CN110382242B

CN110382242B - Ink jet recording apparatus

Info

Publication number: CN110382242B
Application number: CN201880015574.2A
Authority: CN
Inventors: 有马崇博; 猪狩光雄; 冈野守; 宫尾明
Original assignee: Hitachi Industrial Equipment Systems Co Ltd
Current assignee: Hitachi Industrial Equipment Systems Co Ltd
Priority date: 2017-06-20
Filing date: 2018-03-30
Publication date: 2021-01-01
Anticipated expiration: 2038-03-30
Also published as: JP7013461B2; WO2018235378A1; CN110382242A; JPWO2018235378A1

Abstract

An inkjet recording apparatus includes: a nozzle for forming ink particles; a charging electrode for charging the ink particles; a deflection electrode for deflecting the charged ink particles; and a print head capable of discharging the deflected ink particles to print on a print target, wherein a collecting member that collects floating ink is disposed between the print head and the print target, and the collecting member has an opening through which the ink particles discharged from the print head pass.

Description

Ink jet recording apparatus

Technical Field

The present invention relates to an ink jet recording apparatus that continuously ejects ink from nozzles to print on an object to be printed.

Background

Since the ink jet recording apparatus performs printing by ejecting ink from the ink ejection port of the print head, it is possible to perform printing on a print medium without contact. However, when the distance between the print head and the print medium is close, the ink may bounce back to the print head side when colliding with the print medium, and the surface of the print head may be contaminated.

In addition, the ink rebounded is attracted to the deflection electrode inside the print head, and this may contaminate the electrode and degrade the print quality.

As a background technique for solving this problem, japanese patent application laid-open No. 2017-1275 (patent document 1) is known. This publication describes "an ink jet recording apparatus that houses nozzles for discharging ink and printing on a print medium, wherein an ink recovery device that recovers floating ink by electrostatic force is provided on a side surface of the print head".

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-1275

Disclosure of Invention

Problems to be solved by the invention

In patent document 1, since the ink recovery device is provided on the side surface of the print head, there is a problem that an installation space for the ink recovery device is required on the side surface of the print head.

Accordingly, an object of the present invention is to provide an ink jet recording apparatus capable of suppressing contamination of a print head by floating ink in a small space.

Means for solving the problems

In order to solve the above problem, a preferred example of the present invention provides an inkjet recording apparatus including: a nozzle for forming ink particles; a charging electrode for charging the ink particles; a deflection electrode for deflecting the charged ink particles; and a print head capable of discharging the deflected ink particles to print on a print target, wherein a collecting member that collects the floating ink is disposed between the print head and the print target, and the collecting member has an opening through which the ink particles discharged from the print head pass.

Effects of the invention

According to the present invention, an inkjet recording apparatus capable of suppressing contamination of a print head by floating ink in a small space can be obtained.

Drawings

Fig. 1 is a perspective view showing an external appearance of a print head according to embodiment 1.

Fig. 2 is a partial sectional view showing the internal structure of the print head of embodiment 1.

Fig. 3 is a perspective view showing a state where a head cap is removed from the print head of embodiment 1.

Fig. 4 is a perspective view showing a head cover according to embodiment 1.

Fig. 5 is a perspective view showing an ink mist collecting member of example 1.

Fig. 6 is an external perspective view of the ink jet recording apparatus.

Fig. 7 is a perspective view showing a use state of the ink jet recording apparatus.

Fig. 8 is a conceptual diagram illustrating the operation principle of the inkjet recording apparatus.

Fig. 9 is a diagram illustrating an ink mist generation state when printing is performed by the inkjet recording apparatus.

Fig. 10 is a perspective view showing a forward deflection electrode of example 1.

Fig. 11 is a perspective view showing a modification of the positive deflection electrode of example 1.

Fig. 12 is a diagram showing an external appearance of a print head according to embodiment 2.

Fig. 13 is a partial sectional view showing the structure and the manner of use of a print head of embodiment 3.

Fig. 14 is a partial sectional view showing the structure of a print head of embodiment 4.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings.

Example 1

< structure of device appearance >

Fig. 6 is an external perspective view of an inkjet recording apparatus 400 according to example 1.

In fig. 6, 1 denotes an ink jet recording apparatus main body, 2 denotes a print head, 3 denotes an operation display unit, and 4 denotes a guide duct. The inkjet recording apparatus 400 includes an operation display unit 3 provided in an inkjet recording apparatus main body 1, a print head 2 provided outside the inkjet recording apparatus main body 1, and the print head 2 and the inkjet recording apparatus main body 1 are connected by a conduit 4.

< method of using device >

Next, the usage state of the inkjet recording apparatus 400 will be described with reference to fig. 7.

In fig. 7, 1 denotes an ink jet recording apparatus main body, 2 denotes a print head, 4 denotes a guide duct, 13 denotes a printing object for printing numerals and characters, 15 denotes a belt conveyor for conveying the printing object 13, 16 denotes a rotary encoder for measuring a conveying distance of the belt conveyor 15, and 17 denotes a print sensor.

The inkjet recording apparatus 400 is mounted on a production line in a factory for producing foods, beverages, or the like, for example, and the main body 1 is provided at a position operable by a user, and the print head 2 is provided at a position close to the print object 13 fed on the production line such as the belt conveyor 15.

In order to print in the same width regardless of the feeding speed in a production line such as a tape conveyor 15, a rotary encoder 16 that outputs a signal corresponding to the feeding speed to the inkjet recording apparatus, and a print sensor 17 that detects the printing object 13 and outputs a signal instructing the inkjet recording apparatus to print are provided, and these are connected to a control unit, not shown, in the main body 1.

The control unit controls the amount and time of charging of the ink particles 7C discharged from the nozzles 8 based on signals from the rotary encoder 16 and the print sensor 17, charges the printing object 13 while passing near the print head 2, and causes the deflected ink particles 7C to adhere to the printing object 13 to perform printing.

< principle of operation of device >

Next, the operation principle of the inkjet recording apparatus will be described with reference to fig. 8.

In fig. 8, 18 is a main ink tank, 7A is ink, 24 is a pump (for supply) that pressurizes and delivers ink, 9 is an electrostrictive element that vibrates at a predetermined frequency when a voltage is applied, 8 is a nozzle that discharges ink, and 7B is an ink column. Reference numeral 10 denotes a charging electrode for charging ink particles, 7C denotes ink particles, 11 denotes a grounded deflection electrode, 12 denotes a positive deflection electrode, 13 denotes a printing object to be printed, and 14 denotes a tank for collecting unprinted ink particles.

The ink 7A in the main ink tank 18 is sucked and pressurized by a pump (supply) 24 to be an ink column 7B and discharged from the nozzle 8. The nozzle 8 includes an electrostrictive element 9, and applies vibration to the ink at a predetermined frequency to granulate the ink column 7B discharged from the nozzle 8. The number of ink particles 7C thus generated is determined by the frequency of the excitation voltage applied to the electrostrictive element 9, and is the same as the frequency thereof. The ink particles 7C are given electric charges by applying a voltage of a magnitude corresponding to print information with the charging electrodes 10.

The ink particles 7C charged by the charging electrode 10 fly in the electric field between the ground deflection electrode 11 and the positive deflection electrode 12. The deflecting electric field is formed between a positive deflecting electrode 12 to which a high voltage of 1-7 kV is applied and a ground deflecting electrode 11 provided, and the charged ink particles 7C are deflected by a force proportional to the charge amount thereof, and fly and hit the printing object 13.

At this time, the hitting position of the ink particles 7C in the deflection direction changes according to the charge amount, and the printing object 13 is moved in the direction orthogonal to the deflection direction by the production line, so that the particles can be hit in the direction orthogonal to the deflection direction, and characters are formed by the plurality of hit ink particles 7D and printed. The ink particles 7C not used for printing fly linearly between the positive deflection electrodes 12, are captured by the tank 14, and are then sucked and collected by the pump (for collection) 25 into the main ink tank 18.

< printhead structure of embodiment 1 >

The structure of the print head 2 of the inkjet recording apparatus 400 according to embodiment 1 will be described with reference to fig. 1 to 5. In the drawings, fig. 1(a) shows an external perspective view of the print head 2 of the present embodiment, fig. 1(b) shows an external perspective view of the print head 2 with the collecting member holder 41 removed, fig. 2(a) shows a partial cross-sectional view of the print head 2 of the present embodiment, fig. 2(b) shows an enlarged view of a portion D of fig. 2(a), and fig. 3 shows a perspective view of the print head 2 with the head cap 60 of the present embodiment removed.

Fig. 4(a) is a perspective view of a head cover 60 of the present embodiment, fig. 4(b) is a perspective view of the head cover 60 at a changed angle so that the inside of the head cover 60 can be seen, fig. 5(a) is a perspective view of a collecting member holder 41 of the present embodiment, and fig. 5(b) is a perspective view of a state where the collecting member holder 41 is separated from a collecting member 42.

In fig. 1 to 3, the print head 2 includes: a nozzle 8 for discharging ink, a charging electrode 10 symmetrically arranged in parallel with the ink particles 7C discharged from the nozzle 8 as the center, a ground deflection electrode 11 and a positive deflection electrode 12 arranged in the flying direction of the ink particles 7C, and a groove 14 formed with a hole for catching the ink particles 7C unused in printing on the same axis as the ink particles 7C.

The nozzle 8, the charging electrode 10, the ground deflection electrode 11, the positive deflection electrode 12, and the groove 14 are provided in the head base 50. Further, a proximity sensor 71 that reacts when the magnet 61 is in the vicinity is incorporated in the head base 50. Further, an ink mist suction portion 51 is assembled to the head base 50.

The ink mist suction portion 51 is connected to the positive deflection electrode 12 via a connection portion 51A, which is the same member in this embodiment. Therefore, a high voltage of 1 to 7kV is applied to the ink mist suction part 51 in the same manner as the positive deflection electrode 12. In the present embodiment, the positive deflection electrode 12 and the ink mist suction portion 51 are described as being the same component and using the same power supply, but a configuration in which each is a different component and using a different power supply may be employed.

Next, in fig. 1 to 4, the print head 2 is assembled with a protective cover 70 for protecting the internal components of the print head 2, not shown. In the state where the protective cover 70 is assembled, the space surrounded by the head base 50 and the protective cover 70 can be protected from impacts and the like during maintenance. The member surrounded by the protective cover 70 is a region where a so-called service person performs maintenance. A head cover fixing screw 72 for fixing the head cover 60 is incorporated in the protective cover 70.

The head cap 60 is incorporated in the print head 2 to protect the nozzles 8, the charging electrodes 10, the ground deflection electrodes 11, the positive deflection electrodes 12, and the slots 14. The head cap 60 is made of stainless steel, and is electrically grounded when assembled to the print head 2. In the headcap 60, a slit 60A for passing ink particles 7C used for printing is formed in order to fit into a headcap fixing screw 72 of a protective cap 70. The headcap 60 is fixed to the head base 50 by a headcap fixing screw 72, and the headcap 60 is detachable from the print head 2 by loosening the headcap fixing screw 72.

The magnet 61 is incorporated in the head cover 60, and the proximity sensor 71 can determine whether or not the head cover 60 is incorporated at a proper position in response to the approach of the magnet 61. When the headcap 60 is detached from the print head 2, the high voltage (1 to 7kV) applied to the positive deflection electrode 12 and the ink mist suction part 51 is controlled to be OFF for safety.

The head cap 60 is assembled with an insulating cover 62 to prevent the ink mist suction portion 51 from being exposed to the outside of the print head 2. The insulating cover 62 protrudes from the head cover 60, and the ink mist suction portion 51 enters a recess inside the insulating cover 62. Thus, the front end of the ink mist suction part 51 is positioned near the outer wall of the head cap 60 or protrudes outward from the outer wall, and the electric field generated by the ink mist suction part 51 affects the outside of the print head 2.

The ink mist suction portion 51 is configured to be in non-contact with the concave portion inside the insulating cover 62 and to improve insulation by separating a certain space. The insulating cover 62 is made of a fluorine resin (e.g., PTFE) to improve water repellency.

Accordingly, even when used in a high-humidity environment, the surface of the insulating cover 62 is less likely to be connected by condensate, and the insulating properties can be maintained. The insulating cover 62 is made of a resin such as polyphenylene sulfide (PPS) or polybutylene terephthalate (PBT), and when a surface treatment such as coating the surface with a fluorine-based resin is performed, the same effect as when the fluorine-based resin is used as the material can be obtained.

In fig. 1 to 5, the nose cap 60 fixes the collecting member holder 41 by using the collecting member holder fixing screw 73. The collecting member holder 41 is formed with a fixing portion 41B having a notch formed so as to fit into the collecting member holder fixing screw 73, a slit 41A for passing the ink particles 7C used for printing, and a recess portion 41C having a notch formed so as to fit into the projection of the insulating cover 62. The slit 41A is assembled to reach the same position as the slit 60A of the head cover 60.

Also, the collecting member holder 41 can fix the collecting member 42 outside the traveling direction of the ink particles 7C. The collecting member 42 is formed with slits 42A for passing the ink particles 7C used in printing, like the headcap 60 and the collecting member holder 41. The collecting member 42 is assembled to the collecting member holder 41 so that the slit 42A of the collecting member 42 reaches the same position as the slit 41A of the collecting member holder 41.

One surface of the collecting member 42 is a sticker coated with paste, and the sticker is fixed by attaching the paste to the collecting member holder 41. The collecting member 42 is not limited to a sticker, and the collecting member 42 may be fixed to the collecting member holder 41 by insertion, screwing, or the like. The material of the collecting member 42 is not particularly limited as long as it is a material to which ink is applied, such as paper, a resin plate, or metal.

< Structure of ink mist suction part of embodiment 1 >

The configuration of the ink mist suction portion 51 and the positive deflection electrode 12 in embodiment 1 will be described with reference to fig. 10. In fig. 10, the positive deflection electrode 12 is provided with a connection portion 51A at a portion that does not affect a deflection electric field for deflecting the ink particles 7C formed together with the ground deflection electrode 11 in a state of being assembled to the print head 2. The connection portion 51A is connected to the ink mist suction portion 51. The ink mist suction portion 51 protrudes toward the groove 14 side from the tip of the positive deflection electrode 12 in a state of being assembled to the print head 2. Thereby, an electric field for collecting the ink mist 31 can be further formed outside the print head 2.

The ink mist suction portion 51 may be covered with an insulator in a range of E indicated by an ellipse of a dotted line in fig. 10. For example, the ink mist suction part 51 is coated with an insulator on its surface. For example, the ink mist suction part 51 is coated with a fluororesin and dried, or the ink mist suction part 51 is formed by injection molding a thermoplastic-filled insulator around the ink mist suction part, and then cooling and solidifying the insulator.

With this configuration, since a part of the vicinity of the tip of the ink mist suction part 51 is close to the head cap 60, the electric field between them becomes large, and particularly in the case where an electric field having a magnitude exceeding the dielectric strength of air is generated in the vicinity of the surface of the ink mist suction part 51 having the highest electric field, the generation of corona discharge can be suppressed by replacing the air in the vicinity of the surface with an insulator. Thus, for example, even if the insulating cover 62 is eliminated, there is no fear that the high-voltage portion is exposed to the outside of the print head 2 and gets an electric shock.

The front end of the positive deflection electrode 12 may be extended in the ink discharge direction of the nozzle 8 to a concave portion of the insulating cover 62, and the ink mist suction portion 51 may be formed by this portion.

A modification of the ink mist suction portion 51 will be described with reference to fig. 11. In fig. 11, the positive deflection electrode 12 is connected to the ink mist suction portion 52 via a connection portion 52A. The ink mist suction portion 52 includes a cut-out opening portion 52B. When a part of the floating ink mist 31 enters the inside of the print head 2, the ink mist 31 may adhere to the ink mist suction portion 52 due to the influence of the electric field, but the provision of the opening 52B prevents the ink mist 31 from being concentrated and accumulated in one place, and prevents the deflection electric field affecting the ink particles 7C.

Action of embodiment 1

A usage of the inkjet recording apparatus 400 according to embodiment 1 will be described with reference to fig. 9. Fig. 9 is a diagram showing an ink mist generation state when printing is performed by the ink jet recording apparatus 400, and shows a state where printing is performed on the surface of the object to be printed 13 by the ink jet recording apparatus. By conveying the object 13 in the B direction at a position facing the fixed head 2, characters, symbols, and the like are printed on the upper side of the object 13.

At this time, depending on the speed of the ink particles discharged from the slit 60A of the print head 2 and the distance between the print head 2 and the surface of the object to be printed 13, a part of the hit ink particles 7D hitting the object to be printed 13 may bounce back. The rebounded ink is atomized, and an ink mist 31 as floating ink is generated. Regarding the amount of the ink mist 31, as the interval between the hitting ink particles 7D becomes narrower, the hitting ink particles 7D hit so as to overlap each other before they dry, and the amount of ink rebounding becomes larger, and therefore the amount of the ink mist 31 generated becomes larger.

When the distance between the print head 2 and the print object 13 is short, the ink mist 31 charged in the print head 2 is likely to adhere to the collecting member 42 held by the print head 2 due to the influence of the air flow when the ink rebounds and the influence of the electric field formed by the ink mist suction portion 51. On the surface of the collecting member 42, the attached contamination occurs due to the ink mist 31 rebounded from the hit ink particles 7D, but the contamination exists being biased toward the conveying direction side of the printing object 13. With such a configuration, the print head 2 can be prevented from being contaminated by the floating ink mist 31 or the contamination can be reduced.

The collecting member 42 used in the present embodiment is gradually contaminated with ink by catching the ink mist 31, and therefore, needs to be replaced or cleaned periodically. The collecting member 42 to which the ink mist 31 has adhered can be replaced with a new collecting member 42 by removing the collecting member holder 41 from the print head 2 by loosening the collecting member holder fixing screw 73, and removing the collecting member 42 as a sticker from the collecting member holder 41 in this state. Then, by fixing the collecting member holder 41, on which the new collecting member 42 is mounted, to the print head 2, it is still possible to reduce the contamination of the print head 2 with the ink mist 31.

< Effect of example 1 >

As described above, according to the present embodiment, by causing the floating ink mist 31 to adhere to the collecting member 42, contamination of the inside and outside of the print head 2 with ink can be suppressed. Further, the structure for collecting the ink mist 31 is a structure that can be provided integrally with the print head 2, and thus, a small and small installation space can be realized. Further, the ink jet recording apparatus 400 can be provided in which the collecting member 42 that needs to be replaced regularly can be replaced easily.

Example 2

The invention of example 2 will be described below with reference to the drawings. Note that the same portions as those in embodiment 1 are not described, and portions different from those in embodiment 1 are mainly described.

< printhead structure of embodiment 2 >

An embodiment of an inkjet recording apparatus 400 according to example 2 of the present invention will be described with reference to fig. 12. In the drawings, fig. 12(a) shows an external perspective view of the print head 2A of the present embodiment, fig. 12(b) shows a front view of the print head 2A of the present embodiment, and fig. 12(c) shows a side view of the print head 2A of the present embodiment.

In fig. 12, an elongated collecting member holder 44 is fixed to the head cap 60 using a collecting member holder fixing screw 73. The elongated collecting member holder 44 is formed with: a plurality of fixing portions 44B having notches formed so as to fit into the collecting member holder fixing screws 73, slits 44A for passing ink particles 7C used for printing, and recesses 44C having notches formed so as to fit into the projections of the insulating cover 62. The slit 44A is assembled in such a manner as to reach the same position as the slit 60A of the head cover 60. The extended collecting member holder 44 includes a positioning portion 44D for pressing the side surface of the head cap 60 to fix the angle in order to stabilize the fixed position.

Action of embodiment 2

The extended collecting member holder 44 used in the present embodiment can adjust the distance between the object to be printed 13 and the extended collecting member holder 44 over a plurality of positioning portions by detaching the extended collecting member holder 44 from the print head 2 by loosening the collecting member holder fixing screw 73 and changing the position to another positioning portion 44D. Since the closer the distance between the object to be printed 13 and the extended collecting member holder 44 is, the more ink mist 31 can adhere to the extended collecting member holder 44, the contamination of the periphery of the print head 2A by the ink mist 31 can be reduced.

Contamination by the ink mist 31 adhering to the extended collecting member holder 44 can be easily cleaned with a solvent such as Methyl Ethyl Ketone (MEK) or ethanol, and therefore, the same member can be used many times.

In addition, the following method can be adopted for the extended collecting member holder 44 as in example 1: by attaching the collecting member 42 to the extended collecting member holder 44, the ink mist 31 can be adsorbed by the collecting member 42, and by periodically replacing the collecting member 42 contaminated with the ink mist 31, contamination by the ink mist 31 in the print head 2A and the periphery can be reduced.

< Effect of example 2 >

According to the present embodiment, in addition to the effects of embodiment 1, it is possible to provide the ink jet recording apparatus 400 that can further reduce contamination of the print head 2A by the ink mist 31 and contamination of peripheral devices by adjusting the distances of the extended collecting member holder 44 and the collecting member 42 attached to the print head 2A from the object to be printed 13 across a plurality of positioning portions.

Example 3

The invention of example 3 will be described below with reference to the drawings. Note that the description of the same portions as those in embodiments 1 and 2 is omitted, and the description will be mainly given of portions different from those in embodiments 1 and 2.

< printhead structure of embodiment 3 >

An embodiment of an inkjet recording apparatus 400 according to example 3 of the present invention will be described with reference to fig. 13. Fig. 13 is a partial sectional view showing a structure and a use mode of a print head according to embodiment 3.

In fig. 13, the print head 2B includes a headcap 64, a tapered collecting member holder a46 fixed to the headcap 64 using a headcap fixing screw 72, and a collecting member 47 fixed to a tapered collecting member holder a 46. The head cover 64 is formed with: a slit 64A through which ink particles 7C for printing pass; a tapered B portion 64C connected to the head base 50 at a surface crossing at right angles the direction of deflection of the ink particles 7C used for printing and inclined in a direction to reduce the space inside the print head 2B; connected to the tapered a portion 64B in the opposite direction to the head base 50.

Further, the tapered collecting member holder a46 is formed with: a slit 46A through which ink particles 7C used for printing pass, a tapered D portion 46C that fits into a tapered B portion 64C of the headcap 64 on a surface that intersects at right angles with the direction of deflection of the ink particles 7C used for printing, and a tapered C portion 46B that fits into a tapered a portion 64B of the headcap 64.

The collecting member 47 is made of a material such as a sticker, and is assembled in accordance with the shape of the slit 46A, the taper C portion 46B, and the taper D portion 46C of the taper collecting member holder a 46. Therefore, in the present embodiment, the passing position of the ink particles 7C for printing by the print head 2B becomes the position closest to the printing object 13.

Action of embodiment 3

Next, the usage and operation of the print head 2B will be described. In fig. 13, the belt conveyor 15 carrying the printing object 13 flows in the direction of the arrow of the conveyor flow direction 101. Thereby, the printing object 13 flows in the direction of the printing object moving direction 102. Therefore, the air flow 103 is generated around the print head 2B by the movement of the belt conveyor 15 and the print object 13.

The air flow 103 serves as a flow for reducing the intrusion of the ink mist 31 into the print head 2B, and therefore, the ink contamination of the print head 2B can be reduced.

< Effect of example 3 >

According to the present embodiment, in addition to the effects of embodiment 1, it is possible to provide the inkjet recording apparatus 400 in which the air flow 103 generated by the flow of the object to be printed 13 can reduce ink contamination of the print head 2B by the ink mist 31 by providing the tapered portion in the shape of the headcap 64, the tapered collecting member holder a46, and the collecting member 47 attached to the print head 2B.

Example 4

The invention of example 4 will be described below with reference to the drawings. Note that the same portions as those in embodiments 1 to 3 are not described, and the portions different from those in embodiments 1 to 3 are mainly described.

< printhead structure of embodiment 4 >

An embodiment of an inkjet recording apparatus 400 according to example 4 of the present invention will be described with reference to fig. 14. Fig. 14 is a partial sectional view showing the structure of a print head in embodiment 4.

In fig. 14, the print head 2C includes: a head cap 66, a tapered collecting member holder B fixed to the head cap 66, and a collecting member 49 fixed to the tapered collecting member holder B. The head cap 66 is formed with: a slit 66A through which ink particles 7C used in printing pass; a tapered F portion 66C connected obliquely to the ground deflection electrode 11 side so as to reduce the space inside the print head 2B; the tapered E portion 66B on the positive deflection electrode 12 side is obliquely connected so as to reduce the space inside the print head 2B.

Further, the tapered collecting member holder B is formed with: a slit 48A through which ink particles 7C used for printing pass, a tapered H portion 48C that fits into a tapered F portion 66C of the headcap 66 on the ground deflection electrode 11 side, and a tapered G portion 48B that fits into a tapered E portion 66B of the headcap 66 on the positive deflection electrode 12 side. The collecting member 49 has a slit 49A formed therein, is made of a material such as a sticker, and is assembled in accordance with the shapes of the slit 48A, the taper G portion 48B, and the taper H portion 48C of the taper collecting member holder B. Therefore, in the present embodiment, the passing position of the ink particles 7C for printing by the print head 2C becomes the position closest to the printing object 13.

In addition, the print head 2C includes an ink mist suction portion 54. The ink mist suction portion 54 has a front end portion 54B housed in the head cap 66 and a connection portion 54A for connecting to the positive deflection electrode 12. The front end 54B of the ink mist suction portion 54 projects in the groove 14 direction from the front end of the positive deflection electrode 12.

Action of embodiment 4

In the print head 2C, the ink mist 31 may intrude into the head cap 66 through the slit 66A. Inside the head cap 66, there are the ground deflection electrode 11, the positive deflection electrode 12, and the ink mist suction portion 54, and there is an electrostatic field formed by them. The charged ink mist 31 is attracted to the ink mist attracting portion 54, and therefore, it is possible to prevent the ink particles 7C for printing from being caught and accumulated at the tip portion of the positive deflection electrode 12 and the like to interfere with the flight of the ink particles 7C.

Further, by making the groove 14 side of the print head 2C tapered, it is possible to further approach the object to be printed 13, and it is possible to improve the print quality and print small characters.

< Effect of example 4 >

According to the present embodiment, in addition to the effects of embodiments 1 to 3, the ink mist suction unit 54 is attached to the inside of the print head 2C, so that the front end of the print head 2C can be made smaller, and the print head 2C can be brought closer to the object to be printed 13.

The present invention is not limited to the above-described embodiments, and includes various modifications. The above-described embodiments are described in detail to explain the present invention easily and understandably, and are not limited to all the configurations which are necessarily included in the description.

Description of the reference numerals

1 … … main body, 2 … … print head, 41 … … collecting member holder, 42 … … collecting member, 44 … … extension collecting member holder, 46 … … taper collecting member holder a, 51 … … ink mist suction part, 51a … … connecting part, 400 … … ink jet recording apparatus.

Claims

1. An inkjet recording apparatus, comprising: a nozzle for forming ink particles; a charging electrode for charging the ink particles; a deflection electrode for deflecting the charged ink particles; a groove formed with a hole for catching the ink particles unused in printing coaxially with the ink particles; and a print head capable of discharging the deflected ink particles to print an object to be printed,

the inkjet recording apparatus is characterized in that:

a collecting member that collects the floating ink is disposed between the print head and the printing object, and,

the collecting member has an opening portion for passing the ink particles discharged from the print head,

the deflection electrodes include a ground deflection electrode and a positive deflection electrode arranged in a flight direction of the ink particles,

an ink mist suction portion that sucks the floating ink and is connected to the positive deflection electrode via a connection portion is provided in the print head,

the ink mist suction part is in a state of protruding to the groove side than the front end of the positive deflection electrode in a state of being assembled to the print head,

the ink mist suction portion is covered by an insulating cover near a front end portion of the print head.

2. The inkjet recording apparatus according to claim 1, characterized in that:

the collecting member supporting portion supporting the collecting member can be detached from the print head, and the distance between the collecting member supporting portion and the print object can be adjusted.

3. The inkjet recording apparatus according to claim 1, characterized in that:

the collecting member is a sticker that can be replaced by being attached to a collecting member support portion supporting the collecting member.

4. The inkjet recording apparatus according to claim 1, characterized in that:

the collecting member supporting portion that supports the collecting member has a tapered shape, and the collecting member supporting portion is configured so that a periphery of an opening hole of the print head that discharges the ink particles is closest to the print object.

5. The inkjet recording apparatus according to claim 1, characterized in that:

the collecting member and the collecting member supporting portion supporting the collecting member have a tapered shape.

6. The inkjet recording apparatus according to claim 1, characterized in that:

the ink mist suction portion has an opening.

7. The inkjet recording apparatus according to claim 1, characterized in that:

the ink mist suction part is not in contact with the insulating cover.

8. The inkjet recording apparatus according to claim 1, characterized in that:

the surface of the insulating cover is covered with a fluorine-based resin for improving water repellency.