JP4720477B2 - Liquid ejecting apparatus and recording apparatus - Google Patents

Description

  The present invention relates to a liquid ejecting apparatus and a recording apparatus. More specifically, the present invention relates to a liquid ejecting apparatus and a recording apparatus that allow liquid ejected from an opening of a nozzle plate attached to a liquid ejecting head to adhere to a recording material.

  In a liquid ejecting apparatus in which a resolution is required for a recorded image, droplets ejected from an opening of a nozzle plate are refined to about several pl. Since the mass of such a fine droplet is very small, once it is ejected from the nozzle plate, the kinetic energy is rapidly lost due to the viscous resistance of the atmosphere. For example, a droplet of less than 3 pl has a velocity of approximately zero when it travels about 3 mm in the atmosphere. The fine droplets that have lost their kinetic energy are almost balanced by the drop motion due to gravitational acceleration and the viscous resistance force of the atmosphere, and it takes a long time to finish dropping.

  It has also been considered to increase the liquid ejection speed in order to give larger kinetic energy to the droplets. However, when the ejection speed from the nozzle plate is increased, the droplets break up when they leave the nozzle plate, and very fine droplets called ink mist are generated. In addition, it has been found that, as the jetting speed increases, the viscous resistance of the atmosphere acting on each droplet also increases, so that the reach distance of the droplet is rather shortened.

  The floating droplets generated as a result of the various phenomena as described above are called aerosols and float around the operation area of the liquid ejecting head. Most of the aerosol eventually adheres to each part in the liquid ejecting apparatus. Further, a part of the aerosol floats to the outside of the liquid ejecting apparatus and defaces the periphery of the liquid ejecting apparatus.

  In the liquid ejecting apparatus, when the aerosol adheres to the transport path of a recording material such as a platen, the recording material transported next is contaminated. In addition, if the aerosol adheres to the electric circuit, the rotary scale, the linear scale, or various optical sensors of the liquid ejecting apparatus, a malfunction may be caused.

Patent Document 1 below discloses a structure of a liquid ejecting apparatus that reduces an aerosol by forming an electric field between a nozzle plate and a platen so that a Coulomb force directed toward an object to be processed acts on the droplets. According to this, it is described that the droplets can surely reach the object to be processed and the generation of the aerosol can be prevented.
JP 2004-202867 A

  On the other hand, in the liquid ejecting apparatus provided with the aerosol generation preventing structure described in Patent Document 1, when performing so-called borderless printing, in which an image is recorded without leaving a margin until the peripheral edge of the recording material is full. There is. In such a case, the liquid is ejected to a region slightly wider than the width of the recording material in consideration of tolerances of the liquid ejecting apparatus itself and variations in the size of the recording material. Accordingly, in the vicinity of the periphery of the recording material, the liquid is discharged to the area where the recording material does not exist from the beginning, and aerosol is inevitably generated. For this reason, it has been found that in the recording material printed with no border, the back surface of the peripheral edge of the recording material tends to be contaminated by the aerosol. It has also been found that such contamination on the back surface of the peripheral edge portion occurs more greatly at the front and rear edges in the recording material conveyance direction. Therefore, it is possible to actively collect aerosol generated near the front and rear ends of the recording material by forming an electric field before and after the area where the liquid is ejected toward the recording material in the conveyance direction of the recording material. Proposed and has a certain effect.

  However, as described above, the liquid disposed as an aerosol adheres to the electrodes arranged for the purpose of collecting the aerosol and accumulates in due course. Since the solvent contained in the liquid does not dry much, the periphery of the electrode becomes wet with the accumulated liquid. Since the liquid that is not dried has conductivity, the area where the electric field is formed changes when the area wetted with the liquid extends to the outside of the electrode, or the potential of the electrode changes to change the expected aerosol collection effect. May not be obtained. In addition, when the liquid adheres to the inside of the platen, the intended effect of preventing the backside contamination of the recording material is lost because the electric field is formed outside the front end or the rear end of the recording material. Cannot be obtained.

  Accordingly, in order to solve the above-described problem, as a first embodiment of the present invention, a conductive nozzle plate having an opening is provided, and the reciprocating movement is performed on the recording material from the opening to the surface of the recording material. A liquid ejecting head that ejects liquid toward the plate, a platen that is positioned in contact with the recording material from the back surface at a position facing the nozzle plate in a direction in which the liquid is ejected, and a recording material on the same side as the platen, It is arranged around the platen having the rib portion and the absorbing member, and is formed between a peripheral electrode having a potential different from that of the nozzle plate, an opposing region facing the nozzle plate on the surface of the platen, and the peripheral electrode. There is provided a liquid ejecting apparatus including a separation unit that has wettability and does not hold a liquid that has come flying. Thereby, the liquid is not electrically coupled between the peripheral electrode and the counter area, and the original electrical specifications of the peripheral electrode are maintained for a long period of time.

  According to one embodiment, in the liquid ejecting apparatus, the separation unit has a steep slope that sandwiches an acute angle with respect to the vertical line. Thereby, since the liquid adhering to the separation unit falls due to its own mass, a large amount of liquid is not accumulated in the separation unit.

  According to another embodiment, in the liquid ejecting apparatus, the separation unit has a sharp tip protruding from the platen toward the back surface of the recording material. As a result, there is no horizontal surface in the separation part where the liquid is easily held, and the continuity of the ink is cut off at the tip part. Therefore, the liquid does not form an electrical connection across the tip of the separation part.

  According to another embodiment, in the liquid ejecting apparatus, the separation unit has a height that does not reach the back surface of the recording material supported by the platen. Thereby, the back surface of the recording material is not contaminated by the liquid adhering to the separation portion. In addition, the separation part is not worn by touching the recording material to be conveyed.

  According to another embodiment, in the liquid ejecting apparatus, at least the surface of the separation portion is formed of a silicon-based water repellent material or a fluorine-based water repellent material. Thereby, since the wettability of the liquid in the separation unit is reduced, the liquid is not held in the separation unit.

  Further, according to another embodiment, in the liquid ejecting apparatus, the separation unit deposits the base part integrally formed with the platen and the fine particles of the silicon-based water repellent material or the fluorine-based water repellent material so as to cover the surface of the base part. And a water repellent layer to be coated. As a result, the wettability of the separation part by the liquid is remarkably reduced, so that the continuity of the liquid is cut off in the separation part.

  Further, according to another embodiment, the liquid ejecting apparatus further includes a discharge switch that connects the peripheral electrode to a ground potential under a specific condition. Thereby, an unnecessary electric field can be extinguished reliably and a required electric field can be made to act effectively.

  Further, as a second embodiment of the present invention, a recording head having a conductive nozzle plate with an opening formed therein and ejecting ink from the opening toward the recording material while reciprocating on the recording material; A platen that supports and positions the recording material from the back surface at a position facing the nozzle plate in the direction in which the ink is ejected, and is provided on the same side of the platen as the recording material on the same side as the platen and around the platen so as to face the nozzle plate. Formed between a peripheral electrode having a potential different from that of the nozzle plate and an opposing region facing the nozzle plate on the surface of the platen and the peripheral electrode, and has low wettability with respect to ink and does not hold the flying ink A recording apparatus. Thereby, also in the recording apparatus, the same effect as the liquid ejecting apparatus can be obtained.

  The summary of the invention does not enumerate all necessary features of the present invention. Further, a sub-combination of these feature groups can be an invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a perspective view showing an overview of an ink jet recording apparatus 10 according to one embodiment, and is drawn in a state where an upper case 110 as a cover is opened. As shown in FIG. 1, the ink jet recording apparatus 10 includes a lower case 120 serving as a base of the apparatus, an upper case 110 that forms a casing together with the lower case 120, and a paper support attached to the rear portion of the lower case 120. 130 and a discharge tray 140 formed on the front surface of the lower case 120. Further, the ink jet recording apparatus 10 includes a platen 150 disposed horizontally in the lower case 120 and a carriage 160 disposed above the platen 150 inside the casing. In FIG. 1, a recording sheet 170 as a recording material loaded in the paper support 130 is indicated by a dotted line.

  In the ink jet recording apparatus 10 as described above, the recording paper 170 is taken into the inside of the paper support 130 one by one by a feeding unit (not shown), and then sent out onto the platen 150 by a conveying unit (not shown). Further, the paper is sent to the discharge tray 140 by a discharge unit (not shown). In each of the feeding unit, the conveyance unit, and the discharge unit, the recording paper 170 is fed, conveyed, or discharged by being sandwiched between a driving roller that is rotationally driven and a driven roller that is driven by the driving roller.

  In the ink jet recording apparatus 10, the carriage 160 is disposed above the platen 150. The carriage 160 reciprocates in a direction orthogonal to the conveyance direction of the recording paper 170. Therefore, the entire upper surface of the recording paper 170 can be scanned by the carriage 160 by alternately conveying the recording paper 170 and reciprocating the carriage 160. Accordingly, the carriage 160 can perform a recording operation in an arbitrary area on the upper surface of the recording paper 170.

  2 is a perspective view showing the internal mechanism 20 of the ink jet recording apparatus 10 shown in FIG. 1 with the internal frame 210 including the side portions 212 and 214 extracted. As shown in the figure, the internal mechanism 20 includes an internal frame 210 disposed substantially vertically rearward, and a pair of side surface portions 212 and 214 extending forward in parallel from both side end portions thereof. It is mainly formed inside the area defined by

  A horizontal guide shaft 220 is mounted inside the inner frame 210. Both ends of the guide shaft 220 are supported by the side portions 212 and 214 and fixed to the inner frame 210 in parallel. Since the carriage 160 is penetrated and supported by the guide shaft 220, the carriage 160 moves horizontally along the guide shaft 220.

  Behind the carriage 160, a pair of pulleys 232 and 234 and a timing belt 230 hung on the pulleys 232 and 234 are disposed on the front surface of the inner frame 210. One pulley 234 is rotationally driven by a carriage motor 236. Further, the timing belt 230 is coupled to the rear portion of the carriage 160 at one place. Accordingly, the carriage 160 can be reciprocated according to the operation of the carriage motor 236.

  The carriage 160 also includes an ink cartridge 162 loaded from above and a recording head 164 mounted on the lower surface of the carriage 160. Further, the recording head 164 includes a metal nozzle plate 166 having an opening 168 for ejecting ink. Accordingly, the carriage 160 ejects ink supplied from the ink cartridge 162 downward.

  Furthermore, the carriage 160 is coupled to an electronic circuit 250 behind the internal frame 210 via a tape-shaped multicore cable 240. Since the multi-core cable 240 flexes flexibly as the carriage 160 moves, it does not hinder the reciprocating movement of the carriage 160.

  A platen 150 is disposed below the region where the carriage 160 reciprocates as described above. The platen 150 supports the recording paper 170 passing under the carriage 160 from below, and keeps the distance between the nozzle plate 166 and the recording paper 170 constant. Further, a depressed portion 152 is formed on the upper surface of the platen 150, and the absorbing member 260 is accommodated in the depressed portion 152. The absorbing member 260 absorbs ink ejected from the recording head 164 toward an area where the recording paper 170 does not exist.

  Note that ink adheres to the absorbing member 260 sequentially as the operation time of the ink jet recording apparatus 10 increases. When the recording paper 170 comes into contact with such an absorbing member 260, the back surface is contaminated with ink. Therefore, a rib-like portion is formed on the upper surface of the platen 150, and the recording paper 170 is lifted and supported from below to prevent contact between the two. Specifically, a gap of about 2 to 4 mm is provided between the recording paper 170 and the absorbing member 260. An interval of about 1 mm is also maintained between the surface of the nozzle plate 166 and the surface of the recording paper 170.

  The material of the absorbing member 260 is selected with emphasis on the liquid absorption speed on the surface. That is, the absorbing member 260 directly receives the ink that has been ejected from the nozzle plate 166 and has not adhered to the recording paper 170. At this time, if the absorption speed of the absorbing member 260 is slow, the ink generates a so-called milk crown by an impact that collides with the surface of the absorbing member 260. Fine ink droplets are generated from the periphery of the milk crown, which also causes aerosol generation. Therefore, it is desirable that the absorbing member 260 has a high absorption rate, in other words, a high porosity.

  On the other hand, the absorption capacity of the absorption member 260 having a high porosity as described above must be reduced. Therefore, a waste liquid absorbing member 262 having a larger absorption capacity is disposed below the platen 150, and this part and the absorbing member 260 are partially contacted. For the waste liquid absorbing member 262, a material having a large absorption capacity due to capillary action is selected along with its absorption capacity. Therefore, the ink absorbed by the absorbing member 260 is sequentially absorbed by the waste liquid absorbing member 262 having higher absorbing power. Thereby, the absorption speed and absorption force of the absorption member 260 are maintained over a long period of time.

  A transport driving roller 282 and a transport driven roller 284 are disposed behind the platen 150 as described above to form a transport unit 280. The transport driving roller 282 is rotationally driven by a transport motor 286 disposed behind the inner frame 210. Further, the conveyance driven roller 284 presses the recording paper 170 against the conveyance driving roller 282. Accordingly, the conveyance driven roller 284 is rotated along with the rotation of the conveyance driving roller 282 and the recording paper 170 is sent out onto the platen 150. Since ink is ejected from the carriage 160 on the platen 150 as described above, an image can be recorded by attaching ink to the upper surface of the recording paper 170.

  In addition, a discharge driving roller 292 and a discharge driven roller 294 are arranged in front of the platen 150 to form a discharge unit 290. The discharge drive roller 292 is rotationally driven by the power distributed from the transport motor 286 described above. Further, the discharge driven roller 294 presses the recording paper 170 that has passed through the platen 150 against the discharge driving roller 292. Accordingly, as the discharge driving roller 292 rotates, the discharge driven roller 294 is rotated and the recording paper 170 is sent out from the platen 150 to the outside.

  Further, in the internal mechanism 20, a cap member 270 is disposed on the side of the platen 150 on the side surface 212 side. The cap member 270 can move up and down, and rises when the carriage 160 stops at the home position close to the side surface portion 212 to seal the lower surface of the nozzle plate 166. Further, the inside of the cap member 270 is coupled to the pump unit 272. The pump unit 272 can suck ink adhering to the surface of the nozzle plate 166. The ink sucked by the pump unit 272 is absorbed by the waste liquid absorbing member 262 through a pipe (not shown).

  Still further, a wiping means 274 is disposed between the platen 150 and the cap member 270. When the carriage 160 released from the sealing by the cap member 270 passes above, the wiping means 274 wipes and cleans the lower surface of the nozzle plate 166.

  FIG. 3 is a perspective view schematically showing the structure of the aerosol collecting mechanism 30 formed inside the ink jet recording apparatus 10 as described above. FIG. 3 also shows the detailed shape of the platen 150.

  As shown in the figure, the platen 150 is provided with a rib portion 154 that protrudes upward, and the recording paper 170 is supported from the back at the upper end of the platen 150 and positioned in the vertical direction. Further, a depressed portion 152 is formed around the region where the rib portions 154 are arranged, and the absorbing member 260 is accommodated therein. On the other hand, in the recording operation of the ink jet recording apparatus 10, the nozzle plate 166 reciprocates together with the carriage 160 in the direction indicated by the arrow X in the drawing. Therefore, the ink ejected from the opening 168 adheres to the recording paper 170 in the region positioned by the rib portion 154. Therefore, the region where the rib portion 154 and the depressed portion 152 are disposed is a facing region facing the opening 168 of the nozzle plate 166.

  Further, the recording paper 170 is conveyed in the direction indicated by the arrow Y in the drawing with respect to the platen 150 as described above. Here, with respect to the conveyance direction, the conveyance unit side absorption member 181 and the discharge unit side absorption member 182 are arranged before and after the opposite region, that is, on the conveyance unit 280 side and the discharge unit 290 side of the opposite region, respectively.

  Further, the transport unit side absorbing member 181 and the discharge unit side absorbing member 182 are individually connected to one end of the potential difference generating unit 330 via an electrode, which will be described later, and a discharge unit side discharge switch 334 and a transport unit side discharge switch 336, respectively. Connected to. The other end of the potential difference generating means 330 is coupled to the nozzle plate 166 via the nozzle plate side discharge switch 332 and the short circuit protection resistor 320. Here, the nozzle plate side discharge switch 332, the discharge unit side discharge switch 334, and the transport unit side discharge switch 336 operate in a specific combination by a common control signal, and form various operation modes as described later.

  Furthermore, the platen 150 includes a separating portion 156 formed so as to surround the depressed portion 152. The separation unit 156 is raised from the surface of the platen 150 and is continuously formed at least between the facing region and the conveyance unit side absorption member 181 or the discharge unit side absorption member 182.

  FIG. 4 is a schematic cross-sectional view for explaining the operation of the aerosol collecting mechanism 30 as described above. FIG. 4 shows a state where the front end of the recording paper 170 reaches the platen 150 in the recording operation of the ink jet recording apparatus 10. In addition, the same reference numerals are assigned to components common to the other drawings, and redundant description is omitted.

  As shown in the figure, the lower surfaces of the conveyance unit side absorption member 181 and the discharge unit side absorption member 182 accommodated in the platen 150 are in contact with the conveyance unit side peripheral electrode 183 and the discharge unit side peripheral electrode 184, respectively. Further, the transport part side peripheral electrode 183 and the discharge part side peripheral electrode 184 are connected to the potential difference generating means 330 via the discharge part side discharge switch 334 and the transport part side discharge switch 336, respectively. Here, as the material of the transport part side peripheral electrode 183 and the discharge part side peripheral electrode 184, stainless steel, nickel-plated iron, iron containing duralumin, chromium or molybdenum, tungsten, titanium, alloys containing titanium, etc. It can be formed of a high metal. Moreover, it can also form integrally with the platen 150 by embedding, sticking, or two-body molding using materials, such as carbon, a metal, and a conductive polymer. Further, an amorphous semiconductor such as selenium or silicon or a metal can be formed by partial vapor deposition on the platen 150.

Moreover, the conveyance part side absorption member 181 and the discharge part side absorption member 182 are formed of the porous material which has electroconductivity in itself. Materials that can be used for such applications include foams after mixing conductive materials such as metal and carbon in resins such as polyethylene and polyurethane, and metal and carbon in resin foam materials such as polyethylene and polyurethane. A material to which a conductive material such as a material is attached or a material that is plated can be used. Moreover, what impregnated electrolyte solution to resin foam materials, such as polyethylene and a polyurethane, can also be used. Since these materials have a surface resistance of 10 ⁸ Ω or less, they can be handled as conductive materials.

  As described above, the recording sheet conveyed in the direction of the arrow T with respect to the platen 150 including the conveyance unit side absorption member 181 and the discharge unit side absorption member 182, the conveyance unit side peripheral electrode 183, and the discharge unit side peripheral electrode 184. 170 reaches the rib portion 154 of the platen 150, but does not yet reach the upper portion of the discharge portion side absorbing member 182. For this reason, the surface of the discharge part side absorption member 182 and the lower surface of the nozzle plate 166 are directly opposed to each other. At this time, the discharge portion side discharge switch 334 connects the discharge portion side peripheral electrode 184 to the potential difference generating means 330. On the other hand, the transport unit side discharge switch 336 connects the transport unit side absorbing member 181 to the ground. Accordingly, an electric field is formed between the nozzle plate 166 and the discharge portion side absorbing member 182 due to the potential difference generated by the potential difference generating means 330.

  On the other hand, the ink is pushed out from the opening 168 of the nozzle plate 166. Here, the ink pushed out from the opening 168 forms an ink column 340 that hangs down from the nozzle plate 166 at the moment immediately before the ink droplet 342 is formed, and then a part of the ink column 340 is detached from the lower end to form the ink droplet 342. . Although the ink droplets 342 are charged, many of them adhere to the recording paper 170 as ink droplets 344 to form an image.

  Further, as described above, an electric field is formed between the nozzle plate 166 and the discharge portion side absorbing member 182. In this electric field, since the Coulomb force acts on the charged ink droplet 342, the ink droplet 342 obtains kinetic energy, moves downward without being decelerated, and reaches the discharge portion side absorbing member 182. . Therefore, the generation of aerosol is suppressed in the vicinity of the region where the electric field is formed. In this way, the back surface is less contaminated with aerosol near the front end of the recording paper 170.

  FIG. 5 shows a state in which the advanced recording paper 170 is positioned above both the conveyance unit side absorption member 181 and the discharge unit side absorption member 182. At this time, the nozzle plate side discharge switch 332, the discharge unit side discharge switch 334, and the transport unit side discharge switch 336 individually connect the nozzle plate 166, the transport unit side peripheral electrode 183, and the discharge unit side peripheral electrode 184 individually to the ground. The potential difference generating means 330 is disconnected. Therefore, there is no potential difference between any members, and no electric field is formed.

  FIG. 6 is a schematic cross-sectional view for explaining the operation of the aerosol collecting mechanism 30 in another state. That is, FIG. 6 shows a state immediately before the trailing edge of the recording paper 170 passes through the platen 150 in the recording operation of the ink jet recording apparatus 10. In addition, the same reference numerals are assigned to components common to the other drawings, and redundant description is omitted.

  As shown in the figure, in this state, the trailing edge of the recording paper 170 conveyed in the direction of the arrow T tends to pass over the rib portion 154 of the platen 150, but above the discharge portion side absorbing member 182. Still not reach. For this reason, the surface of the conveyance part side absorption member 181 and the lower surface of the nozzle plate 166 face each other directly. At this time, the nozzle plate-side discharge switch 332 connects the nozzle plate 166 and the potential difference generating means 330. The transport unit side discharge switch 336 connects the transport unit side peripheral electrode 183 to the other end of the potential difference generating unit 330.

  Thus, the potential difference generated by the potential difference generating means 330 forms an electric field between the nozzle plate 166 and the discharge portion side absorbing member 182. On the other hand, since the ink droplets 342 discharged from the nozzle plate 166 are charged, kinetic energy is obtained in the electric field, and the ink droplets 342 move downward without being decelerated and reach the conveyance unit side absorption member 181. Generation of aerosol is suppressed. In this way, the back surface is less contaminated with aerosol near the front end of the recording paper 170.

As described above, when the front end or the rear end of the recording paper 170 passes above the platen 150, the discharge portion side peripheral electrode 184 or the transport portion side peripheral electrode disposed before and after the platen 150 in the transport direction of the recording paper 170. By forming an electric field using 183, it is possible to effectively suppress the adhesion of aerosol to the back surface of the recording paper 170. Further, the backside contamination of the recording paper 170 was also reduced.

  In the aerosol collecting mechanism 30 having the above-described structure, in order to prevent the formation of aerosol by applying a Coulomb force to the ink droplet 342, the electric field strength formed between the electrodes is about 100 kV / m at the maximum. It is desirable to cause the potential difference generating means 330 to generate such a potential difference.

  Further, in the above embodiment, the discharge portion side peripheral electrode 184 or the transport portion side peripheral electrode 183 is connected to the positive electrode side of the potential difference generating means 330, and the nozzle plate 166 is connected to the negative electrode side of the potential difference generating means 330. However, the same function can be realized even if all the polarities are reversed and connected. Moreover, the wiring in the aerosol collecting mechanism 30 can be simplified by setting the potential at one end of the potential difference generating means 330 to the ground potential.

  FIG. 7 is a diagram showing the structure of the embodiment as described above. As shown in the figure, in this embodiment, the nozzle plate 166 is connected to the ground potential. One end of the potential difference generating means 330 is also connected to the ground potential. Therefore, the nozzle plate side discharge switch 332 used in the embodiment shown in FIGS. 4 to 6 can be omitted. Further, the above-described operation can be realized by simple control in which the discharge unit side discharge switch 334 or the transport unit side discharge switch 336 is operated in a complementary manner. In view of the function, the short-circuit protection resistor 320 is moved to the platen 150 side with respect to the potential difference generating means 330.

  Further, in the aerosol collecting mechanism 30 described above, some of the ink droplets 342 that have not adhered to the recording paper 170 also adhere to portions other than the discharge portion side absorbing member 182 on the upper surface of the platen 150. However, in the ink jet recording apparatus 10, the separation unit 156 is formed between the discharge unit side absorption member 182 or the conveyance unit side absorption member 181 and the opposing region at the center of the platen 150.

  As shown in the drawings of FIGS. 3 to 6, the separating unit 156 is formed from the surface of the depressed portion 152 of the platen 150 extending upward, and the discharge unit side absorbing member 182 or the conveying unit side absorbing member 181. It is formed so as to rise from above the platen 150 due to the steeply rising slope. For this reason, both surfaces of the separation part 156 form a steep surface near the vertical. However, the height of the separation portion 156 is stopped at a height that does not reach the back surface of the recording paper 170 on the rib portion 154. Furthermore, the upper end of the separation part 156 forms a sharp tip, and there is no horizontal plane.

  In such a separation unit 156, the adhering ink droplet 342 slides down without being held on the surface of the separation unit 156, and is eventually absorbed by the discharge unit side absorption member 182 or the absorption member 260. Therefore, a continuous ink film is not held between the discharge unit side absorption member 182 or the conveyance unit side absorption member 181 and the absorption member 260. Therefore, the discharge portion side peripheral electrode 184 or the transport portion side peripheral electrode 183 and the absorbing member 260 are not electrically coupled by the conductive ink. For this reason, the electric field formed above the discharge part side peripheral electrode 184 or the transport part side peripheral electrode 183 does not change, and the initial performance of the aerosol collecting mechanism 30 is stabilized over a long period of time.

  In view of the above functions, at least the surface of the separation portion 156 is preferably a water repellent surface 157 formed of a material having low wettability with respect to ink. Specifically, when the ink is water-based, a water-repellent resin material such as silicon resin or fluororesin can be exemplified as a preferable material. Even if the separation part 156 is not entirely formed of a water repellent resin, the same effect can be obtained by covering the base of the separation part 156 formed integrally with the platen 150 with the water repellent resin. Furthermore, the separation part 156 having a highly water-repellent surface that can be said to be almost super water-repellent can be formed by attaching a water-repellent resin as fine particles of submicron level to form a fine rough surface.

  As described above, by providing the separation portion 156 between the opposing region on the platen 150 and the peripheral electrode, it is possible to prevent the peripheral electrode and the opposing region from being electrically coupled by the adhered ink. Therefore, the initial performance of the peripheral electrode is maintained for a long period of time, and contamination of the recording material by the aerosol is effectively prevented.

  In the above-described embodiment, the specific configuration has been described by taking the ink jet recording apparatus 10 as an example. However, the liquid ejecting apparatus may be, for example, a color material ejecting apparatus or an organic EL display in manufacturing a color filter for a liquid crystal display. In addition, it can be implemented as an electrode forming device in the manufacture of FED (surface emitting display), a sample ejecting head used for biochip manufacturing, a sample ejecting head as a precision pipette, a device for drawing pictures, characters, etc. However, it is not limited to these.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. In addition, it is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

FIG. 2 is a perspective view of the overall appearance of the ink jet recording apparatus 10. FIG. 3 is a perspective view showing an internal mechanism 20 extracted from the ink jet recording apparatus 10. The figure which shows the structure of the aerosol collection mechanism 30. FIG. The schematic diagram explaining operation | movement of the aerosol collection mechanism 30. FIG. The schematic diagram explaining operation | movement of the aerosol collection mechanism 30 in another operation state. Furthermore, the schematic diagram explaining operation | movement of the aerosol collection mechanism 30 in another operation state. The figure which shows the other structure of the aerosol collection mechanism 30. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inkjet recording device, 20 internal mechanism, 30 aerosol collection mechanism, 110 upper case, 120 lower case, 130 paper support, 140 discharge tray, 150 platen, 152 depression part, 154 rib part, 156 separation part, 160 carriage, 162 Ink cartridge, 164 recording head, 166 nozzle plate, 168 aperture, 170 recording paper, 181 transport unit side absorbing member, 182 discharge unit side absorbing member, 183 transport unit side peripheral electrode, 184 discharge unit side peripheral electrode, 210 internal frame, 212, 214 Side surface portion, 220 Guide shaft, 230 Timing belt, 232, 234 Pulley, 236 Carriage motor, 240 Multi-core cable, 250 Electronic circuit, 260 Absorbing member, 262 Waste liquid absorbing member, 270 Cap member 272 Pump unit, 274 Wiping means, 280 Conveying section, 282 Conveying drive roller, 284 Conveying driven roller, 286 Conveying motor, 290 Discharging section, 292 Discharging driving roller, 294 Discharging driven roller, 320 Short-circuit protection resistance, 330 Potential difference generating means 332 Nozzle plate side discharge switch, 334 Discharge unit side discharge switch, 336 Transport unit side discharge switch, 340 Ink column, 342, 344 Ink droplet

Claims (8)

A liquid ejecting head that has a conductive nozzle plate with an opening formed therein and ejects liquid from the opening toward the surface of the recording material while reciprocating on the recording material;
A platen positioned in contact with the recording material from the back surface at a position facing the nozzle plate in a direction in which the liquid is ejected;
A peripheral electrode disposed on the periphery of the platen on the same side as the platen with respect to the recording material, and having a different potential from the nozzle plate;
A liquid ejecting apparatus comprising: a separation unit that is disposed between a counter region facing the nozzle plate on the surface of the platen and the peripheral electrode, and that does not hold the liquid that has flown with low wettability with respect to the liquid.   The liquid ejecting apparatus according to claim 1, wherein the separation unit has a steep slope that sandwiches an acute angle with respect to a vertical line.   The liquid ejecting apparatus according to claim 1, wherein the separation unit has a sharp tip protruding from the platen toward the back surface of the recording object.   The liquid ejecting apparatus according to claim 1, wherein the separation unit has a height that does not reach a back surface of the recording material supported by the platen.   The liquid ejecting apparatus according to claim 1, wherein at least a surface of the separation portion is formed of a silicon-based water repellent material or a fluorine-based water repellent material.   6. The separation part includes a base part formed integrally with the platen, and a water repellent layer that deposits fine particles of the silicon water repellent material or the fluorine water repellent material to cover the surface of the base part. The liquid ejecting apparatus according to 1.   The liquid ejecting apparatus according to claim 1, further comprising a discharge switch that connects the peripheral electrode to a ground potential under a specific condition. A recording head having a conductive nozzle plate with an opening formed therein, and ejecting ink from the opening toward the recording material while reciprocating on the recording material;
A platen for supporting and positioning the recording material from the back surface at a position facing the nozzle plate in a direction in which the ink is ejected;
A peripheral electrode provided on the same side as the platen with respect to the recording material, facing the nozzle plate around the platen, and having a different potential from the nozzle plate;
A recording apparatus comprising: a separation unit that is formed between an opposing region facing the nozzle plate on the surface of the platen and the peripheral electrode, and has a low wettability with respect to the ink and does not hold the flying ink.

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