JP2020160140A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can effectively protect a low temperature part from a high-temperature ascending air current generated from a high temperature part without using electric power.SOLUTION: An image forming apparatus 1 comprises: a high temperature part that includes a heat source; and a low temperature part that is arranged above and shifted in the horizontal direction from the high temperature part and has a lower temperature than the high temperature part. The image forming apparatus includes an air current control unit 40 that is arranged between the high temperature part and the low temperature part, and above and shifted in the horizontal direction toward the low temperature part from the high temperature part, and has a plurality of blades 42 inclined in a direction ascending from the low temperature part toward the high temperature part in the horizontal direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image forming apparatus.

In image forming devices such as copiers and printers, a heat fixing method is widely adopted in order to fix an unfixed toner image transferred to a recording medium such as paper to a recording medium. The fixing portion for fixing the unfixed toner image on the recording medium by heating and pressurizing is a high temperature portion including a heat source. Then, the low temperature portion, which is arranged above the fixing portion which is the high temperature portion and whose temperature is lower than the high temperature portion, is exposed to the high temperature updraft generated from the high temperature portion, and the temperature may rise unintentionally. is there. Patent Document 1 discloses an example of an image forming apparatus proposed to solve a problem caused by such a high temperature updraft.

The conventional image forming apparatus disclosed in Patent Document 1 includes a side frame arranged on the outside of the image forming portion, a substrate on which heat-generating electric components arranged on the lower outside of the side frame are mounted, and a side frame. It is provided with a duct mounted on the outer upper part of the board and covering the upper space of the substrate, and an exhaust device for discharging the air in the duct to the outside. As a result, the heat generated from the substrate is discharged to the outside without entering the inside of the side frame. Therefore, it is possible to prevent the updraft formed by the heat generated by the substrate from adversely affecting the precision equipment in the image reading unit provided in the upper part of the image forming apparatus.

Japanese Unexamined Patent Publication No. 2009-244672

However, the conventional image forming apparatus disclosed in Patent Document 1 requires a power source for driving an exhaust fan, which is an exhaust device, and the exhaust device does not function when the power supply is OFF. For example, when the power is turned off after using the image forming apparatus, the exhaust apparatus is stopped, so that there is a concern that the residual heat of the substrate may not be discharged to the outside and the image reading unit may be adversely affected. To.

The present invention has been made in view of the above points, and an image forming apparatus capable of effectively protecting a low temperature portion against a high temperature updraft generated from a high temperature portion without using a power source. The purpose is to provide.

In order to solve the above problems, the present invention provides an image forming apparatus including a high temperature portion including a heat source and a low temperature portion having a temperature lower than that of a high temperature portion arranged above the high temperature portion and horizontally displaced. In the above, above the high temperature part and horizontally shifted to the low temperature part side, and inclined in the upward direction from the low temperature part side to the high temperature part side in the horizontal direction. It is provided with an airflow control unit having a plurality of blades.

According to the configuration of the present invention, the high-temperature updraft generated from the high-temperature portion is circulated in the direction away from the low-temperature portion by the plurality of blade plates. This makes it possible to effectively protect the low temperature portion against the high temperature updraft without using a power source. Further, the low-temperature air can be carried to the periphery of the low-temperature portion by being pulled by the high-temperature updraft, and a low-temperature air layer can be formed around the low-temperature portion. Therefore, it is possible to protect the low temperature portion even more effectively.

It is schematic cross-sectional view which shows the structure of the image forming apparatus of embodiment of this invention. It is a partial cross-sectional view which shows the periphery of the airflow control part of the image forming apparatus of an embodiment of this invention. It is a perspective view of the airflow control part of the image forming apparatus of an embodiment of this invention. It is explanatory drawing which shows the air flow direction and the air flow temperature around the exposed part and the fixing part of the Example of the image forming apparatus of embodiment of this invention. It is explanatory drawing which shows the airflow direction and the airflow temperature around the exposed part and the fixing part of the comparative example with respect to the image forming apparatus of embodiment of this invention. It is a perspective view of the airflow control part of the image formation apparatus of the modification 1 of the embodiment of this invention. It is a perspective view of the airflow control part of the image formation apparatus of the modification 2 of the Embodiment of this invention. It is sectional drawing of the airflow control part of the image formation apparatus of the modification 3 of the Embodiment of this invention. It is the schematic sectional drawing at the time of power-on of the image forming apparatus of the modification 4 of the embodiment of this invention. It is the schematic sectional drawing at the time of power-off of the image forming apparatus of the modification 4 of the embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following contents.

FIG. 1 is a schematic cross-sectional view showing the configuration of the image forming apparatus 1 of the embodiment. An example of the image forming apparatus 1 of the present embodiment is a so-called printer that receives image data related to a printing job and a printing command from an external computer and executes printing.

As shown in FIG. 1, the image forming apparatus 1 includes a paper feeding unit 2, a paper conveying unit 3, an exposure unit 4, an image forming unit 20, a transfer unit 5, a fixing unit 30, a paper ejection unit 7, and an operation unit 8. ..

The paper feeding unit 2 accommodates a plurality of sheets of recording media P, and separates and sends out the paper P one by one at the time of printing. The paper transport unit 3 transports the paper P fed from the paper feed unit 2 to the transfer unit 5 and the fixing unit 30, and further discharges the fixed paper P from the paper ejection port 3a to the paper ejection unit 7. The exposure unit 4 irradiates the image forming unit 20 with a laser beam controlled based on the image data.

The image forming unit 20 includes a photoconductor drum 21. The photoconductor drum 21 is an image carrier having a photosensitive layer formed on its surface and rotatably supported in a predetermined direction (clockwise in FIG. 1). The image forming unit 20 further includes a charging unit 22, a developing unit 23, and a cleaning unit 24 around the photoconductor drum 21 along the direction of rotation thereof. The transfer unit 5 is arranged between the developing unit 23 and the cleaning unit 24.

The charging unit 22 charges the surface of the photoconductor drum 21 to a predetermined potential by, for example, corona discharge. The exposure unit 4 forms an electrostatic latent image by exposing the photoconductor drum 21 charged by the charging unit 22. The developing unit 23 attaches toner to the electrostatic latent image formed on the surface of the photoconductor drum 21 to form a toner image.

The transfer unit 5 is arranged below the image forming unit 20. The transfer unit 5 is arranged on the upstream side of the paper transport unit 3 in the paper transport direction with respect to the fixing portion 30. The transfer unit 5 transfers the toner image on the surface of the photoconductor drum 21 formed by the developing unit 23 to the paper P. The cleaning unit 24 cleans by removing toner and the like remaining on the surface of the photoconductor drum 21 after transfer.

The fixing unit 30 heats and pressurizes the paper P on which the toner image is transferred, and fixes the toner image transferred to the paper P by the transfer unit 5.

The operation unit 8 is arranged on the front side of the upper part of the image forming apparatus 1. The operation unit 8 accepts operations such as setting input related to printing by the user, for example. Further, the operation unit 8 has a display unit (not shown) composed of, for example, a liquid crystal panel. The operation unit 8 displays, for example, information, precautions, error messages, and the like related to the operating state of the image forming apparatus 1 on the display unit.

Further, the image forming apparatus 1 includes a control unit (not shown). The control unit includes a CPU (not shown), an image processing unit, a storage unit, other electronic circuits, and electronic components (not shown). The CPU controls the operation of each component provided in the image forming apparatus 1 based on the control program or data stored in the storage unit, and performs processing related to the function of the image forming apparatus 1. Each of the paper feed unit 2, the paper transport unit 3, the exposure unit 4, the image forming unit 20, the transfer unit 5, and the fixing unit 30 receives commands individually from the control unit and interlocks to print on the paper P. The storage unit is composed of a combination of a non-volatile storage device such as a program ROM (Read Only Memory) and a data ROM (not shown) and a volatile storage device such as a RAM (Random Access Memory).

Further, the image forming apparatus 1 includes an airflow control unit 40. The airflow control unit 40 is arranged between the fixing unit 30 and the exposure unit 4.

Subsequently, the configuration of the airflow control unit 40 and its surroundings will be described with reference to FIGS. 1, 2 and 3. FIG. 2 is a partial cross-sectional view showing the periphery of the airflow control unit 40 of the image forming apparatus 1. FIG. 3 is a perspective view of the airflow control unit 40.

As shown in FIG. 1, the fixing portion 30 is arranged in a lateral direction substantially horizontal to the image forming portion 20. As shown in FIG. 2, the fixing portion 30 includes a fixing roller 31, a pressure roller 32, and a heat source 33.

The fixing roller 31 and the pressure roller 32 are each formed in a cylindrical shape, and are arranged so that their peripheral surfaces face each other with the paper transport portion 3 sandwiched from above and below. The rotation axes of the fixing roller 31 and the pressure roller 32 extend along the paper width direction (paper surface depth direction in FIG. 2). The fixing roller 31 and the pressure roller 32 have a length over the entire area of the paper transport section 3 in the paper width direction.

The fixing roller 31 and the pressure roller 32 are rotatably supported by the housing portion of the fixing portion 30. The fixing roller 31 receives power from a motor (not shown) and rotates clockwise in FIG. The pressurizing roller 32 receives power from a motor (not shown) and rotates counterclockwise in FIG.

A predetermined pressure is applied to the pressure roller 32 toward the fixing roller 31 side by a pressure mechanism using a pressure spring or the like (not shown). As a result, the peripheral surface of the pressure roller 32 presses against the peripheral surface of the fixing roller 31 to come into contact with each other to form a fixing nip portion.

The heat source 33 is arranged inside the fixing roller 31. The heat source 33 is composed of, for example, a halogen lamp or a resistance heating element, and has a rod shape extending in parallel with the fixing roller 31 in the paper width direction. The heat source 33 heats the fixing roller 31 from the inside of the fixing roller 31. As a result, the heat generating layer on the peripheral surface of the fixing roller 31 generates heat, and when the paper P on which the unfixed toner image is transferred passes through the fixing nip portion, the paper P is heated and the toner is fixed to the paper P. ..

As described above, the fixing portion 30 is a high temperature portion including the heat source 33.

As shown in FIG. 1, the exposed unit 4 is arranged above the image forming unit 20. The exposure unit 4 is composed of, for example, an LSU (Laser Scanner Unit), and irradiates a laser beam toward the surface of the photoconductor drum 21.

The exposed portion 4 is a low temperature portion having a lower temperature than the fixing portion 30 which is a high temperature portion. That is, the image forming apparatus 1 has a fixing portion 30 which is a high temperature portion including a heat source 33 and an exposure portion which is a low temperature portion whose temperature is lower than that of the fixing portion 30 which is arranged above the fixing portion 30 and displaced in the horizontal direction. 4 and.

The airflow control unit 40 is arranged between the fixing unit 30 which is a high temperature unit and the exposure unit 4 which is a low temperature unit. The airflow control unit 40 is arranged above the fixing unit 30 and horizontally offset to the exposure unit 4. As shown in FIG. 3, the airflow control unit 40 includes a side wall portion 41 and a plurality of wing plates 42.

The side wall portions 41 are arranged at both ends of the airflow control portion 40 in the paper width direction. The side wall portion 41 is formed of, for example, a plate shape extending in the vertical direction and the paper transport direction. The two side wall portions 41 are arranged so as to face each other in the paper width direction. A plurality of wing plates 42 are fixed to the side wall portion 41, and the plurality of wing plates 42 are supported. The side wall portion 41 may be formed of a main body frame portion or the like of the image forming apparatus 1.

The plurality of wing plates 42 are arranged and fixed between two side wall portions 41 facing each other in the paper width direction. In the present embodiment, the airflow control unit 40 has three blade plates 42, but the number of blade plates 42 can be arbitrarily changed. The plurality of wing plates 42 are arranged side by side in the vertical direction and extend in the paper width direction in parallel with each other. The plurality of wing plates 42 are inclined in the upward direction as they approach from the exposed portion 4 side, which is a low temperature portion, to the fixing portion 30 side, which is a high temperature portion, in the horizontal direction.

Subsequently, the airflow direction and the airflow temperature around the exposed portion and the fixing portion of the image forming apparatus 1 of the embodiment including the airflow control unit 40 and the image forming apparatus of the comparative example not provided with the airflow control unit will be described. FIG. 4 is an explanatory diagram showing the airflow direction and the airflow temperature around the exposed portion 4 and the fixing portion 30 of the embodiment of the image forming apparatus 1 of the embodiment of the present invention. FIG. 5 is an explanatory diagram showing the airflow direction and the airflow temperature around the exposed portion 104 and the fixing portion 130 of the comparative example with respect to the image forming apparatus 1 of the embodiment of the present invention.

A fluid simulation was carried out for each of the image forming apparatus 1 of the example and the image forming apparatus of the comparative example, and the airflow direction and the airflow temperature around the exposed portion and the fixing portion were calculated. The calculation results are shown in FIGS. 4 and 5. The arrows in FIGS. 4 and 5 indicate the direction of the airflow, and the arrows indicate that the airflow temperature changes from low temperature to high temperature in the order of a dotted line, a broken line, and a solid line.

According to FIG. 5, in the image forming apparatus of the comparative example, it can be seen that a high-temperature updraft is generated from the fixing portion 130. Then, in the case of the image forming apparatus of the comparative example, it can be seen that the high-temperature updraft generated from the fixing portion 130 hits the vicinity of the end portion of the exposure portion 104 on the fixing portion 130 side.

According to FIG. 4, in the image forming apparatus 1 of the embodiment, it can be seen that a high-temperature updraft is generated from the fixing portion 30. Then, in the case of the image forming apparatus 1 of the embodiment, the high-temperature updraft generated from the fixing portion 30 is circulated by the plurality of blade plates 42 in the direction away from the exposed portion 4 (to the left in FIG. 4). I understand. This makes it possible to effectively protect the exposed unit 4 against a high-temperature updraft without using a power source. Further, the low-temperature air can be carried to the periphery of the exposed portion 4 in the form of being pulled by the high-temperature updraft, and a low-temperature air layer can be formed around the exposed portion 4. Therefore, it is possible to protect the exposed portion 4 even more effectively.

If there are a plurality of wing plates 42, air easily flows between the wing plates 42 to generate an air flow. However, when there is only one wing plate 42, airflow is unlikely to occur. Further, when there is only one wing plate 42, the wing plate 42 itself is warmed by the high temperature air from the fixing portion 30, and heat is transferred to the exposed portion 4 side. Therefore, it is preferable that the number of wing plates 42 is plurality.

Further, when the inclination angle of the blade plate 42 with respect to the horizontal direction is relatively small, a high-temperature updraft from the fixing portion 30 is less likely to occur. On the other hand, when the tilt angle of the blade plate 42 with respect to the horizontal direction is relatively large, the high-temperature updraft from the fixing portion 30 tends to approach the exposed portion 4. Therefore, the inclination angle of the wing plate 42 with respect to the horizontal direction is preferably about 45 degrees.

As shown in FIG. 2, the upper end portion of each of the plurality of blade plates 42 inclined up and down with respect to the horizontal direction is located above the fixing portion 30. That is, the upper end portion of the wing plate 42 overlaps with the fixing portion 30 which is a high temperature portion when viewed from the vertical direction. According to this configuration, the high-temperature updraft generated from the fixing portion 30 can be easily kept away from the exposed portion 4. Therefore, it is possible to improve the action of protecting the exposed portion 4 against a high-temperature updraft.

Next, the image forming apparatus of the first modification of the embodiment will be described. FIG. 6 is a perspective view of the airflow control unit 40 of the image forming apparatus of the first modification. Since the basic configuration of this modification 1 is the same as that of the embodiment (see FIG. 1) described above, the common components are given the same reference numerals or the same names as before to be described. It may be omitted, and the description of the configuration other than the featured parts is omitted.

As shown in FIG. 6, the airflow control unit 40 of the image forming apparatus of the first modification includes a side wall portion 41, a plurality of blade plates 42, and a rectifying plate 43.

The straightening vane 43 is arranged above the airflow control unit 40 in the first modification of the present embodiment. The straightening vane 43 is arranged between two side wall portions 41 facing each other in the paper width direction. The straightening vane 43 extends upward from the upper end portion of the blade plate 42 arranged at the uppermost portion of the plurality of blade plates 42. The straightening vane 43 is composed of, for example, a plate shape extending in the vertical direction and the paper width direction.

According to the configuration of the first modification, it is possible to prevent the high-temperature updraft flowing on the fixing portion 30 side of the airflow control unit 40 from wrapping around to the exposed portion 4 side. Therefore, it is possible to improve the action of protecting the exposed portion 4 against a high-temperature updraft. Further, according to the above configuration, the strength of the airflow control unit 40 can be increased.

The straightening vane may be configured to extend downward from the lower end of the blades 42 arranged at the lowermost portion of the plurality of blades 42.

Next, the image forming apparatus of the second modification of the embodiment will be described. FIG. 7 is a perspective view of the airflow control unit 40 of the image forming apparatus of the second modification. Since the basic configuration of this modification 2 is the same as that of the embodiment (see FIG. 1) described above, the common components are given the same reference numerals or the same names as before to be described. It may be omitted, and the description of the configuration other than the featured parts is omitted.

As shown in FIG. 7, the airflow control unit 40 of the image forming apparatus of the second modification includes a side wall portion 41, a plurality of wing plates 42, and a rib portion 44.

The rib portion 44 is arranged on the upper surface of the wing plate 42 in the second modification of the present embodiment. The rib portion 44 extends upward from the upper surface of the wing plate 42. The rib portion 44 is arranged on all three wing plates 42 in the second modification of the present embodiment, but it may be arranged on any one or two wing plates 42. Further, in the second modification of the present embodiment, three rib portions 44 are arranged on each of the three blade plates 42, but the number of rib portions 44 can be arbitrarily changed.

Further, although the rib portion 44 has a configuration extending upward from the upper surface of the wing plate 42 in the second modification of the present embodiment, the rib portion 44 may have a configuration extending downward from the lower surface of the wing plate 42. Further, the rib portion 44 may be arranged on both the upper surface and the lower surface of the wing plate 42, and each may extend in the vertical direction. Further, the rib portion 44 may be arranged between the wing plates 42 facing in the vertical direction, and may have a shape that connects the upper wing plate 42 and the lower wing plate 42 in the vertical direction.

As described above, in the airflow control unit 40 of the image forming apparatus of the modification 2, at least one of the blade plates 42 includes a rib portion 44 extending from the surface toward at least one of the upper side and the lower side. According to this configuration, the rectifying action of the air flow flowing through the airflow control unit 40 can be improved. As a result, the high-temperature ascending airflow generated from the fixing unit 30 can be efficiently circulated in the direction away from the exposed unit 4 by the airflow control unit 40. Therefore, it is possible to protect the exposed portion 4 more effectively against the high temperature updraft.

Next, the image forming apparatus of the third modification of the embodiment will be described. FIG. 8 is a cross-sectional view of the airflow control unit 40 of the image forming apparatus of the modification example 3. Since the basic configuration of this modification 3 is the same as that of the embodiment (see FIG. 1) described above, the common components are given the same reference numerals or the same names as before and the description thereof will be described. It may be omitted, and the description of the configuration other than the featured parts is omitted.

As shown in FIG. 8, the airflow control unit 40 of the image forming apparatus of the modification 3 includes a side wall portion 41 and a plurality of blade plates 45.

The plurality of wing plates 45 are arranged between two side wall portions 41 facing each other in the paper width direction, and are rotatably supported by the two side wall portions 41. Each of the plurality of wing plates 45 is rotatably supported by the side wall portion 41 about the axis extending in the paper width direction of the shaft portion 45a extending in the paper width direction.

The airflow control unit 40 further includes a blade plate drive unit 50. The wing plate drive unit 50 includes a wing plate gear 51, a rack 52, a drive gear 53, and a motor 54.

The wing plate gear 51 is fixed to the shaft portion 45a of the wing plate 45. The blade plate gear 51 rotates about the axis that coincides with the shaft portion 45a and extends in the paper width direction. The wing plate gear 51 is individually fixed to each of the shaft portions 45a of the three wing plates 45.

The rack 52 is arranged, for example, on the upstream side (right side in FIG. 8) of the blade gear 51 in the paper transport direction. The rack 52 is formed in the shape of a flat plate rod, for example, and extends in the vertical direction. The rack 52 is slidably supported in the vertical direction by a guide portion (not shown).

The rack 52 has teeth of the same shape engraved at equal intervals on one surface extending in the vertical direction on the downstream side in the paper transport direction (left side in FIG. 8) and one surface extending in the vertical direction on the upstream side in the paper transport direction. ing. The teeth on the downstream side of the rack 52 in the paper transport direction mesh with the teeth of the wing plate gear 51. The teeth on the upstream side of the rack 52 in the paper transport direction mesh with the teeth of the drive gear 53.

The drive gear 53 is arranged on the upstream side of the rack 52 in the paper transport direction. The drive gear 53 is fixed to the shaft portion 54a of the motor 54. The drive gear 53 rotates about the axis that coincides with the shaft portion 54a and extends in the paper width direction. The rack 52 and the drive gear 53 have a so-called rack and pinion gear configuration.

The drive gear 53 of the motor 54 is fixed to the shaft portion 54a of the motor 54. When the motor 54 rotates the drive gear 53, the rack 52 slides in the vertical direction, and the wing plate gear 51 is rotated. As a result, the three blade plates 45 rotate around the axis of the shaft portion 45a extending in the paper width direction, and the inclination angle changes. By changing the inclination angle of the blade plate 45, the flow direction of air in the airflow control unit 40 can be changed.

The rack 52, the drive gear 53, and the motor 54 may be arranged on the downstream side (left side in FIG. 8) of the wing plate gear 51 in the paper transport direction.

As described above, the airflow control unit 40 of the image forming apparatus of the modification 3 includes the blade plate drive unit 50 capable of changing the inclination angle of the blade plate 45. According to this configuration, for example, the wing plate 45 can be kept in a substantially horizontal state when the image forming apparatus is started. As a result, the generation of an updraft from the fixing portion 30 is suppressed, and high-temperature air tends to stay around the fixing portion 30. Therefore, it is possible to quickly warm the fixing portion 30, and it is possible to accelerate the activation of the image forming apparatus.

When the power of the image forming apparatus is turned off, it is preferable that the plurality of blade plates 45 are tilted in the upward direction as they approach the fixing portion 30 side from the exposure portion 4 side in the horizontal direction. According to this configuration, the high-temperature updraft generated from the fixing portion 30 is circulated in the direction away from the exposed portion 4 by the plurality of blade plates 45. Therefore, it is possible to effectively protect the exposed unit 4 against a high-temperature updraft without using a power source.

Further, the blade plate driving unit 50 may have a configuration different from the above as long as the tilt angle of the blade plate 45 can be changed. For example, a wire, a belt, or the like may be hung on the shaft portion 45a of the wing plate 45 to change the inclination angle of the wing plate 45. Further, the wing plate driving unit 50 may be able to change the inclination angle of only one of the wing plates 45 among the plurality of wing plates 45.

Next, the image forming apparatus of the modified example 4 of the embodiment will be described. FIG. 9 is a schematic cross-sectional view of the image forming apparatus 1 of the modified example 4 when the power is turned on. FIG. 10 is a schematic cross-sectional view of the image forming apparatus 1 of the modified example 4 when the power is turned off. Since the basic configuration of this modification 4 is the same as that of the embodiment (see FIG. 1) described above, the common components are given the same reference numerals or the same names as before and the description thereof will be described. It may be omitted.

The image forming apparatus 1 of the modified example 4 includes a cooling unit 60 as shown in FIGS. 9 and 10. The cooling unit 60 is arranged above the image forming unit 20 and the fixing unit 30 and below the exposed unit 4. The cooling unit 60 includes a ventilation duct 61, an intake port 62, an exhaust port 63, and a blower fan 64.

The ventilation duct 61 extends from, for example, the side wall of the image forming apparatus 1 main body above the developing portion 23 of the image forming portion 20 to the side wall of the image forming apparatus 1 main body on the downstream side in the paper transport direction of the fixing portion 30. The ventilation duct 61 does not intersect with the paper transport unit 3 on the downstream side of the fixing unit 30 in the paper transport direction, and bypasses the paper transport unit 3. One end of the ventilation duct 61 on the upper side of the developing unit 23 is opened as an intake port 62. One end of the ventilation duct 61 on the downstream side of the fixing portion 30 in the paper transport direction is opened as an exhaust port 63.

The blower fan 64 is composed of, for example, an axial fan, and is arranged inside the ventilation duct 61, immediately inside the exhaust port 63. The blower fan 64 sucks the air outside the image forming apparatus 1 from the intake port 62 and guides it to the inside of the ventilation duct 61, and discharges the air inside the ventilation duct 61 from the exhaust port 63 to the outside of the image forming apparatus 1. To do.

In this way, the cooling unit 60 allows air to flow above the photoconductor drum 21, the charging unit 22, the developing unit 23, and the fixing unit 30, and cools the inside of the image forming apparatus 1 including these components.

The airflow control unit 40 of the image forming apparatus 1 of the modification 4 is configured as a part of the ventilation duct 61. The airflow control unit 40 is arranged in the ventilation duct 61 between the fixing unit 30 and the exposure unit 4, and is located above the fixing unit 30 and horizontally displaced toward the exposure unit 4. The airflow control unit 40 includes a blade plate drive unit 50 (see FIG. 8, not shown in FIGS. 9 and 10) capable of changing the inclination angle of the blade plate 45.

The plurality of blade plates 45 are arranged between two side wall portions of the ventilation duct 61 facing each other in the paper width direction, and are rotatably supported by the side wall portions of the ventilation duct 61. Each of the plurality of blade plates 45 is rotatably supported by the side wall portion of the ventilation duct 61 about an axis extending in the paper width direction.

When the power of the image forming apparatus 1 is turned on, as shown in FIG. 9, the plurality of wing plates 45 are held in a substantially horizontal state. That is, each of the plurality of wing plates 45 extends in the paper width direction in a substantially horizontal state. The wing plate 45 arranged at the uppermost portion of the plurality of wing plates 45 is configured as a wall portion of the ceiling of the ventilation duct 61. The wing plate 45 arranged at the bottom of the plurality of wing plates 45 is configured as a bottom wall portion of the ventilation duct 61. As a result, when the power of the image forming apparatus 1 is turned on, the air inside the ventilation duct 61 flows smoothly from the intake port 62 to the exhaust port 63.

When the power of the image forming apparatus 1 is turned off, as shown in FIG. 10, the plurality of blade plates 45 are held in a state of being inclined in the upward direction as they approach from the exposed portion 4 side to the fixing portion 30 side in the horizontal direction. According to this configuration, the high-temperature updraft generated from the fixing portion 30 is circulated in the direction away from the exposed portion 4 by the plurality of blade plates 45. Therefore, it is possible to effectively protect the exposed unit 4 against a high-temperature updraft without using a power source. Further, since the ventilation duct 61 is present above the fixing portion 30, it is possible to prevent the high temperature air from continuing to stay around the fixing portion 30.

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to this, and various modifications can be made without departing from the gist of the invention.

For example, in the above embodiment, the high temperature portion is defined as the fixing portion 30 and the low temperature portion is referred to as the exposure portion 4, but the high temperature portion and the low temperature portion are not limited to these components, and are other components. It's okay.

Further, in the above embodiment, the image forming apparatus 1 is an image forming apparatus for monochrome printing that forms a monochrome image, but the present invention is not limited to such a model, and an image for color printing is used. It may be a forming device.

The present invention can be used in an image forming apparatus.

1 Image forming device 4 Exposed part (low temperature part)
5 Transfer section 20 Image forming section 21 Photoreceptor drum (image carrier)
22 Charging part 23 Developing part 30 Fixing part (high temperature part)
33 Heat source 40 Airflow control unit 41 Side wall part 42, 45 Feather plate 43 Rectifying plate 44 Rib part 50 Feather plate drive part

Claims (6)

In an image forming apparatus including a high temperature portion including a heat source and a low temperature portion having a temperature lower than that of the high temperature portion arranged above the high temperature portion and laterally displaced.
It is located between the high temperature portion and the low temperature portion, above the high temperature portion and horizontally shifted to the low temperature portion side, and rises horizontally from the low temperature portion side to the high temperature portion side. An image forming apparatus including an airflow control unit having a plurality of wing plates inclined in a direction. The image forming apparatus according to claim 1, wherein the upper end portion of the wing plate overlaps with the high temperature portion when viewed from the vertical direction. The image forming apparatus according to claim 1 or 2, further comprising a straightening vane extending upward from the upper end portion of the feather plate arranged at the uppermost portion. The image forming apparatus according to any one of claims 1 to 3, wherein at least one of the wing plates includes a rib portion extending upward or downward from the surface at least one of them. The image forming apparatus according to any one of claims 1 to 4, further comprising a wing plate driving unit capable of changing the inclination angle of the wing plate. An image carrier with a photosensitive layer formed on its surface,
A charged portion that charges the image carrier and
An exposed portion that forms an electrostatic latent image by exposing the image carrier charged by the charged portion, and an exposed portion.
A developing unit that forms a toner image by adhering toner to the electrostatic latent image formed on the image carrier.
A transfer unit that transfers the toner image formed by the developing unit onto a recording medium, and a transfer unit.
A fixing unit for fixing the toner image transferred onto the recording medium by the transfer unit, and a fixing unit.
With
The image forming apparatus according to any one of claims 1 to 5, wherein the high temperature portion is the fixing portion and the low temperature portion is the exposed portion.

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