JP2008151932A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus allowing an original platen to be easily raised without complicating an original cover sheet. <P>SOLUTION: The image forming apparatus is equipped with: a main body part A having a document placing surface on which an original is placed on its upper surface; and the original platen openable/closable relative to the upper surface of the main body part A, and is equipped with: a first original scale 14 arranged in both sides on the upper surface at the depth from the front side of the main body part A; a second original scale 15 arranged perpendicularly to the first original scale 14 on the upper surface at the left side as seen from the front side of the main body part A; the document placing surface provided on the front side area of the first original scale 14 and the right side area of the second original scale 15; and the rectangular original cover sheet 13 attached to the lower surface side of the original platen B and set in an area smaller than the area of the document placing surface. The original cover sheet 13 is attached while at least one corner 13a among four corners of the original cover sheet 13 is lifted, so as to form space S between the corner 13a and the document placing surface when the original cover part B is closed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus including a main body having an original placement surface on which an original is placed, and a pressure plate that can be opened and closed with respect to the upper surface of the main body.

  Such an image forming apparatus (facsimile device, digital multi-function peripheral, copier, etc.) has a pressure plate portion so that an original can be placed on the original placement surface provided on the upper surface of the main body, and the placed original can be pressed. It is comprised so that opening and closing is possible with respect to the upper surface of a main-body part. The hinge part for opening and closing the pressure plate part is provided on the back side of the main body part, and the pressure plate part can be opened and closed by the operation part on the near side.

  In order to place a document on the document placement surface and press the document in a state where the pressure plate portion is closed, a document pressure sheet is attached to the lower surface side of the pressure plate portion, and the document pressure sheet places the document on the document placement surface. Press against. In this state, the original image is read, and when the reading operation is finished, the pressure plate is lifted to remove the original.

  When the pressure plate portion is closed, the document pressing sheet is attracted to the document placement surface (usually a glass surface), and thus there is a problem that a large force is required when lifting the pressure plate portion. Therefore, it is necessary to devise a device for reducing the force when lifting the pressure plate portion. For example, a document pressing device disclosed in Patent Document 1 is known.

  This document pressing device is provided with a rectangular document pressing sheet formed of a polyester film or the like, and slits are formed in the vicinity of the left and upper edges of the sheet. Further, the left side portion and the upper side portion of the sheet are bent obliquely upward to give a bending habit. When the original is pressed by the original pressing sheet, a space is formed around the original pressing sheet due to the bending behavior. Further, the document is pressed in a state where the folding behavior is provided on the document scale. As a result, air can easily enter between the original pressing sheet and the original placement surface, and the pressure plate part can be easily lifted.

Japanese Patent Laid-Open No. 10-307346

  However, according to the above configuration, it is necessary to form a slit in the original pressing sheet or to give a folding habit, which increases the processing cost of the original pressing sheet. Further, there is a problem that the original pressing sheet is easily damaged by forming the slit.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image forming apparatus configured to easily lift the pressure plate portion without performing complicated processing on the original pressing sheet.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
An image forming apparatus comprising: a main body having an original placement surface on which an original is placed; and a pressure plate that can be opened and closed with respect to the upper surface of the main body.
A first document scale disposed in the left-right direction on the upper surface on the back side when viewed from the front side of the main body operation;
A second document scale disposed at a right angle to the first document scale on the upper surface on the left side when viewed from the front side of the main body;
A front area of the first original scale, and the original placement surface provided in the right area of the second original scale;
A rectangular document pressing sheet attached to the lower surface side of the pressure plate portion and set in an area narrower than the area of the document placement surface,
At least one of the four corners of the original pressing sheet is attached in a state of being lifted upward, and a gap is formed between the corner and the original placement surface with the pressure plate portion closed. is there.

  The operation and effect of the image forming apparatus will be described. The image forming apparatus includes a main body and a pressure plate that is opened and closed with respect to the main body. With the pressure plate raised, the original is placed on the original placement surface provided on the upper surface of the main body, and after the pressure plate is closed, the original image is read. The upper surface of the main body is provided with a first document scale disposed on the back side in the left-right direction and a second document scale disposed on the left side, and the first document scale and the second document scale are orthogonal to each other. A document is placed using these document scales as a reference or index. That is, the near side area of the first document scale and the right area of the second document scale function as a document placement surface.

  The size of the rectangular document pressing sheet attached to the lower surface side of the pressure plate portion is set to be narrower than the area of the document placement surface. Therefore, the original pressing sheet does not run on the original scale, and no excessive force acts on the original pressing sheet. Further, at least one corner of the squares of the original pressing sheet is attached in a state where it is lifted upward. That is, the original is pressed by an area that is not lifted upward, but the corner is lifted by a corner, so that the pressing function of the original is not deteriorated. By lifting the corner, when the pressure plate portion is closed, a gap is formed between the corner portion and the document placement surface. Since air can enter the gap, the pressure plate portion can be easily lifted. There may be at least one corner to be lifted upward, and it may be configured to lift all four corners at the maximum. Further, the original pressing sheet need not be complicatedly processed and may be a normal rectangular sheet. As a result, it is possible to provide an image forming apparatus configured to easily lift the pressure plate unit without performing complicated processing on the document pressing sheet.

  In the present invention, it is preferable that an elastic sheet member for attachment is provided on the back side of the original pressing sheet, and the thickness of the portion corresponding to the corner of the elastic sheet member is set thinner than the surroundings.

  An elastic sheet member is provided on the back side of the original pressing sheet. When the original is pressed by the pressure plate portion, a pressing force is applied by compressing the elastic sheet member. Bonding of the original pressing sheet and the elastic sheet member, and bonding of the elastic sheet member and the pressure plate main body can be performed by an appropriate method such as an adhesive or a double-sided tape. By reducing the thickness of the portion corresponding to the corner of the elastic sheet member, the original sheet can be attached with the corner of the original pressing sheet raised upward by the amount of the reduced thickness. Therefore, the original pressing sheet can be mounted with its corners raised upward without complicated processing.

  In the present invention, it is preferable that the at least one corner includes a corner on the right side when viewed from the front side of the operation.

  The corner on the right-hand side is the corner farthest from the intersection of the first and second document scales. By mounting this corner in a lifted state, the lifting force can be most effectively reduced. In addition, since the operating part that opens and closes the pressure plate is provided on the front side, air can easily enter by lifting the corner on the front side, reducing the force when lifting the pressure plate Can be made.

  An image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an external configuration of the image forming apparatus. FIG. 2 is an external perspective view of the state where the pressure plate portion is opened. In the following description, the side on which the operation panel unit 5 of the image forming apparatus is provided is the front side of the operation, the side on which the hinge mechanism 6 is provided is the operation back side, and a person operates the operation panel unit 5 or the pressure plate unit B. The right hand side of the person is defined as the right side of the apparatus, and the left hand side of the person is defined as the left side of the apparatus.

  This image forming apparatus is roughly composed of a main body part A and a pressure plate part B. Inside the main body A, main mechanisms necessary for image formation are provided. The recording paper cassette 1 stores recording paper of a predetermined size such as A3 and A4. The recording paper cassette 1 is configured to be able to be inserted and removed from the front side of the main body A.

  The image recording unit 2 includes an electrophotographic recording device inside the main body A, and includes a photosensitive drum, a charger, a laser light writing unit, a developing device, a transfer device, a fixing device, and the like. The recording paper fed from the recording paper cassette 1 forms an image in the image recording unit 2 and is discharged to the discharge tray 3.

  The image reading unit 4 includes an ADF reading unit 4a located at the left end of the apparatus and a flat head scanner unit (FBS) 4b. The ADF reading unit 4a reads an image of a document sent by an automatic document feeder (ADF) 10 provided in the pressure plate unit B. The FBS 4b is provided with a platen glass 4c (corresponding to a document placement surface) on the upper surface, and a document is placed on the top. A reading scanning device (line sensor) (not shown) is provided below (inside) the platen glass 4c, and reads a document image while moving left and right below the platen glass 4c. When the original image is read by the ADF reading unit 4a, the original image conveyed by the ADF 10 is read with the reading and scanning device being stopped at that position.

  The operation panel unit 5 is provided on the upper part of the main body unit A so as to project to the near side. The operation panel unit 5 is provided with operation display units using various operation buttons and liquid crystal. The operation panel unit 5 performs various operations such as setting the number of copies, recording paper, and FAX transmission settings.

  The pressure plate portion B can be opened and closed by a hinge mechanism 6 provided on the back side of the main body portion 1. In order to place a document on the platen glass 4c, the platen B is lifted upward to open the surface of the platen glass 4c. The same applies when taking out the document. A document tray 11 is provided along with the ADF 10 on the upper portion of the pressure plate portion B. By placing the document on the document tray 11, the document can be transported by the ADF 10, and the image is read by the ADF reading unit 4a.

  The appearance of the pressure plate portion B is constituted by a platen cover 12. A document pressing sheet 13 is attached to the back surface of the platen cover 12, and presses the document placed on the platen glass 4b. The document pressing sheet 13 is a rectangular (rectangular) white sheet, and is made of, for example, a polyester resin. The original pressing sheet 13 has four corners, and a corner 13a on the right front side is attached in a state where it is lifted slightly upward. This point will be described later.

  A first document scale 14 and a second document scale 15 are provided on the upper surface of the main body A. The first document scale 14 is disposed in the left-right direction on the operation back side, and the second document scale 15 is disposed on the left side from the operation back side toward the front side. The first and second document scales 14 and 15 are arranged in an orthogonal state, and the front area of the first document scale 14 and the right area of the second document scale 15 function as a document placement surface. When placing a document, the document is placed on the basis of the first and second document scales 14 and 15.

  The first and second document scales 14 and 15 display the size of the document (for example, A4 and A3), and the document is placed in accordance with this display. The first document scale 14 and the second document scale 15 may be separate components, or both may be configured as one component.

<Configuration of document pressing sheet>
Next, the document pressing sheet 13 and its mounting structure will be described. FIG. 3 is a perspective view showing the configuration of the back side of the pressure plate B. FIG. 4 is a partial cross-sectional view showing a state where the pressure plate portion B is closed. FIG. 5 is a diagram showing the configuration of the back side of the document pressing sheet 13.

  An elastic sheet member 16 is coupled to the back side of the document pressing sheet 13, and the elastic sheet member 16 has a rectangular shape substantially the same as that of the document pressing sheet 13. An elastic attachment member 17 is further coupled to both ends of the elastic sheet member 16 in the left-right direction. The left elastic attachment member 17 has a rectangular shape extending in the front-rear direction. The right side elastic mounting member 17 also has a rectangular shape extending in the front-rear direction, but the front corner 17a is notched. These parts constitute a document pressing unit U.

  The original pressing sheet 13, the elastic sheet member 16, and the elastic attachment member 17 can be combined by an appropriate method such as an adhesive or a double-sided tape. The document pressing unit U is attached to the back side of the platen cover 12, but can be coupled with a double-sided tape or the like. Therefore, double-sided tape is laminated on the coupling surface 17 b of the elastic mounting member 17. A double-sided tape is also laminated on the corner 17a which is a cutout portion. Accordingly, if the corners 13a of the original pressing sheet 13 are combined so as to be pressed against the back side of the platen cover 12, the corners 13a can be attached with the corners 13a lifted upward.

  FIG. 4 shows a state where the platen B is closed and the document is pressed. Since the pressure plate portion B is closed in a state where the elastic sheet member 16 and the elastic attachment member 17 are elastically compressed, the original can be reliably pressed. The elastic sheet member 16 and the elastic attachment member 17 may be anything as long as they can apply a pressing force. For example, a foam sheet (sponge-like one) can be used. As shown in FIG. 4, since the corner 13a of the original pressing sheet 13 is lifted upward, a space S is formed between the original pressing sheet 13 and the platen glass 4c (original placement surface). .

  By forming such a space S, when the pressure plate part B is opened, air enters from the space S and it becomes easy to lift the pressure plate part B. If there is no such space S, the original pressing sheet 13 is in close contact (adsorption) with the platen glass 4c, and a large force is required to lift the pressure plate portion B, and the operability is lowered.

  Next, the size of the original pressing sheet 13 will be described with reference to FIG. The document pressing sheet 13 is set to a size smaller than that of the platen glass 4 c, and the upper side and the left side thereof are located slightly inside the first and second document scales 14 and 15. In other words, when the pressure plate part B is closed, the upper edge and the left edge of the original pressing sheet 13 do not cover the first and second original scales 14 and 15. Therefore, the original pressing sheet 13 does not need to be bent and can be produced as a simple rectangular sheet. The inner side of the upper side and the left side can be determined in consideration of component accuracy and assembly accuracy, but it is preferable to make them as close as possible.

  The reading area C is indicated by a broken line in FIG. 6, and the size of the original pressing sheet 13 is set to a size that can cover the reading area C (particularly, the right side and the lower side). The size of the reading area C is set larger than the maximum readable document size. The corner 13a is located farthest from the reference point P that is the intersection of the first and second original scales 14 and 15, that is, in the diagonal direction. When only one corner 13a is provided, it is most effective to provide it at this position. The corner 13a (the portion to be lifted up) is not limited to one, and can be provided at a maximum of four locations. Also in the case of providing two or three, it is preferable to include the corner 13a on the right front side.

  Further, it is preferable that the area where the corner 13a is provided does not overlap the reading area C. As a result, even a document of a maximum readable size can be reliably pressed.

<Another embodiment>
The specific structure of the image forming apparatus according to the present invention is not limited to the structure described in the present embodiment, and various modifications are possible.

  The document pressing unit U according to the present embodiment uses two types of members, the elastic sheet member 16 and the elastic attachment member 17, but is a single component in which the elastic sheet member 16 and the elastic attachment member 17 are integrated. It may be formed.

  In the present embodiment, the shape is such that the corner 17a of the elastic mounting member 17 is completely removed, but instead of removing completely, a concave portion may be formed instead to form a thin portion. The same applies to the case where the elastic sheet member 16 and the elastic mounting member 17 are formed as one integrated part. Further, the elastic sheet member 16 and the elastic attachment member 17 may use a rubber member instead of a sponge-like foam member.

  In the present embodiment, the corners 13a of the original pressing sheet 13 are lifted upward by cutting out the corners 17a of the elastic mounting member 17, but the present invention is not limited to this. For example, the original document pressing unit U is constituted by the rectangular original document pressing sheet 13 and the rectangular elastic sheet member 16, and a normal configuration in which notches and recesses are not provided at the corners. Instead, on the attachment surface of the document pressing unit U formed on the back side of the platen cover 12, a spherical surface is formed on the attachment surface at a location corresponding to a corner to lift upward. When the document pressing unit U is attached, the corner 13a is attached so as to be along the spherical surface, so that the corner 13a can be attached with the corner 13a lifted upward.

The perspective view which shows the external appearance structure of the image forming apparatus of the state which closed the pressure plate part The perspective view which shows the external appearance structure of the image forming apparatus of the state which opened the pressure plate part The perspective view which shows the structure of the back surface side of a pressure plate part. Partial sectional view showing the state when the platen is closed The figure which shows the structure of the back side of a document pressing sheet The figure explaining the setting of the size of the original pressing sheet

Explanation of symbols

A body part B pressure plate part S space U document pressing unit 4 image reading unit 4c platen glass 12 platen cover 13 document pressing sheet 13a corner 14 first document scale 15 second document scale 16 elastic sheet member 17 elastic mounting member 17a corner

Claims (3)

An image forming apparatus comprising: a main body having an original placement surface on which an original is placed; and a pressure plate that can be opened and closed with respect to the upper surface of the main body.
A first document scale disposed in the left-right direction on the upper surface on the back side when viewed from the front side of the main body operation;
A second document scale disposed at a right angle to the first document scale on the upper surface on the left side when viewed from the front side of the main body;
A front area of the first original scale, and the original placement surface provided in the right area of the second original scale;
A rectangular document pressing sheet attached to the lower surface side of the pressure plate portion and set in an area narrower than the area of the document placement surface,
Image forming characterized in that at least one of the four corners of the original pressing sheet is attached in a state of being lifted upward, and a gap is formed between the corner and the original placement surface with the pressure plate portion closed. apparatus.   2. The image according to claim 1, wherein an elastic sheet member for attachment is provided on the back side of the original pressing sheet, and the thickness of a portion corresponding to the corner of the elastic sheet member is set to be thinner than the surrounding area. Forming equipment.   3. The image forming apparatus according to claim 1, wherein the at least one corner includes a corner on the right side when viewed from the front side of the operation. 4.

Images