JP7775735B2 - Droplet discharge device - Google Patents

Description

The present invention relates to a droplet ejection device.

The inkjet method is known for forming images by ejecting droplets. When droplets are ejected using the inkjet method, tiny droplets known as "mist" are scattered. If this mist adheres to the recording medium, image quality will deteriorate. Therefore, a technology is known in which the droplet ejection device collects the mist to improve image quality.

Specifically, the droplet ejection device is configured to include a carriage, a fan, an encoder, and a filter. The encoder is located downstream of the fan and upstream of the head in the direction of the airflow. The fan is also located downstream of the filter in the direction of the airflow. Technology using this type of configuration is known to more efficiently prevent degradation of image quality due to ink mist (see, for example, Patent Document 1).

With conventional technology, the size of the droplet ejection device increases due to the arrangement and structure of various devices.

The present invention was made in consideration of the above, and aims to reduce the size of droplet ejection devices.

In order to solve the above-mentioned problems and achieve the object, a droplet ejection device for ejecting droplets is provided,
a discharge unit that discharges the droplets;
a cap portion having a cap for sucking up waste liquid discharged by the discharge portion;
The nozzle includes a rail portion that determines the direction in which the cap portion moves and that captures and recovers material that is generated when the droplets are discharged.

This invention allows for the miniaturization of droplet ejection devices.

FIG. 1 is a diagram illustrating an example of a liquid ejection device. FIG. 10 is a diagram showing an example of a structure in which a head array, a sustaining unit, a rail, and a drum are arranged. FIG. 10 is a diagram showing an example of performing blank ejection. FIG. 2 is a diagram illustrating an example of the configuration of a head array. FIG. 2 is a diagram illustrating a configuration example of a maintenance unit. FIG. 10 is a diagram illustrating an example of the configuration of a maintenance rail. 10A and 10B are diagrams illustrating examples of movement directions of a head array and a sustaining unit. 10A and 10B are diagrams illustrating an example of the position of an opening when idle ejection is being performed. FIG. 10 is a diagram showing a first example of a case where blank ejection is performed. FIG. 10 is a diagram showing a second example of a case where blank ejection is performed.

Specific examples will be described below with reference to the accompanying drawings. Note that embodiments are not limited to the specific examples described below.

[Example of droplet ejection device]
Fig. 1 is a diagram showing an example of a droplet ejection device. For example, the droplet ejection device is an inkjet printer 1000 shown in Fig. 1. The following description will be given using the inkjet printer 1000 shown in Fig. 1 as an example of a droplet ejection device. Therefore, the inkjet printer 1000 performs a process of forming an image using ink, which is an example of droplets.

The inkjet printer 1000 is an image forming device that employs an on-demand line scanning method. The inkjet printer 1000 also includes an image forming unit 210, a paper feed unit 220, a registration adjustment unit 230, a drying unit 240, a recording medium inversion unit 250, and a paper discharge unit 290.

First, in the paper feed unit 220, paper W1, an example of a recording medium to be loaded in the paper feed stack 221, is picked up one by one by the air separation unit 222. Then, paper W1 is transported in the direction of the image forming unit 210 (to the left in the figure). Next, when paper W1 transported from the paper feed unit 220 reaches the registration adjustment unit 230, the inclination of paper W1 relative to the transport direction is corrected by a pair of registration rollers 231 provided inside the registration adjustment unit 230.

Once correction (such as registration adjustment) is made by the registration roller pair 231, the paper W1 is sent to the image forming unit 210. Then, the paper W1 is sent to the surface of the cylindrical drum 211 by the transport roller pair 214.

The drum 211 is provided with multiple recording medium grippers 212. The recording medium grippers 212 grip the leading edge of the paper W1. As the drum 211 rotates, the paper W1 is transported to a position facing multiple head arrays 100 (specifically, various head arrays 100K to 100P. Hereinafter, any head array 100 will be simply referred to as a "head array 100").

In the image forming unit 210, a head array 100 is arranged along the surface of a cylindrical drum 211 in the direction of rotation. The head array 100 ejects ink using an inkjet method. The head array 100 is arranged in a state where it is filled with a predetermined ink color.

The head arrays 100 are positioned at predetermined radial positions in accordance with the curvature of the outer peripheral surface of the drum 211. Specifically, the position of the head arrays 100 is adjusted so that the ink ejection direction is at a perpendicular angle to the surface of the drum 211. Therefore, each head array 100 is at a different angle in the radial direction from the rotation axis of the drum 211. In other words, the head arrays 100 that make up the ejection module are positioned at an angle facing the center of rotation of the drum 211. The opposing angle of each head array 100 to the drum 211 is then adjusted so that ink is ejected toward the outer peripheral surface of the paper W1 held on the surface of the drum 211.

In addition, an empty discharge receiver 213 is provided on the outer peripheral surface of the drum 211. The empty discharge receiver 213 receives empty discharged ink when the head array 100 is not discharging ink onto the paper W1.

Once the image is formed on paper W1, paper W1 is transported to the drying section 240.

The drying section 240 is provided with a drying unit 241. When the paper W1 passes below the drying unit 241, the moisture in the paper W1 evaporates.

The drying unit 240 is also provided with a recording medium inverting unit 250 that includes a recording medium inverting mechanism 251. When performing double-sided printing, the recording medium inverting unit 250 inverts the sheet W1. Next, the recording medium inverting unit 250 transports the sheet W1 again to the image forming unit 210. Before the sheet W1 reaches the drum 211, the skew of the sheet W1 is corrected by a registration roller 253 provided inside the image forming unit 210.

After drying, the paper W1 is transported to the paper discharge section 290 and stacked with the edges of the paper W1 aligned.

The droplet ejection operation in the image forming unit 210 is controlled by an image forming control unit 215 provided in the image forming unit 210. The image forming control unit 215 may also control the overall operation of the inkjet printer 1000. The paper feed unit 220, registration adjustment unit 230, and drying unit 240 may also each have their own control unit. Each control unit may then work in conjunction with the image forming control unit 215 to control the overall operation of the inkjet printer 1000.

Note that the inkjet printer 1000 is not limited to the configuration described above. Specifically, the inkjet printer 1000 may include internal or external devices other than those described above.

[Structure example]
2 is a diagram showing an example of a structure in which a head array, a sustaining unit, a rail, and a drum are arranged. Below, an example will be described in which the ejection unit is an example of a head array 100, the cap unit is an example of a sustaining unit 101, and the rail unit is an example of a sustaining rail 102. In the following description, the sustaining unit 101 moves in a direction along the sustaining rail 102 (the depth direction, or Y-axis direction, in the drawing).

The maintenance unit 101 accepts the head array 100 ejecting ink for maintenance (hereinafter referred to as "blank ejection") as follows:

Figure 3 shows an example of performing blank ejection. To perform maintenance (i.e., when image formation is not being performed), the suction cap 110 performs suction.

A pump 111 is connected to the suction cap 110. When the pump 111 applies suction, ink is forcibly discharged from the head array 100. In the figure, the ink is discharged downward, and the suction cap 110 receives the ink.

When blank ejection is performed in this manner, a substance such as ink mist (hereinafter referred to as "mist 112") is generated. This mist 112 may not be able to be completely collected by suction using the suction cap 110.

Therefore, a space is provided within the maintenance rail 102, allowing the maintenance rail 102 to collect the mist 112. In particular, when there is negative pressure inside the maintenance rail 102, the mist 112 flows in more easily, allowing the maintenance rail 102 to collect the mist 112.

With the above configuration, the inkjet printer 1000 can collect the mist 112 without having to be configured with an additional dedicated device for collecting the mist 112. Therefore, compared to configurations that require a dedicated device, the inkjet printer 1000 can be made smaller.

Note that the inkjet printer 1000 may be equipped with a number of head arrays 100, maintenance units 101, and maintenance rails 102 other than those described above, or may be equipped with types other than those described above.

[Head array configuration example]
Fig. 4 is a diagram showing an example of the configuration of a head array 100. The head array 100 is made up of a plurality of heads 41. Fig. 4 shows the head array 100 as seen from the ejection port side.

The heads 41 are arranged in a staggered pattern in a direction perpendicular to the transport direction in which the paper W1 is transported (in the figure, this is a direction perpendicular to the longitudinal direction of the head array 100). Note that the number and arrangement of the heads 41 may be other than those shown in the figure. For example, there may be only one head 41.

[Configuration example of maintenance unit]
5 is a diagram showing an example of the configuration of the maintenance unit 101. In addition to the suction cap 110, the maintenance unit 101 may also include a plurality of moisture retention caps 42, a wiping member 43, and a rail holding member 44.

The moisture retention cap 42 seals the nozzle surface of the head 41 when in standby mode, etc.

The wiping member 43 wipes and cleans the nozzle surface of the head 41.

The rail holding member 44 comes into contact with the support rail 102. The support unit 101 is then supported by the support rail 102 and other components.

Note that the maintenance unit 101 may have a configuration other than that shown in the figure. For example, the maintenance unit 101 may also include cleaning members, etc.

[Example of maintenance rail configuration]
6 is a diagram showing an example of the configuration of the support rail 102. For example, an opening 61 is formed in the support rail 102 at the position shown in the figure.

Mist 112 and other particles are drawn into the maintenance rail 102 through the opening 61. There is also space inside the maintenance rail 102. In the figure, the airflow containing mist 112 is drawn in through the opening 61 and flows inside the maintenance rail 102 in the direction indicated by the arrow.

A duct 62 is connected to the maintenance rail 102. The duct 62 is then connected to a pressure chamber 63. The pressure chamber 63 is then connected to a fan 64. It is desirable to install a filter 65, an example of a filter unit, upstream of the fan 64 (in the figure, the opening 61 is located at the most upstream position, to the left of the fan 64). Installing the filter 65 in this position reduces the workload for the user when replacing it.

The fan 64 operates to suck in the airflow. When the fan 64 sucks in, the air pressure in the pressure chamber 63 etc. drops, making it easier for the mist 112 etc. to be sucked into the inside of the maintenance rail 102.

The filter 65 is a component that collects the mist 112 and allows air to pass through. Therefore, the filter 65 filters the airflow containing the mist 112.

It is desirable to install the filter 65 in a position upstream of the fan 64 in the airflow path formed by the maintenance rail 102. When the filter 65 is placed in this position, it is in front of the fan 64, etc. This makes it easy for the user to replace the filter 65.

In this way, the maintenance rail 102 forms an airflow path with the opening 61 as its inlet. Therefore, the mist 112 flows through the opening 61, the inside of the maintenance rail 102, and the filter 65 in that order, and is collected by the filter 65.

The inkjet printer 1000 moves the head array 100, the maintenance unit 101, and the maintenance rail 102 as follows:

Figure 7 shows an example of the movement direction of the head array and the sustaining unit. The head array 100 moves in a direction up and down relative to the sustaining rail 102 (hereinafter referred to as the "vertical direction 71"). Meanwhile, the sustaining unit 101 moves in a direction parallel to the sustaining rail 102 (hereinafter referred to as the "horizontal direction 72").

The inkjet printer 1000 is preferably configured to move the maintenance unit 101 using a drive unit. For example, the drive unit may be an actuator, a mechanical component, or the like.

By moving the maintenance unit 101 in the horizontal direction 72, the inkjet printer 1000 can position the suction cap 110 in a position opposite the head 41 of the head array 100.

Next, after positioning the head 41 and suction cap 110 so that they face each other, the inkjet printer 1000 performs a blank discharge. When performing a blank discharge, the suction cap 110 is preferably positioned as follows:

Figure 8 shows an example of the position of the opening when blank ejection is being performed. Note that for the sake of explanation, Figure 8 does not show the head array 100.

Figure 8(A) is a view from the same perspective as Figure 7 (hereinafter referred to as a front view). On the other hand, Figure 8(B) is a side view.

The maintenance unit 101 may include a side member 80. The side member 80 is installed between the suction cap 110 and the maintenance rail 102. When such a side member 80 is included, it is desirable that the side member 80 have an opening at the position of the suction cap 110 in the horizontal direction 72. When including such a side member 80, for example, the inkjet printer 1000 performs blank ejection as follows.

Figure 9 shows a first example of when blank ejection is performed.

Figure 10 shows a second example of blank ejection.

Comparing Figures 9 and 10, the maintenance unit 101 has moved and is now in a different position in the horizontal direction 72. In this way, the side member 80 opens, forming a cavity connecting the suction cap 110 and the opening 61.

When idle ejection is performed on a side member 80 with such a cavity, the inkjet printer 1000 can suck in the mist 112 generated by the idle ejection through the cavity, thereby increasing suction power. As a result, the inkjet printer 1000 can collect more mist 112.

As described above, the droplet ejection device includes a cap unit with a cap that sucks up waste liquid discharged by the ejection unit during idle ejection. The cap unit moves in a direction determined by the rail unit. The rail unit then forms a path within it for collecting generated material. Specifically, the rail unit forms a path in a direction parallel to the direction in which the cap unit moves.

It is desirable to have the suction unit located at the most downstream position on the path. Therefore, any material generated during idle discharge is taken in through an opening formed in the rail section and flows in the suction direction toward the suction unit. If a filter unit is installed upstream of the suction unit, the filter unit will collect the material. In this way, when the device for collecting material and the rail section are integrated into a structure, the device is built-in, allowing for a more compact droplet discharge device compared to when a dedicated recovery device is installed.

Furthermore, with this type of structure, particles generated by multiple head arrays can be collected by a common device. Therefore, by standardizing the device for collecting particles, the droplet ejection device can be made more compact.

[Other embodiments]
The mist 112 may be collected during a period other than idle ejection. For example, the mist 112 may be collected while image formation is being performed.

The droplets may be of a type other than ink. That is, the droplet ejection device may use droplets other than ink to perform processes other than image formation. For example, the droplets may be pre-application liquid or post-treatment liquid, etc.

The generated material may include substances other than mist.

The present invention is not limited to the above-described exemplary embodiments. Therefore, the present invention allows for the addition or modification of components without departing from the technical gist of the invention. Therefore, all technical matters included in the technical concept described in the claims are within the scope of the present invention. The above-described exemplary embodiments are preferred examples. Furthermore, those skilled in the art will be able to realize various modifications from the disclosed content, and such modifications are within the technical scope described in the claims.

41: Head 61: Opening 62: Duct 63: Pressure chamber 64: Fan 65: Filter 71: Vertical direction 72: Horizontal direction 80: Side member 100: Head array 101: Maintenance unit 102: Maintenance rail 110: Suction cap 111: Pump 112: Mist 1000: Inkjet printer W1: Paper

Japanese Patent Application Laid-Open No. 2021-123103

Claims (4)

A droplet ejection device that ejects droplets,
a discharge unit that discharges the droplets;
a cap portion having a cap for sucking up waste liquid discharged by the discharge portion;
The droplet ejection device includes a rail portion that determines the direction in which the cap portion moves and that captures and recovers material that is generated when the droplets are ejected. a filter unit that collects the generated matter and allows air to pass through;
Further provided is a suction unit that sucks the generated material,
The filter unit includes:
The droplet discharge device according to claim 1 , wherein the droplet discharge device is disposed upstream of the suction section in a path through which the generated material passes after being collected. a side member is provided between the cap portion and the rail portion;
3. The droplet ejection device according to claim 1, wherein the side member has an opening and a cavity connecting the opening of the cap portion and the opening of the rail portion. a drive unit that moves the cap unit along the rail unit;
a suction unit that sucks the generated material and air to lower the air pressure;
a filter unit that collects the generated matter and allows the air to pass through,
The discharge section is
The droplets are ejected to form an image;
The cap portion is
Accepting blank discharge when the discharge unit does not form the image,
The drive unit is
When performing the blank discharge, the cap portion is moved to a position facing the discharge portion,
The rail portion is
A droplet ejection device according to any one of claims 1 to 3, which forms an opening for taking in the generated material and the air, and a path for passing the generated material and the air, and which takes in and recovers the generated material generated during the empty ejection into the path.