JP5845637B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus that forms an image by ejecting ink onto a recording medium.

  An ink jet recording apparatus ejects ink from a head toward a recording medium to form an image on the recording medium. In this ink jet recording apparatus, a part of the ink ejected from the head becomes ink mist drifting in the apparatus without adhering to the recording medium. This ink mist adheres to various devices in the apparatus and contaminates these devices. Thus, various techniques for collecting ink mist floating in the apparatus have been proposed.

  For example, in the technique described in Patent Document 1 below, ink mist is sucked through a duct opening by a fan, and the ink mist is absorbed and collected by a filter provided in the duct.

JP 2009-220499 A

However, in the technique described in Patent Document 1, the ink attached to the upstream portion of the filter in the fan blowing direction is dried by the blowing of the fan, and the viscosity of the ink increases. Since the ink with increased viscosity is less likely to be absorbed by the filter, the filter may be clogged due to the ink being deposited in the upstream portion of the filter in the fan blowing direction. Thus, when clogging due to ink accumulation occurs in the upstream portion of the filter in the fan blowing direction, fan blowing cannot be performed, and thus ink cannot be absorbed in the downstream portion of the filter in the fan blowing direction. Therefore, the filter reaches the end of its life earlier than the amount of ink that can be absorbed by the entire filter and needs to be replaced.

  Accordingly, an object of the present invention is to provide an ink jet recording apparatus capable of improving the life of a filter.

In order to solve the above problems, an ink jet recording apparatus of the present invention includes an ink discharge head that discharges ink for forming an image on a recording medium, a duct having an introduction port and a discharge port, and the ink. Blowing means that introduces air in the discharge space into the duct from the introduction port and blows air toward the discharge port, a filter that is provided in the duct and is made of an ink absorber, and And heating means for heating the upstream portion in the air blowing direction of the filter.

According to the above structure, the viscosity of the ink adhered to the airflow direction upstream portion of the filter is, becomes lower by heating by the heating means, the filter is likely to absorb ink. Alternatively, it is possible to promote the movement of ink from the upstream portion in the blowing direction to the downstream portion in the blowing direction in the filter. As a result, the entire filter can absorb ink efficiently, and the life of the filter can be improved.

  In the ink jet recording apparatus of the present invention, the heating unit may perform the heating when the blowing unit performs the blowing. According to said structure, since the movement of the ink from the ventilation direction upstream part in a filter to the ventilation direction downstream part can be further accelerated | stimulated by ventilation of the air by a ventilation means, an ink is absorbed efficiently with the whole filter. be able to.

  In the ink jet recording apparatus of the present invention, the heating unit may heat the entire filter. According to said structure, since the viscosity of the ink adhering to the whole filter can be reduced, ink can be absorbed more efficiently by the whole filter.

  In the ink jet recording apparatus of the present invention, the heating unit may be a heater.

  In the ink jet recording apparatus of the present invention, the ink jet recording apparatus further includes a drying unit for heating and drying the recording medium to which the ink ejected by the ink ejection head is attached, and the heating unit is the heating drying unit of the drying unit. The heating may be performed by the exhaust heat generated by. According to said structure, since a filter is heated using the exhaust heat of a drying means, it is not necessary to provide the heat source for heating a filter newly.

Further, in the ink jet recording apparatus according to a first aspect of the present invention, the filter includes a heat absorption material, said heating means, Ru humidifier der to humidify the air in the ejection space. According to said structure, the air humidified by the heating means is supplied to a filter by a ventilation means. Thereby, since the filter itself becomes a heat source, the viscosity of the ink adhered to the filter can be efficiently reduced.

In the ink jet recording apparatus according to the second aspect of the present invention, the filter is detachably attached to the duct, and the heating means has a predetermined operating time of the air blowing means after the filter is attached. When the time is reached, the heating is performed. According to the above configuration, when it has become much amount of ink adhering to the air blowing direction upstream portion of the filter, the filter is heated. Accordingly, the viscosity of the ink adhered to the airflow direction upstream portion of the filter is lowered, it is possible to reliably suppress the clogging of the filter due to the viscosity increase of the ink.

  In the inkjet recording apparatus of the present invention, the heating unit may perform the heating when the ink is not ejected from the ink ejection head. According to the above configuration, the maximum drive power of the entire ink jet recording apparatus can be reduced, so that the power supply system can be made compact.

In the ink jet recording apparatus according to the third aspect of the present invention, the air blowing unit includes a fan and a motor that rotates the fan, and the heating unit detects a current value of the motor. has a detection unit, wherein the heating means, when the current value is out of the predetermined range, it intends row the heating. According to the above configuration, the filter is heated when the current value of the motor deviates from a predetermined range due to the degree of clogging of the filter increasing and the flow path resistance of the filter increasing. As a result, the viscosity of the ink adhering to the filter is lowered, so that clogging of the filter due to an increase in the viscosity of the ink can be reliably suppressed.

  The life of the filter that absorbs ink mist can be improved.

1 is a schematic side view showing an internal structure of an ink jet printer according to a first embodiment of an ink jet recording apparatus of the present invention. It is a top view which shows the flow path unit and actuator unit of an inkjet head, and head holder which are included in the printer of FIG. FIG. 3 is an enlarged view showing a region III surrounded by an alternate long and short dash line in FIG. 2. It is the schematic which shows the head holder, the humidification mechanism, and duct which are included in the printer of FIG. FIG. 5 is a partial cross-sectional view showing a region VI surrounded by an alternate long and short dash line in FIG. 4. (A) is a graph which shows the relationship between the viscosity of ink, and temperature, (b) is a figure explaining the positional relationship of an air exhaust duct, a filter, and a heater seen from the ventilation direction of the fan. It is a figure explaining the modification of a heater, (a) is a fragmentary sectional side view of the heater periphery which concerns on a 1st modification, (b) is the air discharge seen from the ventilation direction of the fan which concerns on a 1st modification. It is a figure explaining the positional relationship of a duct, a filter, and a heater. Moreover, (c) is a partial sectional side view of the periphery of the heater according to the second modification, and (d) is a positional relationship between the air discharge duct, the filter, and the heater according to the second modification, as viewed from the fan blowing direction. FIG. It is a graph which shows the relationship between the electric current value of a fan motor, and the air blowing volume in a duct. It is a block diagram which shows schematic structure of the control apparatus shown in FIG. It is an operation | movement flowchart of the control apparatus shown in FIG. It is explanatory drawing explaining the heating means of 2nd Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
First, an overall configuration of an inkjet printer 101 according to a first embodiment of the inkjet recording apparatus of the present invention will be described with reference to FIG.

  The printer 101 has a rectangular parallelepiped housing 101a. A paper discharge unit 15 is provided on the top plate of the housing 101a. The internal space of the housing 101a can be divided into spaces A, B, and C in order from the top. In the spaces A and B, a conveyance path of the paper P from the paper supply unit 101b to the paper discharge unit 15 is formed. In the space A, image formation on the paper P and conveyance of the paper P to the paper discharge unit 15 are performed. In the space B, the paper P is fed to the conveyance path. From the space C, the ink liquid is supplied to the ink ejection head 1 in the space A.

  In the space A, an ink discharge head 1 (hereinafter referred to as the head 1), a transport mechanism 16 that transports the paper P in the transport direction (a direction from the left to the right in FIG. 1), and a guide unit that guides the paper P. A duct 60 and a fan (see FIG. 4) used for collecting ink mist, a drying mechanism 31 for heating and drying the paper P after image formation, a humidifying mechanism 80 (see FIG. 4) used for humidifying maintenance, A display 94 (see FIG. 9) that displays various information, a control device 100, and the like are arranged.

  The head 1 is a line type head having a substantially rectangular parallelepiped shape that is long in the main scanning direction, and is supported by the housing 101 a via a head holder 35. The lower surface of the head 1 is an ejection surface 1a in which a plurality of ejection ports 108 (see FIG. 3) for ejecting black ink droplets are opened. Here, the sub-scanning direction is a direction parallel to the transport direction of the transport mechanism 16, and the main scanning direction is a direction orthogonal to the sub-scanning direction and along the horizontal plane.

  The head holder 35 supports the head 1 so that a predetermined gap suitable for recording is formed between the ejection surface 1 a and the conveyance belt 8. The peripheral configuration of the head 1 and the head holder 35 will be described in detail later.

  The transport mechanism 16 includes two belt rollers 6 and 7, a transport belt 8, a tension roller 10, a platen 18, a nip roller 4, and a peeling plate 5. The conveyor belt 8 is an endless belt wound between both rollers 6 and 7, and tension is applied by a tension roller 10. The platen 18 is disposed to face the head 1 and supports the upper loop of the conveyor belt 8 from the inside. The belt roller 7 is a drive roller that rotates in the clockwise direction in FIG. The belt roller 6 is a driven roller that rotates when the conveyor belt 8 travels. A weakly adhesive silicon layer is formed on the conveyance surface 8 a of the conveyance belt 8. The nip roller 4 presses the conveyed paper P against the transport surface 8a. The pressed sheet P is held on the conveyor belt 8 by the silicon layer. The peeling plate 5 peels the paper P on the transport belt 8 from the transport belt 8.

  The guide unit has an upstream guide unit and a downstream guide unit that are arranged with the transport mechanism 16 interposed therebetween in the transport direction. The upstream guide unit includes guides 13 a and 13 b and a feed roller pair 14, and connects the paper feed unit 101 b and the transport mechanism 16. The downstream guide unit includes guides 29 a, 29 b, 29 c and three feed roller pairs 28, and connects the transport mechanism 16 and the paper discharge unit 15.

  The drying mechanism 31 is provided as a constituent member of the guide 29b downstream of the head 1 in the transport direction. The drying mechanism 31 includes a drying heater 31a and a heating surface 31b. The heating surface 31b is a part of the inner surface of the guide 29b. When the drying heater 31a is energized under the control of the control device 100, the heating surface 31b heats the paper P after image formation to a predetermined temperature or more and dries it.

  In the space B, the paper feeding unit 101b is arranged. The paper feed unit 101 b includes a paper feed tray 11 and a paper feed roller 12. Among these, the paper feed tray 11 is detachable from the housing 101a. The paper feed tray 11 is a box that opens upward, and stores a plurality of papers P. The paper feed roller 12 sends out the uppermost paper P in the paper feed tray 11.

  In the space C, the tank unit 101c is detachably attached to the housing 101a. The ink tank 17 is detachably attached to the tank unit 101c. The ink tank 17 stores black ink liquid, and is connected to the head 1 via a tube (not shown) and a pump (not shown).

  Next, the control device 100 will be described. The control device 100 controls each part of the printer 101 and controls the operation of the entire printer 101. The control device 100 performs an image forming operation based on image data (recording command) received from an external device (such as a PC connected to the printer 101). Specifically, the control device 100 controls the paper feed unit 101b, the transport mechanism 16, each pair of feed rollers 14, 28, and the like based on the recording command. The paper P sent out from the paper feed tray 11 is sent to the transport mechanism 16 by the upstream guide unit. When the paper P on the transport surface 8a passes just below the head 1, the head 1 is controlled by the control device 100, and ink droplets are ejected from the ejection surface 1a onto the paper P. As a result, a desired monochrome image is formed on the paper P. The ink ejection operation is performed based on a detection signal from a paper sensor (not shown) that detects the leading edge of the paper P. The paper P on which the image is formed is peeled off from the transport belt 8 by the peeling plate 5 and then guided by the downstream guide portion and is also heat-dried by the drying mechanism 31 to open the opening 22 above the housing 101a. To the paper discharge unit 15.

  Further, the control device 100 performs an air blowing operation for collecting ink mist generated during the image forming operation, a filter heating operation for heating the filter 20 described later, and a humidifying maintenance for recovering and maintaining the ink ejection characteristics of the head 1. Controls the operation. The air blowing operation, the filter heating operation, and the humidification maintenance operation will be described in detail later.

  Next, the head 1 will be described in detail with reference to FIGS. In FIG. 3, for convenience of explanation, the pressure chamber 110, the aperture 112, and the discharge port 108 that are to be drawn with broken lines below the actuator unit 21 are drawn with solid lines.

  As shown in FIGS. 2 and 3, the head 1 has a flow path unit 9 and eight actuator units 21 fixed to the upper surface 9 a of the flow path unit 9. In the upper surface 9a of the flow path unit 9, 18 ink supply ports 105b to which ink is supplied are opened. Inside the flow path unit 9, a manifold flow path 105 communicating with the ink supply port 105b, a plurality of sub-manifold flow paths 105a included in the manifold flow path 105, and the sub-manifold flow paths 105a branch from the pressure. A plurality of individual ink flow paths are formed through the chamber 110 to the ejection port 108 that opens to the ejection surface 1a. A plurality of discharge ports 108 are arranged in a matrix on the discharge surface 1a.

The actuator unit 21 includes a plurality of unimorph actuators corresponding to the pressure chambers 110 and has a function of selectively applying ejection energy to the ink in the pressure chambers 110. In addition to the flow path unit 9, the head 1 includes a reservoir unit that stores ink supplied to the flow path unit 9, a flexible printed circuit (FPC) that supplies a drive signal to the actuator unit 21, and an FPC. A laminated body in which circuit boards and the like for controlling the driver IC mounted on the board are laminated.

  The ink flow in the flow path unit 9 will be described. The ink supplied from the reservoir unit to the ink supply port 105 b is distributed to the sub manifold channel 105 a of the manifold channel 105. Ink in the sub-manifold channel 105 a flows into each individual ink channel via the aperture 112 and reaches the ejection port 108 via the pressure chamber 110. In this state, when the actuator unit 21 is driven and discharge energy is applied to the ink in the pressure chamber 110, an ink droplet is discharged from the discharge port 108.

  Next, the peripheral structure of the head holder 35 will be described with reference to FIGS. 2, 4, and 5.

  As shown in FIG. 4, an air introduction duct 61, a pair of joints 81, and an annular cap 40 that creates a closed space are attached to the head holder 35.

  The air introduction duct 61 is disposed over the entire side surface of the head 1 and constitutes one end of the duct 60 (air blowing passage). As shown in FIG. 2, the air introduction duct 61 is a rectangular frame in a plan view and accommodates the discharge surface 1 a on the inner side. As shown in FIG. 5, the air introduction duct 61 includes a main body portion 61x and an upper portion 61y from the discharge surface 1a side. A hollow space 61w is formed in the main body 61x along the vertical direction from the lower end to the upper end of the main body 61x. The lower end of the main body 61x (the lower end of the air introduction duct 61) is farther from the transport surface 8a than the discharge surface 1a, and is an introduction port 61a that surrounds the entire circumference of the discharge surface 1a in plan view. On the upper surface of the upper portion 61y, a plurality of cylindrical connection portions 62 are provided along the contour of the head 1 at regular intervals. The cylindrical space 62w inside the connecting portion 62 also penetrates the upper portion 61y and communicates with the hollow space 61w. The connection part 62 has a notch in the outer periphery of its upper end surface, and has a tapered shape. Thereby, the connection of the end of the below-mentioned branch duct 63 to the connection part 62 becomes easy.

  As shown in FIG. 4, the pair of joints 81 constitute one end and the other end of the circulation flow path of the humidifying mechanism 80, respectively, and sandwich the air introduction duct 61 and the discharge surface 1a with respect to the main scanning direction. Has been placed. In the humidifying maintenance operation, air is recovered from an opening (air inlet) 81a on the lower surface of one of the joints 81 (the left side in FIG. 4) and the other (the right side in FIG. 4). Humidified air is supplied from the opening (air discharge port) 81b.

  As shown in FIG. 5, the joint 81 has a substantially cylindrical shape, and includes a bottom portion 81x and a tip portion 81y extending from the bottom portion 81x. A cylindrical hollow space 81z along the vertical direction passes through from the bottom 81x to the tip 81y. The bottom portion 81x has a flange portion that extends outward (in a direction away from the ejection surface 1a) in plan view. Further, the lower end of the bottom portion 81 x is at the same height level as the lower end of the main body portion 61 x of the air introduction duct 61. The tip 81y has a notch on the outer periphery of its upper end surface, and has a tapered shape. Thereby, the connection of the end of the below-mentioned tube 86 to the front-end | tip part 81y becomes easy.

  The cap 40 surrounds the discharge space S1 facing the discharge surface 1a with the transport surface 8a. The cap 40 is an annular member that surrounds the discharge surface 1 a, the air introduction duct 61, and the pair of joints 81 in a plan view, and includes an elastic body 41 and a movable body 42. The elastic body 41 is made of an elastic material such as rubber, and the movable body 42 is made of a metal rigid material.

  The elastic body 41 is formed in an annular shape surrounding the discharge surface 1a, the air introduction duct 61, and the pair of joints 81 in a plan view, and as shown in FIG. 5, a fixed portion 41c, a connection portion 41d, a base portion 41x, and a protrusion It is comprised from the part 41a. The fixing portion 41c has a T shape in cross section, and the upper end portion is fixed to the head holder 35 with an adhesive or the like. Further, the fixing portion 41 c is sandwiched between the head holder 35 and the flange portion (bottom portion 81 x) of the joint 81. The connecting portion 41d connects the lower ends of the fixed portion 41c and the base portion 41x, and extends outward (in a direction away from the ejection surface 1a in plan view) while curving downward. The curvature of the connecting portion 41d enables relative movement of the base portion 41x with respect to the fixing portion 41c. The base 41x has a recess 41b formed on the upper surface, and is fitted to the lower end of the conductor 42. A projecting portion 41a projecting downward is formed on the lower surface. The protrusion 41a has an inverted triangular shape in cross section.

  Similar to the elastic body 41, the movable body 42 is formed in an annular shape surrounding the discharge surface 1 a, the air introduction duct 61, and the pair of joints 81 in plan view. The movable body 42 is movable in the vertical direction with respect to the head holder 35 while being supported by the head holder 35 via the elastic body 41. Specifically, the movable body 42 is connected to a plurality of gears 43 and moves up and down through the gears 43 under the control of the control device 100 as the lifting motor 44 (see FIG. 9) is driven. At this time, the base 41x and the protrusion 41a move up and down together with the movable body 42. Thereby, the relative position of the perpendicular direction of the cap front-end | tip 40a of the protrusion part 41a and the discharge surface 1a changes.

  The protruding portion 41a has a contact position (see FIG. 5) where the cap tip 40a contacts the transport surface 8a of the transport belt 8 by raising and lowering the movable body 42, and a separation position where the cap tip 40a is separated from the transport surface 8a (see FIG. 4)). As shown in FIG. 5, when the protrusion 41a is in the contact position, the discharge space S1 is in a sealed state isolated from the external space S2. Further, as shown in FIG. 4, when the protruding portion 41a is at the separation position, the discharge space S1 is in an unsealed state opened to the external space S2.

  Next, the duct 60 will be described with reference to FIG. As shown in FIG. 4, the duct 60 includes an air introduction duct 61, a plurality of branch ducts 63, and an air discharge duct 64. The plurality of branch ducts 63 connect the air discharge duct 64 and the connection portions 62 of the air introduction duct 61 so as to communicate with each other, branch off from the air discharge duct 64 and extend to the corresponding connection portions 62. doing. A discharge port 64a that is one end of the air discharge duct 64 faces the external space S2, and air is discharged from the discharge port 64a to the external space S2 when air is blown. Thereby, the various apparatuses arrange | positioned in external space S2 are air-cooled. A filter 20 and a fan 95 are provided in the air discharge duct 64.

  The fan 95 rotates as the fan motor 96 is driven under the control of the control device 100. The fan motor 96 is provided with an ammeter (current value detector) 98 for detecting the current value (input current) of the fan motor 96 (see FIG. 9 respectively). The current value of the fan motor 96 varies depending on the magnitude of the flow path resistance of the filter 20.

  The filter 20 is an ink absorber made of a porous material or the like, and is supported by a filter support portion (not shown) fixed in the air discharge duct 64. The filter 20 is detachable from the filter support part. That is, the filter 20 is detachably attached to the air discharge duct 64. An attachment / detachment sensor 99 (see FIG. 9) for detecting attachment / detachment of the filter 20 with respect to the air discharge duct 64 is provided in the filter support portion. The control device 100 determines whether or not the filter 20 is attached to the air discharge duct 64 based on the presence or absence of a signal from the attachment / detachment sensor 99.

  In this configuration, during the air blowing operation, the fan 95 is driven by the fan motor 96, and the air in the discharge space S1 flows along the black arrow in FIG. That is, the air in the discharge space S1 is introduced into the air introduction duct 61 from the introduction port 61a, passes through the air introduction duct 61, the branch duct 63, and the air discharge duct 64 in order, and is discharged to the external space S2 through the discharge port 64a. Is done. At this time, ink mist contained in the air introduced into the duct 60 is absorbed by the filter 20 and collected. Thereby, the air from which the ink mist has been removed is discharged from the discharge port 64a.

  Here, the ink adhering to the upstream portion 20a in the air blowing direction of the fan 95 in the filter 20 is dried by the air blowing by the fan 95, and the viscosity of the absorbed ink increases. Since the ink whose viscosity has increased in this manner is difficult to be absorbed by the filter 20, the filter 20 may be clogged when the ink accumulates at the upstream portion 20 a in the blowing direction of the filter 20. Therefore, in the present embodiment, the upstream portion 20a in the blowing direction of the filter 20 is heated and attached to the filter 20 by using the property of the ink whose viscosity decreases as the temperature rises (see FIG. 6A). By reducing the viscosity of the ink, clogging of the filter 20 is suppressed.

  Specifically, in this embodiment, as shown in FIG. 6B, a cylindrical shape surrounding the air discharge duct 64 when viewed from the blowing direction of the fan 95 (the direction from the left to the right in FIG. 4). The heater 91 is provided on the outer wall of the air discharge duct 64. As shown in FIG. 4, the position of the upstream end of the heater 91 in the axial direction coincides with the upstream end 20b of the filter 20 in the air blowing direction of the fan 95, and the position of the downstream end is upstream of the air blowing direction of the filter 20. It exists in the position between the end 20b and the downstream end 20d in the air blowing direction. A temperature sensor 97 for measuring the temperature of the filter 20 is embedded in the filter 20 (not shown in FIG. 4). Under the control of the control device 100, the heater 91 is controlled by the filter 20 via the air discharge duct 64 and the filter support so that the temperature of the filter 20 becomes a predetermined temperature or higher based on a signal from the temperature sensor 97. The air flow direction upstream portion 20a is heated. Thereby, since the viscosity of the ink adhering to the upstream part 20a of the air flow direction of the filter 20 becomes low, it becomes easy for the filter 20 to absorb the ink. And the movement of the ink by the capillary phenomenon from the ventilation direction upstream part 20a in the filter 20 to the ventilation direction downstream part 20c can be accelerated | stimulated. As a result, the entire filter 20 can absorb ink efficiently, and the life of the filter 20 can be improved. Moreover, since the fluidity of the ink on the filter surface is improved when the viscosity of the ink is lowered, the ink adhered in the filter 20 by air blowing is moved from the blowing direction upstream portion 20a toward the blowing direction downstream portion 20c. Can do. As a result, the ink can be absorbed more efficiently by the entire filter 20.

  A first modification of the heater for heating the filter 20 is shown in FIGS. In the heater 92 according to the first modification, as shown in FIGS. 7A and 7B, the heater 92 changes from the blowing direction upstream end 20 b of the filter 20 to the blowing direction downstream end 20 d with respect to the blowing direction of the fan 95. It is provided over. Thereby, since the heater 92 can heat the filter 20 whole, the viscosity of the ink adhering to the filter 20 whole can be reduced, As a result, the ink can be absorbed more efficiently by the filter 20 whole. it can.

  Moreover, the 2nd modification of a heater is shown to (c), (d) of FIG. The heater 93 according to the second modified example is provided in the air discharge duct 64 and includes heater groups 93 a and 93 b including a plurality of thin rod-like heaters extending in a direction orthogonal to the air blowing direction of the fan 95. The heater groups 93 a and 93 b are provided separately from each other in the blowing direction of the fan 95. Further, the heater groups 93a and 93b are arranged so as not to overlap each other when viewed from the air blowing direction of the fan 95. By comprising in this way, the filter 20 can be heated efficiently, without inhibiting the flow of the air which passes the inside of the filter 20 as much as possible.

  Although the configuration of the heater that heats the filter 20 has been described above, the configuration is not particularly limited as long as the upstream portion 20a in the air blowing direction of the filter 20 can be heated. For example, a heater that radiates radiant heat may be disposed at a position upstream of the filter 20 in the air exhaust duct 64 in the air blowing direction, and the filter 20 may be heated by the heater.

  Next, the humidifying mechanism 80 will be described with reference to FIG. The humidification mechanism 80 includes a pair of joints 81, a water tank 85, tubes 86, 87, 88 and a humidification pump 89.

  The water tank 85 stores water in the lower space, and stores humidified air humidified by the water in the lower space in the upper space. One end of the tube 86 is fitted to the tip 81 y of one joint 81 (left side in FIG. 4) attached to the head holder 35, and the other end is connected to the humidification pump 89. That is, the tube 86 connects the hollow space 81z of one joint 81 and the humidification pump 89 so that they can communicate with each other. The tube 87 connects the humidification pump 89 and the lower space of the water tank 85 so that they can communicate with each other. One end of the tube 88 is connected to the upper space of the water tank 85, and the other end is fitted to the tip 81 y of the other (right side in FIG. 4) joint 81 attached to the head holder 35. That is, the tube 88 connects the hollow space 81z of the other joint 81 and the upper space of the water tank 85 so as to communicate with each other. The humidification pump 89 generates air flow from the discharge space S1 to the water tank 85 and air flow from the water tank 85 to the discharge space S1 under the control of the control device 100. The tube 87 is provided with a check valve (not shown) so that the water in the water tank 85 does not flow into the humidification pump 89, so that air flows only in the direction of the white broken line arrow in FIG. It has become.

  In this configuration, when the humidification maintenance operation is executed, the humidification pump 89 is driven under the control of the control device 100. Thereby, the air of discharge space S1 is supplied to the water tank 85 via the air inflow port 81a and the tubes 86 and 87, and is humidified. Then, the air humidified by the water tank 85 is discharged from the air discharge port 81b to the discharge space S1 via the tube 88. When the amount of water stored in the water tank 85 is reduced, water is supplied from a supply tank (not shown).

  Next, the control device 100 will be described with reference to FIG. The control device 100 includes a CPU (Central Processing Unit), a program executed by the CPU and a ROM (Read Only Memory) that stores data used in these programs in a rewritable manner, and temporarily stores data when the program is executed. RAM (Random Access Memory). Each functional unit constituting the control device 100 is constructed by cooperation of these hardware and software in the ROM. As illustrated in FIG. 9, the control device 100 includes a conveyance control unit 151, an image data storage unit 152, a head control unit 153, a blower control unit 154, a heating control unit 155, a drying control unit 156, and maintenance. And a control unit 157.

  The transport control unit 151 controls the paper feed unit 101b, the feed roller pairs 14 and 28, and the transport mechanism 16 so that the paper P is transported from the paper feed unit 101b to the paper discharge unit 15. The image data storage unit 152 stores image data related to image formation supplied from an external device.

  The head control unit 153 drives the actuator unit 21 of the head 1 based on the image data stored in the image data storage unit 152 to eject ink droplets having a desired volume from the ejection port 108 at a desired timing.

  The air blowing control unit 154 drives the fan motor 96 to rotate the fan 95, thereby introducing the air in the discharge space S1 into the duct 60 from the introduction port 61a and blowing air toward the discharge port 64a. I do. In the present embodiment, the air blowing means is configured by the air blowing control unit 154, the fan 95, and the fan motor 96.

  The heating control unit 155 controls the driving of the heater 91 to perform a filter heating operation, and includes a heating data storage unit 160 and a heating determination unit 161. The heating data storage unit 160 stores the operating time of the fan 95 (the operating time of the air blowing operation) after the attachment / detachment sensor 99 detects the attachment of the filter 20 in the air discharge duct 64. Further, the heating data storage unit 160 stores a normal current value range of the fan motor 96 in which the flow path resistance of the filter 20 is a predetermined value or less.

  The heating determination unit 161 is based on the operating time of the fan 95 stored in the heating data storage unit 160, or the normal current value range of the fan motor 96 and the current value of the fan motor 96 detected by the ammeter 98. It is determined whether or not the filter 20 is heated. Specifically, the heating determination unit 161 heats the filter 20 when the operating time of the fan 95 reaches a predetermined time or when the current value of the fan motor 96 is out of the normal current value range. Judge that. Here, the current value of the fan motor 96 will be described with reference to FIG. FIG. 8 is a graph showing the relationship between the amount of air blown into the duct 60 by the fan 95 and the current value of the fan motor 96. The appropriate drive range of the fan 95 is set together with the fan motor selection at the time of duct design from the viewpoint of ink mist collection performance, quietness, and stable drive. Corresponding to the appropriate drive range of the fan 95, the normal current value range (I1 to I2) of the fan motor 96 is determined. When the filter 20 is clogged due to ink mist accumulation, the amount of air blown in the duct 60 decreases, and the current value of the fan motor 96 increases. When the current value of the fan motor exceeds I2, it is determined that the current value of the fan motor 96 is out of the normal current value range. Conversely, when the current value of the fan motor 96 is less than I1, it is determined that an abnormality such as disconnection has occurred. Note that the characteristics of FIG. 8 vary depending on the characteristics of the fan motor, and there are fan motors that have a characteristic that the current value of the fan motor decreases as the amount of air blown in the duct becomes smaller than the appropriate drive range of the fan. Furthermore, if the current value of the fan motor 96 is out of the normal current value range even when the filter 20 is heated for a predetermined time, the heating determination unit 161 determines that the filter 20 has reached the end of its life. On the other hand, an image that prompts replacement of the filter 20 is displayed on the display 94. In the present embodiment, the heating control unit 155, the heater 91, and the ammeter 98 constitute a heating unit.

  The drying control unit 156 controls the drying heater 31a so that the ink attached to the paper P after image formation is dried.

  During the humidifying maintenance operation, the maintenance control unit 157 drives the lifting motor 44 to bring the cap tip 40a into contact with the transport surface 8a, thereby bringing the discharge space S1 into a sealed state. Further, the maintenance control unit 157 controls the driving of the humidification pump 89 so that the air in the discharge space S1 in the sealed state is humidified.

  Next, the operation of the printer 101 will be described below with reference to FIG. First, as shown in FIG. 10, the printer 101 receives a recording command from an external device (A1). When the recording command is received, the air blowing control unit 154 starts an air blowing operation (A2). Specifically, the air blow control unit 154 introduces the fan motor 96 so that the air in the discharge space S1 is introduced into the duct 60 from the introduction port 61a by the rotation of the fan 95 and is blown toward the discharge port 64a. Start drive control. Thereby, the airflow which goes to the inlet 61a arises in discharge space S1.

  Next, the heating determination unit 161 determines whether the filter 20 needs to be heated (A3). That is, when the operating time of the fan 95 reaches a predetermined time, or when the current value of the fan motor 96 is out of the normal current value range, it is determined that heating of the filter 20 is necessary. Determines that heating of the filter 20 is unnecessary.

  If the heating determination unit 161 determines that heating of the filter 20 is not necessary (A3: NO), the process proceeds to step A6. On the other hand, when it is determined that the filter 20 needs to be heated (A3: YES), the heating control unit 155 drives the heater 91 so that the filter 20 is heated and performs the filter heating operation for a predetermined time (A4). ). Thereby, since the viscosity of the ink adhering to the upstream portion 20a in the air blowing direction of the filter 20 is lowered, the filter 20 can easily absorb the ink. Further, it is possible to promote the movement of ink from the upstream portion 20a in the blowing direction to the downstream portion 20c in the blowing direction in the filter 20. Furthermore, since the air blowing operation is performed when this filter heating operation is being performed, in addition to the capillary phenomenon of the filter 20 itself, the ink adhered in the filter 20 by the air blowing is upstream of the blowing direction. It can be moved from the portion 20a toward the downstream portion 20c in the blowing direction. As a result, the ink can be absorbed more efficiently by the entire filter 20.

  After step A4, the heating determination unit 161 determines whether or not the current value of the fan motor 96 is out of the normal current value range (A5). If it is determined that the current value of the fan motor 96 is not out of the normal current value range (A5: NO), the process proceeds to step A6. On the other hand, when it is determined that the current value of the fan motor 96 deviates from the normal current value (A5: YES), the heating control unit 155 determines that the filter 20 has reached the end of its life, A screen prompting replacement is displayed on the display 94 (A15), and this processing is terminated.

  In step A6, the control device 100 starts an image forming operation. Specifically, the transport control unit 151 controls the paper feed unit 101b, the feed roller pairs 14, 28, and the transport mechanism 16 so that the paper P is transported from the paper feed unit 101b to the paper discharge unit 15. The head control unit 153 drives the actuator unit 21 of the head 1 based on the image data stored in the image data storage unit 152 to eject a desired volume of ink droplets from the ejection port 108 at a desired timing. . Then, the drying control unit 156 controls the drying mechanism 31 so that the paper P to which the ink is attached is heated and dried. The ink ejection timing is determined based on the detection signal from the paper sensor as described above.

  During this image forming operation, a part of the ink ejected from the head 1 becomes an ink mist without adhering to the paper P. However, since the air blowing operation is performed by the air blowing control unit 154, the ink mist is introduced. It is introduced into the duct 60 through the port 61a and is collected by the filter 20. Thereby, it is possible to prevent the ink mist from adhering to the printer 101 and being contaminated. Further, since the control device 100 starts the air blowing operation before performing the image forming operation, the air flow toward the inlet 61a generated by the air blowing operation is in a stable state during the image forming operation. Yes. As a result, ink mist generated during the image forming operation can be efficiently introduced into the duct 60.

  Further, during the image forming operation, the heating determination unit 161 determines whether or not the filter 20 needs to be heated (A7). If it is determined that heating of the filter 20 is unnecessary (A7: NO), the process proceeds to step A9. On the other hand, when it is determined that heating of the filter 20 is necessary (A7: YES), the heating control unit 155 starts the filter heating operation by driving the heater 91 so that the filter 20 is heated (A8). Thereby, since the viscosity of the ink adhering to the upstream portion 20a in the air blowing direction of the filter 20 is lowered, the filter 20 can easily absorb the ink. Further, it is possible to promote the movement of ink from the upstream portion 20a in the blowing direction to the downstream portion 20c in the blowing direction in the filter 20. When the process of step A8 is completed, the process proceeds to step A9. The filter heating operation is performed until the current value of the fan motor 96 falls within the normal current value range.

  In step A9, the control device 100 determines whether or not the image forming operation has been completed. If it is determined that the image forming operation has not ended (A9: NO), the process returns to step A7. On the other hand, if it is determined that the image forming operation has been completed (A9: YES), the air blowing control unit 154 controls the fan motor 96 to stop the rotation of the fan 95, and the air blowing operation is terminated (A10). . In the process of step A10, even when the process of step A9 is performed, if the filter heating operation is performed by the heating control unit 155, the filter heating operation is also terminated.

  Next, the maintenance control unit 157 drives the lifting motor 44 to bring the cap tip 40a of the cap 40 into contact with the transport surface 8a (A11). As a result, the discharge space S1 is sealed from the external space S2. Thereafter, the maintenance control unit 157 drives the humidification pump 89 so that air circulation occurs between the discharge space S1 and the water tank 85 (A12). Specifically, when the humidification pump 89 is driven, the air in the discharge space S1 reaches the humidification pump 89 through the air inlet 81a and the space in the tube 86, and further passes through the space in the tube 87. The water tank 85 is reached. The air is supplied to the lower space of the water tank 85 (that is, below the water surface). The air humidified by the water in the water tank 85 is discharged from the upper space of the water tank 85, passes through the space in the tube 88, and is supplied from the air discharge port 81b into the discharge space S1. By supplying the humidified air to the discharge space S1 in this way, ink evaporation near the discharge port 108 is suppressed, and the discharge port 108 can be prevented from being clogged. Further, even if the ink in the vicinity of the ejection port 108 is thickened, the thickening of the ink is eliminated (recovered) by supplying moisture from the humidified air.

  After step A12, control device 100 determines whether or not a new recording command has been received (A13). If it is determined that the recording command has not been received (A13: NO), the process returns to step A12. On the other hand, if it is determined that the recording command has been received (A13: YES), the maintenance control unit 157 drives the lifting motor 44 to separate the cap tip 40a of the cap 40 from the transport surface 8a (A14). As a result, the discharge space S1 is in an unsealed state opened to the external space S2. Thereafter, the process returns to step A2. The operation of the printer 101 has been described above.

  As described above, according to the present embodiment, the viscosity of the ink attached to the upstream portion 20a in the air blowing direction of the filter 20 is lowered by the heating by the heater 91, so that the filter 20 can easily absorb the ink. Or the movement of the ink from the ventilation direction upstream part 20a in the filter 20 to the ventilation direction downstream part 20c can be promoted. As a result, the entire filter 20 can absorb ink efficiently, and the life of the filter 20 can be improved.

  Further, according to the present embodiment, since the heating control unit 155 performs the filter heating operation when performing the air blowing operation by the blowing control unit 154, in addition to the capillary phenomenon of the filter 20 itself, By blowing air, the ink adhered in the filter 20 can be moved from the upstream portion 20a in the blowing direction toward the downstream portion 20c in the blowing direction. As a result, the ink can be absorbed more efficiently by the entire filter 20.

  Further, according to the present embodiment, the heating control unit 155 performs the filter heating operation when the operation time of the fan 95 after the filter 20 is attached to the air discharge duct 64 reaches a predetermined time. As a result, the viscosity of the ink adhering to the filter 20 is reduced, so that clogging of the filter 20 due to an increase in the viscosity of the ink can be reliably suppressed.

  According to the present embodiment, the heating control unit 155 performs the filter heating operation when the current value of the fan motor 96 is out of the normal current value range. That is, the filter 20 is heated when the current value of the fan motor 96 deviates from the normal current value range due to the degree of clogging of the filter 20 increasing and the flow path resistance of the filter 20 increasing. . Thereby, since the viscosity of the ink absorbed in the filter 20 falls, the clogging of the filter 20 due to the increase in the viscosity of the absorbed ink can be reliably suppressed.

(Modification of the first embodiment)
In the first embodiment described above, the heating controller 155 performs the filter heating operation even when the head controller 153 drives the actuator unit 21 of the head 1, that is, when ink is ejected from the head 1. However, when the ink is ejected from the head 1, the filter heating operation may not be performed. That is, the filter heating operation may be performed when ink is not ejected from the head 1. As described above, since the control device 100 controls the actuator unit 21 of the head 1 and the heater 91 not to be driven at the same time, the maximum driving power of the printer 101 can be lowered. The system can be made compact.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the main difference from the first embodiment is that the filter is heated by the heater in the first embodiment, but by the exhaust heat of the drying mechanism 31 in the second embodiment. . In the following, the same reference numerals are given to the same portions as those in the first embodiment described above, and the description thereof is omitted as appropriate. In the second embodiment, the heating control unit 155 is not provided, When the control device 100 performs both the air blowing operation and the image forming operation, the filter 20 is always heated.

  In the present embodiment, as shown in FIG. 11, the printer 101 includes a heating chamber 65 and tubes 66 and 67 that surround the drying heater 31 a of the drying mechanism 31 with a guide 29 b. The tube 66 connects the heating chamber 65 and one of the branch ducts 63 so as to communicate with each other. The tube 67 connects the heated greenhouse 65 and the external space S2 so as to communicate with each other. Further, the discharge port 64a of the air discharge duct 64 faces the outside of the housing 101a.

  In this configuration, when the air blowing operation is performed by the air blowing control unit 154, the air in the external space S <b> 2 is supplied to the heating chamber 65 through the tube 67. Here, when the drying control unit 156 drives the drying heater 31a to heat and dry the paper P after image formation, the heat is exhausted from the drying heater 31a (heat not supplied to the paper P by heat drying). Will occur. The air supplied to the heating chamber 65 is heated by the exhaust heat of the drying heater 31a. The air heated in the heating chamber 65 passes through the tube 67, merges with the air in the discharge space S1 introduced from the introduction port 61a in the branch duct 63, and is directed toward the discharge port 64a. 64 flows through. Therefore, the air heated in the heating chamber 65 passes through the filter 20 while heating the filter 20. As a result, the viscosity of the ink adhering to the filter 20 is lowered, so that the filter 20 can easily absorb the ink, and the entire filter can efficiently absorb the ink. As described above, according to the present embodiment, the filter 20 is heated using the exhaust heat of the drying heater 31a of the drying mechanism 31, so that it is not necessary to newly provide a heat source for heating the filter 20. In the present embodiment, the heating unit is configured by the heating chamber 65 and the tubes 66 and 67.

  As described above, in the second embodiment, the heating control unit 155 is not included, but the heating control unit 155 may be included. In this case, a valve is provided in the tube 67 or the like, and only when the heating determination unit 161 determines that heating of the filter 20 is necessary, the valve 20 is controlled to be opened, and the filter 20 is heated in the heating chamber 65. It is sufficient that the air is supplied.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described. In the third embodiment, the main difference from the first embodiment is that the filter is heated by the heater in the first embodiment. However, in the third embodiment, the filter includes a moisture-absorbing heat generating material, and the filter is humidified. It is a point which heats by supplying air. Below, the same code | symbol is attached | subjected about the location same as 1st Embodiment mentioned above, and the description is abbreviate | omitted suitably.

  In the present embodiment, the filter 20 includes a moisture absorption heat generating material that generates heat of adsorption due to moisture adsorption. When the heating determination unit 161 determines that the filter 20 needs to be heated, the heating control unit 155 drives the humidification pump 89. Thereby, the air near the air discharge port 81b in the discharge space S1 is humidified. The humidified air is introduced into the duct 60 from the introduction port 61 a by the air blowing operation by the blow control unit 154, blown through the duct 60 toward the discharge port 64 a, and adsorbed by the filter 20. become. As a result, the filter 20 is heated by the heat of adsorption, and the viscosity of the ink adhering to the filter 20 is lowered. Therefore, the filter 20 can easily absorb the ink, and the entire filter 20 can efficiently absorb the ink. It becomes. As described above, according to the present embodiment, since the filter 20 itself becomes a heat source, the viscosity of the ink absorbed by the filter 20 can be efficiently reduced. In order to prevent the paper P during image formation from getting wet, the transfer amount of the humidifying pump 89 during the image forming operation (particularly when ink is being ejected from the ink ejection head 1) is different from that at other times. It is preferable to reduce the amount. In the present embodiment, the heating control unit 155, the humidifying mechanism 80, and the ammeter 98 constitute a heating unit.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the above-described embodiment, the transport mechanism 16 includes the two belt rollers 6 and 7, the transport belt 8, the tension roller 10, and the platen 18. Alternatively, the paper P may be transported by a plurality of spur rollers or the like.

  Moreover, in 1st Embodiment mentioned above, in the humidification maintenance operation | movement, it was comprised so that humidified air might circulate, However, The structure discharged | emitted to air | atmosphere may be sufficient after crossing discharge space S1.

  In the second embodiment described above, the filter is heated by the exhaust heat of the drying mechanism 31. However, the heat of the power supply device provided in the housing 101 a of the printer 101 or the housing of the printer 101 is heated. The filter may be heated by exhaust heat generated from a substrate (including electronic components arranged on the substrate) provided in the body 101a.

  Moreover, in embodiment mentioned above, when the ventilation control part 154 is performing air blowing operation, the heating control part 155 is made to perform filter heating operation, However, The ventilation control part 154 performs air blowing operation. When not performed, the heating control unit 155 may be configured to perform the filter heating operation. For example, the filter heating operation may be performed during the humidifying maintenance operation.

  In the above-described embodiment, the air blowing operation is performed before the image forming operation is started. However, since the ink mist is generated after the image forming operation is started, the image forming operation is started. The structure which has not performed air blowing operation before may be sufficient.

  Further, in the above-described embodiment, the duct 60 is configured to introduce air containing ink mist from the air introduction duct 61 having a rectangular frame in plan view. However, the duct 60 is simply disposed downstream of the head 1 in the transport direction. The structure provided with the inlet may be used. For example, one end of the air discharge duct 64 may be open to the downstream side in the transport direction of the head 1. Since the ink mist generated in the ejection space S1 by the air flow generated by the conveyance of the paper P is caused to flow downstream in the conveyance direction of the head 1, the effect of the introduction of the duct 60 on the downstream side in the conveyance direction of the head 1 is effective. Ink mist can be sucked.

  In the above-described embodiment, the humidification mechanism 80 includes the humidification pump 89 and the water tank 85, but various other means may be used as long as the air can be humidified. For example, the humidification pump 89 may be omitted and humidification may be performed using only the water tank 85. Further, humidification can be achieved by further using heating means such as a heater, using ultrasonic humidification means, or disposing a porous member or cloth such as sponge soaked in water in the air flow path. You may go.

  Furthermore, the protrusion 41a is not limited to being movable as in the above-described embodiment. For example, the protrusion may be fixed to the head holder so as not to move, and the relative position of the cap tip with respect to the ejection surface may be constant. In this case, by raising and lowering the conveying surface of the head holder or the conveying belt, the cap tip is brought into contact with the conveying surface and the head 1 is raised and lowered. For example, when the protrusion 41a is in the contact position, the discharge surface 1a is separated from the transport surface more than the protrusion 41a so as to widen the interval between the discharge surface 1a and the transport surface. Conversely, when the protruding portion 41a is at the separation position, the ejection surface 1a is brought closer to the transport surface than the protruding portion 41a.

  The recording medium is not particularly limited to the paper P, and various recording media may be used. A plurality of heads 1 may be provided.

  The present invention can be applied to both a line type and a serial type, and is not limited to a printer, and can also be applied to a facsimile, a copier, and the like. In addition, although a piezoelectric actuator is used to discharge droplets, other methods (for example, a resistance heating method or an electrostatic method) may be used.

DESCRIPTION OF SYMBOLS 1 Ink discharge head 20 Filter 60 Duct 61a Inlet 64a Outlet 91 Heater 95 Fan S1 Discharge space

Claims (8)

An ink ejection head for ejecting ink for forming an image on a recording medium;
A duct having an inlet and an outlet;
A blowing unit that introduces air in a discharge space from which the ink is discharged into the duct from the introduction port, and blows air toward the discharge port;
A filter made of an ink absorber provided in the duct;
Heating means for heating the upstream portion in the air blowing direction of the filter,
The filter includes a hygroscopic exothermic material,
The inkjet recording apparatus, wherein the heating unit is a humidifying unit that humidifies the air in the discharge space. An ink ejection head for ejecting ink for forming an image on a recording medium;
A duct having an inlet and an outlet;
A blowing unit that introduces air in a discharge space from which the ink is discharged into the duct from the introduction port, and blows air toward the discharge port;
A filter made of an ink absorber provided in the duct;
Heating means for heating the upstream portion in the air blowing direction of the filter,
The filter is detachably attached to the duct,
The ink jet recording apparatus according to claim 1, wherein the heating unit performs the heating when an operating time of the air blowing unit after the filter is attached reaches a predetermined time. An ink ejection head for ejecting ink for forming an image on a recording medium;
A duct having an inlet and an outlet;
A blowing unit that introduces air in a discharge space from which the ink is discharged into the duct from the introduction port, and blows air toward the discharge port;
A filter made of an ink absorber provided in the duct;
Heating means for heating the upstream portion in the air blowing direction of the filter,
The air blowing means includes a fan and a motor that rotates the fan,
The heating means includes a current value detection unit that detects a current value of the motor,
The ink jet recording apparatus, wherein the heating means performs the heating when the current value is out of a predetermined range.   The inkjet recording apparatus according to claim 2, wherein the heating unit is a heater. The image forming apparatus further includes a drying unit configured to heat and dry the recording medium to which the ink ejected by the ink ejection head is attached. The heating unit performs the heating by exhaust heat generated by the heating and drying of the drying unit. An ink jet recording apparatus according to claim 2 or 3.   The inkjet recording apparatus according to claim 1, wherein the heating unit performs the heating when the blowing unit performs the blowing.   The inkjet recording apparatus according to claim 1, wherein the heating unit heats the entire filter.   The inkjet recording apparatus according to claim 1, wherein the heating unit performs the heating when the ink is not ejected from the ink ejection head.

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