JP6492457B2 - Liquid detection device and liquid application device - Google Patents

Description

  The present invention relates to a liquid detection device and a liquid application device.

  In recent years, there has been a tendency to digitize information, and image processing apparatuses such as printers and facsimiles used for outputting digitized information and scanners used for digitizing documents have become indispensable devices. Such an image processing apparatus is often configured as a multifunction machine that can be used as a printer, a facsimile, a scanner, or a copier by providing an imaging function, an image forming function, a communication function, and the like.

  Among such image processing apparatuses, image forming apparatuses used for outputting digitized documents improve printing quality by avoiding conditions that affect printing quality such as bleeding, density fluctuation, color tone fluctuation, and show-through. Therefore, a technique of applying a treatment liquid for aggregating the color material of the ink by pretreatment is generally known.

  Since such a processing liquid is put in a container and the processing liquid is supplied from the container and consumed during the above-described pretreatment, it is necessary to replenish the container with the processing liquid as needed. As one aspect thereof, a method is known in which a voltage is applied between electrode pins of a conductor and the remaining amount of liquid is detected by a resistance value.

  In the detection using such an electrode, for the purpose of accurately detecting the remaining amount of ink, the ink resistance value for each environmental temperature is stored, and the detection voltage applied to the ink is less than the electrolysis voltage. Setting has been proposed (see, for example, Patent Document 1).

  The sensor using the electrode as described above is a contact type, and when the electrode placed in the direction perpendicular to the liquid level of the processing liquid placed in the container and the processing liquid are in contact, It is detected that the remaining amount is not less than a predetermined amount. In addition, when the processing liquid is consumed and the liquid level is lowered, and the electrode and the liquid level are not in contact with each other, it is detected that the remaining amount of the processing liquid is less than a predetermined amount.

  However, when the processing liquid contained in the container is consumed and the height of the liquid level decreases, the liquid remains on the wall surface depending on the condition of the liquid on the wall surface inside the container, and the liquid film is formed on the wall surface inside the container. May be stretched. When a liquid film is stretched on the inner wall of the container holding the electrode used for the sensor as described above, the resistance value changes depending on the state of the liquid film, and the electrode and the liquid surface of the processing liquid contact each other. In spite of this, it may be detected that the electrode and the processing liquid are in contact with each other, and the remaining amount of the processing liquid may be erroneously detected.

  In the technique disclosed in Patent Document 1, the influence of the liquid film stretched inside the container containing the processing liquid is not considered. Such a problem is not limited to the container containing the processing liquid in the image forming apparatus, and may occur in the same manner as long as the container contains the liquid in the liquid application apparatus that supplies and applies the liquid.

  The present invention has been made to solve such a problem, and an object thereof is to reduce erroneous detection of a sensor that detects the remaining amount of liquid contained in a container.

In order to solve the above problems, one aspect of the present invention is a liquid detection device that detects the remaining amount of liquid stored in a liquid storage container, and is connected to the liquid storage container. A case in which liquid is introduced, the liquid level of the liquid introduced from the liquid container inside the case moves according to the remaining amount of liquid in the liquid container , and the inner wall of the case a plurality of conductors for detecting the presence or absence of contact with the liquid in the interior of the case is provided to protrude from the front Symbol wall vertically downward, said plurality of conductors arranged along a direction in which the liquid surface moves The direction in which the plurality of conductors are arranged is inclined by 5 ° or more with respect to the liquid surface and the horizontal direction, and the plurality of conductors are provided so that the interval between adjacent conductors is 20 mm or more. ing.

  ADVANTAGE OF THE INVENTION According to this invention, the misdetection of the sensor which detects the residual amount of the liquid accommodated in the container can be reduced.

1 is a diagram illustrating an overall configuration of an image forming system including a pretreatment liquid coating apparatus according to an embodiment of the present invention. It is a figure which shows the structure of the pre-processing liquid coating device which concerns on embodiment of this invention. It is a figure which illustrates the structure of the general liquid level detection sensor for a comparison with the liquid level detection sensor which concerns on embodiment of this invention. It is a graph which illustrates the change of the output according to the residual amount of the process liquid of the general liquid level detection sensor for comparison with the liquid level detection sensor which concerns on embodiment of this invention. It is a figure which illustrates the composition of the liquid level detection sensor concerning the embodiment of the present invention. It is a graph which illustrates the relationship between the angle of the top | upper surface and detection time lag in the liquid level detection sensor which concerns on embodiment of this invention, and the relationship between an electrode pin space | interval and a detection time lag. It is a figure which illustrates the change of the output according to the residual amount of the process liquid of the liquid level detection sensor shown in FIG. 5 which concerns on embodiment of this invention. It is a figure which illustrates the composition of the liquid level detection sensor concerning the embodiment of the present invention. It is a figure which illustrates the change of the output according to the residual amount of the processing liquid of the liquid level detection sensor shown in Drawing 8 concerning the embodiment of the present invention. It is a figure which illustrates the composition of the liquid level detection sensor concerning the embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, an image forming system including an ink jet type image forming apparatus using roll paper will be described with a liquid application device that applies a liquid on a paper surface before image formation output by the image forming apparatus.

  FIG. 1 is a diagram illustrating a configuration of the entire image forming system according to the present embodiment. As shown in FIG. 1, the image forming system according to the present embodiment applies a liquid to the surface of the roll paper S sent out from the preprocessing machine 1 and the preprocessing machine 1 that feeds the roll paper S wound in a roll shape. The pretreatment liquid coating device 2, the inkjet printer main body 3 that forms an image by discharging the color material onto the roll paper coated with the liquid by the pretreatment liquid coating device 2, and the paper on which the image is formed is wound up A processor 4 is included. That is, in the present embodiment, the pretreatment liquid coating apparatus 2 functions as a liquid coating apparatus.

  In the configuration shown in FIG. 1, the gist of the present embodiment is that the pretreatment liquid application device 2 detects the remaining amount of liquid in a liquid storage container in which the liquid applied to the roll paper surface is stored. It is in the configuration. In the pretreatment liquid coating apparatus 2, a treatment liquid that is a modifier for modifying the surface of the roll paper S is applied to the roll paper. When the treatment liquid is applied to the entire surface of the roll paper S, the moisture of the ink discharged onto the surface of the roll paper S in the inkjet printer main body 3 quickly permeates the roll paper S and the color component increases in viscosity. In the present embodiment, a roll paper is described as an example to which the treatment liquid is applied by the pretreatment liquid application apparatus 2, but the material is not limited to paper, and a film, a plastic sheet, or the like may be used.

  Next, the configuration of the pretreatment liquid coating apparatus 2 according to this embodiment will be described with reference to FIG. As shown in FIG. 2, the pretreatment liquid coating apparatus 2 according to the present embodiment performs processing on the coating unit 200 and the coating unit 200 that apply the processing liquid to the roll paper 205 that is the object in the transport path of the roll paper 205. It includes a reserve tank 224 and cartridges 229 and 238 which are supply units for supplying liquid.

  Further, the application unit 200 includes a cylindrical application roller 201 that applies the processing liquid, a squeeze roller 202 that thins the processing liquid and transfers it to the application roller 201, and a pressure roller that sandwiches the roll paper 205 between the application roller 201. 203. The squeeze roller 202 is immersed in the processing liquid in the supply pan 204 that stores the processing liquid, and the liquid level detection sensor 206 that detects the amount of liquid in the supply pan 204 controls the liquid level height. The coating amount is made constant.

  Specifically, the liquid level detection sensor 206 includes a plurality of electrode pins 207a to 207d, and detects the remaining amount of the processing liquid in the supply pan 204 based on a current that flows when a voltage is applied between the electrode pins. . That is, the liquid level detection sensor 206 functions as a liquid detection device that detects the remaining amount of liquid stored in the liquid storage container.

  The configuration for reducing such erroneous detection of the remaining amount of the processing liquid by the liquid level detection sensor 206 is the gist according to the present embodiment. Details will be described later. In the liquid level detection sensor illustrated in FIG. 2, the case where the liquid level detection sensor includes four electrode pins 207 a to 207 d is described as an example, but the number of electrode pins is not limited thereto. In addition, hereinafter, the electrode pins 207a to 207b may be referred to as the electrode pins 207 without being distinguished.

  The supply pan 204 is formed so as to cover the application roller 201, and suppresses evaporation of the processing liquid in the supply pan 204. However, the pressure contact portion between the application roller 201 and the pressure roller 203 needs to be opened, and is not a complete sealed system.

  Therefore, a substantially sealed reserve tank 224 is provided in the supply unit. When the solenoid valve 226 provided in the retreat path 225 that communicates the reserve tank 224 and the supply pan 204 is opened, the processing liquid in the supply pan 204 is transferred to the reserve tank 224 through the retreat path 225 due to a water head difference. The With such a configuration, an increase in the viscosity of the treatment liquid can be suppressed.

  Note that when the electromagnetic valve 226 is opened, for example, the printing process is stopped for a time (for example, 1 hour or more) longer than the work time between normal print jobs such as replacement of the roll paper 205 and change of the print pattern. In this case, the waiting time for filling the supply liquid into the supply pan 204 does not occur every time printing is stopped.

  Further, since the electromagnetic valve 226 is opened when power is not supplied, the processing liquid stored in the supply pan 204 is transferred to the reserve tank 224 when the power of the pretreatment liquid coating apparatus 2 is shut off. The With such a configuration, the processing liquid is prevented from remaining in the supply pan 204 for a long time.

  Also, in the reserve tank 224, when the processing liquid has not been used for a long time (for example, several tens of days or more), the viscosity of the processing liquid increases. Therefore, when the processing liquid has not been used in the reserve tank 224 for a certain period of time, the processing liquid in the reserve tank 224 is discharged into the waste liquid tank 221 by the waste liquid pump 222, so that the freshness of the processing liquid is maintained.

  Further, a circulation path 228 communicating from the retreat path 225 to the filter 227 is branched. In this circulation path 228, an electromagnetic valve 232 is provided on the upstream side of the filter 227, and a three-way valve 233 is provided on the downstream side. The filter 227 removes paper dust and the like remaining in the supply pan 204 and prevents the processing liquid from becoming pasty. Note that paper dust or the like staying in the supply pan 204 is generated when the roll paper 205 is slid and moved by the application roller 201 and the pressure roller 203 (sliding).

  When the electromagnetic valve 232 is appropriately opened while applying the processing liquid, a part of the processing liquid in the supply pan 204 is passed through the retreat path 225 and the circulation path 228 to the filter 227. Paper dust contained in the treatment liquid is removed. When the three-way valve 233 is brought into communication with the filter 227 and the supply pan 204 and the supply pump 230 is driven, the processing liquid from which the paper dust has been removed by the filter 227 is supplied to the supply pan 204 by the supply pump 230. The

  The supply of the processing liquid to the supply pan 204 is performed from the reserve tank 224 or the cartridges 229 and 238 which are supply units. The reserve tank 224 is provided with a sensor 210 that detects the remaining amount of the processing liquid in the reserve tank 224.

  When the sensor 210 detects that the remaining amount of the processing liquid in the reserve tank 224 is greater than or equal to a predetermined amount, the electromagnetic valve 236 is opened. When the electromagnetic valve 236 is opened, the processing liquid stored in the reserve tank 224 is passed through the filter 227 from the circulation supply path 235 that communicates the reserve tank 224 with the filter 227. When the three-way valve 233 is brought into a state where the filter 227 and the supply pan 204 communicate with each other and the supply pump 230 is driven, the processing liquid passed through the filter 227 is supplied to the supply pan 204 by the supply pump 230.

  On the other hand, when the sensor 210 detects that the remaining amount of the processing liquid in the reserve tank 224 is less than a predetermined amount, the supply is performed from one of the cartridges 229 and 238. For example, when the supply from the cartridge 229 is performed, the electromagnetic valve 234 is opened, the three-way valve 233 is brought into communication with the supply pan 204, and the supply pump 230 is driven. Then, the processing liquid contained in the cartridge 229 is supplied to the supply pan 204 by the supply pump 230 through the path 231.

  Further, an EMPTY sensor 223 that detects the presence or absence of the processing liquid in the cartridges 229 and 238 is provided on the path 231. For example, when it is detected that there is no processing liquid in the cartridge 229, the control is switched to supply from the cartridge 238. As a result, the electromagnetic valve 237 is opened, and the processing liquid contained in the cartridge 238 is supplied to the supply pan 204 by the supply pump 230 through the path 231.

  Meanwhile, the cartridge 229 detected as having no processing liquid is replaced with a new cartridge. As described above, the configuration in which a plurality of cartridges can be mounted makes it possible to replace the cartridges without stopping the operation of the pretreatment liquid coating apparatus 2. In the present embodiment, the case where two cartridges 229 and 238 are mounted has been described as an example. However, this is an example, and three or more cartridges may be mounted.

  Next, the structure of a general liquid level detection sensor will be described. FIG. 3 is a diagram illustrating a configuration of a general liquid level detection sensor for comparison with the liquid level detection sensor 206 according to the present embodiment. FIG. 3 is a cross-sectional view showing a part of the liquid level detection sensor. The liquid level detection sensor shown in FIG. 3 is composed of two electrode pins 207a and 207b held in the case. To do. Further, as shown in FIG. 3, the electrode pin 207 is provided to protrude vertically downward from the inner wall of the liquid level detection sensor.

  An alternating current is applied to one electrode pin (here, referred to as electrode pin 207a), and the other electrode pin (here, referred to as electrode pin 207b) is GND. As shown in FIG. 3A, when the electrode pins 207a and 207b are immersed in the processing liquid in the liquid level detection sensor (indicated by dots in FIG. 3), charge is transferred by ions in the liquid. Therefore, the liquid level detection sensor can obtain an output corresponding to the flowed electric charge.

  FIG. 4 is a graph illustrating an output change according to the remaining amount of the processing liquid in the liquid level detection sensor having the configuration shown in FIG. As shown in FIG. 4, the horizontal axis represents the elapsed time (seconds), and the vertical axis represents the output value of the liquid level detection sensor (hereinafter referred to as “sensor output value”) (V).

  It is assumed that the processing liquid decreases as time elapses from the state in which the processing liquid is sufficiently contained in the liquid level detection sensor. When the processing liquid is sufficiently contained in the liquid level detection sensor and the electrode pins 207a and 207b are completely immersed in the processing liquid (for example, between the elapsed time 0 seconds and 25 seconds shown in FIG. 4), the sensor The output value is approximately 0V.

  As the processing liquid in the supply pan 204 decreases, the height of the liquid level in the liquid level detection sensor decreases, so as shown in FIG. 3B, the electrode pins 207a and 207b and the liquid of the processing liquid It will be separated from the surface soon. In this case, since there is no contact between the electrode pins 207a and 207b and the processing liquid, the remaining amount of the processing liquid in the supply pan 204 from the sensor output value is 0 V at the timing when the electrode pins 207a and 207b are separated from the liquid surface. Changes to a value (for example, 2 V) larger than a threshold value (slice level) for detecting that there is a shortage.

  That is, the electrode pins 207a and 207b are conductors that detect the presence or absence of contact with the liquid whose liquid level moves inside the liquid detection device in accordance with the remaining amount of liquid stored in the supply pan 204, which is a liquid storage container. is there. The liquid level detection sensor detects the remaining amount of liquid in the supply pan 204 based on detection of the presence or absence of contact with the liquid by such a conductor.

  However, when the configuration of the liquid level detection sensor is the configuration shown in FIG. 3, the liquid remains on the top surface of the liquid level detection sensor that holds the electrode pins 207a and 207b, as shown in FIG. A liquid film stretches on the surface.

  Since the resistance value changes due to the influence of the liquid film, even if the electrode pins 207a, 207b and the liquid surface are separated from each other, the rise of the sensor output value becomes dull. In FIG. 6, a lag (for example, about 15 seconds in the graph shown in FIG. 4) occurs at a timing until it exceeds the 1 V line indicated by a dotted line. Therefore, although the electrode pins 207a and 207b are separated from the liquid level, the liquid level detection sensor erroneously detects that the remaining amount of the processing liquid in the supply pan 204 is greater than or equal to a predetermined amount.

  The configuration of the liquid level detection sensor 206 for reducing such erroneous detection is the gist according to the present embodiment. Hereinafter, the configuration of the liquid level detection sensor 206 according to the present embodiment will be described.

  FIG. 5 is a diagram illustrating the configuration of the liquid level detection sensor 206 according to this embodiment. FIG. 5 is a cross-sectional view showing a part of the liquid level detection sensor 206, and the liquid level detection sensor 206 shown in FIG. 5 is composed of two electrode pins 207a and 207b. As shown in FIG. 5, the top surface that holds the electrode pins 207a and 207b of the liquid level detection sensor 206 is inclined in the horizontal direction with respect to the liquid level of the processing liquid.

  With such a configuration, when the liquid level of the processing liquid in the liquid level detection sensor 206 is lowered, the liquid remaining on the top surface is, as shown in FIG. It flows to the side and is discharged. That is, in the configuration of the liquid level detection sensor 206 shown in FIG. 5, when the electrode pins 207a and 207b are separated from the liquid level, the liquid remaining on the top surface is less than in the configuration shown in FIG. .

  Further, as shown in FIG. 5, the interval between the adjacent conductors of the liquid level detection sensor 206, that is, the interval between the electrode pin 207a and the electrode pin 207b (hereinafter referred to as “electrode pin interval”) is shown in FIG. It is wider than the electrode pin interval of the liquid level detection sensor. Since a small amount of liquid remains around the electrode pins 207 due to the surface tension of the liquid, when the distance between the electrode pins is narrow, a liquid film is stretched between the electrode pins.

  Due to the influence of such a liquid film, as described above, the liquid level detection sensor having a narrow electrode pin interval, although the electrode pins 207a and 207b are separated from each other, has a residual liquid in the supply pan 204. If the amount is greater than or equal to a predetermined amount, it will be erroneously detected. With the configuration shown in FIG. 5, the distance between the electrode pins is wide, and the liquid film is less likely to be stretched between the electrode pins than in the configuration shown in FIG. 3.

  A specific top surface inclination angle and electrode pin interval in the configuration of the liquid level detection sensor 206 shown in FIG. 5 will be described. FIG. 6A is a graph showing the relationship between the angle of the top surface and the detection time lag in the configuration of the liquid level detection sensor 206 shown in FIG. FIG. 6B is a graph showing the relationship between the electrode pin interval and the detection time lag in the configuration of the liquid level detection sensor 206 shown in FIG.

  The vertical axis of the graphs shown in FIGS. 6A and 6B indicates the detection time lag. The detection time lag indicates the time from when the electrode pin 207 is separated from the liquid surface until it is detected that the remaining amount of the processing liquid is insufficient (less than a predetermined amount). That is, when the detection time lag is larger than the predetermined size, the liquid level detection sensor 206 erroneously detects that the remaining amount of the processing liquid is equal to or more than a predetermined amount even though the remaining amount of the processing liquid is insufficient. doing.

  Further, the horizontal axis of the graph shown in FIG. 6A indicates the inclination angle of the top surface of the liquid level detection sensor 206, and the horizontal axis of the graph shown in FIG. 6B indicates the electrode pin in the liquid level detection sensor 206. The interval (mm) is shown.

  As shown to Fig.6 (a), when the inclination | tilt angle of a top | upper surface is 5 degrees or more, the detection time lag has shown the value close | similar to 0. In addition, as shown in FIG. 6B, when the electrode pin interval is 20 mm or more, the detection time lag shows a value close to zero. Therefore, in the liquid level detection sensor 206 shown in FIG. 5, when the inclination angle of the top surface is 5 ° or more and the electrode pin interval is 20 mm or more, the detection time lag becomes close to zero. That is, when the inclination angle of the top surface is 5 ° or more and the electrode pin interval is 20 mm or more, the treatment liquid does not remain on the top surface and the liquid film does not stretch between the electrode pins.

  FIG. 7 is a graph illustrating an output change according to the remaining amount of the processing liquid of the liquid level detection sensor 206 in which the top surface has an inclination angle of 5 ° and the electrode pin interval is 20 mm. The vertical axis and horizontal axis of the graph shown in FIG. 7 are the same as the vertical axis and horizontal axis of the graph shown in FIG. As described above, in the liquid level detection sensor 206 in which the inclination angle of the top surface is 5 ° or more and the electrode pin interval is 20 mm or more, no treatment liquid remains on the electrodes, and a liquid film is stretched between the electrode pins. Nor. Therefore, when the electrode pin 207 and the liquid surface are separated from each other, the output value is not affected by the liquid film, and the electrode pins 207a and 207b are completely insulated.

  Therefore, as shown in FIG. 7, at the timing when the electrode pin 207 and the liquid level are separated from each other, the sensor output value immediately rises from 0V to 2V, and the liquid level detection sensor 206 detects the remaining amount of the processing liquid in the supply pan 204. Correctly detect that is missing.

  As described above, the liquid level detection sensor 206 of the pretreatment liquid coating apparatus 2 according to the present embodiment is configured such that the inclination angle of the top surface is 5 ° or more and the electrode pin interval is 20 mm or more. With such a configuration, the sensor output value when the electrode pin 207 and the liquid level of the processing liquid are separated from each other by reducing the processing liquid in the supply pan 204 and decreasing the liquid level holds the sensor 210. Since the influence of the liquid film stretched on the top surface can be made less affected than before, it is possible to reduce erroneous detection of the sensor that detects the remaining amount of the liquid stored in the liquid storage container.

  The present embodiment is not limited to the supply pan 204 that is a container containing processing liquid in the image forming apparatus, but can be similarly applied to a container that contains liquid in a liquid application apparatus that supplies and applies liquid. It is. Note that the liquid detection device according to the present embodiment has been described as an example in which the liquid detection device 206 detects the remaining amount of liquid stored in the supply pan 204. In addition, this embodiment is similarly applicable even when the reserve tank 224 having the sensor 210 is a liquid detection device.

  In the liquid level detection sensor 206 according to this embodiment, the inner side of the top surface may have water repellency. Specifically, for example, a water repellent coat may be applied to the inside of the top surface, or the top surface itself may be formed of a water repellent material such as a fluorine material. FIG. 8 is a diagram illustrating the configuration of the liquid level detection sensor 206 in which the inside of the top surface has water repellency. FIG. 8 is a cross-sectional view showing a part of the liquid level detection sensor 206, and the liquid level detection sensor 206 shown in FIG. 8 is composed of two electrode pins 207a and 207b.

  As shown in FIG. 8B, since the inside of the top surface of the liquid level detection sensor 206 has water repellency, the liquid remaining on the top surface becomes spherical due to surface tension, and the liquid is separated from the top surface and the electrode pins 207. This makes it easier for the liquid to remain on the top surface than in the configuration shown in FIG.

  FIG. 9 is a diagram illustrating a change in output corresponding to the remaining amount of the processing liquid of the liquid level detection sensor 206 shown in FIG. The vertical axis and horizontal axis of the graph shown in FIG. 9 are the same as the vertical axis and horizontal axis of the graph shown in FIG. As described above, since the inside of the top surface of the liquid level detection sensor 206 has water repellency, the liquid is less likely to remain on the top surface. Therefore, as shown in FIG. 9, at the timing when the electrode pin 207 and the liquid surface are separated from each other, the sensor output value rises from 0V to 2V earlier than the case shown in FIG. With such a configuration, the liquid level detection sensor 206 can more correctly detect that the remaining amount of the processing liquid in the supply pan 204 is insufficient.

  FIG. 10 is a diagram illustrating the configuration of the liquid level detection sensor 206 according to this embodiment. As shown in FIG. 10A, the liquid level detection sensor 206 includes an insulator case 251 and a plurality of electrode pins 207 held by the case 251. In addition, the plurality of electrode pins 207 (conductors) are arranged along the direction in which the liquid level moves. Further, the liquid level detection sensor 206 is connected to the supply pan 204 via the tube 252 and the nipple 253.

  As shown in FIG. 10A, in the liquid level detection sensor 206, the direction in which the plurality of electrode pins 207 are arranged is inclined by 5 ° or more with respect to the liquid level of the processing liquid 254. The processing liquid does not stay on the inner wall of the liquid level detection sensor 206 to be held. The case 251 has a pipe shape and is formed of a material such as polypropylene, polyethylene, or polycarbonate. A water repellent coat may be applied to the inside of the case 251 formed of the above-described material. The case 251 itself may be formed of a water-repellent material such as polytetrafluoroethylene (tetrafluoroethylene) or a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer.

  Further, as the inner diameter of the case 251 is thinner, it is affected by the surface tension of the processing liquid, so that the liquid level in the case 251 tends to be perpendicular to the inner diameter of the case and does not match the liquid level of the supply pan 204. 206 cannot correctly detect the remaining amount of liquid. Therefore, it is preferable to make the inner diameter of the case 251 as large as possible with a diameter of 10 mm or more.

  A voltage is applied to the one or more electrode pins 207 by alternating current, and the one or more electrode pins 207 are GND. The electrode pins 207 are attached to a substrate (not shown) via a connector (not shown). In a state where there is a liquid in the substrate, since charge is transferred by ions in the liquid, the liquid level detection sensor 206 outputs a sensor value corresponding to the flowed electric charge.

  As described above, since the liquid film is stretched between the electrode pins 207 when the electrode pin interval is narrow, as shown in FIG. 10A, the electrode pins 207 are arranged with an interval of 20 mm or more. FIG. 10B is a cross-sectional view of the liquid level detection sensor 206 cut along the plane A shown in FIG. As shown in FIG. 10B, the electrode pin 207 is preferably mounted near 45 ° with respect to the liquid surface of the processing liquid 254.

  When the electrode pins 207 are mounted perpendicularly to the liquid surface of the processing liquid 254, the liquid remaining on the upper surface of the case 251 is symmetrical and well-balanced, and the processing liquid 254 is not easily discharged. Further, when the electrode pin 207 is parallel to the liquid surface of the processing liquid 254, the area of the electrode pin 207 close to the liquid surface is large and the liquid breakage becomes worse. For this reason, the configuration as shown in FIG. 10B can prevent the treatment liquid 254 from staying on the top surface of the case 251.

DESCRIPTION OF SYMBOLS 1 Pre-processing machine 2 Pre-processing liquid coating apparatus 3 Inkjet printer main body 4 Post-processing machine 200 Application | coating part 201 Application roller 202 Squeeze roller 203 Pressure roller 204 Supply pan 205 Roll paper 206 Liquid level detection sensor 207 Electrode pin 210 Sensor 221 Waste liquid tank 222 Waste liquid pump 223 EMPTY sensor 224 Reserve tank 225 Retreat path 226, 232, 234, 236, 237 Solenoid valve 227 Filter 228 Circulation path 229, 238 Cartridge 230 Supply pump 231 path 233 Three-way valve 235 Circulation supply path

Japanese Patent Laid-Open No. 06-270410

Claims (9)

A liquid detection device that detects the remaining amount of liquid stored in a liquid storage container,
A case connected to the liquid container and having a liquid introduced from the liquid container;
The liquid level of the liquid introduced from the liquid container inside the case moves according to the remaining amount of liquid in the liquid container ,
The inner wall of the casing, a plurality of conductors for detecting the presence or absence of contact with the liquid in the interior of the case is provided to protrude from the front Symbol wall vertically downward,
The plurality of conductors are arranged along a direction in which the liquid level moves,
The direction in which the plurality of conductors are arranged is inclined by 5 ° or more with respect to the liquid surface and the horizontal direction,
The plurality of conductors are provided such that an interval between adjacent conductors is 20 mm or more .
A liquid detection device characterized by that. The inner wall has water repellency ,
The liquid detection device according to claim 1. The inner wall is provided with a water-repellent coat ,
The liquid detection device according to claim 2. The inner wall is formed of a water repellent material ,
The liquid detection device according to claim 2. In a cross section orthogonal to the direction in which the liquid moves in the case, the plurality of conductors are provided to be inclined with respect to the liquid surface.
The liquid detection device according to claim 1, wherein the liquid detection device is a liquid detection device. The case is disposed to be inclined with respect to a horizontal plane;
The liquid detection apparatus according to claim 1, wherein the liquid detection apparatus is a liquid detection apparatus. The case includes an introduction port through which liquid is introduced from the liquid storage container and a discharge port through which liquid is discharged to the liquid storage container, and the introduction port and the discharge port are respectively connected to the liquid storage container.
The liquid detection device according to claim 1, wherein the liquid detection device is a liquid detection device. Liquid application apparatus, characterized in that it comprises a liquid detection device according to any one of claims 1 to 7. The liquid detection device detects a remaining amount of liquid in a liquid storage container in which a liquid to be applied to an object by the liquid application device is stored .
The liquid application apparatus according to claim 8 .