JP5618077B2 - Image forming apparatus - Google Patents

Description

  The present invention includes a housing that houses a document reading unit and an image forming unit, a document supply unit that is movable between an open state in which the top surface of the housing is opened and a closed state that covers the top surface, and a document supply unit And an open / close sensor that detects an open / closed state of the image forming apparatus.

  An image forming apparatus such as a copying machine is provided with a document reading device for reading an image of a document. This type of document reading apparatus is configured such that a document reading unit including a light source that emits light toward a document and a light receiving unit that receives reflected light from the document is housed in a housing. .

  For example, a glass plate is formed on the upper surface of the housing, and light is emitted from a light source in the housing to a document placed on the glass plate, and reflected light from the document is received by a light receiving unit. Is done. In addition, an opening / closing cover that can be opened and closed between a closed state facing the glass plate and an open state not facing the glass plate is attached to the casing. Hinges are fixed to both ends of the open / close cover, and the two hinges are attached to the housing, so that the open / close cover can be rotated around the hinge.

  The open / close cover is provided with a document supply device (ADF) for supplying a document to the document reading unit. The document feeder includes various rollers for transporting a document, and driving parts such as a motor and a gear for rotating these rollers. For this reason, when the document is supplied to the document reading unit, the driving component and the document are rubbed against each other, and static electricity is easily generated in the document supply device. Static electricity has an adverse effect on the apparatus, and causes troubles such as a read image being distorted or the apparatus being stopped.

  Therefore, as a countermeasure against such static electricity, it is required that the document feeder is properly grounded. As a method of grounding the document supply device, a method of connecting the document supply device to the housing with a wire is known. Japanese Patent Application Laid-Open No. 2004-228561 provides an image forming apparatus in which an image forming apparatus main body is provided with a grounding conductive part that can be freely moved and brought into contact with the conductive part of the automatic document conveying apparatus to enhance the grounding of the automatic document conveying apparatus. An apparatus is disclosed.

JP 2007-158743 A

  However, in both the known method using a wire and the method of Patent Document 1 in which a grounding conductive portion is provided, it is necessary to separately provide a dedicated member for grounding, which increases costs and complicates the assembly process. It was connected.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an image forming apparatus capable of reliably grounding a document supply unit without separately providing a dedicated member for grounding.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
An original reading unit for reading an image of the original;
An image forming unit for forming the read image on recording paper;
A housing that houses the document reading unit and the image forming unit;
A document supply that rotates about one side of the upper surface of the housing and is movable between an open state in which the upper surface is opened and a closed state that covers the upper surface, and supplies the document to the document reading unit. And
An open / close sensor having a detection member that projects upward from the housing in the open state and is pressed down by the original supply unit in the closed state to detect an open / closed state of the original supply unit. And
The detection member is made of a conductive material, and when the document supply unit is opened and closed, the leading end of the detection member comes into contact with the conductive unit of the document supply unit, thereby electrically connecting the document supply unit and the housing. It is characterized by that.

  The image forming apparatus of the present invention includes an open / close sensor for detecting an open / close state of the document supply unit. The open / close sensor has a detection member that projects upward from the housing when the document supply unit is open, and is opened and closed by the document supply unit when the document supply unit is closed. The state can be detected. In the present invention, since the detection member is made of a conductive material, the leading end portion of the detection member comes into contact with the conductive portion of the document supply unit by moving the document supply unit from the open state to the closed state. And the casing can be made conductive. As a result, since the casing is normally grounded, static electricity generated in the document supply section can escape to the ground via the conductive section, the detection member, and the casing, and the document supply section can be reliably grounded. it can. Furthermore, the open / close sensor that detects the open / closed state of the document supply unit also serves to ground the document supply unit, and according to the present invention, there is no need to separately provide a dedicated member for grounding.

  In the image forming apparatus according to the aspect of the invention, it is preferable that the open / close sensor is provided on one side of the housing, and the document supply unit includes an electronic circuit board at a position facing the open / close sensor in the closed state.

  By providing the open / close sensor on one side of the housing, the wiring of the open / close sensor can be simplified. Further, the wiring for grounding can be shortened by arranging the open / close sensor and the electronic circuit board of the document supply unit close to each other.

  In the image forming apparatus of the present invention, the conductive portion is a sheet metal part to which a conveyance drive unit for conveying a document is fixed, and the main body cover of the document supply unit has an opening for exposing the sheet metal part. It is preferable to provide.

  According to this configuration, since the detection member comes into contact with the sheet metal part to which the conveyance drive unit is fixed through the opening provided in the main body cover of the document supply unit, the static electricity generated in the document supply unit is reliably enclosed. Can escape to the body side.

1 is a schematic cross-sectional view showing an internal configuration of an image forming apparatus. 1 is a perspective view of an image forming apparatus in which a document supply unit is opened. It is a perspective sectional view near the open / close sensor. It is a longitudinal cross-sectional view near the open / close sensor. It is a figure which shows the detailed structure of a detection member and a sensor part.

  FIG. 1 is a schematic sectional view showing an internal configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view of the image forming apparatus with the document supply unit opened.

  The image forming apparatus 1 according to the present embodiment is roughly composed of a housing 1a and an ADF 2 (corresponding to a document supply unit) disposed above the housing 1a. The housing 1a accommodates therein a document reading unit 3 that reads an image of a document, which will be described later, and an image forming unit 4 that forms the read image on a recording sheet.

  The casing 1a has a substantially rectangular parallelepiped shape, and is composed of a resin molded product, a metal sheet metal part, and the like.

  The ADF 2 includes a document tray 2a, and one document can be placed on the document tray 2a, or two or more documents can be placed in a stacked state. The ADF 2 feeds the originals placed on the original tray 2a one by one by the pickup roller 2b and the separating means (a pair of separating roller and retard roller) 2c. The sent document is transported along a transport path 2g by a plurality of transport rollers 2d, 2e, and 2f, and an image is read by a stationary scanner 3a at a reading point A located in the middle of the transport path 2g. In addition to the motor and gear for rotating the various rollers, an electronic circuit board is provided inside the ADF 2. A document discharge tray 2i is formed on the upper surface of the ADF 2, and a document tray 2a is provided above the document discharge tray 2i.

  The ADF 2 provided in the image forming apparatus 1 shown in FIG. 1 is a single-sided reading type that can read only one side of an original, and the original after the single-sided image is read is discharged by a discharge roller 2h. The documents are sequentially discharged onto the document discharge tray 2i. In addition to the single-sided scanning type as shown in FIG. 1, the ADF 2 may be a double-sided scanning type provided with a double-sided scanning mechanism that can scan both sides of the document by inverting the front and back of the document. Since the configuration of such a double-sided scanning type ADF 2 is known, a detailed description thereof will be omitted.

  The document reading unit 3 employs a so-called CCD system, and a plurality of CCDs (Charge Coupled Devices) are arranged in a main scanning direction which is a horizontal direction (front-rear direction in FIG. 1) perpendicular to the document transport direction. They are arranged side by side. The original reading unit 3 includes a stationary reading area 3b for reading an original conveyed by the ADF 2 while the scanner 3a is stationary, and a moving reading area 3c for reading an original placed on the glass plate 3d while the scanner 3a moves. Is provided.

  FIG. 1 shows a state in which the scanner 3a is stationary in a stationary reading area 3b immediately below the reading point A and reads an image of a document conveyed by the ADF 2 one by one. When the original is read in the stationary reading area 3b, main scanning is performed by receiving reflected light from the original with each CCD, and sub-scanning is performed by conveying the original through the reading point A. On the other hand, when the original is read in the movable reading area 3c, main scanning is performed by receiving reflected light from the original with each CCD, and the scanner 3a is in a horizontal direction (sub-scanning direction) orthogonal to the main scanning direction. Sub-scanning is performed by moving to.

  The image forming unit 4 includes a photosensitive drum 4a, a charger 4b, an optical writing unit 4c, a developing unit 4d, a transfer unit 4e, and a fixing unit 4f, and forms an image on the recording paper P by an electrophotographic method. A photoconductor is formed on the surface of the photoconductor drum 4a. During image formation, the surface of the photoconductor drum 4a that is rotationally driven is uniformly charged by the charger 4b. The optical writing unit 4c outputs light from an LED (Light-Emitting Diode) or a laser light source based on image data of a document read by the scanner 3a. An electrostatic latent image is formed on the surface of the photosensitive drum 4a uniformly charged by the charger 4b by exposure with light output from the optical writing unit 4c.

  A toner image is formed on the surface of the photosensitive drum 4a on which the electrostatic latent image has been formed by adhering the toner supplied from the developing device 4d, and this toner image is formed on the recording paper P using the transfer device 4e. Transcribed. The recording paper P to which the toner image has been transferred is subjected to a heat treatment and a pressure treatment by the fixing device 4f, and is then discharged from the discharge roller 4g onto the discharge tray 4h.

  The paper supply unit 5 includes a recording paper cassette 6 for storing the recording paper P. The recording paper P is stored in a stacked state on a support plate 9 provided in the recording paper cassette 6. Can be done. The support plate 9 is rotatable around a support shaft 9a provided at one end thereof, and the end opposite to the support shaft 9a is biased upward by a compression spring 9b. The uppermost recording paper P is pressed against the paper feed roller 8. In this state, when the paper feed roller 8 is rotationally driven, the recording paper P stored in the recording paper cassette 6 is sent out to the transport path 12 one by one.

  The transport path 12 is provided with one or a plurality of transport rollers 13. The recording paper P sent out one by one from the recording paper cassette 6 is transported in the transport path 12 by the transport roller 13 and is sent to the image forming unit 4. Then, the recording paper P is temporarily stopped immediately before the photosensitive drum 4a, and is sent out by the registration roller 14 in accordance with the timing at which the toner image formed on the photosensitive drum 4a is transferred.

  The document reading unit 3, the image forming unit 4, and the paper feeding unit 5 as described above are arranged in the housing 1a, and the glass plate 3d is formed on the upper surface of the housing 1a. An ADF 2 is provided above the housing 1a.

  The housing 1a and the ADF 2 are connected by a plurality of hinges provided along one side S of the housing 1a. One end of the hinge is attached to the rear end in the front-rear direction (main scanning direction) on the upper surface of the housing 1a, and the other end of the hinge is attached to the lower surface of the ADF 2. The ADF 2 rotates around the one side S side of the upper surface of the housing 1a, and can move between an open state in which the upper surface is opened and a closed state in which the upper surface is covered.

  When the ADF 2 is used, the ADF 2 is closed as shown in FIG. 1, and the originals placed on the original tray 2a in this state are supplied to the original reading unit 3 one by one. On the other hand, when the ADF 2 is not used, that is, when an original is placed on the glass plate 3d to be read, the ADF 2 is closed after the ADF 2 is placed on the glass plate 3d in an open state as shown in FIG. Thus, the document is read while being sandwiched between the lower surface of the ADF 2 and the glass plate 3d.

  The image forming apparatus 1 includes an open / close sensor 7 for detecting the open / closed state of the ADF 2. The open / close sensor 7 is provided on one side S of the housing 1a. The open / close sensor 7 is provided at one end in the sub-scanning direction so as not to interfere with the document reading unit 3.

  3 is a perspective sectional view of the vicinity of the open / close sensor 7, and FIG. 3 and 4, ADF 2 is in an open state. The open / close sensor 7 has a detection member 71 that projects upward from the housing 1a when the ADF 2 is open and detects the open / close state of the ADF 2 by being pushed down by the ADF 2 when the ADF 2 is closed.

  The detection member 71 has a rectangular bar shape in cross section, and can slide in the vertical direction inside the cylindrical frame 72 fixed in the housing 1a. The detection member 71 is made of a conductive material such as metal or conductive resin. The detection member 71 of the present embodiment is a sheet metal part made of a metal material. Examples of the metal material of the detection member 71 include an electrogalvanized steel plate (SECC) and a stainless steel plate. The front end portion 71a of the detection member 71 is processed by sheet metal so as to form a triangle when viewed from the sub-scanning direction, and the leading edge is slightly rounded. However, the tip 71a of the detection member 71 may be hemispherical.

  The detection member 71 is pushed upward by a coil spring 73. The coil spring 73 has one end fixed to the cylindrical frame 72 and the other end fixed to the lower portion of the detection member 71. The coil spring 73 is made of conductive metal and is electrically connected to the grounded casing 1a. A stopper 71d that is slightly larger than the rod-shaped portion is provided below the detection member 71. The upward movement of the detection member 71 is restricted by the cylindrical frame 72, and the tip of the detection member 71 is opened when the ADF 2 is open. A part protrudes from the upper surface of the housing 1a. On the other hand, in the closed state of the ADF 2, the detection member 71 is pushed down by the lower surface of the ADF 2, and substantially entirely buried in the housing 1 a.

  FIG. 5 is a diagram illustrating a detailed configuration of the detection member 71 and the sensor unit 74. (A)-(c) shows the state when the detection member 74 is pushed down by the lower surface of ADF2, (d) is a top view of the detection member 71 and the sensor part 74. FIG.

  A sensor unit 74 is provided below the detection member 71, and the vertical position of the detection member 71 can be detected. A first plate 71 a and a second plate 71 b are integrated with the detection member 71, and these plates 71 a and 71 b also move up and down integrally with the detection member 71. The vertical length of the first plate 71a is set to be shorter than the vertical length of the second plate 71b.

  The sensor unit 74 includes a first detection sensor 75 on the first plate 71a side and a second detection sensor 76 on the second plate 71b side. The first detection sensor 75 includes a light emitting unit 75a and a light receiving unit 75b, and is in a positional relationship so as to sandwich the first plate 71a. The second detection sensor 76 includes a light emitting unit 76a and a light receiving unit 76b, and is in a positional relationship so as to sandwich the second plate 71b.

  When the plates 71a and 71b are positioned between the light emitting portions 75a and 76a and the light receiving portions 75b and 76b, the light is blocked, but when the plates 71a and 71b are lowered, the light receiving portions 75b and Light reaches 76b. Thereby, the timing can be detected.

  The first detection sensor 75 detects whether or not the ADF 2 is opened by a predetermined angle. In other words, when the ADF 2 is gradually closed from a state where it is largely opened, the first plate 71a is retracted from the first detection sensor 75 and can receive light when the predetermined angle is reached (FIG. 5B). reference). The predetermined angle can be appropriately set within a range of 15 ° to 25 °, for example.

  The second detection sensor 76 detects immediately before or when the ADF 2 is closed (see FIG. 4C). Immediately before closing, for example, the angle between the ADF 2 and the glass plate 3d of the document reading unit 3 is 5 ° or less, and the closed state is 0 °. That is, the second detection sensor 76 has a function of detecting whether the ADF 2 is closed or closed.

  In the above embodiment, the timing is detected by shifting from the light blocking state to the light passing state. However, the timing may be detected by shifting from the light passing state to the light blocking state.

  The distal end portion 71a of the detection member 71 comes into contact with the conductive portion of the ADF 2 as the ADF 2 is opened and closed. The conductive portion of the present embodiment is a sheet metal part 21 to which a conveyance drive unit for conveying a document is fixed. The transport drive unit includes a roller, a gear, a motor, an electronic circuit board, and the like for transporting the document, and is built in the ADF 2. The electronic circuit board is preferably disposed at a position facing the open / close sensor 7 in the closed state of the ADF 2. Examples of the material of the sheet metal part 21 include an electrogalvanized steel plate (SECC) and a stainless steel plate.

  The body cover 22 of the ADF 2 is usually a resin molded product. Therefore, the main body cover 22 includes an opening 22a through which the sheet metal part 21 is exposed so that the tip 71a of the detection member 71 and the sheet metal part 21 can be in direct contact with each other. The opening 22a is provided at a position facing the detection member 71 when the ADF 2 is closed.

  As the ADF 2 is opened and closed, the tip 71a of the detection member 71 and the sheet metal part 21 of the ADF 2 come into contact with each other. To escape to the earth. The open / close sensor 7 that detects the open / closed state of the ADF 2 also serves to ground the ADF 2, and according to the present invention, it is not necessary to separately provide a dedicated member for grounding. The ADF 2 is used in the closed state, that is, the ADF 2 transports the document by driving the transport driving unit in the closed state. In the closed state, the tip 71a of the detection member 71 and the sheet metal part 21 of the ADF 2 are in contact with each other, so that the ADF 2 can be securely grounded and static electricity generated when the document is conveyed can be reliably removed.

<Another embodiment>
In the present embodiment, static electricity generated in the ADF 2 is released to the housing 1a via the coil spring 73. However, the static electricity generated from the ADF 2 may be directly released from the detection member 71 to the housing 1a without using the coil spring 73. Good.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 1a Case 2 ADF
DESCRIPTION OF SYMBOLS 3 Original reading part 3d Glass plate 4 Image formation part 7 Opening / closing sensor 21 Sheet metal part 22 Main body cover 22a Opening part 71 Detection member 71a Tip part 71d Stopper 72 Cylindrical frame 73 Coil spring 74 Sensor part P Recording paper S Upper surface of housing | casing One side

Claims (2)

An original reading unit for reading an image of the original;
An image forming unit for forming the read image on recording paper;
A housing that houses the document reading unit and the image forming unit;
A document supply that rotates about one side of the upper surface of the housing and is movable between an open state in which the upper surface is opened and a closed state that covers the upper surface, and supplies the document to the document reading unit. And
An open / close sensor having a detection member that projects upward from the housing in the open state and is pressed down by the original supply unit in the closed state to detect an open / closed state of the original supply unit. And
The detection member is made of a conductive material, and when the document supply unit is opened and closed, the leading end of the detection member comes into contact with the conductive unit of the document supply unit, thereby electrically connecting the document supply unit and the housing. ,
The conductive portion is a sheet metal part to which a transport drive unit for transporting a document is fixed,
Body cover of the document feeding unit, an image forming apparatus according to claim Rukoto an opening that exposes the sheet metal part. The open / close sensor is provided on one side of the housing,
The image forming apparatus according to claim 1, wherein the document supply unit includes an electronic circuit board in a position facing the open / close sensor in the closed state.

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