JP2020112748A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that allows easy removal of a sheet.SOLUTION: An image forming apparatus 100 comprises: a housing 30; a pendulum unit 10; a support part 22B; a first rotating body 21; and a cover 31. The housing 30 has an opening 30A. The support part 22B supports the pendulum unit 10 for allowing a free pendulum motion. The cover 31 is attached to the housing 30 such that it can make a transition between a closing state to close the opening 30A and an opening state to open the opening 30A. The pendulum unit 10 has a second rotating body 11 and a wall part 12C. The housing 30, pendulum unit 10, support part 22B, first rotating body 21, and cover 31 are configured such that, when the cover 31 is in the closing state, the cover 31 presses the wall part 12C to bring the second rotating body 11 into pressure contact with the first rotating body 21, and when the cover 31 is in the opening state, the self weight of the pendulum unit 10 causes the second rotating body 11 and first rotating body 21 to separate from each other.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image forming apparatus.

The image forming apparatus disclosed in Patent Document 1 transfers a toner image to a transfer material and fixes the toner image on the transfer material. The image forming apparatus disclosed in Patent Document 1 has a fixing unit and a front door. The fixing unit includes a pressure roller and a heating roller that is in pressure contact with the pressure roller and is driven to rotate. The front door is provided on the main body of the image forming apparatus so as to be openable and closable. The pressure roller makes a transition in conjunction with the opening/closing operation of the front door. Specifically, when the front door is in the closed state, the pressure roller is in pressure contact with the heating roller. When the front door is open, the pressure contact of the pressure roller with the heating roller is released.

JP, 2007-33638, A

However, in the image forming apparatus disclosed in Patent Document 1, the pressure roller is in contact with the heating roller when the front door is in the open state. Therefore, the paper jammed between the pressure roller and the heating roller cannot be easily removed.

In view of the above problems, it is an object of the present invention to provide an image forming apparatus that can easily remove a sheet.

The image forming apparatus of the present invention forms an image on a sheet. The image forming apparatus includes a housing, a pendulum unit, a support section, a first rotating body, and a cover. The housing has an opening. The pendulum unit is disposed inside the housing and faces the opening. The support section supports the pendulum unit so that the pendulum can freely move. The first rotating body is disposed inside the housing and faces the pendulum unit. The cover is attached to the housing so as to be transitionable between a closed state in which the opening is closed and an open state in which the opening is opened. The pendulum unit has a second rotating body and a wall portion. The second rotating body conveys the paper together with the first rotating body. The wall portion abuts the cover in the closed state. When the cover is in the closed state, the cover pushes the wall portion to move the second rotary body to the first rotary body, the pendulum unit, the support portion, the first rotary body, and the first rotary body. When the cover is in the open state by being pressed against the rotating body, the second rotating body and the first rotating body are separated from each other by the weight of the pendulum unit.

According to the image forming apparatus of the present invention, the sheet can be easily removed.

FIG. 1 is a diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. (A) And (b) is a figure which shows the structure of the fixing device which concerns on embodiment of this invention. FIG. 1 is a diagram showing a configuration of a fixing device according to an exemplary embodiment of the present invention. (A) And (b) is a figure which shows the structure of the pendulum unit which concerns on embodiment of this invention.

An embodiment of an image forming apparatus according to the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference symbols and description thereof will not be repeated.

The configuration of the image forming apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing the configuration of an image forming apparatus 100 according to this embodiment.

The image forming apparatus 100 forms an image on the paper P. Specifically, the image forming apparatus 100 reads a document to generate image data, and prints a printed matter based on the image data.

As shown in FIG. 1, the image forming apparatus 100 includes a housing 30. The housing 30 has a substantially rectangular parallelepiped shape. The housing 30 has an opening 30A. In the following description of the present embodiment, the side where the opening 30A of the image forming apparatus 100 is arranged is the front side of the image forming apparatus 100 and the opposite side is the rear side of the image forming apparatus 100. The present embodiment will be described with the right side of the image forming apparatus 100 viewed from the front side as the right side of the image forming apparatus 100 and the opposite side as the left side of the image forming apparatus 100. Further, in a direction orthogonal to the front-rear direction and the left-right direction of the image forming apparatus 100, the side on which the image reading unit 40 described later is arranged is the upper side of the image forming apparatus 100, and the opposite side is the lower side of the image forming apparatus 100. This embodiment will be described.

The image forming apparatus 100 further includes a cover 31 and a rotating pin 32. The rotating pin 32 is provided on the lower portion of the cover 31. The cover 31 is attached to the housing 30 by a rotating pin 32 so as to be able to transition between a closed state and an open state. The closed state refers to a state in which the cover 31 closes the opening 30A of the housing 30. The open state indicates a state in which the cover 31 opens the opening 30A of the housing 30. That is, the open state indicates a state in which the cover 31 does not close the opening 30A of the housing 30. In this way, the cover 31 can rotate about the rotation pin 32. The cover 31 has a substantially rectangular shape when viewed from the front side. The cover 31 has a flat plate shape, and the first main surface 31A and the second main surface 31B of the cover 31 are flat surfaces. The first main surface 31A indicates an inner surface of the image forming apparatus 100. The 2nd main surface 31B shows the surface on the opposite side to the 1st main surface 31A of cover 31.

The image forming apparatus 100 includes an image reading unit 40, a conveyance unit 50, a paper feeding unit 60, and a printing unit 70. The housing 30 accommodates the image reading unit 40, the transport unit 50, the paper feeding unit 60, and the printing unit 70 inside.

The image reading unit 40 reads a document placed on a document table and generates image data. The image reading unit 40 is, for example, a scanner.

The transport unit 50 transports the paper P fed from the paper feed unit 60 so as to pass through the printing unit 70.

The sheet feeding unit 60 feeds the sheets P one by one to the conveying unit 50. The paper feeding unit 60 includes a paper feeding cassette 61 and a paper feeding roller group 62. The paper feed cassette 61 can accommodate a plurality of paper sheets P. The paper feed roller group 62 feeds the paper P stored in the paper feed cassette 61 to the transport unit 50 one by one.

The printing unit 70 forms an image on the paper P fed from the paper feeding unit 60. The printing unit 70 includes an exposure device 71, a developing device 72, a photosensitive drum 73, a transfer device 74, and a fixing device 75. The exposure device 71 irradiates the photoconductor drum 73 with laser light based on the image data. As a result, an electrostatic latent image is formed on the surface of the photoconductor drum 73. The developing device 72 supplies toner to the photosensitive drum 73 to develop the electrostatic latent image. As a result, a toner image is formed on the surface of the photosensitive drum 73. The transfer device 74 transfers the toner image formed on the surface of the photosensitive drum 73 onto the paper P. The sheet P is transported by the transport unit 50 toward the fixing device 75.

The fixing device 75 heats and presses the paper P on which the toner image is transferred. As a result, the toner image on the paper P is fixed on the paper P. As shown in FIG. 1, the fixing device 75 includes a pressure roller 11 and a heat roller 21. The pressure roller 11 and the heat roller 21 form a fixing roller pair. The heat roller 21 heats the paper P on which the toner image is transferred. The pressure roller 11 presses the paper P on which the toner image is transferred together with the heat roller 21. The pressure roller 11 and the heat roller 21 are arranged to face each other. In this embodiment, the pressure roller 11 and the heat roller 21 face each other in the front-rear direction. The pressure roller 11 and the heat roller 21 both convey the paper P in the vertical direction. The pressure roller 11 is an example of a second rotating body. The heat roller 21 is an example of a first rotating body. Details of the configuration of the fixing device 75 will be described later with reference to FIGS.

The image forming apparatus 100 further includes a control unit. The control unit includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control unit controls the operation of each unit of the image forming apparatus 100 by executing the control program stored in the ROM.

Next, with reference to FIGS. 2A to 4B, the configuration of the fixing device 75 will be further described. 2A, 2B, and 3 are diagrams showing the configuration of the fixing device 75 according to the present embodiment. Specifically, FIG. 2A is a side view showing the fixing device 75 in the first state. The fixing device 75 is in the first state when the cover 31 is in the closed state. FIG. 2B is a side view showing the fixing device 75 in the second state. The fixing device 75 is in the second state when the cover 31 is in the open state. FIG. 3 is a top view showing the fixing device 75 in the first state.

As shown in FIG. 1, FIG. 2A, FIG. 2B, and FIG. 3, the fixing device 75 is arranged inside the housing 30 in the vicinity of the opening 30A.

As shown in FIGS. 1, 2A, 2B, and 3, the fixing device 75 includes a pendulum unit 10 and a fixing unit 20. The fixed unit 20 is fixed inside the image forming apparatus 100. The pendulum unit 10 is supported by the fixed unit 20. The pendulum unit 10 faces the opening 30A. The heat roller 21 faces the pendulum unit 10.

Next, the pendulum unit 10 will be described with reference to FIGS. 2(a) to 4(b). FIG. 4A and FIG. 4B are diagrams showing the configuration of the pendulum unit 10 according to the present embodiment. Specifically, FIG. 4A is a perspective view showing a part of the members constituting the pendulum unit 10. FIG. 4B is a perspective view showing the pendulum unit 10.

As shown in FIGS. 2A to 4B, the pendulum unit 10 includes a pressure roller 11, a support frame 12, a support shaft 13, a coil spring 14, and a bearing member 15. The pressure roller 11 is rotatably supported by the bearing member 15. The support shaft 13, the coil spring 14, and the bearing member 15 are mounted on the support frame 12, respectively. The coil spring 14 is an example of a biasing member.

The pressure roller 11 has a first shaft portion 111 and a first roller portion 112. The first roller portion 112 has a tubular shape. The first roller portion 112 accommodates a part of the first shaft portion 111. The first roller portion 112 includes an elastic member. When the cover 31 is in the closed state, the pressure roller 11 is driven to rotate according to the rotation of the heat roller 21.

The support frame 12 has a substantially U-shape when viewed from the front-rear direction in FIGS. 2A to 4B. The support frame 12 has a base portion 12A, a pair of side portions 12B, and a wall portion 12C (see FIG. 3). The base portion 12A has a plate shape. The longitudinal direction of the base portion 12A is the left-right direction. The lateral direction of the base portion 12A is the front-back direction. The pair of side portions 12B are provided at both ends of the base portion 12A in the longitudinal direction (horizontal direction). The wall portion 12C is provided at an end portion of the base portion 12A on the cover 31 side in the lateral direction (front-back direction). The wall portion 12C is provided along the longitudinal direction (horizontal direction) of the base portion 12A.

As shown in FIGS. 4A and 4B, the side portion 12B has a plate shape. The side portion 12B has a cutout portion 12B1 and a first through hole 12B2.

The coil spring 14 and the bearing member 15 are attached to the cutout portion 12B1. As shown in FIG. 4A, the cutout portion 12B1 has a pair of side edge portions 12B11, a rear edge portion 12B12, and a protruding portion 12B13. The pair of side edge portions 12B11 regulates the moving direction of the bearing member 15. As shown in FIG. 4A, the protrusion 12B13 is located at the center of the back edge 12B12 in the vertical direction. The protruding portion 12B13 projects rearward from the inner edge portion 12B12. As shown in FIG. 4B, one end of the coil spring 14 is inserted into the protrusion 12B13.

The first through hole 12B2 supports the support shaft 13. The first through hole 12B2 has a substantially circular shape when viewed in the left-right direction. The support shaft 13 has a substantially circular cross section.

The wall portion 12C has a plate shape. As shown in FIGS. 2A and 3, when the cover 31 is in the closed state, the wall portion 12C contacts the first main surface 31A of the cover 31. The surface of the wall portion 12C on the cover 31 side is a flat surface like the first main surface 31A of the cover 31.

When the cover 31 is in the closed state, the coil spring 14 urges the pressure roller 11 so as to press the heat roller 21. Specifically, the coil spring 14 biases the pressure roller 11 in the rearward direction when the cover 31 is in the closed state. In other words, the coil spring 14 biases the pressure roller 11 so that a desired pressing force is applied between the pressure roller 11 and the heat roller 21 while the image forming apparatus 100 is forming an image on the sheet P. .. As shown in FIG. 4B, the coil spring 14 is arranged between the support frame 12 and the bearing member 15. One end of the coil spring 14 is attached to the protrusion 12B13 of the support frame 12. The other end of the coil spring 14 is attached to a later-described spring seat 15C of the bearing member 15.

The bearing member 15 is attached to the cutout portion 12B1 so as to be transitionable along the pair of side edge portions 12B11. Therefore, the bearing member 15 enables the pressure roller 11 to transition. The bearing member 15 has a substantially flat plate shape. As shown in FIG. 4A, the bearing member 15 has a second through hole 15A, a guide groove 15B, and a spring seat 15C. The second through hole 15A supports the pressure roller 11. The first shaft portion 111 of the pressure roller 11 is inserted into the second through hole 15A. As shown in FIG. 4A, the guide grooves 15B are provided at both end portions of the bearing member 15 in the vertical direction. The groove width of the guide groove 15B is such that the side edge portion 12B11 of the support frame 12 can be inserted and the bearing member 15 can transition. The spring seat 15C is inserted into the other end of the coil spring 14.

Next, the fixed unit 20 will be described with reference to FIGS. The fixed unit 20 has a heat roller 21 and a housing 22. The heat roller 21 is rotatably attached to the housing 22.

The heat roller 21 has a second shaft portion 211, a second roller portion 212, and a heat source. The second shaft portion 211 is provided at both ends of the second roller portion 212 in the longitudinal direction (horizontal direction) (see FIG. 3 ). The 2nd roller part 212 contains metal, for example. The heat source sets the outer peripheral temperature of the second roller portion 212 to a fixing temperature at which fixing processing can be performed. The heat source is housed inside the second roller portion 212. The heat source includes, for example, a halogen heater or a ceramic heater. The heat roller 21 further includes a transmission gear unit. The image forming apparatus 100 further includes a drive source. The transmission gear unit transmits the power of the drive source to the heat roller 21. As a result, the heat roller 21 is rotationally driven by the power of the drive source. The drive source is, for example, a motor.

The housing 22 houses the heat roller 21. The housing 22 has a main body 22A and a support 22B. The main body 22A houses the heat roller 21. The support portion 22B supports the pendulum unit 10 so that the pendulum can freely move in the front-rear direction. The support portion 22B is located above the housing 22 and protrudes from the main body portion 22A toward the cover 31. The support portion 22B has a support groove 22B1. When the cover 31 is in the closed state, the support groove 22B1 is located on the front side of the position of the first shaft portion 111 of the pressure roller 11. The support groove 22B1 rotatably supports the support shaft 13 of the pendulum unit 10. As shown in FIGS. 2A and 2B, the shape of the support groove 22B1 is a substantially U-shape in a side view.

In this way, the support groove 22B1 of the fixed unit 20 supports the support shaft 13 of the pendulum unit 10, so that the pendulum unit 10 can move the pendulum with respect to the fixed unit 20 about the support shaft 13 as a fulcrum.

Further, the weight of the pressure roller 11 is the largest among the constituent members constituting the pendulum unit 10. In other words, the center of gravity of the pendulum unit 10 is on the first shaft portion 111. Therefore, when no external force acts on the pendulum unit 10, the straight line XX (FIG. 2B) connecting the support shaft 13 and the first shaft portion 111 is parallel to the vertical direction. The pressure roller 11 and the heat roller 21 are configured such that the first roller portion 112 and the second roller portion 212 are separated from each other in a state where no external force acts on the pendulum unit 10.

As shown in FIG. 2A, when the cover 31 is in the closed state, the cover 31 presses the wall portion 12C to bring the pressure roller 11 into pressure contact with the heat roller 21. At this time, as shown in FIG. 2A, the biasing force of the coil spring 14 opposes the external force F in the forward direction applied to the pressure roller 11 in response to the contact of the pressure roller 11 with the heat roller 21. ing. Further, the paper P sandwiched between the heat roller 21 and the pressure roller 11 is conveyed in a direction substantially parallel to the vertical direction.

As shown in FIG. 2B, when the cover 31 is in the open state, the cover 31 is released from the pressure from the wall portion 12C. As a result, the pressure roller 11 and the heat roller 21 are separated from each other by the weight of the pendulum unit 10. At this time, as shown in FIG. 2B, the coil spring 14 is in a fully extended state.

As described above with reference to FIGS. 1 to 4B, in the present embodiment, the housing 31, the pendulum unit 10, the support portion 22B, the heat roller 21, and the cover 31 have the cover 31 in the closed state. In such a case, the cover 31 is configured to press the wall portion 12</b>C to bring the pressure roller 11 into pressure contact with the heat roller 21. Further, in the case 30, the pendulum unit 10, the support portion 22B, the heat roller 21, and the cover 31, when the cover 31 is in the open state, the pressure roller 11 and the heat roller 21 are separated from each other by the weight of the pendulum unit 10. Is configured. Therefore, when a paper jam (jam) occurs between the pressure roller 11 and the heat roller 21 while the image forming apparatus 100 is forming an image on the paper P, the cover 31 is simply opened. The pressure roller 11 and the heat roller 21 can be separated. That is, the pressing of the pressure roller 11 against the heat roller 21 is released at the same time when the cover 31 is opened. As a result, the user can easily remove the paper P jammed between the pressure roller 11 and the heat roller 21.

In the present embodiment, the weight of the pressure roller 11 is the largest among the constituent members of the pendulum unit 10. As a result, when the cover 31 is in the open state, the pressure roller 11 is reliably separated from the heat roller 21.

In the present embodiment, the pendulum unit 10 has a coil spring 14. Thereby, when the cover 31 is in the closed state, the pressure roller 11 surely contacts the heat roller 21. Further, the pendulum unit 10 can adjust the pressing force of the pressure roller 11 against the heat roller 21 by including the coil spring 14.

The embodiments of the present invention have been described above with reference to the drawings (FIGS. 1 to 4B). However, the present invention is not limited to the above-described embodiment, and can be carried out in various modes within the scope of the invention (for example, (1) to (10) shown below). For easy understanding, the drawings mainly show the respective constituent elements, and the thickness, length, number, etc. of the respective constituent elements shown in the drawings are different from the actual ones for the convenience of drawing the drawing. .. Further, the materials, shapes, dimensions, etc. of the respective constituent elements shown in the above-described embodiment are merely examples, and are not particularly limited, and various changes can be made without departing substantially from the effects of the present invention. is there.

(1) As described with reference to FIGS. 1 to 4B, in the embodiment of the present invention, the heat roller 21 is used as the first rotating body, but the present invention is not limited to this. For example, the first rotating body may be a rotating member such as a fixing belt.

(2) As described with reference to FIGS. 1 to 4B, in the embodiment of the present invention, the weight of the pressure roller 11 is the largest among the constituent members of the pendulum unit 10. However, the present invention is not limited to this. For example, the weight of the pressure roller 11 does not have to be the largest among the constituent members of the pendulum unit 10.

(3) As described with reference to FIGS. 1 to 4B, in the embodiment of the present invention, the first roller and the second roller are a pair of fixing rollers, but the present invention is not limited to this. For example, the first roller and the second roller may be a pair of transport rollers that sandwich and transport the paper P. When the first roller and the second roller are a pair of transport rollers, the sheet P jammed between the pair of transport rollers can be easily removed.

(4) As described with reference to FIGS. 1 to 4B, in the embodiment of the present invention, the heat roller 21 is used as the first roller and the pressure roller 11 is used as the second roller. The invention is not limited to this. For example, the pressure roller 11 may be used as the first roller and the heat roller 21 may be used as the second roller.

(5) As described with reference to FIGS. 1 to 4B, in the embodiment of the present invention, the pendulum unit 10 has the coil spring 14, but the present invention is not limited to this. For example, the pendulum unit 10 may not have the coil spring 14. Further, in the embodiment of the present invention, the coil spring 14 is used as the biasing member, but the present invention is not limited to this. For example, the biasing member includes a metal plate spring and a torsion spring.

(6) As described with reference to FIGS. 1 to 4B, in the embodiment of the present invention, the fixing device 75 has the housing 22, but the present invention is not limited to this. For example, the fixing device 75 may not include the housing 22. Further, in the embodiment of the present invention, the housing 22 has the support portion 22B, but the present invention is not limited to this. For example, the housing 22 may not have the support portion 22B.

(7) As described with reference to FIGS. 1 to 4B, in the embodiment of the present invention, when the cover 31 is in the closed state, the cover 31 is sandwiched between the heat roller 21 and the pressure roller 11. The housing 30, the pendulum unit 10, the support portion 22B, the heat roller 21, and the cover 31 are configured so that the paper P is conveyed in a direction substantially parallel to the gravity direction, but the present invention is not limited to this. .. For example, the housing 30, the pendulum unit 10, the support portion 22B, and the heat roller so that the paper P sandwiched between the heat roller 21 and the pressure roller 11 is conveyed in a direction that is not substantially parallel to the gravity direction. 21 and the cover 31 may be configured.

(8) As described with reference to FIGS. 1 to 4B, in the fixing device 75 in the embodiment of the present invention, the support groove 22B1 of the fixed unit 20 supports the support shaft 13 of the pendulum unit 10. However, the present invention is not limited to this. For example, the fixing unit 20 has the support shaft 13, the pendulum unit 10 has a hook groove, and the support shaft 13 of the fixed unit 20 supports the hook groove of the pendulum unit 10 to form the fixing device 75. Good.

(9) As described with reference to FIGS. 1 to 4B, in the embodiment of the present invention, the surface of the wall portion 12C on the cover 31 side is a flat surface, but the present invention is not limited to this. The surface of the wall portion 12C on the cover 31 side may have a shape that comes into contact with the first main surface 31A of the cover 31 when the cover 31 is in the closed state.

(10) As described with reference to FIGS. 1 to 4B, in the embodiment of the present invention, the housing 22 has the support portion 22B, but the present invention is not limited to this. For example, the housing 30 may have the support portion 22B.

The present invention is useful, for example, in the field of image forming apparatuses.

100 Image forming apparatus 10 Pendulum unit 11 Pressure roller 12C Wall part 21 Heat roller 22B Support part 30 Housing 30A Opening 31 Cover P Paper 2 Information processing device 3 Image forming device 21 Communication part 23 Control part

Claims (7)

An image forming apparatus for forming an image on a sheet,
A housing having an opening,
A pendulum unit disposed inside the housing and facing the opening,
A support portion that supports the pendulum unit so that the pendulum can freely move,
A first rotating body which is arranged inside the housing and faces the pendulum unit;
A cover attached to the housing so as to be able to transition between a closed state in which the opening is closed and an open state in which the opening is opened,
The pendulum unit is
A second rotating body that conveys the paper together with the first rotating body;
A wall portion with which the cover in the closed state abuts,
When the cover is in the closed state, the cover pushes the wall portion to move the second rotating body to the first rotating body, the pendulum unit, the supporting portion, the first rotating body, and the first rotating body. The image forming apparatus is configured such that when the cover is brought into pressure contact with a rotating body and the cover is in the open state, the second rotating body and the first rotating body are separated from each other by the weight of the pendulum unit. The image forming apparatus according to claim 1, wherein the weight of the second rotating body is the largest among the constituent members that configure the pendulum unit. The first rotating body is a first roller, the second rotating body is a second roller,
The image forming apparatus according to claim 1, wherein the first roller and the second roller form a fixing roller pair. The first roller is a heat roller,
The image forming apparatus according to claim 3, wherein the second roller is a pressure roller. The pendulum unit includes a biasing member that biases the second rotary body such that the second rotary body presses against the first rotary body when the cover is in the closed state. The image forming apparatus according to claim 4. A housing for accommodating the first rotating body,
The housing has the support portion,
The image forming apparatus according to claim 1, wherein the support portion projects toward the cover. When the cover is in the closed state, the housing sandwiched between the first rotating body and the second rotating body is conveyed in a direction substantially parallel to the direction of gravity so that the sheet is conveyed. The image forming apparatus according to claim 1, wherein the pendulum unit, the supporting portion, the first rotating body, and the cover are configured.

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