JP7490990B2 - Inkjet recording device and recording medium transport device - Google Patents

Description

The present invention relates to an inkjet recording device and a recording medium transport device.

Inkjet recording devices form (record) images by transporting a recording medium on the drum body of a drum unit and ejecting ink droplets from an inkjet head onto the recording medium transported to the drum unit. The drum body also sucks the recording medium to prevent it from coming into contact with the inkjet head. When an inkjet recording device is used for an image formation process for a long period of time, the temperature of the drum body rises. As a result, the temperature of the recording medium transported by the drum body rises, causing image defects.

One way to control the temperature of the drum body is to use a method such as that described in Patent Document 1. Patent Document 1 describes a technique for lowering the temperature of the surface of the drum body by blowing air onto the surface to cool it.

JP 2011-62988 A

However, with the technology described in Patent Document 1, wind is blown onto the drum body from the outside, so only a portion of the surface of the drum body is cooled, causing temperature differences (temperature unevenness) on the surface of the drum body. As a result, with the technology described in Patent Document 1, temperature unevenness also occurs in the recording medium transported by the drum body, causing unnecessary images.

In view of the above-mentioned problems, the present invention aims to provide an inkjet recording device and a recording medium transport device that can reduce temperature unevenness on the surface of the drum body.

To solve the above problems and achieve the object of the present invention, the inkjet recording device of the present invention is equipped with a drum unit that transports a recording medium. The drum unit is equipped with a drum body that has multiple suction holes and holds the recording medium by adsorbing it to its surface, and a temperature control unit that is provided inside the drum body and adjusts the temperature of the drum body.

The recording medium transport device of the present invention also includes a drum body having multiple suction holes that adsorbs and holds the recording medium on its surface, and a temperature control unit that is provided inside the drum body and adjusts the temperature of the drum body.

The inkjet recording device and recording medium transport device configured as above can reduce temperature unevenness on the surface of the drum body.

1 is an overall configuration diagram showing an inkjet recording apparatus according to a first embodiment of the present invention; 1 is a cross-sectional view of a drum unit in an inkjet recording apparatus according to a first embodiment of the present invention, taken along an axial direction. 1 is an explanatory diagram showing a drum main body and a connection plate in an inkjet recording device according to a first embodiment of the present invention; 3 is a cross-sectional view taken along line AA in FIG. 2. 1 is an explanatory diagram showing an outer circumferential surface portion, which is the surface of a drum main body, in an inkjet recording device according to a first embodiment of the present invention; 2 is a diagram showing the inside of a suction chamber in the inkjet recording apparatus according to the first embodiment of the present invention; FIG. 3 is a diagram showing a passage path of a coolant in the inkjet recording apparatus according to the first embodiment of the present invention; FIG. 8A and 8B are explanatory diagrams showing an example of the operation of the drum unit in the inkjet recording apparatus according to the first embodiment of the present invention, with FIG. 8A showing the operation during transport of the recording medium and FIG. 8B showing the air blowing operation. 5 is a flowchart showing a temperature adjustment (temperature control) operation of a drum body in the inkjet recording apparatus according to the first embodiment of the present invention. 11 is a cross-sectional view of a ram unit in an ink jet recording apparatus according to a second embodiment of the present invention, taken along the axial direction. FIG. 11 is a cross-sectional view taken along line BB shown in FIG.

Below, an embodiment of the present invention will be described with reference to Figs. 1 to 11. Note that common members in each figure are given the same reference numerals.

1. First embodiment 1-1. Configuration example of inkjet recording apparatus First, a configuration example of an inkjet recording apparatus according to a first embodiment of the present invention (hereinafter, referred to as "this example") will be described with reference to FIG.
FIG. 1 is a schematic diagram showing the overall configuration of an inkjet recording apparatus.

The inkjet recording device 1 shown in FIG. 1 forms (records) an image on paper by ejecting ink from nozzles provided on an inkjet head. This inkjet recording device 1 is a color inkjet recording device that overlays four colors of ink: yellow (Y), magenta (M), cyan (C), and black (Bk).

The inkjet recording device 1 has a paper feed section 10, a paper supply section 12, an image forming section 20, and a paper discharge section 30. The inkjet recording device 1 forms image data input from an external device onto paper P.

The paper feed unit 10 has a paper feed tray 11. The paper feed tray 11 is a plate-shaped member on which paper P, which is an example of a recording medium, can be placed. The paper feed tray 11 is arranged so that it can move vertically depending on the number of sheets of paper P placed on it. Of the multiple sheets of paper P placed on the paper feed tray 11, the topmost sheet P in the vertical direction is held in a position where it can be transported by the paper supply unit 12.

The paper supply unit 12 is disposed between the paper feed unit 10 and the image forming unit 20. The paper supply unit 12 has a transfer roller 12a. The paper supply unit 12 transports the topmost paper P placed on the paper feed tray 11 toward the image forming unit 20, and transfers the paper P to a drum unit 22 of the image forming unit 20, which will be described later, via the transfer roller 12a.

The image forming unit 20 is a component that forms an image on paper P. The image forming unit 20 has multiple carriages 21Y, 21M, 21C, and 21K, a drum unit 22, a fixing unit 23, a paper discharge unit 26, and an inversion unit 25. The image forming unit 20 also has a temperature sensor 27 and a control unit (not shown).

The drum unit 22 receives the paper P from the paper supply section 12 and transports the paper P toward the paper discharge section 26. A plurality of carriages 21Y, 21M, 21C, and 21K and a fixing section 23 are arranged on the outer peripheral surface of the drum unit 22. The detailed configuration of the drum unit 22 will be described later.

The multiple carriages 21Y, 21M, 21C, and 21K are supported by a support portion (not shown) and face the outer peripheral surface of the drum unit 22. The multiple carriages 21Y, 21M, 21C, and 21K each have an inkjet head that forms an image on the paper P using ink of a corresponding color.

Specifically, the inkjet head of the first carriage 21Y forms an image using yellow (Y) ink. The inkjet head of the second carriage 21M forms an image using magenta (M) ink, and the inkjet head of the third carriage 21C forms an image using cyan (C) ink. And the inkjet head of the fourth carriage 21K forms an image using black (K) ink. In addition, the inkjet recording device 1 of this example uses ultraviolet curing ink.

The carriages 21Y, 21M, 21C, and 21K are arranged at intervals in the circumferential direction of the drum unit 22 at the top and bottom of the drum unit 22. In the inkjet recording device 1 of this example, the image forming section 20 is provided with four carriages 21Y, 21M, 21C, and 21K to form an image using four colors of ink, but the number of carriages is not limited to four. The number of carriages may be four or less, or more than four.

The fixing unit 23 is disposed downstream of the four carriages 21Y, 21M, 21C, and 21K in the transport direction. For example, a fluorescent tube that irradiates ultraviolet light, such as a low-pressure mercury lamp, is used as the fixing unit 23. The fixing unit 23 irradiates the ultraviolet light onto the paper P transported by the drum unit 22, and hardens the ink ejected onto the paper P. In this way, the fixing unit 23 fixes the image formed on the paper P.

Fluorescent tubes that emit ultraviolet light include low-pressure mercury lamps, mercury lamps with operating pressures of several hundred Pa to 1 MPa, light sources that can be used as germicidal lamps, cold cathode fluorescent lamps, ultraviolet laser light sources, metal halide lamps, and light-emitting diodes. Of these, light sources that can irradiate ultraviolet light at a higher illuminance and consume less power (such as light-emitting diodes) are more desirable.

The fixing unit 23 is not limited to irradiating ultraviolet rays, but may be any unit that irradiates energy rays that have the property of hardening the ink depending on the properties of the ink, and the light source is also replaced depending on the wavelength of the energy rays. The fixing unit 23 is also not limited to irradiating light such as ultraviolet rays. As a fixing unit, for example, various methods can be applied, such as drying the ink by applying heat to the paper or applying a liquid that causes a chemical change to the ink.

When the ink reacts with ultraviolet light and hardens, heat is generated in the ink. The heat generated when the ink hardens causes the temperature of the drum unit 22 to rise. The temperature of the drum unit 22 also rises due to heat from the fixing section 23 and heat generated when the multiple carriages 21Y, 21M, 21C, and 21K eject ink. As a result, uneven temperature occurs on the surface of the drum main body 41 (see Figure 2) that constitutes the drum unit 22, which may result in poor image quality.

To reduce such temperature unevenness in the drum body 41, the inkjet recording device 1 of this example is provided with a mechanism for adjusting the temperature of the drum body 41. The configurations of the drum unit 22 and the drum body 41 will be described later.

The temperature sensor 27 is disposed upstream of the carriages 21Y, 21M, 21C, and 21K in the transport direction. The temperature sensor 27 faces the drum body 41 that constitutes the drum unit 22. The temperature sensor 27 measures the surface temperature of the drum body 41. The temperature information measured by the temperature sensor 27 is output to a control unit (not shown).

In this example, the temperature sensor 27 is disposed upstream of the carriages 21Y, 21M, 21C, and 21K in the transport direction, but this is not limited to this. The temperature sensor 27 may be disposed downstream of the fixing unit 23 in the transport direction, or the temperature sensor 27 may be provided inside the drum main body 41, and the position at which the temperature sensor 27 is disposed is not limited.

The control unit controls a temperature adjustment unit 55 provided in the drum unit 22, which will be described later, based on the temperature information output from the temperature sensor 27. The control unit may be a control unit that controls the entire inkjet recording device 1, or a control unit that controls only the image forming unit 20 and the drum unit 22.

The paper discharge section 26 is disposed downstream of the fixing section 23 in the transport direction. The paper discharge section 26 has a plurality of transport rollers 26a, 26b. The paper discharge section 26 receives the paper P from the drum unit 22 by the plurality of transport rollers 26a, 26b, and transports it toward the paper discharge section 30. The paper discharge section 26 also has a reversing section 25. The reversing section 25 is a section that reverses the paper P from front to back in order to form images on both sides of the paper P.

The paper discharge section 30 stores the paper P sent from the image forming section 20 by the paper discharge section 26. The paper discharge section 30 has a flat paper discharge tray 31. The paper discharge section 30 places the paper P on which an image has been formed on the paper discharge tray 31.

1-2. Structure of the Drum Unit Next, the structure of the drum unit 22 will be described with reference to FIGS.
FIG. 2 is a cross-sectional view of the drum unit 22 taken along the axial direction.

As shown in FIG. 2, the drum unit 22, which represents a recording medium transport device, has a drum body 41, a connection plate 42, a rotating shaft 43, and a pair of bearing plates 44, 44. The drum unit 22 also has a blower 45 and a drive unit 46.

The drum body 41 has a hollow interior 41a formed in a generally cylindrical shape. The drum body 41 is provided with a rotating shaft 43. The rotating shaft 43 penetrates the drum body 41 from one axial end to the other axial end along the axial direction of the drum body 41. The rotating shaft 43 is rotatably supported by a bearing plate 44. A driving unit 46 is provided at one axial end of the rotating shaft 43. When the driving unit 46 is driven, the rotating shaft 43 and the drum body 41 rotate.

The rotating shaft 43 is formed of a hollow pipe. A refrigerant R1, which is a heat medium for temperature adjustment, passes through the cylindrical hole 43a of the rotating shaft 43 via a chiller 81 (see FIG. 7). The refrigerant R1 is introduced from the opposite side of the rotating shaft 43 to the drive unit 46. For example, air or water is used as the refrigerant R1. In this way, by using the rotating shaft 43 as a pipe through which the refrigerant R1 passes, there is no need to install a new pipe through which the refrigerant R1 passes, which reduces the number of parts and simplifies the configuration of the drum unit 22.

The rotating shaft 43 is formed with a first branch portion 43b and a second branch portion 43c. The first branch portion 43b and the second branch portion 43c are connected to the cylindrical hole 43a. The first branch portion 43b and the second branch portion 43c are formed inside the drum body 41 of the rotating shaft 43. The first branch portion 43b is disposed on the upstream side where the refrigerant R1 passes, and the second branch portion 43c is disposed on the downstream side where the refrigerant R1 passes. The first branch portion 43b and the second branch portion 43c are connected to a temperature control pipe 56 provided in the drum body 41, which will be described later. The detailed configuration of the drum body 41 will be described later.

A connection plate 42 is disposed at the other axial end of the drum body 41, i.e., the end opposite the drive unit 46. The connection plate 42 is disposed between the drum body 41 and a bearing plate 44 disposed at the other axial end of the drum body 41. The connection plate 42 is biased toward the drum body 41 by a biasing member 65 provided on the bearing plate 44.

FIG. 3 is an explanatory diagram showing the drum body 41 and the connection plate 42.
2 and 3, the connection plate 42 is formed in a substantially circular plate shape. The connection plate 42 is formed with a connection slit 61 and an insertion hole 62. The insertion hole 62 is a through hole that passes through the connection plate 42 from one end to the other end in the axial direction. The rotation shaft 43 is inserted into the insertion hole 62.

The connection slit 61 is formed on one surface of the connection plate 42 facing the drum body 41. The connection slit 61 is an arc-shaped groove. When the drum body 41 rotates, the connection slit 61 faces a connection hole 54 provided in the drum body 41, which will be described later. When the connection slit 61 faces the connection hole 54, the connection slit 61 and the connection hole 54 communicate with each other. In addition, a pipe 71 leading from the blower 45 is fixed to the connection plate 42. The pipe 71 communicates with the connection slit 61.

The connection slit 61 may be formed in a ring shape so that the connection slit 61 and the connection hole 54 always face each other.

Next, the detailed structure of the drum body 41 will be described with reference to FIGS.
FIG. 4 is a cross-sectional view taken along line AA shown in FIG.
2 and 3 , the drum body 41 has an outer peripheral surface portion 51, a plurality of (three in this example) suction chambers 52, suction piping 53, and a temperature adjustment portion 55 that adjusts the temperature. The outer peripheral surface portion 51 covers the outer peripheral surface of the drum body 41 along the circumferential direction of the drum body 41.

FIG. 5 is an explanatory diagram showing an outer peripheral surface portion 51 which is the surface of the drum main body 41.
5, a large number of suction holes 51a are formed in the outer peripheral surface portion 51. Alternatively, the suction holes 51a may be provided only in the portion of the outer peripheral surface portion 51 facing the suction chamber 52.

The suction chambers 52 are formed on the outer peripheral surface of the drum body 41. The suction chambers 52 are arranged at intervals along the circumferential direction of the drum body 41. The suction chambers 52 are spaces recessed radially inward from the outer peripheral surface of the drum body 41. The suction chambers 52 are covered by the outer peripheral surface portion 51.

The suction chamber 52 is formed with a suction port 52a, and a connection hole 54 is formed on the surface of the drum body 41 that faces (slides against) the connection plate 42. The suction pipe 53 is disposed inside the drum body 41 41a. One end of the suction pipe 53 is connected to the suction port 52a, and the other end of the suction pipe 53 is connected to the connection hole 54.

When the connection hole 54 faces the connection slit 61 of the connection plate 42, the blower 45, the piping 71, the connection slit 61, the connection hole 54, the suction piping 53 and the suction port 52a are connected.

The temperature control unit 55 is disposed in the interior 41a of the drum body 41. That is, the temperature control unit 55 is disposed radially inward of the drum body 41 from the suction chamber 52. The temperature control unit 55 has a temperature control pipe 56. One end of the temperature control pipe 56 is connected to the first branch 43b, and the other end is connected to the second branch 43c. The temperature control pipe 56 extends radially outward from the first branch 43b and the second branch 43c, and is disposed so as to surround the suction pipe 53. The temperature control pipe 56 is disposed near the suction chamber 52 and the inner wall surface of the interior 41a of the drum body 41, i.e., the outer peripheral surface.

The refrigerant R1 is introduced into the temperature control pipe 56 from the first branch 43b of the rotating shaft 43. The refrigerant R1 that has passed through the temperature control pipe 56 returns to the cylindrical hole 43a of the rotating shaft 43 via the second branch 43c. As the refrigerant R1 passes through the temperature control pipe 56, the temperature of the suction chamber 52 and the outer peripheral surface of the drum body 41 can be adjusted (cooled) by the refrigerant R1. In this way, by providing the temperature control unit 55 inside 41a of the drum body 41, it is possible to reduce temperature unevenness on the surface (outer peripheral surface) of the drum body 41 compared to when the temperature is adjusted from the outside of the drum body 41.

As described above, the refrigerant R1 is introduced from the side of the rotating shaft 43 opposite the drive unit 46. This makes it possible to prevent the temperature of the refrigerant R1 from rising due to heat generated by the drive unit 46 being driven before the refrigerant R1 passes through the temperature adjustment unit 55. In addition, when the drive unit 46 is driven, the transmission mechanism of the drive unit 46 causes a flow of outside air, which has an effect similar to air cooling. Therefore, there is a risk of a temperature difference occurring between the drive unit 46 side and the opposite side of the drum body 41. In response to this, by introducing the refrigerant R1 from the opposite side of the drive unit 46, the temperature difference caused by the drive unit 46 can be reduced.

In addition, a space consisting of the suction chamber 52 is formed on the outer peripheral surface of the drum body 41. Therefore, the layer of air formed by the suction chamber 52 inhibits the transfer of heat by the temperature adjustment unit 55. As a result, the effect of the temperature adjustment of the surface of the drum body 41 by the temperature adjustment unit 55 is reduced.

The temperature adjustment unit 55 also has a heater (not shown) that heats the drum body 41. The heater is disposed near the suction chamber 52. The temperature adjustment unit 55 adjusts the temperature of the drum body 41 by heating or cooling the drum body 41 under the control of the control unit. When heating the drum body 41, the heater is driven, and when cooling the drum body 41, refrigerant R1 is passed through the temperature adjustment pipe 56.

In the above-described embodiment, the refrigerant R1 is used as a heat medium to be introduced into the temperature adjustment unit 55 and the rotating shaft 43 to cool the drum body 41, but this is not limited to the above. For example, when heating the drum body 41, the drum body 41 may be heated by introducing a heat medium that increases the temperature as a heat medium to be introduced into the temperature adjustment unit 55 and the rotating shaft 43.

FIG. 6 is a diagram showing the inside of the suction chamber 52. As shown in FIG.
To address the above-mentioned problems, as shown in Fig. 6, a plurality of ribs 58 are provided inside the suction chamber 52. The ribs 58 are protrusions that protrude radially outward from the bottom surface of the suction chamber 52. One end of the ribs 58 contacts the bottom surface of the suction chamber 52, and the other end contacts the outer circumferential surface 51. This allows heat transfer between the temperature adjustment unit 55 and the surface of the drum main body 41 through the ribs 58, thereby improving the effect of temperature adjustment of the surface of the drum main body 41 by the temperature adjustment unit 55.

In addition, since the side wall portion 52b of the suction chamber 52 contacts the outer peripheral surface portion 51, the heat transfer efficiency (cooling efficiency) is higher than that of the center portion of the suction chamber 52. Therefore, the multiple ribs 58 are arranged at a position away from the side wall portion 52b where the heat transfer efficiency is high. In addition, it is preferable to arrange the multiple ribs 58 more at the suction port 52a, which is the center portion of the suction chamber 52, than at the side wall portion 52b. As a result, the surface area of the entire multiple ribs 58 is larger on the center side of the suction chamber 52 than on the side wall portion 52b side of the suction chamber 52. As a result, the heat transfer efficiency at the center portion and the side wall portion 52b of the suction chamber 52 can be made uniform, and the temperature unevenness on the surface of the drum body 41 can be reduced.

In the inkjet recording device 1 of this example, the number of ribs 58 is changed to change the surface area of the ribs 58 on the central side and the side wall 52b side of the suction chamber 52, but this is not limiting. For example, the surface area of the ribs 58 may be made larger on the central side than on the side wall 52b side by changing the shape and size of the ribs 58 on the central side and the side wall 52b side of the suction chamber 52.

The ribs 58 are positioned so as not to face the suction holes 51a provided in the outer peripheral surface portion 51. Furthermore, the ribs 58 are positioned so as not to impede the flow of air during suction. This makes it possible to prevent the ribs 58 from reducing the suction force of the suction chamber 52 on the paper P.

The shape of the rib 58 can be a rectangular prism, a cylinder, or various other shapes.

In addition, although an example in which a hollow pipe is used as the rotating shaft 43 in this example has been described, the present invention is not limited to this. For example, the rotating shaft 43 may be formed as a solid shaft with a solid interior from the first branch portion 43b to the second branch portion 43c, and the portion of the rotating shaft 43 extending axially outward from the first branch portion 43b and the second branch portion 43c may be formed as a hollow shaft through which the refrigerant R1 can pass.

Furthermore, in this example, an example in which three suction chambers 52 are provided has been described, but this is not limited to this, and three or less suction chambers 52 or more than three suction chambers 52 may be provided.

1-3. Path of Coolant Flow Next, the path of the coolant flow in the inkjet recording apparatus 1 having the above-mentioned configuration will be described with reference to FIG.
FIG. 7 is an explanatory diagram showing the passage path of the refrigerant.

As shown in FIG. 7, refrigerant R1 is first sent from chiller 81, which is a heat medium circulating device, to drum body 41. Then, after cooling drum body 41, refrigerant R1 is sent from drum body 41 to fixing section 23. Then, refrigerant R1 cools fixing section 23 and returns to chiller 81. Then, refrigerant R1 that has returned to chiller 81 is cooled by chiller 81 and sent back to drum body 41.

Here, like the drum body 41, the fixing section 23 also rises in temperature as the image formation process continues, and so cooling is required. The amount of heat used to cool the fixing section 23 is greater than the amount of heat used to cool the drum body 41. Therefore, if the refrigerant R1 is introduced into the fixing section 23 first, the temperature of the refrigerant R1 rises and the drum body 41 cannot be cooled. In contrast, by sending the refrigerant R1 to the drum body 41 first as described above, the fixing section 23 can be sufficiently cooled even if the temperature of the refrigerant R1 becomes higher due to the drum body 41.

1-4 Example of Suction Operation Next, an example of the suction operation of the drum unit 22 in the inkjet recording apparatus 1 having the above-described configuration will be described with reference to FIGS. 8A and 8B.
8A and 8B are explanatory diagrams showing an example of the operation of the drum unit 22. FIG.

As shown in FIG. 8A, when the paper P is transported, air is sucked in by the blower 45 (see FIG. 2). When the connection hole 54 faces the connection slit 61 of the connection plate 42, the blower 45, piping 71, connection slit 61, connection hole 54, suction piping 53, and suction port 52a are connected. As a result, the suction pressure (negative pressure) generated by the blower 45 is propagated through the piping 71, connection slit 61, connection hole 54, suction piping 53, and suction port 52a, and the air pressure inside the suction chamber 52 decreases.

When the air pressure inside the suction chamber 52 drops, i.e., becomes negative pressure, the suction chamber 52 sucks the paper P placed on the surface of the outer peripheral surface portion 51 through the suction holes 51a of the outer peripheral surface portion 51. As a result, the paper P is adsorbed and held on the surface of the drum body 41, which is the outer peripheral surface portion 51 of the drum body 41. As a result, the paper P can be prevented from floating up from the surface of the drum body 41, and the paper P can be prevented from contacting the carriages 21Y, 21M, 21C, 21K, etc.

When paper P is not on the drum unit 22, air is sent from the blower 45 to the pipe 71. Then, the air from the blower 45 is sent to the suction chamber 52 via the pipe 71, the connection slit 61, the connection hole 54, the suction pipe 53, and the suction port 52a. As a result, as shown in FIG. 8B, air is discharged from the suction chamber 52 and the suction hole 51a of the outer peripheral surface portion 51 toward the outside of the drum body 41.

As shown in Figures 2 and 4, the temperature control pipe 56 is arranged to surround the suction pipe 53. This allows the refrigerant R1 flowing through the temperature control pipe 56 to cool the air passing through the suction pipe 53, thereby cooling the suction chamber 52 and the outer peripheral surface portion 51. As a result, the surface temperature of the drum body 41 can be lowered.

In addition, a suction blower and an air blower may be provided as the blowers, and a suction connection slit and an air connection slit may be formed in the connection plate 42. This allows the suction operation and the air blowing operation to be performed simultaneously, and the paper P can be transported while the temperature of the drum body 41 is lowered by the air blowing operation.

1-5. Temperature Adjustment (Temperature Control) Operation of Drum Main Body Next, an example of the temperature adjustment (temperature control) operation of the drum main body 41 having the above-mentioned configuration will be described with reference to FIG.
FIG. 9 is a flowchart showing the temperature adjustment (temperature control) operation of the drum main body 41 .

As shown in FIG. 9, when a print job is started, the temperature sensor 27 measures the surface temperature of the drum body 41 (step S11). The temperature sensor 27 outputs the measured temperature information to the control unit. Next, the control unit determines whether the temperature of the drum body 41 has reached the target temperature (step S12).

If it is determined in the process of step S12 that the temperature of the drum body 41 has not reached the target temperature (NO in step S12), the control unit controls the temperature adjustment unit 55 to heat the drum body 41 (step S13). The method of heating the drum body 41 by the temperature adjustment unit 55 may be a heater, or a heat medium may be passed through the temperature adjustment pipe 56 as a heat medium.

In addition, if it is determined in the processing of step S12 that the temperature of the drum body 41 has reached the target temperature (YES judgment in step S12), the control unit determines whether the temperature of the drum body 41 has exceeded the target temperature based on the temperature information measured by the temperature sensor 27 (step S14).

If it is determined in the process of step S14 that the temperature of the drum body 41 does not exceed the target temperature (NO judgment in step S14), the process of step S16 described below is performed. On the other hand, if it is determined in the process of step S14 that the temperature of the drum body 41 exceeds the target temperature (YES judgment in step S14), the control unit controls the temperature adjustment unit 55 to flow refrigerant R1 through the temperature adjustment unit 55 (step S15). As a result, the drum body 41 is cooled by the temperature adjustment unit 55.

Next, the control unit determines whether the print job has ended (step S16). If it is determined in step S16 that the print job has not ended (NO in step S16), the process returns to step S12, and the temperature adjustment unit 55 continues adjusting the temperature of the drum body 41. If it is determined in step S16 that the print job has ended (NO in step S16), the temperature adjustment of the drum body 41 is completed. Note that the temperature adjustment described above may be performed not only during execution of the print job, but also from the preparation stage before executing the print job, or during standby between print jobs.

The target temperature may be a constant temperature or may be set to a temperature zone having a predetermined range. If the target temperature is set to a temperature zone having a predetermined range, in the process of step S12, the control unit determines whether the lower limit of the target temperature has been reached, and in the process of step S14, the control unit determines whether the upper limit of the target temperature has been reached.

2. Second Embodiment Next, a drum unit of an inkjet recording apparatus according to a second embodiment will be described with reference to FIGS.
FIG. 10 is a cross-sectional view of a drum unit according to the second embodiment taken along the axial direction, and FIG. 11 is a cross-sectional view taken along the line BB shown in FIG.

The drum unit 22B in this second embodiment differs from the drum unit 22 in the first embodiment in the configuration of the temperature adjustment unit. Therefore, the temperature adjustment unit will be described here, and parts common to the drum unit 22 in the first embodiment will be given the same reference numerals and redundant description will be omitted.

As shown in Figures 10 and 11, the drum unit 22B has a drum body 41B, a connection plate 42, a rotating shaft 43, and a pair of bearing plates 44, 44. The drum unit 22 also has a blower 45 and a drive unit 46. The drum body 41B also has an outer peripheral surface portion 51, multiple (three in this example) suction chambers 52, suction piping 53, and a temperature adjustment unit 55B that adjusts the temperature.

A temperature adjustment unit 55B is disposed in the interior 41a of the drum body 41B. The temperature adjustment unit 55B has multiple Peltier elements 91 and multiple heat sinks 92. The Peltier elements 91 are disposed on the inner wall surface of the interior 41a of the drum body 41B, and are disposed near the outer peripheral surface of the drum body 41B and the suction chamber 52. The multiple Peltier elements 91 are also disposed at intervals in the axial and circumferential directions of the drum body 41B.

Furthermore, the Peltier element 91 is a member in which heat is transferred from one side to the other side when a current flows. The cooling surface of the Peltier element 91 is in contact with the inner wall surface in the interior 41a of the drum main body 41B. As a result, the surface of the drum main body 41B is cooled by the Peltier element 91.

A heat sink 92 is provided on the heating surface, which is the surface of the Peltier element 91 opposite the cooling surface. One end of the heat sink 92 contacts the heating surface of the Peltier element 91, and the other end contacts the outer circumferential surface of the rotating shaft 43. The heat sink 92 transfers heat generated on the heating surface of the Peltier element 91 to the rotating shaft 43. This allows the heating surface of the Peltier element 91 to be cooled by the refrigerant R1 flowing through the rotating shaft 43, and the cooling efficiency of the Peltier element 91 can be improved.

In addition, in the drum unit 22 according to this second embodiment, the rotating shaft 43 is not provided with the first branch portion 43b and the second branch portion 43c.

Other configurations are the same as those of the drum unit 22 in the first embodiment described above, so their description will be omitted. Even in the drum unit 22B having such a temperature adjustment section 55B, it is possible to obtain the same actions and effects as those of the drum unit 22 in the first embodiment described above.

In addition, in the drum unit 22B according to the second embodiment, the cooling surface can be made into a heating surface by changing the direction of the current flowing through the Peltier element 91. This allows the surface of the drum body 41B to be heated by the temperature adjustment unit 55B, making it easy to adjust the temperature of the drum body 41B. In addition, during the temperature adjustment (temperature adjustment) operation of the drum unit 22B, the temperature adjustment unit 55B changes the direction of the current flowing through the Peltier element 91 based on the temperature of the drum body 41B measured by the temperature sensor 27, thereby heating or cooling the drum body 41B so that the temperature of the drum body 41B becomes the target temperature.

The present invention is not limited to the embodiment described above and shown in the drawings, and various modifications are possible without departing from the spirit of the invention described in the claims.

In the above embodiment, an example was described in which paper was used as the recording medium, but this is not limited to this, and various other recording media such as fabric, plastic film, glass plate, and the like can also be used as the recording medium.

In this specification, the words "parallel" and "orthogonal" are used, but these do not mean only "parallel" and "orthogonal" in the strict sense, but also include "parallel" and "orthogonal" and may also mean a "nearly parallel" or "nearly orthogonal" state within a range in which the functions can be exerted.

1...inkjet recording device, 10...paper feed section, 11...paper feed tray, 12...paper supply section, 20...image forming section, 21Y, 21M, 21C, 21K...carriage, 22, 22B...drum unit (recording medium transport device), 23...fixing section, 26...paper discharge section, 27...temperature sensor, 30...paper discharge section, 41, 41B...drum body, 41a...inside, 42...connection plate, 43...rotating shaft, 43a...tube hole, 43b...first branch section, 43c...second branch section, 44...bearing plate, 45...blower (suction section), 46...drive section, 51...outer peripheral surface section, 51a...suction hole, 52...suction chamber, 52a...suction port, 52b...side wall section, 53...suction pipe, 54...connection hole, 55, 55B...Temperature control section, 56...Temperature control pipe, 58...Rib, 61...Connection slit, 62...Through hole, 71...Pipe, 81...Chiller (heat medium circulation device), 91...Peltier element, 92...Heat sink, R1...Refrigerant (heat medium), P...Paper (recording medium)

Claims (10)

A drum unit is provided for conveying a recording medium.
The drum unit includes:
a drum body having a plurality of suction holes and adapted to hold the recording medium by suction on a surface thereof;
a temperature control unit provided inside the drum main body and configured to adjust the temperature of the drum main body;
Equipped with
The drum body is provided with a suction chamber communicating with the suction hole,
the temperature control unit is disposed inside the drum body with respect to the suction chamber,
The suction chamber is a space recessed radially inward from the outer circumferential surface of the drum body,
The drum body is
An outer peripheral surface portion covering the suction chamber and having a plurality of suction holes formed therein;
A plurality of ribs protruding from the bottom surface of the suction chamber toward the outer circumferential surface of the suction chamber are provided.
Inkjet recording device. The inkjet recording device according to claim 1 , wherein the surface area of the ribs arranged on a central portion side of the suction chamber is larger than the surface area of the ribs arranged on a side wall side of the suction chamber. The drum unit includes:
A rotation shaft provided on the drum body;
a bearing that rotatably supports the rotating shaft and the drum body,
The inkjet recording apparatus according to claim 1 , wherein the rotating shaft has a cylindrical hole through which a heat medium used in the temperature adjustment section can pass. The drum unit includes:
A drive unit is provided at one axial end of the rotary shaft and rotates the rotary shaft and the drum body,
The inkjet recording apparatus according to claim 3 , wherein the heat medium is fed into the cylindrical hole from another end of the rotating shaft in the axial direction opposite to the driving portion. a fixing unit disposed downstream of the drum unit in a conveying direction and configured to fix an image formed on the recording medium to the recording medium;
The inkjet recording apparatus according to claim 3 , wherein the heat medium is fed to the drum unit and then to the fixing unit. A suction pipe communicating with the suction hole is provided inside the drum body,
the temperature adjustment unit has a temperature adjustment pipe into which the heat medium is fed through the cylindrical hole of the rotating shaft,
The inkjet recording apparatus according to claim 3 , wherein the temperature control pipe is disposed so as to surround the suction pipe. The temperature control unit is
a Peltier element in contact with an inner wall surface inside the drum body;
The inkjet recording apparatus according to claim 3 , further comprising: a heat sink having one end in contact with the Peltier element and the other end in contact with the rotating shaft. The inkjet recording apparatus according to claim 3 , wherein the heat medium is a refrigerant that cools the drum body. A temperature sensor is provided to measure the temperature of the drum body.
The inkjet recording apparatus according to claim 1 , wherein the temperature adjustment section adjusts the temperature of the drum body based on the temperature of the drum body measured by the temperature sensor. a drum body having a plurality of suction holes and adapted to hold a recording medium by suction on a surface thereof;
a temperature control unit provided inside the drum main body and configured to adjust the temperature of the drum main body;
Equipped with
The drum body is provided with a suction chamber communicating with the suction hole,
the temperature control unit is disposed inside the drum body with respect to the suction chamber,
The suction chamber is a space recessed radially inward from the outer circumferential surface of the drum body,
The drum body is
An outer peripheral surface portion covering the suction chamber and having a plurality of suction holes formed therein;
A plurality of ribs protruding from the bottom surface of the suction chamber toward the outer circumferential surface of the suction chamber are provided.
Recording medium transport device.

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