JP2009023329A - Recording liquid replenishment supply amount control method, recording liquid replenishment supply amount control apparatus, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide very accurate ink supply with a very simple system and accurately control a negative pressure inside a sub tank so as to cause ink outflow from a recording head, deterioration of output image quality, etc. It is possible to prevent problems and to maintain the negative pressure in the recording head without considering the variation in the amount of displacement of the negative pressure lever due to the environmental variation of the sub tank.
According to the recording liquid replenishment supply amount control method of the present invention, when replenishing and supplying recording liquid to a sub tank, the displacement of the negative pressure lever with respect to a predetermined recording liquid suction amount is set to the vicinity of the sub tank. The recording liquid replenishment supply amount is controlled based on the displacement amount of the negative pressure lever multiplied by the correction coefficient corresponding to the environmental characteristic value.
[Selection] Figure 5

Description

  The present invention relates to a recording liquid replenishment supply amount control method, a recording liquid replenishment supply amount control apparatus, and an image forming apparatus. More specifically, the present invention is provided in a subtank that replenishes a recording liquid from a main tank on the apparatus body side to a recording head. The present invention relates to a technique for defining a replenishment supply amount to a sub tank by controlling an opening amount of a negative pressure lever that is displaced according to a storage capacity of the sub tank according to environmental characteristics.

  In an ink jet recording apparatus equipped with an ink cartridge having a large ink capacity, if the ink cartridge is directly mounted on the recording head mounted on the carriage and ink is supplied to the recording head, the carriage operation is caused by the weight of the ink cartridge. It will be a hindrance and image quality will be reduced. Therefore, there has conventionally been an ink jet recording apparatus in which an ink cartridge is mounted on the main body side and a sub tank for temporarily storing ink used for printing is mounted on a recording head in a carriage.

  FIG. 12 is a perspective view showing the structure of the sub tank of the ink jet recording apparatus. In the figure, a negative pressure lever 301 is provided in the sub tank and is displaced according to the consumption of ink stored in the sub tank in which a negative pressure is generated by a spring (not shown) that biases the film 302. This lever operates following the film 302 to be operated. The supply port 303 is a supply port through which ink is supplied from the ink cartridges 110k to 110y of FIGS. 1 and 3 to be described later through the ink supply tube 136 of FIG. The atmosphere release pin 304 is a pin that opens the inside of the sub tank to the atmosphere as necessary. Further, a recording head 305 for ejecting ink droplets is attached below the sub tank.

  In an ink jet recording apparatus in which the amount of movement of the negative pressure lever relative to the ink amount is set to a fixed value in the sub tank of the ink jet recording apparatus, the ink filling is performed while observing the amount of movement of the negative pressure lever. Then, if the movement of the negative pressure lever varies from sub-tank to the sub-tank or due to variations in environmental conditions such as the temperature around the installation, the sub-tank is overfilled or filled to the desired filling amount. The amount of ink is insufficient, the negative pressure in the sub tank is difficult to maintain at a desired value, and the image quality deteriorates and the ink flows out of the recording head due to the weight of the ink. In order to solve these problems, several proposals have been conventionally made.

  In Patent Document 1 as one of them, a pressure sensor is mounted between the ink cartridge and the recording head at a location away from the intermediate tank and the tank, and a negative pressure state inside the recording head is sensed. The structure which maintains a desired negative pressure by moving an intermediate tank up and down is disclosed.

  Further, in Patent Document 2, when the pressure of the main tank chamber is reduced by consuming ink from the sub tank chamber having the meniscus constituent member attached to the main tank chamber for storing ink, the reduced pressure A configuration is disclosed in which ink is automatically supplied from the sub-tank chamber to maintain a desired negative pressure.

Further, in Patent Document 3, ink is filled in a sealed ink tank, and a small hole whose one end is opened to the atmosphere is provided in the ink tank. When the ink in the ink tank is consumed, the air passes through the small hole. A configuration is disclosed that is supplied into the tank and maintains the desired negative pressure in the ink tank.
Japanese Patent Laid-Open No. 2003-341028 Patent No. 3,269,268 Japanese Patent No. 2,898,746

  However, in the above-mentioned Patent Document 1, since the recording head, the intermediate tank, and the pressure sensor are arranged at a distance from each other, the system can be complicated and large. In addition, in the negative pressure maintaining mechanism by moving the intermediate tank up and down, providing a mechanism for moving up and down is another factor that makes the system complicated and large. Furthermore, attaching a pressure sensor leads to high costs. In addition, variation with respect to environmental fluctuations such as the temperature around the installation is not taken into consideration, and it is not possible to cope with use in places where environmental fluctuations are severe. Further, in the above-mentioned Patent Document 2, it is difficult to maintain a desired negative pressure due to deterioration of the meniscus constituent member, and when the tank itself leaks for some reason, there is an inconvenience that the failure cannot be dealt with. It was. In addition, variation with respect to environmental fluctuations such as the temperature around the installation is not taken into consideration, and it is impossible to cope with use in places where environmental fluctuations are severe. Further, in the above-mentioned Patent Document 3, since it is always open to the atmosphere, there has been a problem that it is impossible to cope with the case where the ink is denatured and the tank leaks for some reason. In addition, variation with respect to environmental fluctuations such as the temperature around the installation is not taken into consideration, and it is not possible to cope with use in places where environmental fluctuations are severe.

  The present invention is intended to solve these problems. It is possible to supply ink with a very simple system, and to accurately control the negative pressure inside the sub tank. It is possible to prevent problems such as outflow and degradation of output image quality, and to maintain the negative pressure in the recording head without taking into account variations in the displacement of the negative pressure lever due to environmental changes in the sub tank. It is an object to provide an amount control method, a recording liquid replenishment supply amount control device, and an image forming apparatus.

  In order to solve the above problems, a recording liquid is supplied from a nozzle to a recording head that discharges recording liquid droplets, and a subtank in which the recording liquid is replenished and supplied from a main tank on the apparatus main body side, and is stored in the subtank. An image forming apparatus having one or a plurality of recording head units each having a negative pressure lever provided in a sub-tank, which is displaced according to the amount of the recording liquid, which is supplied from the main tank to the sub-tank. According to the recording liquid replenishment supply amount control method of the present invention, the displacement of the negative pressure lever with respect to the predetermined recording liquid suction amount is changed to the vicinity of the subtank when supplying the recording liquid to the subtank. The recording liquid replenishment supply amount is controlled based on the displacement amount of the negative pressure lever multiplied by the correction coefficient corresponding to the environmental characteristic value. Therefore, it is possible to prevent problems such as recording liquid outflow from the recording head and deterioration of output image quality, and further, negative pressure in the recording head can be avoided without considering variations in the displacement of the negative pressure lever due to environmental changes in the sub tank. Can be maintained.

  According to the recording liquid replenishment supply amount control method of the present invention, when the environmental characteristic value in the vicinity of the subtank exceeds a predetermined reference value, the subtank is opened to the atmosphere, and the initial position of the negative pressure lever at that time When the recording liquid is replenished and supplied to the sub tank, the amount of displacement of the negative pressure lever with respect to the predetermined recording liquid suction amount relative to the initial position of the negative pressure lever is multiplied by a correction coefficient corresponding to the environmental characteristic value. It is characterized in that the recording liquid replenishment supply amount is controlled based on the displacement amount of the negative pressure lever. Therefore, even if there is a special change in the environmental characteristic value, it is possible to prevent problems such as recording liquid outflow from the recording head and deterioration in output image quality, and further, the displacement of the negative pressure lever due to the environmental change of the sub tank. The negative pressure in the recording head can be maintained without considering the amount variation.

  Furthermore, the environmental characteristic value is either the temperature or humidity around the sub-tank, or the temperature and humidity, so that the recording liquid can be replenished and supplied with high precision even in an environment with temperature change and humidity change. it can.

  Further, the correction coefficient is updated as needed, so that the correction coefficient is determined in actual use, so that the correction coefficient can be determined in accordance with the usage status of the apparatus, and a very precise recording liquid replenishment supply can be performed.

  Furthermore, the amount of displacement of the negative pressure lever with respect to the predetermined recording liquid suction amount is a value when a predetermined amount of recording liquid is sucked. By calculating the coefficient for the value, it is possible to supply replenishment of the recording liquid with very precise control with very simple control.

  Further, the displacement amount of the negative pressure lever with respect to the predetermined recording liquid suction amount is a value when a predetermined amount of air is sucked, so that an environmental characteristic value is obtained when air suction is performed to maintain negative pressure. By calculating the coefficient with respect to the above, it becomes possible to replenish and supply a very precise recording liquid with very simple control.

  Further, the amount of displacement of the negative pressure lever corresponding to the ink replenishment supply amount is defined based on the amount of displacement at the time of negative pressure formation. By calculating the coefficient with respect to the value, it is possible to replenish and supply the recording liquid with very high precision with very simple control.

  Further, the operation of supplying and replenishing the recording liquid to the sub tank may be performed during the head cleaning operation.

  Further, the ink replenishment supply amount control device according to another aspect of the invention includes a negative pressure lever displacement amount storage unit that stores a displacement amount of a negative pressure lever corresponding to a predetermined ink amount for replenishing ink to the sub tank, and a temperature near the sub tank. A temperature / correction coefficient storage unit that stores a correction coefficient of the displacement amount of the negative pressure lever with respect to the temperature, a temperature detection unit that detects the temperature around the sub tank, and a negative pressure lever position detection unit that detects the displacement amount of the negative pressure lever And the displacement amount of the negative pressure lever detected by the negative pressure lever position detection unit is multiplied by the correction coefficient read from the temperature / correction coefficient storage unit based on the temperature in the vicinity of the sub-tank detected by the temperature detection unit. And a control unit for controlling the ink replenishment supply amount based on the displacement amount of the negative pressure lever. Therefore, it is possible to prevent problems such as recording liquid outflow from the recording head and deterioration in output image quality, and further, negative pressure in the recording head can be avoided without considering variations in the displacement of the negative pressure lever due to ambient temperature fluctuations of the sub tank. Pressure can be maintained.

  In another aspect of the invention, an ink replenishment supply amount control device includes a negative pressure lever displacement amount storage unit for storing a displacement amount of a negative pressure lever corresponding to a predetermined ink amount for replenishing ink to a sub tank, and a humidity near the sub tank. Humidity / correction coefficient storage unit for storing a correction coefficient for the displacement amount of the negative pressure lever with respect to the humidity, a humidity detection unit for detecting the humidity in the vicinity of the sub tank, and a negative pressure lever position detection unit for detecting the displacement amount of the negative pressure lever And the displacement amount of the negative pressure lever detected by the negative pressure lever position detection unit is multiplied by the correction coefficient read from the humidity / correction coefficient storage unit based on the humidity in the vicinity of the sub tank detected by the humidity detection unit. And a control unit for controlling the ink replenishment supply amount based on the displacement amount of the negative pressure lever. Therefore, it is possible to prevent problems such as recording liquid outflow from the recording head and deterioration of the output image quality, and further, negative pressure in the recording head can be avoided without considering variations in the displacement of the negative pressure lever due to fluctuations in the humidity around the sub tank. Pressure can be maintained.

  Further, the ink replenishment supply amount control device according to another aspect of the invention includes a negative pressure lever displacement amount storage unit that stores a displacement amount of a negative pressure lever corresponding to a predetermined ink amount for replenishing ink to the sub tank, and a temperature near the sub tank. Temperature / correction coefficient storage unit for storing the correction coefficient of the displacement amount of the negative pressure lever with respect to the humidity, correction coefficient storage unit for storing the correction coefficient of the displacement amount of the negative pressure lever with respect to the humidity near the sub tank, and the vicinity of the sub tank Detected by a temperature detector that detects the temperature of the sub-tank, a humidity detector that detects the humidity in the vicinity of the sub tank, a negative pressure lever position detector that detects the amount of displacement of the negative pressure lever, and the negative pressure lever position detector The amount of displacement of the negative pressure lever, the temperature around the sub-tank detected by the temperature detector or the humidity around the sub-tank detected by the humidity detector, Alternatively, based on temperature and humidity, the displacement of the negative pressure lever multiplied by the correction coefficient read from the temperature / correction coefficient storage unit or humidity / correction coefficient storage unit, or from the temperature / correction coefficient storage unit and humidity / correction coefficient storage unit And a control unit that controls the ink replenishment supply amount based on the amount. Therefore, it is possible to prevent problems such as recording liquid outflow from the recording head and deterioration of output image quality, and further, variation in the displacement amount of the negative pressure lever due to ambient temperature variation, ambient humidity variation, or ambient temperature / humidity variation of the sub tank. The negative pressure in the recording head can be maintained without considering the above.

  Also, when the temperature around the sub tank detected by the temperature detection unit exceeds a predetermined reference value, or when the humidity around the sub tank detected by the humidity detection unit exceeds a predetermined reference value Opens the sub-tank to the atmosphere, detects the initial position of the negative pressure lever at that time, and the controller detects the amount of displacement of the negative pressure lever relative to the initial position of the negative pressure lever, the temperature / correction coefficient storage unit or the humidity / correction coefficient storage unit Alternatively, the recording liquid replenishment supply amount is controlled based on the displacement amount of the negative pressure lever multiplied by the correction coefficient read from the temperature / correction coefficient storage unit and the humidity / correction coefficient storage unit. Therefore, even if there is a special change in the environmental characteristic value, it is possible to prevent problems such as recording liquid outflow from the recording head and deterioration in output image quality, and further, the displacement of the negative pressure lever due to the environmental change of the sub tank. The negative pressure in the recording head can be maintained without considering the amount variation.

  The correction coefficients stored in the temperature / correction coefficient storage unit and humidity / correction coefficient storage unit are updated as needed, so that the correction coefficient is determined in actual use. This makes it possible to replenish and supply a very precise recording solution.

  Further, the displacement amount of the negative pressure lever with respect to the predetermined recording liquid suction amount is a value when a predetermined amount of the recording liquid is sucked, so that the temperature or the pressure at the time of the recording liquid suction performed frequently in practical use is reduced. By calculating a coefficient with respect to environmental characteristic values such as humidity, it is possible to replenish and supply a very precise recording liquid with very simple control.

  Further, the displacement amount of the negative pressure lever with respect to the predetermined recording liquid suction amount is a value when a predetermined amount of air is sucked, so that an environmental characteristic value is obtained when air suction is performed to maintain negative pressure. By calculating the coefficient with respect to the above, it becomes possible to replenish and supply a very precise recording liquid with very simple control.

  Furthermore, the amount of displacement of the negative pressure lever corresponding to the recording liquid replenishment supply amount is defined based on the amount of displacement at the time of negative pressure formation. By calculating the coefficient for the characteristic value, it is possible to replenish and supply a very precise recording liquid with very simple control.

  An image forming apparatus as another invention is characterized by having the recording liquid replenishment supply amount control device. Therefore, it is possible to supply replenishment of recording liquid with high precision regardless of the environment, and stable image formation can be performed.

  According to the recording liquid replenishment supply amount control method of the present invention, when the recording liquid is replenished and supplied to the sub tank, the amount of displacement of the negative pressure lever with respect to the predetermined recording liquid suction amount is set to the environmental characteristic value in the vicinity of the sub tank. The recording liquid replenishment supply amount is controlled on the basis of the displacement amount of the negative pressure lever multiplied by the correction coefficient corresponding to. Therefore, it is possible to prevent problems such as recording liquid outflow from the recording head and deterioration of output image quality, and further, negative pressure in the recording head can be avoided without considering variations in the displacement of the negative pressure lever due to environmental changes in the sub tank. Can be maintained.

  FIG. 1 is a perspective view of an ink jet recording apparatus as an image forming apparatus of the present invention as viewed from the front. An ink jet recording apparatus 100 as an image forming apparatus according to the present invention shown in FIG. 1 includes an apparatus main body 101, a paper feed tray 102 for loading paper mounted on the apparatus main body 101, and a detachable attachment to the apparatus main body 101. And a paper discharge tray 103 for stocking the paper on which the image is recorded (formed). Further, a cartridge loading for loading an ink cartridge that protrudes from the front surface to the front side of the apparatus main body 101 and is lower than the upper surface is provided at one end of the front surface of the apparatus main body 101 (side of the paper supply / discharge tray section). The cartridge loading unit 104 is provided with an operation / display unit 105 such as operation buttons and a display.

  The cartridge loading unit 104 stores a plurality of recording liquids (inks) that are different color materials, such as black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. Ink cartridges 110k, 110c, 110m, and 110y (referred to as “ink cartridge 110” when the colors are not distinguished) are recording liquid cartridges serving as recording liquid storage units from the front side to the rear side of the apparatus main body 101. A front cover (cartridge cover) 106 that is opened when the ink cartridge 110 is attached or detached is provided on the front side of the cartridge loading unit 104 so as to be openable and closable. Further, the ink cartridges 110k, 110c, 110m, and 110y are configured to be loaded side by side in the horizontal direction in a vertically placed state.

  Further, the operation / display unit 105 has the remaining amounts of the ink cartridges 110k, 110c, 110m, and 110y for the respective colors at the arrangement positions corresponding to the installation positions (arrangement positions) of the ink cartridges 110k, 110c, 110m, and 110y for the respective colors. The remaining amount display sections 111k, 111c, 111m, and 111y for each color for displaying the near end and the end are arranged. Further, the operation / display unit 105 is also provided with a power button 112, a paper feed / print resume button 113, and a cancel button 114.

  Next, the mechanism part of the ink jet recording apparatus will be described with reference to FIGS. 2 is a side view showing the outline of the mechanism, and FIG. 3 is a plan view of the main part.

  In the mechanism of the ink jet recording apparatus, the carriage 133 is slidably held in the main scanning direction by a guide rod 131 and a stay 132 which are guide members horizontally mounted on the left and right side plates 121A and 121B constituting the frame 121. The main scanning motor that is not moved moves and scans in the direction indicated by the arrow (carriage main scanning direction) in FIG. 3 via the timing belt.

  As described above, the carriage 133 is provided with the recording head 134 including four droplet discharge heads that discharge ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk). A plurality of ink ejection openings are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward.

  As an inkjet head constituting the recording head 134, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change due to liquid film boiling using an electrothermal conversion element such as a heating resistor, and a metal phase change due to a temperature change. It is possible to use a shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, or the like provided as pressure generating means for generating a pressure for discharging a droplet.

  A driver IC is mounted on the recording head 134 and is connected to a control unit (not shown) via a harness (flexible print cable) 122. In addition, the carriage 133 is equipped with a sub tank 135 for each color for supplying ink of each color to the recording head 134. As described above, each color sub-tank 135 is supplementarily supplied with each color ink from each color ink cartridge 110 mounted in the cartridge loading unit 104 via each color ink supply tube 136. The cartridge loading 104 is provided with a supply pump unit 124 for feeding ink in the ink cartridge 110, and the ink supply tube 136 is locked to the rear plate 121C constituting the frame 121 in the middle of turning. It is held by the member 125.

  On the other hand, as a paper feeding unit for feeding the paper 142 stacked on the paper stacking unit (pressure plate) 141 of the paper feeding tray 102, a half-moon roller (feeding) that separates and feeds the paper 142 from the paper stacking unit 141 one by one. A separation pad 144 made of a material having a large friction coefficient is provided facing the paper roller 143 and the paper feed roller 143, and the separation pad 144 is urged toward the paper feed roller 143 side.

  In order to feed the sheet 142 fed from the sheet feeding unit to the lower side of the recording head 134, a guide member 145 for guiding the sheet 142, a counter roller 146, a transport guide member 147, and a tip pressure roller. And a holding belt 148 that is a conveying means for electrostatically attracting the fed paper 142 and conveying it at a position facing the recording head 134.

  The conveyor belt 151 is an endless belt, and is configured to wrap around the conveyor roller 152 and the tension roller 153 and circulate in the belt conveyance direction (sub-scanning direction). Further, a charging roller 156 that is a charging unit for charging the surface of the transport belt 151 is provided. The charging roller 156 is disposed so as to come into contact with the surface layer of the conveyor belt 151 and to rotate following the rotation of the conveyor belt 151. Further, a guide member 157 is disposed on the back side of the conveyance belt 151 so as to correspond to a printing area by the recording head 134.

  The transport belt 151 rotates in the belt transport direction of FIG. 3 when the transport roller 152 is rotationally driven through timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 142 recorded by the recording head 134, a separation claw 161 for separating the paper 142 from the transport belt 151, a paper discharge roller 162, and a paper discharge roller 163 are provided. A paper discharge tray 103 is provided below the paper discharge roller 162.

  A double-sided unit 171 is detachably attached to the back surface of the apparatus main body 101. The duplex unit 171 takes in the paper 142 returned by the reverse rotation of the transport belt 151, reverses it, and feeds it again between the counter roller 146 and the transport belt 151. The upper surface of the duplex unit 171 is a manual feed tray 172.

  Further, as shown in FIG. 3, a maintenance / recovery mechanism 181 including a recovery means for maintaining and recovering the nozzle state of the recording head 134 is arranged in the non-printing area on one side of the carriage 133 in the scanning direction. Yes.

  The maintenance / recovery mechanism 181 includes cap members (hereinafter referred to as “caps”) 182a to 182d (hereinafter referred to as “caps 182” when not distinguished) for capping each nozzle surface of the recording head 134, and nozzle surfaces. A wiper blade 183 that is a blade member for wiping the ink, and an empty discharge receiver 184 that receives liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the thickened recording liquid. ing. Here, the cap 182a is a suction and moisture retention cap, and the other caps 182b to 182d are moisture retention caps.

  Then, the waste liquid of the recording liquid generated by the maintenance / recovery operation by the maintenance / recovery mechanism 181, the ink discharged to the cap 182, the ink attached to the wiper blade 183 and removed by the wiper cleaner 185, and the idle ejection to the idle ejection receptacle 194 The discharged ink is discharged and stored in a waste liquid tank (not shown).

  Further, as shown in FIG. 3, in the non-printing area on the other side in the scanning direction of the carriage 133, idle discharge is performed to discharge liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An empty discharge receiver 188 for receiving the droplets is disposed, and the empty discharge receiver 188 is provided with an opening 189 along the nozzle row direction of the recording head 134.

  In the ink jet recording apparatus as the image forming apparatus of the present invention configured as described above, the sheet 142 is separated and fed one by one from the sheet feeding tray 102, and the sheet 142 fed substantially vertically upward is guided by the guide 145. Then, the paper is sandwiched between the conveyor belt 151 and the counter roller 146 and conveyed, and further, the front end is guided by the conveyance guide 137 and pressed against the conveyance belt 151 by the front end pressure roller 149 to change the conveyance direction by approximately 90 °. The

  At this time, a charging voltage pattern in which a positive output and a negative output are alternately repeated from the AC bias supply unit of the control unit, which will be described later, to the charging roller 156 alternately, that is, an alternating voltage is applied and the conveying belt 151 is alternating. That is, plus and minus are alternately charged in a band shape with a predetermined width in the sub-scanning direction which is the circumferential direction. When the sheet 142 is fed onto the conveying belt 151 that is alternately charged with plus and minus, the sheet 142 is attracted to the conveying belt 151, and the sheet 142 is conveyed in the sub-scanning direction by the circumferential movement of the conveying belt 151.

  Therefore, by driving the recording head 134 according to the image signal while moving the carriage 133 in the main scanning direction based on the main scanning position information by the linear encoder 137, the ink droplets are ejected onto the stopped paper 142. One line is recorded, and after the sheet 142 is conveyed by a predetermined amount, the next line is recorded. Upon receiving a recording end signal or a signal that the trailing edge of the sheet 142 has reached the recording area, the recording operation is terminated and the sheet 142 is discharged onto the discharge tray 103.

  During printing (recording) standby, the carriage 133 is moved to the maintenance / recovery mechanism 181 side, the recording head 134 is capped by the cap 182, and the nozzles are kept in a wet state, thereby preventing ejection failure due to ink drying. . Further, the recording liquid is sucked from the nozzle by a suction pump (not shown) with the recording head 134 capped by the cap 182 (referred to as “nozzle suction” or “head suction”), and the thickened recording liquid and bubbles are discharged. Perform recovery action. In addition, an idle ejection operation for ejecting ink not related to recording is performed before the start of recording or during recording. As a result, the stable ejection performance of the recording head 134 is maintained.

  FIG. 4 is a schematic diagram showing the configuration of the recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention. The recording liquid supply control mechanism 200 in the ink jet recording apparatus as the image forming apparatus of the present invention shown in the figure includes a supply pump 203 that supplies ink from the ink cartridge 201 that is a main tank to the sub tank 202, and ink in the sub tank 202. The position of a suction pump 204 that sucks, a negative pressure lever 206 that operates following a film 205 that operates according to the amount of ink stored in the sub tank 202, and a predetermined negative pressure lever 206 among the plurality of negative pressure levers 206 The position sensor 207 detects the amount of opening of the negative pressure lever 206 and the supply pump 203 or the suction pump 204 is operated according to the amount of opening of the negative pressure lever 206 detected by the position sensor 207, as will be described later. A control unit 208 for controlling the opening amount of the negative pressure lever 206, and suction A waste liquid tank 209 that stores ink sucked by the pump 204, an air release pin 210 that opens the negative pressure state in the sub tank 202 to the air state, and a sub tank 202 is provided in the vicinity of the sub tank 202 to detect the ambient temperature of the sub tank 202. A temperature sensor 211 and a humidity sensor 212 that is provided in the vicinity of the sub tank 202 and detects the ambient humidity of the sub tank 202 are provided.

  Further, as shown in FIG. 5, the control unit 208 in FIG. 4 includes an ink amount / negative pressure lever opening amount storage unit 208-1 that stores the relationship between the ink amount and the opening amount of the negative pressure lever, and a temperature. A temperature / correction coefficient storage unit 208-2 storing a correction coefficient for the ambient temperature of the sub tank 202 detected by the sensor 211, and a correction coefficient for the ambient humidity of the sub tank 202 detected by the humidity sensor 212 are stored. Temperature / correction coefficient storage for the opening amount of the negative pressure lever 206 with respect to a predetermined amount of ink read from the humidity / correction coefficient storage unit 208-3 and the ink amount / negative pressure lever opening amount storage unit 208-1. The negative pressure lever 206 is multiplied by the correction coefficient read from the section 208-2, the correction coefficient read from the humidity / correction coefficient storage section 208-3, or both correction coefficients. A negative pressure lever opening amount determining unit 208-4 for calculating and determining an opening amount, and an ink amount / negative pressure lever based on the opening amount of the negative pressure lever 206 determined by the negative pressure lever opening amount determining unit 208-4 And an ink replenishment amount control unit 208-5 for controlling the ink replenishment amount by reading the ink amount from the opening amount storage unit 208-1.

  Note that the position sensor 207 preferably detects the position of the negative pressure lever 206 provided in the sub-tank at both ends or one end among the plurality of sub-tanks installed in parallel in the main scanning direction. Further, the control unit 208 has a storage table that stores in advance position data of the negative pressure lever 206 determined from the relationship of the amount of movement of the negative pressure lever 206 with respect to the ink consumption in the sub tank 202 as shown in FIG. . Further, the control unit 208 updates the position data of the negative pressure lever 206 stored in the storage table by taking the average of the normal positions of the negative pressure lever 206, or the temperature and humidity detected by the temperature sensor 211. Control that can take into account variations in reading of the opening amount of the negative pressure lever 206 to some extent by sequentially taking and updating the negative pressure lever position average in accordance with changes in the ambient environment such as changes in humidity detected by the sensor 212. It can be performed.

  Next, the operation in the case of supplying a predetermined amount of ink of the recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention having such a configuration will be described below with reference to FIG. . First, when supplying a predetermined amount of ink, the closing amount of the negative pressure lever 206 is detected by the position sensor 207 in the ink jet recording apparatus of FIG. 4 (steps S101 and S102), and the negative pressure lever opening amount of FIG. 5 is determined. The temperature sensor 211 and / or the humidity sensor 212 adjusts the opening amount of the negative pressure lever 206 corresponding to a predetermined amount of ink read from the ink amount / negative pressure lever opening amount storage unit 208-1. The correction coefficient stored and read out in the temperature / correction coefficient storage unit 208-2 and / or the humidity / correction coefficient storage unit 208-3 of FIG. 5 corresponding to the detected environmental characteristic values such as temperature and humidity changes. To calculate and determine the opening amount of the negative pressure lever 206 (step S103). 5 supplies ink until the negative pressure lever 206 moves to the position of the negative pressure lever 206 corresponding to the determined opening amount of the negative pressure lever 206 (step S104). Step S105; NO). Thereafter, if the negative pressure lever 206 is detected at the determined position, the ink supply is stopped (step S105; YES, step S106), and a series of predetermined amount ink supply operations are terminated (step S107).

  In the recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention, even if there is a variation due to environmental fluctuations in the amount of movement of the negative pressure lever, for example, by introducing this control, Since the amount of movement of the negative pressure lever with respect to a specific predetermined amount of ink supplied for each sub tank can be defined, ink can be supplied very precisely.

  Next, another operation when a predetermined amount of ink is supplied by the recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention will be described with reference to FIG. First, when supplying a predetermined amount of ink, the closing amount of the negative pressure lever 206 is detected by the position sensor 207 in the inkjet recording apparatus of FIG. 4 (steps S201 and S202), and the negative pressure lever opening amount determination of FIG. The unit 208-4 detects the temperature detected by the temperature sensor 211 and / or the humidity sensor 212 based on the opening amount of the negative pressure lever 206 read from the ink amount / negative pressure lever opening amount storage unit 208-1 and updated as needed. 5 is multiplied by the correction coefficient stored and read out in the temperature / correction coefficient storage unit 208-2 and / or the humidity / correction coefficient storage unit 208-3 in FIG. The opening amount of the negative pressure lever 206 is calculated and determined (step S203). 5 supplies ink until the negative pressure lever 206 moves to the position of the negative pressure lever 206 corresponding to the determined opening amount of the negative pressure lever 206 (step S204). Step S205; NO). Thereafter, if the negative pressure lever 206 is detected at the determined position, the ink supply is stopped (step S205; YES, step S206), and a series of predetermined amount ink supply operations are terminated (step S207).

  In such a recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus according to the present invention, even if there is a variation in the amount of movement of the negative pressure lever, for example, by introducing this control, Since the amount of movement of the negative pressure lever with respect to a predetermined amount of ink supply can be defined, not only can the ink supply be performed very precisely, but also the negative pressure due to the environment in which the ink jet recording apparatus is placed from time to time Covers fluctuations in the lever and enables precise ink supply.

  Next, another operation when a predetermined amount of ink is supplied by the recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention will be described with reference to FIG. 8 showing the operation flow. First, when supplying a predetermined amount of ink, in the ink jet recording apparatus of FIG. 4, the closing amount of the negative pressure lever 206 is detected by the position sensor 207 (steps S301 and S302), and the negative pressure lever opening amount of FIG. 5 is determined. The unit 208-4 is read from the ink amount / negative pressure lever opening amount storage unit 208-1, and the temperature sensor 211 and / or humidity sensor 212 determines the opening amount of the negative pressure lever 206 when the ink is sucked by the suction pump 204. The correction coefficient stored and read out in the temperature / correction coefficient storage unit 208-2 and / or the humidity / correction coefficient storage unit 208-3 of FIG. 5 corresponding to the detected environmental characteristic values such as temperature and humidity changes. To calculate and determine the opening amount of the negative pressure lever 206 (step S303). 5 supplies ink until the negative pressure lever 206 moves to the position of the negative pressure lever 206 corresponding to the determined opening amount of the negative pressure lever 206 (step S304). Step S305; NO). Thereafter, if the negative pressure lever 206 is detected at the determined position, ink supply is stopped (step S305; YES, step S306), and a series of predetermined amount of ink supply operation is terminated (step S307).

  In such a recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus according to the present invention, even if there is a variation in the amount of movement of the negative pressure lever, for example, by introducing this control, Since the amount of movement of the negative pressure lever with respect to a predetermined amount of ink supply can be defined, not only can the ink supply be performed very precisely, but also the negative pressure due to the environment in which the ink jet recording apparatus is placed from time to time Covers fluctuations in the lever and enables precise ink supply.

  FIG. 9 is a schematic diagram showing the configuration of another recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention. In the figure, the same reference numerals as those in FIG. 4 denote the same components. The recording liquid supply control mechanism 200 in the ink jet recording apparatus as the image forming apparatus of the present invention shown in the figure includes a supply pump 203 that supplies ink from the ink cartridge 201 that is a main tank to the sub tank 202, and ink in the sub tank 202. The position of a suction pump 204 that sucks, a negative pressure lever 206 that operates following a film that operates according to the amount of ink stored in the sub tank 202, and a predetermined negative pressure lever 206 among the plurality of negative pressure levers 206. A position sensor 207 that detects and detects the opening amount of the negative pressure lever 206, and operates the supply pump 203, the suction pump 204, or the air suction pump 213 according to the opening amount of the negative pressure lever 206 detected by the position sensor 207. Control for performing control related to the opening amount of the negative pressure lever 206 as will be described later 208, a waste liquid tank 209 that stores ink sucked by the suction pump 204, an air release pin 210 that opens the negative pressure state in the subtank 202 to the atmospheric state, and a subtank 202 that is provided in the vicinity of the subtank 202. A temperature sensor 211 that detects the temperature and a humidity sensor 212 that is provided in the vicinity of the sub tank 202 and detects the ambient humidity of the sub tank 202 are provided.

  Next, the operation in the case of supplying a predetermined amount of ink of another recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention will be described with reference to FIG. 10 showing the operation flow. First, when supplying a predetermined amount of ink, the closing amount of the negative pressure lever 206 is detected by the position sensor 207 in the inkjet recording apparatus of FIG. 4 (steps S401 and S402), and the negative pressure lever opening amount of FIG. 5 is determined. The unit 208-4 is read from the ink amount / negative pressure lever opening amount storage unit 208-1, and the temperature sensor 211 and / or humidity sensor 212 is added to the opening amount of the negative pressure lever 206 when the air suction pump 213 sucks air. The temperature / correction coefficient storage unit 208-2 and / or the humidity / correction coefficient storage unit 208-3 in FIG. 5 corresponding to environmental characteristic values such as temperature and humidity changes detected by The opening amount of the negative pressure lever 206 is calculated and determined by multiplying the coefficient (step S403). 5 supplies ink until the negative pressure lever 206 moves to the position of the negative pressure lever 206 corresponding to the determined opening amount of the negative pressure lever 206 (step S404). Step S405; NO). Thereafter, if the negative pressure lever 206 is detected at the determined position, the ink supply is stopped (step S405; YES, step S406), and the series of predetermined amount ink supply operation is terminated (step S307).

  In such a recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus according to the present invention, even if there is a variation in the amount of movement of the negative pressure lever, for example, by introducing this control, Since the amount of movement of the negative pressure lever with respect to a predetermined amount of ink supply can be defined, not only can the ink supply be performed very precisely, but also the negative pressure due to the environment in which the ink jet recording apparatus is placed from time to time Covers fluctuations in the lever and enables precise ink supply.

  Next, another operation when a predetermined amount of ink is supplied by another recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention will be described with reference to FIG. 11 showing the operation flow. First, when supplying a predetermined amount of ink, the closing amount of the negative pressure lever 206 is detected by the position sensor 207 in the ink jet recording apparatus of FIG. 4 (steps S501 and S502), and the negative pressure lever opening amount of FIG. 5 is determined. The unit 208-4 is read from the ink amount / negative pressure lever opening amount storage unit 208-1, and is detected by the temperature sensor 211 and / or the humidity sensor 212 based on the opening amount of the negative pressure lever 206 when the negative pressure is formed. 5 is multiplied by the correction coefficient stored and read out in the temperature / correction coefficient storage unit 208-2 and / or the humidity / correction coefficient storage unit 208-3 in FIG. 5 corresponding to environmental characteristic values such as changes in temperature and humidity. Then, the opening amount of the negative pressure lever 206 is calculated and determined (step S503). 5 supplies ink until the negative pressure lever 206 moves to the position of the negative pressure lever 206 corresponding to the determined opening amount of the negative pressure lever 206 (step S504). Step S505; NO). Thereafter, if the negative pressure lever 206 is detected at the determined position, the ink supply is stopped (step S505; YES, step S506), and a series of predetermined amount ink supply operations are terminated (step S507).

  In such a recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus according to the present invention, even if there is a variation in the amount of movement of the negative pressure lever, for example, by introducing this control, Since the amount of movement of the negative pressure lever with respect to a predetermined amount of ink supply can be defined, not only can the ink supply be performed very precisely, but also the negative pressure due to the environment in which the ink jet recording apparatus is placed from time to time Covers fluctuations in the lever and enables precise ink supply.

  Next, another operation in the case of supplying a predetermined amount of ink of another recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention will be described below with reference to FIG. First, environmental characteristic values such as humidity and temperature are detected (step S601), and it is determined whether or not the detected environmental characteristic value exceeds a predetermined reference value (step S602). Note that the predetermined reference value is, for example, when the humidity or temperature changes greatly in an environment where the air-conditioning is used in an environment where the ink jet recording apparatus is installed. Humidity or temperature when the absolute position of the negative pressure lever 206 is detected by the position sensor 207 in filling, and humidity or temperature when the absolute position of the negative pressure lever 206 is detected by the position sensor 207 in the next open air filling The environmental characteristic value of temperature and humidity when the difference is 30% or more, for example. When the environmental characteristic value exceeds the predetermined reference value in step 602, the sub tank is opened to the atmosphere, and the absolute position of the negative pressure lever 206 is set as the initial position. The position of the negative pressure lever 206 is determined by the position sensor 207. After detecting again (step S602; YES, steps S603 and S604), a predetermined amount of ink is started to be supplied (step S605). When the environmental characteristic value does not exceed the predetermined reference value in step 602, a predetermined amount of ink is started without being filled with open air (step S602; NO, step S605). Thereafter, in the ink jet recording apparatus of FIG. 4, the closing amount of the negative pressure lever 206 is detected by the position sensor 207 (step S606), and the negative pressure lever opening amount determining unit 208-4 of FIG. The amount of opening of the negative pressure lever 206 that is read out from the amount storage unit 208-1 when the negative pressure is formed corresponds to an environmental characteristic value such as a change in temperature or humidity detected by the temperature sensor 211 and / or the humidity sensor 212. The opening amount of the negative pressure lever 206 is calculated and determined by multiplying the correction coefficient stored and read in the temperature / correction coefficient storage unit 208-2 and / or the humidity / correction coefficient storage unit 208-3 of FIG. (Step S607). 5 supplies ink until the negative pressure lever 206 moves to the position of the negative pressure lever 206 corresponding to the determined opening amount of the negative pressure lever 206 (step S608). Step S609; NO). Thereafter, if the negative pressure lever 206 is detected at the determined position, the ink supply is stopped (step S609; YES, step S610), and a series of predetermined amount ink supply operations are terminated (step S611).

  In each of the above embodiments, the correction operation is performed when a predetermined amount of ink is supplied. However, the present invention is not limited to this, and a similar correction operation may be performed when the head cleaning operation is performed. .

  Further, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and substitutions are possible as long as the description is within the scope of the claims.

1 is a perspective view of an ink jet recording apparatus as an image forming apparatus of the present invention as viewed from the front. It is a side view which shows the outline | summary of the mechanism part of an inkjet recording device. It is a principal part top view which shows the outline | summary of the mechanism part of an inkjet recording device. FIG. 2 is a schematic diagram illustrating a configuration of a recording liquid supply control mechanism in an ink jet recording apparatus as an image forming apparatus of the present invention. It is a block diagram which shows the structure of the control part of FIG. 4 is a flowchart showing an operation when a predetermined amount of ink is supplied by a recording liquid supply control mechanism in an ink jet recording apparatus as an image forming apparatus of the present invention. 6 is a flowchart showing another operation when a predetermined amount of ink is supplied by the recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention. 6 is a flowchart showing another operation when a predetermined amount of ink is supplied by the recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention. It is the schematic which shows the structure of another recording liquid supply control mechanism in the inkjet recording device as an image forming apparatus of this invention. 6 is a flowchart illustrating an operation when a predetermined amount of ink is supplied by another recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention. 6 is a flowchart showing another operation when a predetermined amount of ink is supplied by another recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention. 6 is a flowchart showing another operation when a predetermined amount of ink is supplied by another recording liquid supply control mechanism in the ink jet recording apparatus as the image forming apparatus of the present invention. It is a perspective view which shows the structure of the sub tank of an inkjet recording device.

Explanation of symbols

100; an ink jet recording apparatus,
200; recording liquid supply control mechanism; 201; ink cartridge;
202; sub tank, 203; supply pump, 204; suction pump,
205; Film; 206; Negative pressure lever; 207; Sensor;
208; control unit;
208-1; ink amount / negative pressure lever opening amount storage unit,
208-2; temperature / correction coefficient storage unit,
208-3; humidity / correction coefficient storage unit;
208-4; negative pressure lever opening amount determination unit,
208-5; ink replenishment amount control unit 209; waste liquid tank;
210; air release pin; 211; temperature sensor; 212; humidity sensor;
213; an air suction pump.

Claims (21)

The recording liquid is supplied from a nozzle to a recording head that discharges recording liquid droplets, and the recording liquid is replenished and supplied from a main tank on the apparatus main body side, and the amount of the recording liquid stored in the sub tank. The image forming apparatus includes one or a plurality of recording head units that are displaced in accordance with each other and have a negative pressure lever provided in the sub tank, and controls a replenishment supply amount of the recording liquid from the main tank to the sub tank. In the recording liquid replenishment supply amount control method,
When replenishing and supplying the recording liquid to the sub tank, the displacement amount of the negative pressure lever with respect to the predetermined recording liquid suction amount is multiplied by a correction coefficient corresponding to an environmental characteristic value in the vicinity of the sub tank. A recording liquid replenishment supply amount control method, wherein the recording liquid replenishment supply amount is controlled based on a displacement amount of a negative pressure lever. The recording liquid is supplied from a nozzle to a recording head that discharges recording liquid droplets, and the recording liquid is replenished and supplied from a main tank on the apparatus main body side, and the amount of the recording liquid stored in the sub tank. The image forming apparatus includes one or a plurality of recording head units that are displaced in accordance with each other and have a negative pressure lever provided in the sub tank, and controls a replenishment supply amount of the recording liquid from the main tank to the sub tank. In the recording liquid replenishment supply amount control method,
When the environmental characteristic value in the vicinity of the sub tank exceeds a predetermined reference value, the sub tank is opened to the atmosphere, the initial position of the negative pressure lever at that time is detected, and the recording liquid is replenished and supplied to the sub tank. The displacement amount of the negative pressure lever is obtained by multiplying the displacement amount of the negative pressure lever with respect to the predetermined suction amount of the recording liquid with respect to the initial position of the negative pressure lever by a correction coefficient corresponding to the environmental characteristic value. A recording liquid replenishment supply amount control method characterized in that the recording liquid replenishment supply amount is controlled based on the above.   3. The recording liquid replenishment supply amount control method according to claim 1, wherein the environmental characteristic value is one of temperature and humidity in the vicinity of the sub tank, or temperature and humidity.   3. The recording liquid replenishment supply amount control method according to claim 1, wherein the correction coefficient is updated as needed.   3. The recording liquid replenishment supply amount according to claim 1, wherein a displacement amount of the negative pressure lever with respect to a predetermined recording liquid suction amount is a value when a predetermined amount of the recording liquid is sucked. Control method.   3. The recording liquid replenishment supply amount control method according to claim 1, wherein a displacement amount of the negative pressure lever with respect to a predetermined recording liquid suction amount is a value when a predetermined amount of air is sucked. .   3. The recording liquid replenishment supply amount control according to claim 1, wherein a displacement amount of the negative pressure lever corresponding to the recording liquid replenishment supply amount is defined based on a displacement amount when the negative pressure is formed. Method.   3. The recording liquid replenishment supply amount control method according to claim 1, wherein the operation of replenishing and supplying the recording liquid to the sub tank is a head cleaning operation. The recording liquid is supplied from a nozzle to a recording head that discharges recording liquid droplets, and the recording liquid is replenished and supplied from a main tank on the apparatus main body side, and the amount of the recording liquid stored in the sub tank. The image forming apparatus includes one or a plurality of recording head units that are displaced in accordance with each other and have a negative pressure lever provided in the sub tank, and controls a replenishment supply amount of the recording liquid from the main tank to the sub tank. In the recording liquid replenishment supply amount control device,
A negative pressure lever displacement amount storage unit for storing a displacement amount of the negative pressure lever corresponding to a predetermined recording liquid amount for replenishing the sub tank with the recording liquid;
A temperature / correction coefficient storage unit that stores a correction coefficient of the displacement amount of the negative pressure lever with respect to the temperature near the sub tank;
A temperature detector for detecting the temperature around the sub-tank; and
A negative pressure lever position detector for detecting the amount of displacement of the negative pressure lever;
The correction read out from the temperature / correction coefficient storage unit based on the displacement of the negative pressure lever detected by the negative pressure lever position detection unit based on the temperature around the sub-tank detected by the temperature detection unit And a controller for controlling the recording liquid replenishment supply amount based on a displacement amount of the negative pressure lever multiplied by a coefficient.   When the temperature in the vicinity of the sub tank detected by the temperature detection unit exceeds a predetermined reference value, the sub tank is opened to the atmosphere, and the initial position of the negative pressure lever at that time is detected, and the control unit Multiplies the displacement amount of the negative pressure lever relative to the initial position of the negative pressure lever by the correction coefficient read from the temperature / correction coefficient storage unit, and replenishes the recording liquid based on the multiplied displacement amount of the negative pressure lever 10. The recording liquid replenishment supply amount control apparatus according to claim 9, wherein the supply amount is controlled. The recording liquid is supplied from a nozzle to a recording head that discharges recording liquid droplets, and the recording liquid is replenished and supplied from a main tank on the apparatus main body side, and the amount of the recording liquid stored in the sub tank. The image forming apparatus includes one or a plurality of recording head units that are displaced in accordance with each other and have a negative pressure lever provided in the sub tank, and controls a replenishment supply amount of the recording liquid from the main tank to the sub tank. In the recording liquid replenishment supply amount control device,
A negative pressure lever displacement amount storage unit for storing a displacement amount of the negative pressure lever corresponding to a predetermined recording liquid amount for replenishing the sub tank with the recording liquid;
A humidity / correction coefficient storage unit that stores a correction coefficient of a displacement amount of the negative pressure lever with respect to the humidity near the sub tank;
A humidity detector for detecting the humidity around the sub tank; and
A negative pressure lever position detector for detecting the amount of displacement of the negative pressure lever;
The correction read out from the humidity / correction coefficient storage unit based on the humidity in the vicinity of the sub-tank detected by the humidity detection unit in the displacement amount of the negative pressure lever detected by the negative pressure lever position detection unit And a controller for controlling the recording liquid replenishment supply amount based on a displacement amount of the negative pressure lever multiplied by a coefficient.   When the humidity around the sub-tank detected by the humidity detection unit exceeds a predetermined reference value, the sub-tank is opened to the atmosphere, and the initial position of the negative pressure lever at that time is detected, and the control unit Multiplies the displacement amount of the negative pressure lever with respect to the initial position of the negative pressure lever by the correction coefficient read from the humidity / correction coefficient storage unit, and replenishes the recording liquid based on the multiplied displacement amount of the negative pressure lever 12. The recording liquid replenishment supply amount control apparatus according to claim 11, wherein the supply amount is controlled. The recording liquid is supplied from a nozzle to a recording head that discharges recording liquid droplets, and the recording liquid is replenished and supplied from a main tank on the apparatus main body side, and the amount of the recording liquid stored in the sub tank. The image forming apparatus includes one or a plurality of recording head units that are displaced in accordance with each other and have a negative pressure lever provided in the sub tank, and controls a replenishment supply amount of the recording liquid from the main tank to the sub tank. In the recording liquid replenishment supply amount control device,
A negative pressure lever displacement amount storage unit for storing a displacement amount of the negative pressure lever corresponding to a predetermined recording liquid amount for replenishing the sub tank with the recording liquid;
A temperature / correction coefficient storage unit that stores a correction coefficient of the displacement amount of the negative pressure lever with respect to the temperature near the sub tank;
A humidity / correction coefficient storage unit that stores a correction coefficient of a displacement amount of the negative pressure lever with respect to the humidity near the sub tank;
A temperature detector for detecting the temperature around the sub-tank; and
A humidity detector for detecting the humidity around the sub tank; and
A negative pressure lever position detector for detecting the amount of displacement of the negative pressure lever;
The amount of displacement of the negative pressure lever detected by the negative pressure lever position detection unit is calculated based on the temperature around the sub tank detected by the temperature detection unit or the vicinity of the sub tank detected by the humidity detection unit. Multiplying the correction coefficient read from the temperature / correction coefficient storage unit or the humidity / correction coefficient storage unit, or the temperature / correction coefficient storage unit and the humidity / correction coefficient storage unit based on humidity or temperature and humidity And a controller for controlling the replenishment supply amount of the recording liquid based on the displacement amount of the negative pressure lever.   When the temperature around the sub-tank detected by the temperature detection unit exceeds a predetermined reference value, or when the humidity around the sub-tank detected by the humidity detection unit exceeds a predetermined reference value When the sub-tank is opened to the atmosphere, the initial position of the negative pressure lever at that time is detected, and the control unit stores the temperature / correction coefficient in the displacement amount of the negative pressure lever with respect to the initial position of the negative pressure lever. Or the humidity / correction coefficient storage unit, or the temperature / correction coefficient storage unit and the correction coefficient read from the humidity / correction coefficient storage unit, and the recording based on the displacement amount of the negative pressure lever multiplied 14. The recording liquid replenishment supply amount control apparatus according to claim 13, wherein the liquid replenishment supply amount is controlled.   15. The recording liquid replenishment supply amount control device according to claim 9, wherein the correction coefficient stored in the temperature / correction coefficient storage unit is updated as needed. .   The recording liquid replenishment supply amount control apparatus according to claim 11, wherein the correction coefficient stored in the humidity / correction coefficient storage unit is updated as needed.   15. The displacement amount of the negative pressure lever with respect to a predetermined amount of the recording liquid sucked is a value when a predetermined amount of the recording liquid is sucked. Recording liquid replenishment supply amount control device.   15. The recording liquid replenishment supply according to claim 9, wherein a displacement amount of the negative pressure lever with respect to a predetermined recording liquid suction amount is a value when a predetermined amount of air is sucked. Quantity control device.   15. The recording liquid replenishment according to claim 9, wherein a displacement amount of the negative pressure lever corresponding to the recording liquid replenishment supply amount is defined based on a displacement amount when the negative pressure is formed. Supply amount control device.   15. The recording liquid replenishment / supply amount control apparatus according to claim 9, wherein the operation of replenishing and supplying the recording liquid to the sub tank is a head cleaning operation. The recording liquid is supplied from a nozzle to a recording head that discharges recording liquid droplets, and the recording liquid is replenished and supplied from a main tank on the apparatus main body side, and the amount of the recording liquid stored in the sub tank. In the image forming apparatus comprising one or a plurality of recording head units that are displaced in response to each other and have a negative pressure lever provided in the sub tank.
21. An image forming apparatus comprising the recording liquid replenishment supply amount control device according to claim 9.

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