes an ink detection unit in which an exposed conductor portion of a first core included in a multi-core flat cable and an exposed conductor portion of a second core included in the multi-core flat cable are configured as a pair of electrode terminals, and a detection circuit that detects that a liquid has leaked by detecting that a potential difference between the pair of electrode terminals has fallen below a predefined threshold value.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a liquid leakage detection device and an inkjet recording device. [Background technology]

[0002] Patent Document 1 describes a technology for an ink leak detection mechanism for a printer. In the technology described in Patent Document 1, a pair of electrode terminals functions as an ink detection unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-160825 Summary of the Invention [Problem to be solved by the invention]

[0004] To improve the accuracy of ink leak detection, ink detection units are installed in multiple locations inside the printer where ink leaks are likely to occur. Conventionally, each ink detection unit is individually connected to the control unit by wire. This creates the problem that the wires connecting the ink detection units to the control unit take up a large amount of space in the limited space inside the printer. For this reason, there is a need to improve the space efficiency inside the printer. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] According to one aspect of the present disclosure, there is provided a liquid leakage detection device to be installed inside an inkjet recording device, the liquid leakage detection device including: an ink detection unit configured with an exposed conductor portion of a first core included in a multi-core flat cable and an exposed conductor portion of a second core included in the multi-core flat cable as a pair of electrode terminals; and a detection circuit that detects liquid leakage by detecting when the potential difference between the pair of electrode terminals falls below a predefined threshold.

[0007] According to another aspect of the present disclosure, there is provided an inkjet recording apparatus including a liquid circulation unit, an ejection unit, a case storage unit, a control unit, and a liquid leakage detection device. The liquid leakage detection device includes an ink detection unit configured using an exposed conductor portion of a first core included in a multi-core flat cable and an exposed conductor portion of a second core included in the multi-core flat cable as a pair of electrode terminals, and a detection circuit that detects liquid leakage by detecting that the potential difference between the pair of electrode terminals falls below a predetermined threshold. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic perspective view showing the external configuration of a printing device equipped with a liquid leakage detection device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of the printing device as seen from the front side. [Figure 3] FIG. 2 is an explanatory diagram showing the circuit configuration of the liquid leakage detection device. [Figure 4] FIG. 2 is an explanatory diagram illustrating the configuration of an ink detection unit. [Figure 5] FIG. 10 is an explanatory diagram of a method for detecting the occurrence of ink leakage. [Figure 6] FIG. 10 is an explanatory diagram of a method for arranging ink detection units according to another embodiment (B2). [Figure 7] FIG. 10 is an explanatory diagram showing an example of the arrangement of a processed multi-core flat cable FC2 in another embodiment (B2). [Figure 8] FIG. 10 is an explanatory diagram showing the circuit configuration of a detection circuit in another embodiment (B5). DETAILED DESCRIPTION OF THE INVENTION

[0009] A. Implementation: FIG. 1 is a schematic perspective view showing the external configuration of a printing device 10 equipped with a liquid leakage detection device 70 according to this embodiment. An XYZ Cartesian coordinate system is set up in FIG. 1. The Z axis is aligned with the direction of gravity. The +Z direction is the direction of gravity. The Z direction corresponds to the up-down direction of the printing device 10. The X and Y axes are aligned with the horizontal plane. The Y axis is aligned with the front-to-rear direction of the printing device 10. The +Y direction corresponds to the direction from the rear to the front of the printing device 10. The X axis is aligned with the left-to-right direction of the printing device 10. The +X direction corresponds to the direction from right to left when facing the front of the printing device 10. FIG. 2 is a schematic view of the printing device 10 viewed from the front with the housing 10h and cover member 18 removed.

[0010] The printing device 10 includes a housing 10h, a liquid circulation unit 20 arranged within the housing 10h, a jetting unit 30, a medium transport unit 35, a control unit 40, and a liquid leakage detection device 70. Note that the liquid circulation unit 20, the jetting unit 30, the medium transport unit 35, the control unit 40, and the liquid leakage detection device 70 are not shown in Fig. 1. The liquid leakage detection device 70 is not shown in Fig. 2.

[0011] The printing device 10 is an inkjet printer. The printing device 10 is also called an "inkjet recording device." The printing device 10 forms an image by ejecting ink, which is an example of a liquid, and recording ink dots on a medium, such as printing paper. The medium onto which the printing device 10 ejects ink is not limited to printing paper, but may also be plastic, film, fiber, fabric, leather, metal, glass, wood, ceramics, etc.

[0012] 1, the housing 10h is a hollow, approximately rectangular parallelepiped enclosure that forms the exterior of the printing device 10. A front surface 12 of the housing 10h is provided with an operation panel 13, a medium discharge port 14, a paper discharge tray 15, a paper feed tray 16, an attachment port 17, a cover member 18, and a case storage section 19.

[0013] The operation panel 13 functions as a display unit that displays information and an input unit that accepts user operations. The operation panel 13 is, for example, a touch panel. The medium discharge port 14 is an exit for media discharged from the interior of the printing device 10. The medium discharge port 14 is formed as a slit-shaped opening that is wide in the X direction. The paper discharge tray 15 is located below the medium discharge port 14. The paper discharge tray 15 receives media discharged from the medium discharge port 14.

[0014] The paper feed tray 16 stores media. The loading slot 17 is an opening for inserting the paper feed tray 16 into the housing 10h. The loading slot 17 is formed as a generally rectangular opening that is wide in the X direction below the paper output tray 15. When replenishing media, the user places the media in the paper feed tray 16 that has been pulled out from the loading slot 17 in the +Y direction. The user then loads the paper feed tray 16 into the printing device 10 through the loading slot 17.

[0015] The cover member 18 is a plate-like member made of resin that forms part of the exterior of the printing device 10. The cover member 18 has a generally rectangular shape that is wide in the X direction. The cover member 18 is disposed below the paper feed tray 16. The cover member 18 has claws (not shown) on its outer periphery and is detachably attached to the housing 10h. The cover member 18 covers the cases S1 to S4 stored in the case storage section 19.

[0016] The case storage section 19 is a space formed inside the housing 10h for storing the cases S1 to S4. The cases S1 to S4 are configured as tray-shaped containers. The cases S1 to S4 are used to mount the ink cartridges IC1 to IC4 in the printing device 10. The cases S1 to S4 are arranged in the X direction in the case storage section 19. The cases S1 to S4 are mounted in the printing device 10 with the ink cartridges IC1 to IC4 housed inside. The ink cartridges IC1 to IC4 are so-called ink packs. The ink cartridges IC1 to IC4 store black, cyan, magenta, and yellow ink, respectively. When setting the ink cartridges, the user places the ink cartridges in the case that has been pulled out in the +Y direction. The user then inserts the case into the case storage section 19.

[0017] As shown in FIG. 2, the liquid circulation unit 20 includes a plurality of tubes 21, a plurality of circulation pipes 22, and a pump 25. The plurality of tubes 21 are arranged in the Y direction. The plurality of tubes 21 are connected to the print head 31. The plurality of tubes 21 are connected to a plurality of circulation pipes 22. When the pump 25 is operated, the ink inside the ink cartridges IC1 to IC4 is pushed out into the circulation pipes 22. The ink in the ink cartridges IC1 to IC4 is supplied to the print head 31 via the circulation pipes 22 and the tubes 21.

[0018] The ejection execution unit 30 includes a print head 31 and a carriage 34. The print head 31 receives ink supply via multiple tubes 21 of the liquid circulation unit 20. The print head 31 includes nozzles N that eject ink supplied from the liquid circulation unit 20 downward. The print head 31 moves together with the carriage 34, and ejects ink supplied from ink cartridges IC1 to IC4 onto the medium. The carriage 34 carries the print head 31, and is moved back and forth in the X direction, which is the main scanning direction, by a drive mechanism (not shown).

[0019] The medium transport unit 35 transports the medium M in the sub-scanning direction under the control of the control unit 40. The sub-scanning direction is the Y direction. The medium transport unit 35 includes transport rollers 36 that are installed in the X direction below the print head 31. A paper feed tray 16 is disposed below the transport rollers 36.

[0020] When the printing process is executed, the control unit 40 transports the medium M in the sub-scanning direction using the medium transport unit 35. Furthermore, the control unit 40 causes the carriage 34 to move the print head 31 back and forth in the main scanning direction along the transport roller 36 above the transport roller 36. The control unit 40 causes the print head 31 to eject ink droplets onto the printing surface of the medium M at timing determined based on the print data. Thus, ink dots are recorded on the medium M being transported by the medium transport unit 35 at positions determined based on the print data, and an image based on the print data is formed.

[0021] FIG. 3 is an explanatory diagram showing the circuit configuration of a liquid leakage detection device 70 provided inside the printing device 10. FIG. 4 is an explanatory diagram showing the configuration of the ink detection unit. The liquid leakage detection device 70 detects ink leakage inside the printing device 10. As shown in FIG. 3, the liquid leakage detection device 70 has a first ink detection unit 100, a second ink detection unit 200, and a detection circuit 300.

[0022] The first ink detection unit 100 and the second ink detection unit 200 detect ink leakage inside the printing device 10. As shown in FIG. 4, the first ink detection unit 100 and the second ink detection unit 200 are configured using a multi-core flat cable FC. A flexible flat cable (hereinafter, FFC) is used as the multi-core flat cable FC. An FFC is formed by sandwiching a parallel arrangement of conductive electric wires between flexible insulating films from above and below and crimping the wires. The multi-core flat cable FC has a first core 110, a second core 120, a third core 130, and a fourth core 140.

[0023] The first ink detection unit 100 is composed of an electrode terminal 111, which is an exposed conductor portion of the first core 110, and an electrode terminal 121, which is an exposed conductor portion of the second core 120. The electrode terminals 111 and 121 are provided near one end of the multi-core flat cable FC. The first core 110 and the second core 120 are adjacent to each other. No other cores exist between the first core 110 and the second core 120. The electrode terminals 111 and 121 are also referred to as a "pair of electrode terminals." The electrode terminal 111 is formed by exposing a portion of the first core 110. A portion of the first core 110 is exposed by removing a portion of the insulating film covering the first core 110. The same is true for the other electrode terminals. The electrode terminal 121 is formed by exposing a portion of the second core 120. The first ink detection unit 100 is also referred to as an "ink detection unit." The electrode terminal 111 is also referred to as a "first electrode terminal." The electrode terminal 121 is also called a "second electrode terminal."

[0024] The second ink detection unit 200 is composed of an electrode terminal 131, which is an exposed conductor portion of the third core 130, and an electrode terminal 141, which is an exposed conductor portion of the fourth core 140. The third core 130 and the fourth core 140 are adjacent to each other. No other cores exist between the third core 130 and the fourth core 140. The second core 120 is adjacent to the third core 130 on the side opposite to the side adjacent to the first core 110. No other cores exist between the second core 120 and the third core 130. The electrode terminals 131 and 141 are also referred to as "another pair of electrode terminals." The electrode terminal 131 is formed by exposing a portion of the third core 130. The electrode terminal 141 is formed by exposing a portion of the fourth core 140. The electrode terminals 131 and 141 are provided in the middle region of the multi-core flat cable FC. The intermediate region of the multi-core flat cable FC includes a portion including the longitudinal midpoint of the multi-core flat cable FC, but does not include both end portions of the multi-core flat cable FC. On the other hand, the electrode terminals 111 and 121 are provided at the end portion on the -X side of the multi-core flat cable FC. The end portion of the multi-core flat cable FC includes a portion including the longitudinal end edge of the multi-core flat cable FC. Furthermore, the electrode terminals 111, 121, 131, and 141 are provided on the same surface of the multi-core flat cable FC. The electrode terminal 131 is also referred to as the "third electrode terminal." The electrode terminal 141 is also referred to as the "fourth electrode terminal."

[0025] The multi-core flat cable FC is disposed, for example, in the case storage unit 19 (see FIG. 2 ) below the portion connecting the case S1 and the liquid circulation unit 20, with the longitudinal direction of the multi-core flat cable FC aligned with the X-axis direction. In this case, the multi-core flat cable FC is disposed so that the electrode terminals 111 and 121 and the electrode terminals 131 and 141 face the bottom surface of the case storage unit 19. As described above, the electrode terminals 111 and 121 are provided near one end of the multi-core flat cable FC, and the electrode terminals 131 and 141 are provided in the middle region of the multi-core flat cable FC. Therefore, the second ink detection unit 200 formed by the electrode terminals 131 and 141 is disposed at a position away from the first ink detection unit 100 formed by the electrode terminals 111 and 121 in the direction in which the cores extend. In addition, being located near one end of the multi-core flat cable FC means, in the example shown in Figure 4, being located closer to the electrodes EL7 to EL10 at the -X side end of the multi-core flat cable FC in the area between the electrodes EL7 to EL10 at the -X side end and the electrode terminals 131 and 141.

[0026] The detection circuit 300 shown in Fig. 3 detects ink leakage inside the printing device 10 by detecting a short circuit between the electrode terminals 111 and 121 or a short circuit between the electrode terminals 131 and 141. Because ink is a conductor, if ink leaks near the electrode terminals 111 and 121, the ink will short circuit the terminals of the electrode terminals 111 and 121. The same applies to a short circuit between the terminals of the electrode terminals 131 and 141. The detection circuit 300 is provided on the control board 300B. The control board 300B is disposed inside the control unit 40, for example.

[0027] Electrodes EL1 to EL4 (see FIG. 4) at the +X side end of the multi-core flat cable FC are electrically connected to the control board 300B by a connector (not shown) that corresponds to a four-core FFC provided on the control board 300B.

[0028] 3 includes a first leakage signal terminal 301, a first ground terminal 302, a second leakage signal terminal 303, a second ground terminal 304, a pull-up resistor 305, a comparator 306, a resistor R1, a capacitor C1, and a power supply Vdd1. Note that in this embodiment, the four electrodes at the -X side end of the multi-core flat cable FC are not used.

[0029] The first leakage signal terminal 301 and the second leakage signal terminal 303 are connected to one end of a pull-up resistor 305. The first leakage signal terminal 301 is connected to an electrode EL1 of the first core 110 via a connector. The second leakage signal terminal 303 is connected to an electrode EL3 of the third core 130 via a connector. The other end of the pull-up resistor 305 is connected to a power supply Vdd1. The potential of the power supply Vdd1 is set to the high-potential side signal potential. A constant voltage is applied to the first leakage signal terminal 301 and the second leakage signal terminal 303 from the power supply Vdd1 via the pull-up resistor 305. This fixes the potentials of the first leakage signal terminal 301 and the second leakage signal terminal 303. The first leakage signal terminal 301 and the second leakage signal terminal 303 are connected to the positive input terminal of a comparator 306 via an RC circuit formed by a resistor R1 and a capacitor C1. The resistor R1 and the capacitor C1 are provided to output the time integral of the input to the first leakage signal terminal 301 to the comparator 306.

[0030] The first ground terminal 302 is connected via a connector to an electrode EL2 of the second core 120. The second ground terminal 304 is connected via a connector to an electrode EL4 of the fourth core 140. The first ground terminal 302 and the second ground terminal 304 are grounded.

[0031] Signals are input to the positive input terminal of the comparator 306 from the first leakage signal terminal 301 and the second leakage signal terminal 303. The negative input terminal of the comparator 306 is signal grounded. The potential at the signal ground point is set to the reference potential Vref1. The reference potential Vref1 is a low-potential potential. If the potential of the signal input to the positive input terminal of the comparator 306 is lower than the reference potential Vref1, the comparator 306 outputs a Low signal as the output Vink_leak. If the potential of the signal input to the positive input terminal of the comparator 306 is higher than the reference potential Vref1, the comparator 306 outputs a Hi signal as the output Vink_leak. The output Vink_leak of the comparator 306 is input to a processor (not shown) that has an interface capable of accepting digital signals. Upon receiving the Low signal as the output Vink_leak, the processor (not shown) can detect that ink leakage has occurred in the first ink detection unit 100 or the second ink detection unit 200. Also, for example, a processor (not shown) can notify a user that an ink leak has been detected.

[0032] 5 is an explanatory diagram of a method for detecting ink leakage. Here, it is assumed that ink leakage has occurred near the electrode terminals 131 and 141 that make up the second ink detection unit 200. Ink leakage refers to ink leaking from inside the ink cartridges IC1 to IC4, the liquid circulation unit 20, etc.

[0033] If leaked ink shorts the electrode terminals 131 and 141, a short-circuit current It flows between the electrode terminals 131 and 141. This causes a voltage drop in the third core 130, lowering the potential of the input signal to the positive input terminal of the comparator 306. When this voltage drop causes the potential of the input signal to the positive input terminal of the comparator 306 to fall below the reference potential Vref1, the comparator 306 outputs a Low signal as the output Vink_leak. This decrease in the potential of the input signal to the positive input terminal of the comparator 306 below the reference potential Vref1 indicates that at least one of the potential difference between the electrode terminals 131 and 141 and the potential difference between the electrode terminals 111 and 121 has fallen below a predetermined threshold. In this case, the comparator 306 outputs a Low signal as the output Vink_leak. In this way, ink leakage within the printing device 10 can be detected with a simple configuration.

[0034] Figure 5 shows an example in which ink leakage occurs near electrode terminals 131 and 141, but if a short circuit occurs between electrode terminals 111 and 121 due to leaked ink, a voltage drop will similarly occur in first core 110, and comparator 306 will output a Low signal as output Vink_leak.

[0035] In this embodiment, the exposed conductor portion of the core included in the multi-core flat cable FC is used as the ink detection unit. In the configuration of this embodiment, the ink detection unit occupies less space inside the printer than when each ink detection unit and the control unit are individually connected by wires. This improves the space efficiency inside the printer. Furthermore, multiple ink detection units can be easily configured using the multi-core flat cable FC. Because the configuration of the liquid leakage detection device 70 is simple, it is easy to install the liquid leakage detection device 70 in various models of printing devices.

[0036] In this embodiment, the electrode terminals 111 and 121 are provided near one end of the multi-core flat cable FC. On the other hand, the electrode terminals 131 and 141 are provided in the middle region of the multi-core flat cable FC. In this way, the ink detection unit can be placed at any desired location, not just near the end of the multi-core flat cable FC.

[0037] In addition, in this embodiment, since there is no need to mount components on the ink detection unit, an FFC is used as a multi-core flat cable FC to configure the ink detection unit, which reduces costs.

[0038] B. Other Embodiments: (B1) In the above embodiment, an example was described in which the liquid leakage detection device 70 had two ink detection units. For example, by using an FFC with six cores, the liquid leakage detection device 70 could be provided with three ink detection units. Also, by using an FFC with eight cores, the liquid leakage detection device 70 could be provided with four ink detection units. For example, four ink detection units could be disposed near the connection between the ink cartridges IC1 to IC4 and the liquid flow unit 20. In this way, the number of ink detection units can be increased or decreased depending on the number of locations where liquid leakage is desired to be detected, providing a high degree of freedom in the placement of the liquid leakage detection device 70 inside the printing device 10.

[0039] (B2) Figures 6 and 7 are explanatory diagrams illustrating a method of arranging an ink detection unit according to another embodiment (B2). Figure 6 shows how a multi-core flat cable FC2 having six cores is processed. Figure 7 shows an example of the arrangement of the processed multi-core flat cable FC2. Electrodes at both ends of the multi-core flat cable FC2 are formed on the same surface. In the multi-core flat cable FC2, a first core 110, a second core 120, a third core 130, a fourth core 140, a fifth core 150, and a sixth core 160 are arranged in this order. A liquid leakage detection device 70 according to another embodiment (B2) has a first ink detection unit 100, a second ink detection unit 200, a detection circuit 300, and a third ink detection unit 400. The first ink detection unit 100, the second ink detection unit 200, and the third ink detection unit 400 are arranged, for example, in the case storage unit 19 (see FIG. 2) below the portion that connects the case S1 and the liquid circulation unit 20. FIG. 7 shows an example in which the multi-core flat cable FC2 is divided into pairs of adjacent cores and then bent and arranged so that the first ink detection unit 100, the second ink detection unit 200, and the third ink detection unit 400 can be arranged in desired positions.

[0040] The first ink detection unit 100 is composed of an electrode terminal 111 and an electrode terminal 121 of the second core 120. The electrode on the -X side of the first core 110 in FIG. 6 is used as the electrode terminal 111. The electrode on the -X side of the second core 120 in FIG. 6 is used as the electrode terminal 121. Unlike the above embodiment, since existing electrodes are used, the effort of removing the insulating film can be avoided. The second ink detection unit 200 is composed of an electrode terminal 131 and an electrode terminal 141. The electrode on the -X side of the third core 130 in FIG. 6 is used as the electrode terminal 131. The electrode on the -X side of the fourth core 140 in FIG. 6 is used as the electrode terminal 141.

[0041] The third ink detection unit 400 is composed of an electrode terminal 151 and an electrode terminal 161. The electrode on the -X side of the fifth core 150 in FIG. 6 is used as the electrode terminal 151. The electrode on the -X side of the sixth core 160 in FIG. 6 is used as the electrode terminal 161. In addition, the electrodes EL1 to EL6 on the +X side of the multi-core flat cable FC2 are electrically connected to the control board 300B by a connector (not shown) that corresponds to a 6-core FFC provided on the control board 300B.

[0042] In another embodiment (B2), a crack is formed in the multi-core flat cable FC2 from the end on the -X side of the multi-core flat cable FC2 shown in Fig. 6 along the space between the cores. Specifically, a crack is formed along the space between the cores of the second core 120 and the third core 130. Also, a crack is formed along the space between the cores of the fourth core 140 and the fifth core 150. In the example shown in Fig. 7, a crack is formed in the multi-core flat cable FC2 up to near the electrodes EL1 to EL6 on the +X side of the multi-core flat cable FC2. However, the crack is formed in the multi-core flat cable FC2 so that the cores do not completely separate from each other.

[0043] 7, the first core 110 and the second core 120 are bent, and the third core 130 and the fourth core 140 are arranged in a bent state. Therefore, the first core 110 and the second core 120 extend in the −X direction, and the third core 130 and the fourth core 140 extend in the +X direction. In other words, the first core 110 and the second core 120 extend in a direction different from the direction in which the third core 130 and the fourth core 140 extend.

[0044] 7, the fifth core 150 and the sixth core 160 are bent so that the electrode terminals 151 and 161 constituting the third ink detection unit 400 are positioned between the first ink detection unit 100 constituted by the first core 110 and the second core 120 and the second ink detection unit 200 constituted by the third core 130 and the fourth core 140. This allows the first ink detection unit 100, the second ink detection unit 200, and the third ink detection unit 400 to be spaced apart in the X-axis direction. In this way, the first ink detection unit 100 constituted by the electrode terminals 111 and 112, the second ink detection unit 200 constituted by the electrode terminals 131 and 141, and the third ink detection unit 400 constituted by the electrode terminals 151 and 161 are positioned at a distance from one another inside the printing device 10.

[0045] (B3) The electrodes EL1 to EL4 of the multi-core flat cable FC do not necessarily have to be electrically connected directly to the control board 300B. "Electrically connected directly" means that they are connected using a cable, harness, etc., without going through another component. The electrodes EL1 to EL4 may be connected to the control board 300B using a cable, harness, etc.

[0046] (B4) In the above embodiment, an example was described in which the comparator 306 was used to detect the occurrence of a short circuit between a pair of electrode terminals. Alternatively, an A / D converter may be used instead of the comparator 306.

[0047] (B5) In the above embodiment, an example was described in which one comparator 306 provided in the detection circuit 300 detects a short circuit in the first ink detection unit 100 or the second ink detection unit 200. Alternatively, the detection circuit 300 may include one comparator for each ink detection unit.

[0048] Fig. 8 is an explanatory diagram showing the circuit configuration of a detection circuit 300a in another embodiment (B5). The detection circuit 300a shown in Fig. 8 includes a first leakage signal terminal 301, a first ground terminal 302, a second leakage signal terminal 303, a second ground terminal 304, a pull-up resistor 305, a comparator 306, a pull-up resistor 307, a comparator 308, a resistor R1, a resistor R2, a capacitor C1, a capacitor C2, a power supply Vdd1, and a power supply Vdd2.

[0049] The first leakage signal terminal 301 is connected to one end of a pull-up resistor 305. The first leakage signal terminal 301 is connected to an electrode EL1 of the first core 110 via a connector. The other end of the pull-up resistor 305 is connected to a power supply Vdd1. The potential of the power supply Vdd1 is set to the high-potential side signal potential. A constant voltage is applied to the first leakage signal terminal 301 from the power supply Vdd1 via the pull-up resistor 305. This fixes the potential of the first leakage signal terminal 301. The first leakage signal terminal 301 is connected to the positive input terminal of a comparator 306 via an RC circuit formed by a resistor R1 and a capacitor C1. The first ground terminal 302 is connected to an electrode EL2 of the second core 120 via a connector. The first ground terminal 302 is grounded.

[0050] A signal is input from the first leakage signal terminal 301 to the positive input terminal of the comparator 306. The negative input terminal of the comparator 306 is signal grounded. The potential at the signal ground point is set to reference potential Vref1. Reference potential Vref1 is a low-potential potential. If the potential of the signal input to the positive input terminal of the comparator 306 is lower than reference potential Vref1, the comparator 306 outputs a Low signal as output Vink_leak. If the potential of the signal input to the positive input terminal of the comparator 306 is higher than reference potential Vref1, the comparator 306 outputs a Hi signal as output Vink_leak. The output Vink_leak of the comparator 306 is input to a processor (not shown) that has an interface capable of accepting digital signals. Upon receiving the Low signal as output Vink_leak, the processor (not shown) can detect that ink leakage has occurred in the first ink detection unit 100.

[0051] The second leakage signal terminal 303 is connected to one end of a pull-up resistor 307. The second leakage signal terminal 303 is connected to an electrode EL3 of the third core 130 via a connector. The other end of the pull-up resistor 307 is connected to a power supply Vdd2. The potential of the power supply Vdd2 is set to the high-potential side signal potential. A constant voltage is applied to the second leakage signal terminal 303 from the power supply Vdd1 via the pull-up resistor 307. This fixes the potential of the second leakage signal terminal 303. The second leakage signal terminal 303 is connected to the positive input terminal of a comparator 308 via an RC circuit formed by a resistor R2 and a capacitor C2. The second ground terminal 304 is connected to an electrode EL4 of the fourth core 140 via a connector. The second ground terminal 304 is grounded.

[0052] A signal is input from the second leakage signal terminal 303 to the positive input terminal of the comparator 308. The negative input terminal of the comparator 308 is signal grounded. The potential at the signal ground point is set as the reference potential Vref2. The reference potential Vref2 is a low-potential potential. The reference potentials Vref1 and Vref2 may be the same or different. If the potential of the signal input to the positive input terminal of the comparator 308 is lower than the reference potential Vref2, the comparator 308 outputs a Low signal as the output Vink_rleak2. If the potential of the signal input to the positive input terminal of the comparator 308 is higher than the reference potential Vref2, the comparator 308 outputs a Hi signal as the output Vink_leak2. The output Vink_leak2 of the comparator 308 is input to a processor (not shown) equipped with an interface capable of accepting digital signals. Upon receiving the Low signal as the output Vink_leak2, the processor (not shown) can detect the occurrence of ink leakage in the second ink detection unit 200. In the above embodiment, it is not possible to determine whether ink leakage has been detected in the first ink detection unit 100 or the second ink detection unit 200. However, in another embodiment (B5), it is possible to determine whether ink leakage has been detected in the first ink detection unit 100 or the second ink detection unit 200.

[0053] Also, the comparators 306 and 308 in FIG. 8 may be replaced with A / D converters.

[0054] (B6) For example, if the first ink detection unit 100 is placed in the case housing 19 so that the electrode terminals 111 and 121 face the bottom surface of the case housing 19, a liquid absorbent material may be placed at the position on the bottom surface of the case housing 19 where the electrode terminals 111 and 121 are placed. The liquid absorbent material is a porous material formed into a plate shape. Similarly, a liquid absorbent material may be placed at the position where the second ink detection unit 200 is placed.

[0055] (B7) In another embodiment (B2), an example was described in which the first ink detection unit 100, the second ink detection unit 200, and the third ink detection unit 400 were arranged below the portion connecting the case and the liquid circulation unit 20. However, the first ink detection unit 100, the second ink detection unit 200, and the third ink detection unit 400 do not have to be arranged along the same plane. For example, the first ink detection unit 100, the second ink detection unit 200, and the third ink detection unit 400 may be arranged around the print head 31, below the carriage 34, below the pump 25, etc.

[0056] (B8) In the above embodiment, an example was described in which the electrode terminals 111, 121, 131, and 141 were provided on the same surface of the multi-core flat cable FC. However, the electrode terminals 111 and 121 that make up the first ink detection unit 100 and the electrode terminals 131 and 141 that make up the second ink detection unit 200 may be provided on different surfaces of the multi-core flat cable FC.

[0057] (B9) In the other embodiment (B2), an example has been described in which all of the mutually separated core pairs are bent, but it is also possible to bend only some of the core pairs.

[0058] (B10) In the alternative embodiment (B2), an example was described in which adjacent cores are paired to form one ink detection unit. However, the cores constituting one ink detection unit do not have to be adjacent. For example, in a multi-core flat cable FC having four cores, the first core 110, the second core 120, the third core 130, and the fourth core 140 are arranged in this order. In this case, the first core 110 and the third core 130 are the first ink detection unit 100. The second core 120 and the fourth core 140 are the second ink detection unit 200. Furthermore, a crack is formed between the cores. Each core can be bent and arranged so that the extension direction of the first core 110 and the third core 130 is opposite to the extension direction of the second core 120 and the fourth core 140.

[0059] (B11) In the above embodiment, an example was described in which the electrode terminals 111 and 121 were provided near one end of the multi-core flat cable FC, and the electrode terminals 131 and 141 were provided in a middle region of the multi-core flat cable FC (see FIG. 4). However, the electrode terminals 111 and 121 and the electrode terminals 131 and 141 may be provided near ends on the same side of the multi-core flat cable FC. Alternatively, the electrode terminals 111 and 121 may be provided near one end of the multi-core flat cable FC, and the electrode terminals 131 and 141 may be provided near the other end of the multi-core flat cable FC. Alternatively, the electrode terminals 111 and 121 and the electrode terminals 131 and 141 may be provided in a middle region of the multi-core flat cable FC.

[0060] (B12) In the above embodiment, an example in which two ink detection units are provided has been described, but the liquid leakage detection device 70 may also be provided with only one ink detection unit.

[0061] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0062] C. Other forms: (1) According to one aspect of the present disclosure, there is provided a liquid leakage detection device installed inside an inkjet recording device, the liquid leakage detection device including: an ink detection unit configured with an exposed conductor portion of a first core included in a multi-core flat cable and an exposed conductor portion of a second core included in the multi-core flat cable as a pair of electrode terminals; and a detection circuit that detects liquid leakage by detecting that the potential difference between the pair of electrode terminals falls below a predefined threshold. According to the above embodiment, by using the exposed portion of the core included in the multi-core flat cable as the ink detection section, the space occupied by the ink detection section within the inkjet recording device can be reduced, and the space efficiency within the inkjet recording device can be improved. (2) The liquid leakage detection device of the above aspect further includes a second ink detection unit configured with an exposed conductor portion of a third core included in the multi-core flat cable and an exposed conductor portion of a fourth core included in the multi-core flat cable as another pair of electrode terminals. The detection circuit detects that liquid has leaked by detecting that the potential difference between the pair of electrode terminals or the other pair of electrode terminals falls below a predefined threshold. The second ink detection unit may be located at a position different from that of the ink detection unit. According to the above aspect, a plurality of ink detection units can be configured using a multi-core flat cable. (3) In the liquid leak detection device of the above aspect, the first core and the second core are arranged adjacent to each other in the multi-core flat cable, and the third core and the fourth core are arranged adjacent to each other in the multi-core flat cable. The second core is adjacent to the third core on the side opposite to the first core. The pair of electrode terminals is composed of an exposed conductor portion of the first core on one surface of the multi-core flat cable and an exposed conductor portion of the second core on the same surface. The other pair of electrode terminals is composed of an exposed portion of the third core on the same surface and an exposed portion of the fourth core on the same surface. At least the first core and the second core are arranged in a bent state with a split formed from the end of the multi-core flat cable along the core-to-core gap between the second core and the third core, so that the first core and the second core extend in a direction different from the direction in which the third core and the fourth core extend. The pair of electrode terminals and the other pair of electrode terminals are arranged along the same plane inside the ink jet recording apparatus. (4) In the liquid leakage detection device of the above aspect, the first core and the second core are arranged adjacent to each other in the multi-core flat cable, and the third core and the fourth core are arranged adjacent to each other in the multi-core flat cable. The second core is adjacent to the third core on the opposite side to the first core. The pair of electrode terminals may be provided near one end of the multi-core flat cable, and the other pair of electrode terminals may be provided in a middle region of the multi-core flat cable. According to the above embodiment, the ink detection unit can be disposed at any desired position, not just at the end of the multi-core flat cable. (5) In the liquid leakage detection device of the above aspect, one of the pair of electrode terminals, a first electrode terminal constituted by an exposed portion of the first core, is electrically connected to the detection circuit. The other of the pair of electrode terminals, a second electrode terminal constituted by an exposed portion of the second core, is grounded. One of the other pair of electrode terminals, a third electrode terminal constituted by an exposed portion of the third core, is electrically connected to the detection circuit. The other of the other pair of electrode terminals, an electrode terminal constituted by an exposed portion of the fourth core, is grounded. The detection circuit may output a signal indicating that a liquid leakage has been detected when it detects a short circuit between the pair of electrode terminals or between the other pair of electrode terminals by detecting a voltage drop in the first core or the third core. (6) In the liquid leakage detection device of the above aspect, the detection circuit includes a first leakage signal terminal electrically connected to the first core, a first ground terminal electrically connected to the second core, a second leakage signal terminal electrically connected to the third core, a second ground terminal electrically connected to the fourth core, and a pull-up resistor one end of which is connected to a high potential side of a signal potential used by the detection circuit. The first ground terminal and the second ground terminal may be grounded, and the first leakage signal terminal and the second leakage signal terminal may be connected to the other end of the pull-up resistor. (7) In the liquid leakage detection device of the above aspect, the detection circuit may include at least one comparator for detecting a voltage drop in the first core or the third core. (8) In the liquid leakage detection device of the above aspect, the detection circuit may include at least one A / D converter for detecting a voltage drop in the first core or the third core. (9) According to another aspect of the present disclosure, there is provided an inkjet recording device including a liquid circulation unit, an ejection unit, a case storage unit, a control unit, and a liquid leakage detection device. The liquid leakage detection device includes an ink detection unit configured using an exposed conductor portion of a first core included in a multi-core flat cable and an exposed conductor portion of a second core included in the multi-core flat cable as a pair of electrode terminals, and a detection circuit that detects liquid leakage by detecting that the potential difference between the pair of electrode terminals falls below a predetermined threshold. According to the above embodiment, by using the exposed portion of the core included in the multi-core flat cable as the ink detection section, the space occupied by the ink detection section within the inkjet recording device can be reduced, and the space efficiency within the inkjet recording device can be improved.

[0063] The present disclosure is not limited to the form of the inkjet recording apparatus described above, but can be realized in various forms such as an inkjet system, a multifunction peripheral equipped with an inkjet recording apparatus, and the like. [Explanation of symbols]

[0064] IC1 to IC4...ink cartridge IC, 10...printing device, 10h...housing, 12...front portion, 13...operation panel, 14...media discharge port, 15...paper discharge tray, 16...paper feed tray, 17...mounting port, 18...cover member, 19...case storage section, 20...liquid circulation section, 21...tube, 22...circulation pipe, 25...pump, 30...ejection execution section, 31...print head, 34...carriage, 35...media transport section, 36...transport roller, 40...control section, 70...liquid leak detection device, 100...first ink detection section, 110...first core, 111...electrode terminal, 120...second core, 121...electrode terminal, 130...third core, 131...electrode terminal, 140...fourth core A, 141...electrode terminal, 150...fifth core, 151...electrode terminal, 160...sixth core, 161...electrode terminal, 200...second ink detection unit, 211...electrode terminal, 300...detection circuit, 300B...control board, 301...first leakage signal terminal, 302...first ground terminal, 303...second leakage signal terminal, 304...second ground terminal, 305...pull-up resistor, 306...comparator, 400...third ink detection unit, C1...capacitor, EL1 to EL6...electrodes, FC2...multi-core flat cable, It...short circuit current, M...medium, N...nozzle, R1...resistor, S1...case, Vdd1...power supply, Vink_leak...output, Vref1...reference potential.

Claims

1. A liquid leakage detection device provided inside an ink jet recording device, an ink detection unit configured as a pair of electrode terminals, the electrode terminals being an exposed conductor portion of a first core included in a multi-core flat cable and an exposed conductor portion of a second core included in the multi-core flat cable; a detection circuit that detects that a liquid has leaked by detecting that a potential difference between the pair of electrode terminals has fallen below a predefined threshold; A liquid leakage detection device comprising:

2. 2. The liquid leakage detection device according to claim 1, a second ink detection unit configured with an exposed conductor portion of a third core included in the multi-core flat cable and an exposed conductor portion of a fourth core included in the multi-core flat cable as another pair of electrode terminals; Furthermore, the detection circuit detects that a liquid has leaked by detecting that a potential difference between the pair of electrode terminals or the other pair of electrode terminals has fallen below a predefined threshold; the second ink detection unit is disposed at a position different from the position at which the ink detection unit is disposed; Liquid leak detection device.

3. 3. The liquid leakage detection device according to claim 2, the first core and the second core are arranged adjacent to each other in the multi-core flat cable, and the third core and the fourth core are arranged adjacent to each other in the multi-core flat cable, the second core is adjacent to the third core on the side opposite to the first core, the pair of electrode terminals are composed of an exposed conductor portion of the first core O1 on one surface of the multi-core flat cable and an exposed conductor portion of the second core O1 on the one surface, the other pair of electrode terminals is composed of an exposed portion of the third core on the one surface and an exposed portion of the fourth core on the one surface, a split is formed from an end of the multi-core flat cable along a core-to-core distance between the second core and the third core, and at least the first core and the second core are arranged in a bent state, so that the first core and the second core extend in a direction different from a direction in which the third core and the fourth core extend; the pair of electrode terminals and the other pair of electrode terminals are arranged along the same plane inside the ink jet recording device, Liquid leak detection device.

4. 3. The liquid leakage detection device according to claim 2, the first core and the second core are arranged adjacent to each other in the multi-core flat cable, and the third core and the fourth core are arranged adjacent to each other in the multi-core flat cable, the second core is adjacent to the third core on the side opposite to the first core, the pair of electrode terminals are provided near one end of the multi-core flat cable, the other pair of electrode terminals is provided in a middle region of the multi-core flat cable; Liquid leak detection device.

5. 5. The liquid leakage detection device according to claim 3 or 4, a first electrode terminal, which is one of the pair of electrode terminals and is constituted by an exposed portion of the first core, is electrically connected to the detection circuit; the other of the pair of electrode terminals, a second electrode terminal formed by an exposed portion of the second core, is grounded; a third electrode terminal, which is one of the other pair of electrode terminals and is configured by an exposed portion of the third core, is electrically connected to the detection circuit; the other of the other pair of electrode terminals, which is formed by an exposed portion of the fourth core, is grounded, The detection circuit a signal indicating that a liquid leakage has been detected when a short circuit between the pair of electrode terminals or a short circuit between the other pair of electrode terminals is detected by detecting a voltage drop in the first core or the third core; Liquid leak detection device.

6. 6. The liquid leakage detection device according to claim 5, The detection circuit a first leakage signal terminal electrically connected to the first core; a first ground terminal electrically connected to the second core; a second leakage signal terminal electrically connected to the third core; a second ground terminal electrically connected to the fourth core; a pull-up resistor connected to a high potential side of a signal potential used by the detection circuit; Equipped with the first ground terminal and the second ground terminal are grounded; the first leakage signal terminal and the second leakage signal terminal are connected to the other of the pull-up resistors; Liquid leak detection device.

7. 7. The liquid leakage detection device according to claim 6, the detection circuit comprises at least one comparator for detecting a voltage drop in the first core or the third core; Liquid leak detection device.

8. 7. The liquid leakage detection device according to claim 6, the detection circuit comprises at least one A / D converter for detecting a voltage drop in the first core or the third core; Liquid leak detection device.

9. An ink jet recording apparatus, The liquid leakage detection device includes a liquid circulation unit, a spray execution unit, a case storage unit, a control unit, and a liquid leakage detection device. The liquid leakage detection device includes: an ink detection unit configured by using an exposed conductor portion of a first core included in a multi-core flat cable and an exposed conductor portion of a second core included in the multi-core flat cable as a pair of electrode terminals; a detection circuit that detects that a liquid has leaked by detecting that a potential difference between the pair of electrode terminals has fallen below a predefined threshold; Equipped with Inkjet recording device.

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