JP2007152903A - Inkjet print head cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix ink near a suction port, and there is a possibility that ink cannot be sufficiently sucked from the suction port by a suction operation of a recovery device.
In order to solve the above problems, a suction port using capillary force is obtained by using a cap having a notch having an inclined surface on the bottom surface and the notch communicating with the suction port on the bottom surface. To prevent ink sticking near the suction port.
[Selection] Figure 1

Description

  The present invention relates to an inkjet printing apparatus, and more particularly to an improvement of a recovery apparatus for recovering or maintaining good ink ejection performance of an inkjet print head.

  2. Description of the Related Art Conventionally, printing apparatuses that perform printing on printing media (hereinafter, also simply referred to as “recording paper”) such as paper, cloth, plastic sheets, and OHP sheets have various printing methods such as wire dot methods, thermal methods, It has been proposed as a form capable of mounting a print head by a thermal transfer method or an ink jet method.

  Among such printing apparatuses, an inkjet printing type printing apparatus (hereinafter also referred to as an inkjet printing apparatus) that prints on recording paper by ejecting ink from ejection ports (nozzles) is a low-noise non-impact type printing. This is a method that enables high-density and high-speed printing operations.

  In general, an ink jet printing apparatus includes means for driving a carrier on which a print head is mounted, transport means for transporting recording paper, and control means for controlling them.

  On the other hand, as an energy generating element that generates energy used to eject ink from the ejection port of the print head, an element using an electromechanical transducer such as a piezo element, or an electromagnetic wave such as a laser is irradiated to generate heat. In addition, there are those that discharge ink droplets by the action of heat generation, and those that heat a liquid by an electrothermal transducer element having a heating resistor.

  Among them, an ink jet print type print head that uses thermal energy to eject ink as droplets can perform high-resolution printing because the discharge ports can be arranged at high density. Among them, print heads that use electrothermal transducer elements as energy generation elements are easy to downsize, and have the advantages of IC technology and micro processing technology that have made remarkable progress in technology and improved reliability in the recent semiconductor field. It is advantageous because it can be fully utilized for manufacturing, easy to mount with high density, and inexpensive to manufacture.

  As described above, the ink jet printing method has a simple configuration, and an excellent printing method generally includes a recovery processing device that removes thickened ink and dust adhering to the ejection port forming surface of the recording head, and is stable. The ink ejection function is maintained. The recovery processing apparatus includes, for example, one or a plurality of cap members that cover a discharge port forming surface of a recording head during non-recording, and a cap member in order to prevent drying and evaporation of ink as a recording liquid. And a pump for sucking thickened ink or the like from the discharge port forming surface of the recording head and the vicinity thereof.

  An ink jet recording apparatus that performs an ink suction operation by bringing a cap member into close contact with a conventional recording head is described in Patent Document 1.

In the ink suction operation described in this publication, the cap member is brought into close contact with the ejection nozzle forming surface of the recording head, the inside of the cap member is made negative pressure, the ink in the recording head is sucked through the nozzle, and then the cap member This comprises a step of making the inside communicate with the atmosphere and pulling the cap member away from the recording head. Specifically, the cap 103 in FIG. 5 is brought into close contact with the recording head 101, the air release valve 104 is closed, the inside of the cap 103 member is made negative using the pump 102 from the suction port 106, and the ink in the head is sucked. Next, in order to make the inside of the cap member communicate with the atmosphere, the atmosphere opening 104 is opened and the cap 103 is pulled apart.
Japanese Patent Publication No. 03-61593

  However, in recent years, the types of black ink and color ink have been changed from the viewpoints of black printing color development and color printing color reproducibility, that is, black ink uses pigment-based ink and color ink uses dye-based ink. It is becoming. In particular, as time elapses, the pigment ink starts to adhere so as to block the vicinity of the cap absorber 107 in contact with the air release valve port 104 and the suction port 106 in FIG. If such a state further progresses, there is a possibility that the suction operation of the recovery device cannot sufficiently suck ink from the suction port.

  Accordingly, in order to solve the above-described problem, an inkjet print cap used for capping the surface on which the ink discharge port of the inkjet print head is disposed, and a mark is formed on the bottom surface of the cap that faces the surface. An ink jet print head cap is provided, wherein the notch is present on at least a part of the bottom surface of the cap, and the notch has an inclined surface.

  In addition, there is a pump for sucking ink from an inkjet discharge port, the pump and the cap are connected through the suction port, and the suction port and the notch according to claim 1 communicate with each other. A cap for an inkjet head characterized by the above is proposed.

  According to the present invention, by providing a notch on the bottom surface of the cap, it is possible to reduce the amount of ink remaining in the cap as much as possible and prevent the ink in the cap from sticking.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

(Outline of the device)
FIG. 2 is a schematic perspective view showing an example of the overall configuration of an inkjet printing apparatus according to an embodiment of the present invention. This is an ink jet printing apparatus that discharges ink from the print head 3 and prints on the print paper P. The print head 3 is mounted on a carrier, and the carrier 2 is supported by a guide shaft 7 and a guide rail 8 that are fixed at both ends of the frame 6 and arranged parallel to each other so as to be slidable in the axial direction. Yes. The carrier 2 is reciprocated by a belt drive device (not shown) and a rotational drive source such as a stepping motor. The print paper P is nipped and conveyed by the conveyance roller 9 and the pinch roller 5 that is in contact therewith. The ink tank 4 and the print head 3 supply ink through the supply tube 20.

  Reference numeral 14 denotes a recovery device, which is an operation (capping, suction, wiping) for recovering the performance of the inkjet print head or holding it in a good state at the time of waiting for a print command, before or after the print operation, or at an appropriate timing during the print operation. Etc.).

  In this example, an electrothermal converter that generates thermal energy as energy used for ink ejection is provided, and the state of the ink accompanying film boiling is caused by the generation of thermal energy in response to energization. In this case, the ink discharge mode is used. In addition, the print heads can be provided in a number corresponding to inks having different colors and densities (hereinafter referred to as color tones). It may have a discharge part. Furthermore, as the discharge unit, a plurality of discharge ports may be arranged in an appropriate direction.

(Configuration and operation of recovery device)
Next, the suction operation of the recovery device 14 will be described in detail with reference to FIG. FIG. 3 is a schematic cross-sectional view showing a configuration example of a cap, an in-cap absorber, a pump, and the like provided in the recovery device of the present example and a suction operation.

  3, a plurality of ink discharge ports 22 are opened on the discharge port surface of FIG. The ink discharge port surface 22 is capped with a cap 18, and an in-cap absorber 19 is installed in the cap. Two types of tubes are connected to the cap, one is a pump tube 15 and the other is an air release valve 16.

  In the suction operation, first, the air release valve 23 is closed, and the inside of the supply tube 20, the ink discharge port surface 22, and the cap 18 is set to a negative pressure by using a pump. Then, the ink is supplied to the ink discharge port through the tube 20. After supplying ink to the ink discharge port, the air release valve 23 is opened to return the inside of the cap to atmospheric pressure.

(cap)
The cap 18 will be described with reference to FIG. In FIG. 1, an in-cap absorber 19 exists in the cap 18, and two ports are provided on the bottom surface of the cap 18. When the ink is sucked from the ink discharge port surface 22 shown in FIG. 3 using the pump 21, the supply tubes 20 of the respective colors have different flow path resistances, and the ink is released when the atmosphere is released during the suction operation. There is a risk of backflow from a tube having a high flow resistance to a tube having a low flow resistance. Therefore, the in-cap absorber 19 is used in order to prevent the backflow phenomenon as much as possible. One of the two ports provided on the bottom surface of the cap is a suction port 15 that sucks ink using the pump 21 of FIG. The other is an opening that opens the air release valve 23 in order to return the state in which the inside of the cap is maintained at a negative pressure to the atmosphere after the suction operation.

  The ink flow in the cap 18 will be described in detail with reference to FIG. In the cap 18, ink is sucked from the suction port 15 through the in-cap absorber 19 from the print head 3 during the suction operation. The ease of ink flow at this time is indicated by the size of the arrow in FIG. Conventionally, as shown in FIG. 4B, the suction amount is different between the portion A farthest from the suction port and the portion B close to the suction port. Further, since the distance from the ink ejection surface B to the suction port is long, the ink remains on the absorbent body in the cap and may adhere to the absorbent body. Therefore, in the present invention, by installing the notch 17 of FIG. 1 directly below the pigment ink nozzle, it is possible to uniformly suck in the pigment ink which is difficult to flow. Specifically, as shown in FIG. 4A, the suction port is widened by connecting the notch 17 and the suction port 15, and the entire bottom surface of the in-cap absorber 19 is sucked as uniformly as possible. By sucking uniformly, the suction amount can be made the same as much as possible at the point A farthest from the suction port and the point B near the suction port, and the amount of ink remaining on the absorber in the cap is small. Therefore, it also prevents sticking.

  By using this notch on the surface facing the ink discharge port, where pigment and other inks are more difficult to flow, cap the difference in viscosity between the pigment ink and the dye ink even when sucking the cap that uses pigment and dye simultaneously. Can be absorbed by the inner structure.

It is the top view and sectional drawing which show the schematic structural example in the cap of this invention. It is a schematic sectional drawing which shows the structural example of the recovery apparatus applicable to the apparatus of FIG. The schematic sectional drawing which shows the structural examples and suction operation | movement of a cap, the absorber in a cap, a pump, etc. which were provided in the recovery apparatus. (A) The cap sectional view which showed the ink suction amount at the time of providing a notch, (b) The cap sectional view which showed the conventional ink suction amount. The schematic sectional drawing which shows the structural example and suction operation | movement of a cap, the absorber in a cap, a pump, etc. which were provided in the recovery apparatus conventionally.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printing apparatus 2 Carrier 3 Print head 4 Ink tank 5 Pinch roller 7 Guide shaft 8 Guide rail 9 Conveying roller 14 Recovery device 15 Suction port 16 Atmospheric release valve port 17 Scraping 18 Cap 19 Absorber in cap 20 Supply tube 21 Pump 22 Ink discharge port surface 23 Air release valve 24 Ink flow
101 print head
102 pump
103 cap
104 Air communication port
105 Air release valve
106 Suction port
107 Absorber in cap

Claims (2)

  An ink-jet print cap used for capping a surface on which an ink discharge port of an ink-jet print head is disposed, having a notch on the bottom surface of the cap facing the surface, and the notch is formed on the bottom surface of the cap. An ink jet print head cap which is present at least in part and has an inclined surface at the notch.   A pump for sucking ink from an ink jet discharge port exists, the pump and the cap are connected through the suction port, and the suction port and the notch according to claim 1 communicate with each other. An inkjet head cap.

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