JP2023144985A - Image forming device - Google Patents

Abstract

To provide an image forming device capable of eliminating electrostatic damage to fans by solving a problem that, if a duct part of a duct unit rubs against the frame during assembly work and electrostatic charging occurs, the fan is also charged due to inductive charging, and electrostatic damage may occur due to discharge when connecting the fan connector.SOLUTION: A duct unit with a fan is provided with ribs to serve as a guide during assembly to thereby suppress fan charging due to sliding friction during assembly and reduce the sliding area to prevent electrostatic damage.SELECTED DRAWING: Figure 8

Description

The present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile machine, or a multifunction device.

2. Description of the Related Art Conventionally, image forming apparatuses have been equipped with a duct unit having a fan and a duct for the purpose of suppressing temperature rise inside the apparatus and discharging heat. In order to prevent the fan from being destroyed by static electricity during assembly and maintenance of this kind of duct unit, it is necessary to remove any electrical charges that may have accumulated during assembly and to prevent the fan from being affected by static electricity. be.

In Patent Document 1, when a charged worker is about to touch an electrode carelessly, the worker approaches a metal support plate first, and discharges electricity to the support plate to eliminate the charge on the worker. to avoid affecting the electrical parts connected to it.

Japanese Patent Application Publication No. 2011-175204

The configuration of Patent Document 1 is effective when the worker itself is electrically charged, but if the duct part of the fan duct using an insulating material is electrically charged, static electricity will not escape even if the fan duct is placed close to the support plate. Therefore, the charged electricity is not removed. Further, when the duct section is charged, the fan itself is also charged due to inductive charging, so there is a risk that discharge may occur when connecting the connector of the fan, easily leading to electrostatic damage.

Therefore, an object of the present invention is to suppress charging during assembly and maintenance of a duct unit having a fan.

An image forming apparatus according to an embodiment of the present invention is an image forming apparatus that forms an image on a recording material, and includes a support frame, a fan, and a duct that guides air taken in by the fan. and a duct unit attached to the support frame, the support frame has a facing part that faces the duct when the duct unit is attached, and the duct unit has a , further comprising a rib extending in a direction in which the duct unit is attached to the support frame and protruding from an outer surface of the duct.

It is possible to suppress charging during assembly and maintenance of a duct unit having a fan.

Schematic diagram of image forming device External perspective view of the entire casing of the image forming apparatus External perspective view of the vicinity of the duct unit (a) External perspective view of the right side of the duct unit (b) External perspective view of the left side of the duct unit Cross section of duct unit Right side external view of duct unit Left side external view of duct unit Top view of duct unit Perspective view showing how to assemble the duct unit Diagram showing the charging effect of a fan A perspective view showing how to assemble the duct unit of the second embodiment

<First embodiment>
Embodiments of the present invention will be described below based on the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the following embodiments should be changed as appropriate depending on the configuration of the device to which the present invention is applied and various conditions. It is not intended to limit the scope of the present invention to only those examples.

[Image forming system]
FIG. 1 is a schematic diagram showing an image forming system 100S according to this embodiment. The image forming system 100S includes an image forming apparatus 100 and a finisher 600. The image forming apparatus 100 is the image forming apparatus of this embodiment, and the finisher 600 is the sheet processing apparatus of this embodiment.

A housing 101 of the image forming apparatus includes a first housing 101a and a second housing 101b, and the first housing 101a is provided with an image forming section 102, an intermediate transfer belt 106 described later, a storage 113, etc. .

On the other hand, the second housing 101b is provided with a first fixing device 150, a second fixing device 160, a reversing conveyance path 135, etc., which will be described later.

The image forming section 102 includes image forming units 120, 121, 122, and 123 that form toner images of yellow, magenta, cyan, and black, and an intermediate transfer belt 106. In each of the image forming units 120 to 123, a primary charger 111 charges the surface of a photosensitive drum 105, which is a drum-shaped photosensitive member. The laser scanner unit 107 performs exposure processing on the photosensitive drum 105 based on a command signal generated based on image data and transmitted to the laser scanner unit 107 . The laser scanner unit 107 has a laser driver that turns on and off the laser light emitted from a semiconductor laser (not shown), and distributes the laser light from the semiconductor laser in the main scanning direction using a rotating polygon mirror while passing through the reflecting mirror 109. The photosensitive drum 105 is guided through the photosensitive drum 105. As a result, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 105.

The developing device 112 accommodates a developer containing toner therein, and supplies charged toner particles to the photosensitive drum 105 . By adhering toner particles to the drum surface according to the surface potential distribution, the electrostatic latent image carried on the photosensitive drum 105 is visualized as a toner image. The toner image carried on the photosensitive drum 105 is transferred (primary transfer) to an intermediate transfer belt 106 to which a voltage having a polarity opposite to the normal charging polarity of the toner is applied. When forming a color image, the toner images formed by the four image forming units 120 to 123 are multiple-transferred onto the intermediate transfer belt 106 so as to overlap each other, thereby forming a full-color toner image on the belt. Ru.

On the other hand, the feeding processing mechanism feeds the recording materials 1 one by one toward the transfer roller 114 from the storage 113 inserted into the housing 101 of the image forming apparatus 100 so as to be able to be pulled out. The toner image carried on the intermediate transfer belt 106, which is an intermediate transfer member, is transferred (secondary transfer) onto the recording material 1 by the transfer roller 114.

Around the intermediate transfer belt 106, there are an image formation start position detection sensor 115 for determining the print start position when forming an image, a feed timing sensor 116 for determining the feeding timing of the recording material 1, and a density sensor. 117 are arranged. Density sensor 117 measures the density of the patch image carried on intermediate transfer belt 106 . The printer controller adjusts the operating conditions of the image forming unit 102 (for example, the setting of the charging target potential of the primary charger 111 and the bias voltage of the developing device 112) based on the detection result of the density sensor 117.

The fixing processing mechanism of this embodiment includes a first fixing device 150 and a second fixing device 160. The first fixing device 150 includes a fixing roller 151 for applying heat to the recording material 1, a pressure belt 152 for pressing the recording material 1 against the fixing roller 151, and detects completion of the fixing process by the first fixing device 150. A first post-fixing sensor 153 is included. Each roller including the fixing roller 151 is a hollow roller, and each roller has a heater inside. The first fixing device 150 applies heat and pressure to the toner image on the sheet while conveying the recording material 1 while sandwiching it between a fixing roller 151 and a pressure belt 152, which are a pair of rotating bodies. As a result, the toner particles are melted and then fixed, thereby fixing the image on the recording material 1.

The second fixing device 160 is arranged downstream of the first fixing device 150 in the conveyance path of the recording material 1 . The second fixing device 160 has a function of increasing the gloss of the image that has been fixed by the first fixing device 150 and ensuring the fixability of the image to the recording material 1. Like the first fixing device 150, the second fixing device 160 includes a fixing roller 161 and a pressure roller 162 as a pair of rotating bodies that heat and pressurize the recording material 1 while conveying it, and a fixing roller 162 that performs the fixing process by the second fixing device 160. It has a second post-fixing sensor 163 that detects completion.

Note that depending on the type of recording material 1, it may not be necessary to pass it through the second fixing device 160. In such a case, the image forming apparatus 100 includes a detour conveyance path 130 for discharging the recording material 1 without passing through the second fixing device 160 in order to reduce energy consumption. The recording material 1 sent out from the first fixing device 150 is guided to either the second fixing device 160 or the detour conveyance path 130 by the first switching flap 131 .

The recording material 1 that has passed through the second fixing device 160 or the detour conveyance path 130 is guided to either the discharge conveyance path 139 or the reverse conveyance path 135 by the second switching flap 132 . The position of the recording material 1 carried into the reversing conveyance path 135 is detected by the reversing sensor 137, and the leading and trailing ends in the sheet conveying direction are swapped by a switchback operation performed by the reversing section 136.

In the case of double-sided printing, the recording material 1 on which an image has been formed on the first side is conveyed again toward the transfer roller 114 via the re-conveying path 138 with its leading and trailing edges switched by the reversing section 136, and then transferred to the transfer roller 114 again. Images are formed on two sides. The recording material 1 on which image formation has been completed in single-sided printing or the recording material 1 on which image formation has been completed on the second side in double-sided printing is delivered to the image forming apparatus 100 by an ejection roller 139a (ejection section) provided in an ejection conveyance path 139. It is discharged to the outside. Note that a switching flap 134 is provided between the reversing conveyance path 135 and the ejection conveyance path 139, which can guide the recording material 1 switched back by the reversing section 136 toward the ejection conveyance path 139, so that the recording material 1 can be ejected from the image forming apparatus. It is configured such that the front and back sides of the recording material 1 can be selected when printing. Note that an image reading device 200 that reads image information from a document is installed above the image forming apparatus 100. The sheet discharged by the discharge roller 139a is sent to the finisher 600, and is stacked on a tray of the finisher 600 as a product.

[Airflow configuration]
FIG. 2 is an external view of the first housing 101a of the image forming apparatus of the present invention. As shown in FIG. 2, on the front of the first housing 101a, there are a left front door 170a and a right front door 170b, which serve as exterior covers that constitute part of the exterior of the image forming apparatus 100, at approximately the center in the left-right direction as shown in the figure. It is set up so that it can be opened and closed with double doors. A cover duct 171 having an air intake port 171a on a part of the lower surface is provided above the left front door 170a. FIG. 3 shows an external perspective view of the duct unit. (a) shows a perspective view of the right side of the duct unit, and (b) shows a perspective view of the left side of the duct unit.

As shown in FIG. 3A, the cover duct 171 has three intake ports 171a and a filter 172 provided at each intake port. The cover duct 171 is connected to a duct unit 174 shown in FIG. Further, the duct unit 174 is fixed to a support frame 190 of the housing 101a. Here, the support frame 190 is a frame that supports units in the housing 101a, such as the image forming units 120 to 123 described above. The support frame 190 includes a bottom plate (not shown), a plurality of columns such as a left front column 190d and a left rear column 190e that are erected from the bottom plate, and a main body front upper beam 190a and a main body upper left beam 190b supported by the columns, respectively. It is composed of stays etc. that connect the pillars.

The duct unit 174 is fixed to a cover support member 190c connected to the front upper beam 190a of the support frame 190 and the upper left beam 190b of the support frame 190. In this embodiment, the duct unit 174 is directly fixed to the support frame 190 at the front upper beam 190a of the main body, and indirectly fixed to the upper left beam 190b of the main body via the cover support member 190c. There is.

Duct unit 174 has fans 180a-f. The fans 180a to 180f are connected to the duct unit 174 so that their intake ports are attached. The fans 180a to 180f are, for example, sirocco fans, and the fans 180a, 180b, and 180c are provided on one side of the duct unit 174, and the fans 180d, 180e, and 180f are mounted on the opposite side so as to face each other. Note that in this embodiment, the duct portion of the duct unit 174 is formed of a resin member.

When arranging a plurality of fans 180, in order to prevent the opposing fans 180 from receiving the influence of intake air, the arrangement of the fans was studied using airflow simulation. As shown in FIG. 4, in this embodiment, the fans 180a to 180f, which are located at opposite positions via the internal duct unit 174, are arranged at positions that do not overlap with each other in the intake direction (the rotational axis direction of the fans). Suppresses drifting current. Note that a configuration may be adopted in which four fans 180a to 180d are arranged on one side and two fans 180e and 180f are arranged on the opposite side.

In general, it is possible to prevent uneven flow by not arranging obstacles such as walls within 20 mm from the fan's intake port. Therefore, the width of the duct unit 174 in the X-axis direction is Considering the influence of intake air, the length is set to 40 mm.

In the duct unit 174, the air taken in by the fans 180a to 180c is guided further downstream by the duct part 174b, and the air taken in by the fans 180d to f is guided further downstream by the duct part 174a.

Further, the exhaust ports of the duct portions 174a and 174b are connected to a joint duct 175 extending toward the front side (+Y side) of the main body. Further, as shown in FIGS. 5 and 6, air flow inside the duct portions 174a, 174b and the joint duct 175 is partitioned for each of the fans 180a to 180f.

The joint duct 175 is supported by the duct unit 174 and the front upper beam 190a of the main body. In the air flow of the joint duct 175, the upstream side is connected to the duct unit 174, and the downstream side is connected to the inner cover duct 173 (FIG. 7) for each path of the fans 180a to 180f. As shown in FIG. 7, the opening of the inner cover duct 173 on the opposite side from the joint duct 175 is connected to each image forming unit 120, 121, 123, and 124.

Air taken into the duct unit 174 through the intake port 171a passes through the inner cover duct 173 and is blown to the charger 111 and the developer 112 of the image forming units 120 to 123. In this embodiment, the airflow blown to the charger 111 functions as an airflow for recovering ozone generated by corona discharge. Further, in this embodiment, the air flow blown to the developing device 112 functions as an air flow for cooling the developing device 112 itself.

[Detailed configuration of unit]
When assembling the product or performing maintenance, the duct unit 174 is assembled to the support frame 190 from the top of the casing 101a in the -Z direction (vertical direction), as shown in FIG. As described above, the duct unit 174 has the fans 180a to 180f, and is heavier than a duct unit having only one fan. Therefore, in this embodiment, when assembling the duct unit 174 to the support frame 190, the duct unit 174 is assembled along the upper left beam 190b of the main body of the support frame 190 in consideration of the load on the operator. In this embodiment, the main body upper left beam 190b is an example of a facing portion that faces the duct portion 174a when the duct unit 174 is mounted on the support frame 190.

In this case, there is a possibility that the duct portion 174a of the duct unit 174 may become electrically charged due to rubbing against the upper left beam 190b of the main body. When the duct part 174a is charged due to rubbing in this way, the fans 180e to 180f fixed to the duct part 174a are also charged due to inductive charging, so discharge occurs when the fan connector is connected, leading to electrostatic damage. There was a fear that it would become easier.

Therefore, in this embodiment, ribs 181a, 181b having a width of 2.5 mm and a height of 0.6 mm extending in the +Z direction are provided on the duct portion 170a provided on the side surface on the +X side opposite to the upper left beam 190b of the main body of the duct unit 174. 181c was established. That is, the duct portion 174a is provided with ribs 181a, 181b, and 181c extending in the direction in which the duct unit 174 is attached to the support frame 190 and protruding from the outer surface of the duct portion 170a.

These ribs 181a to 181c are provided to reduce the area where the duct portion 174a rubs against the front upper beam 190a of the main body when the duct unit 174 is assembled to the support frame 190. This suppresses charging of the duct portion 174a of the duct unit 174 when the duct unit 174 is assembled to the support frame 190, and suppresses charging of the fans 180d to 180f due to the charging of the duct portion 174a. ing.

FIG. 9 is a graph comparing the amount of charge when the ribs 181a to 181c are provided on the duct portion 174a as in this embodiment, and the amount of charge when the ribs 181a to 181c are not provided. In FIG. 9, the values shown by broken lines are the amount of charge on fans 180d to f when ribs 181a to 181c are not provided, and the values shown by solid lines are the amount of charge on fans 180d to f when ribs 181a to 181c are provided. be.

As shown in FIG. 9, in the duct unit 174 having the ribs 181a to 181c shown in the embodiment described above, the amount of charge generated by the fans 180e to 180f when the duct unit is assembled is 2 times higher than that in the case where no ribs are provided. It has been confirmed that the

In this embodiment, no rib is provided for the duct portion 174b that is not moved along a part of the support frame 190 during assembly. However, if a member that is likely to rub, such as a part of the support frame 190, is located at a position facing the duct portion 174b, a rib may also be provided on the duct portion 174b.

<Second embodiment>
Next, a duct unit 274 that is different from the first embodiment described above will be explained. The duct unit 274 differs from the first embodiment described above only in the attachment direction to the support frame 190 and the position of the ribs. Therefore, the support frame 190 will be given the same reference numeral and its description will be omitted.

The duct unit 274 in this embodiment can be assembled in the -Y direction (horizontal direction) to the support frame 190 of the housing 101a, as shown in FIG. The duct unit 274 has six fans as in the first embodiment, so it is heavier than the duct unit with only one fan. Therefore, in consideration of the load on the worker, in this embodiment, it is assumed that the support frame 190 is assembled along the left front column 190d. In this embodiment, the left front column 190d is an example of a facing portion that faces the duct portion 274a when the duct unit 274 is attached to the support frame 190.

Therefore, in this embodiment, ribs 281da, 281b, and 281c, each having a width of 2.5 mm and a height of 0.6 mm and extending in the +Y direction, are provided at three locations on the duct portion 274a provided on the +X side surface of the duct unit 274. It is being That is, the duct portion 274a is provided with ribs 281da, 281b, and 281c extending in the direction in which the duct unit 274 is attached to the support frame 190 and protruding from the outer surface of the duct portion 270a.

This reduces the area where the ribs 281a to 281c rub against the left front column 190d when the duct unit 274 is assembled to the support frame 190. Also in this configuration, as in the first embodiment shown in FIG. 9, the amount of charge generated on the fans 280e to 280f when the duct unit 274 is assembled is 20% or less compared to the case where the ribs 281a to 281c are not provided. This was confirmed. Therefore, in this embodiment as well, when the duct unit 274 is assembled to the support frame 190, the duct portion 274a of the duct unit 274 is suppressed from being charged, and the fans 280d to 180f due to the duct portion 274a being charged are suppressed. electrification could be suppressed.

<Other embodiments>
In the embodiment described above, a configuration is shown in which a total of three ribs 181a to 181c are provided on the duct portion 174a of the duct unit 174, but the configuration is not limited to this. For example, a configuration may be adopted in which two or less ribs or four or more ribs are provided. Even with this configuration, charging due to rubbing of the duct portion when the duct unit is attached can be suppressed compared to a configuration in which the duct portion is not provided with ribs.

100 Image forming apparatus 101a First housing 105 Photosensitive drum 111 Charger 112 Developing device 120 (121-123) Image forming unit 190 Support frame 174 Duct unit 174a Duct part 180a-f Fan 181a-c Rib

Claims (5)

An image forming apparatus that forms an image on a recording material,
a support frame;
a duct unit that has a fan and a duct that guides air taken in by the fan, and is attached to the support frame;
The support frame has a facing portion that faces the duct when the duct unit is installed,
The duct unit has a rib extending in a direction in which the duct unit is attached to the support frame and protruding from an outer surface of the duct.
An image forming apparatus characterized by: The mounting direction of the duct unit is a vertical direction.
The image forming apparatus according to claim 1, characterized in that: The mounting direction of the duct unit is a horizontal direction.
The image forming apparatus according to claim 1, characterized in that: The duct unit includes, in the rotation axis direction of the fan, another fan provided on a side surface opposite to the side surface where the fan and the duct are provided, and the other fan provided on the opposite side surface. and another duct for guiding the intake air,
The image forming apparatus according to any one of claims 1 to 3, characterized in that: The image forming unit further includes a photoconductor, a charger that charges the photoconductor by corona discharge, and a developer that develops the electrostatic latent image formed on the photoconductor using toner,
the duct unit blows air taken in by the fan to the image forming unit;
The image forming apparatus according to any one of claims 1 to 4.

Images