JP4289683B2 - Image forming apparatus and image reading apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus that reads an image of a document, and an image forming apparatus that has an image reading apparatus and has a function of forming a read image on a recording sheet.

  Conventionally, a sheet discharging mechanism such as an image forming apparatus incorporates a discharging member such as a discharging brush for removing static electricity charged on the surface of the sheet due to friction during conveyance. The static eliminator is electrically connected to the metal frame of the device, and the charge charged on the surface of the paper moves to the ground line in the control circuit of the device via the static eliminator and the frame, and the paper is neutralized. The

  Patent Document 1 discloses an image reading apparatus including a sheet conveying mechanism that electrically connects a static eliminating brush and a metal frame by a conductive leaf spring member. Patent Document 2 discloses an image forming apparatus including a paper transport mechanism that grounds a static elimination brush via a static elimination plate. Japanese Patent Application Laid-Open No. 2003-228561 discloses an image forming apparatus including a sheet conveying mechanism that attaches a neutralizing brush to a shaft of a paper discharge roller and grounds the neutralizing brush via the shaft. Patent Document 4 discloses an image forming apparatus including a paper transport mechanism in which a ground structure for removing a charge charged on a transport roller is incorporated. Patent Document 5 discloses an image forming apparatus including a paper transport mechanism that performs static elimination of a paper sheet using a static elimination sheet attached on a paper transport plate.

By the way, in an image reading apparatus provided with an original conveying mechanism that automatically conveys originals one by one, a platen roller is provided for conveying the original while being in close contact with an image reading sensor such as a contact image sensor. . In such an image reading apparatus, when a paper jam occurs around the platen roller, the upper cover of the image reading apparatus can be opened and closed in order to remove the jammed document. . In addition, in order to easily remove the document jammed between the platen roller and the image reading unit, the rotation shaft of the platen roller is pivotally supported so as to be movable in the direction in which the document is pressed (direction perpendicular to the document conveyance direction). Has been. Furthermore, since the platen roller needs to be in close contact with the original when the original is conveyed, the platen roller is biased toward the contact image sensor by an elastic member such as a coil spring.
JP 2003-48641 A Japanese Patent No. 3323582 JP 2000-38246 A Japanese Patent No. 3090256 JP-A-6-56301

  However, in the image reading apparatus having an elastic member for urging the platen roller in the direction of the contact image sensor, static electricity is removed by applying the technique disclosed in Patent Document 1 to Patent Document 5. However, the configuration around the platen roller becomes complicated, and not only the apparatus cannot be reduced in size but also the cost will be increased in the future.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and is capable of removing static electricity charged on a document by electrically connecting a static eliminating brush to a ground line in an apparatus circuit with a simple and inexpensive configuration. In addition, an object of the present invention is to provide an image forming apparatus in which a platen roller can be pressed against an image reading sensor with an appropriate force.

In order to achieve the above object, the invention of claim 1
A document feed tray for holding a loaded document, a document transport mechanism for transporting a document held in the document feed tray, and reading an image of the document transported by the document transport mechanism and converting it into an electrical signal An image reading unit having image reading means for performing
A recording paper feed tray for holding the loaded recording paper, a recording paper transport mechanism for transporting a document held in the recording paper feed tray, and an image on the recording paper transported by the recording paper transport mechanism An image forming unit having an image forming unit to form, and a recording paper discharge tray for holding a recording sheet on which an image is formed by the image forming unit;
A circuit board constituting a control circuit for controlling the document conveying mechanism, the image reading means, the recording paper conveying mechanism, and the image forming means ;
And a frame made of metals,
An openable / closable lid member covering the upper part of the image reading unit,
The document transport mechanism includes a pick roller for feeding a document held in the document feed tray to the inside of the image reading unit and a metal rotation shaft, and reads the document sent by the pick roller for the image reading. A platen roller that conveys in the discharge direction while pressing against the means, a resin bearing member that supports the vicinity of both ends of the rotation shaft of the platen roller and is movable in the direction in which the platen roller presses the document, and conductive The platen roller is attached to the lid member, and a first leaf spring member that is attached to the frame and has contact with the end surface of the rotation shaft of the platen roller and biases the rotation shaft in the axial direction. In an image forming apparatus having a static elimination brush for removing static electricity charged in a document conveyed by
The document transport mechanism is attached to the inside of the lid member in contact with the static elimination brush, and abuts against the rotation shaft of the platen roller when the lid member is closed, and the rotation shaft is used for the image reading. A second leaf spring member biasing in the direction of the means;
The second leaf spring member is formed by sheet metal processing a rectangular metal plate, a coupling portion coupled to the lid member, a first spring end portion in contact with the static elimination brush, and a platen roller A second spring end abutting against the rotating shaft;
The first spring end and the second spring end are formed adjacent to each other in parallel to the short side of the metal plate on the opposite side of the coupling portion of the rectangular metal plate, and Separated by a groove parallel to the long side of the metal plate,
The second leaf spring member is bent a plurality of times in parallel with the rotation axis of the platen roller from the coupling portion to the first spring end portion and the second spring end portion,
Static electricity charged on the document is conducted to the ground line formed on the circuit board through the static elimination brush, the second leaf spring member, the rotation shaft of the platen roller, the first leaf spring member, and the frame, and the lid When the member is closed, the rotation shaft of the platen roller is urged toward the image reading means by the second leaf spring member, and the platen roller is pressed toward the image reading means. is there.

The invention of claim 2
A document conveying mechanism that conveys a document, an image reading unit that reads an image of the document conveyed by the document conveying mechanism and converts it into an electrical signal, and a control circuit that controls the document conveying mechanism and the image reading unit comprising a circuit board, and a frame made of metals,
The document transport mechanism includes a metal rotating shaft that is electrically connected to the frame, and is charged with a platen roller that transports the document in a discharge direction while pressing the document against the image reading unit, and a document transported by the platen roller. In an image reading apparatus having a static elimination brush for removing static electricity,
The document transport mechanism has electrical conductivity, and further includes a spring member that abuts against the rotation shafts of the static elimination brush and the platen roller and biases the rotation shaft toward the image reading unit.

The invention of claim 3 is the image reading apparatus according to claim 2,
The spring member is formed by processing a rectangular metal plate into a sheet metal shape, and includes a first spring end that is brought into contact with the neutralizing brush and a second spring end that is brought into contact with the rotation shaft of the platen roller. Have
The first spring end and the second spring end are arranged in parallel to each other in parallel to the short side of the metal plate in the rectangular metal plate, and are grooves parallel to the long side of the metal plate. Separated by
It said spring member is one that is parallel to bent a plurality of times and the rotation axis of the front Symbol platen roller.

  According to the invention of claim 1, since the static elimination brush is electrically connected to the ground line formed on the circuit board via the second leaf spring member, the rotation shaft of the platen roller, the first leaf spring member, and the frame, With a simple and inexpensive configuration, the static elimination brush can be electrically connected to the ground line in the apparatus circuit, and static electricity charged on the original can be removed. Further, when the lid member is closed, the rotation axis of the platen roller is biased in the direction of the image reading means by the second leaf spring member, so that the platen roller is moved in the direction of the image reading means without increasing the cost. Therefore, the image can be accurately read and the document can be conveyed. When the paper jam occurs, the lid member is opened to move the second leaf spring member together with the lid member, and the platen roller can freely move in the direction opposite to the image reading means. Thereby, the document jammed in the vicinity of the platen roller can be easily removed. Further, since the second leaf spring member is made of a rectangular metal plate, and the first spring end and the second spring end are formed adjacent to each other in parallel to the short side of the metal plate, A large number of second leaf spring members can be formed from the original sheet of the metal plate, and the cost of the image forming apparatus can be further reduced. Further, since the second leaf spring member is bent a plurality of times in parallel with the rotation axis of the platen roller from the coupling portion to the first spring end portion and the second spring end portion, the first spring end portion and the static elimination brush In addition, the contact area between the second spring end and the rotation shaft of the platen roller can be increased, and the conduction can be ensured.

  According to the second aspect of the present invention, since the static elimination brush is electrically connected to the ground line formed on the circuit board via the spring member, the rotating shaft of the platen roller, and the frame, the static elimination brush has a simple and inexpensive configuration. Can be electrically connected to a ground line in the apparatus circuit, and static electricity charged on the original can be removed. Further, when the lid member is closed, the rotation axis of the platen roller is biased in the direction of the image reading means by the second leaf spring member, so that the platen roller is moved in the direction of the image reading means without increasing the cost. Therefore, the image can be accurately read and the document can be conveyed.

According to the invention of claim 3, the spring member is formed by sheet metal processing of a rectangular metal plate, and the first spring end and the second spring end are parallel to the short side of the metal plate. Since they are formed adjacent to each other, a large number of spring members can be formed from the original sheet of the metal plate, and the cost of the apparatus can be further reduced. The spring member, because the bent multiple times in parallel with the axis of rotation of the platen roller, to increase the contact area between the rotating shaft of the first spring end discharging brush and the second spring end and the platen roller And the conduction can be ensured.

  An image forming apparatus according to an embodiment for carrying out the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, the image forming apparatus 1 is connected to an image reading unit 2 that reads an image of a document and converts it into an electric signal, and an electric signal of the image read by the image reading unit 2 or the outside. An image forming unit 3 that forms an image on a recording sheet based on an electrical signal input from a device or the like, a control unit 4 that controls the image reading unit 2 and the image forming unit 3, and various commands to the user Is provided with an operation unit 5 for inputting the image, a metal frame 6 that supports each of the above-described units, and a lid member 7 that can be opened and closed to cover the upper part of the image reading unit 2.

  The image reading unit 2 includes a document feed tray 21 that holds a loaded document, a document transport mechanism 22 that transports a document held on the document feed tray 21, and a document transported by the document transport mechanism 22. It has a contact image sensor (image reading means) 23 for reading an image and converting it into an electrical signal. The document transport mechanism 22 discharges the document held on the document feed tray 21 to the inside of the image reading unit 2 and the document sent by the pick roller 24 while pressing the document on the contact image sensor 23. It has a platen roller 25 for conveying in the direction. The platen roller 25 is supported by a metal rotating shaft 25a and presses the document against the image reading surface 23a of the contact image sensor 23 while rotating integrally with the rotating shaft 25a. The document whose image has been read by the contact image sensor 23 is discharged from the document discharge unit 11.

  The image forming unit 3 includes a recording paper feed tray 31 that holds recording paper loaded by a user, a recording paper transport mechanism 32 that transports a document held in the recording paper feed tray 31, and a recording paper transport mechanism. The printing unit (image forming unit) 33 forms an image on the recording sheet conveyed by the printer 32, the recording sheet discharge tray 34 that holds the recording sheet on which the image is formed by the printing unit 33, and the like. Examples of the print unit 33 include an inkjet print engine and a laser beam print engine.

  The control unit 4 is realized by a control circuit composed of electronic components mounted on a circuit board 41 (see FIG. 3). The circuit board 41 is attached to the frame 6 via a metal screw 10. A land pattern 41a connected to the ground line is formed on the contact portion of the circuit board 41 with the screw 10, and the frame 6 is connected to the ground line of the circuit board 41 via the screw 10 and the land pattern 41a. Has been.

  The operation unit 5 includes an operation button operated by a user and a switch that is turned on / off according to the operation of the operation button, and displays an operation state of the image forming apparatus 1 and an image formed by the image forming apparatus 1. It is provided on the upper surface of the lid member 7 together with an LCD (Liquid Crystal Display).

  FIG. 2 shows a configuration around the platen roller 25 in the document transport mechanism 22. 3 shows a configuration around one end of the platen roller 25 and the circuit board 41, and FIG. 4 shows a configuration around the other end. 2A shows a state in which the lid member 7 is closed, and FIG. 2B shows a state in which the lid member 7 is opened. The lid member 7 is normally closed, and is opened when a jammed document is removed when a paper jam occurs around the platen roller 25.

  In addition to the pick roller 24 and the platen roller 25, the document conveying mechanism 22 includes a resin bearing member 26 that supports the vicinity of both ends of the rotation shaft 25a of the platen roller 25, and an end surface (first surface of the rotation shaft 25a of the platen roller 25 (first The first leaf spring member 27 (see FIG. 3) is in contact with the shaft end 25b side and biases the rotating shaft 25a in the axial direction (direction from the first shaft end 25b to the second shaft end 25c). ), A static elimination brush 28 for removing static electricity charged on the document conveyed by the platen roller 25, and the second shaft end side of the rotation shaft 25a of the platen roller 25 when the lid member 7 is closed. The second plate spring member 29 further biases the rotating shaft 25a in the direction of the contact image sensor 23 (arrow Y direction). The rotating shaft 25a of the platen roller 25, the first leaf spring member 27, the base portion 28a of the static elimination brush 28, and the second leaf spring member 29 are formed of a conductive metal material. In the present embodiment, the second leaf spring member 29 is provided only on the second shaft end portion 25c of the rotating shaft 25a. However, the second plate spring member 29 may be provided only on the first shaft end portion 25b. The structure provided in both the 1st axial end part 25b and the 2nd axial end part 25c may be sufficient.

  The bearing member 26 rotatably supports the rotation shaft 25a of the platen roller 25. In order to automatically adjust the distance between the platen roller 25 and the image reading surface of the contact image sensor 23 in accordance with the thickness of the document, the bearing member 26 moves the rotation shaft 25a of the platen roller 25 in the direction indicated by the arrow Y. A second spring member 29 is provided on the upper portion of the rotary shaft 25a.

  The first leaf spring member 27 is attached to the frame 6 by screws 8 and biases the first shaft end portion 25b of the rotation shaft 25a of the platen roller 25 in the direction of the second shaft end portion 25c. As a result, the backlash in the axial direction of the platen roller 25 can be eliminated, and the document can be accurately conveyed.

  The neutralizing brush 28 is attached to the inside of the lid member 7, and is arranged in parallel with the platen roller 25 on the downstream side of the platen roller 25 with the lid member 7 closed. . The structure of the static elimination brush 28 itself is the same as that of a well-known thing (For example, what was disclosed in the paragraph (0035) of the said patent document 3).

  The second leaf spring member 29 is formed by sheet metal processing the rectangular metal plate 30 shown in FIG. The second leaf spring member 29 is brought into contact with the coupling portion 29 a coupled to the lid member 7, the first spring end portion 29 b in contact with the base portion 28 a of the static elimination brush 28, and the rotation shaft 25 a of the platen roller 25. And a second spring end portion 29c. The first spring end portion 29b is attached to the inner surface of the lid member 7 with a screw 9 so that the first spring end portion 29b contacts the base portion 28a of the static elimination brush 28. On the other hand, the second spring end 29c comes into contact with the rotation shaft 25a of the platen roller 25 in a state where the lid member 7 is closed. When the lid member 7 is opened, the second spring end 29c moves upward together with the lid member 7 (see FIG. 2B), so that the platen roller 25 is moved upward in the direction opposite to the arrow Y direction in FIG. The document can be freely moved, so that the document jammed around the platen roller 25 can be easily removed.

  The first spring end portion 29 b and the second spring end portion 29 c are formed adjacent to each other in parallel to the short side of the metal plate 30 on the side opposite to the coupling portion 29 a of the metal plate 30. In the metal plate 30, a groove 30a that separates the first spring end portion 29b and the second spring end portion 29c is formed in parallel to the long side. The second leaf spring member 29 extends along the folding lines 30b, 30c, 30d, and 30e parallel to the rotation shaft 25a of the platen roller 25 from the coupling portion 29a to the first spring end portion 29b and the second spring end portion 29c. Formed by being bent multiple times.

  When the lid member 7 is closed, the second spring end 29c and the rotating shaft 25a of the platen roller 25 are in contact with each other. The spring member 29, the rotary shaft 25a of the platen roller 25, the first leaf spring member 27, the frame 6 and the screw 10 are connected to the ground line formed on the circuit board 41, and the lid member 7 is closed. During rotation, the rotation shaft 25 a of the platen roller 25 is urged in the direction of arrow Y by the second leaf spring member 29, and the platen roller 25 is pressed against the contact image sensor 23.

  According to the image forming apparatus 1 of the present embodiment having the above-described configuration, the static elimination brush 28 is interposed via the second leaf spring member 29, the rotation shaft 25 a of the platen roller 25, the first leaf spring member 27, and the frame 6. Therefore, the static elimination brush 28 can be electrically connected to the ground line in the control circuit with a simple and inexpensive configuration. Can be removed. Further, when the lid member 7 is closed, the rotation shaft 25a of the platen roller 25 is urged by the second leaf spring member 29 in the direction of the contact image sensor 23, that is, in the direction of the arrow Y, which increases costs. In addition, the platen roller 25 can be pressed against the contact image sensor 23 with an appropriate force, and the image reading and document feeding can be performed accurately. When a paper jam occurs, the second leaf spring member 29 moves together with the lid member 7 by opening the lid member 7, and the platen roller 25 can freely move in the direction opposite to the arrow Y direction. It becomes. Thereby, the document jammed in the vicinity of the platen roller 25 can be easily removed. Further, the second leaf spring member 29 is formed of a rectangular metal plate 30, and the first spring end portion 29b and the second spring end portion 29c are formed adjacent to each other in parallel to the short side of the metal plate 30. Thus, a large number of second leaf spring members 29 can be formed from the original sheet of the metal plate, and the cost of the image forming apparatus can be further reduced. In addition, the second leaf spring member 29 extends from the coupling portion 29a to the first spring end portion 29b and the second spring end portion 29c, and the fold lines 30b, 30c, 30d, and 30e are parallel to the rotation shaft 25a of the platen roller 25. Is bent a plurality of times along the line, so that the contact area between the first spring end 29b and the static eliminating brush 28 and the second spring end 29c and the rotation shaft 25a of the platen roller 25 can be increased, and the conduction is improved. It can be certain.

  The present invention is not limited to the configuration of the above-described embodiment, and at least the second spring member 29 causes the static elimination brush 28 and the rotation shaft 25a of the platen roller 25 to conduct, and static electricity charged on the original is eliminated by the static elimination brush 28 and the second. What is necessary is just to be comprised so that it may move to the ground line of the circuit board 41 through the spring member 29, the rotating shaft 25a, and the metal frame 6. FIG. The present invention can be variously modified. For example, the present invention is not limited to an image forming apparatus having an image reading function and an image forming function, and may be applied to an image reading apparatus having only an image reading function. .

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. (A) is a sectional side view showing the configuration around the platen roller in a state in which the lid member is closed, and (b) is a sectional side view in the state in which the lid member is opened. The top view which shows the structure of the 1st axial end part periphery of a platen roller. The perspective view which shows the structure of the 2nd axial end part periphery of a platen roller. The top view which shows the shape of the metal plate for forming a 2nd spring member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image reading part 3 Image forming part 6 Frame 7 Lid member 22 Original conveyance mechanism 23 Contact | adherence type image sensor (image reading means)
25 Platen roller 25a Rotating shaft 26 Bearing member 27 First leaf spring member 28 Static elimination brush 29 Second leaf spring member 29b First spring end portion 29c Second spring end portion 41 Circuit board

Claims (3)

A document feed tray for holding a loaded document, a document transport mechanism for transporting a document held in the document feed tray, and reading an image of the document transported by the document transport mechanism and converting it into an electrical signal An image reading unit having image reading means for performing
A recording paper feed tray for holding the loaded recording paper, a recording paper transport mechanism for transporting a document held in the recording paper feed tray, and an image on the recording paper transported by the recording paper transport mechanism An image forming unit having an image forming unit to form, and a recording paper discharge tray for holding a recording sheet on which an image is formed by the image forming unit;
A circuit board constituting a control circuit for controlling the document conveying mechanism, the image reading means, the recording paper conveying mechanism, and the image forming means ;
And a frame made of metals,
An openable / closable lid member covering the upper part of the image reading unit,
The document transport mechanism includes a pick roller for feeding a document held in the document feed tray to the inside of the image reading unit and a metal rotation shaft, and reads the document sent by the pick roller for the image reading. A platen roller that conveys in the discharge direction while pressing against the means, a resin bearing member that supports the vicinity of both ends of the rotation shaft of the platen roller and is movable in the direction in which the platen roller presses the document, and conductive The platen roller is attached to the lid member, and a first leaf spring member that is attached to the frame and has contact with the end surface of the rotation shaft of the platen roller and biases the rotation shaft in the axial direction. In an image forming apparatus having a static elimination brush for removing static electricity charged in a document conveyed by
The document transport mechanism is attached to the inside of the lid member in contact with the static elimination brush, and abuts against the rotation shaft of the platen roller when the lid member is closed, and the rotation shaft is used for the image reading. A second leaf spring member biasing in the direction of the means;
The second leaf spring member is formed by sheet metal processing a rectangular metal plate, a coupling portion coupled to the lid member, a first spring end portion in contact with the static elimination brush, and a platen roller A second spring end abutting against the rotating shaft;
The first spring end and the second spring end are formed adjacent to each other in parallel to the short side of the metal plate on the opposite side of the coupling portion of the rectangular metal plate, and Separated by a groove parallel to the long side of the metal plate,
The second leaf spring member is bent a plurality of times in parallel with the rotation axis of the platen roller from the coupling portion to the first spring end portion and the second spring end portion,
Static electricity charged on the document is conducted to the ground line formed on the circuit board through the static elimination brush, the second leaf spring member, the rotation shaft of the platen roller, the first leaf spring member, and the frame, and the lid When the member is closed, the rotation shaft of the platen roller is urged in the direction of the image reading means by the second leaf spring member, and the platen roller is pressed in the direction of the image reading means. An image forming apparatus. A document conveying mechanism that conveys a document, an image reading unit that reads an image of the document conveyed by the document conveying mechanism and converts it into an electrical signal, and a control circuit that controls the document conveying mechanism and the image reading unit comprising a circuit board, and a frame made of metals,
The document transport mechanism includes a metal rotating shaft that is electrically connected to the frame, and is charged with a platen roller that transports the document in a discharge direction while pressing the document against the image reading unit, and a document transported by the platen roller. In an image reading apparatus having a static elimination brush for removing static electricity,
The document conveying mechanism has electrical conductivity, and further includes a spring member that abuts against a rotation shaft of the static elimination brush and the platen roller and biases the rotation shaft toward the image reading unit. An image reading apparatus. The spring member is formed by processing a rectangular metal plate into a sheet metal shape, and includes a first spring end that is brought into contact with the neutralizing brush and a second spring end that is brought into contact with the rotation shaft of the platen roller. Have
The first spring end and the second spring end are arranged in parallel to each other in parallel to the short side of the metal plate in the rectangular metal plate, and are grooves parallel to the long side of the metal plate. Separated by
It said spring member includes an image reading apparatus according to claim 2, characterized in that bent parallel to the rotation axis a plurality of times before Symbol platen roller.

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