JP2017034393A - Image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reading device that can improve the quality of an image to be read from a document placed on a document placement surface.SOLUTION: An image forming apparatus 10 comprises: an image reading part that reads an image of a document to be placed on a document placement surface; a cover member 1 that is provided openably/closably with respect to the document placement surface; fixing parts 13 that are provided projecting on a surface 11A of the cover member 1 facing the document placement surface; a sheet-like elastic member that has its corners fixed to the projecting ends of the fixing parts 13 and is brought into contact with a document to be placed on the document placement surface when the cover member 1 is in a closed attitude; and a plurality of projection parts 14 that are provided projecting in an area X1 surrounded by the fixing parts 13 on the opposing surface 11A, and have their projection ends brought into contact with a contact surface of the elastic member with the fixing parts 13 when the cover member 1 is in the closed attitude.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image reading apparatus having a document placement surface.

  In general, an image reading apparatus that reads an image of a document placed on a document placement surface is known (see, for example, Patent Document 1). In this type of image reading apparatus, a cover member provided so as to be openable and closable with respect to the document placement surface is closed, and an image of the document is read. The cover member includes a sheet-like elastic member. When the cover member is closed with respect to the document placement surface, the document placed on the document placement surface is pressed by the elastic member and brought into close contact with the document placement surface.

JP-A-10-285353

  Incidentally, in the above-described image reading apparatus, the elastic member provided on the cover member may have a warp. For example, when the elastic member is formed by cutting a roll-shaped sponge sheet, the elastic member may have a warp. When the elastic member has a warp, a portion of the original pressed by the elastic member does not come into close contact with the original placement surface, and the original is lifted from the original placement surface at the location, and the read image becomes unclear. There is.

  An object of the present invention is to provide an image reading apparatus capable of improving the quality of an image read from a document placed on a document placement surface.

  An image reading apparatus according to the present invention includes an image reading unit, a cover member, a fixing unit, an elastic member, and a plurality of protrusions. The image reading unit reads an image of a document placed on the document placement surface. The cover member is provided to be openable and closable with respect to the document placement surface. The fixing portion protrudes from a surface of the cover member that faces the document placement surface. The elastic member is a sheet-like member that comes into contact with a document placed on the document placing surface when a corner portion is fixed to the protruding end of the fixed portion and the cover member is in a closed posture. The plurality of protrusions protrude in a region surrounded by the fixing portion on the facing surface, and the protruding end contacts the contact surface of the elastic member with the fixing portion when the cover member is in a closed posture. To do.

  According to the present invention, it is possible to improve the quality of an image read from a document placed on a document placement surface.

FIG. 1 is a diagram showing a configuration of an image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of a cover member and an image reading unit of the image forming apparatus according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating the configuration of the cover member of the image forming apparatus according to the first embodiment of the present invention. FIG. 4 is a diagram illustrating the configuration of the cover member of the image forming apparatus according to the first embodiment of the present invention. FIG. 5 is a view showing a modification of the cover member of the image forming apparatus according to the first embodiment of the present invention. FIG. 6 is a diagram showing the configuration of the cover member of the image forming apparatus according to the second embodiment of the present invention. FIG. 7 is a view showing a modification of the protrusion of the image forming apparatus according to the second embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.

[First Embodiment]
First, the schematic configuration of the image forming apparatus 10 according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a schematic cross-sectional view showing the configuration of the image forming apparatus 10. FIG. 2 is a perspective view showing configurations of the cover member 1 and the image reading unit 2. FIG. 2 shows a state in which the cover member 1 is removed from the image reading unit 2.

  The image forming apparatus 10 is a multifunction machine having a plurality of functions such as a facsimile function or a copy function, in addition to a scan function for reading image data from a document and a print function for forming an image based on the image data.

  Specifically, as shown in FIGS. 1 and 2, the image forming apparatus 10 includes a cover member 1, an image reading unit 2, an image forming unit 3, a paper feeding unit 4, and an operation display unit 5. Here, the apparatus including the cover member 1 and the image reading unit 2 is an example of the image reading apparatus according to the present invention. The present invention can be applied to image reading apparatuses such as a scanner apparatus, a facsimile apparatus, and a copier.

  The image forming unit 3 can form an image by electrophotography based on the image data read by the image reading unit 2 or image data input from an information processing apparatus such as an external personal computer. Specifically, the image forming unit 3 includes a photosensitive drum, a charging device, an optical scanning device (LSU), a developing device, a transfer roller, a cleaning device, a fixing roller, a pressure roller, and a paper discharge tray. Then, in the image forming unit 3, an image is formed on the sheet supplied from the paper feeding unit 4, and the sheet after the image formation is discharged to the paper discharge tray. The sheet is a sheet material such as paper, coated paper, postcard, envelope, and OHP sheet.

  The operation display unit 5 includes a display unit such as a liquid crystal display that displays various types of information according to control instructions from a control unit (not shown), and operation keys that input various types of information to the control unit according to user operations. Alternatively, an operation unit such as a touch panel is included.

  The image reading unit 2 can read image data from a document. Specifically, the image reading unit 2 includes a frame 21, a contact glass 22, and a reading unit 23 as shown in FIGS. 1 and 2.

  The frame 21 accommodates the constituent members of the image reading unit 2. A contact glass 22 having translucency is provided on the upper portion of the frame 21. On the upper surface (document placement surface 22A) of the contact glass 22, a document from which image data is read is placed according to the placement reference position 22B. An opening 211 is provided at the upper rear end of the frame 21. The opening 211 is provided with a hinge that supports the cover member 1 to be openable and closable with respect to the document placement surface 22A.

  The reading unit 23 is provided below the contact glass 22 and can be moved in the sub-scanning direction (left-right direction in FIG. 1) by a moving mechanism (not shown) using a driving unit such as a stepping motor. As shown in FIG. 1, the reading unit 23 includes an imaging unit 231.

  The imaging unit 231 is a contact image sensor (CIS) including a light emitting unit and a light receiving unit. The light emitting unit emits light toward the document placed on the document placement surface 22A. When the reading unit 23 is moved by the driving unit, light emitted from the light source toward the document placed on the document placement surface 22A is scanned in the sub-scanning direction. The light receiving unit receives the light emitted from the light emitting unit and reflected by the document, and outputs an electrical signal corresponding to the amount of light received. The image reading unit 2 converts the electric signal output from the light receiving unit into a digital signal by an analog front end circuit (not shown), and acquires image data of the document. The image data of the document read by the image reading unit 2 is output to the control unit. The image reading method by the image reading unit 2 is not limited to the one using a contact image sensor, and may be a method using a CCD.

  The cover member 1 is provided so as to be openable and closable with respect to the document placement surface 22A. For example, the cover member 1 is a flat plate member formed of resin. As shown in FIG. 2, the cover member 1 has a side wall 11 </ b> B that is erected on the peripheral portion of the surface 11 </ b> A that faces the document placement surface 22 </ b> A. A cutout portion 11C is provided at a position corresponding to the opening 211 on the side wall 11B on the rear side of the cover member 1. The cover member 1 is rotatably supported by the hinge attached to the notch 11C. Further, a handle portion 11D is provided at the center portion of the side wall 11B on the front side of the cover member 1. The user can open and close the cover member 1 with respect to the document placement surface 22A by operating the handle portion 11D.

  An elastic member 12 is provided on the facing surface 11A side of the cover member 1 as shown in FIG. The elastic member 12 is a sheet-like member that comes into contact with the document placed on the document placement surface 22A when the cover member 1 is closed with respect to the document placement surface 22A. For example, the elastic member 12 is a sponge sheet in which coated paper is attached to a contact surface 12C with a document. The elastic member 12 has a rectangular shape corresponding to the shape of the document placement surface 22A, has substantially the same area as the document placement surface 22A, and has a predetermined thickness L2 (see FIG. 4). Have. The elastic member 12 is disposed on the facing surface 11A side of the cover member 1 at a position facing the document placement surface 22A when the cover member 1 is in the closed position. When the cover member 1 is closed with respect to the document placement surface 22A, the document placed on the document placement surface 22A is pressed by the elastic member 12 and is brought into close contact with the document placement surface 22A.

  By the way, in the image forming apparatus 10, the contact surface 12B (refer FIG. 4) with the fixing | fixed part 13 mentioned later of the elastic member 12 is curving toward 11 A of opposing surfaces. Specifically, the elastic member 12 is formed by cutting a roll-shaped sponge sheet wound with the contact surface 12C side to which the coated paper is attached facing inward. For this reason, the coated paper has a curved shape at the time of rolling, and the contact surface 12C of the elastic member 12 is warped. For example, in the image forming apparatus 10, the elastic member 12 is disposed such that both ends where the cut member is cut are spaced apart in the left-right direction of the cover member 1, and the contact surface 12 </ b> C is curved with a change in gradient in the left-right direction. ing.

  Here, in the conventional image forming apparatus, when the contact surface 12C of the elastic member 12 is curved toward the facing surface 11A, a portion of the original pressed by the elastic member 12 is not in close contact with the original placement surface 22A. May occur, and the original may be lifted from the original placement surface 22A at the above-mentioned location, and the read image may become unclear. On the other hand, in the image forming apparatus 10 according to the first embodiment of the present invention, as described below, it is possible to improve the quality of an image read from a document placed on the document placement surface 22A. is there.

  Specifically, as shown in FIGS. 3 and 4, the cover member 1 includes a fixing portion 13 and a plurality of protrusions 14. Here, FIG. 3 is a perspective view showing a configuration of the cover member 1 on the facing surface 11A side of the image forming apparatus 10 according to the first embodiment. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3 and shows the cover member 1 in the closed position. FIG. 3 shows the cover member 1 with the elastic member 12 removed. Also, the alternate long and short dash line in FIG. 3 is a boundary line indicating the region X1 surrounded by the fixed portion 13 and the arrangement region X2 of the protruding portion 14. In FIG. 4, the cross section of the cover member 1 and the cross section of the contact glass 22 are hatched. However, for convenience of explanation, the cross section of the elastic member 12 is not hatched.

  The fixing portion 13 protrudes from the facing surface 11A of the cover member 1 facing the document placement surface 22A, and fixes the elastic member 12 to the facing surface 11A side of the cover member 1. Specifically, as shown in FIG. 3, the fixing portion 13 is four pillars that protrude from positions corresponding to the four corners of the document placement surface 22 </ b> A on the facing surface 11 </ b> A. As for the elastic member 12, each corner | angular part 12A shown in FIG.

  Note that the fixed portion 13 may be a plurality of wall bodies that protrude from positions corresponding to both ends of the document placement surface 22A in the front-rear direction or the left-right direction on the facing surface 11A. Further, the fixed portion 13 may be one or a plurality of wall bodies provided corresponding to the peripheral edge portion of the document placement surface 22A on the facing surface 11A.

  When the cover member 1 is in the closed position, the fixing unit 13 presses the elastic member 12 toward the document placement surface 22A by its own weight. When the elastic member 12 is pressed by the fixing portion 13, as shown in FIG. 4, the contact portion with the protruding end 13 </ b> A is elastically deformed.

  The plurality of projecting portions 14 project from the facing surface 11 </ b> A, and the projecting end 14 </ b> A contacts the contact surface 12 </ b> B with the fixing portion 13 of the elastic member 12 when the cover member 1 is in the closed posture. For example, as shown in FIG. 3, the protrusion 14 is a columnar body standing upright in a cylindrical shape on the facing surface 11 </ b> A.

  Specifically, as shown in FIG. 4, the length of the protruding portion 14 in the protruding direction is opposed to a distance L1 between the facing surface 11A and the document placement surface 22A when the cover member 1 is in the closed position. The length exceeds the length obtained by subtracting the thickness L2 of the elastic member 12 interposed between the surface 11A and the document placement surface 22A. Thus, the plurality of protrusions 14 can press the elastic member 12 toward the document placement surface 22A by the weight of the cover member 1 when the cover member 1 is in the closed position. In addition, when the elastic member 12 is pressed by the projection part 14, as shown in FIG. 4, a contact location with 14 A of protrusion ends elastically deforms.

  For example, in the image forming apparatus 10, the length of the protruding portion 14 in the protruding direction exceeds the length of the fixing portion 13 in the protruding direction. As a result, the facing surface 11A of the cover member 1 is undulated due to warpage, sink marks, or the like generated when the cover member 1 is molded, and the placement position of the protrusion 14 on the facing surface 11A is more than the placement position of the fixed portion 13. Even if it floats with respect to 22A, the protruding end 14A of the protruding portion 14 can be brought into contact with the elastic member 12. Further, since the elastic member 12 is elastically deformed at the contact point with the protruding end 14A, the elastic member 12 does not move even if the positions of the protruding ends 14A of the plurality of protruding portions 14 vary in the protruding direction due to the undulation of the opposing surface 11A. The flatness of the contact surface 12C is ensured. The length of the protruding portion 14 in the protruding direction may be the same as the length of the fixing portion 13 in the protruding direction.

  Further, the plurality of protrusions 14 are provided so as to protrude within a region X1 surrounded by the fixing portion 13 on the facing surface 11A. The region X1 is a region including the fixing portion 13 as shown in FIG.

  Specifically, in the image forming apparatus 10, the protrusion 14 is provided in a region where the distance between the facing surface 11A and the contact surface 12B is equal to or less than a predetermined threshold. For example, the threshold value is set based on the measurement result of the curved shape of the contact surface 12B of each elastic member 12. For example, in the image forming apparatus 10, as shown in FIG. 3, an arrangement region X <b> 2 excluding each region including both end portions in the left-right direction from the region X <b> 1 is defined as a region equal to or less than the threshold, and a plurality of protrusions 14 are arranged with a uniform distribution density in the arrangement region X2. Thereby, it becomes possible to arrange the protrusions 14 corresponding to the locations where the contact surface 12C is lifted with respect to the document placement surface 22A, and the number of the protrusions 14 can be arranged while ensuring the flatness of the contact surface 12C. It is possible to reduce.

  In the image forming apparatus 10, the elastic member 12 is arranged with both ends where the cut positions are spaced apart from each other in the front-rear direction of the cover member 1, and the contact surface 12 </ b> C is curved with a change in gradient in the front-rear direction. It may be. In this case, a region excluding each region including both ends in the front-rear direction from the region X1 is defined as a region equal to or less than the threshold value.

  Further, in the image forming apparatus 10, the contact surface 12 </ b> C of the elastic member 12 is not curved toward the facing surface 11 </ b> A of the cover member 1, and the plurality of protrusions 14 are arranged with a uniform distribution density in the region X <b> 1. May be.

  As shown in FIG. 5, the plurality of protrusions 14 face a document of a predetermined size placed on the document placement surface 22A when the cover member 1 is in the closed position on the facing surface 11A. It may be arranged at a predetermined first density in the specific area X5, and may be arranged at a second density lower than the first density outside the specific area X5.

  For example, the specific area X5 is an area facing the A4 size original placed on the original placement surface 22A in a posture in which the longitudinal direction is along the left-right direction in accordance with the placement reference position 22B. Further, the first density and the second density are set based on the curved shape of the elastic member 12, the location and degree of reduction in the quality of the image read from the document placed on the document placement surface 22 </ b> A, and the like. . The specific area X5 is preferably set based on the size of the document that is frequently placed on the document placement surface 22A. As a result, among the documents placed on the document placement surface 22A, it is possible to further improve the degree of adhesion between the document having a predetermined size or less and the document placement surface 22.

  The plurality of protrusions 14 are predetermined in a specific area X5 facing a document of a predetermined size placed on the document placement surface 22A when the cover member 1 is in the closed posture on the facing surface 11A. It may be arranged so as to project by the first distance, and project by a second distance shorter than the first distance outside the specific region X5.

  For example, the second distance is the same as the length of the fixed portion 13 in the protruding direction. Also in this case, among the documents placed on the document placement surface 22A, it is possible to further improve the degree of close contact with the document placement surface 22 for a document having a predetermined size or less. .

  As described above, in the image forming apparatus 10, the plurality of projecting portions 14 are provided in the region X <b> 1 surrounded by the fixing portion 13 on the facing surface 11 </ b> A of the cover member 1. As a result, when the cover member 1 is in the closed position, the elastic member 12 is pressed against the protrusion 14 and is brought into close contact with the document placement surface 22A. Therefore, it is possible to improve the quality of the image read from the document placed on the document placement surface 22A.

[Second Embodiment]
The image forming apparatus 10 according to the second embodiment of the present invention will be described below with reference to FIG. In the second embodiment, when the cover member 1 shown in FIG. 3 is in the closed posture, the facing surface 11A undulates with respect to the document placement surface 22A and the length of the protruding portion 14 in the protruding direction is the same. This is different from the first embodiment described above. The configuration of the other parts is the same between the second embodiment and the first embodiment described above. Therefore, in the following description, in the second embodiment, components that are the same as those in the first embodiment described above are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof is omitted.

  Here, FIG. 6 is a schematic cross-sectional view of the cover portion 1 of the image forming apparatus 10 according to the second embodiment at the position IV-IV shown in FIG. 3, and the cover member 1 is placed on the document placement surface 22A. The cover member 1 in the case of the open attitude | position opened with respect to is shown. In FIG. 6, the cover member 1 with the elastic member 12 removed is shown. 6 indicates a plane X4 including the reference surface X3 parallel to the document placement surface 22A and the protruding ends 14A of the plurality of protrusions 14 when the cover member 1 is in the closed position. . Moreover, in FIG. 6, the cross section of the cover member 1 is not hatched for convenience of explanation.

  Specifically, in the image forming apparatus 10 according to the second embodiment, as shown in FIG. 6, the facing surface 11A of the cover unit 1 is on a reference surface X3 parallel to the document placement surface 22A in the closed posture. It is undulating. For example, the facing surface 11 </ b> A of the cover member 1 is curved toward the elastic member 12 side by changing the gradient in the left-right direction due to warpage occurring in the molding process. Note that the facing surface 11A of the cover member 1 may be curved by changing the gradient in the front-rear direction. Moreover, 11 A of opposing surfaces of the cover member 1 may be curving toward the opposite side to the elastic member 12 side. Further, the facing surface 11A of the cover member 1 may be undulated with respect to the reference surface X3 due to sink marks or the like generated in the molding process.

  Here, in the image forming apparatus 10 according to the second embodiment, the length in the protruding direction of each of the plurality of protruding portions 14 is determined so that the plane X4 including each protruding end 14A is parallel to the reference plane X3. ing. For example, as shown in FIG. 6, in the configuration in which the protrusions 14 are arranged at equal intervals on the curved vertex of the facing surface 11A and on both sides in the left-right direction, the length in the protrusion direction of each of the plurality of protrusions 14 is as follows. It is determined as follows. That is, the length in the projecting direction of the left and right projecting portions 14 is greater than the distance in the projecting direction of the central projecting portion 14 from the reference surface X3 in the arrangement position of the projecting portion 14 in the center of the facing surface 11A. The distance L3 is increased by the difference between the distance L4 between the distance L3 and the reference surface X3 at the positions where the protrusions 14 on the left and right sides of the facing surface 11A are disposed.

  For example, the length in the protruding direction of each of the plurality of protrusions 14 is set based on the measurement result of the curved shape of the facing surface 11A of each cover member 1. As a result, the facing surface 11A of the cover member 1 is undulated due to warpage or sink marks generated during molding, and the placement position of the protrusion 14 on the facing surface 11A is closer to the document placement surface 22A than the placement position of the fixed portion 13. Even if it is a case where it floats up, it is possible to make the protrusion end 14A of the protrusion part 14 contact the elastic member 12. FIG.

  In addition, as shown in FIG. 7, the protrusion part 14 may have the rib 14C formed in the circumference | surroundings of the cylindrical part 14B standingly arranged in 11 A of opposing surfaces, and the cylindrical part 14B. The rib 14C suppresses a change in shape when the cylindrical portion 14B is molded.

1: Cover member 2: Image reading unit 3: Image forming unit 4: Paper feeding unit 5: Operation display unit 10: Image forming device 11 A: Opposing surface 12: Elastic member 13: Fixing unit 14: Protruding unit 22 A: Document placement Surface 23: reading unit

Claims (8)

An image reading unit for reading an image of a document placed on the document placement surface;
A cover member provided to be openable and closable with respect to the document placement surface;
A fixing portion projecting from the surface of the cover member facing the document placement surface;
A sheet-like elastic member that is in contact with a document placed on the document placement surface when a corner is fixed to the protruding end of the fixed portion and the cover member is in a closed posture;
A plurality of protrusions protruding in a region surrounded by the fixing portion on the facing surface, and a protruding end contacting a contact surface of the elastic member with the fixing portion when the cover member is in a closed posture;
An image reading apparatus comprising:   The length of the protrusion in the protruding direction is such that the distance between the facing surface and the document placement surface is between the facing surface and the document placement surface when the cover member is in the closed position. The image reading apparatus according to claim 1, wherein the length exceeds a length obtained by subtracting a thickness of the interposed elastic member. The elastic member has the contact surface curved toward the facing surface,
The image reading apparatus according to claim 1, wherein the protrusion is provided in a region where a distance between the opposing surface and the contact surface is equal to or less than a predetermined threshold value. The facing surface is undulated with respect to a reference surface parallel to the document placement surface in the closed posture,
The image reading apparatus according to claim 1, wherein a length of each of the plurality of protrusions in a protruding direction is determined such that a plane including each protruding end is parallel to the reference surface.   The image reading apparatus according to claim 1, wherein a length of the protruding portion in the protruding direction exceeds a length of the fixing portion in the protruding direction.   The protrusion has a predetermined first density in a specific area facing a document of a predetermined size placed on the document placement surface when the cover member is in the closed posture on the facing surface. The image reading apparatus according to claim 1, wherein the image reading apparatus is arranged at a second density lower than the first density outside the specific area.   The protrusion has a predetermined first distance in a specific area facing a document of a predetermined size placed on the document placement surface when the cover member is in the closed position on the facing surface. 3. The image reading apparatus according to claim 1, wherein the image reading apparatus is disposed so as to protrude only by a distance that is shorter than the first distance by a distance that is shorter than the first distance.   The image reading apparatus according to claim 1, wherein the image reading unit includes a contact image sensor.

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