JP5352902B2 - Ink level monitoring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for monitoring the remaining amount of ink which prevents the liquid level from being erroneously detected when the liquid level of the ink is detected by floating a float on which a magnet is fitted on the ink liquid level of an ink chamber. <P>SOLUTION: The method for monitoring the remaining amount of the ink includes at least successively: the step 1 for detecting the height of the magnet; the step 2 for calculating the remaining amount of the ink based on the amount of consumption of the ink; the step 3 in which only when the height of the magnet is at the lowest standard height or lower and the remaining amount of the ink is smaller than a threshold value (for example, less than 50%), the ink is fed to an ink chamber; and the step 4 in which after feeding the ink is completed, and a specified time passes, the height of the magnet is detected. In the step 3, by the time when the magnet becomes a filling standard height, the amount of the ink to be forwarded is calculated, and by the maximum rotating time of the pump calculated from the calculating result, the pump is rotated to forward the ink. In the step 4, when the magnet is at the filling standard height, the remaining amount of the ink is made to be a fully filled condition (for example, 100%). <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for monitoring an ink remaining amount in a sub tank.

  Inkjet printers discharge ink particles from the nozzles and apply them to the print medium while moving the printer head with a large number of nozzles relative to the print medium. It is a device that draws the information. Ink jet printers consume ink as ink is ejected, so an ink tank (ink cartridge) with a capacity corresponding to the application is provided in the carriage of the printer head or the printer body. In a large inkjet printer that prints commercial large format advertisements and banners, a large amount of ink is consumed in a relatively short time. For this reason, in such a commercial inkjet printer, a large-capacity ink tank is generally provided in the printer body, and the ink tank and the printer head are connected by a tube or the like, and ink is ejected in accordance with ink ejection. The tank is configured to be supplied from the tank to the printer head.

  Here, when the internal pressure of the printer head becomes higher than the atmospheric pressure, the ink is pushed out from the nozzle and dropped onto the print medium, which causes a so-called “dropping” problem. Therefore, in the ink jet printer, the ink supply device is configured so that the internal pressure of the printer head is a slightly negative pressure slightly lower than the atmospheric pressure. As a conventional ink supply device, an ink supply (sub tank) having a small-capacity ink chamber is provided between an ink tank (main tank) provided in the printer body and a printer head provided in the carriage. 2. Description of the Related Art There is known a “negative pressure generation type” ink supply device that places a printer head in a slightly negative pressure state by depressurizing an ink chamber of a container (see, for example, Patent Document 1 and Patent Document 2).

  In the ink supply apparatus of the above method, control is performed so that a predetermined amount of ink is stored in the ink chamber of the ink supply according to the amount of ink discharged from the nozzle so that ink supply to the nozzle is not interrupted. Yes. As an example of this control, there is a method of detecting the ink level in the ink chamber and performing the detection based on the detected ink level. Specifically, control is performed to supply ink from the main tank to the ink chamber when it is detected that ink has been ejected from the nozzle and the liquid level of the ink has dropped to a predetermined lower limit height. At this time, as means for detecting the liquid level of the ink in the ink chamber, for example, in Patent Document 3, a float with a magnet attached is floated on the ink liquid surface so as to be movable up and down, and magnetism from the opposing magnet is detected. The structure which arrange | positions the sensor (Hall element) to perform in predetermined | prescribed height position (for example, minimum height) is disclosed. In the above configuration, the sensor can detect the magnetism from the magnet by facing the magnet, and the magnet can freely rotate and swing on the ink surface to improve the accuracy of magnetic detection. It is configured to move up and down in a restricted state.

JP 2004-284207 A JP 2006-62330 A JP 2001-141547 A

However, when the float with the magnet attached to the ink liquid level as described above is floated and moved up and down straight according to the change in the ink liquid level to detect the ink liquid level, the magnet will If it does not follow the liquid level for some reason, such as sticking to the ink, the liquid level of the ink may be erroneously detected.
For example, if the float sticks to the lower side, even if the ink is fully filled, the remaining amount of ink is regarded as insufficient (false detection), and the ink is replenished in the ink chamber. Then, the ink chamber has an ink supply port and an air path, but since the ink supply port and the air path are directly connected, the ink sent from the ink supply port to the ink chamber flows into the air path as it is. There was a risk of losing.

  The present invention has been devised in view of such a conventional situation. A float in which a magnet is attached to an ink liquid level in an ink chamber is floated and moved vertically up and down according to a change in the ink liquid level. An object of the present invention is to provide an ink remaining amount monitoring method capable of preventing erroneous detection of the liquid level even when the float does not follow the ink level for some reason when detecting the level of the ink. To do.

The ink remaining amount monitoring method according to claim 1 of the present invention is connected to a tank in which liquid ink is stored and a printer head that discharges liquid ink, respectively, and after temporarily storing the liquid ink flowing from the tank, the printer An ink chamber that flows out to the head, a liquid feed pump that feeds ink from the tank to the ink chamber, a float member that is movably moved in the ink chamber and floats in the liquid ink, and is attached to the float member An ink supply comprising at least a liquid level indicating member, wherein when the float member and the liquid level indicating member move up and down in the ink chamber, an ink residue for detecting a liquid level of ink in the ink chamber is detected. An amount monitoring method comprising: detecting a height of the liquid level indicating member in the ink chamber; Step 2 for calculating the remaining amount of ink in the ink chamber based on the consumption, Step 3 for feeding ink into the ink chamber according to the results of Step 1 and Step 2, and a predetermined time after completion of ink feeding After the elapse, the step 4 of detecting the height of the liquid level indicating member is provided at least in order, the height of the liquid level indicating member detected in the step 1 is less than or equal to a minimum reference height, and Only when the remaining amount of ink calculated in Step 2 is less than the threshold value, ink feeding is started in Step 3 until the height of the liquid level indicating member reaches the filling reference height in Step 3. The amount of liquid that can be fed is calculated, and the maximum rotation time of the liquid feeding pump is calculated from the calculation result. If Oite said calculated liquid level indication height filled reference height of the member, to determine the remaining ink level and fully filled condition (for example, 100%), characterized by.
According to a second aspect of the present invention, there is provided the ink remaining amount monitoring method according to the first aspect, wherein the height of the liquid level indicating member detected in the step 1 is equal to or lower than a minimum reference height, and the step 2 is performed. When the ink remaining amount calculated in step S is equal to or greater than the threshold value, or the height of the liquid level indicating member detected in step S1 is the reference filling height, and calculated in step S2. An error determination is made when the ink remaining amount is less than the threshold value.
According to a third aspect of the present invention, there is provided an ink remaining amount monitoring method according to the first aspect, wherein an error is determined when the height of the liquid level indicating member detected in the step 4 is equal to or lower than a minimum reference height. It is characterized by this.

  In the ink remaining amount monitoring method of the present invention, in the ink remaining amount control in the ink chamber (sub tank), in addition to detecting the height of the liquid level indicating member, the remaining ink amount calculated from the ink consumption is also monitored. Therefore, even if the liquid level indicating member does not follow the ink level for some reason, such as when the float in the ink chamber sticks to the inner wall of the tank, the liquid level height is detected incorrectly. Can be prevented. As a result, in the present invention, it is possible to prevent a situation in which the sent ink flows into the air path.

FIG. 3 is an external perspective view of the printer device from an oblique front. FIG. 2 is an external perspective view of the printer device from an oblique rear side. It is a front view which shows the principal part structure of the apparatus main body in the said printer apparatus. It is a systematic diagram of an ink supply apparatus. It is a perspective view of the carriage periphery in the printer apparatus. It is a general-view perspective view of the sub tank provided in the carriage. It is sectional drawing which showed the VII-VII part in FIG. It is sectional drawing which showed the VIII-VIII part in FIG. It is a schematic block diagram of an ink supply apparatus. 3 is a flowchart showing an outline of a method for monitoring the remaining amount of ink according to the present invention. It is a flowchart which shows the more detailed process of the ink residual amount monitoring method of this invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
First, a configuration example of an ink jet printer to which the ink remaining amount monitoring method of the present invention is applied will be described.
In this specification, as an example of an ink jet printer, out of two orthogonal axes along the surface to be printed, a type in which one axis moves the printing medium and the other axis moves the printer head is taken, and ultraviolet light irradiation is performed. A configuration example applied to a UV curable ink jet printer (hereinafter referred to as a printer device) using an ultraviolet curable ink (so-called UV ink) that is received and cured will be described.
FIG. 1 is a perspective view of the printer device P as viewed from the diagonally front, FIG. 2 is a perspective view of the printer device P as viewed from the diagonally rear, and FIG. First, the overall configuration of the printer apparatus P will be outlined with reference to these drawings. In the following description, directions indicated by arrows F, R, and U added in FIG. 1 will be referred to as front, right, and upward, respectively.

  The printer device P is broadly divided into a device main body 1 that performs a drawing function, and a feed mechanism 3 that feeds an unprinted print medium M that is provided in front of and behind a support portion 2 that supports the device main body 1 and wound in a roll shape. The winding mechanism 4 is configured to wind up the print medium M that has been drawn.

  The apparatus main body 1 is formed with a horizontally long window-shaped media insertion portion 15 through which the print medium M is inserted in the front and rear intermediate portions of the frame 10 forming the casing, and a lower frame 10L positioned below the media insertion portion 15. Are provided with a platen 20 that supports the print medium M, and a medium moving mechanism 30 that moves the print medium M supported by the platen 20 back and forth. The upper frame 10U positioned above the medium insertion portion 15 is provided with a printer head. A carriage 40 that holds 60 and a carriage moving mechanism 50 that moves the carriage 40 to the left and right are provided. The apparatus main body 1 includes a printer such as a front and rear movement of the print medium M by the medium moving mechanism 30, a right and left movement of the carriage 40 by the carriage moving mechanism 50, an ink discharge by the printer head 60, and an ink supply by the ink supply device 100 described later. A control unit 80 for controlling the operation of each part of the apparatus P is provided, and an operation panel 88 is disposed on the front surface of the apparatus body 1.

  The platen 20 is provided on the lower frame 10 </ b> L so as to extend back and forth below the media insertion portion 15, and a media support portion 21 for horizontally supporting the print medium M is provided in the left and right belt-like drawing areas by the printer head 60. Is formed. A large number of small-diameter suction holes are formed in the media support portion 21 and connected to a decompression chamber (not shown) provided therebelow, and the decompression chamber is set to a negative pressure by operating a vacuum generator or the like. Sometimes, the print medium M is sucked and held on the medium support portion 21 so that the position of the print medium M is not shifted during printing.

  The media moving mechanism 30 includes a cylindrical feed roller 31 that is disposed with its upper peripheral surface exposed to the platen 20 and extends left and right, and a roller drive motor 33 that rotationally drives the feed roller 31 via a timing belt 32. Thus, above the feed roller 31, a plurality of roller assemblies 35 each having a pinch roller 36 that can be rotated back and forth are provided side by side. The roller assembly 35 is configured to be settable to a clamp position where the pinch roller 36 is pressed against the feed roller 31 and an unclamp position separated from the feed roller 31. When the roller drive motor 33 is rotationally driven in a state where M is sandwiched between the pinch roller 36 and the feed roller 31, the rotation angle of the print medium M (drive control value output from the control unit 80). It is transported back and forth with a feed amount according to. In FIG. 3, both the state where the roller assembly 35 is set to the clamp position and the state where it is set to the unclamp position are shown.

  The carriage 40 is supported by a guide rail 45 extending in parallel with the feed roller 31 and attached to the upper frame 10U so as to be movable left and right via a slide block (not shown). Driven. The carriage 40 is provided with a printer head 60 that discharges UV ink, and the nozzle surface at the lower end of the head is disposed to face the media support portion 21 of the platen 20 with a predetermined gap therebetween.

  In general, the printer head 60 includes a number of printer heads arranged side by side according to the quantity of ink used in the printer apparatus P. For example, cyan (C), magenta (M), and yellow (Y). In the case of a printer apparatus that uses one ink cartridge for each of the four basic colors of black (K) UV ink, 4 corresponding to each ink cartridge is shown in FIG. Two printer heads 60 (first printer head 60C, second printer head 60M, third printer head 60Y, fourth printer head 60K) are provided. In the carriage 40, sub tanks 120 (first sub tank 120C, second sub tank 120M, third sub tank 120Y, and fourth sub tank 120K) of the ink supply apparatus 100 described in detail later correspond to the printer heads 60C, 60M, 60Y, and 60K. Is provided. As shown in FIGS. 6 and 7, a filter assembly 61 including a filter 61 b and a filter holding member 61 a that holds the filter 61 b is attached to the upper surface of the printer head 60. The filter 61b filters the UV ink sent from the sub tank 120, and the UV ink filtered by the filter 61b is sent to the ink chamber of the printer head 60. Note that the printer head 60 in the present embodiment exemplifies a configuration that ejects ink by a piezo method.

  On the left and right sides of the carriage 40, a UV light source is provided for irradiating the UV ink discharged from the printer head 60 onto the printing medium M with ultraviolet light and curing it. The UV light source includes a left UV light source 70L provided on the left side of the carriage 40 and a right UV light source 70R provided on the right side of the carriage 40. These left and right UV light sources 70L and 70R are provided on the carriage 40. The first to fourth printer heads 60C, 60M, 60Y, and 60K are disposed so as to be sandwiched from the left and right outer sides. The left UV light source 70L and the right UV light source 70R are configured by using a light source that emits ultraviolet light having a wavelength λ = 100 to 380 nm, for example, a UV lamp, a UV-LED, or the like. The blinking operation of the left and right UV light sources 70 </ b> L and 70 </ b> R is controlled by the control unit 80 in accordance with the movement of the carriage 40 by the carriage drive mechanism 50 and the ejection of ink from the printer head 60.

  The carriage moving mechanism 50 includes a driving pulley 51 and a driven pulley 52 provided on the left and right sides of the frame 10 with the guide rail 45 interposed therebetween, a carriage driving motor 53 that rotates the driving pulley 51, and a driving pulley 51 and a driven pulley 52. And an endless belt-like timing belt 55 wound around the belt. The carriage 40 is connected and fixed to a timing belt 55, and the carriage 40 supported by the guide rail is rotated by the rotation of the carriage drive motor 53. The rotation angle of the carriage drive motor 53 (the drive output from the control unit 80). The platen 20 is moved left and right by a movement amount corresponding to the control value.

  The control unit 80 includes a ROM 81 in which a control program for controlling the operation of each unit of the printer device is written, a RAM 82 for temporarily storing a print program for drawing on the print medium M, a print program read from the RAM 82, and an operation panel 88. An arithmetic processing unit 83 that performs arithmetic processing on the input operation signal and the like and controls the operation of each unit according to the control program, an operation panel 88 provided with a display panel and various operation switches for displaying the operating state of the printer device P, etc. The medium moving mechanism 30 moves the print medium M back and forth, the carriage moving mechanism 50 moves the carriage 40 left and right, the ink supply device 100 supplies ink, the ink is ejected from each nozzle of the printer head 60, and the ink supply device 100. Control ink supply by To.

  For example, when drawing on the print medium M based on the print program read into the control unit 80, the forward / backward movement M of the print medium by the medium moving mechanism 30 and the left / right movement of the carriage 40 by the carriage moving mechanism 50 are combined. The print medium M and the printer head 60 are moved relative to each other so that ink is ejected from each printer head 60 to the print medium M, and a UV light source located behind the carriage 40 in the movement direction (for example, a left UV light source when the carriage moves to the right). 70L) is turned on to draw information according to the printing program.

  In this way, in the printer apparatus P schematically configured, UV ink is supplied from the ink supply apparatus 100 to the printer head 60 provided in the carriage 40. 4 is a system diagram of the ink supply device 100, FIG. 6 is an external perspective view of the sub-tank 120, FIG. 7 is a cross-sectional view of the VII-VII portion in FIG. 6, and FIG. 8 is a VIII-VIII portion in FIG. FIG. 9 is a schematic block diagram of the ink supply device 100.

  The ink supply device 100 includes a sub-tank 120 connected to the printer head 60, a main tank 110 connected to the sub-tank 120 and storing UV ink supplied to the sub-tank 120, and a sub-tank decompression that reduces the internal pressure of the sub-tank 120 to a negative pressure state. Unit 140, a sub tank pressurizing unit 150 that pressurizes the internal pressure of the sub tank 120 to a positive pressure state, an ink transfer unit 115 that transfers UV ink stored in the main tank 110 to the sub tank 120, and the like. The pressure unit 150 includes a single air pump 160.

  The main tank 110 is set so as to store UV ink having a capacity corresponding to the ink consumption per unit time in the printer device P. In the present embodiment, for the four colors C, M, Y, and K described above, the cartridge type main tank 110 (first main tank 110C, second main tank 110M, third main tank 110Y, capacity of about 500 ml for each color). A configuration example is shown in which a fourth main tank 110K) is used and these main tanks 110 are detachably disposed on the back surface of the apparatus main body 1 (see FIG. 2). With this configuration, the large main tank 110 can be disposed at any position in the apparatus main body 1 within the range of the head of the liquid feed pump 118 described later, and the printer P can be downsized. . Further, the main tank 110 can be easily replaced by arranging the main tank 110 at a position where it can be easily reached by an operator. The main tank 110 may have another form such as a cylindrical container or a flexible bag. The ink tank may be disposed at the front side or upper part of the apparatus main body 1 or the apparatus main body 1. It can be arranged appropriately, such as separately.

  As shown in FIG. 6, the sub-tank 120 is opened to the side (right) and is closed so as to cover the thin rectangular box-shaped container member 121 that is long in the vertical direction in a side view and the opening surface of the container member 121. An ink storage chamber 123 for storing UV ink is formed inside a tank formed by closing the cover member 122. In addition, a groove-like float housing portion 124 that communicates with the ink storage chamber 123 and extends vertically at the rear portion of the ink storage chamber 123 is formed. In the float accommodating part 124, a disc-shaped float 134 that has a magnet 134a fixed at the center and floats on the UV ink is accommodated so as to be movable up and down. In the present embodiment, when UV ink having a specific gravity of, for example, about 1.0 is used, it is preferable that the float 134 has a specific gravity of, for example, about 0.25 that floats in the UV ink.

  The sub tank 120 is joined integrally by applying a sealant or an adhesive to the opening edge surface of the container member 121 and closing the lid member 122, and is firmly joined by a fastening means such as a screw (not shown). The storage chamber 123 is kept sealed. At least one of the lid member 122 and the container member 121 is formed using a transparent or translucent material, and the external storage state of the UV ink in the ink storage chamber 123, the floating state of the float 134 in the UV ink, and the like are external. It is configured so that it can be visually confirmed. For example, a transparent film can be used as the lid member 122. In this case, the ink storage chamber 123 is held in a sealed state by welding the transparent film to the container member 121.

  A short cylindrical connector part 125 projecting downward from the bottom wall 121b of the container member 121 is formed on the lower surface side of the sub tank 120, and a connector space 125a opened downward is formed inside the connector part 125. Has been. A block-shaped duct portion 126 extending upward from the bottom wall 121b through the ink storage chamber 123 is formed above the connector portion 125. Then, a first lead-out path 127a that penetrates the bottom wall 121b up and down and connects the bottom surface of the ink storage chamber 123 and the connector space 125a is formed, and penetrates the duct portion 126 and the bottom wall 121b up and down to form the duct portion 126. A second lead-out path 126b that connects the upper surface 126a and the connector space 125a is formed. The connector portion 125 and the filter assembly 61 are connected using a tube 69, and a tube space 69 a is formed inside the tube 69. Therefore, the ink storage chamber 123 of the sub tank 120 and the ink chamber of the printer head 60 are connected via the first lead-out path 127a, the second lead-out path 126b, the connector space 125a, and the tube space 69a. Here, the cross-sectional area of the first lead-out path 127a is formed smaller than the cross-sectional area of the second lead-out path 126b. In the state where the carriage 40 is positioned at a reference position (so-called home position) at the time of non-printing, a pad-shaped ink tray 180 for receiving UV ink is provided below the printer head 60 (60C, 60M, 60Y, 60K). Provided (see FIG. 5).

  On the rear side of the sub tank 120, a sub tank storage detection unit 130 that detects the storage state of the UV ink in the ink storage chamber 123 is provided. The sub-tank storage detection unit 130 is accommodated in a float accommodation unit 124 that extends vertically so as to freely move up and down, and a float 134 that moves up and down together with the liquid level of the UV ink in the ink storage chamber 123, and is fixed to the float 134. The liquid level detection sensor 138 detects the liquid level height of the UV ink by detecting the magnetism of the magnet 134a. The liquid level detection sensor 138 is configured such that a liquid level detection substrate 135 to which a Hi detection sensor 136H and a Lo detection sensor 136L capable of detecting the magnetism of the magnet 134a are attached is accommodated in a case member 137. Here, the Hi detection sensor 136H and the Lo detection sensor 136L can be configured using, for example, a Faraday element, a magnetic impedance element, or the like, and a Hall element is preferably used. Various magnets can be used as the magnet 134a, and an anisotropic ferrite magnet is preferably used.

  A groove-shaped sensor mounting portion 131 that extends vertically is formed on the rear wall 121r of the container member 121, and the liquid level detection sensor 138 is inserted into the sensor mounting portion 131. Then, as shown in FIG. 7, for example, the liquid level detection sensor 138 is attached and fixed to the rear wall 121 r by inserting and fastening the attachment screw 139 into the attachment hole 137 a of the case member 137. In a state where the liquid level detection sensor 138 is mounted and fixed, the Hi detection sensor 136H can detect that the liquid level of the UV ink in the ink storage chamber 123 has reached the highest position (filling reference height (Middle)). It has. On the other hand, the Lo detection sensor 136L has a function capable of detecting that the liquid level of the UV ink in the ink storage chamber 123 has reached the lowest position (minimum reference height (Low)).

  Further, as shown in FIG. 7, the liquid level detection sensor 138 is disposed opposite the float 134 with the rear wall 121r interposed therebetween, and the magnetism of the magnet 134a fixed to the float 134 is detected by the Hi detection sensor 136H or the Lo detection sensor 136L. By detecting at this point, the height position of the float 134, that is, the liquid level height of the UV ink stored in the ink storage chamber 123 can be detected. Further, as can be seen from FIG. 7, the inner wall of the float accommodating portion 124 and the front and rear side surfaces of the float 134 (magnet 134a) are close to each other. Therefore, the float 134 is arranged in accordance with the liquid surface height of the UV ink. 124 is movable up and down substantially straight. With this configuration, the liquid level height of the UV ink in the ink storage chamber 123 is detected by the liquid level detection sensor 138, and the detection result is output to the control unit 80.

  In the present embodiment, the configuration using the Hi detection sensor 136H and the Lo detection sensor 136L is illustrated, but for example, a configuration in which three or more detection sensors are arranged vertically on the liquid level detection substrate 135 may be used. With this configuration, the liquid level detection sensor 138 can finely detect the liquid level height position of the UV ink in the ink storage chamber 123. Then, based on the detected liquid level height position, for example, after grasping the temporal transition of the remaining amount of UV ink, it is possible to control the operator to notify the operator of the next process that is predicted to be necessary. .

  On the front side of the sub tank 120, as shown in FIG. 7, an ink introduction path that penetrates the front wall 121f of the container member 121 back and forth is formed at a predetermined height position between the upper and lower sides, and a tube connected to the ink introduction path A connector 128 is provided. Further, on the upper surface side of the sub tank 120, a gas introduction path that penetrates the ceiling wall 121t of the container member 121 up and down is formed, and a tube connector 129 in which a gas introduction hole 129a is formed in the center portion is provided in the gas introduction path. It is connected.

  Further, as shown in FIG. 7, a backflow prevention unit 132 is formed in the ink storage chamber 123 below the tube connector 129. The backflow prevention part 132 is mainly composed of a float support part 132a and a sealing float 133. The float support portions 132a are paired in the front-rear direction, and each of the vertical portions 132e extends downward from the lower surface of the ceiling wall 121t, and the leading ends thereof are bent back and forth to form locking ribs 132b. The locking ribs 132a and 132b are positioned with a rib gap 132c in the front-rear direction, and the float support part 132a has a left-right gap 132d between the lid member 122 as shown in FIG. The sealing float 133 is housed in a sealing float housing part 132f which is surrounded by a pair of front and rear float support parts 132a and extends vertically, and is movable up and down. Further, when the sealing float 133 is raised to the upper limit position in the sealing float accommodating portion 132f, the sealing float 133 is brought into contact with the lower end opening of the gas introduction hole 129a so as to block the gas introduction hole 129a. Is formed. The pressure control of the ink storage chamber 123 by the subtank decompression unit 140 described later is performed by sucking the air in the ink storage chamber 123 mainly through the left and right gaps 132d and into the gas introduction hole 129a. Further, the pressure control of the ink storage chamber 123 by the sub tank pressurizing unit 150 described later is performed by allowing air to flow into the ink storage chamber 123 from the gas introduction hole 129a mainly through the left and right gaps 132d. In addition, a configuration using a sealing float 133 having a specific gravity of about 0.25, for example, is preferable.

  The ink transfer unit 115 is formed by a main supply circuit 116 that connects between the main tank 110 and the sub tank 120. The main supply circuit 116 is provided in the main body 110 and provided in the main body 110 of the apparatus main body 1, the ink suction line 117 a connected to the main tank 110 and the liquid feed pump 118, the ink delivery line 117 b connected to the liquid feed pump 118 and the tube connector 128. A liquid feed pump 118 that supplies UV ink stored in the tank 110 to the sub tank 120 is configured. The liquid feed pump 118 is a pump that can pump UV ink to the sub tank 120 even when the ink suction line 117a is not filled with UV ink and air is mixed therein. For example, a tube pump or a diaphragm pump is preferably used. .

  The sub tank pressure reducing unit 140 is formed by a negative pressure circuit 141 that connects between the sub tank 120 and the suction port 161 of the air pump 160. The negative pressure circuit 141 includes an air chamber 142 constituted by an airtight container, a pressure sensor 144 for detecting the pressure of the negative pressure circuit 141, and a negative pressure circuit as shown in FIG. A negative pressure control valve 145 that opens and closes 141, and a line 147 (147a, 147b, 147c, 147d) formed by a tube connecting these devices to connect between the suction port 161 of the pneumatic pump and the sub tank 120, etc. Consists of In FIG. 4, a portion surrounded by a frame C is provided on the carriage 40, and a portion outside the frame is a device provided on the apparatus main body 1.

  The air chamber 142 is connected to the suction port 161 of the air feed pump 160, and the air in the chamber is exhausted by the operation of the air feed pump 160 to be reduced to a negative pressure state. The air chamber 142 is provided with an air introduction line 147i for introducing air into the chamber that has been decompressed to a negative pressure state. The air introduction line 147i is provided with a flow rate adjustment valve 143a for adjusting the flow rate of air and an air filter 143b for dust removal. The flow rate adjustment valve 143a makes the internal pressure of the air chamber 142 constant by adjusting the flow rate of the air flowing into the air chamber 142 in a state where the air pump 160 and the sub tank 120 are connected via the negative pressure circuit 141. . As a result, the internal pressure of the ink storage chamber 123 becomes a predetermined negative pressure (for example, negative pressure of -1.2 kPa: hereinafter referred to as “set negative pressure”) appropriate for forming a meniscus in the nozzle portion. Is set as follows.

  The negative pressure control valve 145 is provided between the air chamber 142 and the sub tank 120 and is provided in the carriage 40, and is an electromagnetic valve that switches the line 147c and the line 147d between a communication state and a cutoff state. In this embodiment, a configuration using a three-way valve as the negative pressure control valve 145 is illustrated, and a line 147c is connected to the common port (COM) of the negative pressure control valve 145, and a line 147d is connected to the normal open port (NO). The normally closed port (NC) is open to the atmosphere via the line 147x and the silencer 148.

  For this reason, when the negative pressure control valve 145 is off (during normal operation such as printing or standby, and at the time of ink filling), the line 147c and the line 147d are connected to bring the negative pressure circuit 141 into a communication state. The suction port 161 and the sub tank 120 are connected via a junction circuit 171 described later. On the other hand, when the negative pressure control valve 145 is on (during cleaning or the like), the connection between the line 147c and the line 147d is disconnected and the negative pressure circuit 141 is shut off, and the line 147c is connected to the line 147x, and air is fed. The circuit on the suction port side of the pump 160 is opened to the atmosphere. The negative pressure control valve 145 is connected to the control unit 80 and is on / off controlled by the control unit 80.

  The pressure sensor 144 has a detection region of about ± 5 kPa, and is a gauge pressure type pressure sensor provided between the air chamber 142 and the negative pressure control valve 145, and detects the pressure of the line 147 near the sub tank. A detection signal of the pressure sensor 144 is input to the control unit 80.

  The sub tank pressurizing unit 150 is formed by a positive pressure circuit 151 that connects between the sub tank 120 and the discharge port 162 of the pneumatic pump 160. The positive pressure circuit 151 includes a flow rate adjustment valve 153a for adjusting the flow rate of air, an air filter for dust removal 153b, and a positive pressure circuit 151, as shown in FIG. This is formed by a pressure sensor 154 for detecting the pressure of the gas, a positive pressure control valve 155 for opening and closing the positive pressure circuit 151, and a tube connecting these devices to connect the discharge port 162 of the air pump 160 and the sub tank 120. Line 157 (157a, 157b, 157c, 157d) and the like. The flow rate adjustment valve 153a increases the internal pressure of the ink storage chamber 123 to a predetermined level or more by adjusting the flow rate of air flowing through the positive pressure circuit 151 in a state where the air feed pump 160 and the sub tank 120 are connected by the positive pressure circuit 151. This valve is adjusted so that it does not.

  The positive pressure control valve 155 is provided in the carriage 40 so as to be positioned between the flow rate adjustment valve 153a and the sub tank 120, and is an electromagnetic valve that switches the line 157c and the line 157d between a communication state and a cutoff state. In this embodiment, a configuration using a three-way valve as the positive pressure control valve 155 is illustrated, and a line 157c is connected to the common port (COM) of the positive pressure control valve 155, and a line 157d is connected to the normal close port (NC). The normal open port (NO) is open to the atmosphere via the line 157x and the silencer 158.

  For this reason, when the positive pressure control valve 155 is off (during normal operation such as printing or standby, and at the time of ink filling), the connection between the line 157c and the line 157d is disconnected and the positive pressure circuit 151 is cut off. In addition, the line 157c is connected to the line 157x, and the positive pressure circuit on the discharge port side of the air feed pump 160 is opened to the atmosphere. On the other hand, when the positive pressure control valve 155 is on (for cleaning or the like), the line 157e and the line 157d are connected, the positive pressure circuit 151 is set in a communication state, and the discharge port 162 and the sub tank 120 are connected to the junction circuit 171. Connected through. The positive pressure control valve 155 is connected to the control unit 80 and is on / off controlled by the control unit 80.

  The pressure sensor 154 is a gauge pressure type pressure sensor provided in the carriage 40 having a detection region of about ± 50 kPa, and detects the pressure of the line 157 near the sub tank. A detection signal of the pressure sensor 154 is input to the control unit 80.

  The pneumatic pump 160 is a pump that sucks air from the negative pressure circuit 141 connected to the suction port 161 and pumps the sucked air to the positive pressure circuit 151 connected to the discharge port 162. A pump that generates a predetermined positive / negative pressure at the port 161 is used. For example, a diaphragm pump that generates a positive / negative pressure of about ± 40 kPa is preferably used.

  The negative pressure circuit 141 and the positive pressure circuit 151 merge on the way to the sub tank 120, and a merge circuit 171 is formed. The junction circuit 171 includes a line 177 formed by joining the line 147d and the line 157d and connected to the sub tank, and a junction circuit opening / closing valve 175 that opens and closes the junction circuit 171. The junction circuit open / close valve 175 is provided corresponding to the number of sub-tanks 120. In this embodiment, the junction circuit open / close valve 175 is divided into four junction circuits 171 (line 177). The case where each junction circuit (lines 177C, 177M, 177Y, 177K, part number omitted) is configured to be individually openable and closable is illustrated. The operation of the junction circuit opening / closing valve 175 is controlled by the control unit 80.

  In the ink supply device 100 configured as described above, the operation of the liquid feed pump 118, the negative pressure control valve 145, the positive pressure control valve 155, and the air feed pump 160 is controlled by the control unit 80 as follows. . As is clear from the above description, the UV ink supply system is the same for the four systems (C, M, Y, K). The description is omitted.

(Control during normal operation)
When the main power supply of the printer device P is turned on, the control unit 80 reads the control program stored in the ROM 81 and controls the operation of each part of the printer device based on the read control program. For the ink supply device 100, electric power is supplied to the air feed pump 160 to be in a rotational drive state, and all the junction circuit open / close valves 175 are turned on. At this time, it is preferable to turn on all the junction circuit opening / closing valves 175 after the internal pressure of the sub tank is maintained at a negative pressure (that is, both the negative pressure control valve 145 and the positive pressure control valve 155 are off). Then, after the junction circuit opening / closing valve 175 is turned on, both the negative pressure control valve 145 and the positive pressure control valve 155 remain off. As a result, in the negative pressure circuit 141, the line 147c and the line 147d are communicated to connect the suction port 161 and the ink storage chamber 123, and in the positive pressure circuit 151, the line 157c and the line 157x are connected to each other, and the air feed pump The circuit on the discharge port side of 160 is opened to the atmosphere. For this reason, the air in the line 147 connected to the suction port 161 is sucked to depressurize the air chamber 142 to a negative pressure, and the inflow air flow rate adjusted by the flow rate adjusting valve 143a and the air sucked by the air pump 160 Stable at a substantially constant pressure determined by the balance with the amount. Here, the internal pressures of the ink storage chambers 123 of the four sub-tanks are stably held in a state where all are set to the same set negative pressure. When the printer device P is started in this manner, the air feed pump 160 is continuously operated thereafter, and the internal pressure of the sub tank 120 is constantly maintained at the set negative pressure regardless of whether the printing program is being executed or is on standby.

  During normal operation, UV ink is stored to some extent in the ink storage chamber 123 of the sub tank 120. The amount of UV ink stored is such that the magnet 134a fixed to the float 134 that moves up and down together with the UV ink level is detected by the Hi detection sensor 136H, and the UV ink level in the ink storage chamber 123 is at the highest position. It is possible to detect that (filling reference height) has been reached ("Middle" state). On the other hand, the magnetism of the magnet 134a is detected by the Lo detection sensor 136L, and it can be detected that the surface of the UV ink in the ink storage chamber 123 has reached the lowest position (minimum reference height) ("" Low state).

  The UV ink stored in the ink storage chamber 123 is discharged and consumed from the nozzles of the printer head 60 by executing a printing program or the like, and the stored UV ink gradually decreases. When the UV ink stored in the ink storage chamber 123 falls below a predetermined amount, the UV ink stored in the main tank 110 is supplied to the sub tank 120 by the ink transfer unit 115 and replenished with UV ink.

In the conventional ink remaining amount monitoring method, specifically, when the UV ink stored in the ink storage chamber 123 decreases, the liquid level of the UV ink decreases, and the float 134 also floats according to the liquid level. The part 124 is moved downward. When the residual amount of UV ink becomes equal to or less than a predetermined amount, the magnetism of the magnet 134a fixed to the float 134 is detected by the lowest position Lo detection sensor 136L.
Upon receiving the detection signal from the liquid level detection sensor 138, the control unit 80 activates the liquid feed pump 118 in a state where the ink storage chamber 123 is depressurized to a negative pressure state. The UV ink delivered from the main tank 110 by the liquid feed pump 118 is supplied from the tube connector 128 to the ink storage chamber 123 through the line 117b, and the amount of stored ink in the ink storage chamber 123 increases.
At this time, as the amount of stored ink increases, the liquid level of the UV ink increases, and the float 134 is also moved upward in the float accommodating portion 124 according to the liquid level. Then, when the magnetism of the magnet 134a fixed to the float 134 is detected by the Hi detection sensor 136H at the highest position, the liquid feed pump 118 is stopped, whereby the replenishment of the UV ink to the ink storage chamber 123 is completed.

By the way, the float 134 and the magnet 134a may not follow the UV ink liquid level for some reason, or the UV ink liquid level detected from the height of the float 134 and the magnet 134a may not match the actual UV ink residual amount. is there.
For example, it is assumed that the float 134 and the magnet 134a do not move due to some cause in the float accommodating portion 124 while being positioned at a vertical height of a predetermined amount or less. As described above, the control unit 80 operates the liquid feed pump 118 until the magnetism of the magnet 134a is detected by the Hi detection sensor 136H. For this reason, there is a possibility that the UV ink continues to be supplied even after the filling reference height is exceeded, and the UV ink flows into the gas introduction hole 129a and flows backward.

In addition, other causes of erroneous detection of the UV ink liquid level include, for example, when the float member 134 sticks to the wall surface of the sub tank 120 (float housing portion 124), nozzle omission, ink leakage, UV ink inflow due to aging, and the like. Can be mentioned.
In the case of missing nozzles, even if the ink is ejected, it is not actually ejected. In FW (Firmware), it is determined that the ink has been consumed by issuing an ink ejection command, but the ink is actually consumed. Not. In this case, the height of the magnet 134a is the reference filling height (Middle), and the remaining amount of UV ink is “low”.
Ink leakage is a state in which UV ink is leaking from the sub tank 120 (ink storage chamber 123), and although ink is not consumed by the FW, ink is actually consumed. In this case, the height of the magnet 134a is the minimum reference height (Low), and the remaining amount of UV ink is “no change”.
Ink inflow due to aging causes UV ink to flow into the sub tank 120 (ink storage chamber 123) as the slider swings from side to side. In this case, the UV ink does not flow because the FW does not rotate the pump. However, in reality, there is a risk of UV ink flowing in. In this case, the height of the magnet 134a is the reference filling height (Middle), and the remaining amount of UV ink is “no change”.

Therefore, in the present invention, in the ink remaining amount control in the sub tank 120, the float does not follow the UV ink liquid surface for some reason, such as the float sticking to the inner wall surface of the sub tank 120 (float container 124), or the magnet 134a Even if the UV ink liquid level detected from the height does not match the actual remaining amount of UV ink, monitoring by FW is strengthened so that the sent UV ink does not flow into the air path, I was able to respond to the situation.
That is, in the present invention, in the ink replenishment control during printing, (1) the conditions for starting the ink supply to the sub tank are tightened. (2) Clarification of calculation of ink feeding time to sub tank. (3) The ink consumption was updated after the ink was sent to the sub tank, and the error occurrence requirements after ink replenishment were clarified.
In the following description, “the height of the magnet 134a (liquid level indicating member) is the minimum reference height (Low)” means “the magnet of the magnet 134a (liquid level indicating member) fixed to the float 134”. Is detected by the lowest position Lo detection sensor 136L ”. Further, “the height of the magnet 134a (liquid level indicating member) is the filling reference height (Middle)” means that “the magnetism of the magnet 134a fixed to the float 134 is detected by the Hi detection sensor 136H at the highest position. It means “what has been done”.

Specifically, first, regarding (1) the condition for starting the ink feeding to the sub tank 120, conventionally, the magnet monitoring is performed every predetermined time, and conventionally, the minimum reference height (Low) is continuously set three times. When detected, ink feeding was started. Further, if the height of the magnet 134a is still the minimum reference height (Low) even after ink feeding, an error is determined.
On the other hand, in the present invention, ink feeding is started when the above-described conventional detection method and the remaining amount of UV ink calculated based on the ink consumption amount becomes a predetermined amount (for example, 50%) or less. To do. In this way, by tightening the ink feeding start condition, it is possible to prevent ink feeding even when the float sticks to the lower side, for example.

(2) Regarding the calculation of the ink feeding time to the sub tank 120, conventionally, the liquid feeding pump is used for the maximum time specified by the parameter until the height of the magnet 134a reaches the filling reference height (Middle). Was turning.
On the other hand, in the present invention, the amount of liquid that can be fed is calculated until the height of the magnet 134a reaches the filling reference height (Middle), and the maximum rotation time of the liquid feeding pump 118 is calculated from the calculation result, The liquid feed pump 118 is rotated for the calculated time. Thereby, the ink feeding time is clarified, and it is possible to prevent the UV ink from being fed excessively to the sub tank 120.

In addition, regarding (3) renewal of ink consumption after liquid supply (error generation requirement after ink replenishment), conventionally, an error is determined if the minimum reference height (Low) is present even after ink replenishment. It was.
On the other hand, in the present invention, after the ink is supplied by replenishment, if the height of the magnet 134a is the reference filling height (Middle), it is determined that the remaining amount of UV ink is full (for example, 100%). After ink supply by replenishment after pressurization, if the height of the magnet 134a is the minimum reference height (Low), an error is determined. This makes it easier to find the occurrence of an error after ink feeding.

  As described above, according to the present invention, in the ink remaining amount control in the sub tank 120, in addition to the detection of the UV ink liquid level based on the height of the magnet 134a fixed to the float 134, the UV ink remaining amount based on the ink consumption amount is also combined. Therefore, the float 134 and the magnet 134a do not follow the UV ink level for some reason, such as the float in the sub tank 120 sticks to the inner wall surface of the tank, or is detected from the height of the magnet 134a. Even when the UV ink liquid level and the UV ink remaining amount calculated based on the ink consumption amount do not match, erroneous detection of the liquid level can be prevented. As a result, in the present invention, even if the UV 134 liquid level height cannot be normally detected by the magnet 134a fixed to the float 134, the supplied UV ink flows into the gas introduction hole 129a. A situation such as backflow can be prevented in advance.

FIG. 10 is a flowchart showing an outline of monitoring the remaining amount of ink in the sub tank during printing according to the present invention.
In this ink remaining amount monitoring method, step 1 (S1) for detecting the height of the float 134 (and magnet 134a) in the sub tank 120, step 2 (S2) for calculating the remaining amount of UV ink in the sub tank 120, Step 3 (S3) for feeding ink into the sub tank 120 according to the results of Step 1 and Step 2, and Step 4 (S4) for calculating the height of the float 134 (and magnet 134a) in the sub tank 120; Are provided at least in order.
Hereinafter, it demonstrates in order of a step.

(1) The height of the magnet 134a fixed to the float 134 in the sub tank 120 is detected (step 1).
Specifically, when the UV ink stored in the ink storage chamber 123 of the sub tank 120 decreases, the liquid level height of the UV ink decreases, and the float 134 moves downward in the float accommodating portion 124 according to the liquid level height. Is done. When the liquid surface height of the UV ink becomes equal to or lower than the predetermined minimum reference height, the magnetism of the magnet 134a fixed to the float 134 is detected by the lowest position Lo detection sensor 136L.

(2) The remaining amount of ink in the sub tank 120 is calculated (step 2).
Next, the remaining amount of UV ink in the sub tank 120 is calculated. Here, the UV ink remaining amount is obtained from the UV ink consumption in the sub tank 120.
The UV ink consumption in the sub tank 120 includes (a) ink ejection by drawing / flushing and (b) purge by filling / cleaning. In the case of (a), the consumption amount is the number of ejected dots × dot volume, and in the case of (b), it depends on the purge time.

(3) Ink is fed into the sub tank 120 in accordance with the results of Step 1 and Step 2 (Step 3).
Based on the height of the magnet 134a detected in step 1 and the result of the remaining amount of UV ink calculated in step 2, it is determined whether or not UV ink is fed to the sub tank 120 or whether an error has occurred. .
Specifically, when the height of the magnet 134a detected in Step 1 is the minimum reference height (Low) and the remaining amount of UV ink calculated in Step 2 is less than the threshold value, the UV ink is fed. Start.
Here, the threshold value is a numerical value that does not prevent ink ejection in time even if the ink ejection speed is considered, if ink feeding is started when that value is reached. it can. That is, the threshold value is a value determined from the relationship between the ink consumption speed from the nozzles and the ink remaining amount in the sub tank, and the ink storage capacity (capacity) of the sub tank. An example of the threshold value is, for example, a numerical value of 50%, but is not particularly limited. Other examples of the threshold include 40%, 45%, 55%, and 60%, for example.

The height of the magnet 134a detected in step 1 is not the minimum reference height (Low) (no detection by the Lo detection sensor 136L), and the UV ink remaining amount calculated in step 2 is less than the threshold value. If so, an error is determined (S3-1). The cause of the error in this case is considered to be float upper sticking, nozzle missing, or error (displacement between the discharge amount and the calculated value at the stroke). At this time, if the UV ink remaining amount condition is less than 20%, more accurate determination can be made.
If the height of the magnet 134a detected in step 1 is the minimum reference height (Low) and the remaining amount of UV ink calculated in step 2 is greater than or equal to the threshold value, an error is determined (S3-2). . The cause of the error in this case is considered to be sticking on the lower side of the float, a failure of the liquid feed pump, or ink shortage of the supply source. At this time, if the UV ink remaining amount condition is 80% or more, more accurate determination can be made.
The height of the magnet 134a detected in step 1 is not the minimum reference height (Low) (no detection by the Lo detection sensor 136L), and the UV ink remaining amount calculated in step 2 is greater than or equal to the threshold value. In this case, UV ink feeding is not performed.

Then, only when the height of the magnet 134a detected in Step 1 is the minimum reference height (Low) and the remaining amount of UV ink calculated in Step 2 is less than the threshold value, the sub tank 120 is transferred to. Ink feeding (replenishment).
In this way, in addition to detecting the height of the magnet 134a, the remaining amount of UV ink based on the ink consumption amount is also determined as to whether or not ink feeding (replenishment) is necessary, so that it is detected from the height of the magnet 134a. Even if the UV ink liquid level and the remaining amount of UV ink calculated based on the ink consumption do not match, the possibility of erroneous detection of the liquid level can be greatly reduced.

Then, the control unit 80 calculates the amount of liquid that can be fed until the height of the float 134 (magnet 134a) reaches the filling reference height, and calculates the maximum rotation time of the liquid feeding pump 118 from the calculation result, The ink feeding is performed by turning the liquid feeding pump 118 for the calculated time.
The liquid feeding time (pump rotation time) is obtained by, for example, (liquid feeding possible amount) / (liquid feeding amount per unit time).
The control unit 80 activates the liquid feed pump 118 in a state where the ink storage chamber 123 is depressurized to a negative pressure state. The UV ink delivered from the main tank 110 by the liquid feed pump 118 is supplied from the tube connector 128 to the ink storage chamber 123 through the line 117b, and the amount of stored ink in the ink storage chamber 123 increases.
At this time, as the amount of stored ink increases, the liquid level of the UV ink increases, and the float 134 and the magnet 134a are also moved upward in the float accommodating portion 124 according to the liquid level.

(4) After a predetermined time has elapsed after completion of ink feeding, the height of the magnet 134a in the sub tank 120 is detected (step 4).
After the liquid feed pump 118 stops rotating, the height of the magnet 134a in the sub tank 120 is detected as an intermediate remaining amount monitor.
Then, when the detected height of the magnet 134a is not the lowest reference height (Low) continuously for a predetermined time (for example, 1 second) (when no detection is performed by the Lo detection sensor 136L) or has been detected. When the height of the magnet 134a is the reference filling height (Middle), the remaining amount of UV ink is changed to a fully filled state (for example, 100%) as ink replenishment success (S5). Thereafter, the process returns to the normal remaining amount monitoring.
On the other hand, when the detected height of the magnet 134a is the minimum reference height (Low) continuously for a predetermined time (for example, 1 second), it is determined that there is an ink refill error (refill failure) (S6).

  As described above, in the ink remaining amount monitoring method of the present invention, in addition to the detection of the UV ink liquid level based on the height of the magnet 134a fixed to the float 134, the monitoring is strengthened together with the ink remaining amount based on the ink consumption amount. Therefore, for some reason, the float 134 and the magnet 134a do not follow the ink liquid level, or the UV ink remaining level calculated based on the UV ink liquid level detected from the height of the magnet 134a and the ink consumption amount. Even when the amounts do not match, erroneous detection of the liquid level can be prevented. Further, in the present invention, by detecting the UV ink liquid level based on the height of the magnet 134a and monitoring the remaining amount of UV ink based on the ink consumption, the cause of any error can be easily detected. It is possible to infer.

FIG. 11 is a flowchart showing a more detailed process of the remaining ink control according to the present invention.
First, ink feeding, cleaning and filling are performed (S10).
Next, the height of the float 134 (and the magnet 134a) is detected (S11).
When the height of the float 134 detected in S11 is the minimum reference height (Low), the remaining amount of UV ink is calculated from the ink consumption (S12).
If the remaining amount of UV ink calculated in S12 is greater than or equal to the threshold value, an error is determined (S13). The cause of the error in this case is considered to be float sticking or ink leakage.
When the remaining amount of UV ink calculated in S12 is less than the threshold value, the maximum pump rotation time is calculated (S14). Here, the amount of liquid feeding is calculated until the height of the float 134 reaches the filling reference height (Middle), and the maximum rotation time of the liquid feeding pump 118 is calculated from the calculation result.

Thereafter, pump rotation is started (S15). The liquid feed pump 118 is rotated for the maximum rotation time calculated in S14 to feed ink.
Wait for a predetermined time (S16).
Thereafter, the height of the float 134 is confirmed (S17).
When the height of the float 134 is the minimum reference height (Low) in S17, it is confirmed whether or not a certain time (the pump rotation time calculated in S14) has elapsed (S18). If the time is over, the pump rotation is stopped (S19).
On the other hand, when the height of the float 134 is the reference filling height (Middle) in S17, the pump is stopped even within the predetermined time (the pump rotation time calculated in S14) (S19).

After the pump rotation is stopped, the height of the float 134 is confirmed (S20).
If the height of the float 134 detected in S20 is the reference filling height (Middle), it is determined that the ink has been replenished successfully, and the remaining amount of UV ink is changed to a fully charged state (S21). Thereafter, purge is performed for a certain time (S22).
On the other hand, when the height of the float 134 detected in S20 is the minimum reference height (Low) detection, the purge is performed for a predetermined time (S22).

If the height of the float 134 detected in S11 is the reference filling height (Middle), the remaining amount of UV ink is calculated (S23).
If the remaining amount of UV ink is equal to or greater than the threshold value in S24, purge is performed for a predetermined time (S22).
On the other hand, if the remaining amount of UV ink calculated in S23 is less than the threshold value, an error is determined (S24). Possible causes of errors in this case are, for example, float sticking or missing nozzles.
After purging (S22), it waits for a predetermined time (S25), and then wipes (S26).
Then, the height of the float 134 is detected (S27).
When the height of the float 134 detected in S27 is the minimum reference height (Low), the pump rotation is started (S28).

After waiting for a predetermined time (S29), the height of the float 134 is confirmed (S30).
When the height of the float 134 detected in S30 is the filling reference height (Middle), the pump rotation is stopped (S31).
On the other hand, when the height of the float 134 detected in S30 is the minimum reference height (Low), it is confirmed whether or not a certain time has passed (S32). If it is within the time, it waits again (S29).
If the time is exceeded in S32, the pump rotation is stopped (S31).

After stopping the pump rotation, the height of the float 134 is detected (S33).
If the height of the float 134 detected in S33 is the minimum reference height (Low), an error is determined (S34). Possible causes of the error in this case are, for example, sticking to the float low, failure of the liquid feed pump, and insufficient ink in the supply source.
When the height of the float 134 detected in S33 is the filling reference height (Middle), or when the height of the float 134 detected in S27 is the filling reference height (Middle), the liquid is fed for 2 seconds ( S35).
This is the end.

Although the ink remaining amount monitoring method of the present invention has been described above, the present invention is not limited to the above-described example, and can be changed as appropriate without departing from the spirit of the invention.
For example, in the above description, the case where the float (float member) and the magnet (liquid level indicating member) are accommodated in the float accommodating portion 124 in the sub tank provided in the printer apparatus P is described as an example. The present invention is not limited to this. Even when the printer apparatus P does not have the float accommodating portion 124 and the float and the magnet are accommodated in the ink storage chamber 123 of the sub tank 120, the present invention is not limited thereto. The invention is applicable.
In the above description, the case where UV ink is used has been described as an example. However, the present invention is not limited to this, and the present invention can be applied even when other types of ink are used. Applicable.

  The present invention can be widely applied to an ink remaining amount monitoring method using a float in a sub tank.

  P printer device (inkjet printer), 60 printer head (60C: first printer head, 60M: second printer head, 60Y: third printer head, 60K: fourth printer head), 110 main tank (110C: first main Tank, 110M: second main tank, 110Y: third main tank, 110K: fourth main tank), 120 sub tank (120C: first sub tank, 120M: second sub tank, 120Y: third sub tank, 120K: fourth sub tank) ) (Ink supply device), 123 ink reservoir chamber (supply ink chamber), 124 float storage portion (detection ink chamber), 129a gas introduction hole, 131 sensor mounting portion (mounting portion), 134 float (float member), 134a Magnet (liquid level indicating member, magnet , 135 level detecting board (substrate), 136H Hi detection sensor (magnetic sensor), 136L Lo detection sensor (magnetic sensor), 138 liquid level sensor (liquid level detection unit).

Claims (3)

An ink chamber that is connected to a tank that stores liquid ink and a printer head that discharges the liquid ink, temporarily stores the liquid ink that has flowed in from the tank, and then flows out to the printer head; and ink from the tank to the ink chamber A liquid feed pump for feeding liquid;
An ink supply device comprising at least a float member that is accommodated in the ink chamber so as to be movable up and down and floats in liquid ink, and a liquid level indicating member attached to the float member,
An ink remaining amount monitoring method for detecting a liquid level height of ink in the ink chamber by vertically moving the float member and the liquid level indicating member in the ink chamber,
Detecting the height of the liquid level indicating member in the ink chamber;
Step 2 for calculating the remaining amount of ink in the ink chamber based on the ink consumption amount;
Step 3 for feeding ink into the ink chamber according to the results of Step 1 and Step 2;
Step 4 of detecting the height of the liquid level indicating member after a predetermined time has elapsed after completion of ink feeding, at least in order,
Only in the case where the height of the liquid level indicating member detected in the step 1 is equal to or lower than the minimum reference height and the ink remaining amount calculated in the step 2 is less than a threshold value, the step 3 is executed. Start feeding ink,
In step 3, the amount of liquid that can be fed is calculated until the height of the liquid level indicating member reaches the filling reference height, and the maximum rotation time of the liquid feeding pump is calculated from the calculation result, and only the calculation time is calculated. Perform ink feeding by turning the liquid feeding pump,
In the step 4, if the height of the liquid level indicating member is a reference filling height, it is determined that the ink remaining amount is in a fully filled state. The height of the liquid level indicating member detected in step 1 is less than or equal to the minimum reference height, and the ink remaining amount calculated in step 2 is greater than or equal to a threshold value; or
When the height of the liquid level indicating member detected in step 1 is the reference filling height and the remaining ink amount calculated in step 2 is less than a threshold value, an error is determined. The ink remaining amount monitoring method according to claim 1, wherein:   2. The ink remaining amount monitoring method according to claim 1, wherein an error determination is made when the height of the liquid level indicating member detected in the step 4 is not more than a minimum reference height.

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