JP4995058B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus and an image forming apparatus, and more particularly to a configuration for preventing contamination of a read image.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a digital copying machine, a printer, or a facsimile machine includes an image forming unit and an image reading device, and the image forming unit forms an image based on image information read by the image reading device. There is something that was made.

  As a reading method of this image reading apparatus, a document as a sheet is placed on a platen glass, and then the original is brought into close contact with the platen glass by a pressure plate, and an image reading unit is scanned in this state (hereinafter referred to as an image reading unit). Is called fixed reading).

  In addition, there is a method of reading an image (hereinafter referred to as “scanning reading”) by fixing an image reading unit below a predetermined image reading position of the platen glass and transporting a document at a constant speed on the image reading position. is there. In such a flow reading, the document that has passed through the image reading position is delivered to a guide member provided on the downstream side of the image reading position, and is then discharged out of the apparatus by a pair of discharge rollers.

  By the way, in such a conventional image reading apparatus, a transported document reading unit that reads a transported document by flow reading and a stationary document reading unit that reads a document placed on a platen glass by fixed reading are separately provided. (See Patent Document 1).

  FIG. 5 is a perspective view of such a conventional image reading apparatus. In FIG. 5, reference numeral 120 denotes a transported document reading unit that reads a transported document by flow reading, and 122 denotes a stationary document reading that is provided separately from the transported document reading unit 120 and reads a document placed on the platen glass 121 by fixed reading. Part. In FIG. 6, reference numeral 125 denotes a pressure plate unit for pressing an original placed on the platen glass 121 against the platen glass 121, and 124 is provided in the pressure plate unit 125. It is a pressing member for pressing to the reading part side.

  When the original image is read by the stationary original reading unit 122, the original is aligned with one end of the platen glass 121 and the original is placed on the platen glass. Then, the pressure plate unit 125 is closed, and then an image (not shown) is displayed. The reading unit is scanned. Also, when reading a document image by flow reading, the image reading unit is moved and fixed in advance below the transported document reading unit 120 before starting the document transport, and then the document is moved over the image reading position. Transport at a constant speed.

JP 2003-46722 A

  By the way, in such a conventional image reading apparatus, when the stationary document reading unit 122 and the transported document reading unit 120 are provided separately, the width of the image reading device becomes wide. Here, in order to narrow the width, for example, one end portion of the platen glass 121 may be used as the transported document reading unit 120 as shown in FIG.

  However, in this case, for fixed reading, a document is set in accordance with one end of the platen glass 121, and then the pressure plate unit 125 is closed. Then, a pressing member 124 that presses the document against the image reading unit side during flow reading Is positioned above the document.

  When the original image is read in this state, if the stationary original is thin or if the range wider than the original width is read, the read image is read in the shade by the pressing member 124 and the read image becomes dirty. The problem of becoming is born.

  Accordingly, the present invention has been made in view of such a current situation, and an object of the present invention is to provide an image reading apparatus and an image forming apparatus that can be reduced in size and prevent smearing of a read image during fixed reading. It is what.

The present invention has a mounting table glass on which a sheet is mounted, and a sheet transport unit that transports the sheet along the mounting table glass, and an openable and closable sheet press for pressing the sheet mounted on the mounting table glass. And an image reading means for reading an image of a sheet placed on the mounting table glass and an image of a sheet conveyed along the mounting table glass by the sheet conveying unit, along the mounting table glass In the image reading apparatus for moving the image reading means to one end portion of the mounting table glass when reading the image of the sheet conveyed, the sheet is provided on one end side of the mounting table glass. and a butting portion which functions as a reference for placing the sheet pressing portion is provided at a position corresponding to one end portion of the mounting table glass, conveyed by the sheet conveying unit sheet A pressing member that presses the sheet in the direction of the image reading means at a position for reading the image of the conveyed sheet, and a bottom surface of the sheet pressing portion at a position corresponding to the pressing member, and the sheet pressing portion When closed, the transparent film member that is in contact with the mounting table glass and is positioned between the sheet transported by the sheet transporting unit and the mounting table glass, and more downstream in the sheet transport direction than the pressing member. And a guide member for guiding a sheet conveyed along the film member after the image is read by the image reading means, and a bottom surface of the sheet pressing portion, and is placed on the mounting table glass. and a sheet pressing member which movement of the sheet regulating together with the film member, provided with, of the film member, to a position for reading an image of a sheet to be conveyed Said image reading means opposed to the portion other than the portion that, a portion for pressing a sheet of the pressing member as white, and the film member, the position corresponding to the vicinity of the abutting portion of one end of the sheet pressing portion Further, the other end is provided on the guide surface of the guide member, and one end of the sheet pressing member is in contact with the other end portion of the film member through the bottom surface of the guide member .

  As in the present invention, the size of the pressing member can be reduced by whitening the portion other than the portion facing the image reading means at the position for reading the image of the document conveyed by the film member and the portion pressing the sheet of the pressing member. In addition, it is possible to prevent smearing of the read image at the time of fixed reading.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a perspective view of an image reading apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view thereof.

  1 and 2, reference numeral 50 denotes an image reading apparatus. The image reading apparatus 50 includes a reading unit 51, a pressure plate unit 1 that is a sheet pressing unit including a document reading and conveying unit 5 that is a sheet conveying unit, and an operation unit. 12 is provided.

  The reading unit 51 includes a platen glass (mounting table glass) 6 for reading a document, and a contact image sensor 16 serving as an image reading unit disposed below the platen glass 6.

  The pressure plate unit 1 is for pressing a document against the platen glass 6 during fixed reading, and is held by a unit main body 52 of the reading unit 51 through a hinge 3 so as to be opened and closed as shown in FIG. . In addition, a sheet pressing member is provided on the bottom surface 1A of the pressure plate unit 1 to bring the document into close contact with the platen glass 6 so as to regulate the movement of the document placed on the platen glass together with a film member 18 to be described later during fixed reading. A certain white ground plate 2 is attached.

  Further, an upper part of the pressure plate unit 1 is provided with a document placing table 4 on which a plurality of documents D1 can be placed. The document placing table 4 is slidable in a width direction orthogonal to the conveying direction of the document D1. A slider 4a is provided. Then, both ends of the document D1 placed on the document placing table 4 can be aligned by the slider 4a.

  As shown in FIG. 4, the contact image sensor 16 emits light from the LED array 16a serving as a light source to the image information surface of the document D1, and the reflected light reflected by the image information surface is detected by the SELFOC lens (trademark) 16b. The image information is read by forming an image on the element 16c.

  The contact image sensor 16 is movable in the left-right direction indicated by the arrow in FIG. 2, and when reading a stationary original image, the original image is scanned by scanning the right side in the figure. Is supposed to read.

  Further, when the original D1 conveyed by the original reading / conveying unit 5 is read by flow reading, the contact image sensor 16 is fixed at the position shown in FIG. 2 and reads the conveyed original D1. ing. Then, the contact type image sensor 16 fixed at the position shown in FIG. 2 and the film member 18 and the pressing member 20 described later constitute a transported document reading unit 40 that reads a document image by flow reading.

  The document reading / conveying unit 5 includes a pickup roller 8 that sends out the document D1 placed on the document placing table 4 and a separation pad 9 that separates the document D1 sent out by the pickup roller 8. Further, a transport roller 13 is provided for transporting the original D1 separated one by one by the separation pad 9 and passing over the fixed contact image sensor 16.

  In FIG. 2, reference numeral 7 denotes a substantially U-shaped document conveyance path (hereinafter referred to as a U-turn path) having the same shape as the arc of the conveyance roller 13. The U-turn path 7 includes a preliminary conveying member 10 that is in contact with the pickup roller 8, a document presence / absence sensor 11 that detects the presence / absence of the document D1, a paper discharge roller 14, and a document that detects the leading edge and the trailing edge of the document D1. An edge sensor 15 and the like are arranged.

  In the pressure plate unit 1 having such a document reading / conveying section 5, when a document image is read by flow reading, if the document D 1 is set on the document table 4 by the operator with the scanned image surface facing upward, the document Presence / absence sensor 11 detects the presence of a document.

  Next, when the operator gives an instruction to start reading from the operation unit 12, the pickup roller 8 rotates, and accordingly, the document D 1 that is in contact with the pickup roller 8 by the preliminary conveying member 10 is moved by the pickup roller 8 and the separation pad 9. Each sheet is separated and transported. Thereafter, the separated document D1 is transported along the U-turn path 7 by the transport roller 13, and further transported to the transport image reading position of the transport document reading unit 40 that reads the image by the contact-type image sensor 16 that is stopped. Is done.

  Thereafter, when the leading edge of the document D1 is detected by the document edge sensor 15, the image information is read by the contact image sensor 16 at the position where the image of the conveyed document is read after being transported by a predetermined amount from that position. Is started.

  Here, at a position corresponding to the contact image sensor 16 of the pressure plate unit 1, a pressing member 20 for pressing the document toward the contact image sensor is provided as shown in FIG. When the image is read by the pressing member 20, the movement of the document D1 in the direction away from the platen glass 6 is restricted, while the contact type image sensor 16 is fixed on the lower side of the platen glass 6 by the transport roller 13. Pass the transport image reading position. At this time, an image is read.

  Then, the document whose image has been read in this way is scooped up by the downstream guide member 19 and heads toward the paper discharge roller pair 14 (see FIG. 2). Thereafter, when the trailing edge of the document D1 is detected by the document edge sensor 15, reading of the image information (flow-reading) by the contact image sensor 16 is finished when a predetermined amount is conveyed from the position.

  Next, the document D1 from which the image has been read is discharged onto the upper surface of the pressure plate unit 1 by the discharge roller pair 14. In the pressure plate unit 1, the above-described reading operation is repeated until the document presence sensor 11 detects that there is no document.

  By the way, between the pressing member 20 and the platen glass 6, as shown in FIG. 4, there is provided a colorless and transparent film member 18 that guides a document conveyed downstream in the sheet conveying direction after an image is read. It has been. By providing the colorless and transparent film member 18, the original on which the image has been read can be transported without being caught to the downstream guide member 19 disposed on the downstream side in the sheet transport direction. When the colorless and transparent film member 18 is provided as described above, the original image is read through the platen glass 6 and the colorless and transparent film member 18.

  Here, in FIG. 4, reference numeral 17 denotes a holding member that holds one end portion of the film member 18, and the holding member 17, the film member 18, and the downstream where the other end portion of the film member 18 is placed on the upper surface. The side guide member 19 is provided in the pressure plate unit 1 as shown in FIG. By configuring in this way, it is possible to form a document transport path for flow reading in the pressure plate unit 1, so that it is not necessary to form a document transport path on the platen glass.

  Thereby, when reading a stationary document, as shown in FIG. 3, the abutting portion 22 a that positions the stationary document D <b> 2 on one end side of the transport image reading position side of the scanner cover 22 to which the platen glass 6 is attached. It can be read by hitting it. That is, as in the present embodiment, by forming the transported document path in the pressure plate unit 1, the reading position of the transported document D1 can be provided within the reading range of the stationary document D2, and the image reading device 50 ( The width of the reading unit 51) can be greatly reduced.

  In addition, the film member 18 is provided in the position corresponding to the one end part of the platen glass 6, as shown in FIG. Specifically, as shown in FIG. 4, the platen glass 6 is disposed along the surface of the platen glass 6, and one end is provided on one side of the platen glass 6, and a document is placed on the platen glass 6. It is located in the vicinity of the abutting portion 22a serving as a reference.

  The other end of the film member 18 guides the conveyed document to a downstream guide member 19 that is a guide member provided downstream of the pressing member 20 in the sheet conveying direction. Surface).

  Here, in FIG. 4, B is a boundary portion where the film member 18 moves away from the surface of the platen glass 6 and moves to the upper surface of the downstream guide member 19, and below this boundary portion B is a downstream guide member. The end portion of the white base plate 2 reaches the lower side of 19. That is, in the present embodiment, one end of the white background plate 2 passes through the bottom surface of the downstream guide member 19 and is in contact with the other end portion of the film member 18.

  Further, the film member 18 is formed of a colorless and transparent film-like member for reading an image of an original through the film member 18, but the reading region A shown in FIG. 4 facing the contact image sensor 16. The surface is white-printed or white-painted except for the part. That is, white printing or white coating is applied to the surface of the film member 18 other than the reading area A, which is the part facing the contact image sensor 16.

  For this reason, the gap C between the holding member 17 and the pressing member 20 and the gap E between the pressing member 20 and the downstream guide member 19 are hidden by the white portion on the surface of the film member 18. In addition, when the white printing or painting of the film member 18 is flow-read, if it is applied to the rubbing surface side of the film member 18 through which the document passes, it may be rubbed and peeled off by the document. For this reason, it is preferable to perform white printing or painting on the surface side facing the platen glass 6.

  Further, the pressing member 20 is formed of a white mold material, so that when the pressing member 20 is viewed from the contact image sensor side, the portion of the pressing member 20 facing the contact image sensor 16 is the film member 18. It appears white through the transparent reading area A.

  For this reason, when reading the stationary document D2 set on the platen glass 6 as shown in FIG. 3, even if the stationary document D2 is a document that easily transmits light, the abutting portion 22a shown in FIG. A white portion is read up to 2. As a result, since the shadows of the gaps C and E are not reflected in the read image, the read image can be prevented from becoming dirty.

  On the other hand, when the stationary document D2 is a document shorter than the length in the width direction orthogonal to the sheet conveyance direction of the reading area A, the outside of the document is read even if the stationary document D2 is a document that does not transmit light. . However, in the present embodiment, the length in the width direction of the pressing member 20 is longer than the length in the width direction of the conveyed sheet.

  Accordingly, also in this case, the shadows of the gaps C and E are hidden by the white portion of the film member 18 from the abutting portion 22a shown in FIG. 4 to the white base plate 2, and also in the transparent reading region A, the pressing member 20 The white part of is read. For this reason, it is possible to prevent the shadows of the gaps C and E from appearing in the read image and becoming dirty.

  With this configuration, even when the stationary document D2 is placed at a position away from the abutting portion 22a, the white portion of the film member 18 extends from the abutting portion 22a to the white background plate 2, and The white of the pressing member 20 is read through the reading area A. For this reason, the read image is also white.

  As described above, in the present embodiment, a portion of the film member 18 other than the reading region A and a portion of the pressing member 20 that presses the film member 18 are opposed to the reading region A of the film member 18. Is white. As a result, as shown in FIG. 4, even when the document placed on the platen glass 6 having one end portion as the transported document reading unit 40 is thin or when reading a range wider than the width of the document, The pressing member 20 or the like is not read in the shade. As a result, the size of the image reading device 50 (reading unit 51) can be reduced, and contamination of the read image at the time of fixed reading can be prevented.

  In particular, in the case of a contact image sensor with an equal magnification optical system that forms an image on a one-to-one basis, since the depth of focus is shallow and the light amount of the light source is small, shadows are more likely to occur than a sensor with a reduction optical system. The configuration of the present invention is effective when an optical contact image sensor is used.

  In the above description, the pressing member 20 is formed of a white mold material, but the present invention is not limited to this. That is, since it is sufficient that the portion of the film member 18 facing the reading area A that presses the film member 18 is white, the surface facing the reading area A may be painted white or a white sheet may be attached. Further, the pressing member 20 may be composed of a white rubber roller or the like.

  Further, the configuration of the image reading apparatus alone has been described so far, but the present invention is not limited to this. For example, it goes without saying that the present invention can also be applied to an image reading apparatus provided in an image forming apparatus including an image forming unit that forms an image by an electrophotographic recording method or an ink jet recording method based on image information read by the image reading device 50. For example, in the case of a copying apparatus using the image reading apparatus 50 according to the present embodiment, the shadows C and E are not formed in the recorded image when copying is performed, so toner and ink are wasted. You can avoid it.

1 is a perspective view of an image reading apparatus according to an embodiment of the present invention. Sectional drawing of the said image reading apparatus. FIG. 3 is a perspective view showing a state where the pressure plate unit of the image reading apparatus is opened. The principal part enlarged view of the said image reading apparatus. The perspective view which shows the conventional image reading apparatus. The perspective view which shows the other conventional image reading apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure plate unit 1A Bottom surface 2 White board 5 Original reading conveyance part 6 Platen glass 16 Contact type image sensor 18 Film member 20 Pressing member 40 Conveyance original reading part 50 Image reading apparatus 51 Reading unit A Reading area

Claims (4)

A mounting table glass on which the sheet is mounted, a sheet transport unit that transports the sheet along the mounting table glass, and an openable and closable sheet pressing unit that presses the sheet mounted on the mounting table glass; Image reading means for reading an image of a sheet placed on the table glass and an image of a sheet conveyed along the table glass by the sheet conveying unit, and conveyed along the table glass In the image reading apparatus that moves the image reading means to one end of the table glass when reading an image of a sheet,
Provided on one end side of the mounting table glass, and a butting portion serving as a reference when the sheet is mounted on the mounting table glass;
The sheet pressing portion is
A pressing member that is provided at a position corresponding to one end of the table glass and presses the sheet conveyed by the sheet conveying unit in the direction of the image reading unit at a position for reading an image of the conveyed sheet;
The sheet and the mounting table, which are provided at a position corresponding to the pressing member on the bottom surface of the sheet pressing unit, abut against the mounting table glass when the sheet pressing unit is closed, and are transported by the sheet transporting unit A transparent film member located between the glass and
A guide member that is provided on the downstream side of the pressing member in the sheet conveying direction and guides the sheet conveyed along the film member after the image is read by the image reading unit;
A sheet pressing member that is provided on the bottom surface of the sheet pressing portion and regulates the movement of the sheet placed on the mounting table glass together with the film member;
The film member has a white portion other than the portion facing the image reading means at a position for reading the image of the conveyed sheet, and the portion of the pressing member that presses the sheet , and the film member has one end The other end is provided on the guide surface of the guide member at a position corresponding to the vicinity of the abutting portion of the sheet pressing portion, and the other end of the sheet pressing member passes through the bottom surface of the guide member. An image reading apparatus that contacts an end .   2. The image reading apparatus according to claim 1, wherein white printing or white coating is applied to a surface of the film member facing the mounting glass. 3. The image reading apparatus according to claim 1, wherein a length of the pressing member in a width direction perpendicular to the sheet conveyance direction is longer than a length of the sheet to be conveyed in the width direction. An image reading apparatus according to any one of claims 1 to 3, the image forming apparatus characterized by comprising a, an image forming unit for forming an image based on image information read by the image reading apparatus .

Images