JP7095318B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

The mist recovery mechanism described in Patent Document 1 has a suction port for sucking air containing mist and an outlet for blowing air to guide the air containing mist to the suction port.

Japanese Patent Application Laid-Open No. 2015-083372

The subject of the present invention is that the blowing direction of the air blown out from the outlet is inclined to the downstream side in the transport direction of the recording medium when viewed from the width direction of the recording medium, and the inclination angle is larger than 60 [degrees], or This is to suppress the adhesion of mist to the recording medium as compared with the case where it is smaller than 20 [degrees].

The image forming apparatus according to the first aspect of the present invention has a nozzle surface on which a plurality of nozzles for ejecting droplets toward the recording medium are formed, and the plurality of images are arranged at intervals in the transport direction of the recording medium. Droplet ejection head and an outlet that is arranged between the droplet ejection heads adjacent to each other in the transport direction of the recording medium and blows air toward the recording medium, and an outlet on the upstream side of the outlet in the transport direction of the recording medium. It has a suction port for sucking the air blown out from the outlet together with the mist of the droplets, and the blowing direction of the air blown out from the outlet is the width direction of the recording medium. Between the mist recovery device that is tilted downstream in the transport direction and the tilt angle is 20 [degrees] or more and 60 [degrees] or less, and the droplet ejection head and the mist recovery device that are adjacent to each other in the transport direction of the recording medium. A surface facing the recording medium to be conveyed is formed, and a suppressing member for suppressing the entry of the mist of the droplet between the droplet ejection head and the mist collecting device is provided. It is characterized by being prepared.

The image forming apparatus according to the second aspect of the present invention has a nozzle surface on which a plurality of nozzles for ejecting droplets toward the recording medium facing the conveyed recording medium are formed, and the transfer direction of the recording medium. A plurality of droplet ejection heads arranged at intervals, an outlet arranged between the droplet ejection heads adjacent to each other in the transport direction of the recording medium, and an outlet for blowing air toward the recording medium, and a recording medium. On the upstream side of the outlet in the transport direction, the outlet has a suction port for sucking the air blown from the outlet together with the mist of the droplet, and an outlet through which the air blown from the outlet flows. The path is inclined to the downstream side of the recording medium in the transport direction when viewed from the width direction of the recording medium, and the mist recovery device having an inclination angle of 20 [degrees] or more and 60 [degrees] or less and the recording medium in the transport direction. A facing surface is formed between the adjacent droplet ejection head and the mist collecting device and facing the recording medium to be conveyed, and the droplet mist is transferred to the droplet ejection head and the mist collecting device. It is characterized by comprising a restraining member that suppresses entry between the two.

The image forming apparatus according to the third aspect of the present invention is the image forming apparatus according to the first or second aspect , in which the mist collecting device faces the recording medium and the outlet and the suction port are formed. Assuming that the distance from the other facing surface to the recording medium is L1 and the distance from the outlet to the suction port in the transport direction of the recording medium is L2, the following equation (1) is used. Is characterized by the fact that.
L2 ≤ L1 × 10 ... (1)

The image forming apparatus according to the fourth aspect of the present invention is the image forming apparatus according to the third aspect . It has a suction path formed including an upstream wall surface facing the surface, and in the other facing surface, a portion between the suction port and the air outlet is set as the first facing surface, and the first facing surface and the upstream wall surface are used. The ridgeline formed by and is characterized in that a chamfered portion is formed.

The image forming apparatus according to the fifth aspect of the present invention is the image forming apparatus according to any one of the first to fourth aspects , wherein the mist collecting device faces the recording medium, and the outlet and the above. It has another facing surface on which a suction port is formed and a suction path through which air sucked from the suction port flows, and the suction path is recorded by the other facing surface when viewed from the width direction of the recording medium. It is characterized in that it extends in the direction facing the medium or is inclined to the downstream side in the transport direction of the recording medium.

The image forming apparatus according to the sixth aspect of the present invention is the image forming apparatus according to the fifth aspect , in which the mist recovery device has an outlet through which air blown from the outlet flows, and the suction path has a suction path. It is characterized in that it extends along the outlet when viewed from the width direction of the recording medium.

The image forming apparatus according to the seventh aspect of the present invention is the image forming apparatus according to any one of the first to sixth aspects , wherein the mist collecting device faces the recording medium, and the outlet and the above. It has another facing surface on which a suction port is formed, and the portion between the suction port and the outlet is the first facing surface on the other facing surface, and the suction port is in the transport direction of the recording medium. When the portion on the upstream side is the second facing surface, the distance from the second facing surface to the recording medium is longer than the distance from the first facing surface to the recording medium. It is characterized by.

The image forming apparatus according to the eighth aspect of the present invention is the image forming apparatus according to the seventh aspect . It has a suction path formed including a facing downstream wall surface, and is characterized in that a chamfered portion is formed on the ridge line between the second facing surface and the downstream wall surface.

The image forming apparatus according to the ninth aspect of the present invention is the image forming apparatus according to any one of the first to eighth aspects. It has another facing surface on which a suction port is formed, and the air blown out from the air outlet flows between the other facing surface and the recording medium and is sucked in from the suction port to capture the mist contained in the air. Then, it is characterized in that it is blown out from the outlet again.

According to the image forming apparatus of the first aspect of the present invention, the blowing direction of the air blown from the outlet is inclined to the downstream side in the transport direction of the recording medium when viewed from the width direction of the recording medium, and the tilt angle is 60. It is possible to suppress the adhesion of mist to the conveyed recording medium as compared with the case where it is larger than [degree] or smaller than 20 [degree].

According to the image forming apparatus of the second aspect of the present invention, the outlet is inclined to the downstream side in the transport direction of the recording medium when viewed from the width direction of the recording medium, and the inclination angle is larger than 60 [degrees], or It is possible to suppress the adhesion of mist to the conveyed recording medium as compared with the case where it is smaller than 20 [degrees].

According to the image forming apparatus of the third aspect of the present invention, the recorded image to be conveyed is compared with the case where the distance L2 from the outlet to the suction port is larger than 10 times the distance L1 from the other facing surface to the recording medium. It is possible to suppress the adhesion of mist to the medium.

According to the image forming apparatus of the fourth aspect of the present invention, the distance from the air outlet to the suction port is shortened as compared with the case where a corner portion (pin angle) is formed between the first facing surface and the upstream wall surface. can do.

According to the image forming apparatus of the fifth aspect of the present invention, the suction path is blown out from the outlet as compared with the case where the suction path is inclined to the upstream side in the transport direction of the recording medium when viewed from the width direction of the recording medium. The amount of air that flows upstream in the transport direction of the recording medium and is sucked in from the suction port can be increased.

According to the image forming apparatus of the sixth aspect of the present invention, the minimum thickness between the suction path and the outlet path is compared with the case where the suction path extends in the direction facing the recording medium with the other facing surfaces facing each other. It is possible to shorten the distance from the air outlet to the suction port while maintaining this.

According to the image forming apparatus of the seventh aspect of the present invention, mist adheres to the recording medium as compared with the case where the distance from the second facing surface to the recording medium is the same as the distance from the first facing surface to the recording medium. Can be suppressed.

According to the image forming apparatus of the eighth aspect of the present invention, the adhesion of mist to the recording medium is suppressed as compared with the case where the corner portion (pin angle) is formed between the second facing surface and the downstream wall surface. can do.

According to the image forming apparatus of the ninth aspect of the present invention, the number of parts can be reduced as compared with the case of using the discharge mechanism for discharging the air sucked from the suction port to the outside of the device.

It is an enlarged sectional view which showed the blowing path and the suction path of the mist recovery device of the image forming apparatus which concerns on 1st Embodiment of this invention. It is an enlarged sectional view which showed the blowing path and the suction path of the mist recovery device of the image forming apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the mist recovery apparatus of the image forming apparatus which concerns on 1st Embodiment of this invention. (A) (B) (C) It is a figure which showed the evaluation result at the time of having evaluated the mist recovery apparatus of the image forming apparatus which concerns on 1st Embodiment of this invention in a graph. It is a figure which showed the evaluation result at the time of having evaluated the mist recovery apparatus of the image forming apparatus which concerns on 1st Embodiment of this invention in a graph. It is a figure which showed the evaluation result at the time of having evaluated the mist recovery apparatus of the image forming apparatus which concerns on 1st Embodiment of this invention in a table. It is a perspective view which showed the support member of the image forming apparatus which concerns on 1st Embodiment of this invention. It is a front view which showed the droplet ejection head of the image forming apparatus which concerns on 1st Embodiment of this invention, and the mist recovery apparatus. It is a schematic block diagram which showed the image forming apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the modified form of the image forming apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the comparative form of the image forming apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the comparative form of the image forming apparatus which concerns on 1st Embodiment of this invention. It is an enlarged sectional view which showed the blowing path and the suction path of the mist recovery device of the image forming apparatus which concerns on 2nd Embodiment of this invention. It is an enlarged sectional view which showed the blowing path and the suction path of the mist recovery device of the image forming apparatus which concerns on 3rd Embodiment of this invention. It is an enlarged sectional view which showed the blowing path and the suction path of the mist recovery device of the image forming apparatus which concerns on 4th Embodiment of this invention. It is sectional drawing which showed the modification of embodiment of this invention.

<First Embodiment>
An example of the image forming apparatus according to the first embodiment (reference embodiment) of the present invention will be described with reference to FIGS. 1 to 12. The arrow H shown in the figure indicates the device vertical direction (vertical direction), the arrow W indicates the device width direction (horizontal direction), and the arrow D indicates the device depth direction (horizontal direction).

(Overall configuration of image forming apparatus 10)
As shown in FIG. 9, the image forming apparatus 10 ejects from a conveying mechanism 20 that conveys continuous paper P as a recording medium, a droplet ejection head 30 that forms an image by an inkjet method, and a droplet ejection head 30. It is provided with a mist collecting device 40 for collecting the mist of the dropped droplets.

[Transport mechanism 20]
The transport mechanism 20 rotationally drives the unwinding roll 22 for unwinding the continuous paper P, the winding roll 24 for winding the continuous paper P, the plurality of transport rolls 26 for transporting the continuous paper P, and the winding roll 24. It includes a drive unit 28. As a result, the take-up roll 24 rotates in the direction of the arrow in the drawing to take up the continuous paper P, and the take-up roll 22 unwinds the continuous paper P.

Further, the plurality of transport rolls 26 are so-called driven rolls, and are wound around the continuous paper P between the unwinding roll 22 and the winding roll 24. As a result, the plurality of transport rolls 26 define the transport path 102 of the continuous paper P from the unwinding roll 22 to the take-up roll 24. The transport roll 26 forms an arc path 102A that transports the continuous paper P in an arc shape that is convex upward when viewed from the depth direction of the device.

[Droplet ejection head 30]
Four droplet ejection heads 30 are provided for each color, and are arranged above the continuous paper P so as to face the continuous paper P conveyed in the arc path 102A in the vertical direction. In the present embodiment, the droplet ejection head 30Y for ejecting Y (yellow) droplets, the droplet ejection head 30M for ejecting M (magenta) droplets, and the droplet ejection for C (cyan) droplets are ejected. The head 30C and the droplet ejection head 30K for ejecting K (black) droplets are provided. Then, the droplet ejection head 30K, the droplet ejection head 30C, the droplet ejection head 30M, and the droplet ejection head 30Y are arranged in this order from the upstream side to the downstream side in the transport direction of the continuous paper P at intervals. I'm out. In the following description, if each color is not particularly distinguished, the alphabet of the code may be omitted.

The droplet ejection head 30 has a rectangular parallelepiped shape extending in the depth direction of the device, and as shown in FIG. 8, the droplet ejection head 30 has a nozzle surface 32 on which a plurality of nozzles (not shown) are formed. Is formed, and the nozzle surface 32 faces the continuous paper P to be conveyed.

[Mist recovery device 40]
As shown in FIG. 9, four mist collecting devices 40 are provided, and face the continuous paper P in the vertical direction on the downstream side in the transport direction of the continuous paper P with respect to the droplet ejection head 30 of each color. Arranged to do. The details of the mist recovery device 40 will be described later.

(Main part composition)
Next, the mist recovery device 40, and the support member 80 that supports the mist recovery device 40 and the droplet ejection head 30 will be described. In the following description, the mist collecting device 40 facing the continuous paper P in the portion where the transport path is along the device width direction when viewed from the device depth direction will be described as an example.

[Mist recovery device 40]
The mist collecting device 40 has a rectangular parallelepiped shape extending in the depth direction of the device, and as shown in FIGS. 8 and 9, on the downstream side in the transport direction of the continuous paper P with respect to the droplet ejection head 30 of each color. , Are arranged so as to face the continuous paper P, respectively. That is, the three mist collecting devices 40 on the upstream side in the transport direction of the continuous paper P are arranged between the droplet ejection heads 30 adjacent to each other in the transport direction of the continuous paper P. As shown in FIG. 3, the mist recovery device 40 includes a housing 44, a fan 46 arranged inside the housing 44, and a filter 48.

-Case 44-
The housing 44 includes a box-shaped main body portion 50 having an opening at the bottom and a closing portion 52 that closes the opening of the main body portion 50. The closed portion 52 has a plate shape in which the plate surface (the facing surface 52A described later) faces the facing direction in which the mist collecting device 40 faces the continuous paper P (hereinafter, simply referred to as “device facing direction”). The thickness (plate thickness) of is made thicker than the thickness of the wall plate 50A forming the main body portion 50.

Further, the closed portion 52 is formed with a facing surface 52A facing the continuous paper P to be conveyed. The facing surface 52A is an example of another facing surface. Further, on the facing surface 52A, the air outlet 56 that blows air toward the recording medium is located on the upstream side of the continuous paper P in the transport direction, and the air outlet 56 is blown upstream of the continuous paper P in the transport direction. A suction port 60 for sucking in the air blown out from the outlet 56 is formed.

Further, in the closed portion 52, an outlet 56 is formed at the lower end, and an outlet 58 through which the air blown out from the outlet 56 flows while penetrating the closed portion 52 is formed. In other words, the lower end of the outlet 58 is the outlet 56. Further, a suction port 60 is formed at the lower end of the closed portion 52, and a suction path 62 is formed so as to penetrate the closed portion 52 and allow air sucked from the suction port 60 to flow. In other words, the lower end of the suction path 62 is the suction port 60.

Next, the outlet 56 and the outlet 58 will be described.
As shown in FIGS. 2 and 3, the outlet path 58 is inclined to the downstream side in the transport direction of the continuous paper P when viewed from the device depth direction (width direction of the continuous paper P). Specifically, the lower end of the blowout path 58 is arranged on the downstream side in the transport direction of the continuous paper P as compared with the upper end of the blowout path 58.

When viewed from the device depth direction (width direction of the continuous paper P), the inclination angle of the outlet path 58 (θ1 in FIG. 2) is 20 [degrees] or more with respect to the device facing direction (vertical direction in FIG. 2). It is said to be 60 [degrees] or less.

Further, in the present embodiment, the blowout width (B1 in the figure) of the blowout path 58 is set to 1 [mm]. The outlet 58 is formed so as to extend in the depth direction of the device. The outlet 56 is formed at the lower end of the outlet 58.

Further, inside the housing 44, a support portion 54 that supports the fan 46 and the filter 48 from below is formed. The support portion 54 is L-shaped when viewed from the depth direction of the device, and has a vertical portion 54A extending in the vertical direction of the device and a horizontal portion 54B extending in the width direction of the device from the upper end of the vertical portion 54A. There is. Specifically, the lower end of the vertical portion 54A is attached to a portion between the upper end of the outlet path 58 and the upper end of the suction path 62 in the opposite surface 52B of the closed portion 52 formed on the opposite side of the facing surface 52A. ing. Further, the horizontal portion 54B extends from the upper end of the vertical portion 54A to one side (right side in the figure) in the device width direction. One end of the horizontal portion 54B in the device width direction is separated from the wall plate 50A of the housing 44.

In this configuration, the blowing direction of the air blown out from the outlet 56 is the same as the tilting direction of the blowing path 58, and is tilted to the downstream side in the transport direction of the continuous paper P when viewed from the depth direction of the device. Specifically, the air blowing direction is 20 [degrees] or more and 60 [degrees] or less with respect to the device facing direction. In other words, the air blown out from the outlet 56 is directed to the portion of the continuous paper P on the downstream side in the transport direction with respect to the portion facing the outlet 56.

Next, the suction port 60 and the suction path 62 will be described.
As shown in FIGS. 2 and 3, the suction path 62 is arranged on the upstream side of the ejection path 58 in the transport direction of the continuous paper P, and extends in the device facing direction when viewed from the device depth direction. .. Further, in the present embodiment, the suction width (B2 in the figure) of the suction path 62 is set to 3 [mm]. The suction path 62 is formed so as to extend in the depth direction of the device. The suction port 60 is formed at the lower end of the suction path 62.

Further, a sponge member 64, which is a porous body that absorbs liquid, is formed on the wall surface of the suction path 62. The member forming the wall surface of the suction path 62 may be a member that captures mist, and may be, for example, a non-woven fabric or the like.

Further, assuming that the distance from the facing surface 52A to the continuous paper P is L1 and the distance from the outlet 56 to the suction port 60 in the transport direction of the continuous paper P (left-right direction in FIG. 2) is L2, the following equation (1) is used. Is established. The distance from the facing surface 52A to the continuous paper P shown in each figure is widened in order to show the air flow between the facing surface 52A and the continuous paper P.
L2 ≤ L1 × 10 ... (1)

Here, the distance from the outlet 56 to the suction port 60 is the shortest distance from the edge portion of the outlet 56 to the edge portion of the suction port 60. Regarding the distance L2, considering the mist recovery performance described later, it is preferably 6 times or less of L1, and more preferably 3 times or less of L1.

Further, in order to stabilize the blowing direction of the air blown from the blowing port 56, it is necessary to lengthen the blowing path 58. Therefore, the minimum value of the distance L2 is preferably 2 [mm] or more, and more preferably 4 [mm] or more. In the present embodiment, the distance L1 is 1 [mm], and the distance L2 is 10 [mm].

-Fan 46, filter 48-
As shown in FIG. 3, the fan 46 and the filter 48 are arranged side by side in the device width direction inside the housing 44. Specifically, the fan 46 and the filter 48 are arranged in this order from one side (right side in the figure) to the other side (left side in the figure) in the device width direction, and are arranged in this order on the horizontal portion 54B of the support portion 54 from below. It is supported. The wall plate 50A on one side in the device width direction of the housing 44 and the fan 46 are separated from each other in the device width direction, and the wall plate 50A and the filter 48 on the other side in the device width direction of the housing 44 are devices. Separated in the width direction.

A plurality of fans 46 are axial flow fans and are provided side by side in the depth direction of the device so that air flows from the other side (left side in the figure) to one side (right side in the figure) in the width direction of the device. There is.

The filter 48 is a plate-shaped member for capturing mist flowing with air, and the plate surface faces the device width direction. The filter 48 is a member that captures the mist M and allows air to pass therethrough. The filter 48 extends in the depth direction of the device.

[Support member 80]
As shown in FIGS. 3 and 9, the support member 80 is arranged above the arc path 102A on which the continuous paper P is conveyed in an arc shape. The support member 80, the mist recovery device 40, and the discharge head 30 form a space between the arc path 102A. In the embodiment, the support member 80 has an arc shape along the arc path 102 when viewed from the width direction of the device, and the support member 80 is formed with a facing surface 80A facing the continuous paper P. The support member 80 is an example of a restraining member.

Further, as shown in FIG. 7, in the support member 80, rectangular through holes 80B extending in the depth direction of the device are spaced from the upstream side to the downstream side in the transport direction of the continuous paper P. Multiple pieces are formed with a gap. The lower end of the droplet ejection head 30 and the lower end of the mist collecting device 40 are inserted into the through hole 80B, respectively. Then, with the facing surface 80A of the support member 80, the nozzle surface 32 of the droplet ejection head 30, and the facing surface 52A of the mist collecting device 40 arranged on the same curved surface, the droplet ejection head 30 and the mist The recovery device 40 is attached to the support member 80 using an attachment member (not shown) (see FIG. 8). The support member 80 does not have a function of supporting the droplet ejection head 30, for example, and the mist M of the droplet ejected from the droplet ejection head 30 is the droplet ejection head 30 and the mist collecting device 40. It suffices to have a function of suppressing entry between and. In this case, another member that supports the droplet ejection head 30 is required. The support member 80 may not be integrated, but may be divided and function as a restraining member by a combination so as to face the 102A on the arc path.

(Action)
Next, the operation of the mist recovery device 40 will be mainly described.

When the image forming apparatus 10 is operated and the image forming apparatus 10 receives an image forming instruction, the continuous paper P is conveyed, and droplets (ink droplets) are conveyed toward the continuous paper P to which the droplet ejection head 30 of each color is conveyed. Is discharged. Mist (mist-like liquid) is also ejected from the droplet ejection head 30 together with the droplets. This mist M flows along the continuous paper P to be conveyed from the upstream side to the downstream side in the transport direction of the continuous paper P while floating in the air.

On the other hand, in the mist recovery device 40 shown in FIG. 3, when the fan 46 is operated, the fan 46 causes air to flow from the other side (left side in the figure) to one side (right side in the figure) in the width direction of the device. In other words, the fan 46 sucks the air on the other side in the device width direction with respect to the fan 46, and discharges the air to one side in the device width direction with respect to the fan 46. The air discharged from the fan 46 hits the wall plate 50A and flows downward (see arrow G1 in FIG. 3). Further, the air flowing downward hits the opposite surface 52B of the closed portion 52 and flows to the other side in the width direction of the device (see arrow G2 in FIG. 3). Further, the air flowing to the other side in the width direction of the device hits the vertical portion 54A of the support portion 54 and flows to the outlet path 58 (see the arrow G3 in FIG. 3).

Further, when the fan 46 sucks the air on the other side in the width direction of the device with respect to the fan 46, the air between the continuous paper P and the suction port 60 is sucked from the suction port 60, and the sucked air is sucked. , Flows through the suction path 62 and flows upward from the suction path 62 (arrow G4 in FIG. 3). Further, the air flowing upward flows to the fan 46 side through the filter 48 (see the arrow G5 in FIG. 3).

Here, as shown in FIG. 1, the air flowing to the outlet 58 is blown toward the continuous paper P conveyed from the outlet 56. Further, as described above, the air between the continuous paper P and the suction port 60 is sucked from the suction port 60 (arrow G4 in FIG. 1). Therefore, the air blown toward the continuous paper P conveyed from the outlet 56 is folded back toward the upstream side in the conveying direction of the continuous paper P and is sucked from the suction port 60 (arrow G6 in FIG. 1). As a result, an air flow flowing from the surface of the continuous paper P to the suction port 60 is generated between the suction port 60 and the continuous paper P (part J1 in the figure).

Therefore, the mist M that flows while floating in the air along the continuous paper P to be conveyed to the downstream side in the transport direction of the continuous paper P is blocked by this air flow and passes through the suction port 60 to the suction path 62. It flows in. Further, the mist M flowing into the suction path 62 is collected by being captured by the filter 48.

Next, the result of evaluating the mist recovery rate of the mist M flowing downstream of the continuous paper P in the transport direction along the continuous paper P by analysis will be described. The mist recovery rate is the ratio of the mist M that can be recovered to the generated mist M.

[Factor evaluation]
First, the factors that significantly change the mist recovery rate were evaluated using analysis. The scale is the same for the vertical axis of each figure of FIG. 4 described below.

FIG. 4A shows a graph in which the vertical axis represents the mist recovery rate and the horizontal axis represents the suction width B2 (see FIG. 2) of the suction path 62. From this graph, it can be seen that the change in the mist recovery rate depending on the size of the suction width B2 is small.

FIG. 4B shows a graph in which the vertical axis is the mist recovery rate and the horizontal axis is the inclination angle θ1 of the outlet path 58 (see FIG. 2). From this graph, it can be seen that the change in the mist recovery rate depending on the magnitude of the inclination angle θ1 is large.

FIG. 4C shows a graph in which the vertical axis represents the mist recovery rate and the horizontal axis represents the distance L2 (see FIG. 2) from the outlet 56 to the suction port 60. From this graph, it can be seen that the change in the mist recovery rate depending on the size of the distance L2 is large.

From the above factor evaluation results, it can be seen that the mist recovery rate is significantly changed by changing the inclination angle θ1 of the outlet path 58 or the distance L2 from the outlet 56 to the suction port 60.

-Tilt angle θ1-
Next, the inclination angle θ1 of the outlet path 58 was set in detail, and the relationship between the inclination angle θ1 and the mist recovery rate was evaluated using analysis.

FIG. 5 shows a graph in which the vertical axis is the mist recovery rate and the horizontal axis is the inclination angle θ1 of the outlet path 58 (see FIG. 2). From this graph, it can be seen that the change in the mist recovery rate depending on the magnitude of the inclination angle θ1 is large.

In the analysis, the transport speed of the continuous paper P is 100 [m / min], the blow speed of the air blown from the outlet is 3 [m / s], and the suction speed of the air sucked from the suction port is set. It was set to 1 [m / s]. Further, the distance L1 from the facing surface 52A to the continuous paper P was set to 1 [mm], and the distance L2 from the outlet 56 to the suction port 60 was set to 20 [mm].

As can be seen from the graph shown in FIG. 5, the inclination angle is 20 [degrees] or more and 60 [degrees] or less, and the mist recovery rate is 82 [%] or more. From experience, when the mist recovery rate calculated by analysis is 82 [%], the deterioration of the quality of the output image due to the mist M adhering to the continuous paper P on which the halftone image is formed is acceptable in terms of commerciality. Although it is a level, it is more preferable that the inclination angle is 30 [degrees] or more and 45 [degrees] or less.

-Discussion-
Next, the above-mentioned results will be considered. By setting the tilt angle to 20 [degrees] or more and 60 [degrees] or less, as shown in FIG. 1, the air blown out toward the continuous paper P conveyed from the outlet 56 is the continuous paper P. Fold back to the upstream side in the transport direction near the surface. Specifically, the air blown out from the outlet 56 once goes to the downstream side in the transport direction of the continuous paper P, and is folded back to the upstream side in the transport direction near the surface of the continuous paper P. Then, the folded air flows to the lower part of the suction port 60, and heads upward here (arrow G6 in FIG. 1).

Therefore, below the suction port 60, an air flow flowing from the vicinity of the surface of the continuous paper P to the suction port 60 is generated (site J1). It is considered that the mist M flowing from the upstream side in the transport direction of the continuous paper P hits this air flow, is blocked, and is sucked into the suction path 62 from the suction port 60.

On the other hand, in the first comparative mode in which the tilt angle is larger than 60 [degrees], since the tilt angle is large, as shown in FIG. 11, the paper is blown out toward the continuous paper P conveyed from the outlet. In the air, the proportion of the continuous paper P flowing downstream in the transport direction increases (arrow G10 in FIG. 11). Therefore, the amount of air (arrow G11 in FIG. 11) that is blown out from the outlet toward the continuous paper P and turned back toward the upstream side in the transport direction is reduced. Therefore, when the air flow (site J2) flowing from the vicinity of the surface of the continuous paper P to the suction port is weakened, the damming effect is weakened, and the amount of mist M sucked from the suction port 60 into the suction path 62 is reduced. think.

Further, in the second comparative mode in which the tilt angle is smaller than 20 [degrees], the tilt angle is small, so that the air blown out toward the continuous paper P conveyed from the outlet is as shown in FIG. , Fold back to the upstream side in the transport direction before reaching the vicinity of the surface of the continuous paper P (arrow G20 in FIG. 11). Then, the folded air flows to the lower part of the suction port 60, and heads upward here. Therefore, below the suction port 60, an air flow flowing to the suction port 60 is generated from a position away from the surface of the continuous paper P (site J3). As a result, it is considered that the amount of mist M that hits the air flow and is blocked is reduced, and the amount of mist M that is sucked into the suction path 62 from the suction port 60 is reduced.

-Distance from the air outlet to the suction port L2-
Next, the distance L2 from the outlet 56 to the suction port 60 was set in detail, and the relationship between the distance L2 and the mist recovery rate was evaluated using analysis.

In FIG. 6, when the inclination angle θ1 of the outlet path 58 is 20 [degrees] and 60 [degrees], and the distance L2 from the outlet 56 to the suction port 60 is 4 [mm] to 20 [mm]. The mist recovery rate of is shown in the table.

The case where the mist recovery rate is 82 [%] or more is defined as "C", the case where the mist recovery rate is 84 [%] or more is "B", and the case where the mist recovery rate is 86 [%] or more is "A". As can be seen from the table shown in FIG. 6, when the distance L2 is 4 [mm] or more and 6 [mm] or less, the evaluation is “A”, and when the distance L2 is 8 [mm] or more and 10 [mm] or less. In addition, the evaluation was "B", and when the distance L2 was 12 [mm] or more and 20 [mm] or less, the evaluation was "C".

From experience, when the mist recovery rate calculated by the analysis is 84 [%], the mist M adhering to the continuous paper P can be found, but it is not a level of concern. Further, when the mist recovery rate calculated by the analysis is 86 [%], it becomes difficult to find the mist M adhering to the continuous paper P.

In the analysis, the transport speed of the continuous paper P is 100 [m / min], the blow speed of the air blown from the outlet is 3 [m / s], and the suction speed of the air sucked from the suction port is set. It was set to 1 [m / s], and the distance L1 from the facing surface 52A to the continuous paper P was set to 1 [mm].

-Discussion-
Next, the above-mentioned results will be considered. When the distance L2 from the outlet 56 to the suction port 60 is long, it is considered that the amount of air blown out from the outlet 56 and sucked from the suction port 60 is smaller than that when the distance L2 is short. This is because when the distance L2 is long, the frictional force generated between the air per unit flow rate flowing from the outlet 56 to the suction port 60 and the facing surface 52A is larger than when the distance L2 is short. be. Therefore, when the distance L2 from the outlet 56 to the suction port 60 is long, the amount of air flowing from the outlet 56 to the suction port 60 is smaller than when the distance L2 is short, and the mist recovery rate is low. Become.

As can be seen from the table shown in FIG. 6, when the mist recovery rate is taken into consideration, when the distance L1 from the facing surface 52A to the continuous paper P is 1 [mm], the distance L2 is 10 [mm] or less. It is preferable, 6 [mm] or less is more preferable.

Here, as described above, the difference in the mist recovery rate occurs when the distance L2 is long and the air per unit flow rate flowing from the outlet 56 to the suction port 60 as compared with the case where the distance L2 is short. This is because the frictional force generated between the facing surface 52A and the facing surface 52A becomes large. Therefore, when the distance L1 from the facing surface 52A to the continuous paper P becomes long, the frictional force generated between the air per unit flow rate flowing from the outlet 56 to the suction port 60 and the facing surface 52A becomes small. In this analysis, when the distance L1 is 1 [mm], the distance L2 is preferably 10 [mm] or less, and more preferably 6 [mm] or less. That is, the distance L2 is preferably 10 times or less the distance L1 from the facing surface 52A to the continuous paper P, and more preferably 6 times or less the distance L1.

(summary)
As described above, the inclination angle θ1 of the outlet path 58 is 20 [degrees] or more and 60 [degrees] or less. Therefore, the mist recovery rate is higher than when the inclination angle θ1 is larger than 60 [degrees] or smaller than 20 [degrees], so that the mist M is suppressed from adhering to the continuous paper P. Will be done.

Further, the distance L2 from the outlet 56 to the suction port 60 is 10 times or less the distance L1 from the facing surface 52A to the continuous paper P. Therefore, as compared with the case where the distance L2 is larger than 10 times the distance L1, the mist recovery rate is higher, so that the mist M is suppressed from adhering to the continuous paper P.

Further, the suction path 62 extends in the device facing direction when viewed from the device depth direction. Therefore, for example, as shown in FIG. 10, the suction path is blown out from the outlet 56 in the transport direction of the continuous paper P as compared with the case where the suction path is inclined to the upstream side in the transport direction of the continuous paper P. The amount of air that flows to the upstream side and is sucked from the suction port 60 increases. As a result, the mist M is suppressed from adhering to the continuous paper P as compared with the case where the suction path is inclined to the upstream side in the transport direction of the continuous paper P.

Further, the air blown out from the outlet 56 flows between the facing surface 52A and the continuous paper P, is sucked in from the suction port 60, passes through the filter 48 and the fan 46, and is blown out again from the outlet 56. Therefore, the number of parts is reduced as compared with the case where the discharge mechanism for discharging air to the outside of the image forming apparatus 10 is used.

Some of the mist M that was not collected by the mist recovery device does not adhere to the continuous paper P and flows while floating to the vicinity of the discharge head 30 on the downstream side. Some may adhere to the surface of the discharge head due to the influence. In that case, not only the maintenance cost such as cleaning increases because the dirt on the surface of the ejection head accelerates, but also the droplet ejection accuracy from the ejection head 30 deteriorates or the droplet ejection is caused by the attached mist M. It may interfere with itself and deteriorate the print quality. Improving the mist recovery rate also has the effect of preventing these troubles.

Further, in the mist recovery device of the present invention, most of the air blown out from the outlet 56 travels to the upstream side and is sucked from the suction port 60. I hardly go. When the amount of air coming out of the outlet 56 and heading downstream increases, the flight accuracy and landing position accuracy of the droplets ejected from the ejection head 30 deteriorate due to the extra wind speed, and the print quality deteriorates. There is. The mist recovery device of the present invention also has an effect of preventing these troubles.

<Second Embodiment>
An example of the image forming apparatus according to the second embodiment of the present invention will be described with reference to FIG. The image forming apparatus of the second embodiment will be mainly described as being different from the image forming apparatus of the first embodiment.

In the mist recovery device 140 provided in the image forming device 110 of the second embodiment, as shown in FIG. 13, the portion between the suction port 60 and the outlet 56 on the facing surface 52A of the mist recovery device 140 is The first facing surface is 154. Further, in the wall surface forming the suction path 62, the wall surface facing the upstream side in the transport direction of the continuous paper P is the upstream wall surface 62A. A flat chamfered portion 158 (so-called C chamfer) is formed on the ridgeline between the first facing surface 154 and the upstream wall surface 62A.

Therefore, as compared with the case where the first facing surface 154, the upstream wall surface 62A, and the corner portion (pin angle) are formed, the distance L2 from the outlet 56 to the suction port 60 is shortened, so that the mist recovery rate is increased. The height is increased, and the mist M is suppressed from adhering to the continuous paper P.

The other actions of the second embodiment are the same as those of the first embodiment.

<Third Embodiment>
An example of the image forming apparatus according to the third embodiment of the present invention will be described with reference to FIG. The image forming apparatus of the third embodiment will be mainly described as being different from the image forming apparatus of the first embodiment.

In the mist recovery device 240 provided in the image forming device 210 of the third embodiment, as shown in FIG. 14, the suction path 262 extends along the blowout path 58 when viewed from the depth direction of the device.

Therefore, as compared with the case where the suction path extends in the direction facing the device, the distance L2 from the outlet 56 to the suction port 260 is increased while maintaining the minimum thickness between the suction path 262 and the outlet path 58. It gets shorter. Further, when the distance L2 is shortened, the mist recovery rate is higher than in the case where the suction path extends in the direction facing the device, and the mist M is suppressed from adhering to the continuous paper P.

<Fourth Embodiment>
An example of the image forming apparatus according to the fourth embodiment of the present invention will be described with reference to FIG. The image forming apparatus of the fourth embodiment will be mainly described as being different from the image forming apparatus of the first embodiment.

In the mist recovery device 340 provided in the image forming apparatus 310 of the fourth embodiment, as shown in FIG. 15, the portion between the suction port 60 and the outlet 56 on the facing surface 52A of the mist recovery device 340 is It is said to be the first facing surface 354. Further, in the facing surface 52A, the upstream portion of the continuous paper P with respect to the suction port 60 in the transport direction is the second facing surface 358. The distance from the second facing surface 358 to the continuous paper P (L10 in FIG. 15) is longer than the distance from the first facing surface 354 to the continuous paper P (L11 in FIG. 15). In the present embodiment, the distance L11 is the same distance as the distance L1 of the first embodiment.

Further, the wall surface that forms the suction path 62 and faces the downstream side in the transport direction of the continuous paper P is the downstream wall surface 62B. A flat chamfered portion 362 (so-called C chamfer) is formed on the ridgeline between the second facing surface 358 and the downstream wall surface 62B.

In this configuration, in the mist M flowing while floating in the air from the upstream side to the downstream side in the transport direction of the continuous paper P, the portion separated from the continuous paper P is blocked by the wall surface forming the suction path 62 (FIG. FIG. Middle part J4). The blocked mist M flows through the suction port 60 to the suction path 62.

Therefore, the mist recovery rate is higher than in the case where the distance from the second facing surface to the continuous paper P is the same as the distance from the first facing surface to the continuous paper P, so that the mist M is generated in the continuous paper P. Adhesion is suppressed.

Further, a chamfered portion 362 is formed on the ridgeline between the second facing surface 358 and the downstream wall surface 62B. Therefore, the amount of mist M blocked by the wall surface forming the suction path 62 is larger than that in the case where the corner portion (pin angle) is formed between the second facing surface and the downstream wall surface. As a result, the mist recovery rate is increased, and the mist M is suppressed from adhering to the continuous paper P.

Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments can be taken within the scope of the present invention. That is clear to those skilled in the art. For example, in the above embodiment, the blowing direction of the air blown from the outlet 56 is changed by changing the inclination angle of the blowing path 58, but the blowing direction of the air is changed by arranging fins or the like at the blowing port. You may change it.

Further, in the above embodiment, the distance L2 from the outlet 56 to the suction port 60 is 10 times or less the distance L1 from the facing surface 52A to the continuous paper P, but the distance L2 is larger than 10 times the distance L1. You may. However, in this case, the equivalent effect achieved by setting the distance L2 to 10 times or less the distance L1 is not exhibited.

Further, the chamfered portion formed on the ridge line in the second embodiment and the fourth embodiment is C chamfered, but may be R chamfered, for example.

Further, in the above embodiment, each embodiment has been described using the image forming apparatus 10, 110, 210, 310 for forming an image on the continuous paper P, but it is an image forming apparatus for forming an image on a sheet of paper. May be good.

Further, in the above embodiment, the support member 80 and the droplet ejection head 30 are separate bodies, but the member on which the facing surface 80A of the support member 80 is formed and the nozzle surface 32 of the droplet ejection head 30 are formed. The formed member may be integrally formed.

Further, in the above embodiment, the support member 80 and the mist recovery devices 40, 140, 240, 340 are separate bodies, but the members exposed by the facing surface 80A of the support member 80 and the mist recovery devices 40, 140, The member on which the facing surfaces 52A of 240 and 340 are formed may be integrally formed.

Further, although not particularly described in the above embodiment, the blowing speed of the air blown out from the outlet 56 may be changed according to the conveying speed of the continuous paper P.

Further, although not particularly described in the above embodiment, when the width of the outlet path differs between the lower end and the upper end, as shown in FIG. 16, a line connecting the center of the lower end and the center of the upper end is used. , Measure the tilt angle of the outlet.

Further, in the above embodiment, the mist recovery device 40 is also arranged on the downstream side of the droplet ejection head 30Y in the transport direction of the continuous paper P, but the mist recovery device 40 is a liquid adjacent to each other in the transport direction of the continuous paper P. It suffices if it is arranged between the drop ejection heads 30.

10 Image forming device 30 Droplet ejection head 32 Nozzle surface 40 Mist recovery device 52A Facing surface (an example of another facing surface)
56 Outlet 58 Outlet passage 60 Suction port 62 Suction passage 62A Upstream wall surface 62B Downstream wall surface 80 Support member (example of suppression member)
80A Facing surface 110 Image forming device 140 Mist collecting device 154 First facing surface 158 Chamfering part 210 Image forming device 240 Mist collecting device 260 Suction port 262 Suction path 310 Image forming device 340 Mist collecting device 354 First facing surface 358 Second facing Surface 362 Chamfered part

Claims (9)

A plurality of droplet ejection heads having a nozzle surface formed with a plurality of nozzles for ejecting droplets toward the recording medium and arranged at intervals in the transport direction of the recording medium, and a plurality of droplet ejection heads.
An outlet that is arranged between the adjacent droplet ejection heads in the transport direction of the recording medium and blows air toward the recording medium, and an outlet that blows out from the outlet on the upstream side of the outlet in the transport direction of the recording medium. It has a suction port for sucking the air to be sucked together with the mist of the droplets, and the blowing direction of the air blown out from the outlet is inclined to the downstream side in the transport direction of the recording medium when viewed from the width direction of the recording medium. , A mist recovery device with an inclination angle of 20 [degrees] or more and 60 [degrees] or less,
The droplet mist is arranged between the adjacent droplet ejection heads and the mist collecting device in the transport direction of the recording medium to form a facing surface facing the transported recording medium, and the droplet mist is ejected. A restraining member for suppressing entry between the head and the mist collecting device is provided.
The mist collecting device is
Including the other facing surface facing the recording medium and formed with the outlet and the suction port, the air sucked from the suction port flows, and the upstream wall surface facing the upstream side in the transport direction of the recording medium is included. With a formed suction path,
In the other facing surface, the portion between the suction port and the air outlet is defined as the first facing surface.
An image forming apparatus in which a chamfered portion is formed on a ridge line formed by the first facing surface and the upstream wall surface . It has a nozzle surface on which a plurality of nozzles for ejecting droplets toward the recording medium facing the conveyed recording medium are formed, and a plurality of droplets are ejected at intervals in the conveying direction of the recording medium. With the head
An outlet that is arranged between the adjacent droplet ejection heads in the transport direction of the recording medium and blows air toward the recording medium, and an outlet that blows out from the outlet on the upstream side of the outlet in the transport direction of the recording medium. It has a suction port for sucking the air to be sucked together with the mist of the droplets and a blowout path through which the air blown out from the blowout port flows, and the blowout path conveys the recording medium when viewed from the width direction of the recording medium. A mist recovery device that tilts downstream in the direction and has an inclination angle of 20 [degrees] or more and 60 [degrees] or less.
The droplet mist is arranged between the adjacent droplet ejection heads and the mist collecting device in the transport direction of the recording medium to form a facing surface facing the transported recording medium, and the droplet mist is ejected. A restraining member for suppressing entry between the head and the mist collecting device is provided.
The mist collecting device is
Including the other facing surface facing the recording medium and formed with the outlet and the suction port, the air sucked from the suction port flows, and the upstream wall surface facing the upstream side in the transport direction of the recording medium is included. With a formed suction path,
In the other facing surface, the portion between the suction port and the air outlet is defined as the first facing surface.
An image forming apparatus in which a chamfered portion is formed on a ridge line formed by the first facing surface and the upstream wall surface . A plurality of droplet ejection heads having a nozzle surface formed with a plurality of nozzles for ejecting droplets toward the recording medium and arranged at intervals in the transport direction of the recording medium, and a plurality of droplet ejection heads.
An outlet that is arranged between the adjacent droplet ejection heads in the transport direction of the recording medium and blows air toward the recording medium, and an outlet that blows out from the outlet on the upstream side of the outlet in the transport direction of the recording medium. It has a suction port for sucking the air to be sucked together with the mist of the droplets, and the blowing direction of the air blown out from the outlet is inclined to the downstream side in the transport direction of the recording medium when viewed from the width direction of the recording medium. , A mist recovery device with an inclination angle of 20 [degrees] or more and 60 [degrees] or less,
The droplet mist is arranged between the adjacent droplet ejection heads and the mist collecting device in the transport direction of the recording medium to form a facing surface facing the transported recording medium, and the droplet mist is ejected. A restraining member for suppressing entry between the head and the mist collecting device is provided.
The mist recovery device faces the recording medium and has another facing surface on which the outlet and the suction port are formed.
In the other facing surface, the portion between the suction port and the outlet is the first facing surface, and the portion upstream of the suction port in the transport direction of the recording medium is the second facing surface. ,
An image forming apparatus in which the distance from the second facing surface to the recording medium is longer than the distance from the first facing surface to the recording medium . It has a nozzle surface on which a plurality of nozzles for ejecting droplets toward the recording medium facing the conveyed recording medium are formed, and a plurality of droplets are ejected at intervals in the conveying direction of the recording medium. With the head
An outlet that is arranged between the adjacent droplet ejection heads in the transport direction of the recording medium and blows air toward the recording medium, and an outlet that blows out from the outlet on the upstream side of the outlet in the transport direction of the recording medium. It has a suction port for sucking the air to be sucked together with the mist of the droplets and a blowout path through which the air blown out from the blowout port flows, and the blowout path conveys the recording medium when viewed from the width direction of the recording medium. A mist recovery device that tilts downstream in the direction and has an inclination angle of 20 [degrees] or more and 60 [degrees] or less.
The droplet mist is arranged between the adjacent droplet ejection heads and the mist collecting device in the transport direction of the recording medium to form a facing surface facing the transported recording medium, and the droplet mist is ejected. A restraining member for suppressing entry between the head and the mist collecting device is provided.
The mist recovery device faces the recording medium and has another facing surface on which the outlet and the suction port are formed.
In the other facing surface, the portion between the suction port and the outlet is the first facing surface, and the portion upstream of the suction port in the transport direction of the recording medium is the second facing surface. ,
An image forming apparatus in which the distance from the second facing surface to the recording medium is longer than the distance from the first facing surface to the recording medium . The mist recovery device has a suction path formed by including a downstream wall surface facing the downstream side in the transport direction of the recording medium while flowing air sucked from the suction port.
The image forming apparatus according to claim 3 or 4, wherein a chamfered portion is formed on the ridgeline between the second facing surface and the downstream wall surface. The mist recovery device faces the recording medium and has another facing surface on which the outlet and the suction port are formed.
If the distance from the other facing surface to the recording medium is L1 and the distance from the outlet to the suction port in the transport direction of the recording medium is L2, the following formula ( 1 ) holds. The image forming apparatus according to any one of 5 .
L2 ≤ L1 × 10 ... (1) The mist collecting device is
With respect to the other facing surface facing the recording medium and formed with the outlet and the suction port.
It has a suction path through which air sucked from the suction port flows.
Claims 1 to 6 say that the suction path extends in the direction facing the other facing surface of the recording medium when viewed from the width direction of the recording medium, or is inclined to the downstream side in the transport direction of the recording medium. The image forming apparatus according to any one of the above items. The mist recovery device has an outlet through which air blown from the outlet flows.
The image forming apparatus according to claim 7 , wherein the suction path extends along the blowout path when viewed from the width direction of the recording medium. The mist recovery device faces the recording medium and has another facing surface on which the outlet and the suction port are formed.
Claims 1 to 8 that air blown out from the outlet is flown between the other facing surface and the recording medium, sucked in from the suction port, captures the mist contained in the air, and blown out again from the outlet. The image forming apparatus according to any one of the above items.

Images