Image forming apparatus

Abstract

To provide an image forming apparatus that can suppress damage to environmental sensors. [Solution] The image forming apparatus 1 comprises a main body housing 2 that houses an image forming unit 5, a left side cover 23 that constitutes the first surface of the main body housing 2, a first fan 71 and a second fan 72 that exhaust or draw in air to or from the main body housing 2, a vent 23a formed in the left side cover 23 at a position not facing the first fan 71 and the second fan 72, communicating the inside and outside of the main body housing 2 and provided with a ventilation louver 231, a first rib 232 extending from the ventilation louver 231 toward the inside of the main body housing 2, a temperature and humidity sensor 91 positioned to overlap with the vent 23a when viewed from the left and right directions, and a second rib 811 extending from inside the main body housing 2 toward the left side cover 23 and facing the first rib 232, wherein the first distance L1 between the first rib 232 and the second rib 811 in the left and right directions is smaller than the second distance L2 between the temperature and humidity sensor 91 and the left side cover 23.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] Conventionally, as disclosed in Patent Document 1, there is known an image forming apparatus including a main body housing having a cover formed with a ventilation hole and an environmental sensor for detecting environmental conditions around the main body housing.

[0003] In the image forming apparatus disclosed in Patent Document 1, the environmental sensor is disposed near the ventilation hole.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, in a configuration in which a ventilation hole is formed in the cover, the strength around the portion where the ventilation hole of the cover is formed tends to decrease. Therefore, when the image forming apparatus falls or the like, the periphery of the portion where the ventilation hole of the cover is formed may be deformed and come into contact with the environmental sensor, and the environmental sensor may be damaged.

[0006] Therefore, in the present invention, there is provided an image forming apparatus capable of suppressing damage to the environmental sensor even when the environmental sensor for detecting environmental conditions around the main body housing is disposed near the ventilation hole formed in the cover.

Means for Solving the Problems

[0007] The image forming apparatus for solving the above problems has the following features.

[0008] That is, the image forming apparatus comprises a main body housing that houses an image forming unit for forming an image on a sheet; a cover that constitutes the first surface of the main body housing; a fan that exhausts air from inside the main body housing or draws air into the main body housing; a vent formed in the cover at a position not facing the fan and communicating the inside of the main body housing with the outside of the main body housing, the vent being provided with a louver; a first rib extending from the louver toward the inside of the main body housing; an environmental sensor positioned to overlap with the vent when viewed from a first direction perpendicular to the first surface and for detecting the environmental conditions around the main body housing; and a second rib extending from inside the main body housing toward the cover and facing the first rib, wherein the first distance between the first rib and the second rib in the first direction is smaller than the second distance between the environmental sensor and the cover in the first direction.

[0009] This prevents damage to the environmental sensor from occurring due to contact between the cover and the sensor in the event of the image forming apparatus being dropped or for other reasons. In particular, it can prevent damage to the environmental sensor even when it is placed near a ventilation opening formed in the cover.

[0010] Furthermore, it has a grounded metal piece positioned closer to the cover than the environmental sensor.

[0011] This prevents damage to the environmental sensor caused by static electricity entering the main unit's casing from the outside.

[0012] Furthermore, the first distance between the first rib and the second rib in the first direction is smaller than the third distance between the metal piece and the cover in the first direction.

[0013] This prevents the metal fragment from coming into contact with the cover during a fall or other incident, thus preventing the metal fragment from deforming or breaking.

[0014] Furthermore, the environmental sensor and the metal piece are positioned so that they overlap when viewed from the first direction.

[0015] This can effectively prevent the electrostatic charge that has entered the main body housing from the outside from damaging the environmental sensor.

[0016] Also, it has a sensor substrate that holds the environmental sensor and the metal piece.

[0017] This can suppress the displacement of the metal piece with respect to the environmental sensor.

[0018] Also, it has a holding frame that holds the sensor substrate and on which the second rib is formed.

[0019] This can improve the accuracy of the magnitude relationship among the first distance between the first rib and the second rib, the second distance between the environmental sensor and the cover, and the third distance between the metal piece and the cover.

[0020] [[ID=二十一]]Also, the holding frame has a third rib that extends toward the cover, and an elastic member is sandwiched between the third rib and the cover. [[ID=二十二]] [[ID=二十三]]

[0021] [[ID=二十四]] [[ID=二十五]]This can effectively prevent the cover from contacting the environmental sensor and the metal piece when the image forming apparatus drops or the like, by the third rib and the cover contacting each other through the elastic member. [[ID=二十六]] [[ID=二十七]]

[0022] [[ID=二十八]] [[ID=二十九]]Also, the fourth distance between the third rib and the cover in the first direction is smaller than the third distance between the metal piece and the cover in the first direction. [[ID=三十]] [[ID=三十一]]

[0023] [[ID=三十二]] [[ID=三十三]]This can prevent the metal piece from contacting the cover and being deformed or damaged. [[ID=三十四]] [[ID=三十五]]

[0024] [[ID=三十六]] [[ID=三十七]]Also, it further includes an electrical component that drives a roller for conveying a sheet, and the second rib is located between the environmental sensor and the electrical component in a direction orthogonal to the direction in which the second rib extends. [[ID=三十八]] [[ID=三十九]]

[0025] [[ID=四十]] Thereby, heat generated by the electrical component can be shielded by the second rib, and heat transfer from the electrical component to the environmental sensor can be suppressed.

[0026] Also, the electrical component is an electromagnetic clutch for switching the transmission and interruption of driving force.

[0027] Thereby, heat generated by the electromagnetic clutch can be shielded by the second rib, and heat transfer from the electromagnetic clutch to the environmental sensor can be suppressed, preventing the detection accuracy of environmental conditions by the environmental sensor from decreasing.

[0028] Also, the environmental sensor is a temperature and humidity sensor.

[0029] Thereby, when the image forming apparatus drops or the like, contact between the cover and the temperature and humidity sensor can be suppressed, preventing damage to the temperature and humidity sensor. [[ID=十七]]

[0030] Also, the first surface is a side surface of the main body housing. <0000%107> Thereby, when the image forming apparatus drops or the like, contact between the cover constituting the side surface of the main body housing and the environmental sensor can be suppressed, preventing damage to the environmental sensor.

[0032] Also, the first surface is located on the opposite side of the fan across the image forming unit in the first direction. <000%112>

[0033] Thereby, the ventilation port of the cover and the opening facing the fan are provided on opposite side surfaces, and a decrease in the strength of the cover can be suppressed.

Advantages of the Invention

[0034] According to the present invention, when the image forming apparatus drops or the like, contact between the cover and the environmental sensor can be suppressed, preventing damage to the environmental sensor. In particular, even when the environmental sensor is disposed near the ventilation port formed in the cover, damage to the environmental sensor can be suppressed.

Brief Description of the Drawings

[0035] [Figure 1] This is a central cross-sectional view showing an image forming apparatus. [Figure 2] This is a perspective view of the image forming apparatus from the front right side. [Figure 3] This is a perspective view of the image forming apparatus from the front left side. [Figure 4] This is a perspective view showing the ventilation louvers. [Figure 5] This is a side view showing the left frame to which the retaining frame, sensor board, and electromagnetic clutch are attached. [Figure 6] This is a perspective view showing the left frame with the retaining frame, sensor board, and electromagnetic clutch attached. [Figure 7] This is a side view showing the positional relationship between the temperature and humidity sensor and the vent. [Figure 8] This is a rear cross-sectional view showing the temperature and humidity sensor, metal piece, second rib, and third rib on the left frame side, and the inner surface, first rib, and opposing rib on the left side cover side. [Figure 9] This is a perspective view showing the inner surface of the left side cover, the first rib, and the opposing rib. [Figure 10] This is a side cross-sectional view showing the positional relationship between the temperature and humidity sensor, metal piece, second rib, third rib, and large electromagnetic clutch on the left frame side, and the first rib and opposing rib on the left side cover side. [Figure 11] This is a front cross-sectional view showing the second rib, third rib, and electromagnetic clutch on the left frame side, and the inner surface, first rib, and opposing rib on the left side cover side. [Figure 12] This is a rear cross-sectional view showing the positional relationship between each rib, temperature and humidity sensor, and metal piece. [Modes for carrying out the invention]

[0036] Next, embodiments for carrying out the present invention will be described with reference to the attached drawings.

[0037] [Image forming apparatus] The image forming apparatus 1 shown in Figures 1 to 3 is an embodiment of the image forming apparatus according to the present invention, and is a color laser printer that forms a multi-color image on a sheet S using an electrophotographic method.

[0038] In the following explanation, the left side of Figure 1 is defined as the front side of the image forming apparatus 1, and the right side of Figure 1 is defined as the rear side of the image forming apparatus 1. The front side of the paper in Figure 1 is defined as the right side of the image forming apparatus 1, and the back side of the paper in Figure 1 is defined as the left side of the image forming apparatus 1. Furthermore, the top and bottom sides of Figure 1 are defined as the top and bottom sides of the image forming apparatus 1, respectively.

[0039] The image forming apparatus 1 comprises a main body housing 2, a paper feeding unit 3 equipped with a paper feed tray 10 for supporting a sheet S and a sheet transport unit 30 for transporting the sheet S, and an image forming unit 5 for forming an image on the sheet S transported by the paper feeding unit 3.

[0040] The main housing 2 is formed in a roughly rectangular parallelepiped shape and houses the paper feeding section 3 and the image forming section 5. The front of the main housing 2 has a front opening 2A, and the main housing 2 is equipped with a front cover 21 that can open and close the front opening 2A.

[0041] The front cover 21 is configured to rotate around a pivot axis 21a at its lower end, and by rotating around the pivot axis 21a, it can move between a closed position that closes the front opening 2A and an open position that opens the front opening 2A. A paper output tray 22 is formed on the upper surface of the main body housing 2, which slopes downward from the front to the rear.

[0042] The paper feeding unit 3 is located at the bottom of the main body housing 2 and transports the sheet S, supported by the paper feeding tray 10, to the image forming unit 5 via the sheet transport unit 30. The paper feeding tray 10 is configured to slide in the front-to-back direction and is movable between a storage position where it is housed in the main body housing 2 and a detached position where it is pulled forward from the storage position.

[0043] The sheet transport unit 30 includes a paper feed roller 32, a separation roller 33, a separation pad 33a, a transport roller pair 34, and a registration roller pair 35. Inside the main housing 2, a transport path P for sheets S is configured, which goes from the paper feed tray 10 through the image forming unit 5 to the paper output tray 22.

[0044] The sheets S supported in the paper feed tray 10 are separated one by one by the paper feed roller 32, the separation roller 33, and the separation pad 33a, and then sent to the transport path P. The paper feed roller 32 is a roller for transporting the sheets S from the paper feed tray 10 toward the image forming unit 5. The separation roller 33 and the separation pad 33a constitute a separation means for separating the sheets S supported in the paper feed tray 10 one by one.

[0045] The sheet S, which has been sent onto the transport path P, is transported toward the image forming unit 5 by the transport roller pair 34 and the resist roller pair 35. The resist roller pair 35 restricts the movement of the leading edge of the transported sheet S, stopping it temporarily, and then transports the sheet S toward the image forming unit 5 at a predetermined timing.

[0046] The image forming unit 5 is located above the paper feeding unit 3 and includes four toner cartridges 50 arranged in a front-to-back direction, and a photosensitive drum 51 corresponding to each toner cartridge 50. Each toner cartridge 50 corresponds to yellow, magenta, cyan, and black. The toner cartridges 50 are detachably supported in a drawer 59. The drawer 59 can be attached to and detached from the main body housing 2 through the front opening 2A of the main body housing 2 by opening the front cover 21. Each toner cartridge 50 is equipped with a developing roller 52.

[0047] The photosensitive drum 51 is formed in a substantially cylindrical shape with its axis running in the left-right direction and is rotatably supported by the drawer 59. The developing roller 52 extends in the left-right direction and is rotatably supported by the toner cartridge 50. Toner is an example of a developer. The developing roller 52 supplies toner to the photosensitive drum 51.

[0048] The main housing 2 includes an exposure device 56 for exposing the surface of the photosensitive drum 51. The exposure device 56 includes a laser diode, a polarizer, a lens, and a mirror (not shown). The exposure device 56 is configured to emit a light beam to each photosensitive drum 51 and expose the surface of each photosensitive drum 51.

[0049] Below the transport path P of the photosensitive drum 51, a transfer belt 41 is positioned opposite. The transfer belt 41 is in contact with the photosensitive drum 51. The transfer belt 41 is stretched between a drive roller 42 and a driven roller 43 positioned in front of the drive roller 42. Transfer rollers 44 are positioned opposite each photosensitive drum 51 on either side of the transfer belt 41. In the image forming unit 5, the belt device 40 is composed of the transfer belt 41, drive roller 42, driven roller 43, and transfer rollers 44, etc.

[0050] The image forming unit 5 is equipped with a charger 54 for charging each photosensitive drum 51. The charger 54 is supported by a drawer 59. The photosensitive drums 51, uniformly charged by the charger 54, are selectively exposed by the exposure device 56. This exposure selectively removes charge from the surface of the photosensitive drum 51, forming an electrostatic latent image on the surface of the photosensitive drum 51.

[0051] The toner contained in the toner cartridge 50 is positively charged and carried on the surface of the developing roller 52. A developing bias is applied to the developing roller 52, and when the electrostatic latent image formed on the photosensitive drum 51 faces the developing roller 52, toner is supplied from the developing roller 52 to the electrostatic latent image due to the potential difference between the electrostatic latent image and the developing roller 52. As a result, a toner image is formed on the surface of the photosensitive drum 51.

[0052] When the sheet S, which has been transported toward the image forming unit 5, reaches the transfer belt 41, it is transported by the transfer belt 41 and passes sequentially between the transfer belt 41 and each photosensitive drum 51. Then, when the toner image supported on the surface of the photosensitive drum 51 comes into contact with the sheet S, it is transferred to the sheet S by the transfer bias applied to the transfer roller 44.

[0053] In this embodiment, the transfer belt 41 is configured as a transport belt that transports the sheet S to which the toner image is transferred. However, it is also possible to configure it as an intermediate transfer belt to which the toner image is transferred to the belt itself, and the toner image transferred to the belt is further transferred to the sheet S.

[0054] The sheet S onto which the toner image has been transferred is transported to the fuser unit 60. The fuser unit 60 is equipped with a heating roller 61 and a pressure roller 62 that presses against the heating roller 61. As the sheet S transported to the fuser unit 60 passes between the heating roller 61 and the pressure roller 62, the toner image is heat-fixed. In other words, the fuser unit 60 fixes the toner image onto the sheet S.

[0055] The sheet S on which the toner image has been heat-fixed is transported downstream from the fuser 60 in the transport direction, and further transported by the intermediate paper discharge roller pair 63 and the paper discharge roller pair 64 located downstream of the intermediate paper discharge roller pair 63 in the transport direction, and discharged into the paper discharge tray 22.

[0056] In the image forming apparatus 1, a process unit PU is configured to form a toner image on the sheet S, comprising a drawer 59, a toner cartridge 50 supported by the drawer 59, a photosensitive drum 51, and a charger 54, etc. The process unit PU only needs to include at least a photosensitive drum 51 and a charger 54, and may also include a transfer belt 41 or a fuser 60.

[0057] The image forming apparatus 1 includes a power supply board 11 on which a power supply circuit is formed, and a board cover 12 that covers the power supply board 11. The board cover 12 is located between the paper feed tray 10 and the belt device 40 at the rear of the main housing 2. The main housing 2 houses the process unit PU and the board cover 12.

[0058] As shown in Figures 2 and 3, the main housing 2 contains a left frame 25 and a right frame 26. The left frame 25 and the right frame 26 are spaced apart in the left-right direction. The left frame 25 is located at the left end of the main housing 2 and extends in the front-rear and up-down directions. The right frame 26 is located at the right end of the main housing 2 and extends in the front-rear and up-down directions.

[0059] In the left-right direction, the left frame 25 is located to the left of the image forming unit 5, and the right frame 26 is located to the right of the image forming unit 5. In other words, in the left-right direction, the left frame 25 is located on the opposite side of the image forming unit 5 from the right frame 26.

[0060] As shown in Figures 1 to 3, the image forming apparatus 1 is equipped with a first fan 71 and a second fan 72 that exhaust air from inside the main housing 2 to the outside of the main housing 2. The first fan 71 and the second fan 72 are supported by the right frame 26.

[0061] The left frame 25 supports a sensor board 73 on which a temperature and humidity sensor 91 (see Figures 5 and 6) is mounted, and a control board 74 to which detection signals from the temperature and humidity sensor 91 are input. The temperature and humidity sensor 91 is an environmental sensor for detecting the environmental conditions around the main body housing 2. The temperature and humidity sensor 91 detects the temperature and humidity, which are the environmental conditions around the main body housing 2. The sensor board 73 holds the temperature and humidity sensor 91. The sensor board 73 and the control board 74 are supported on the left side of the left frame 25.

[0062] [First fan and second fan] As shown in Figures 1 and 2, the first fan 71 is positioned to the right and rear of the process unit PU inside the main housing 2. The first fan 71 is configured to exhaust the air inside the process unit PU inside the main housing 2 to the outside of the main housing 2.

[0063] The second fan 72 is positioned to the right of the circuit board cover 12 within the main body casing 2, and in the left-right direction, such that the projection surface of the second fan 72 directed toward the circuit board cover 12 overlaps with the rear of the circuit board cover 12. The second fan 72 is configured to exhaust the air inside the circuit board cover 12 from the main body casing 2 to the outside. The second fan 72 is located below the first fan 71.

[0064] [Right side cover of the main unit] As shown in Figure 2, the main housing 2 is equipped with a right side cover 24 that covers the right side of the right frame 26. The right side cover 24 constitutes the right side of the main housing 2. The right side cover 24 of the main housing 2 is equipped with a first exhaust port 24a and a second exhaust port 24b that penetrate the right side cover 24 in the left-right direction.

[0065] The second exhaust port 24b is positioned vertically alongside the first exhaust port 24a. Both the first exhaust port 24a and the second exhaust port 24b are located at the rear of the right side cover 24, with the first exhaust port 24a located above the second exhaust port 24b.

[0066] The main housing 2 includes a first exhaust louver 241 positioned at the first exhaust port 24a and a second exhaust louver 242 positioned at the second exhaust port 24b. The first exhaust louver 241 is located to the right of the first fan 71, and the second exhaust louver 242 is located to the right of the second fan 72. In this embodiment, the first exhaust louver 241 and the second exhaust louver 242 are formed by integral molding with the right side cover 24.

[0067] The first fan 71 is positioned such that the projection surface of the first fan 71 projected toward the right side cover 24 in the left-right direction coincides with the first exhaust port 24a. The first exhaust port 24a is an opening facing the first fan 71. When the first fan 71 is driven, an airflow is generated in the direction from left to right, and the airflow created by the first fan 71 exhausts the air inside the process unit PU to the outside of the main body housing 2 through the first exhaust louver 241 located at the first exhaust port 24a.

[0068] The second fan 72 is positioned such that the projection surface of the second fan 72 projected toward the right side cover 24 in the left-right direction coincides with the second exhaust port 24b. The second exhaust port 24b is an opening facing the second fan 72. When the second fan 72 is driven, an airflow is generated from left to right, and the airflow created by the second fan 72 exhausts the air inside the circuit board cover 12 to the outside of the main body housing 2 through the second exhaust louver 242 located at the second exhaust port 24b.

[0069] In this embodiment, the first fan 71 and the second fan 72 are fans that exhaust air from inside the main body housing 2, but they can also be configured as fans that draw air into the main body housing 2. The first fan 71 and the second fan 72 are examples of fans that exhaust air from inside the main body housing or draw air into the main body housing.

[0070] [Left side cover of the main unit] As shown in Figure 3, the main casing 2 is equipped with a left side cover 23 that covers the left side of the left frame 25. The left side cover 23 constitutes the left side of the main casing 2. The left side of the main casing 2 is an example of a first surface, which is a side surface of the main casing. The left side cover 23 is an example of a cover that constitutes the first surface of the main casing.

[0071] The left side cover 23 is located on the opposite side of the image forming unit 5 from the first fan 71 and the second fan 72 in the left-right direction. In other words, the image forming unit 5 is located between the left side cover 23 and the first fan 71 and the second fan 72 in the left-right direction. The left-right direction is an example of a first direction perpendicular to the first surface of the main body housing.

[0072] The left side cover 23 of the main body housing 2 is equipped with a ventilation opening 23a that penetrates the left side cover 23 in the left-right direction. The ventilation opening 23a is located at the front and bottom of the left side cover 23. The ventilation opening 23a connects the inside of the main body housing 2 to the outside of the main body housing 2. The temperature and humidity of the air that enters the main body housing 2 from the outside of the main body housing 2 through the ventilation opening 23a is detected by the temperature and humidity sensor 91.

[0073] The ventilation opening 23a is formed in a position that does not face the first fan 71 and the second fan 72 in the left-right direction. In other words, the ventilation opening 23a is formed in a position that does not overlap with the first fan 71 and the second fan 72 when viewed from the left-right direction.

[0074] The main housing 2 is equipped with ventilation louvers 231 positioned in the ventilation opening 23a. The ventilation louvers 231 are an example of louvers provided in a ventilation opening.

[0075] As shown in Figure 4, the ventilation louver 231 comprises a rectangular frame 231a formed along the periphery of the ventilation opening 23a, and vanes 231b extending in the front-rear direction within the area enclosed by the frame 231a. Multiple vanes 231b are arranged at intervals in the vertical direction. In this embodiment, the ventilation louver 231 is formed by integral molding with the left side cover 23.

[0076] The portion of the left side cover 23 where the ventilation opening 23a is formed tends to have lower strength compared to the portion where the ventilation opening 23a is not formed. Similarly, the portion of the right side cover 24 where the first exhaust port 24a and the second exhaust port 24b are formed tends to have lower strength compared to the portion where the first exhaust port 24a and the second exhaust port 24b are not formed.

[0077] However, since the left side cover 23 is located on the opposite side from the first fan 71 and the second fan 72, with the image forming unit 5 in between, the first exhaust port 24a and the second exhaust port 24b, which face the first fan 71 and the second fan 72, and the ventilation port 23a are not formed on the same side of the main body housing 2.

[0078] In other words, the ventilation opening 23a and the first exhaust opening 24a and second exhaust opening 24b are formed on the opposite side of the main housing 2. This makes it possible to suppress a decrease in the strength of the left side cover 23 and the right side cover 24 that make up the side of the main housing 2.

[0079] [Left frame] (Motor and electromagnetic clutch) As shown in Figures 5 and 6, the image forming apparatus 1 is equipped with a motor 75 and an electromagnetic clutch 76. The motor 75 drives rollers for transporting the sheet S, such as the paper feed roller 32. The electromagnetic clutch 76 is an electrical component that switches between transmitting and interrupting the driving force from the motor 75 to the paper feed roller 32, etc., and generates heat when in operation.

[0080] The motor 75 and the electromagnetic clutch 76 are supported on the left side of the left frame 25. The motor 75 is located in the center of the left frame 25 in the front-rear direction, and the electromagnetic clutch 76 is located in front of the motor 75.

[0081] (Holding frame) The image forming apparatus 1 includes a holding frame 81 for holding the sensor substrate 73. The holding frame 81 is supported on the left side of the left frame 25. In other words, the sensor substrate 73 is supported by the left frame 25 via the holding frame 81.

[0082] (Positional relationship between the temperature and humidity sensor and the vent) As shown in Figure 7, the temperature and humidity sensor 91 held on the sensor substrate 73 is positioned so as to overlap with the vent 23a when viewed from the left and right directions, and is located in the vicinity of the vent 23a.

[0083] Therefore, when the temperature and humidity sensor 91 detects the temperature and humidity of the air that has entered the main unit housing 2 through the ventilation opening 23a from outside the main unit housing 2, it can detect the temperature and humidity of the air from outside the main unit housing 2 before it is affected by the environment inside the main unit housing 2. As a result, the temperature and humidity sensor 91 can detect the temperature and humidity around the main unit housing 2 with high accuracy.

[0084] (metal piece) As shown in Figures 5, 6, and 8, the image forming apparatus 1 includes a metal piece 82 that covers the temperature and humidity sensor 91 held on the sensor substrate 73. The metal piece 82 is grounded.

[0085] The metal piece 82 has a fixing portion 82a that is fixed to the sensor substrate 73, an upper covering portion 82b that covers the top of the temperature and humidity sensor 91, a left covering portion 82c that covers the left side of the temperature and humidity sensor 91, and a lower covering portion 82d that covers the bottom of the temperature and humidity sensor 91.

[0086] The metal piece 82 is held in place by the fixing portion 82a being fixed to the sensor substrate 73. The temperature and humidity sensor 91 and the metal piece 82 are positioned so that they overlap when viewed from the left-right direction.

[0087] The metal piece 82 is positioned in front of the motor 75 and behind the electromagnetic clutch 76 in the front-rear direction. The left covering portion 82c of the metal piece 82 is positioned between the temperature and humidity sensor 91 and the left side cover 23 in the left-right direction. In other words, the left covering portion 82c is positioned closer to the left side cover 23 than to the temperature and humidity sensor 91 in the left-right direction. The left covering portion 82c of the metal piece 82 faces the left side cover 23 with a gap between them in the left-right direction.

[0088] The metal piece 82 is formed by bending a sheet metal member, and the fixing portion 82a is positioned parallel to the sensor substrate 73. The fixing portion 82a is grounded by being fixed to the sensor substrate 73. The upper covering portion 82b extends to the left from the lower end of the fixing portion 82a. The left covering portion 82c extends downward from the left end of the upper covering portion 82b. The lower covering portion 82d extends to the right from the lower end of the left covering portion 82c.

[0089] The metal piece 82, with its upper covering portion 82b, left covering portion 82c, and lower covering portion 82d covering the temperature and humidity sensor 91, prevents static electricity from reaching the temperature and humidity sensor 91 when static electricity enters the main body housing 2 from the outside through the ventilation opening 23a. This prevents damage to the temperature and humidity sensor 91 caused by static electricity entering the main body housing 2 from the outside.

[0090] In this case, since the temperature and humidity sensor 91 and the metal piece 82 are positioned to overlap when viewed from the left and right, it is possible to effectively suppress damage to the temperature and humidity sensor 91 caused by static electricity entering the main body housing 2 from the outside.

[0091] Furthermore, since both the temperature and humidity sensor 91 and the metal piece 82 are held by the retaining frame 81, misalignment of the metal piece 82 relative to the temperature and humidity sensor 91 can be suppressed, and damage to the temperature and humidity sensor 91 due to static electricity can be more effectively suppressed.

[0092] [First rib and opposing rib] As shown in Figures 8 to 11, the left side cover 23 has an inner surface 23A facing to the right. The left side cover 23 has a first rib 232 and an opposing rib 233. The first rib 232 and the opposing rib 233 protrude to the right from the inner surface 23A of the left side cover 23.

[0093] The first rib 232 is formed on the inner surface 23A of the left side cover 23 in the portion where the ventilation louvers 231 are formed. In other words, the first rib 232 extends from the ventilation louvers 231 into the main body housing 2.

[0094] Multiple first ribs 232 are arranged at intervals in the vertical direction. In the front-rear direction, the first ribs 232 are located between the metal piece 82 and the temperature and humidity sensor 91 and the electromagnetic clutch 76.

[0095] The opposing rib 233 is formed on the inner surface 23A of the left side cover 23, at a position above the portion where the first rib 232 is formed. The rightward projection length of the opposing rib 233 is smaller than the rightward projection length of the first rib 232.

[0096] [Second rib and third rib] As shown in Figures 5-8, 10, and 11, the retaining frame 81 has a second rib 811 and a third rib 812 that project to the left. The third rib 812 is located above the second rib 811. The leftward projection length of the third rib 812 is greater than the leftward projection length of the second rib 811.

[0097] The second rib 811 and the third rib 812 are located in the longitudinal direction between the metal piece 82 and the temperature and humidity sensor 91 and the electromagnetic clutch 76. The longitudinal direction is an example of a direction perpendicular to the direction in which the second rib extends.

[0098] The second rib 811, which extends from the retaining frame 81 toward the left side cover 23, is positioned between the temperature and humidity sensor 91 and the electromagnetic clutch 76, thereby shielding the heat generated by the electromagnetic clutch 76. This prevents heat from the electromagnetic clutch 76, which is an electrical component, from being transferred to the temperature and humidity sensor 91, thus suppressing a decrease in the accuracy of heat and humidity detection by the temperature and humidity sensor 91.

[0099] The second rib 811 extends from the retaining frame 81 located inside the main housing 2 toward the left side cover 23. The second rib 811 formed on the retaining frame 81 faces the first rib 232 of the left side cover 23 with a gap between them in the left-right direction.

[0100] The third rib 812 extends from the retaining frame 81 located inside the main housing 2 toward the left side cover 23. The third rib 812 formed on the retaining frame 81 faces the opposing rib 233 of the left side cover 23 with a gap between them in the left-right direction.

[0101] An elastic member 83, such as a sponge, is interposed between the third rib 812 and the opposing rib 233. The elastic member 83 is sandwiched between the third rib 812 and the opposing rib 233.

[0102] [Positional relationship between each rib, temperature and humidity sensor, and metal piece] As shown in Figure 12, the first rib 232 and the second rib 811 are located at a distance of first distance L1 in the left-right direction. The temperature and humidity sensor 91 and the inner surface 23A of the left side cover 23 are located at a distance of second distance L2 in the left-right direction.

[0103] The metal piece 82 and the inner surface 23A of the left side cover 23 are located at a distance of a third distance L3 in the left-right direction. The third rib 812 and the opposing rib 233 of the left side cover 23 are located at a distance of a fourth distance L4 in the left-right direction.

[0104] The first distance L1 between the first rib 232 and the second rib 811 is formed to be smaller than the second distance L2 between the temperature and humidity sensor 91 and the left side cover 23 (L1 < L2). Here, when the image forming apparatus 1 drops or the like, there is a possibility that the periphery of the portion where the ventilation hole 23a of the left side cover 23 is formed may be deformed.

[0105] When the left side cover 23 is deformed inward of the main body housing 2, since the first distance L1 is formed to be smaller than the second distance L2, the first rib 232 and the second rib 811 come into contact with each other before the temperature and humidity sensor 91 and the left side cover 23 come into contact with each other.

[0106] Thereby, further deformation of the left side cover 23 is suppressed, and contact between the temperature and humidity sensor 91, which is an environmental sensor, and the left side cover 23 that constitutes the left side surface of the main body housing 2 is prevented, and it is possible to suppress breakage of the temperature and humidity sensor 91, which is an environmental sensor.

[0107] Particularly, even when the temperature and humidity sensor 91, which is an environmental sensor, is disposed in the vicinity of the ventilation hole 23a formed in the left side cover 23 as in the image forming apparatus 1, breakage of the temperature and humidity sensor 91 can be suppressed.

[0108] Also, the first distance L1 between the first rib 232 and the second rib 811 is formed to be smaller than the third distance L3 between the metal piece 82 and the left side cover 23 (L1 < L3). Therefore, when the image forming apparatus 1 drops or the like and the left side cover 23 is deformed inward of the main body housing 2, the first rib 232 and the second rib 811 come into contact with each other before the metal piece 82 and the left side cover 23 come into contact with each other.

[0109] Thereby, further deformation of the left side cover 23 is suppressed, and contact between the metal piece 82 and the left side cover 23 is prevented, and it is possible to suppress deformation or breakage of the metal piece 82.

[0110] The third rib 812 and the opposing rib 233 of the left side cover 23 are positioned apart from each other by a fourth distance L4 in the left-right direction, and the elastic member 83 is sandwiched between the third rib 812 and the opposing rib 233.

[0111] Therefore, when the image forming apparatus 1 drops or the like, it is possible to effectively suppress the left side cover 23 from contacting the humidity and temperature sensor 91 and the metal piece 82 via the elastic member 83 when the third rib 812 and the left side cover 23 contact each other.

[0112] Furthermore, the fourth distance L4 between the third rib 812 and the left side cover 23 is formed to be smaller than the third distance L3 between the metal piece 82 and the left side cover 23 (L4 < L3). Therefore, when the image forming apparatus 1 drops or the like and the left side cover 23 is deformed inward of the main body housing 2, the third rib 812 and the left side cover 23 contact each other via the elastic member 83 before the metal piece 82 and the left side cover 23 contact each other.

[0113] Thereby, further deformation of the left side cover 23 is suppressed, and it is possible to suppress the metal piece 82 and the left side cover 23 from contacting each other and the metal piece 82 from being deformed or damaged.

[0114] Also, the fourth distance L4 between the third rib 812 and the left side cover 23 is formed to be smaller than the first distance L1 between the second rib 811 formed on the holding frame 81 and the first rib 232 (L4 < L1). Therefore, when the image forming apparatus 1 drops or the like and the left side cover 23 is deformed inward of the main body housing 2, the third rib 812 and the left side cover 23 contact each other via the elastic member 83 before the first rib 232 and the second rib 811 contact each other.

[0115] As a result, the image forming apparatus 1 can suppress impacts such as drops and deformation of the side cover 23 in two stages: contact between the side cover 23 and the third rib 812, and contact between the first rib 232 and the second rib. This effectively suppresses contact between the left side cover 23 and the temperature sensor 91 and the metal piece 82. In addition, the elastic member 83 can suppress the generation of tapping noises.

[0116] Furthermore, the retaining frame 81 on which the second rib 811 and the third rib 812 are formed holds the sensor substrate 73. Therefore, it is possible to improve the accuracy of the size relationship between the first distance L1 between the second rib 811 and the first rib 232 formed on the retaining frame 81, the second distance L2 between the temperature and humidity sensor 91 held on the sensor substrate 73 and the left side cover 23, the third distance L3 between the metal piece 82 held on the sensor substrate 73 and the left side cover 23, and the fourth distance L4 between the third rib 812 formed on the retaining frame 81 and the left side cover 23. [Explanation of Symbols]

[0117] 1. Image forming apparatus 2 Main unit 5 Image forming unit 23 Left side cover 23a Ventilation opening 32 Paper feed rollers 71 First Fan 72 Second Fan 73 Sensor board 76 Electromagnetic clutch 81 Retaining frame 82 Metal piece 83 Elastic members 91 Temperature and Humidity Sensor 231 Ventilation Louvers 232 First Rib 233 Opposing Ribs 811 2nd Rib 813 Third Rib L1 1st distance L2 2nd distance L3 3rd distance L4 4th distance S Seat

Claims

1. A main housing that houses an image forming unit that forms an image on a sheet, The cover that constitutes the first surface of the main body housing, A fan that exhausts air from or draws air into the main body housing, A ventilation opening formed in the cover at a position not facing the fan, which connects the inside of the main body housing to the outside of the main body housing, and which is provided with a louver, A first rib extending from the louver toward the interior of the main housing, An environmental sensor is positioned to detect the surrounding environmental conditions of the main housing, and is located in a position that overlaps with the ventilation opening when viewed from a first direction perpendicular to the first surface. A second rib extends from inside the main housing toward the cover and faces the first rib, Equipped with, An image forming apparatus in which the first distance between the first rib and the second rib in the first direction is smaller than the second distance between the environmental sensor and the cover in the first direction.

2. The image forming apparatus according to claim 1, having a grounded metal piece positioned closer to the cover than the environmental sensor.

3. The image forming apparatus according to claim 2, wherein the first distance between the first rib and the second rib in the first direction is smaller than the third distance between the metal piece and the cover in the first direction.

4. The image forming apparatus according to claim 2, wherein the environmental sensor and the metal piece are arranged in positions that overlap when viewed from the first direction.

5. An image forming apparatus according to any one of claims 2 to 4, comprising a sensor substrate for holding the environmental sensor and the metal piece.

6. The image forming apparatus according to claim 5, having a holding frame that holds the sensor substrate and on which the second rib is formed.

7. The image forming apparatus according to claim 6, wherein the retaining frame has a third rib extending toward the cover, and the elastic member is sandwiched between the third rib and the cover.

8. The image forming apparatus according to claim 7, wherein the fourth distance between the third rib and the cover in the first direction is smaller than the third distance between the metal piece and the cover in the first direction.

9. It further includes electrical components that drive rollers for transporting the sheets, The image forming apparatus according to claim 1, wherein the second rib is located between the environmental sensor and the electrical component in a direction perpendicular to the direction in which the second rib extends.

10. The image forming apparatus according to claim 9, wherein the electrical component is an electromagnetic clutch for switching between transmitting and interrupting driving force.

11. The image forming apparatus according to claim 1, wherein the environmental sensor is a temperature and humidity sensor.

12. The image forming apparatus according to claim 1, wherein the first surface is the side surface of the main body housing.

13. The image forming apparatus according to claim 12, characterized in that the first surface is located on the opposite side of the fan from the image forming unit in the first direction.

Images