JP6149631B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including a paper feed unit having a paper dust removing roller and a registration roller.

  2. Description of the Related Art As an image forming apparatus such as a laser printer or a digital copying machine, an image forming apparatus including a paper feeding unit having a structure in which a paper dust removing roller and a registration roller are supported by a frame is generally known.

  As a paper feeding unit of this type of image forming apparatus, for example, in FIGS. 4 and 6 of Patent Document 1, a pinch roller corresponding to a paper dust removing roller and a registration roller 16B facing the pinch roller support a frame unit. A paper feed unit having a structure supported by a frame is described.

  Here, the paper feeding unit is configured to be mounted between the left and right main body frames of the image forming apparatus. The pinch roller is connected to the ground path on the left side of the main body frame via a metal conveyance chute fixed to the support frame in order to remove the static electricity charged on the pinch roller and registration roller equivalent to the paper dust removal roller. The registration roller is connected to the ground path on the right side of the main body frame.

JP 2010-222107 A

  By the way, in the image forming apparatus described in Patent Document 1, when mounting the paper feeding unit between the left and right main body frames, for example, the paper feeding unit is slid toward the left main body frame, and this state is set as a positioning jig. Since the sheet feeding unit is mounted between the left and right body frames, the positioning jig is indispensable.

  Further, in the image forming apparatus described in Patent Document 1, a structure in which a pinch roller and a registration roller corresponding to a paper dust removing roller are connected to ground requires ground paths on the left and right of the main body frame, and the ground path is complicated. It was converted.

  Therefore, the present invention can eliminate the need for a positioning jig for mounting the support frame for supporting the paper dust removing roller and the registration roller on the main body frame, and can simplify the ground path of the paper dust removing roller and the registration roller. It is an object to provide an image forming apparatus.

  An image forming apparatus according to the present invention for solving the above-described problems is arranged between a first frame, a second frame facing the first frame, and between the first frame and the second frame. A third frame positioned with respect to the sheet, a paper dust removing roller supported by the third frame, a registration roller supported by the third frame and facing the paper dust removing roller, and the paper dust removing roller. A first wire; a second wire that is electrically connected to the registration roller and the first wire; and a biasing member for positioning that biases the third frame toward the first frame. The positioning biasing member is in contact with at least one of the first wire and the second wire, and is electrically connected to the ground member provided in the second frame.

  In this image forming apparatus, the third frame that supports the paper dust removing roller and the registration roller is disposed between the first frame and the second frame, and the third frame is directed toward the first frame by the positioning biasing member. Is positioned by being biased. Here, the positioning biasing member is not a simple positioning member like a conventional positioning jig, but a member that is connected to the grounding member to form the grounding path, so the number of parts is reduced by sharing the member. It becomes possible to do.

  Further, the positioning biasing member contacts at least one of the first wire that is conducted to the paper dust removing roller and the second wire that is conducted to the registration roller and the first wire. Since it is electrically connected to the ground member provided in the two frames, the ground path of the paper dust removing roller and the registration roller is simplified.

  In the image forming apparatus described above, when the first wire and the second wire are pressed by the positioning biasing member, the first wire and the second wire are respectively conducted to the ground member via the positioning biasing member. The paper dust removing roller and the registration roller are electrically connected to the ground member.

  Further, when the overlapping portion of the first wire and the second wire is pressed by the positioning biasing member, the first wire and the second wire can be favorably conducted by the biasing force of the positioning biasing member. it can.

  Here, the first frame and the second frame facing each other with the third frame interposed therebetween can be reduced in weight by being made of resin.

  The second frame facing the first frame can be reinforced with a sheet metal as a ground member.

  According to the image forming apparatus of the present invention, the third frame that supports the paper dust removing roller and the registration roller is disposed between the first frame and the second frame, and the third frame is formed by the positioning biasing member. Since positioning is performed by being urged toward the first frame, a positioning jig conventionally required for mounting the third frame on the main body frame composed of the first frame and the second frame is unnecessary. be able to.

Further, the positioning biasing member contacts at least one of the first wire that is conducted to the paper dust removing roller and the second wire that is conducted to the registration roller and the first wire. Since it is electrically connected to the ground member provided in the two frames, the ground path of the paper dust removing roller and the registration roller can be simplified.

1 is a side sectional view showing a schematic configuration of a color printer as an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing an overview of a paper feeding unit in which a paper dust removing roller and a registration roller of the paper feeding unit shown in FIG. FIG. 3 is a rear view showing a state in which the paper feeding frame shown in FIG. FIG. 4 is a partially enlarged perspective view of FIG. 3 showing a contact state between a positioning biasing member and a sheet metal earth member. FIG. 3 is a partially enlarged perspective view of FIG. 2 showing a contact state between a positioning biasing member and a first wire and a second wire. It is a front view which shows typically the contact state of the biasing member for positioning, and the 1st wire and the 2nd wire, (a) shows the state where the 1st wire and the 2nd wire crossed, and (b) A state in which the first wire and the second wire do not intersect is shown.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of an image forming apparatus according to the invention will be described in detail with reference to the drawings as appropriate. An image forming apparatus according to an embodiment is embodied as a color printer 1 as illustrated in FIG. 1, for example. In the following description, the side facing the user who uses the color printer 1, that is, the left side of the sheet of FIG. 1 is “front”, the right side is “rear”, the vertical direction is “up / down”, and the front side is “ “Right” and the back side “Left”.

<Schematic configuration of color printer>
As shown in FIG. 1, the color printer 1 includes a paper feeding unit 20 disposed at the lower part in the main body frame 10, an image forming unit 30 disposed at the upper part in the main body frame 10, and a rear part in the main body frame 10. The fixing unit 80 and the paper discharge unit 90 are mainly provided. An upper cover 12 is provided on the upper side of the main body frame 10 so as to be openable and closable with the rear side as a rotation center.

  The paper feeding unit 20 includes a paper tray 21 that accommodates the paper S, a paper pressing plate 22 that biases the paper S upward, and a paper feed roller 23 that feeds the paper S biased upward by frictional contact forward. , A separation roller 24 and a separation pad 25 for separating the fed sheets S one by one. Further, on the downstream side of the paper feeding unit 20, there are a conveyance roller 26, a pinch roller 27, a paper dust removing roller 28, and a registration roller 29 as a conveyance unit for reversing and conveying the paper S from the upper side to the rear side. Has been placed.

  In the paper feed unit 20, the paper S stored in the paper tray 21 is fed forward as the paper feed roller 23 rotates and separated one by one by the separation roller 24 and the separation pad 25. Then, the sheet S is conveyed upward by the conveying roller 26 and the pinch roller 27 of the conveying unit, and conveyed to the rear image forming unit 30 side by the paper dust removing roller 28 and the registration roller 29.

  In the process of transporting the paper S by the transport unit, the paper dust removing rollers 27 and 28 absorb and collect the paper powder adhering to the paper S due to static electricity due to frictional charging. Further, the registration roller 29 corrects the skew of the sheet S conveyed to the image forming unit 30 side.

  The image forming unit 30 mainly includes four LED units 40, four process cartridges 50, and a transfer unit 70. Each process cartridge 50 includes a photoconductor cartridge 51 and a developing cartridge 61 that is detachably attached to the photoconductor cartridge 51.

  The LED unit 40 is disposed above the photosensitive drum 53 and includes a plurality of LEDs (light emitting diodes) (not shown) arranged in the left-right direction at the lower end thereof. The LED unit 40 exposes the surface of the photosensitive drum 53 by blinking the LED based on the image data. The LED unit 40 is held by the upper cover 12 and is separated from the photosensitive drum 53 by opening the upper cover 12.

  A plurality of process cartridges 50 are arranged side by side in the front-rear direction between the upper cover 12 and the paper feed tray 21, and are exchangeably mounted on the main body frame 10 in a state where the upper cover 12 is opened. It is the composition which becomes.

  Each photoconductor cartridge 51 mainly includes a photoconductor drum 53, a charger 54, and a collection roller 55. The collection roller 55 is a roller for collecting the transfer residual toner attached on the photosensitive drum 53.

  Each of the developing cartridges 61 includes a developing roller 63, a supply roller 64, a layer thickness regulating blade 65, an agitator 66, and an accommodating portion 67 that accommodates a positively chargeable toner as an example of a developer. It is comprised.

  The transfer unit 70 is provided between the paper feed tray 21 and the process cartridge 50, and mainly includes a driving roller 71, a driven roller 72, an endless conveyance belt 73, and four transfer rollers 74. ing. The conveying belt 73 is stretched between the driving roller 71 and the driven roller 72 so that the outer surface faces each of the arranged photosensitive drums 53. Each transfer roller 74 is arranged inside the conveyor belt 73 so as to sandwich the conveyor belt 73 between the photosensitive drums 53.

  The fixing unit 80 is provided behind the four process cartridges 50 of the image forming unit 30. The fixing unit 80 includes a heating roller 81 for heating the paper S and a pressure roller 82 for pressing the paper S between the heating roller 81. The heating roller 81 and the pressure roller 82 are rotatably supported by the fixing unit frame 83.

  The paper discharge unit 90 is provided continuously behind the fixing unit 80. The paper discharge unit 90 includes a conveyance roller 93 for conveying at least the paper S conveyed from the fixing unit 80 to the discharge port 92 along the paper discharge path 91, and the paper S from the discharge port 92 onto the paper discharge tray 13. A discharge roller 94 for discharging the paper is rotatably supported on the paper discharge unit frame 95.

  In the image forming unit 30, the surface of the photosensitive drum 53 is uniformly positively charged by the charger 54 and then exposed by the LED unit 40, whereby the electrostatic latent image based on the image data is formed on the photosensitive drum 53. Is formed. Further, the toner in the container 67 is supplied to the developing roller 63 to which the developing bias is applied via the supply roller 64 while being agitated by the agitator 66, and enters between the developing roller 63 and the layer thickness regulating blade 65. Then, it is carried on the developing roller 63 as a thin layer having a constant thickness. When the developing roller 63 comes into contact with the photosensitive drum 53, toner is supplied from the developing roller 63 to the photosensitive drum 53, whereby the electrostatic latent image is visualized and developed on the photosensitive drum 53. A toner image as an agent image is formed.

  Thereafter, the sheet S supplied to the image forming unit 30 is conveyed between the photosensitive drum 53 and the conveying belt 73, so that the toner image formed on the photosensitive drum 53 is transferred onto the sheet S. . The sheet S to which the toner image has been transferred is conveyed to the fixing unit 80, and the toner image is thermally fixed while passing between the heating roller 81 and the pressure roller 82, whereby an image is formed on the sheet S. The The sheet S on which the image is formed is transported along the paper discharge path 91 by the transport roller 93 and the discharge roller 94, passes through the discharge port 92 of the paper discharge unit frame 95, and is discharged from the main body frame 10. 13 is discharged.

<Detailed structure of paper feed unit>
As shown in FIG. 2, the paper dust removing roller 28 and the registration roller 29 are opposed to each other between the left frame portion 101A and the right frame portion 101B of the transport unit frame 101 constituting the transport unit unit 100. It is rotatably supported between them.

  As shown in FIG. 3, the transport unit frame 101 of the transport unit 100 is mounted between the left main body frame 10 </ b> A constituting the left and right walls of the main body frame 10 and the right main body frame. The left main body frame 10A and the right main body frame 10B are made of an insulating synthetic resin. Here, the left main body frame 10A corresponds to the first frame in the present invention, the right main body frame 10B corresponds to the second frame in the present invention, and the transport unit frame 101 corresponds to the third frame in the present invention.

  The conveying frame 101 that is the third frame has a left frame portion 101A that is formed by sandwiching a positioning biasing member 102 that is a compression coil spring between the right frame portion 101B and the right body frame 10B that is the second frame. Is mounted in a state of being pressed against the left main body frame 10A, which is the first frame.

  The positioning biasing member 102 is specifically a compression coil spring, and is made of a conductive metal material so as to function as a constituent member of the ground path. As shown in FIGS. 4 and 5, the positioning urging member 102 is accommodated in an accommodation groove 101 </ b> C formed at the right end portion of the right frame portion 101 </ b> B of the transport portion frame 101. The housing groove 101C is a groove that opens upward and extends in the left-right direction, and has a right end opened at a right end of the right frame portion 101B.

  In the free state, the positioning biasing member 102 has a right end protruding outward from the right end opening of the receiving groove 101C as shown in FIG. In the state in which the conveying unit frame 101 is mounted between the left main frame 10A and the right main frame 10B of the main body frame 10, the right end of the positioning biasing member 102 is made of sheet metal as shown in FIG. The ground member 103 is pressed to conduct.

  The sheet metal earth member 103 is provided on the right body frame 10B shown in FIG. 3, and reinforces the right body frame 10B.

  Here, as shown in an enlarged view in FIG. 5, the paper dust removing roller 28 and the registration roller 29 are connected to the sheet metal ground member 103 shown in FIG. A first wire 104 and a second wire 105 made of conductive metal are disposed.

  The first wire 104 is a wire for electrically connecting the paper dust removing roller 28 to the sheet metal grounding member 103 shown in FIG. 4, and the second wire 105 is the sheet metal grounding member shown in FIG. 103 is a wire for conducting to 103.

  One end of the first wire 104 is locked to the hook-shaped holding portion 101D, and the other end is sandwiched between the left end of the positioning biasing member 102 and the back of the receiving groove 101C for positioning. The biasing member 102 is electrically connected.

  The hook-shaped holding portion 101D is formed integrally with a conductive bearing 101E made of a conductive resin that supports the right end of the paper dust removing roller 28. A third wire 106 made of a conductive metal is wound around the conductive bearing 101E. One end of the third wire 106 is engaged with the hook-shaped holding portion 101D and is electrically connected to one end of the first wire 104 in a pressure contact state. Has been.

  The second wire 105 is wound in a coil spring shape with one end pressed against one end of the coiled earth member 107 and having the other end gradually expanded in diameter.

  The coiled ground member 107 is formed by winding a conductive metal material in a compression coil spring shape, and the other end is pressed against a conductive metal bearing (not shown) that pivotally supports the right end of the registration roller 29. doing.

  Here, in the vicinity of the other end portion of the first wire 104, a conducting portion 104 </ b> A that contacts the intermediate portion of the second wire 105 is formed. The conduction portion 104A of the first wire 104 overlaps with the intermediate portion of the second wire 105 when viewed from the left-right direction, and is pressed against the intermediate portion of the second wire 105 by receiving the urging force of the positioning urging member 102. ing.

<Effects of paper feeding unit>
In the color printer 1 that is the image forming apparatus of the present embodiment, the transport unit frame 101 of the transport unit 100 disposed between the left main body frame 10A and the right main body frame 10B is moved by the positioning biasing member 102 to the left main body. It is positioned by being urged toward the frame 10A.

  Therefore, in the color printer 1 of the present embodiment, a positioning jig that is conventionally required for mounting the transport unit frame 101 on the left main body frame 10A and the right main body frame 10B is not necessary. Here, the positioning biasing member 102 is not a simple positioning member such as a conventional positioning jig, but is a member that is electrically connected to the ground member to form a ground path. The number of parts can be reduced by sharing the members.

  Here, the ground path of the paper dust removing roller 28 is the conductive bearing 101E, the third wire 106, the first wire 104, the positioning biasing member 102, and the sheet metal grounding member 103 at the right end of the conveying unit frame 101. Consists of. Further, the ground path of the registration roller 29 is a conductive metal bearing (not shown), a coiled ground member 107, a second wire 105, a positioning biasing member 102, and a sheet metal ground at the right end of the transport unit frame 101. The member 103 is used.

  As described above, in the color printer 1 of the present embodiment, the ground path of the paper dust removing roller 28 and the ground path of the registration roller 29 are simply configured at the right end of the transport unit frame 101. Then, the first wire 104 and the second wire 105 are respectively conducted to the sheet metal grounding member 103 via the positioning biasing member 102, so that the paper dust removing roller 28 and the registration roller 29 are connected to the sheet metal grounding member 103. Good conduction.

  According to the color printer 1 of the present embodiment, the paper feed frame (third frame) 101 of the transport unit 100 that supports the paper dust removing roller 28 and the registration roller 29 is the left main body frame (first frame) of the main body frame 10. 10A and the right main body frame (second frame) 10B, and this paper feed frame (third frame) 101 is biased toward the left main body frame (first frame) 10A by the positioning biasing member 102. Thus, the positioning jig that has been conventionally required for mounting the transport unit frame 101 on the main body frame 10 can be eliminated.

  In addition, the ground path of the paper dust removing roller 28 and the ground path of the registration roller 29 can be simply configured at the end of the transport unit frame 101. The first wire 104 and the second wire 105 are electrically connected to the sheet metal grounding member 103 through the positioning biasing member 102, respectively, so that the paper dust removing roller 28 and the registration roller 29 are good for the sheet metal grounding member 103. Can be conducted.

  Further, since the left main body frame 10A and the right main body frame 10B of the main body frame 10 are made of resin, the weight can be reduced. Further, the right main body frame 10B can be reinforced by a sheet metal earth member 103.

  Here, in the color printer 1 of the present embodiment, the structure in which the first wire 104 and the second wire 105 are electrically connected to the end of the positioning biasing member 102 is, for example, as shown in FIG. The first wire 104 and the second wire 105 may be crossed and the periphery of the crossing and overlapping portion may be pressed by the end of the positioning biasing member 102. Further, for example, as shown in FIG. 6B, the first wire 104 and the second wire 105 may be placed substantially parallel and pressed by the end portion of the positioning biasing member 102.

  The color printer 1 according to the embodiment of the image forming apparatus according to the present invention has been described above. However, the image forming apparatus according to the present invention is not limited to the color printer 1 according to the embodiment. The positioning biasing member 102 can be changed to a leaf spring or a torsion spring.

  Further, the image forming apparatus of the present invention can be applied to a monochrome printer, a copying machine, a multifunction machine, and the like.

1 Color printer S Paper 10 Body frame 10A Left body frame (first frame)
10B Right body frame (second frame)
DESCRIPTION OF SYMBOLS 20 Paper feed part 28 Paper dust removal roller 29 Registration roller 30 Image formation part 80 Fixing part 90 Paper discharge part 100 Conveyance part unit 101 Conveyance part frame (3rd frame)
101A Left frame portion 101B Right frame portion 101C Housing groove 101D Holding portion 101E Conductive bearing 102 Positioning biasing member 103 Sheet metal ground member 104 First wire 105 Second wire 106 Third wire 107 Coiled ground member 108 Coiled ground portion

Claims (5)

A first frame;
A second frame facing the first frame;
A third frame disposed between the first frame and the second frame and positioned relative to the first frame;
A paper dust removing roller supported by the third frame;
A registration roller supported by the third frame and facing the paper dust removing roller;
A first wire connected to the paper dust removing roller;
A second wire conducted to the registration roller and the first wire;
A positioning biasing member that biases the third frame toward the first frame;
The image forming apparatus, wherein the positioning urging member is in contact with at least one of the first wire and the second wire and is electrically connected to a ground member provided in the second frame.   The image forming apparatus according to claim 1, wherein the first wire and the second wire are pressed by the positioning biasing member.   The image forming apparatus according to claim 1, wherein a portion where the first wire and the second wire overlap is pressed by the positioning biasing member.   The image forming apparatus according to claim 1, wherein the first frame and the second frame are made of resin.   The image forming apparatus according to claim 1, wherein the second frame is reinforced by a sheet metal as the ground member.

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