Image reading device and image forming device

Abstract

To prevent bending of an upstream guide and a downstream guide in a case of configuration in which the upstream guide and the downstream guide are provided with an image reading unit therebetween.SOLUTION: A conveying frame is provided with an upstream guide 410 on an upstream side in a document conveyance direction and a downstream guide 420 on a downstream side with an enclosed module M therebetween. The upstream guide 410 and the downstream guide 420 are supported by the conveying frame on both end sides in a width direction of a document D intersecting with the document conveyance direction. A connection stay 600 bridged over the enclosed module M connects the upstream guide 410 with the downstream guide 420. With this, even when an image of a small-sized document D is read with configuration in which the enclosed module M having therein a second image reading unit 201 is arranged between an upstream roller 8 and a downstream roller 9, the upstream guide 410 and the downstream guide 420 are hardly bent, and thus accuracy in reading the image of the small-sized document D can be improved.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an image reading device that reads an image from a sheet such as a document, and an image forming apparatus equipped with the same. [Background technology]

[0002] Conventionally, image reading devices used in image forming devices such as scanners, printers, and copiers read images formed on documents while the documents are transported by an ADF (Auto Document Feeder), which is a document transport device. In order to read the images on the documents, the ADF is provided with an image reading unit (Patent Document 1).

[0003] In addition, in the ADF, an upstream roller is provided on the upstream side and a downstream roller is provided on the downstream side of the image reading unit in the document transport direction in order to transport the document. These upstream rollers and downstream rollers are rotatably supported by a housing. The housing is formed with an upstream guide section that guides the document transported by the upstream roller to the image reading unit, and a downstream guide section that guides the document that has passed through the image reading unit. In addition, reinforcing ribs are formed between the upstream guide section and the image reading unit, and between the image reading unit and the downstream guide section in the document transport direction to reinforce the upstream guide section and the downstream guide section, respectively. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-64153 A Summary of the Invention [Problem to be solved by the invention]

[0005] Recently, it is desired to read images from small-sized documents (sheets), such as business cards. In order to transport small-sized documents, the distance between the upstream roller and the downstream roller arranged on either side of the image reading unit in the document transport direction is narrowed, and accordingly, the upstream guide unit and the downstream guide unit are formed small by shortening their transport direction lengths. In this case, it becomes difficult to form reinforcing ribs between the upstream guide unit and the image reading unit and between the image reading unit and the downstream guide unit, so the rigidity of the upstream guide unit and the downstream guide unit decreases. As a result, the upstream guide unit and the downstream guide unit are likely to bend during the transport of the document. If the upstream guide unit and the downstream guide unit formed in the housing are bent, the positions of the upstream roller and the downstream roller supported by the housing through the housing will change, and there is a risk that the reading accuracy of the image of the document will decrease.

[0006] SUMMARY OF THE PRESENT DISCLOSURE The present invention has been made in view of the above problems, and has an object to provide an image reading device and an image forming device that improve the accuracy of reading an image on a document. [Means for solving the problem]

[0007] The present invention One embodiment of the present invention The image reading device according to the present invention is but Delivery Forming a sheet transport path do Transparent Materials and, an opposing member disposed opposite the transparent member and forming the sheet transport path together with the transparent member; before Note An image of the sheet being conveyed along the sheet conveying path , through the transparent member an image reading unit for reading the image; a storage member including the transparent member and storing the image reading unit; a biasing unit for biasing the storage member toward the opposing member; and The image reading unit On Stream side and arranged adjacent to the storage member. a first guide portion that forms the sheet transport path along which the sheet is transported toward the image reading portion; In the conveying direction The image reading unit Under Stream side and arranged adjacent to the storage member. a second guide portion that forms the sheet transport path along which the sheet that has passed through the image reading portion is transported; and a second guide portion that is disposed on the opposite side of the sheet transport path as viewed in a width direction of the sheet that is perpendicular to the transport direction and that is parallel to the image reading portion. and the storage memberand a connecting member that spans between the first guide portion and the second guide portion and connects the first guide portion and the second guide portion. Effect of the Invention

[0008] According to the present invention, the accuracy of reading an image on a sheet can be improved even in the case of a small-sized sheet. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an image forming apparatus according to an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. 2 is an enlarged cross-sectional view showing a part of the image reading device. [Figure 4] FIG. 4 is a diagram for explaining a hinge mechanism. [Diagram 5] (a) Diagram of CIS, (b) partial oblique view of CIS. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The image reading device and image forming device according to the present embodiment will be described below with reference to the drawings. The image forming device according to the present embodiment can be configured as a copier, a facsimile, a printer, or a combination machine thereof, and includes an image reading device having a scanner unit and an ADF capable of feeding an original (sheet-shaped original) to the image reading unit of the scanner unit. This image reading device is suitable for use in image forming devices such as copiers and facsimiles, as well as in cases where it is configured as a standalone device such as a flatbed scanner equipped with an ADF (Auto Document Feeder). It should be noted that the dimensions, materials, shapes, and relative positions of the components described in the following embodiments are not intended to limit the scope of the present invention to those alone, unless otherwise specified.

[0011] [Image forming equipment] First, the schematic configuration of an image forming apparatus according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view showing an image forming apparatus 101. In the following, the position where a user faces an operation unit (not shown) where various inputs / settings are made to the image forming apparatus will be referred to as the "front side" of the image forming apparatus, and the rear side will be referred to as the "rear side." In other words, FIG. 1 shows the internal configuration of the image forming apparatus as seen from the front side. In each drawing, the same parts and portions are given the same reference numerals, and duplicated explanations will be omitted.

[0012] 1, the image forming apparatus 101 includes an image forming apparatus main body 101A and an image reading device 103 provided on the upper part of the image forming apparatus main body 101A. The image reading device 103 includes a scanner unit (image reading apparatus main body) 30 and an ADF 1 (sheet conveying means) provided on the scanner unit 30. The image forming apparatus 101 further includes a control unit 132 having a CPU, RAM, ROM, etc., for controlling the image reading device 103 and the image forming apparatus main body 101A, etc.

[0013] The ADF 1 is configured to automatically feed documents D (sheets) loaded on the document feed tray 2 by a user to the scanner unit 30. The scanner unit 30 is configured to receive reflected light of light irradiated on the document D being conveyed at an image reading position, optically read the document D, convert it into an electrical signal, and create image data (image read information) based on the electrical signal. Details of the ADF 1 and the scanner unit 30 will be described later.

[0014] The image forming apparatus main body 101A has an image forming section 133 that forms an image on a sheet P, and a sheet feeding section 34 that feeds the sheet P to the image forming section 133. The sheet feeding section 34 has sheet stacking sections 137a, 137b, 137c, and 137d on which sheets are stacked, a feeding roller 32 that feeds the sheets P in the sheet stacking sections 137a to 137d, and a conveying roller 33a and a separating roller 33b that separate and convey the sheets P one by one. Furthermore, the image forming apparatus main body 101A has a discharge roller 40 that discharges the sheet P on which the image has been formed to the outside (outside the machine) of the image forming apparatus main body 101A, and a sheet discharge receiving section (tray) 130 on which the discharged sheet P is stacked. The image forming apparatus main body 101A is configured to form a copy image on the sheet P by the image forming section 133 based on image data.

[0015] The image forming section 133 has a photosensitive drum 121, and a charger 118, a developing unit 124, a transfer charger 125, and a separation charger 126 arranged around the photosensitive drum 121. In the image forming apparatus main body 101A, an exposure unit 123 is operated based on an electric signal or image data of an image of an original D to form an electrostatic latent image on the surface of the rotating photosensitive drum 121. The electrostatic latent image is developed (toner is supplied) by the developing unit 124 to become a toner image. The image forming section 133 and the fixing unit 129 constitute an image forming means that forms an image on a sheet P, which is a sheet separate from the original D, based on image information read from the original D by the image reading device 103.

[0016] At the bottom of the image forming apparatus main body 101A, sheet stacking units 137a, 137b, 137c, and 137d are arranged, in which sheets P of various sizes are loaded. Each of the sheets P stored in the sheet stacking units 137a to 137d is fed out one by one by the corresponding feed roller 32, and delivered to the corresponding conveyance roller 33a and separation roller 33b. The sheet P is also fed from the manual feed tray 137e by the separation feed roller 138.

[0017] A sheet P fed from any one of the sheet stacking units 137a to 137d or the manual feed tray 137e is conveyed to the registration rollers 136 via the corresponding conveying rollers 131. Then, the sheet P has its skew corrected (skew correction) by the registration rollers 136, and is aligned with the toner image on the photosensitive drum 121, and is supplied between the photosensitive drum 121 and the transfer charger 125. The toner image on the photosensitive drum is transferred to the sheet P by the transfer charger 125, and the sheet P is separated from the photosensitive drum 121 by the separation charger 126. A cleaner 127 cleans the surface of the photosensitive drum 121 to which the toner image has been transferred. Then, the charger 118 charges the surface of the photosensitive drum 121 in preparation for the next exposure.

[0018] The sheet P onto which the toner image has been transferred is conveyed by a belt conveying unit 128 to a fixing unit 129, where the sheet P is heated and pressurized to fix the toner image onto the surface. Then, the sheet P onto which the toner image has been fixed is discharged via discharge rollers 40 to a sheet discharge receiving unit 130.

[0019] [Image reader] Next, the ADF 1 and the scanner unit 30 according to this embodiment will be described with reference to Figs. 2 to 4. As described above, the image reading device 103 is composed of the scanner unit 30, which is an example of a main body, and the ADF 1 configured to be freely opened and closed with respect to the scanner unit 30. That is, in this image reading device 103, the ADF 1 is rotatably supported by the scanner unit 30 by a hinge mechanism 11 (see Fig. 4) disposed at the back side so that the document table glass 213 can be opened and closed from the front side. The image reading device 103 is provided with a first image reading unit 151 and a second image reading unit 201 at two locations facing the document transport path H, and adopts a dual scan method in which an image of the front side (first side D1: Fig. 3) of the document D is read and an image of the back side (second side D2: Fig. 3) is also read.

[0020] As shown in Fig. 3, the ADF 1 is configured to automatically feed an original D to a first image reading position R1 by the first image reading unit 151 and a second image reading position R2 by the second image reading unit 201. The ADF 1 includes an original feeding unit 23 that extends in an elongated shape along the width direction (direction perpendicular to the original conveying direction) of the original D. As shown in Fig. 2, an original feeding roller 4, a separation roller 5, a retard roller 6, a registration roller 7, an upstream roller 8 (first conveying roller), a downstream roller 9 (second conveying roller), and a discharge roller 10 are arranged in the original feeding unit 23 as a conveying means.

[0021] The document feed roller 4 is supported so as to be movable from the dashed line position to the solid line position in Fig. 2 so as to feed the documents D loaded on the document feed tray 2. The separation roller 5 and the retard roller 6 separate the documents D fed out from the document feed tray 2 by the document feed roller 4 into individual sheets. The registration roller 7 is disposed downstream of the separation roller 5 and the retard roller 6 in the transport direction of the documents D and corrects (corrects) skew of the documents D. The discharge roller 10 is disposed downstream of the downstream roller 9 and discharges the documents D after image reading to the document discharge section 3 as a discharge tray. The document feed tray 2, on which the documents D are loaded before image reading, is attached in a cantilevered state at an upper position on one end side (the right end side in Fig. 2) of the automatic document transport section so as to protrude substantially horizontally.

[0022] The scanner unit 30 has a first flow reading glass (platen glass) 152 as a first transparent member, and a document table glass 213 arranged side by side with the first flow reading glass 152 in the sub-scanning direction (left and right direction in FIG. 2). As shown in FIG. 3, the first image reading unit 151 is configured to read an image of a first side D1 of a document D conveyed through a document conveying path H as a sheet conveying path through the first flow reading glass 152. In this embodiment, the first image reading unit 151 is arranged upstream of the second image reading unit 201 in the document conveying direction. That is, the second image reading unit 201 is arranged downstream of the first image reading unit 151 in the document conveying direction (arrow F direction). The second image reading unit 201 is also arranged on the opposite side of the first image reading unit 151 across the document conveying path H. The second image reading section 201 is configured to read an image on a second side D2 of an original D conveyed through an original conveying path H through a second flow reading glass 202 serving as a second transparent member.

[0023] The first image reading unit 151 as another image reading unit uses, for example, a CIS (Contact Image Sensor) which is a contact type image sensor with a unit-magnification optical system. This CIS irradiates light from an LED array (not shown) as a light source onto the image information surface of the document D, and the reflected light reflected from the image information surface is imaged on a sensor element (photoelectric conversion element 15: see Fig. 5(a) and Fig. 5(b) described later) to read image information. The second image reading unit 201 as an image reading unit also uses a CIS like the first image reading unit 151. The first image reading unit 151 and the second image reading unit 201 in this embodiment are configured to focus the reading optical system on the read image surface of the document D conveyed via the first flow reading glass 152 and the second flow reading glass 202, respectively.

[0024] The first image reading unit 151 is connected to a drive belt (not shown). The first image reading unit 151 is configured to be movable between a flow reading position P2 below the first flow reading glass 152, a position P1, and a terminal position P3 below the document table glass 213 by being driven by a drive motor M4 provided in the scanner unit 30 under the control of the control unit 132. The flow reading position P2 is the above-mentioned first image reading position R1. The first image reading unit 151 is configured to read an image of a first side D1 of the document D conveyed through the document conveying path H through the first flow reading glass 152 at the flow reading position P2 (first image reading position R1). The position of the first image reading unit 151 can be grasped by the control unit 132 based on a position sensor (not shown) and the number of rotation pulses of the drive motor M4.

[0025] In this embodiment, a mode in which the first image reading unit 151 is stopped at the flow reading position P2 and the original D is moved on the first flow reading glass 152 by the ADF 1 to read the image is referred to as "flow reading". Also, a mode in which the original D is placed on the original platen glass 213 and the image is read while the first image reading unit 151 is moved in the left-right direction in FIG. 3 between the position P1 and the terminal position P3 is referred to as "fixed reading".

[0026] The ADF 1 has a document feed tray 2, a document feed section 23, and a document discharge section 3. The document feed tray 2 is capable of loading a document D for skim reading. When skim reading, the document feed section 23 sends the document D to a predetermined image reading position (skim reading position P2, first image reading position R1) via the document transport path H. The document D that has been skim read is discharged and loaded on the document discharge section 3. The ADF 1 is also configured to be able to press the document D with a resin plate (not shown) so that the document D placed on the document table glass 213 does not move when fixed reading is performed.

[0027] The document discharge section 3 disposed below the document feed tray 2 receives the document D whose image has been read at the first image reading position R1 and the second image reading position R2 and which is sent out from the document feed section 23. At each of the image reading positions R1 and R2, a first flow reading glass 152 and a second flow reading glass 202, which are transparent and guide the document D, are disposed so as to sandwich the document transport path H between them. The document discharge section 3 is attached so as to protrude substantially horizontally from a lower position on one end face side of the automatic document transport section, and is configured so that the documents D discharged on the upper surface side of the document discharge section 3 are stacked in a layered manner. The document feed tray 2 and the document discharge section 3 are disposed so as to face each other vertically with an appropriate interval therebetween, and are disposed in an overlapping arrangement in which they are substantially overlapping in a plan view.

[0028] [Image reading position] Next, with reference to FIG. 2, a case will be described in which the ADF 1 conveys the original D to the first image reading unit 151 and the second image reading unit 201, and the first side D1 and the second side D2 of the original D are successively read.

[0029] 2, a plurality of documents D are stacked on the document feed tray 2, and after the user selects a reading mode, the control unit 132 (see FIG. 1) makes a judgment based on the detection of the presence or absence of the document D by the document detection sensor S1 located upstream of the document feed roller 4. When the control unit 132 judges that the document D is detected, the first image reading unit 151 at position P1 of the scanner unit 30 is guided by a shaft unit (not shown) while being loaded on a carriage C supported so as to be able to swing, and is moved toward a running reading position P2.

[0030] Thereafter, the document feed roller 4 is lowered from the broken line position to the solid line position in FIG. 2 under the control of the control unit 132, and the document D is sent into the entrance-side transport path space to the document feed unit 23. Then, the document D transported by the rotational driving force of the document feed roller 4 to the separation roller 5 in the document feed unit 23 is separated into individual sheets by the frictional force between the separation roller 5 and the retard roller 6 spring-loaded from below. The separated document D has its leading edge abutted against the registration roller 7, whose rotation is stopped. When the registration roller 7 is rotated by the drive motor Mo under the control of the control unit 132, the leading edge of the document D transported by the registration roller 7 is detected as follows. That is, it is detected by a flag (not shown) of the document detection sensor S2 installed upstream of the registration roller 7 in the document transport direction (arrow F direction: see FIG. 3).

[0031] 2 is operated under the control of the control unit 132, the electromagnetic clutch CL connected between the drive motor Mo and the registration roller 7 is operated to cut off the drive transmission to stop the rotation of the registration roller 7 for a certain period of time. Since the original D continues to be transported by the separation roller 5 while the registration roller 7 is stopped, a loop is formed in the original D and the skew is removed (skew correction). As shown in FIG. 2, the drive motor Mo operated under the control of the control unit 132 rotates the separation roller 5, the upstream roller 8, the downstream roller 9, and the discharge roller 10. The drive motor Mo rotates the original feed roller 4 via the separation roller 5, and rotates the registration roller 7 via the electromagnetic clutch CL.

[0032] An original detection sensor S3 is disposed between the registration roller 7 and the upstream roller 8 in the original feeding section 23. A first image reading position R1 and a second image reading position R2 are provided in the transport path between the upstream roller 8 and the downstream roller 9 (see FIG. 3). As described above, the first image reading position R1 is a position where the first image reading section 151 of the scanner section 30 reads the first side D1 of the original D, and the second image reading position R2 is a position where the second image reading section 201 of the ADF 1 reads the second side D2 of the original D (see FIG. 3).

[0033] The document D that has been subjected to skew correction is transported to the upstream rollers 8 by the registration rollers 7. The control unit 132 aligns the reading timing of the leading edge of the document D with the first image reading position R1 based on the detection by the document detection sensor S3, and controls the driving of the upstream rollers 8 to send the document D to the first image reading position R1. The document D is transported by the downstream rollers 9 while the images on both sides of the document D are read at the first image reading position R1 and the second image reading position R2, and then the document D is sequentially discharged by the discharge rollers 10 onto the stacking surface of the document discharge unit 3 and stacked.

[0034] The document D is sandwiched and transported by the upstream rollers 8, and is further sandwiched and transported by the downstream rollers 9. The upstream rollers 8 are disposed on the upstream side of the document transport direction (arrow F direction: see FIG. 3) in the document transport path H, and transport the document D to the first image reading unit 151 and the second image reading unit 201. The downstream rollers 9 are disposed on the downstream side of the document transport direction in the document transport path H, and transport the document D that has passed through the first image reading unit 151 and the second image reading unit 201. The upstream rollers 8 transport the document D in a diagonally downward direction, and the downstream rollers 9 transport the document D in a diagonally upward direction. In this embodiment, the upstream rollers 8 and the downstream rollers 9 are rotatably supported by a transport frame 400 (see FIG. 7 described later) serving as a housing.

[0035] In this embodiment, when the sheet conveying speed by the upstream rollers 8 is "V1" and the sheet conveying speed by the downstream rollers 9 is "V2", the speeds are set to satisfy the relationship "V1≦V2". This setting is based on the control of the drive motor Mo (see FIG. 2) by the control unit 132 (see FIG. 1), the setting of the gear ratio of a transmission mechanism (not shown) that transmits the drive of the drive motor Mo to rotate the upstream rollers 8 and the downstream rollers 9, and the like.

[0036] Incidentally, when reading the original D with the pressure plate section (the part of the original table glass 213) of the scanner section 30, the ADF 1 is rotated via the hinge mechanism 11 (see FIG. 4) to be opened from the scanner section 30 and positioned above the original table glass 213. Thereafter, when the ADF 1 is closed toward the scanner section 30 and the user performs a copying operation, the first image reading section 151 waiting at position P1 is guided to the shaft section (not shown) while being loaded on the carriage C that is supported to swing. Then, the first image reading section 151 moves to the terminal position P3 while reading the image. As a result, the image of the original D on the original table glass 213 is read by the first image reading section 151.

[0037] [Hinge mechanism] Here, the hinge mechanism 11 will be described with reference to Fig. 4. As shown in Fig. 4, the hinge mechanism 11 connects the ADF 1 and the scanner unit 30 at the rear side of the image reading device 103, and supports the ADF 1 so that it can rotate in the direction of the arrow E relative to the scanner unit 30 around the rotation shaft 12. This allows the ADF 1 to be opened and closed relative to the document table glass 213 (see Fig. 2) on the scanner unit 30 side. The hinge mechanism 11 is also attached so as to be movable in the direction of the arrow I (up and down) relative to the scanner unit 30, and is configured to be able to handle the reading of a thick document D.

[0038] [ADF and image reader configuration] Next, the configuration of the ADF 1 and the reading section of the scanner unit 30 in the vicinity thereof will be described with reference to FIGS.

[0039] 3, the second image reading unit 201 is configured so that foreign matter generated during transport of an original in the original feeding unit 23 including the original transport path H does not enter the reading portion of the second image reading unit 201 or the rear surface of the second running reading glass 202. To achieve this, the second image reading unit 201 is housed in a sealed module M sealed by a sealed guide 250 and the second running reading glass 202. The sealed guide 250 and the second running reading glass 202 are fixed with, for example, an adhesive to fill the gap between them.

[0040] A signal line cable from the second image reading unit 201 is connected to an image processing unit (not shown) provided in the image forming apparatus 101 through an opening (not shown) provided in a part of the sealed guide 250. The periphery of this opening is covered with a sponge-like elastic member so as to surround the signal cable, preventing the intrusion of foreign matter such as paper dust.

[0041] A compressed compression spring 203 for pressing the second image reading unit 201 against the second flow reading glass 202 is provided inside the sealed guide 250. The second image reading unit 201 abuts against the rear side of the second flow reading glass 202 via a spacer (not shown). The sealed module M is urged toward the document transport path H by a plurality of compression springs 110 as urging means having one end connected to a connecting stay 600 (see FIG. 6 described later) in the ADF 1.

[0042] Here, a protrusion is provided on a part of the sealed guide 250 or on a part of the transport frame 400 (see FIG. 7), and this protrusion is abutted against the first flow reading glass 152 to ensure a gap in the document transport path H formed by the first flow reading glass 152 and the second flow reading glass 202. Also, as shown in FIG. 3, a white sheet member 212 is provided above the second flow reading glass 202 to prevent show-through of thin paper when the first image reading unit 151 reads the front side of the document D.

[0043] In addition, the transport frame 400 (see FIG. 7) is provided with an upstream guide 410 as a first guide section on the upstream side in the document transport direction and a downstream guide 420 as a second guide section on the downstream side in the document transport direction, with the sealed module M sandwiched between them. The upstream guide 410 is provided upstream of the second image reading unit 201, and forms a sheet transport path that transports the document D passing through the upstream roller 8 diagonally upward while holding it toward the scanner unit 30 side across the width direction. On the other hand, the downstream guide 420 is provided downstream of the second image reading unit 201, and forms a sheet transport path that transports the document D passing through the gap of the document transport path H formed by the first running reading glass 152 and the second running reading glass 202 diagonally downward while holding it toward the scanner unit 30 side. In this embodiment, the upstream guide 410 and the downstream guide 420 are integrally formed with the transport frame 400 so as to be supported at both ends in the width direction.

[0044] When reading the original D as described above, the first image reading unit 151 provided in the scanner unit 30 is moved to a first image reading position R1 (see FIG. 3) under the control of the control unit 132. The second image reading unit 201 provided in the ADF 1 reads an image at a second image reading position R2 (see FIG. 3). The distance L (see FIG. 3) between the first image reading position R1 and the second image reading position R2 is determined as an appropriate distance that is not affected by the illumination (not shown) provided in each image reading unit 151, 201. In this embodiment, for example, it is set to "L=15.5 mm".

[0045] The first image reading unit 151 and the second image reading unit 201 are disposed to face each other across the document transport path H. A first flow reading glass 152 is disposed between the first image reading unit 151 and the document transport path H, and a second flow reading glass 202 is disposed between the second image reading unit 201 and the document transport path H. The first flow reading glass 152 and the second flow reading glass 202 can each be formed of a plate-like glass.

[0046] In the document transport path H, a transport guide 500 is disposed adjacent to the first running reading glass 152 and partially inclined in the document transport direction. The transport guide 500 and the second running reading glass 202 are disposed facing each other with a gap therebetween. The first running reading glass 152 and the upstream guide 410, and the first running reading glass 152 and the downstream guide 420 are disposed facing each other with a gap therebetween. The image of the document D is read while being transported through the gap formed by the first running reading glass 152 and the upstream guide 410, and the gap formed by the second running reading glass 202, the downstream guide 420, and the transport guide 500. The gap between the first running reading glass 152 and the second running reading glass 202 is set to, for example, 0.6 mm.

[0047] The first image reading unit 151 is pressed toward the first flow reading glass 152 by a compression spring 153 provided in the carriage C. Spacers (not shown) attached to both ends of the first image reading unit 151 come into contact with the first flow reading glass 152, thereby ensuring an appropriate focal distance with respect to the first surface D1 of the document D passing through the document transport path H.

[0048] On the other hand, the second image reading unit 201 is pressed toward the second flow reading glass 202 by a compression spring 203 arranged inside the sealed module M. Spacers (not shown) attached to both ends of the second image reading unit 201 come into contact with the second flow reading glass 202, thereby ensuring an appropriate focal distance with the second surface D2 (see FIG. 3) of the document D passing through the document transport path H.

[0049] [CIS used in the first and second image reading units] Here, the structure of the CIS 35 used in the above-mentioned first image reading unit 151 and second image reading unit 201 will be described with reference to Figs. 5(a) and 5(b). In this embodiment, the CIS 35 is used as an example of an image reading unit. As shown in Fig. 5(a), the CIS 35 has a frame 18, and an illumination device composed of a light source (not shown) using an LED that irradiates light onto the document D and a light guide 13 is attached to the frame 18. The light guide 13 takes in light emitted from the light source and emits the light so that the amount of irradiation light is approximately uniform over the length of the document reading area in the main scanning direction.

[0050] Furthermore, a sensor board 16 on which a sensor array is mounted, and a lens array 17 for forming an optical image of the original D on the sensor array are arranged on the frame 18. The sensor array is formed by arranging photoelectric conversion elements 15, each having a plurality of light receiving parts for photoelectrically converting an optical image 14 (see FIG. 5(b)) of the original D into an electric signal, in a line in the main scanning direction. As shown in FIG. 5(b), the sensor board 16, the lens array 17, etc. are arranged along the main scanning direction related to image formation by the image forming unit 133 (see FIG. 1).

[0051] Here, the image reading area of ​​the original D by the CIS 35 indicates the area in which the photoelectric conversion element 15 is arranged, and the photoelectric conversion element 15 is set so that its end face is longer than the width of the original D in the main scanning direction, for example, by about 3 mm, so that the image can be read even if the original D transported in the sub-scanning direction is skewed.

[0052] In this embodiment, the image reading area (the width direction length of the image reading surface 201a (see FIG. 3) of the second image reading unit 201) refers to the length X of the photoelectric conversion elements 15 arranged in the main scanning direction, as shown in FIG. 5(b). Here, in the case of a CIS capable of reading an A4-sized document D, for example, if the short side direction is the main scanning direction in which the document D is scanned, then photoelectric conversion elements 15 for approximately 5100 pixels are arranged at a resolution of 600 dpi (dots per inch).

[0053] Returning to FIG. 3, the conductive structure of the first scanning glass 152 and the second scanning glass 202 will be described.

[0054] The surface of the first flow reading glass 152 is subjected to a conductive coating treatment (ITO (Indium Tin Oxide) treatment), and the surface resistivity is set to, for example, 200 to 500 [Ω / cm]. An aluminum sheet 154 made of a conductive member is attached integrally to the upstream edge of the first flow reading glass 152 in the document transport direction (arrow F direction) from the front surface (upper surface) 152a to the back surface (lower surface) 152b of the first flow reading glass 152 with a conductive double-sided tape (not shown).

[0055] The aluminum sheet 154 is electrically connected to a surface 152a of the first moving glass 152. The aluminum sheet 154 is also connected to a conductive housing 155 (see FIGS. 2 and 3) of the image reading device 103, which is made of, for example, sheet metal. The housing 155 is electrically connected to the image forming device main body 101A (see FIG. 1) to ensure electrical continuity throughout the device. In this way, the first moving glass 152 is earthed (frame ground) with the surface 152a thereof being subjected to a conductive coating treatment.

[0056] The second scanning glass 202 has a surface that is electrically conductively coated (ITO treated) and has a surface resistivity of, for example, 200 to 500 [Ω / cm]. Although not shown, an aluminum sheet is attached to the upstream edge of the second scanning glass 202 with an electrically conductive double-sided tape, as with the first scanning glass 152. Also, the second scanning glass 202 is electrically connected to the image forming apparatus main body 101A (see FIG. 1) by a conductive member (not shown) in the same manner as the first scanning glass 152, so that the entire apparatus is electrically connected. In this way, the second scanning glass 202 is earthed (frame ground) with its surface being electrically conductively coated.

[0057] [Regarding existing issues] Recently, it is desired to read an image of a small-sized document D, such as a business card, in a configuration in which a sealed module M having a second image reading unit 201 inside is disposed between the upstream roller 8 and the downstream roller 9 as described above. In order to transport a small-sized document D in the image reading device 103, the distance between the upstream roller 8 and the downstream roller 9 arranged on either side of the second image reading unit 201 in the document transport direction is narrowed. In addition, the upstream guide 410 and the downstream guide 420 are formed small by shortening their transport direction lengths, etc. In this case, as already mentioned, it becomes difficult to reinforce the upstream guide 410 and the downstream guide 420 with the reinforcing ribs, and therefore the rigidity of the upstream guide 410 and the downstream guide 420 decreases. In that case, the upstream guide 410 and the downstream guide 420 are likely to bend when the document D is transported. If bending occurs in the upstream guide 410 and the downstream guide 420 formed on the transport frame 400 (housing), the positions of the upstream roller 8 and the downstream roller 9 will change via the transport frame 400, which could result in a decrease in the accuracy of reading the image of the original D.

[0058] Furthermore, when the sheet conveying speed by the downstream rollers 9 is faster than the sheet conveying speed by the upstream rollers 8, the document D is more likely to be pulled by the downstream rollers 9. When the document D is pulled by the downstream rollers 9, a load is applied to the upstream guide 410 and the downstream guide 420 by the pulled document D, and the upstream guide 410 and the downstream guide 420 are more likely to bend upward. When the upstream guide 410 and the downstream guide 420 bend upward, the document D may move away from the first image reading unit 151 (see FIG. 3).

[0059] At the first image reading position R1, the focal length of the first image reading unit 151 is set to the paper passing surface (surface 152a) of the first flow reading glass 152. At this time, when the document D is transported along the first flow reading glass 152, the distance between the first image reading unit 151 and the document D is the same as the focal length. However, if the upstream guide 410 or the downstream guide 420 is bent upward, the document D may rise upward, so that the document D rises at the first image reading position R1, and the distance between the first image reading unit 151 and the document D changes. At that time, the distance between the first image reading unit 151 and the document D becomes greater than the distance at which the optimal focus for reading the image of the document D is allowed, and it becomes difficult for the first image reading unit 151 to properly read the image. In this embodiment, both the first image reading unit 151 and the second image reading unit 201 are composed of CIS. A typical CIS has a focal length of about 0.3 mm to 0.4 mm. Therefore, if the original D deviates from the focal length at the first image reading position R1 while the original D is being conveyed, the image read by the first image reading unit 151 will be out of focus (out of focus).

[0060] Then, when the rear end of the document D transported in a state where the upstream guide 410 and the downstream guide 420 are bent passes the upstream roller 8, a restoring force acts on the upstream guide 410 and the downstream guide 420, and the bending of the upstream guide 410 and the downstream guide 420 is eliminated. However, this causes the sheet transport speed of the document D to fluctuate during transport, making it particularly difficult for the second image reading unit 201 to properly read the image.

[0061] In view of the above, this embodiment is configured to suppress changes in the positions of the upstream roller 8 and the downstream roller 9 via the transport frame 400 in response to bending of the upstream guide 410 and the downstream guide 420 formed on the transport frame 400 (housing). To achieve this, the upstream guide 410 and the downstream guide 420 are connected by a connecting stay, which will be described later, to suppress bending of the upstream guide 410 and the downstream guide 420. Hereinafter, the connecting stay that connects the upstream guide 410 and the downstream guide 420 will be described using Figures 6 to 10 with reference to Figures 2 and 3.

[0062] As shown in FIG. 6, the image reading device 103 of the present embodiment has a connection stay 600, the above-mentioned sealed module M, and a transport frame unit G in the ADF 1. The connection stay 600, the sealed module M, and the transport frame unit G are combined to form one transport reading unit, and this transport reading unit is disposed in the housing of the ADF 1. In the ADF 1, the transport reading unit is disposed in a space surrounded by a document transport path H that transports the document D from the document feed tray 2 to the document discharge unit 3, as shown in FIG. 2. In detail, the document transport path H has a first discharge path Ha along which the sheets loaded on the document feed tray 2 are transported with their front faces facing up, and a curved connection path Hb that inverts the front and back of the sheets passing through the first discharge path Ha. The document transport path H also has a second discharge path Hc along which the sheets that have been inverted after passing through the connection path Hb are transported with their back faces facing up to the document discharge unit 3. In the space surrounded by the first discharge path Ha, the communication path Hb, and the second discharge path Hc, the second image reading unit 201, the upstream guide 410, the downstream guide 420, and the connection stay 600 are disposed.

[0063] As shown in FIG. 6, the transport frame unit G has a transport frame 400, an upstream roller 8, a downstream roller 9, an upstream guide 410, and a downstream guide 420. In the transport frame unit G, the upstream roller 8 and the downstream roller 9 are rotatably supported by the transport frame 400 as described above. The upstream guide 410 and the downstream guide 420 are supported by the transport frame 400 at both ends in the width direction. In the transport frame unit G, an opening A is formed between the upstream guide 410 and the downstream guide 420. In other words, the upstream guide 410 and the downstream guide 420 are arranged in the transport frame 400 with a gap therebetween that is sufficient to secure the opening A in the document transport direction. In this embodiment, the sealed module M is arranged to be reciprocable so as to be fitted into this opening A.

[0064] Here, in this embodiment, as shown in FIG. 10, the upstream roller 8 is disposed upstream in the transport direction of the second image reading unit 201 so that the upper roller portion 81 of the upstream roller 8 overlaps with a part of the upstream guide 410 when viewed from the width direction of the document D. On the other hand, the downstream roller 9 is disposed downstream in the transport direction of the second image reading unit 201 so that the upper roller portion 91 of the downstream roller 9 overlaps with a part of the downstream guide 420 when viewed from the width direction of the document D. As shown in FIG. 9 and FIG. 10, the roller portion 81 is partially exposed from the transport surface B of the upstream guide 410, and the roller portion 91 is partially exposed from the transport surface BA of the downstream guide 420. In order to achieve this, the upstream guide 410 and the downstream guide 420 are provided with openings for exposing the roller portion 81 and the roller portion 91. Here, an upstream roller 8 having three roller portions 81 arranged at intervals in the width direction and a downstream roller 9 having three roller portions 91 arranged at intervals in the width direction are shown as examples.

[0065] Above the sealed module M, a connecting stay 600 is disposed as a connecting member extending in the document transport direction. When viewed from the width direction of the document D, the connecting stay 600 spans the upstream guide 410 and the downstream guide 420 across the second image reading unit 201 on the opposite side to the document transport path H, connecting the upstream guide 410 and the downstream guide 420. The upstream guide 410 and the downstream guide 420 are fixed to the connecting stay 600, for example, by screws S. As shown in FIG. 10, the connecting stay 600 fixes the upstream guide 410 and the downstream guide 420 on the opposite side to the transport surfaces B and BA facing the document transport path H from the direction intersecting the rotation axis of the upstream roller 8. In this embodiment, the connecting stay 600 fixes the upstream guide 410 and the downstream guide 420 from the direction intersecting the image reading surface 201a (see FIG. 3) of the second image reading unit 201. Here, the connecting stay 600, the upstream guide 410 and the downstream guide 420 are fixed together by screws S that are fastened from above toward below in the direction of gravity.

[0066] 6 to 9, in order to fix the upstream guide 410 and the downstream guide 420 to the connecting stay 600 with screws S, through holes (600a1, 600a2, 600b1, 600b2) through which the screws S pass are formed in the connecting stay 600. Also, corresponding to these through holes, fastening portions (410a, 420a, 410b, 420b) into which the screws S are fastened are formed in the upstream guide 410 and the downstream guide 420, respectively.

[0067] The connecting stay 600 of this embodiment has a first connecting portion 600c extending across the width direction in order to fix the upstream guide 410 at a plurality of points in the width direction. The connecting stay 600 also has second connecting portions 600a, 600b protruding from both ends of the first connecting portion 600c in the width direction toward the downstream side in the document conveying direction in order to fix the downstream guide 420. That is, the through holes 600a1, 600b1 are formed in the first connecting portion 600c in order to fix the upstream guide 410, and the through holes 600a2, 600b2 are formed in the second connecting portions 600a, 600b in order to fix the downstream guide 420. Thus, in the case of this embodiment, as shown in FIG. 7 and FIG. 8, the second connecting portions 600a, 600b of the connecting stay 600 substantially connect the upstream guide 410 and the downstream guide 420 across the second image reading unit 201.

[0068] As described above, in this embodiment, the upstream guide 410 and the downstream guide 420 are connected by the connecting stay 600 arranged so as to straddle the second image reading unit 201 (sealed module M). With this, in a configuration in which the sealed module M having the second image reading unit 201 inside is arranged between the upstream roller 8 and the downstream roller 9, even when an image of a small-sized document D such as a business card is read, the upstream guide 410 and the downstream guide 420 are unlikely to bend. That is, even if the gap between the upstream roller 8 and the downstream roller 9 is narrowed in the image reading device 103 to transport a small-sized document D, the connecting stay 600 ensures the rigidity of the upstream guide 410 and the downstream guide 420. In addition, even if the document D is pulled by the downstream roller 9, since the upstream guide 410 and the downstream guide 420 are unlikely to bend, it is possible to prevent the document D from moving away from a position where the focus at the first image reading position R1 is permitted. In this manner, the accuracy of reading the image of the small-sized original D can be improved with a simple configuration.

[0069] In this embodiment, as shown in FIG. 9, the upstream guide 410 and the downstream guide 420 are fixed by the connecting stay 600 within the range of the length (Q in the figure) of the image reading surface 201a of the second image reading unit 201 in the width direction. In this way, the upstream guide 410 and the downstream guide 420 are less likely to bend due to the pulling of the document D as described above. As a result, even if a force is generated from the document D that tries to press the upstream guide 410 and the downstream guide 420 during reading of the document D, deformation of the downstream end of the upstream guide 410 and the upstream end of the downstream guide 420 can be suppressed, and a good image can be obtained. Furthermore, here, the upstream guide 410 and the downstream guide 420 are fixed by the connecting stay 600 at four points within the image reading range Q, dividing them into four corners. In this way, deformation due to twisting of the conveying surfaces B and BA of the conveying frame 400 can be suppressed.

[0070] In this embodiment, as shown in Fig. 6, in order to bias the sealing module M toward the first running glass 152 by the compression spring 110 (see Fig. 3), mounting parts Ma, Mb are provided on the sealing module M (more specifically, the sealing guide 250). One end of the compression spring 110 is attached to the mounting parts Ma, Mb. On the other hand, the connecting stay 600 is provided with a boss part 600e for attaching the other end of the compression spring 110, as shown in Figs. 6 and 10.

[0071] In this way, the compression spring 110 is disposed between the connecting stay 600 and the sealing module M, and can apply a pressing force to the seat surface of the sealing guide 250. As described above, the connecting stay 600 is disposed across the second image reading unit 201 (sealing module M), so that by attaching the compression spring 110 to the connecting stay 600, the document D can be uniformly abutted against the second running reading glass 202 over the entire width direction. Since the connecting stay 600 receives the reaction force of the compression spring 110 and the pulling force from the document D, the material may be a relatively strong resin such as ABS or PC+ABS, but metal or die-cast is more preferable. In this embodiment, two compression springs 110 are disposed at positions separated in the width direction in order to uniformly abut the document D against the second running reading glass 202 over the entire width direction.

[0072] 10, in this embodiment, the connecting stay 600 fixes the upstream guide 410 at a position overlapping with the roller portion 81 when viewed from the width direction of the document D, and fixes the downstream guide 420 at a position overlapping with the roller portion 91 when viewed from the biasing direction of the compression spring 110. This makes it possible to suppress fluctuations at the downstream tip end side of the upstream guide 410 in the document transport direction, and at the upstream tip end side of the downstream guide 420 in the document transport direction.

[0073] 11, the connecting stay 600 may be formed with a groove 620 in which a bundle K (wiring) of various signal lines including a signal line cable from the second image reading unit 201 can be routed. In this case, it is preferable that the groove 620 is formed with positioning ribs 621 and 622 as positioning parts for positioning the position of the bundle K routed in the groove 620. With this configuration, it is possible to easily route the signal lines of an electric module (not shown) provided in the ADF 1 as the bundle K without adding any additional parts. The positioning ribs 621 and 622 can restrict the movement of the bundle K so that the bundle K does not jump out of the groove 620 when routed.

[0074] In the above-described embodiment, the second image reading unit 201 is housed inside the sealed module M, but it does not have to be housed inside the sealed module M that is sealed.

[0075] In the above-described embodiment, an electrophotographic image forming apparatus 101 has been described. However, instead of this, for example, it is also possible to use an inkjet type image forming apparatus that forms an image on a sheet by ejecting ink liquid from a nozzle. [Explanation of symbols]

[0076] 2...tray (document feed tray), 3...discharge tray (document discharge section), 8...first transport roller (upstream roller), 9...second transport roller (downstream roller), 23...transport means (document feed section), 103...image reading device, 110...urging means (compression spring), 129...image forming means (fixing section), 133...image forming means (image forming section), 201...image reading section (second image reading section), 201a...image reading surface, 400...casing Body (transport frame), 410...first guide portion (upstream guide), 420...second guide portion (downstream guide), 600...connecting member (connecting stay), 600a (600b)...second connecting portion, 600c...first connecting portion, 620...groove portion, 621 (622)...positioning portion (positioning rib), P...sheet, H...sheet transport path (original transport path), Ha...first discharge path, Hb...connecting path, Hc...second discharge path, K...wiring (bundle of wires)

Claims

1. a transparent member that forms a sheet transport path along which a sheet is transported; an opposing member disposed opposite the transparent member and forming the sheet transport path together with the transparent member; an image reading unit that reads an image on a sheet conveyed through the sheet conveying path through the transparent member; a storage member including the transparent member and configured to store the image reading unit; a biasing means for biasing the storage member toward the opposing member; a first guide portion that is disposed adjacent to the storage member on the upstream side of the image reading portion in the sheet conveying direction and that forms the sheet conveying path along which the sheet is conveyed toward the image reading portion; a second guide portion disposed adjacent to the storage member downstream of the image reading portion in the conveying direction and forming the sheet conveying path along which the sheet that has passed through the image reading portion is conveyed; a connecting member that is disposed across the image reading unit and the storage member on the opposite side of the sheet transport path as viewed in a sheet width direction perpendicular to the transport direction, and that connects the first guide unit and the second guide unit, 1. An image reading apparatus comprising:

2. The image reading unit has an image reading surface that reads an image on a sheet being conveyed, the connecting member fixes the first guide portion and the second guide portion to each other at a side opposite to a conveying surface facing the sheet conveying path in a direction intersecting with the image reading surface.

2. The image reading apparatus according to claim 1, wherein the image reading apparatus comprises:

3. The connecting member fixes each of the first guide portion and the second guide portion within the range of the image reading surface in the width direction.

3. The image reading apparatus according to claim 2, wherein the image reading apparatus comprises:

4. A first conveying roller arranged upstream of the image reading unit in the conveying direction so as to overlap a part of the first guide unit when viewed from the width direction; a second conveying roller disposed downstream of the image reading unit in the conveying direction so as to overlap a part of the second guide portion when viewed from the width direction; a housing that rotatably supports the first conveying roller and the second conveying roller, The first guide portion and the second guide portion are formed on the housing so that both ends in the width direction of each of the first guide portion and the second guide portion are supported.

4. The image reading apparatus according to claim 1, wherein the image reading apparatus is a scanning apparatus.

5. a second image reading unit that is provided on the opposite side of the sheet transport path from the image reading unit and that reads an image on a second side of the sheet transported on the sheet transport path, the second side being opposite to the first side read by the image reading unit; the other image reading unit is disposed upstream of the image reading unit in the transport direction.

5. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

6. The connecting member has a first connecting portion extending in the width direction and fixing the first guide portion at a plurality of points in the width direction, and a second connecting portion protruding from the first connecting portion toward a downstream side in the conveying direction and fixing the second guide portion.

6. The image reading apparatus according to claim 5,

7. The connecting member supports one end of the biasing means.

7. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

8. The connecting member has a groove portion for routing a wiring, and a positioning portion for positioning the wiring routed in the groove portion.

8. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

9. A tray for loading sheets; a conveying means for conveying the sheets stacked on the tray to the sheet conveying path; a discharge tray for stacking the sheets conveyed and discharged by the conveying means, The tray and the discharge tray are disposed one above the other, the sheet transport path includes a first discharge path along which the sheets stacked on the tray are transported with their front sides facing up, a curved connection path along which the sheets that have passed through the first discharge path are transported with their front sides turned up, and a second discharge path along which the inverted sheets are transported with their back sides facing up to the discharge tray, the image reading unit, the first guide unit, the second guide unit, and the connecting member are disposed in a space surrounded by the first discharge path, the communication path, and the second discharge path; 9. The image reading apparatus according to claim 1, wherein the image reading apparatus is a digital camera.

10. An image reading device according to any one of claims 1 to 9, and an image forming means for forming an image on another sheet based on information of the image read from the sheet by the image reading device.

1. An image forming apparatus comprising:

Images