JP2010269513A - Fluid ejection device - Google Patents

Abstract

A fluid ejecting apparatus capable of reliably sealing nozzles while reducing the size of a recording head.
An ink jet printer according to the present invention includes a recording head having a nozzle surface having a nozzle row formed of a plurality of nozzle openings and a nozzle head that extends along the nozzle row and belongs to the nozzle row. An elastic member 45 that can seal a plurality of nozzle openings 17 and is movable relative to the recording head 5, and a pressure detection device 10 that detects a sealing state of the nozzle openings 17 by the elastic member 45. ing.
[Selection] Figure 2

Description

  The present invention relates to a fluid ejecting apparatus.

  An ink jet printer (hereinafter referred to as “printer”), which is a type of fluid ejecting apparatus, applies ink (fluid) to a recording medium such as printing paper from nozzles formed on the nozzle surface of a recording head (fluid ejecting head). Printing is performed by spraying.

  In the recording head, the moisture of the ink easily evaporates from the nozzle opening (hereinafter referred to as the nozzle opening), so that the viscosity of the ink in the nozzle rises and the nozzle is easily clogged. For this reason, when the printer is stopped, the cap member is brought into close contact with the recording head to seal the nozzle surface, thereby suppressing water evaporation of ink from the nozzle opening (for example, Patent Document 1). .

JP 2004-216913 A

  However, when the configuration of the recording head is complicated and the seal range (portion where the cap member abuts) cannot be secured within the nozzle surface, the nozzle surface cannot be sealed by the cap member. In addition, the fact that the sealing range with which the cap member abuts must be secured, which hinders the promotion of downsizing of the recording head.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a fluid ejecting apparatus capable of reliably sealing nozzle openings while reducing the size of a recording head. One of them.

  In order to solve the above problems, a fluid ejecting apparatus of the present invention has a fluid ejecting head having a nozzle surface on which a nozzle array composed of a plurality of nozzle openings is formed, and extends along the nozzle array and the nozzle array An elastic member capable of sealing the plurality of nozzle openings belonging to the above, and movable relative to the fluid ejecting head; and a detection device that detects a sealing state of the nozzle openings by the elastic member. It is characterized by that.

  According to the present invention, since the nozzle opening of the fluid ejecting head can be directly sealed by the elastic member that can move relative to the fluid ejecting head, the nozzle opening can be reliably sealed. At the same time, it is not necessary to seal the entire nozzle surface of the recording head with the cap member as in the prior art. For this reason, since it is not necessary to ensure the sealing range for making the cap member contact | abutted conventionally required in a nozzle surface, the further size reduction of a fluid ejecting head is accelerated | stimulated.

Further, it is preferable that the detection device detects a pressure of ink in the fluid ejecting head.
According to the present invention, it is possible to accurately confirm whether or not the nozzle opening is sealed by detecting the pressure in the fluid ejecting head. For example, it can be considered that the nozzle opening is sealed when the pressure of the fluid ejecting head is increased, and is not sealed when the pressure does not increase. In addition, the nozzle opening can be reliably sealed based on the pressure detected by the detection device.

In addition, it is preferable that the elastic member has a curved shape in which a distal end protrudes outward.
According to the present invention, since the tip of the elastic member has a curved shape protruding outward, the stress at the time of sealing can be increased.

The elastic member is preferably slidable on the nozzle surface.
According to the present invention, it is possible to provide the elastic member with a wiper function for removing fluid adhering to the nozzle surface (near the nozzle opening).

In addition, it is preferable that a plurality of the elastic members are provided that have a plurality of the nozzle rows and are arranged corresponding to the pitch of the plurality of nozzle rows.
According to the present invention, sealing with an elastic member can be reliably performed for each nozzle row.

Moreover, it is preferable that the said elastic member opposes the said some nozzle row.
According to the present invention, it is possible to seal a plurality of nozzle rows with one elastic member, and the alignment of the elastic member with respect to each nozzle row is facilitated.

1 is a block diagram showing an electrical configuration of an ink jet printer according to an embodiment. 1 is a schematic diagram illustrating a schematic configuration of an inkjet printer according to an embodiment. FIG. 2 is a partial cross-sectional view illustrating an internal configuration of a recording head according to an embodiment. The top view which shows the arrangement state of the nozzle in the nozzle surface of this embodiment. Explanatory drawing which shows the sealing operation by the sealing mechanism of this embodiment. The flowchart figure which shows operation | movement of a sealing mechanism. 6 is a graph showing a pressure change in the recording head before and after sealing. Explanatory drawing which shows the wiping operation | movement by the sealing mechanism of this embodiment. 6 is a graph showing a pressure change in the recording head after sealing.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

(First embodiment)
FIG. 1 is a block diagram illustrating an electrical configuration of an ink jet printer (ink jet printer) as an embodiment of a fluid ejecting apparatus. FIG. 2 is a schematic diagram illustrating a schematic configuration of the ink jet printer.

  The ink jet printer 1 performs a recording process for printing predetermined information or an image by ejecting ink (fluid) onto a recording sheet. As shown in FIGS. 1 and 2, the control device controls the overall operation. 2, an input device 3, a storage device 4, a recording head (fluid ejecting head) 5, a recording paper transport mechanism 9, a pressure detection device 10, a sealing mechanism 11, and the like.

  The control device 2 electrically controls the operation of various components, and includes an input device 3, a storage device 4, a recording head 5, a recording paper transport mechanism 9, a pressure detection device 10, a sealing mechanism 11, and the like. And various input / output interface circuits for exchanging data, and a CPU for performing predetermined arithmetic processing based on the data.

  The input device 3 inputs various commands and data related to recording processing from the outside to the control device 2, and includes an operation panel operated by a user, a communication device for inputting print data and the like from the outside.

  The storage device 4 stores operation programs for various components related to recording processing and data input from the input device 3.

  The recording head 5 includes a piezoelectric element 6 and a drive signal generator 7 that generates a drive signal input to the piezoelectric element 6, and ejects ink based on the drive signal input to the piezoelectric element 6.

  The pressure detection device 10 detects the pressure in the recording head 5 and is electrically connected to the sealing mechanism 11 via the control device 2. The pressure detection device 10 is disposed on the ink flow path 47 that connects the ink tank 42 and the print head 5 on the upstream side of the print head 5, and the pressure of the pressurized ink conveyed in the ink flow path 47 is measured. It is detected as the pressure of ink in the recording head 5. The pressure detection device 10 is disposed on the downstream side of the supply pump 43 for conveying the ink in the ink flow path 47.

  The sealing mechanism 11 includes a sealing unit moving unit 12 that moves a sealing unit 41 (described later) relative to the recording head 5. The sealing portion moving means 12 changes the position of the sealing portion 41 based on the detection signal output from the pressure detection device 10.

Here, the configuration of the recording head will be described with reference to FIGS.
FIG. 3 is a partial cross-sectional view showing an internal configuration of the recording head, and FIG. 4 is a plan view showing an arrangement state of nozzles on the nozzle surface.

  As shown in FIG. 3, the recording head 5 includes a head main body 18 and a flow path forming unit 22 connected to the head main body 18. The flow path forming unit 22 includes a vibration plate 19, a flow path substrate 20, and a nozzle substrate 21, and includes a common ink chamber 29, an ink supply port 30, and a pressure chamber 31 formed by these. Yes.

  Further, the flow path forming unit 22 includes an island portion 32 that functions as a diaphragm portion, and a compliance portion 33 that absorbs pressure fluctuation in the common ink chamber 29. The head main body 18 is formed with an accommodation space 23 for accommodating the drive unit 24 together with the fixing member 26, and an internal flow path 28 for guiding the ink supplied from the ink tank 42 shown in FIG. ing.

  As shown in FIG. 4, a plurality of nozzle openings 17 are provided along the long side direction (recording paper width direction) on the nozzle surface 5 </ b> A to form a nozzle row 16. The nozzle rows 16 are provided in a plurality of rows along the short side (recording paper conveyance direction), and in this embodiment, there are four rows. The nozzle rows 16Y, 16M, 16C, and 16Bk are configured to eject ink corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (Bk), respectively.

  According to the recording head 5 having the above-described configuration, when a drive signal is input to the drive unit 24 via the cable 27, the piezoelectric element 6 expands and contracts and the diaphragm 19 is deformed (moved) toward and away from the cavity. ) For this reason, the volume of the pressure chamber 31 changes and the pressure of the pressure chamber 31 containing ink fluctuates. The ink is ejected from the nozzle opening 17 due to the fluctuation of the pressure.

Next, the configuration of the sealing mechanism 11 will be described in detail.
Returning to FIG. 2, the sealing mechanism 11 of the present embodiment is for sealing the nozzle row 16 of the recording head 5 during non-printing, and is a sealing portion that can move relative to the recording head 5. 41 and a sealing part moving means 12 for realizing the movement of the sealing part 41.

  The sealing portion 41 includes a base 44 facing the nozzle surface 5 </ b> A of the recording head 5 and a plurality of elastic members 45 provided on the base 44. The sealing portion 41 is disposed below the recording head 5, and the position with respect to the recording head 5 is changed by the sealing portion moving means 12.

The elastic member 45 extends along the nozzle row 16 of the recording head 5 and is formed using an elastic material having high liquid repellency with respect to ink. The hardness of the elastic material used is about 50 °.
The width W (thickness) of the elastic member 45 is preferably equal to or larger than the diameter (about 0.025 mm) of the nozzle opening 17. In this embodiment, specifically, it is about 1.5 mm. Since the plurality of elastic members 45 are arranged corresponding to the pitch of the nozzle rows 16, the respective nozzle openings 17 belonging to the corresponding nozzle rows 16 can be sealed by the respective elastic members 45. .

  Since the elastic member 45 of the present embodiment has a curved surface shape with the tip 45A protruding outward, the elastic member 45 is easily deformed by the pressing force when contacting the nozzle surface 5A. For this reason, the stress at the time of sealing can be concentrated on the tip 45 </ b> A, and the tip 45 </ b> A is in close contact with each nozzle opening 17, and reliable sealing is obtained. In the present embodiment, the radius of curvature at the tip 45A is about 3.5 mm.

  A configuration in which a rigid member is provided inside the elastic member 45 may be employed. Further, the shape of the elastic member 45 is not limited to the one shown above, and may be a shape that becomes narrower toward the tip.

  According to the ink jet printer 1 of the present embodiment, the nozzle openings 17 of the recording head 5 can be directly sealed by the elastic member 45 provided in the sealing portion 41 that is movable relative to the recording head 5. Since it is possible, the nozzle opening 17 can be reliably sealed. For this reason, it is not necessary to seal the entire nozzle surface of the recording head with the cap member as in the prior art, and it is not necessary to secure a seal area in the nozzle surface for contacting the cap member, which has been necessary in the past. The recording head 5 can be further downsized.

Next, the operation of the ink jet printer will be described with reference to FIGS. 2 and 5 to 7. FIG. 5 is an explanatory view showing a sealing operation by the sealing mechanism 11. FIG. 6 is a flowchart showing the operation of the sealing mechanism, and FIG. 7 is a graph showing the pressure change in the recording head 5 before and after sealing. In the following description, the sealing operation by the sealing mechanism 11 will be mainly described.
The ink jet printer 1 according to the present embodiment controls the position of the sealing portion 41 while monitoring the pressure in the recording head 5.

  First, in step S <b> 1, the control device 2 raises the sealing portion 41 by operating the sealing portion moving means 12 of the sealing mechanism 11 and presses each elastic member 45 against the nozzle surface 5 </ b> A of the recording head 5. To touch. The pressing force of the sealing portion 41 against the recording head 5 is constant and is appropriately set depending on the material, shape, etc. of the elastic member 45. For example, the amount of deformation of the elastic member 45 is measured as a measure of the pressing force. In this embodiment, as shown in FIG. 5B, the pressing force is such that the contact width W2 of the elastic member 45 with respect to the nozzle surface 5A of the recording head 5 is about 0.2 mm. For example, when a load of 0.08 N / mm is applied to the elastic member 45, the contact width W2 becomes about 0.2 mm.

  In step S <b> 2, the pressure in the recording head 5 is detected by the pressure detection device 10. In this step, detection is performed in a state where the supply pump 43 is driven and pressure is applied to the ink in the ink flow path 47. The pressure detection device 10 detects the ink pressure in the ink flow path 47 as the ink pressure of the recording head 5, and outputs the detected inspection signal to the control device 2.

  Next, in step S3, the sealing state of the nozzle row 16 (nozzle opening 17) is confirmed. If the detected pressure falls below a preset threshold value, it is determined that the nozzle opening 17 is not blocked at all, and the process proceeds to step 2 again.

  The control device 2 moves the sealing portion 41 in the horizontal direction in Step 2 and again detects the pressure in the recording head 5 at that position, and then checks the sealing state of the nozzle opening 17 in Step S3. In this embodiment, by repeatedly executing this operation, the position of the sealing portion 41 with respect to the recording head 5 is controlled while monitoring the pressure in the recording head 5.

FIG. 7 is a graph showing a sealed state of the nozzle openings.
As shown in FIG. 7, when the sealing portion 41 is moved in one direction with respect to the recording head 5, the pressure in the recording head 5 rises, reaches a peak exceeding the threshold, and then further seals. The pressure in the recording head 5 decreases due to the movement of the portion 41.

  The control device 2 determines that the nozzle opening 17 is securely sealed by the sealing portion 41 at the position where the highest pressure is detected, and moves the sealing portion 41 to this position to seal the nozzle opening 17. Stop.

  The control device 2 stores the sealing position, and performs the positioning of the sealing portion 41 with respect to the recording head 5 based on this data when the sealing operation is performed next time.

  As described above, in this embodiment, the position of the sealing portion 41 with respect to the recording head 5 is controlled while monitoring the pressure in the recording head 5. After detecting the sealing position, the nozzle opening 17 can be sealed by always bringing the sealing portion 41 into contact with the recording head 5 at the same position. As a result, the positioning of the sealing portion 41 with respect to the recording head 5 can be performed only once.

  In addition, it is desirable to check the sealing state of the nozzle opening 17 even after the nozzle opening 17 is sealed by the sealing portion 41 at the sealing position obtained by the operation as described above. In this case, after pressurizing the ink by the supply pump 43, the supply pump 43 is stopped, and by monitoring the subsequent pressure change in the recording head 5, it is possible to confirm whether the nozzle opening 17 is reliably sealed. .

  For example, as shown in FIG. 8, if the ink pressure in the recording head 5 is held at a pressure equal to or higher than a threshold value for a certain period of time, it can be determined that the nozzle opening 17 is reliably sealed. On the other hand, if the ink pressure decreases after the supply pump 43 is stopped, it is determined that the sealing is incomplete, and the sealing portion 41 is aligned with the recording head 5 again. Thus, by controlling the position of the sealing portion 41 based on the pressure detected by the pressure detection device 10, the control error can be alleviated and the sealing of the nozzle opening 17 by the elastic member 45 is ensured. be able to.

  Therefore, since the ink from the nozzle openings 17 can be prevented from being dried by the sealing mechanism 11 of the present embodiment, it is possible to maintain good ejection of the recording head 5 and obtain a highly reliable ink jet printer 1. It is done.

  When the position of the sealing portion 41 is adjusted, the position of the elastic member 45 relative to the nozzle opening 17 is moved by moving the sealing portion 41 in contact with the recording head 5 within a horizontal plane (XZ plane). Alternatively, the contact portion may be retried after adjusting the position of the sealing portion 41 after the sealing portion 41 is lowered and once separated from the recording head 5.

Next, another operation in the above-described sealing mechanism 11 will be described.
The sealing mechanism 11 can also perform a cleaning process (wiping process) for removing ink adhering to the nozzle surface 5A of the recording head 5 by causing the elastic member 45 of the sealing portion 41 to function as a wiper. FIG. 9 is an explanatory view showing a cleaning operation by the sealing mechanism.

  When executing the wiping process, first, as shown in FIG. 9A, the sealing portion 41 is raised and disposed on the side of the recording head 5 (outside in the short direction). At this time, the tip 45 </ b> A of the elastic member 45 erected on the edge of the base 44 is raised to a position where it contacts the side 5 b of the recording head 5.

  Then, as shown in FIG. 9B, each sealing member 41 is elastically deformed by moving the sealing part 41 along the arrangement direction of the nozzle rows 16 of the recording head 5 by the sealing part moving means 12. However, the nozzle surface 5A is sequentially contacted and slides on the nozzle surface 5A. By sliding the elastic member 45 on the nozzle surface 5A, it is possible to remove thickened ink or solidified ink in the nozzle opening 17 or in the vicinity thereof.

  Thus, the cleaning process by the sealing mechanism 11 is possible by causing the elastic member 45 of the sealing portion 41 to function as a wiper.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, the base portions (end portions opposite to the tip 45A) of the plurality of elastic members 45 may be integrated with each other. Further, the elastic member 45 may have a shape corresponding to the plurality of nozzle rows 16 provided in the recording head 5. For example, the elastic member may be formed to have a width corresponding to the nozzle row 16 for two rows, and the two nozzle rows may be collectively sealed with one elastic member. This facilitates the alignment of the elastic member with respect to each nozzle row 16 of the recording head 5.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printer (fluid ejecting apparatus), 5A ... Nozzle surface, 5 ... Recording head (fluid ejecting head), 16 (16Y, 16M, 16C, 16Bk) ... Nozzle row, 17 ... Nozzle opening, 10 ... Pressure detection apparatus ( Detection device), 45 ... elastic member, 45A ... tip

Claims (6)

A fluid ejecting head having a nozzle surface on which a nozzle row including a plurality of nozzle openings is formed;
An elastic member extending along the nozzle row and capable of sealing the plurality of nozzle openings belonging to the nozzle row and movable relative to the fluid ejecting head;
A fluid ejection device comprising: a detection device that detects a sealing state of the nozzle opening by the elastic member. The fluid ejecting apparatus according to claim 1, wherein the detection device detects a pressure of ink in the fluid ejecting head. The fluid ejecting apparatus according to claim 1, wherein a tip of the elastic member has a curved shape protruding outward. The fluid ejecting apparatus according to claim 1, wherein the elastic member is slidable on the nozzle surface. A plurality of the nozzle rows;
5. The fluid ejecting apparatus according to claim 1, further comprising a plurality of the elastic members arranged corresponding to a pitch of the plurality of nozzle rows. The fluid ejecting apparatus according to claim 1, wherein the elastic member faces a plurality of the nozzle rows.

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