JP2009069319A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of protecting a circuit or the like connected to a fan motor from static electricity by performing destaticization with a simple configuration. <P>SOLUTION: In the image forming apparatus equipped with the fan motor 34 driving and rotating a cooling fan, a wire spring for destaticization 35 is wound round the motor fan 34, and one end of the wire spring 35 is locked on a fan case 33 and the other end is locked on a sheet metal frame (main body frame) 31. An e-shaped part 35a having nearly the same diameter as the outside diameter of the fan motor 34 is formed in the center part of the wire spring 35, and is fit in the outer periphery of the fan motor 34. Furthermore, one end of the wire spring 35 is bent in J-shape and the bent part is made to pass through a machine screw insertion hole 33a formed on the fan case 33 and locked on the periphery of the machine screw insertion hole 33a of the fan case 33. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus including a fan motor that rotationally drives a cooling fan.

  In an image forming apparatus such as a copying machine, a printer, or a facsimile that forms an image on a sheet by electrophotography, an electrostatic latent image formed on an image carrier such as a photosensitive drum is developed by a developing device to form a toner image. The toner image is visualized, and the toner image is transferred onto a sheet fed at an appropriate timing by a transfer device. Then, the sheet on which the toner image is transferred is conveyed to a fixing device, and after the toner image is fixed by the fixing device, it is discharged outside the apparatus.

  In such an image forming apparatus, if the temperature inside the main body rises due to heat generated from the fixing device or the like, various problems such as toner melting occur, and therefore the outside air is introduced into the main body by a cooling fan to cool the inside of the main body. To be done.

By the way, Patent Document 1 proposes a static eliminator for neutralizing charges of a positively or negatively charged charged body such as an ionizer (ionizer).
JP 2004-253193 A

  In recent years, as an image forming apparatus such as a copying machine or a printer is downsized, a fan motor is disposed in the vicinity of the exterior, and an opening area of the outside air introduction port is reduced in order to prevent a decrease in cooling efficiency due to the exterior louver. The ratio of the opening area to the exterior area (opening ratio) is set to be large. For this reason, the fan motor is easily affected by static electricity, and a countermeasure for protecting the fan motor from static electricity has been desired.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image forming apparatus capable of removing static electricity with a simple configuration and protecting a circuit and the like connected to a fan motor from static electricity. is there.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided an image forming apparatus comprising a fan motor that rotationally drives a cooling fan, wherein a wire spring for discharging is wound around the motor fan, and one end of the wire spring is connected to the fan. It is locked to the case, and the other end is locked to the main body frame.

  According to a second aspect of the present invention, in the first aspect of the present invention, a "" "-shaped part having a diameter substantially equal to the outer diameter of the fan motor is formed at the center of the wire spring. A character-shaped portion is fitted on the outer periphery of the fan motor.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein one end of the wire spring is bent in a J shape, and the bent portion is passed through a screw insertion hole formed in the fan case. It is characterized by being locked to the periphery of the insertion hole.

  According to the first and second aspects of the present invention, a wire spring for discharging is wound around the fan motor, one end of the wire spring is locked to the fan case, and the other end is locked to the main body frame. It can be easily assembled, and the wire spring can effectively remove static electricity and reliably protect the circuit connected to the fan motor from static electricity.

  According to the third aspect of the present invention, the wire spring can be easily assembled with one touch by passing one end of the wire spring bent in a J-shape through the screw insertion hole of the fan case and engaging the periphery of the screw insertion hole. Can do. Also, if the fan motor is removed with the wire spring attached to the fan motor, the fan motor will not be installed in the reverse direction when reassembling the fan motor, and erroneous assembly can be prevented. .

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing a laser beam printer with a part of the exterior thereof removed as an embodiment of the image forming apparatus according to the present invention. FIG. 2 is a side sectional view of the laser beam printer. In FIG. 1, a rectangular outside air inlet 32 is opened in the direction of the sheet metal frame 31 constituting the left and right side walls of the apparatus main body 1a, as shown in FIG. A rectangular frame-shaped fan case 33 is attached to the sheet metal frame 31 so as to surround the periphery of the outside air introduction port 32, and a fan motor 34 is disposed at the center of the fan case 33. A cooling fan (not shown) is attached to the end of the output shaft.

  Next, the internal structure of the laser beam printer 1 will be described with reference to FIG. 2. The laser beam printer 1 includes a paper feeding unit 2 provided at the lower part of the apparatus main body 1 a and a device above the paper feeding unit 2. An image forming unit 3 provided at a substantially central portion in the main body 1 a, a fixing unit 4 disposed behind the image forming unit 3, and a discharge unit provided above the apparatus main body 1 a above the fixing unit 4. A paper unit 5 and a paper refeeding conveyance unit 6 for re-feeding the paper to the image forming unit 3 by reversing the front and back when forming images on both sides of the paper are provided.

  The paper feed unit 2 stores paper and feeds the paper toward the image forming unit 3. The paper feed unit 2 includes a paper feed cassette 7 and a manual feed tray 8. The paper feed unit 2 includes a pickup roller 10 that picks up the sheets stacked on the paper stacking plate 9 in the paper feed cassette 7 one by one, and a feed that feeds the picked up paper to the horizontal part L1 of the transport path L. In addition to the paper rollers 11 to 15 and the registration roller pair 16 that is supplied to the transfer unit of the image forming unit 3 at a predetermined timing after temporarily waiting the fed paper, the paper placed on the manual feed tray 8 is taken out. A pickup roller 17 is provided.

  The image forming unit 3 forms an image on a sheet supplied from the sheet feeding unit 2, and is an image carrier that is rotatably disposed at a substantially central portion in the front-rear direction of the horizontal portion L 1 of the transport path L. A photosensitive drum 18, a charger 19 disposed around the photosensitive drum 18, a developing device 20, a transfer roller 21 and a cleaning device 22, a laser scanner unit (LSU) 23 disposed above them, a toner hopper 24, and the like. .

  The fixing unit 4 is for fixing the toner image transferred to the sheet in the image forming unit 3 to the sheet, and includes a heating roller 25 and a pressure roller 26 that are pressed against each other and rotated. Yes.

  Further, the paper discharge unit 5 is for discharging the paper on which the toner image has been fixed in the fixing unit 4 to the outside of the apparatus main body 1a, and is provided in the middle of the vertical portion L2 of the transport path L. A pair of transport rollers 27, a pair of paper discharge rollers 28 provided at the end of the vertical portion L2, and a paper discharge tray 29 for stacking sheets discharged to the outside of the apparatus main body 1a.

  The re-feed conveyance unit 6 is used when images are formed on both sides of a sheet, and includes another conveyance path L ′ arranged below the horizontal portion L1 of the conveyance path L and its conveyance path L ′. A plurality of conveyance roller pairs 30 provided at appropriate positions are provided.

  Next, an image forming operation of the laser beam printer 1 having the above configuration will be described.

  For example, when a print start signal is transmitted to the laser beam printer 1 from a terminal such as a personal computer (personal computer), in the image forming unit 3, the photosensitive drum 18 is driven in the direction indicated by the arrow (clockwise) in FIG. ) And the surface thereof is uniformly charged to a predetermined potential by the charger 19. Then, when laser light based on image data transmitted from the terminal is output from the laser scanner unit 23 and irradiated onto the photosensitive drum 18, an electrostatic latent image is formed on the photosensitive drum 18. Then, the electrostatic latent image formed on the photosensitive drum 18 is developed by the developing device 20 using toner as a developer to be visualized as a toner image.

  At the same time, in the paper feed unit 2, for example, the sheets stored in the paper feed cassette 7 are picked up one by one from the uppermost one by the pickup roller 10, and are fed to the registration roller pair 16 by the plurality of paper feed rollers 11 to 15. First, the paper is fed first, and is temporarily put into a standby state by the registration roller pair 16. Thereafter, the registration roller pair 16 is rotationally driven at a predetermined timing synchronized with the toner image on the photosensitive drum 18, and the sheet is transferred to a transfer portion that is a contact portion between the photosensitive drum 18 and the transfer roller 21 of the image forming unit 3. The paper is fed secondary.

  In the image forming unit 3, the paper supplied from the registration roller pair 16 to the transfer unit between the photosensitive drum 18 and the transfer roller 21 by the secondary paper feeding is conveyed while being pressed against the photosensitive drum 18 by the transfer roller 21. As a result, the toner image on the photosensitive drum 18 is transferred to the surface (transfer surface). The sheet onto which the toner image has been transferred is conveyed to the fixing unit 4, and is heated and pressed in the process of being sandwiched and conveyed between the heating roller 25 and the pressure roller 26 in the fixing unit 4. Get fixed. The toner remaining on the surface of the photosensitive drum 18 (transfer residual toner) after the transfer of the toner image onto the paper is removed by the cleaning device 22.

  Thus, the sheet on which the toner image is fixed on the surface by the fixing unit 4 is conveyed upward through the vertical portion L2 of the conveyance path L by the conveyance roller pair 27, and the upper portion of the apparatus main body 1a by the discharge roller pair 28. The paper is discharged and stacked on a paper discharge tray 29 provided at the front.

  Next, the static elimination structure of the fan motor 34 constituting the gist of the present invention will be described with reference to FIGS.

  3 is a perspective view of the fan motor mounting portion of the apparatus main body, FIG. 4 is a perspective view of the fan case and the fan motor, and FIG. 5 is a perspective view of the fan case and the fan motor viewed from the inside of the apparatus main body (the back side in FIG. 4). FIG. 6 is a perspective view of a wire spring.

  In the present embodiment, a wire spring 35 for static elimination is wound around the motor fan 34, one end of the wire spring 35 is locked to the fan case 33, and the other end is locked to the sheet metal frame 31 which is a main body frame. It is a feature. Specifically, as shown in FIG. 6, a “no” -shaped portion 35 a having the same diameter as the outer diameter of the fan motor 34 is formed at the center of the wire spring 35, and the “no” -shaped portion. As shown in FIGS. 3 and 4, 35 a is fitted into the outer periphery of the motor fan 34 and fixed. Then, one end of the wire spring 35 is bent into a J-shape like a fishing hook to form a bent portion 35b, a tension spring portion 35c is formed at the other end, and a hook 35d is formed at the end of the tension spring portion 35c. Has been.

  Here, the size of the J-shaped bent portion 35b formed at one end of the wire spring 35 is larger than the inner diameter of the screw insertion holes 33a provided at the four corners of the fan case 33 shown in FIGS. The bent portion 35b is passed through one of the screw insertion holes 33a. At this time, the bent portion 35b of the wire spring 35 passes through the screw insertion hole 33a of the fan case 33 in order to elastically deform, and when it passes through the screw insertion hole 33a, it is restored to its original shape and size by elasticity. As shown in FIG. 5, the end portion is locked and fixed to the peripheral edge of the screw insertion hole 33 a of the fan case 33.

  The other end of the wire spring 35 is pulled to extend the tension spring portion 35c, and the hook 35d at the end is cut and raised on the sheet metal frame 31 as shown in FIG. It is fixed to the sheet metal frame 31 by being hooked and locked. It is not always necessary to form the tension spring portion 35 c on the wire spring 35, and the wire spring 35 may be hooked on the sheet metal frame 31 by the spring elasticity of the “-”-shaped portion 35 a in the center.

  Thus, while the laser beam printer 1 shown in FIG. 1 is operating, a cooling fan (not shown) is rotationally driven by the fan motor 34, and the outside air shown in FIG. It is introduced into the image forming apparatus main body 1a from the introduction port 32 and used for cooling.

  As described above, according to the present embodiment, the wire motor 35 for static elimination is wound around the fan motor 34, one end of the wire spring 35 is locked to the fan case 33, and the other end is locked to the sheet metal frame 31. Thus, the wire spring 35 can be easily assembled, and by this wire spring 35, the static electricity can be effectively removed from all angles, and the circuit connected to the fan motor 34 can be reliably protected from static electricity.

  In particular, in the present embodiment, the one end bent portion 35b of the wire spring 35 bent in a J-shape is passed through the screw insertion hole 33a of the fan case 33 and locked to the periphery of the screw insertion hole 33a. Can be easily assembled with one touch. Also, if the fan motor 34 is removed while the wire spring 35 is still attached to the fan motor 34, the fan motor 34 is not attached in the reverse direction when the fan motor 34 is reassembled, and erroneous assembly occurs. The effect that it can prevent is also acquired.

  In the above, the embodiment in which the present invention is applied to a laser beam printer has been described. However, the present invention is not limited to a printer, but to any other image forming apparatus such as a copying machine, a facsimile machine, or a multifunction machine thereof. Of course, the same applies.

It is a perspective view which removes and shows a part of exterior of the laser beam printer which concerns on this invention. 1 is a side sectional view of a laser beam printer according to the present invention. It is a perspective view of the fan motor attachment part of the apparatus main body of the laser beam printer which concerns on this invention. 1 is a perspective view of a fan case and a fan motor of a laser beam printer according to the present invention. FIG. 5 is a perspective view of the laser beam printer fan case and fan motor according to the present invention as seen from the inside of the apparatus main body (the back side in FIG. 4). It is a perspective view of a wire spring.

Explanation of symbols

1 Laser beam printer (image forming device)
DESCRIPTION OF SYMBOLS 1a Image forming apparatus main body 2 Paper feed part 3 Image formation part 4 Fixing part 5 Paper discharge part 6 Refeed conveyance part 7 Paper feed cassette 8 Manual feed tray 9 Paper stacking board 10 Pickup roller 11-15 Paper feed roller 16 Registration roller pair 17 Pickup Roller 18 Photosensitive Drum 19 Charger 20 Developing Device 21 Transfer Roller 22 Cleaning Device 23 Laser Scanner Unit (LSU)
24 toner hopper 25 heating roller 26 pressure roller 27 transport roller pair 28 paper discharge roller pair 29 paper discharge tray 30 transport roller pair 31 sheet metal frame (main body frame)
31a Locking piece of sheet metal frame 32 Outside air introduction port 33 Fan case 33a Screw insertion hole of fan case 34 Fan motor 35 Wire spring 35a "No" shape portion of wire spring 35b Wire spring bent portion 35c Wire spring tension spring Part 35d Wire spring hook L, L 'Transport path L1 Transport path horizontal section L2 Transport path vertical section

Claims (3)

In an image forming apparatus provided with a fan motor that rotationally drives a cooling fan,
An image forming apparatus, wherein a wire spring for static elimination is wound around the motor fan, one end of the wire spring is locked to a fan case, and the other end is locked to a main body frame.   A "" "-shaped part having substantially the same diameter as the outer diameter of the fan motor is formed at the center of the wire spring, and the" "" -shaped part is fitted on the outer periphery of the fan motor. The image forming apparatus according to claim 1. 3. The wire spring according to claim 1, wherein one end of the wire spring is bent in a J shape, and the bent portion is passed through a screw insertion hole formed in the fan case to be engaged with a periphery of the screw insertion hole of the fan case. The image forming apparatus described.

Images