JP2010105192A - Ink jet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the supply speed of ink, which has been limited by a supply control valve that opens/closes only by a change in the internal pressure of a recording head in an ink jet recorder adopting a pressure supply system. <P>SOLUTION: The ink jet recorder is provided with a means in which a supply control valve opened and closed by variation of the internal pressure of the recording head can be opened and closed also from exterior as required. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs recording by ejecting ink and the like, and in particular, the ink supply speed of an ink jet recording apparatus having an ink supply system that supplies high-speed and large-capacity ink is increased. It is about.

  Conventionally, an ink jet recording apparatus often uses an ink jet recording head mounted on a carriage that reciprocates across a recording medium such as recording paper. As the recording head moves across the recording medium, the control electronics activate the ejection portion of the recording head to eject ink drops from the ejection nozzles to form an image or character on the recording medium. Ink is supplied to the recording head by an ink supply container (hereinafter referred to as ink tank).

  Some recording apparatuses store a replaceable ink tank in a part of the main body of the recording apparatus, and supply ink to the recording head via a flexible and hollow fluid conduit connected to the ink tank. There is also a recording apparatus in which a recording head above the recording medium in the gravity direction discharges ink droplets downward. In that case, the inside of the recording head is maintained at a slight negative pressure, and the ink in the ejection nozzles should form a meniscus at the boundary with the atmosphere.

  As a conventional example of such an ink supply system, for example, there is one using a water head difference between an air opening portion provided in the vicinity of an ink tank and an ink discharge portion of a recording head (for example, see Patent Document 1). This water head difference method has an advantage that an ink supply system can be manufactured at a low cost, but has a problem that the layout of the recording head and the ink tank is limited and the ink supply speed during printing is slow.

  On the other hand, the manufacturing cost increases because a complicated negative pressure generation mechanism is required, but a pressure supply method has been put to practical use as an ink supply system that overcomes the problems of the water head difference method. For example, in Patent Document 2, a spring bag is provided in the liquid chamber of the recording head, and the supply valve is opened and closed in conjunction with the behavior of the spring bag, thereby supplying ink into the liquid chamber and reducing the negative pressure in the liquid chamber. Retention is realized. Although a specific method is not disclosed, since the supplied ink is pressurized, the ink is immediately supplied to the liquid chamber when the supply valve is opened. Further, the ink tank may be located anywhere as long as a predetermined pressure can be realized, and a layout-free design can be performed.

  However, in the negative pressure generating mechanism described in Patent Document 2 described above, even if a small amount of ink is supplied even if the negative pressure in the liquid chamber increases and the supply valve opens, the pressure in the spring bag and the negative pressure in the liquid chamber are balanced. Since the supply valve is closed, it is not suitable for supplying a large amount of ink in a short time. An example of the need to supply a large amount of ink in a short time is ink filling (initial filling) when a new recording head is mounted. The applicant of Patent Document 2 has put the ink jet recording apparatus into practical use without performing initial filling. However, if the initial filling is performed, the configuration as in Patent Document 2 takes time.

  As means for supplying a large amount of ink in a short time, there is a means as disclosed in Patent Document 3, for example. According to this, a valve that can be arbitrarily opened and closed is provided in the middle of the ink supply flow path, and suction is performed from the ink discharge portion of the recording head by the suction means while the valve is closed, and the negative pressure in the recording head is sufficiently reduced. Open the valve in a raised state. At this time, since the pressure difference between the inside of the recording head and the inside of the ink tank is very large, ink is supplied to the recording head at a relatively high speed.

However, the valve disclosed in Patent Document 3 cannot be opened and closed in accordance with fluctuations in the internal pressure of the liquid chamber and cannot be used as a pressure supply type ink supply system.
JP 2002-307709 (Section 25, FIG. 2) Special table 2001-514985 (paragraph 32, Fig. 1) Japanese Patent Laid-Open No. 2001-71536 (Section 8 and FIG. 2)

  In view of the above problems, the present invention provides an ink jet recording apparatus that can supply a large amount of ink in a short time while being a pressure supply system.

  In order to achieve the above object, a first invention relating to the present application is a first invention in which an ink tank that is detachably fixed to an ink jet recording apparatus body and supplies ink, and a recording head mounted on a carriage has a discharge mechanism In an ink jet recording apparatus having a liquid chamber and a second liquid chamber having negative pressure generating means and supplying ink from the ink tank to the second liquid chamber by pressurization, the ink tank is provided for supplying ink from the ink tank. The valve provided at the location where the fluid conduit is connected to the second liquid chamber opens and closes according to changes in the internal pressure of the second liquid chamber, and arbitrarily opens and closes the valve by an external action. It is characterized by having means to do.

  A second invention related to the present application is characterized in that the valve moves in conjunction with a diaphragm that moves in accordance with a change in internal pressure of the second liquid chamber.

  The third invention related to the present application is characterized in that the operation of the diaphragm can be temporarily stopped by an external action.

  In addition, a fourth invention related to the present application is characterized in that the operation from the outside is controlled by measuring a time during which the action from the outside is acting.

  In addition, a fifth invention related to the present application is characterized in that the operation from the outside controls the operation of the diaphragm by an internal pressure measuring means provided in the second liquid chamber.

  The effect of the present invention is to supply a large amount of ink in a short time in a pressure supply type ink supply system in which the ink supply speed during printing is relatively fast and the layout of the ink tank can be freely designed. It makes it possible.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  The best mode for carrying out the present invention includes an ink tank that is detachably fixed to an ink jet recording apparatus main body and supplies ink, and a recording head mounted on a carriage includes a first liquid chamber having a discharge mechanism and a negative pressure. An ink jet recording apparatus having a second liquid chamber having a generating unit and supplying ink from an ink tank to the second liquid chamber by pressurization, wherein a fluid conduit provided for supplying ink from the ink tank A valve provided at a location connected to the second liquid chamber opens and closes according to a change in internal pressure of the second liquid chamber, and has means for arbitrarily opening and closing the valve by an external action. That's it.

  Further, the valve moves in conjunction with a diaphragm that moves according to a change in the internal pressure of the second liquid chamber.

  The diaphragm can be temporarily stopped by an external action.

  Further, the action from the outside is to control the operation of the diaphragm by measuring the time during which the action is exerted.

  The external action is to control the operation of the diaphragm by an internal pressure measuring means provided in the second liquid chamber.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The present invention is not limited to these embodiments, and these may be further combined, and all changes and modifications included in the concept of the present invention described in the claims may be made. Of course, it can be applied to other technologies to which it belongs.

  FIG. 3 shows an ink jet recording apparatus 500 in this embodiment. The ink jet recording apparatus 500 includes a recording head 100 connected to a replaceable ink tank 200 via a fluid conduit 250. The recording head 100 receives ink from the fluid conduit 250 and allows the ink to be selectively ejected onto a recording medium (not shown) under the control of the recording device control board 450.

  The ink tank 200 includes a bag body 202 formed of a flexible member, a rubber plug 201 that seals the ink outlet, and a case 205 that seals the bag body 202. One end of the fluid conduit 250 allows the ink to be led out to the fluid conduit 250 by inserting an ink needle 203, which is a hollow tube having a sharp tip, into the rubber stopper 201. Simultaneously with the insertion of the ink needle 203 into the rubber stopper, the pressure pump 210 is connected to the case. The pressurizing pump 210 pressurizes the periphery of the bag body 202 by sending pressurized air to the case 205, and sends the ink contained in the bag body to the fluid conduit and the recording head.

  The recording head 100 is formed in an airtight integrated manner by connecting a first liquid chamber below the gravity direction having a discharge nozzle 105 downward and a second liquid chamber 110 having a negative pressure generating means and above the gravity direction.

  In the second liquid chamber 110, a supply port 113 for receiving ink from the fluid conduit 250 and a supply filter 102 connected to the first liquid chamber 101 located below the second liquid chamber in the direction of gravity are formed as ink flow paths. Is done.

  The negative pressure generating means is a diaphragm 111 that is a flexible member and a diaphragm spring 112 that deforms the diaphragm 111. The diaphragm 111 is formed such that one side faces the second liquid chamber and the other side is exposed to the atmosphere, and the second liquid chamber 110 is deformed by the diaphragm spring 112 that deforms the diaphragm 111 toward the atmosphere where the volume increases. A slight negative pressure in the liquid chamber 110 is realized. The fine negative pressure generated in the second liquid chamber also generates substantially the same fine negative pressure in the first liquid chamber 101 connected in an airtight manner, and a recording medium (not shown) below the recording head 100 is generated. A good meniscus is formed on the nozzle 105 that opens downward toward the surface.

  The supply control means is a supply control valve 160 that is interlocked with the negative pressure generating means. The supply port 113 is intermittently opened and closed by a supply control valve 160 formed of an elastic member. The supply control valve 160 that operates integrally through the diaphragm 111 and the arm 161 receives the spring force applied by the diaphragm spring 112 and closes the supply port 113. The negative pressure in the recording head varies due to ink ejection. The supply control valve 160 is opened at a pressure exceeding a predetermined slight negative pressure, and ink flows from the supply port 113. The pressure in the recording head increases and becomes a predetermined slight negative pressure again. In the continuous recording operation, ink is supplied to the recording head by an intermittent opening / closing operation of the supply control valve.

  The first liquid chamber 101 and the second liquid chamber 110 form a circulation path via the pump chamber 120.

  The first liquid chamber 101 forms a one-way flow path having a supply filter 102 on the ink inlet side and a discharge filter 103 on the ink outlet side at both ends in the longitudinal direction along the plurality of nozzle rows 105. A flow path having an inclined surface 104 is formed above the nozzle 105, the lower side of the inclined surface is the supply filter 102, and the upper side of the heavy inclined surface is the discharge filter 103.

  The pump means for removing the air reservoir in the first liquid chamber is a diaphragm pump 121. The bubble removal pump chamber 120 is a small chamber that forms a circulation path between the first liquid chamber 101 and the second liquid chamber 110, and has an on-off valve A130, an on-off valve B131, and a bubble that open and close the connection flow path in one direction, respectively. The vacuum pump chamber is formed by a diaphragm pump 121 formed of a flexible member that changes the volume.

  The on-off valve A130 is a one-way valve that opens in the bubble removal pump chamber and the on-off valve B131 opens in the second liquid chamber.

  A means for removing air from the second liquid chamber 110 is a discharge port 114. An umbrella valve 180 is provided further downstream of the discharge port 114 via an air vent channel 181 to isolate the first and second liquid chambers in the recording head from the atmosphere. The discharge port 114 is opened and closed intermittently by the full tank control valve 150. The operation of the full tank control valve 150 is performed by the buoyancy of the float 140. When the second liquid chamber 110 is filled with ink and the float 140 is lifted, the full control valve closes the discharge port 114 around the rotation shaft 145 as the rotation center. When the ink is reduced from the second liquid chamber by the recording operation, the full control valve 150 is opened. An air vent 182 opens to the atmosphere downstream of the umbrella valve 180.

  The recovery system 300 improves problems such as nozzle clogging in the recording head 100. The recovery system 300 includes a suction negative pressure generator 330 and a nozzle cap 310, an air vent cap 320, a flow path 311 and a flow path 321 that connect the cap and the suction negative pressure generator, and an on-off valve 312 and an on-off valve 322, respectively. The negative pressure generator is composed of a tube pump (not shown), a drive motor, and a drive control board.

  Next, the ink flow and the operation of each part in the recording operation will be described.

(Initial filling operation)
FIG. 1 is a drawing that best represents an embodiment of the present invention. The arm 401 that is linked to the recovery system or driven independently of the recovery system is connected to the diaphragm 111, and can move the diaphragm 111 up and down freely. Using this arm 401, the initial filling time is shortened by the following procedure.

  There is no ink in the fluid conduit 250, the first liquid chamber 101, and the second liquid chamber 110 during the initial filling. The ink tank 200 is connected to the ink needle 203. The periphery of the bag body is pressurized with a pressure pump, and the ink is supplied.

  The air vent cap 320 is engaged with the air vent port 182, and the nozzle cap 310 is engaged with the recording head face surface (nozzle same surface) with the nozzle 105. The on-off valve 312 is closed and the on-off valve 322 is opened. The arm 401 acts to pull the diaphragm 111 upward. The negative pressure generated by the negative pressure generating unit 330 generates a negative pressure higher than the negative pressure generated by the diaphragm 111 and the diaphragm spring 112 that make the second liquid chamber have a slight negative pressure by continuously operating the tube pump. The high generated negative pressure causes the air vent cap portion to be in a negative pressure state and the umbrella valve 180 connected to the flow path to be in an open state. The float 140 is in a lowered state in the second liquid chamber without ink, and the full control valve 150 opens the discharge port 114. Opening the umbrella valve 180 causes the air vent channel 181 to be in a negative pressure state, and the second liquid chamber eventually has a negative pressure higher than the slight negative pressure. At this time, since the diaphragm 111 is pulled upward by the arm 401, the supply control valve 160 is not opened unless the negative pressure is higher than when the diaphragm 111 is not pulled. Then, if the action of the arm 401 on the diaphragm 111 is eliminated at a predetermined timing, the supply control valve 160 is opened sufficiently large and long. At this time, the ink in the ink tank 200 is guided into the second liquid chamber at a high speed because the negative pressure in the fluid conduit 250 is also sufficiently high. The ink guided to the second liquid chamber flows into the first liquid chamber located below the gravitational direction. As the amount of ink in the second liquid chamber increases, the float 140 rises and the full control valve 150 closes the outlet 114.

  The timing at which the action of the arm 401 on the diaphragm 111 is excluded is preferably when a predetermined time has elapsed since the negative pressure generating unit 330 was operated. Alternatively, the pressure in the second liquid chamber 110 may be measured using the pressure gauge 170 and may be reached when a predetermined negative pressure is reached.

(Mixing of air)
The recording head 100 is expected to discharge ink semipermanently. Even if all of the ink in the ink tank 200 is discharged from the discharge nozzle 105 of the recording head 100 via the fluid conduit 250, it is possible to perform continuous operation by replacing the ink tank 200. When the ink tank 200 is replaced, the ink needle 203 that has been disconnected from the rubber plug 201 is exposed to the atmosphere, so that an air pocket is held inside the hollow tube. When the supply is resumed, the air reservoir is sent to the recording head side through the fluid conduit 250. The fluid conduit 250 is formed of a flexible material such as polyethylene resin and a material having low gas permeability, and enables the recording head 100 to move on the recording medium. Since this cannot be prevented, air mixed in the fluid conduit 250 is sent to the recording head 100 after resuming the recording operation for long-term storage of the recording apparatus 500.

  In the recording operation by ink ejection, when air is trapped from the nozzle 105 or dissolved air in the ink is generated as bubbles in the first liquid chamber 101, the bubbles pass through the inclined surface 104 and below the discharge filter 103. Accumulate as a pool.

(Air venting operation)
The operation of removing air from the first liquid chamber is performed by circulation of the first liquid chamber 101, the second liquid chamber 110, and the pump chamber 120. The nozzle cap 310 is closed so that the meniscus of the nozzle 105 is not broken when the circulation is performed.

  The volume change of the pump chamber 120 is realized by the deformation of the diaphragm pump 121. A part of the diaphragm pump 121 is deformed up and down by the reciprocating motion of the arm 400 driven from the recovery system, thereby causing a pressure change as the volume of the pump chamber 120 changes. As the arm 400 descends, the pressure in the pump chamber increases, the on-off valve A130 is closed, and the on-off valve B131 is opened. Next, the pressure in the pump chamber 120 is lowered by the raising operation of the arm 400, the on-off valve B131 is closed, and the on-off valve A130 is opened. Since the pressure in the pump chamber 120 is lower than the slight negative pressure, the ink below the discharge filter 103 moves to the pump chamber 120. At this time, if there is an air reservoir below the discharge filter 103, the air moves to the pump chamber 120 together with the moving ink. When the pressure of the pump chamber 120 is increased by lowering the arm 400 again, the air that has moved from the first liquid chamber 101 moves to the second liquid chamber by opening the on-off valve B131. Thus, the air that has moved together with the ink accumulates above the second liquid chamber by circulating the ink in the order of the first liquid chamber → the pump chamber → the second liquid chamber → the first liquid chamber. .

  In the second liquid chamber, the liquid level of the ink is lowered due to the movement of air, and the full control valve 150 is opened as the float 140 is lowered. If the air vent cap 320 is joined to the air vent port 182 and a negative pressure is generated by driving the recovery system 300, it is clear that the air in the second liquid chamber is discharged through the umbrella valve 180.

  Air that has permeated through the fluid conduit 250 due to long-term storage and air in the hollow tube mixed by replacing the ink tank is accumulated above the second liquid chamber by resuming the recording operation, and air venting is realized by opening the full control valve. The

  FIG. 2 is a drawing that best represents an embodiment of the present invention. The arm 401 that is linked to the recovery system or driven independently of the recovery system is connected to the diaphragm 111, and can move the diaphragm 111 up and down freely. Using this arm 401, the initial filling time is shortened by the following procedure.

  There is no ink in the fluid conduit 250, the first liquid chamber 101, and the second liquid chamber 110 during the initial filling. The ink tank 200 is connected to the ink needle 203. The periphery of the bag body is pressurized with a pressure pump, and the ink is supplied.

  The air vent cap 320 is engaged with the air vent port 182, and the nozzle cap 310 is engaged with the recording head face surface (nozzle same surface) with the nozzle 105. The on-off valve 312 is closed and the on-off valve 322 is opened. The arm 401 acts to push down the diaphragm 111 downward. The negative pressure generated by the negative pressure generating unit 330 generates a negative pressure higher than the negative pressure generated by the diaphragm 111 and the diaphragm spring 112 that make the second liquid chamber have a slight negative pressure by continuously operating the tube pump. The high generated negative pressure causes the air vent cap portion to be in a negative pressure state and the umbrella valve 180 connected to the flow path to be in an open state. The float 140 is in a lowered state in the second liquid chamber without ink, and the full control valve 150 opens the discharge port 114. Opening the umbrella valve 180 causes the air vent channel 181 to be in a negative pressure state, and the second liquid chamber eventually has a negative pressure higher than the slight negative pressure. At this time, since the diaphragm 111 is pushed downward by the arm 401, the supply control valve 160 is always open. Therefore, since the ink is originally supplied in a pressurized state and the second liquid chamber has a high negative pressure, the ink in the ink tank 200 is guided into the second liquid chamber at a high speed. The ink guided to the second liquid chamber flows into the first liquid chamber located below the gravitational direction. As the amount of ink in the second liquid chamber increases, the float 140 rises and the full control valve 150 closes the outlet 114.

  The timing at which the action of the arm 401 on the diaphragm 111 is excluded is preferably when a predetermined time has elapsed since the negative pressure generating unit 330 was operated. Alternatively, the pressure in the second liquid chamber 110 may be measured using the pressure gauge 170 and may be reached when a predetermined negative pressure is reached.

In an ink jet recording head and an ink jet recording apparatus provided with a liquid chamber having a valve that opens and closes according to a change in the internal pressure of the liquid chamber and can be freely opened and closed by an external action. It is a figure explaining initial ink filling. In an ink jet recording head and an ink jet recording apparatus having a liquid chamber with a valve that opens and closes according to a change in the internal pressure of the liquid chamber and can be freely opened and closed by an external action. It is a figure explaining initial ink filling. Ink-jet recording head and ink-jet recording provided with a valve in the liquid chamber that opens and closes according to changes in the internal pressure of the liquid chamber and can be freely opened and closed by an external action It is a figure explaining an apparatus.

Explanation of symbols

100 recording head
101 First chamber
102 Supply filter
103 Discharge filter
104 Inclined surface
105 Discharge nozzle
110 Second liquid chamber
111 Diaphragm
112 Diaphragm spring
113 Supply port
114 outlet
120 Pump room
121 Diaphragm pump
130 On-off valve A
131 On-off valve B
140 Float
145 rotation axis
150 Full control valve
160 Supply control valve
161 arm
170 Pressure gauge
180 Umbrella valve
181 Air vent channel
182 Air vent
200 Ink tank
201 Rubber stopper
202 bags
203 Ink needle
205 cases
210 Pressure pump
250 Fluid conduit
300 recovery
310 Nozzle cap
311 flow path
312 On-off valve
320 Air vent cap
321 flow path
322 On-off valve
330 Suction negative pressure generator
400 Arm 1
401 Arm 2
450 Recording device control board
500 Inkjet recording device

Claims (5)

An ink tank that is detachably fixed to the ink jet recording apparatus main body and supplies ink, and a recording head mounted on the carriage has a first liquid chamber having a discharge mechanism and a second liquid chamber having a negative pressure generating means, In an ink jet recording apparatus that supplies ink from an ink tank to the second liquid chamber by pressurization,
A valve provided at a location where a fluid conduit provided for supplying ink from the ink tank is connected to the second liquid chamber opens and closes in response to a change in internal pressure of the second liquid chamber; An ink jet recording apparatus comprising means for arbitrarily opening and closing the valve by an external action.   2. The ink jet recording apparatus according to claim 1, wherein the valve moves in conjunction with a diaphragm that moves in accordance with a change in internal pressure of the second liquid chamber.   The inkjet recording apparatus according to claim 1, wherein the diaphragm can be temporarily stopped by an external action.   4. The ink jet recording apparatus according to claim 1, wherein the action from the outside controls the operation of the diaphragm by measuring a time during which the action is exerted.   4. The ink jet recording apparatus according to claim 1, wherein the action from the outside controls an operation of the diaphragm by an internal pressure measuring unit provided in the second liquid chamber. 5. .

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