Image reading device and image forming device

Abstract

To suppress generation of paper dust or the like due to the tip of a guide member rubbing against a sheet.SOLUTION: An image reading device has a transparent member, conveyance means for conveying a sheet, reading means for reading image information through the transparent member from the sheet conveyed by the conveyance means, and a guide member arranged upstream of a reading position where the reading means reads image information from the sheet in a sheet conveyance direction and guides the sheet. The guide member is formed of an elastic sheet material, and a tip of the guide member is a folded part where the sheet material is folded back.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image reading device that reads image information from a sheet, and an image forming device that forms an image on a sheet. [Background technology]

[0002] Conventionally, known image reading devices include devices that read image information from an original document and devices that read image information on a recording material on which an image has been formed by an image forming apparatus and feed the information back to the image forming apparatus. Image reading devices acquire image information by optically scanning a sheet conveyed along the surface of a transparent member such as a reading glass using a reading means such as a contact image sensor (CIS). Patent Document 1 describes a method in which a sheet-like guide member arranged to protrude upstream from the contact glass in the document conveyance direction guides the leading edge of the original document conveyed from upstream to the surface of the contact glass. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-69043 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the tip of the guide member that guides the sheet toward the transparent member has a sharp edge, pressure is concentrated at the contact point between the sheet and the tip of the guide member. As a result, foreign matter such as paper dust and toner may be generated at the tip of the guide member and adhere to the surface of the transparent member. The adhesion of such foreign matter can cause streaky noise in the image data read by the reading means.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an image reading device that can suppress the generation of paper dust and the like, and an image forming apparatus that includes the same. [Means for solving the problem]

[0006] One aspect of the present invention is an image reading device comprising a transparent member, a conveying means for conveying a sheet, a reading means for reading image information from the sheet conveyed by the conveying means through the transparent member, and a guide member for guiding the sheet, the guide member being arranged upstream in the sheet conveying direction from a reading position where the reading means reads image information from the sheet, wherein the guide member is formed from an elastic sheet material and the tip of the guide member is a folded portion where the sheet material is folded back. [Effects of the Invention]

[0007] According to the present invention, the generation of paper dust and the like can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to a first embodiment. [Figure 2] FIG. 2 is a schematic view showing the inside of the inspection device according to the first embodiment. [Figure 3] FIG. 2 is a diagram showing a first reading unit of the inspection device according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing a first reading unit of the inspection device according to the first embodiment. [Figure 5] FIG. 2 is a diagram showing a second reading unit of the inspection device according to the first embodiment. [Figure 6] FIG. 2 is a diagram showing a second reading unit of the inspection device according to the first embodiment. [Figure 7] FIG. 10 is a perspective view of a document reading device according to a second embodiment. [Figure 8] FIG. 10 is a schematic diagram of a document reading device according to a second embodiment. [Figure 9] FIG. 10 is a diagram showing a first reading unit and a second reading unit of a document reading device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] First Embodiment 1 is a schematic diagram showing an image forming system 100 as an image forming apparatus according to a first embodiment. The image forming system 100 has a configuration in which an inspection device 102 and a sorting device 103 are connected downstream of a printer 101 as an image forming apparatus main body equipped with an image forming function.

[0011] The printer 101 is a full-color printer equipped with an image forming mechanism 10 that forms an image on a recording material P by an electrophotographic process using four color toners. The printer 101 forms an image on the recording material P based on image information input to the control unit from an external device (not shown) such as an information terminal such as a personal computer or an image reader. The recording material P can be a variety of sheets of different sizes and materials, including paper such as plain paper and cardboard, surface-treated sheet materials such as plastic film, cloth, and coated paper, and sheet materials with special shapes such as envelopes and index paper.

[0012] The printer 101 also includes a feeding / conveying section 13, a branching / discharging section 25, an inverting section 26, and a re-feeding section 27 as mechanisms for conveying the recording material P. The printer 101 also includes an operation section 21 that is a user interface for the image forming system 100. A user can input setting information and give instructions to the image forming system 100 to form an image by operating a touch panel or the like of the operation section 21 or an external device connected to the image forming system 100.

[0013] The image forming mechanism 10 has four image forming units (process units, image forming stations) PY, PM, PC, and PK that create toner images of yellow, magenta, cyan, and black, respectively. Each of the image forming units PY to PK includes a photosensitive drum 1 as an image carrier (electrophotographic photosensitive member), a charger 2, a laser scanner 3, a developing unit 4, a primary transfer roller 6, and a drum cleaner 7.

[0014] The four imaging units PY to PK are arranged along an intermediate transfer belt 50 serving as an intermediate transfer body. The intermediate transfer belt 50 is stretched around a drive roller 51, a tension roller 52, and a secondary transfer inner roller 53, and is driven to be transported in the direction of arrow R in the figure. A secondary transfer roller 14 serving as a transfer member is arranged at a position facing the secondary transfer inner roller 53 across the intermediate transfer belt 50. A secondary transfer unit 15, which is a transfer unit in this embodiment where an image (toner image) is transferred to the recording material P, is a nip between the secondary transfer roller 14 and the intermediate transfer belt 50. A belt cleaner 19 is also arranged at a position facing the intermediate transfer belt 50.

[0015] When the printer 101 receives an instruction to start an image forming operation, it starts driving the photosensitive drums 1 of each of the imaging units PY to PK and the intermediate transfer belt 50. The charger 2 uniformly charges the surface of the photosensitive drum 1. The laser scanner 3 irradiates the surface of the photosensitive drum 1 with laser light modulated based on an image signal (video signal) generated from image information, and writes an electrostatic latent image on the surface of the photosensitive drum 1. The developer 4 develops the electrostatic latent image using yellow, magenta, cyan, or black toner. As a result, a monochromatic toner image is formed on the surface of each photosensitive drum 1.

[0016] The single-color toner images carried on the four photosensitive drums 1 are primarily transferred onto the intermediate transfer belt 50 by the primary transfer rollers 6. At this time, the toner images of each color are transferred in multiple layers so that they overlap each other, forming a full-color image on the surface of the intermediate transfer belt 50. This full-color image is transported toward the secondary transfer unit 15 while still being carried on the intermediate transfer belt 50. Note that any deposits such as residual toner that remain on the surfaces of the photosensitive drums 1 without being transferred to the intermediate transfer belt 50 are removed by a drum cleaner 7.

[0017] In parallel with the above-described toner image creation process in the image forming mechanism 10, the feeding / conveying section 13 supplies the recording materials P one by one from the cassette 24 to the secondary transfer section 15. The cassette 24 is a storage container that stores a large number of recording materials P. The feeding / conveying section 13 includes a feeding unit that separates and feeds the recording materials P stored in the cassette 24 one by one, and a plurality of transport units arranged along the recording material transport path from the cassette 24 to the secondary transfer section 15. The plurality of transport units includes a registration roller pair that corrects skew of the recording material P and controls the transport timing of the recording material P to synchronize with the toner image creation process by the image forming mechanism 10.

[0018] When the recording material P reaches the secondary transfer portion 15, a predetermined voltage is applied to the secondary transfer roller 14, and the full-color image on the intermediate transfer belt 50 is transferred (secondary transfer) onto the recording material P. Note that any deposits such as residual toner that are not transferred to the recording material P and remain on the surface of the intermediate transfer belt 50 are removed by a belt cleaner 19.

[0019] The recording material P that has passed through the secondary transfer unit 15 is introduced into a thermal fixing device 16. The fixing device 16 has a pair of rotating bodies such as a pair of rollers that sandwich and transport the recording material P, and a heating means such as a halogen lamp for heating the image on the recording material P that passes through a nip portion (fixing nip) of the pair of rotating bodies. The toner is heated and pressurized as it passes through the fixing nip, and then becomes fixed on the recording material P, resulting in a fixed image.

[0020] In the case of single-sided printing, the recording material P that has passed through the fixing device 16 is discharged from the printer 101 by a pair of discharge rollers 17 of the branching and discharging section 25 and delivered to an inspection device 102. In the case of double-sided printing, the recording material P that has passed through the fixing device 16 with an image formed on its front side is conveyed to an inverting section 26 via a conveying path branched by the branching and discharging section 25. The recording material P is then inverted and conveyed (switched back) in the inverting section 26 and fed again to the image forming mechanism 10 via a re-feeding section 27 and the feeding and conveying section 13. Then, the recording material P, on which an image has been formed on its back side while passing through the secondary transfer section 15 and the fixing device 16, is discharged from the printer 101 by a pair of discharge rollers 17 and delivered to an inspection device 102.

[0021] The inspection device 102 is disposed between the printer 101, which is an upstream device, and the sorting device 103, which is a downstream device. When the image forming system 100 is viewed from the front (viewpoint in FIG. 1), the inspection device 102 is disposed between the printer 101 and the sorting device 103 in the horizontal direction.

[0022] The inspection device 102 has reading units 202 and 204 that read image information from a recording material (sheet) and is a device that detects whether or not there is an abnormality in the image on the recording material P received from the printer 101 based on the read image information. For example, a recording material P on which a reference image is recorded is first passed through the inspection device 102, and the image information read by the reading units 202 and 204 is registered as a reference image in a computer connected to the image forming system 100. Thereafter, the image information of the recording material P (the recording material P to be inspected) conveyed from the printer 101 is read by the reading units 202 and 204 and transmitted to the computer. The computer compares the read image information with the registered reference image. If a difference exceeding an allowable range (for example, a density difference or misalignment of feature points) is detected, the computer determines that there is an abnormality in the image on that recording material P.

[0023] The recording material P discharged from the inspection device 102 is received by the sorting device 103. The sorting device 103 switches the discharge destination of the recording material P depending on the result of the determination made by the inspection device 102 as to whether or not there is an abnormality in the image. Specifically, the discharge path of the recording material P is switched by the switching guide 131 so that the recording material P determined to be normal is discharged to the lower discharge tray 132, and the recording material P determined to be abnormal is discharged to the upper discharge tray 133. This completes a series of image forming operations in the image forming system 100.

[0024] In this embodiment, the image forming mechanism 10 is an intermediate transfer type, but a direct transfer type image forming mechanism that transfers a toner image directly from an image carrier to a recording material without using an intermediate transfer body may be used. Also, a mechanism other than an electrophotographic type, such as an inkjet type image forming unit or an offset printing mechanism, may be used as the image forming mechanism.

[0025] 1 is an example, and for example, a sheet processing device (finisher) that performs processing such as bookbinding and punching on the recording material P may be arranged in place of the sorting device 103. Also, a discharge tray may be provided in the inspection device 102, and the inspection device 102 may discharge the recording material P as a product.

[0026] (Inspection equipment) Next, the internal configuration of the inspection device 102 as an image reading device according to this embodiment will be described.

[0027] As described above, the inspection device 102 is disposed between the printer 101 and the sorting device 103 in the horizontal direction (FIG. 1), and conveys the recording material received from the printer 101 toward the sorting device 103. Therefore, the recording material conveying path of the inspection device 102 extends from an entrance Pi that opens on one side (the right side in the drawing) of the inspection device 102 in the horizontal direction to an exit Po that opens on the other side (the left side in the drawing). In particular, this embodiment employs a configuration in which the recording material conveying path inside the inspection device 102 extends linearly in a substantially horizontal direction when viewed from the front side.

[0028] 2, the inspection device 102 has a conveying roller pair 210 (entrance roller pair), a reading unit 202 (first reading unit), a reading glass 302 (first reading glass), and a pressure roller (platen roller) 203. The inspection device 102 also has a reading unit 204 (second reading unit), a reading glass 308 (second reading unit), a pressure roller (platen roller) 205, and a conveying roller pair 220 (exit roller pair). The inspection device 102 also has a plurality of conveying guides (221, 222, 224, 225) that form a recording material conveying path, and an entrance sensor 223 and an exit sensor 226 as detection means for detecting the recording material conveyed on the recording material conveying path.

[0029] The reading unit 202, the reading glass 302, and the pressure roller 203 constitute a first reading section R1 that reads image information from the first side of the recording material. The reading unit 204, the reading glass 308, and the pressure roller 205 constitute a second reading section R2 that reads image information from the second side of the recording material.

[0030] In the following description, the recording material conveying direction D1 refers to the direction in which the recording material moves at the reading position P1 of the reading unit 202. The vertical direction D2 refers to a direction perpendicular to the paper passing surface 302a of the reading glass 302 (the height direction relative to the reading glass 302). In other words, the vertical direction D2 is a direction perpendicular to both the recording material conveying direction D1 and the sheet width direction at the reading position P1 of the reading unit 202. The vertical direction D2 is also the depth of field direction of the reading unit 202. The sheet width direction is a direction perpendicular to the recording material conveying direction D1. The sheet width direction is also the rotation axis direction of the conveying roller pairs 210, 220 and the main scanning direction of the reading units 202, 204.

[0031] In this embodiment, the recording material conveyance direction D1', which is the direction of movement of the recording material at the reading position P2 of the other reading unit 204, is substantially the same as the above-mentioned recording material conveyance direction D1. Furthermore, the vertical direction D2', which is perpendicular to the paper passing surface 308a of the reading glass 308, is substantially the same as the above-mentioned vertical direction D2. For simplicity, the configuration around the reading unit 204 will also be described below using the recording material conveyance direction D1 and the vertical direction D2. However, in cases such as when the recording material conveyance path is bent between the reading positions P1 and P2 of the two reading units 202 and 204, the recording material conveyance direction D1' and the vertical direction D2' at the reading position P2 may not coincide with the above-mentioned recording material conveyance direction D1 and the vertical direction D2. In such cases, the configuration of the second reading unit R2 is based on the recording material conveyance direction D1' and the vertical direction D2' instead of the recording material conveyance direction D1 and the vertical direction D2.

[0032] The reading unit 202 is a reading means (first reading means) that reads image information from a first surface (the lower surface in the drawing) of the recording material conveyed on the recording material conveyance path through a reading glass 302 as a transparent member (first transparent member). The reading unit 204 is a reading means (second reading means) that reads image information from a second surface (the upper surface in the drawing) opposite to the first surface of the recording material conveyed on the recording material conveyance path through a reading glass 308 as a transparent member (second transparent member).

[0033] The reading units 202 and 204 are contact image sensors (CIS). Specifically, the reading units 202 and 204 each include a light source that irradiates light onto the recording material passing through the reading positions P1 and P2, a sensor board on which image sensors (light-receiving elements) are arranged in the sheet width direction, and a lens that focuses the light reflected from the recording material onto the light-receiving surface of the image sensor. The light source may be, for example, an LED on the sensor board and a light guide that irradiates the recording material with the LED light while diffusing it uniformly in the sheet width direction. The sensor board of the reading unit 202 faces the rear surface of the reading glass 302 in the vertical direction D2 at the reading position P1, and the sensor board of the reading unit 204 faces the rear surface of the reading glass 308 in the vertical direction D2 at the reading position P2. The reading units 202 and 204 optically scan the surface of the recording material at the reading positions P1 and P2, and obtain image information from the recording material by photoelectrically converting the optical image incident through the reading glasses 302 and 302 using the image pickup elements.

[0034] It should be noted that the reading units 202 and 204 may be configured as a CCD type, which uses a charge-coupled device as an image sensor and forms an image of the light reflected from the recording material using a reduction optical system with multiple mirrors. If the reading units 202 and 204 are of the CIS type, this is advantageous in terms of cost and size compared to the CCD type, but because the depth of field is shallow, the positional accuracy of the recording material in the vertical direction D2 is important to ensure reading accuracy.

[0035] The reading glass 302 is disposed at the reading position P1 and faces the pressure roller 203, which is an opposing member, in the vertical direction D2, across a space (gap) through which the recording material passes. The reading glass 302 has a paper passing surface 302a that extends in the recording material conveyance direction D1 and the sheet width direction on the surface facing the pressure roller 203 in the vertical direction D2 (the side of the space through which the recording material passes). The position of the paper passing surface 302a of the reading glass 302 in the vertical direction D2 is set to match the focal position of the reading unit 202.

[0036] The reading glass 308 is disposed at the reading position P2 and faces the pressure roller 205, which is an opposing member, in the vertical direction D2, across a space (gap) through which the recording material passes. The reading glass 308 has a paper passing surface 308a that extends in the recording material conveyance direction D1 and the sheet width direction on the surface facing the pressure roller 205 in the vertical direction D2 (the side of the space through which the recording material passes). The position of the paper passing surface 308a of the reading glass 308 in the vertical direction D2 is set to match the focal position of the reading unit 204.

[0037] The upstream conveying roller pair 210 is arranged upstream of the reading position P1 of the reading unit 202 in the recording material conveying direction D1, and conveys the recording material that has been conveyed to the recording material conveying path through the entrance Pi toward the reading position P1. The downstream conveying roller pair 220 is arranged downstream of the reading position P2 of the reading unit 204 in the recording material conveying direction D1, and conveys the recording material that has passed the reading position P2 toward the exit Po of the recording material conveying path.

[0038] The conveying roller pair 210 and 220 are an example of a conveying unit that conveys a sheet to be read through the reading position P1 of the reading unit 202. The conveying roller pair 210 is an example of a first roller pair arranged upstream of the reading position P1 in the sheet conveying direction, and the conveying roller pair 220 is an example of a second roller pair arranged downstream of the reading position P1 in the sheet conveying direction. In this embodiment, the two reading units 202 and 204 are adjacent to each other, but another conveying roller pair (hereinafter referred to as an intermediate roller pair) may be arranged between the reading units 202 and 204 in the recording material conveying direction D1. In a configuration with an intermediate roller pair, the nip line for the first reading unit R1 is a straight line passing through the nip portions of the conveying roller pair 210 and the intermediate roller pair, and the nip line for the second reading unit R2 is a straight line passing through the nip portions of the intermediate roller pair and the conveying roller pair 220.

[0039] The upstream conveying roller pair 210 is composed of a drive roller 211 and a roller 212, which is a driven roller that rotates following the drive roller 211. The drive roller 211 has a steel shaft 211a extending in the sheet width direction, and two outer circumferential portions (recording material contact portions, roller bodies) 211b made of silicone rubber and having an outer diameter of 20 mm attached to the shaft 211a. The rollers 212 are provided at positions corresponding to the outer circumferential portions 211b of the drive roller 211 in the sheet width direction and are made of POM (polyacetal resin). The shaft portion of the roller 212 is rotatably supported by the frame of the inspection device 102, and is pressed against the drive roller 211 with a total biasing force of 10 N by a spring member (not shown). When the drive roller 211 is driven to rotate by the power of a motor (not shown), the conveying roller pair 210 conveys the recording material by nipping it in a nip portion N1 between the drive roller 211 and the roller 212.

[0040] The downstream conveying roller pair 220 has substantially the same configuration as the upstream conveying roller pair 210. That is, the conveying roller pair 220 has a drive roller and a roller which is a driven roller that rotates following the drive roller, and conveys the recording material by sandwiching it in a nip portion N2 between the drive roller and the roller.

[0041] Hereinafter, when viewed in the sheet width direction, a nip line Ln is defined as an imaginary line passing through the nip portions N1 and N2 of the upstream and downstream conveying roller pairs 210 and 220. In this embodiment, the direction of the nip line Ln is substantially parallel to the recording material conveying direction D1.

[0042] Of the multiple conveyance guides provided in the inspection device 102, the lower entrance guide 221 and the upper entrance guide 222 extend from the downstream side of the nip portion N1 of the conveyance roller pair 210 to the upstream side of the nip portion N1 in relation to the recording material conveyance direction D1, and form the entrance Pi of the recording material conveyance path. On the upstream side of the nip portion N1, the lower entrance guide 221 and the upper entrance guide 222 are inclined with respect to the recording material conveyance direction D1 so as to move away from each other in the vertical direction D2 toward the upstream side in the recording material conveyance direction D1 (that is, so that the opening width of the entrance Pi increases).

[0043] Of the multiple conveyance guides provided in the inspection device 102, the lower exit guide 224 and the upper exit guide 225 extend from the upstream side of the nip portion N2 of the conveyance roller pair 220 to the downstream side of the nip portion N2 in relation to the recording material conveyance direction D1, and form the exit Po of the recording material conveyance path. On the upstream side of the nip portion N2, the lower exit guide 224 and the upper exit guide 225 are inclined with respect to the recording material conveyance direction D1 so as to move away from each other in the vertical direction D2 toward the upstream side of the recording material conveyance direction D1.

[0044] A recording material conveying path is formed as a space through which the recording material passes in the vertical direction D2 between the entrance guide lower portion 221 and the entrance guide upper portion 222, and between the exit guide lower portion 224 and the exit guide upper portion 225. In addition, a recording material conveying path is also formed in the vertical direction D2 between the reading glass 302 and the pressure roller 203, and between the reading glass 308 and the pressure roller 205.

[0045] SUS420CP (martensitic stainless steel) can be used as the material for the lower inlet guide 221, upper inlet guide 222, lower outlet guide 224, and upper outlet guide 225. It is also preferable to polish the surfaces that come into contact with the recording material to increase the smoothness of the surfaces and prevent scratches on the recording material.

[0046] In this embodiment, the recording material conveyance path from the conveyance roller pair 210 upstream of the reading positions P1 and P2 to the conveyance roller pair 220 downstream of the reading positions P1 and P2 is a straight path that extends linearly when viewed in the sheet width direction. In other words, the conveyance guides (221, 222, 224, 225), the reading glasses 302 and 308, the pressure rollers 203 and 205, and other components that form the recording material conveyance path are arranged along the nip line Ln without essentially intersecting with (intersecting with) the nip line Ln. This allows the recording material passing through the reading positions P1 and P2 to be conveyed while maintaining a posture that extends linearly (flat) along the nip line Ln when viewed in the sheet width direction.

[0047] Note that any of the conveyance guide, reading glasses 302, 308, or pressure rollers 203, 205 may be arranged to slightly intrude into the nip line Ln. In this case, it is preferable that the intrusion amount be sufficiently small (for example, 5 mm or less, preferably 1 mm or less in the vertical direction D2) so that the recording material is in a state close to a linear (flat) state. Also, in this embodiment, the paper passing surfaces 302a, 308a of the reading glasses 302, 308 extend substantially parallel to the nip line Ln, but the paper passing surfaces 302a, 308a may be slightly inclined in the downstream direction of the recording material conveyance direction D1 so as to approach the nip line Ln.

[0048] The entrance sensor 223 is disposed upstream of the pair of conveying rollers 210 in the recording material conveying direction D1. The exit sensor 226 is disposed downstream of the pair of conveying rollers 220 in the recording material conveying direction D1. Known sensor configurations capable of detecting sheet-shaped recording materials can be used for the entrance sensor 223 and the exit sensor 226. For example, a photoelectric sensor (photoreflector) that irradiates light toward the recording material conveying path and detects light reflected from the recording material can be used. Alternatively, a photoelectric sensor (photointerrupter) that is shielded from light by the flag member protruding into the recording material conveying path may be used to detect when a flag member is pressed against the recording material and swings.

[0049] (Operation of inspection device) The following describes a series of operations in which the inspection device 102 reads image information while conveying a recording material. The recording material P enters the recording material conveyance path through the entrance Pi, and is guided to the nip N1 of the conveyance roller pair 210 while being prevented from flapping (positional deviation) in the vertical direction D2 by the tapered lower entrance guide 221 and upper entrance guide 222. During this process, the leading edge of the recording material is detected by the entrance sensor 223, and the control unit of the inspection device 102 recognizes that the recording material has been conveyed from the printer 101.

[0050] The control unit of the inspection device 102 determines the timing to start reading image information by the reading units 202 and 204 based on the detection timing of the inlet sensor 223. In addition, if the inlet sensor 223 does not detect the recording material until a predetermined time based on the recording material conveyance information notified from the printer 101 has elapsed, the control unit detects a recording material conveyance abnormality (jam) based on the detection result of the inlet sensor 223.

[0051] The recording material that has reached the conveying roller pair 210 is conveyed along the paper passing surfaces 302a, 308a of the reading glasses 302, 308. During this time, the image information on the first side of the recording material is read by the reading unit 202 as it passes through reading position P1, and the image information on the second side of the recording material is read by the reading unit 204 as it passes through reading position P2. In other words, the inspection device 102 can read image information from both sides of the recording material while the recording material passes through the recording material conveyance path only once, without having to reverse or convey the recording material. Here, the conveyance speed of the recording material P discharged from the printer 101 and the conveyance speed of the recording material P in the inspection device 102 are substantially the same.

[0052] The recording material that has passed the reading position P2 of the downstream reading unit 204 is guided to the nip portion N2 of the conveying roller pair 220 by the lower exit guide 224 and the upper exit guide 225. The conveying roller pair 220 then ejects the recording material through the exit Po to the outside of the inspection device 102 and passes it to the sorting device 103. During this process, the exit sensor 226 detects the trailing edge of the recording material, and the control unit of the inspection device 102 recognizes that the ejection of the recording material has been completed. The control unit of the inspection device 102 also detects abnormalities in the conveyance of the recording material (jams) based on the detection results of the exit sensor 226.

[0053] The inspection device 102 is a device that reads image information from various recording materials of different materials, including thin paper with low stiffness and thick paper with high stiffness. In this embodiment, image information is read while the recording material is transported along a straight path that extends linearly from the transport roller pair 210 on the upstream side of the reading positions P1 and P2 to the transport roller pair 220 on the downstream side. This makes it possible to prevent unnecessary external forces from acting on the recording material while it is transported past the reading positions P1 and P2, causing the position of the recording material to deviate from the ideal (flutter) in the recording material transport direction D1 or the perpendicular direction D2.

[0054] If the conveyance speed of the recording material fluctuates, this will lead to changes in the magnification and geometric variation of the read image, and if the position of the recording material in the vertical direction D2 shifts, the accuracy of the read image will decrease (the image will become blurred). In response to this, this embodiment employs a straight path configuration, and the reading glasses 302 and 308 are positioned within the straight path to match the focal positions of the reading units 202 and 204. This prevents the position of the recording material from shifting from the ideal (fluttering) in the recording material conveyance direction D1 or the vertical direction D2, making it possible to accurately read correct image information for recording materials of different materials.

[0055] In this embodiment, to further improve reading accuracy, the paper passing surfaces 302a, 308a of the reading glasses 302, 308 are positioned so that they substantially coincide with the nip line Ln. As a specific example, it is preferable that the paper passing surfaces 302a, 308a at the reading positions P1, P2 are positioned within 3 mm, more preferably within 1 mm, of the nip line Ln in the vertical direction D2, and they may be set directly above the nip line Ln. By positioning the reading glasses 302, 308 in this manner, the recording material P passing through the reading positions P1, P2 is stretched more straight, making it less likely that the recording material P will bend, which could lead to a decrease in reading accuracy.

[0056] It is preferable that the lower entrance guide 221 and the upper entrance guide 222 extend substantially parallel to each other in the recording material conveyance direction D1 around and downstream of the nip portion N1 of the conveying roller pair 210. At the reading positions P1 and P2, it is preferable that the paper passing surfaces 302a and 308a of the reading glasses 302 and 308 extend substantially parallel to the nip line Ln in the recording material conveyance direction D1. It is preferable that the lower exit guide 224 and the upper exit guide 225 extend substantially parallel to each other in the recording material conveyance direction D1 around and downstream of the nip portion N2 of the conveying roller pair 220.

[0057] (Details of the first reading unit) Next, the first reading unit R1 and the guide member 305 provided in the first reading unit R1 will be described in detail with reference to Figures 3 and 4. Figure 3 is a diagram of the first reading unit R1 as viewed in the sheet width direction, and Figure 4 is a diagram showing how the recording material P passes through the first reading unit R1.

[0058] 3, the first reading unit R1 is provided with a guide member 305 made of an elastic sheet material 305a (sheet material, film material, first sheet material). The guide member 305 has a double-sided tape 304 attached to one surface of the elastic sheet material 305a, and is bonded via the double-sided tape 304 to a metal plate 306 serving as a support member.

[0059] Here, the tip 303 of the guide member 305 is a folded portion formed by folding back a portion of the elastic sheet material 305a (a3) ​​so that it overlaps with another portion of the elastic sheet material 305a (a2). Specifically, the elastic sheet material 305a includes a first region a1 serving as a supported portion (base) supported (fixed) by the metal plate 306, a second region a2 extending downstream in the recording material conveyance direction D1 from the first region a1, and a third region a3 folded back relative to the second region a2. The third region a3 extends from the downstream end of the second region a2 in the recording material conveyance direction D1 to the upstream side in the recording material conveyance direction D1 and overlaps with the second region a2. Therefore, the tip 303 of the guide member 305 of this embodiment is a folded portion formed by folding back the third region a3 of the elastic sheet material 305a so that it overlaps with the second region a2.

[0060] The third region a3 of the elastic sheet material 305a is adhered to the second region a2 by the double-sided tape 304. This allows the guide member 305 to maintain the shape of the folded elastic sheet material 305a. In other words, the end surface a4 of the elastic sheet material 305a is not exposed at the tip portion 303 of the guide member 305. This helps prevent the generation of paper dust, as described below. In addition, the double-sided tape 304 serves to adhere the guide member 305 to the metal plate 306 and to bond the second region a2 and the third region a3 of the guide member 305 together, thereby reducing costs. The end surface a4 is, for example, the cut surface when the elastic sheet material 311a is cut from the original sheet.

[0061] The elastic sheet material 305a is folded back so that the area including the end surface a4 (third area a3) is located behind the area not including the end surface a4 (second area a2) when viewed from the side of the space through which the recording material passes (the upper side in the figure) in the vertical direction D2. In other words, the end surface a4 of the elastic sheet material 305a is located on the opposite side of the second area a2 of the elastic sheet material 305a from the space through which the recording material passes. This prevents the recording material being transported through the space from getting caught on the end surface a4 of the elastic sheet material 305a.

[0062] The elastic sheet material 305a is made of a material having enough elasticity to bend when pressed against a general recording material. Therefore, the rigidity of the elastic sheet material 305a is lower than that of the above-mentioned conveying guides (221, 222, 224, 225) and the below-mentioned opposing guide 307, which have rigidity that allows negligible bending even when pressed against a recording material. As an example, the elastic sheet material 305a is made of an ultra-high molecular weight polyethylene film.

[0063] The elastic sheet material 305a preferably has a Young's modulus of 0.8 GPa to 1.2 GPa. If the Young's modulus is too low, the guide member 305 may deform even with a very weak force, resulting in insufficient guiding performance. If the Young's modulus is too high, the contact pressure between the tip 303 of the guide member 305 and the recording material increases, making paper dust and other particles more likely to be generated. Furthermore, the elastic sheet material 305a preferably has a volume resistivity of 10^3 Ω·cm to 10^5 Ω·cm. By setting the volume resistivity within this range, the conductive double-sided tape 304 provided on the inside of the folded elastic sheet material 305a, as described below, can more easily adsorb paper dust and other particles to the surface of the guide member 305. In the example using the ultra-high molecular weight polyethylene film described above, the film thickness was 0.1 mm, the Young's modulus was 1.0 GPa, and the volume resistivity was 10^4 Ω·cm.

[0064] The double-sided tape 304 is preferably made of a conductive material, such as aluminum foil tape. Its thickness is, for example, 0.1 mm. The double-sided tape 304 is an example of an adhesive layer provided on the inner surface of the folded portion of the elastic sheet material 305a; for example, an adhesive may be applied to one side of the elastic sheet material 305a. Furthermore, for example, the overlapping portions of the folded elastic sheet material 305a may be adhered (fixed) by methods such as heat welding, single-sided tape, or staples.

[0065] The guide member 305 is disposed upstream of the reading position P1 in the recording material conveyance direction D1, and is disposed on the same side as the reading glass 302 with respect to the space through which the recording material passes in the vertical direction D2. The guide member 305 extends from a first region a1 supported by a metal plate 306 downstream in the recording material conveyance direction D1 and toward the side of the space through which the recording material passes in the vertical direction D2 (upper side in the drawing).

[0066] The length of the guide member 305 in the sheet width direction is set to be equal to or greater than the width in the sheet width direction of the paper passing surface 302a of the reading glass 302. When the recording material is not being conveyed, the guide member 305 is arranged without contact with the reading glass 302, with a predetermined gap (for example, about 1 mm) between them. When viewed from the upstream side to the downstream side in the recording material conveyance direction D1, the guide member 305 covers at least a part (preferably the entirety) of the paper passing surface 302a of the reading glass 302.

[0067] A tip 303 of the guide member 305 protrudes in the vertical direction D2 toward the space through which the recording material passes (upper side in the drawing) beyond a paper passing surface 302a of the reading glass 302. In particular, the tip 303 of the guide member 305 protrudes in the vertical direction D2 toward the space through which the recording material passes, relative to an upstream end 302e of the paper passing surface 302a extending at least in the recording material conveyance direction D1. In the illustrated configuration example, the paper passing surface 302a is tapered, and the upstream end 302e of the paper passing surface 302a is located downstream of a side surface 302b of the reading glass 302 that is upstream in the recording material conveyance direction D1.

[0068] Furthermore, the tip of the guide member 305 is intruding into the nip line Ln in the vertical direction D2, that is, the guide member 305 intersects with the nip line Ln.

[0069] An opposing guide 307 is disposed at a position facing at least a portion of the guide member 305 in the vertical direction D2. The opposing guide 307 faces the surface of the recording material opposite the surface that contacts the guide member 305, and is a conveyance guide that guides the recording material into the gap between the reading glass 302 and the pressure roller 203. The opposing guide 307 extends downstream in the recording material conveyance direction D1 and toward the nip line Ln in the vertical direction D2. A tip 307a of the opposing guide 307 faces a paper passing surface 302a of the reading glass 302 in the vertical direction D2, upstream of the reading position P1 in the recording material conveyance direction D1. Unlike the guide member 305, the opposing guide 307 has rigidity such that deflection is negligible even when pressed by the recording material, and the tip 307a of the opposing guide 307 is positioned so that it does not enter the nip line Ln. The opposing guide 307 is made of, for example, the same stainless steel as the above-mentioned conveying guides (221, 222, 224, 225).

[0070] 4, when recording material P is conveyed to first reading unit R1, the recording material P is conveyed while contacting guide member 305. Here, when recording material P is not being conveyed, tip end 303 of guide member 305 protrudes in vertical direction D2 beyond paper passing surface 302a of reading glass 302. Therefore, recording material P is smoothly conveyed without getting caught on the edge portion of upstream end 302e of paper passing surface 302a of reading glass 302 or on upstream side surface 302b of reading glass 302.

[0071] Furthermore, because the guide member 305 is made of an elastic sheet material 305a, when pressed against the recording material P, the guide member 305 bends and the leading end 303 retreats to the position of the nip line Ln. This prevents the surface of the recording material P from rubbing strongly against the leading end 303 of the guide member 305.

[0072] Furthermore, in this embodiment, the tip 303 of the guide member 305 is formed by a folded portion of the elastic sheet material 305a. Therefore, the tip 303 has a curved surface that is more smoothly curved than the edge shape of the end surface a4 of the elastic sheet material 305a. This prevents the surface of the recording material P from rubbing strongly against the tip 303 of the guide member 305, thereby suppressing the generation of foreign matter such as paper dust and toner powder (collectively referred to as paper dust, etc.) due to friction with the tip 303. Therefore, this embodiment prevents streak-like noise from appearing in the read image due to paper dust, etc., adhering to the paper passing surface 302a of the reading glass 302, and thus suppresses the occurrence of reading errors by the inspection device 102, for example.

[0073] In particular, in this embodiment, the tip 303 of the guide member 305 is positioned so as to intrude into the nip line Ln, and the recording material conveyed along the nip line Ln easily rubs against the tip 303 of the guide member 305. Even with this configuration, the guide function of the guide member 305 can be maintained while preventing the generation of paper dust and the like due to rubbing against the tip 303. Furthermore, even when the paper passing surface 302a of the reading glass 302 is positioned so as to substantially coincide with the nip line Ln in order to improve reading accuracy, the generation of paper dust and the like due to rubbing against the tip 303 of the guide member 305, which protrudes from the paper passing surface 302a, can be prevented.

[0074] In this embodiment, the guide member 305 is formed by folding back the elastic sheet material 305a and adhering it with conductive double-sided tape 304. Because the guide member 305 has a conductive adhesive layer such as conductive double-sided tape, when particles such as charged paper dust adhere to the guide member 305, charges move within the adhesive layer due to electrostatic induction, and a charge that cancels the charge of the particles moves to a position opposite the particles. This makes it possible to electrostatically attract charged particles such as paper dust to the guide member 305 and make it difficult for them to accumulate on the paper passing surface 302a of the reading glass 302.

[0075] In this embodiment, the support member that supports the guide member 305 is made of a conductive metal plate 306, and the elastic sheet material 305a is adhered to the metal plate 306 with a conductive double-sided tape 304. That is, in this embodiment, at least a portion of the guide member 305 is conductive and electrically connected to the conductive support member. With this configuration, charged particles such as paper dust can be electrostatically attracted to the guide member 305, making it difficult for them to accumulate on the paper passing surface 302a of the reading glass 302. Note that instead of the conductive double-sided tape 304, the elastic sheet material 305a itself can be made of a conductive material. In addition, the metal plate 306 can be connected to ground potential via the frame (metal frame) of the inspection device 102.

[0076] In this embodiment, the guide member 305, which is disposed on the same side as the reading glass 302 with respect to the recording material conveyance path (the space through which the sheet passes) in the vertical direction D2, is formed of an elastic sheet material 305a. Alternatively, a guide member (e.g., the opposing guide 307) on the opposite side of the recording material conveyance path (the space through which the sheet passes) from the reading glass 302 may be formed of an elastic sheet material, with its tip end being a folded portion of the elastic sheet material. This can prevent paper dust and other particles from being generated at the tip end of the guide member. Because paper dust and other particles generated on the same side as the reading glass 302 are more likely to adhere to the reading glass 302, the configuration of this embodiment, in which the guide member 305 is formed of an elastic sheet material 305a, can more effectively prevent paper dust from adhering to the reading glass 302.

[0077] (Details of the second reading unit) Next, the second reading unit R2 and the guide member 311 provided in the second reading unit R2 will be described in detail with reference to Figures 5 and 6. Figure 5 is a view of the second reading unit R2 as seen in the sheet width direction, and Figure 6 is a view showing the state in which the recording material P passes through the second reading unit R2. Except for the positional relationship in the vertical direction D2 being reversed, the configuration of the second reading unit R2 is substantially the same as that of the first reading unit R1.

[0078] 5, the second reading unit R2 is provided with a guide member 311 made of an elastic sheet material 311a (sheet material, film material, first sheet material). The guide member 311 has a double-sided tape 310 attached to one surface of the elastic sheet material 311a, and is bonded to a metal plate 312 serving as a support member via the double-sided tape 310.

[0079] Here, the tip 309 of the guide member 311 is a folded portion formed by folding back a portion of the elastic sheet material 311a (a3) ​​so that it overlaps with another portion of the elastic sheet material 311a (a2). Specifically, the elastic sheet material 311a includes a first region a1 serving as a supported portion (base) supported (fixed) by the metal plate 312, a second region a2 extending downstream in the recording material conveyance direction D1 from the first region a1, and a third region a3 folded back relative to the second region a2. The third region a3 extends from the downstream end of the second region a2 in the recording material conveyance direction D1 to the upstream side in the recording material conveyance direction D1 and overlaps with the second region a2. Therefore, the tip 309 of the guide member 311 in this embodiment is a folded portion formed by folding back the third region a3 of the elastic sheet material 311a so that it overlaps with the second region a2.

[0080] The third region a3 of the elastic sheet material 311a is adhered to the second region a2 by the double-sided tape 310. This allows the guide member 311 to maintain the shape in which the elastic sheet material 311a is folded back. In other words, the end surface a4 of the elastic sheet material 311a is not exposed at the tip portion 309 of the guide member 311. This helps prevent the generation of paper dust, as will be described later. In addition, the double-sided tape 310 serves to adhere the guide member 311 to the metal plate 312 and to bond the second region a2 and the third region a3 of the guide member 311 together, thereby reducing costs. The end surface a4 is usually a cut surface formed by cutting the original sheet of the elastic sheet material 311a.

[0081] The elastic sheet material 311a is folded back so that the area including the end surface a4 (third area a3) is located behind the area not including the end surface a4 (second area a2) when viewed from the side of the space through which the recording material passes (the bottom side in the figure) in the vertical direction D2. In other words, the end surface a4 of the elastic sheet material 311a is located on the opposite side of the second area a2 of the elastic sheet material 311a from the space through which the recording material passes. This prevents the recording material being transported through the space from getting caught on the end surface a4 of the elastic sheet material 311a.

[0082] The elastic sheet material 311a and the double-sided tape 310 can be the same as the elastic sheet material 305a and the double-sided tape 304 of the first reading unit R1, but different materials may also be used. As an example, the elastic sheet material 311a is an ultra-high molecular weight polyethylene film with a thickness of 0.1 mm, a Young's modulus of 1.0 GPa, and a volume resistivity of 10^4 Ω·cm. The double-sided tape 310 is, for example, a 0.1 mm thick tape made of conductive aluminum foil.

[0083] The guide member 311 is disposed upstream of the reading position P2 in the recording material conveyance direction D1, and is disposed on the same side as the reading glass 308 with respect to the space through which the recording material passes in the vertical direction D2. The guide member 311 extends from a first region a1 supported by a metal plate 312 downstream in the recording material conveyance direction D1 and toward the side of the space through which the recording material passes in the vertical direction D2 (upper side in the drawing).

[0084] The length of the guide member 311 in the sheet width direction is set to be equal to or greater than the width of the paper passing surface 308a of the reading glass 308 in the sheet width direction. When the recording material is not being conveyed, the guide member 311 is arranged without contact with the reading glass 308, with a predetermined gap (for example, about 1 mm) between them. When viewed from the upstream side to the downstream side in the recording material conveyance direction D1, the guide member 311 covers at least a part (preferably the entirety) of the paper passing surface 308a of the reading glass 308.

[0085] A tip end 309 of the guide member 311 protrudes in the vertical direction D2 toward the space through which the recording material passes (downward in the drawing) further than the paper passing surface 308a of the reading glass 308. In particular, the tip end 309 of the guide member 311 protrudes in the vertical direction D2 toward the space through which the recording material passes, at least relative to an upstream end 308e of the paper passing surface 308a extending in the recording material conveyance direction D1.

[0086] Furthermore, the tip of the guide member 311 is intruding into the nip line Ln in the vertical direction D2, that is, the guide member 311 intersects with the nip line Ln.

[0087] An opposing guide 313 is disposed at a position facing at least a portion of the guide member 311 in the vertical direction D2. The opposing guide 313 faces the surface of the recording material opposite to the surface that contacts the guide member 311, and is a conveyance guide that guides the recording material into the gap between the reading glass 308 and the pressure roller 203. The opposing guide 313 extends downstream in the recording material conveyance direction D1 and toward the nip line Ln in the vertical direction D2. A tip 313a of the opposing guide 313 faces a paper passing surface 308a of the reading glass 308 in the vertical direction D2, upstream of the reading position P1 in the recording material conveyance direction D1. Unlike the guide member 311, the opposing guide 313 has rigidity such that deflection is negligible even when pressed by the recording material, and the tip 313a of the opposing guide 313 is positioned so that it does not enter the nip line Ln. The opposing guide 313 is made of, for example, the same stainless steel as the above-mentioned conveying guides (221, 222, 224, 225).

[0088] 6, when recording material P is conveyed to second reading unit R2, the recording material P is conveyed while contacting guide member 311. Here, when recording material P is not being conveyed, tip end 309 of guide member 311 protrudes in vertical direction D2 beyond paper passing surface 308a of reading glass 308. Therefore, recording material P is conveyed smoothly without getting caught on the edge portion of upstream end 308e of paper passing surface 308a of reading glass 308 or on upstream side surface 308b of reading glass 308.

[0089] Furthermore, because the guide member 311 is made of an elastic sheet material 311a, when pressed against the recording material P, the guide member 311 bends and the leading end 309 retreats to the position of the nip line Ln. This prevents the surface of the recording material P from rubbing strongly against the leading end 309 of the guide member 311.

[0090] Furthermore, in this embodiment, the tip 309 of the guide member 311 is formed by a folded portion of the elastic sheet material 311a. Therefore, the tip 309 has a curved surface that is more smoothly curved than the edge shape of the end surface a4 of the elastic sheet material 311a. This prevents the surface of the recording material P from rubbing strongly against the tip 309 of the guide member 311, thereby suppressing the generation of paper dust and other particles due to friction with the tip 309. Therefore, this embodiment prevents streak-like noise from appearing in the read image due to paper dust and other particles adhering to the paper passing surface 308a of the reading glass 308, and can suppress the occurrence of reading errors by the inspection device 102, for example.

[0091] In particular, in this embodiment, the tip 309 of the guide member 311 is positioned so as to intrude into the nip line Ln, and the recording material conveyed along the nip line Ln easily rubs against the tip 309 of the guide member 311. Even with this configuration, the guide function of the guide member 311 can be maintained while preventing the generation of paper dust and the like due to rubbing against the tip 309. Furthermore, even if the paper passing surface 308a of the reading glass 308 is positioned so as to substantially coincide with the nip line Ln in order to improve reading accuracy, the generation of paper dust and the like due to rubbing against the tip 309 of the guide member 311, which protrudes from the paper passing surface 308a, can be prevented.

[0092] In this embodiment, the guide member 311 is formed by folding back the elastic sheet material 311a and adhering it with conductive double-sided tape 310. Because the guide member 311 has a conductive adhesive layer such as conductive double-sided tape, when particles such as charged paper dust adhere to the guide member 311, charges move within the adhesive layer due to electrostatic induction, and a charge that cancels the charge of the particles moves to a position opposite the particles. This makes it possible to electrostatically attract charged particles such as paper dust to the guide member 311 and make it difficult for them to accumulate on the paper passing surface 308a of the reading glass 308.

[0093] In this embodiment, the support member that supports the guide member 311 is made of a conductive metal plate 312, and the elastic sheet material 311a is adhered to the metal plate 312 with a conductive double-sided tape 310. That is, in this embodiment, at least a portion of the guide member 311 is conductive and electrically connected to the conductive support member. With this configuration, charged particles such as paper dust can be electrostatically attracted to the guide member 311, making it difficult for them to accumulate on the paper passing surface 308a of the reading glass 308. Note that instead of the conductive double-sided tape 310, the elastic sheet material 311a itself can be made of a conductive material. In addition, the metal plate 312 can be connected to ground potential via the frame (metal frame) of the inspection device 102.

[0094] (Variation) In the above-described embodiment, the elastic sheet material 305a, 311a is folded back and overlapped only at the portions of the guide members 305, 311 that protrude from the metal plates 306, 312. This is not limiting, and for example, the entire guide members 305, 311 may be formed from the elastic sheet material 305a, 311a folded in half. In this case, the overlapping portions of the elastic sheet material 305a, 311a may be adhered (fixed) to the metal plates 306, 312 with double-sided tape or the like, and the folded-back portions may be positioned as the leading ends 303, 309 of the guide members 305, 311.

[0095] Furthermore, the printer 101 may be made to form a test image, and the execution conditions of the image forming operation in the printer 101 may be adjusted (image magnification correction, position correction, color correction, etc.) based on the image information read by the inspection device 102. In other words, the image reading device of this embodiment may be an adjustment unit for automatically adjusting the execution conditions of the image forming operation in the image forming system 100.

[0096] Second Embodiment In the first embodiment, an inspection device 102, which is an example of an image reading device, has been described, but the present technology can also be applied to image reading devices other than inspection devices. As a second embodiment, a configuration example in which the present technology is applied to a document reading device, which is another example of an image reading device, will be described.

[0097] Fig. 7 is a perspective view of the document reading device 400 according to this embodiment. Fig. 8 is a schematic diagram showing the cross-sectional configuration of the document reading device 400. The document reading device 400 includes a reader 420 and an ADF 401, and optically scans a document D to read image information. "ADF" stands for Auto Document Feeder. The document D is a sheet of paper such as printing paper or an envelope, a plastic film such as a sheet for an overhead projector, or cloth.

[0098] As shown in FIGS. 7 and 8, the document reading device 400 includes an image reading unit E including a first reading unit E1 that reads image information from a first side of a document D and a second reading unit E2 that reads image information from a second side of the document D. The ADF 401 includes a document tray 402, a discharge tray 403, a feed roller 404, a transport roller 405, a separation roller 406, pairs of transport rollers 408 and 409, a pair of discharge rollers 410, an inner structure 413, and an opening / closing cover 411. The feed roller 404, the transport roller 405, pairs of transport rollers 407 to 409, and the pair of discharge rollers 410 function as a conveying unit that conveys sheets. The ADF 401 is provided on the top surface of the reader 420 so as to be openable and closable. The opening / closing cover 411 is provided on the inner structure 413 so as to be openable and closable, and is capable of opening the document conveying path inside the ADF 401.

[0099] 8, the flow of the document reading operation, including the transport of document D from feeding to reading and discharge, will be described. Document D set in document tray 402 by the user is fed to transport roller 405 by the rotation of feed roller 404, which is a feeding means. Document D is transported while being separated one sheet at a time in the separation nip between transport roller 405 and separation roller 406, which is pressed against transport roller 405 by the biasing force of a spring member or the like. Document D that has passed through the separation nip is sent to image reading unit E by pair of transport rollers 407 and 408.

[0100] Then, while the document D passes through the reading positions of the first reading unit E1 and the second reading unit E2, the first reading unit E1 and the second reading unit E2 read image information from both sides of the document. After passing the reading positions, the document is delivered to the discharge roller pair 410 via the conveyance roller pair 409, and is discharged onto the discharge tray 403 by the discharge roller pair 410.

[0101] 9 is an enlarged view of image reading unit E. First reading unit E1 includes a reading unit 414 of a CIS type or the like, a reading glass 415 which is a transparent member, and an opposing member 425 which faces reading glass 415 across a space (gap) through which original D passes. Second reading unit E2 includes a reading unit 416 of a CIS type or the like, a reading glass 417 which is a transparent member, and an opposing member 427 which faces reading glass 417 across a space (gap) through which original D passes.

[0102] A guide member 418 of this embodiment is disposed upstream of the reading glass 417 and downstream of the reading glass 415 in the document transport direction D3 at the reading position of the reading unit 416. The guide member 418 is made of an elastic sheet material 418a and is supported by a support member 426.

[0103] The guide member 418 is a folded portion formed by folding back an elastic sheet material 418a so that a partial region (a3) ​​of the elastic sheet material 418a overlaps another partial region (a2). Double-sided tape 419 is attached to one side of the elastic sheet material 418a, and the overlapping regions (a2, a3) are adhered to each other via the double-sided tape 419. The guide member 418 is also adhered to a support member 426 via the double-sided tape 419. The double-sided tape 419 and the support member 426 are preferably made of a conductive material. Other details of the elastic sheet material 418a and the double-sided tape 419 can be the same as those described in the first embodiment.

[0104] Guide member 418 extends from support member 426 downstream in document conveyance direction D3 and toward a direction (upward in the figure) approaching paper passing surface 417a in vertical direction D4 perpendicular to paper passing surface 417a of reading glass 417. Tip 418b of guide member 418 covers upstream end 417e of paper passing surface 417a of reading glass 417.

[0105] Therefore, when document D is transported from first reading unit E1 to second reading unit E2, document D is guided by guide member 418 and transported smoothly without getting caught on the edge of upstream end 417e of paper passing surface 417a of reading glass 417. At this time, because guide member 418 is made of elastic sheet material 418a, guide member 418 bends when pressed by document D. Therefore, it is possible to prevent the surface of document D from rubbing strongly against tip end 418b of guide member 418.

[0106] Furthermore, in this embodiment, the tip 418b of the guide member 418 is formed by a folded portion of the elastic sheet material 418a. Therefore, the tip 418b has a curved surface that is more smoothly curved than the edge shape of the end face of the elastic sheet material 418a. This prevents the surface of the document D from rubbing strongly against the tip 418b of the guide member 418, thereby suppressing the generation of paper dust and other particles due to friction with the tip 418b. Therefore, this embodiment also suppresses streak-like noise in the scanned image caused by paper dust and other particles adhering to the paper passing surface 417a of the reading glass 417.

[0107] Although an embodiment in which the present technology is applied to a document reading device has been described above, a configuration similar to the internal configuration of the inspection device 102 described in the first embodiment may also be applied to a document reading device.

[0108] (Other embodiments) The present technology is not limited to the above-described embodiments, but can be applied to an image reading device that reads image information from a sheet, such as an image reading device that is built into an image forming apparatus (printer) and reads image information on a recording material on which an image is formed. [Explanation of symbols]

[0109] 202, 204... Reading means (reading unit) / 210, 220... Conveying means (pair of conveying rollers) / 302, 308... Transparent member (reading glass) / 303, 309... Tip of guide member / 304, 310... Adhesive layer (double-sided tape) / 305, 311... Guide member / 305a, 311a... Sheet material

Claims

1. A transparent member; a conveying means for conveying a sheet; a reading means for reading image information from the sheet conveyed by the conveying means through the transparent member; a guide member that is disposed upstream of a reading position where the reading unit reads image information from the sheet in a sheet conveying direction and that guides the sheet; and The guide member is formed of an elastic sheet material, The tip of the guide member is a folded portion where the sheet material is folded. An image reading device characterized by:

2. the guide member is disposed on the same side as the transparent member with respect to the space through which the sheet passes; 2. The image reading device according to claim 1, wherein:

3. the tip of the guide member protrudes further toward the space through which the sheet passes than the surface of the transparent member in a direction perpendicular to the surface of the transparent member extending along the sheet conveying direction; 3. The image reading device according to claim 2, wherein:

4. the conveying means includes a first roller pair disposed upstream of the reading position in the sheet conveying direction, and a second roller pair disposed downstream of the reading position in the sheet conveying direction, When viewed in a sheet width direction perpendicular to the sheet conveying direction, the transparent member is disposed on a first side of a nip line connecting a nip portion of the first roller pair and a nip portion of the second roller pair, When viewed in the sheet width direction in a state in which the guide member is not in contact with the sheet, a part of the guide member is supported by a support member on the first side with respect to the nip line, and the tip of the guide member protrudes beyond the nip line to a second side opposite to the first side.

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

5. the sheet material includes a first region supported by a support member, a second region extending from the first region to a downstream side in the sheet transport direction, and a third region extending from a downstream end of the second region in the sheet transport direction to an upstream side in the sheet transport direction and overlapping with the second region, The folded portion is a folded portion between the second region and the third region.

5. The image reading device according to claim 1, wherein the image reading device is a scanning device.

6. the third region includes an edge surface of the sheet material; the end surface is located on the opposite side of the second region of the sheet material from the space through which the sheet passes; 6. The image reading device according to claim 5, wherein:

7. an adhesive layer is provided on one surface of the sheet material; the first region of the sheet material is adhered to the support member by the adhesive layer; the second region and the third region of the sheet material are adhered to one another by the adhesive layer; 7. The image reading device according to claim 5, wherein the image reading device is a scanning device.

8. The adhesive layer is a conductive double-sided tape.

8. The image reading device according to claim 7, wherein:

9. At least a portion of the sheet material is electrically conductive.

9. The image reading device according to claim 1, wherein the image reading device is a scanning device.

10. Further, a conductive support member is provided to support the sheet material, At least a portion of the guide member is electrically conductive and is electrically connected to the support member.

10. The image reading device according to claim 9, wherein:

11. The volume resistivity of the sheet material is 10^3 Ω cm or more and 10^5 Ω cm or less.

11. The image reading device according to claim 8, wherein the image reading device is a scanning device.

12. The Young's modulus of the sheet material is 0.8 GPa or more and 1.2 GPa or less.

12. The image reading device according to claim 1, wherein the image reading device is a scanning device.

13. The transparent member is a first transparent member, the reading means is a first reading means, the guide member is a first guide member, and the sheet material is a first sheet material; a second transparent member disposed downstream of the first transparent member in the sheet conveying direction; a second reading means for reading image information from a surface of the sheet opposite to the surface from which the first reading means reads image information, through the second transparent member; a second guide member that is disposed downstream of a reading position where the first reading means reads image information from the sheet and upstream of a reading position where the second reading means reads image information from the sheet in the sheet conveying direction, and that guides the sheet; and and the second guide member is formed of a second sheet material having elasticity; a tip end of the second guide member is a folded portion where the second sheet material is folded; 13. The image reading device according to claim 1, wherein the image reading device is a scanning device.

14. an image forming means for forming an image on a recording material; an image reading device according to any one of claims 1 to 13, which reads image information from the recording material on which an image has been formed by the image forming means; An image forming apparatus comprising:

15. An image reading device according to any one of claims 1 to 13; an image forming means for forming an image on a recording material based on the image information read by the image reading device; An image forming apparatus comprising:

Images