JP5436792B2 - Sheet feeding apparatus and image reading apparatus - Google Patents

Description

  The present invention relates to a sheet feeding apparatus and an image reading apparatus, and in particular, includes a separation conveyance function for separating and conveying sheets one by one and a non-separation conveyance function for conveying the sheet while stopping the separation conveyance function. The present invention relates to a sheet feeding apparatus and an image reading apparatus that can be manually switched.

  In the conventional sheet feeding apparatus, the separation conveyance function for separating and conveying the sheets placed on the sheet placing table one by one to the conveyance path and the separation conveyance function for conveying the sheet that cannot be separated and conveyed are stopped. Some have a non-separation conveyance function for conveyance, and the two functions can be switched manually. In such a sheet feeding apparatus, switching between separation and non-separation is performed by the user based on the type of sheet to be conveyed. In other words, when a bundle of ordinary sheets is placed on the sheet mounting table, the separation and conveyance function is used to convey the sheets one by one while the separation and conveyance function is used. Place them one by one on the sheet mounting table and transport them using the non-separation transport function.

  On the other hand, in an image reading apparatus using a contact image sensor as an image reading means, the depth of field becomes shallow due to the characteristics of the lens. Therefore, the gap where the original sheet is conveyed between the platen roller or the like disposed at a position facing the contact image sensor and the contact image sensor is focused at the depth of field of the contact image sensor. It is set narrower than the matching range. If a sheet whose thickness is extremely thicker than the gap is conveyed, the glass surface of the contact image sensor may be damaged, and there is a possibility that the sheet will be clogged or the conveyance path may be broken. there were.

In order to prevent such a problem from occurring, an apparatus has been proposed in which the thickness of a sheet is detected during conveyance and sheet feeding is stopped when the thickness exceeds a reference value (see Patent Document 1).
JP 2000-255830 A

  However, in the above prior art, when the user mistakenly places the sheet bundle on the sheet placing table and starts the conveyance in the state switched to the non-separation conveyance function, the separation means does not function, so the sheet bundle is conveyed as it is. There is a risk that it will be transported to the path and the transport path will be destroyed.

  The purpose of Patent Document 1 is to detect the thickness of sheets separated and conveyed one by one using a sensor. Therefore, a sensor is provided on the downstream side of the separating unit, and if a bundle of sheets is placed in a state where the non-separating conveyance function is switched, the bundle of sheets is conveyed to that position. There is a possibility of destroying parts in the conveyance path.

  In addition, in an image reading apparatus having a conveyance path for conveying a sheet from top to bottom, when a sheet bundle is placed on the sheet placement portion in the non-separation mode in which the separation unit is disabled, the sheet bundle is directly placed on the conveyance path. Easy to enter.

An object of the present invention, in a state of switching to the non-isolation mode to disable separation means, be gone to start sheet feed conveying the sheet or sheet bundle user erroneously placed on the sheet placement table, transport An object of the present invention is to provide a sheet feeding apparatus and an image reading apparatus capable of controlling sheet feeding so that a path or the like is not broken.

To achieve the above Symbol purpose, the sheet feeding apparatus according to claim 1, wherein the conveying the sheet placing portion capable of mounting a bundle of sheets, the placed sheets in said sheet placement unit A sheet feeding unit that feeds and conveys the sheet, a separation unit that separates the sheets fed and conveyed by the sheet feeding unit one by one, a switching unit that invalidates the separation unit, and a sheet placement unit. Sheet thickness detection means for detecting the thickness of the placed sheet, and the sheet thickness detected by the sheet thickness detection means when the separation means is disabled by the switching means. The sheet thickness detecting means comprises: a control means for determining whether or not a predetermined value or less, and performing control based on a result of the determination; and a sheet detecting means for detecting a sheet placed on the sheet placing portion. Between the sheet detection means and the conveyance path The sheet detecting means has a lever and an optical sensor that are rotatably supported, and the lever has a leading end overlapping the tip of the lever of the sheet thickness detecting means. It is characterized by being installed.

According to the present invention, in a state of switching to the non-isolation mode to disable separation means, be gone to start sheet feed conveying the sheet or sheet bundle user erroneously placed on the sheet placement table, transport The sheet feeding can be controlled so that the road or the like is not broken.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic diagram showing a configuration of an image reading apparatus according to the first embodiment of the present invention.

  The image reading apparatus 100 includes an image reading apparatus main body 100a, a sheet placing portion 100b on which a bundle of sheets S can be placed between the ceiling portion 106, and a thickness of the sheet bundle placed on the sheet placing portion 100b. A sheet thickness detection unit 105 that detects the thickness.

  In addition, the image reading apparatus 100 reads the images of the front and back surfaces of the sheet S that is being conveyed on the conveyance path and the sheet feeding apparatus 100 c that feeds and conveys the sheet S placed on the sheet placement unit 100 b to the conveyance path. The image reading units 109 and 110 and the main motor 3 are provided. For the image reading units 109 and 110, CIS sensors that are contact image sensors are used.

  Furthermore, the image reading apparatus 100 discharges the platen rollers 109a and 110a arranged at positions facing the image reading units 109 and 110, and the sheet S on which an image is read by the image reading unit 109 and / or the image reading unit 110. A paper discharge roller pair 108 for paper is provided. The paper discharge roller pair 108 includes a driving roller 108a driven by the main motor 3 and a driven roller 108b.

  The sheet feeding device 100c includes a feeding roller 1 as a feeding rotating body that feeds and conveys a sheet placed on the sheet placing portion 100b, and a separation roller 2 that is configured by an elastic body and presses against the feeding roller 1. These are configured and driven by the main motor 3. The sheet feeding device 100c has a separating and conveying function (separating means) that conveys the sheets placed on the sheet placing portion 100b one by one to the conveying path by the feeding roller 1 and the separating roller 2. The separation / conveyance function is switched between valid and invalid according to an instruction from the user (switching means).

  FIG. 2 is a diagram illustrating a schematic structure of a driving portion of the sheet feeding device 100c in FIG.

  In FIG. 2, the gear group 34 is a gear group for transmitting the drive of the main motor 3. The drive gear 25 is connected to the gear group 34 and is connected to the shaft 5 a of the feed roller 1 via the one-way clutch 28 to drive the feed roller 1. The rotational force of the drive gear 25 is further transmitted to the shaft 6 a of the separation roller 2 by the gear 26 and the drive gear 27. As a result, the separation roller 2 is driven via the torque limiter 31 mounted inside the separation roller 2. The feed roller 1 rotates in the sheet conveying direction, while the separation roller 2 is driven to rotate in the direction opposite to the sheet conveying direction.

  The separation roller 2 is rotated (followed) in the sheet conveyance direction by the torque limiter 31 when there is no sheet S or when one sheet S is conveyed between the feed roller 1 and the separation roller 2. . When a plurality of sheets S are fed between the feed roller 1 and the separation roller 2, the separation roller 2 rotates in a direction opposite to the sheet conveying direction, thereby separating the sheets S one by one. It can be transported.

  The gear 26 is configured to be movable to a position where the rotational force of the drive gear 25 is not transmitted to the drive gear 27 by a lever (not shown). By not transmitting the rotational force of the drive gear 25 to the drive gear 27, the separation roller 2 is in a state of having no drive force. In the state where the sheet S is conveyed between the feed roller 1 and the separation roller 2, the separation roller 2 rotates following the operation of the sheet S, and the sheet S is conveyed without being separated. . This is called a non-separation transfer function. This non-separation transport function is suitable for transporting, for example, a laminate of two sheets, a sheet put in a clear file, or a half-folded sheet.

  FIG. 3 is a block diagram showing an electrical configuration of the image reading apparatus 100 of FIG.

  In FIG. 3, the image reading apparatus 100 includes a CPU 40, a RAM 41, a ROM 42, an image reading unit 43, a sensor unit 44, a drive unit 45, a display unit 46, and an operation unit 47. The CPU 40 controls each unit such as the image reading unit 43 and the sensor unit 44. The image reading unit 43 includes image reading units 109 and 110. The sensor unit 44 includes a sheet thickness detection unit 105 and the like. The drive unit 45 includes the main motor 3 and the like.

  The display unit 46 is composed of a liquid crystal or the like, and can display the state of the image reading apparatus 100 and the like. The operation unit 47 includes keys and buttons that accept operation instructions from the user. It should be noted that the display unit 46 and the operation unit 47 may be separate bodies or may be integrated like a touch panel.

  Next, the configuration of the sheet thickness detection unit 105 will be described.

  FIG. 4 is a schematic cross-sectional view of the periphery of the sheet thickness detection unit 105 in FIG. 5A and 5B are external views of portions constituting the sheet thickness detection unit 105 in FIG. 4. FIG. 5A shows a photo interrupter, and FIG. 5B shows a sheet thickness detection lever.

  As shown in FIG. 4, the sheet thickness detection unit 105 is installed on the wall surface of the sheet placement unit 100 b. The sheet thickness detection unit 105 includes a photo interrupter 103 that is an optical sensor, a sheet thickness detection lever 104 for detecting the sheet thickness, and a spring 107 biased by the sheet thickness detection lever 104.

  The sheet thickness detection lever 104 is rotatably supported by a bearing (not shown) around the rotation shaft 104b. The leading end 104a of the sheet thickness detection lever 104 protrudes from the wall surface of the sheet placing portion 100b into the space where the sheet S is placed. One end of the spring 107 is attached to the rear end of the sheet thickness detection lever 104 away from the front end 104a, the other end is attached to the image reading apparatus main body 100a, and the sheet S is placed on the front end 104a. Energizing force is applied in the direction protruding into the space.

  Further, the leading end 104a of the sheet thickness detecting lever 104 has a stopper 104c that allows the leading end 104a of the sheet placing unit 100b to have a predetermined width C between the ceiling 106 and the leading end 104a. The amount protruding from the wall is limited. Although not shown, the sheet placement unit 100b is provided with a reflective sensor as a sheet detection unit that detects that a sheet is placed on the sheet placement unit 100b.

  As shown in FIG. 5A, the photo interrupter 103 includes two slits 103 a and 103 b, and sends a predetermined signal to the CPU 40 when the sheet thickness detection lever 104 blocks between them. In response to a predetermined signal from the photo interrupter 103, the CPU 40 determines whether the thickness of the sheet placed on the sheet placement unit 100b is equal to or less than a predetermined value.

  Next, a sheet thickness detection method by the sheet thickness detection unit 105 will be described.

  FIG. 6 is a schematic cross-sectional view of the periphery of the sheet thickness detection unit 105 when the low-waist sheet S is placed on the sheet placement unit 100b, and FIG. FIG. 6 is a schematic cross-sectional view of a peripheral portion of a sheet thickness detection unit 105 when placed on the placement unit 100b. FIG. 8 is a schematic cross-sectional view of the periphery of the sheet thickness detection unit 105 when the sheet bundle is placed on the sheet placement unit 100b.

  The width C of the gap between the leading end portion 104a of the sheet thickness detection lever 104 and the ceiling portion 106 of the sheet placing portion 100b shown in FIG. 4 is substantially the same as the sheet thickness that the image reading apparatus 100 can feed and convey. ing. For example, when the sheet S placed on the sheet placement unit 100b is one or a plurality of sheets and is weak, the sheet S avoids the front end 104a of the sheet thickness detection lever 104 and is shown in FIG. It will be in such a state. Further, even when the sheet S placed on the sheet placement unit 100b is one sheet and is a stiff sheet or a thick sheet, the sheet S avoids the leading end 104a of the sheet thickness detection lever 104, and As shown in FIG.

  On the other hand, when a sheet bundle having a thickness larger than the width C of the gap is placed on the sheet placement portion 100b, the sheet thickness detection lever 104 is arranged at the leading end portion depending on the thickness of the bundle of sheets S as shown in FIG. 104a is pushed and rotates in the direction of arrow D around the rotation shaft 104b. When the sheet thickness detection lever 104a rotates, the rear end portion of the sheet thickness detection lever 104 reaches the position of the slits 103a and 103b of the photo interrupter 103 and blocks the optical path between the slits 103a and 103b. By configuring the sheet thickness detection unit 105 in this way, the CPU 40 can determine whether the sheets placed on the sheet placement unit 100b are bundles having a thickness exceeding the width C, or a single sheet or a plurality of small thicknesses. It is possible to determine whether the sheet bundle is about one sheet.

  Next, FIG. 9 illustrates an image reading operation when the user erroneously places the sheet bundle on the sheet placing unit 100b and starts image reading in the state where the non-separation mode in which the separation / conveyance function is disabled is switched. This will be described with reference to the flowchart of FIG.

  FIG. 9 is a flowchart illustrating an image reading operation of the image reading apparatus 100 according to the first embodiment.

  When the user gives an instruction to start scanning via a personal computer (PC) (not shown) connected to the image reading apparatus 100 (step S10), the CPU 40 performs separation with the current setting enabling the separation conveyance function. It is determined whether or not the mode is selected (step S11). As a result, when in the separation mode, the process proceeds to step S13. On the other hand, when the separation mode is invalid, that is, the non-separation mode in which the separation mode is switched to the non-separation conveyance function, the CPU 40 determines whether the thickness of the sheet or the sheet bundle detected by the sheet thickness detection unit 105 is equal to or less than a predetermined value. Is determined (step S12). The predetermined value is desirably the maximum sheet thickness that can be conveyed on the conveyance path.

  When the user mistakenly places a sheet or sheet bundle having a thickness exceeding a predetermined value on the sheet placement unit 100b in the state of switching to the non-separation mode, the CPU 40 makes the following determination. That is, the CPU 40 determines that the thickness of the sheet or the sheet bundle has exceeded a predetermined value from the detection result by the sheet thickness detection unit 105 (NO in step S12), and does not instruct the start of driving of the main motor 3. As a result, the sheet bundle is not conveyed. Then, an error indicating that the sheet bundle is placed in the non-separation mode is displayed on a PC (not shown) or the display unit 46 (step S16). Thereby, the user can easily recognize the error.

  On the other hand, when the thickness of the sheet or the sheet bundle is equal to or less than a predetermined value from the detection result by the sheet thickness detection unit 105, the CPU 40 determines that the sheet can be conveyed and drives the main motor 3 to convey the sheet. The start is instructed (step S13). When the main motor 3 starts to be driven, the feed roller 1 rotates and the sheet is conveyed from the sheet placement unit 100b to the conveyance path. At this time, the separation roller 2 is rotated with the sheet so as not to apply an extra load to the sheet. Thereafter, the sheet passes while being in close contact with the image reading units 109 and 110 by the platen rollers 109a and 110a. During this passage, image scanning is started, and an image formed on the front or back surface of the sheet is read by the image reading units 109 and 110 (step S14), and is output to the outside as an electrical signal. After the image is read, the sheet S is discharged to the outside by the discharge roller pair 108 (step S15).

  According to the first embodiment, the sheet thickness detection unit 105 detects the thickness of the sheet or sheet bundle placed on the sheet placement unit 100b when the separation conveyance function is disabled. Then, it is determined whether the thickness of the sheet is equal to or less than a predetermined value. As a result, it is possible to easily determine whether the sheet placed on the sheet placement unit 100b is a sheet or a sheet bundle having a thickness that cannot be conveyed. As a result, even if the user accidentally starts conveying a sheet bundle in the state where the separation unit is disabled, the conveyance path and parts in the conveyance path can be prevented from being destroyed. it can.

[Second Embodiment]
Next, an image reading apparatus according to a second embodiment of the present invention will be described. Note that portions overlapping with those of the image reading apparatus 100 in the first embodiment are denoted by the same reference numerals and description thereof is omitted, and only differences from the first embodiment will be described below.

  FIG. 10 is a schematic diagram showing the configuration of an image reading apparatus according to the second embodiment of the present invention.

  The image reading apparatus 200 shown in FIG. 10 is different from the image reading apparatus 100 shown in FIG. 1 in a sheet detection unit 205 that detects a sheet placed on the sheet placement unit 100b and a sheet thickness detection unit 105. It differs in that it includes a sheet thickness detection unit 206 installed at a position.

  The sheet detection unit 205 is installed on the wall surface of the sheet placement unit 100b. On the other hand, the sheet thickness detection unit 206 is installed on the wall surface of the ceiling 106 facing the sheet detection unit 205. As described above, the installation of the sheet detection unit 205 and the sheet thickness detection unit 206 at positions facing each other across the conveyance path has the following effects. That is, even if a sheet that cannot fully push the lever 11 of the sheet detection unit 205 such as a curled sheet or a thin sheet is placed, the sheet detection lever 11 of the sheet thickness detection unit 206 is pressed against the sheet detection lever 11 from the opposite surface. This makes it possible to reliably detect the sheet.

  Next, each configuration of the sheet detection unit 205 and the sheet thickness detection unit 206 will be described.

  FIG. 11 is a schematic cross-sectional view of the periphery of the sheet detection unit 205 and the sheet thickness detection unit 206 in FIG. 12 is an external view of a portion constituting the sheet detection unit 205 of FIG. 11, and FIG. 13 is an external view of a portion constituting the sheet thickness detection unit 206 of FIG.

  As shown in FIG. 11, the sheet detection unit 205 includes a photo interrupter 10, a sheet detection lever 11 for detecting the presence or absence of a sheet, and a spring 14 biased by the sheet detection lever 11. As shown in FIG. 12, the sheet detection lever 11 is rotatably supported by a bearing (not shown) around a rotation shaft 11c.

  The leading end portion 11a of the sheet detection lever 11 protrudes from the wall surface of the sheet placement portion 100b into a space where the sheet S is placed. The leading end portion 11a of the sheet detection lever 11 protruding from the wall surface of the sheet placing portion 100b is installed so as to overlap the leading end portions 13a and 13b of the sheet thickness detection lever 13, as shown in FIG. With this configuration, even when a curled sheet, a thin sheet, or the like is placed on the sheet placing portion, the sheet can be detected without escaping in the direction far from the sheet detecting lever 11. .

  One end of the spring 14 is attached to the rear end portion 11b of the sheet detection lever 11, the other end is attached to the image reading apparatus main body 100a, and the front end portion 11a protrudes into a space where the sheet S is placed. An energizing force is added. Further, the sheet detection lever 11 biased by the spring 14 does not block the optical path of the photo interrupter 10 when no sheet is placed on the sheet placement portion 100b. The spring 14 has a much weaker spring force than the spring 15 described later. Due to the difference in the spring force, the placed sheet is pressed toward the sheet detection sensor by the sheet thickness detection lever 13. It is supposed to be.

  As shown in FIG. 12, the photo interrupter 10 includes two slits 10 a and 10 b, and a predetermined signal is sent to the CPU 40 by the rear end portion 11 b of the sheet detection lever 11 blocking between them. When the sheet is placed on the sheet placement portion 100b, the leading end portion 11a of the sheet detection lever 11 is pushed by the sheet, so the sheet detection lever 11 rotates about the rotation shaft 11c in the direction of arrow A in FIG. . When the sheet detection lever 11 rotates in the direction of the arrow A, the rear end portion 11b reaches the positions of the slits 10a and 10b of the photo interrupter 10 and blocks the optical path between the slits 10a and 10b. As a result, the photo interrupter 10 sends a predetermined signal to the CPU 40.

  By configuring the sheet detection unit 205 as described above, the CPU 40 can detect that a sheet has been placed on the sheet placement unit 100b.

  As shown in FIG. 11, the sheet thickness detection unit 206 includes a photo interrupter 12, a sheet thickness detection lever 13 for detecting the sheet thickness, and a spring 15 biased by the sheet thickness detection lever 13. The As shown in FIG. 13, the sheet thickness detection lever 13 is rotatably supported by a bearing (not shown) around a rotation shaft 13d.

  The front end portions 13a and 13b of the sheet thickness detection lever 13 protrude from the wall surface of the ceiling portion 106 into a space where the sheet S is placed. The leading end portions 13a and 13b are provided at a distance so that the leading end portion 11a of the sheet detection lever 11 can be inserted between them.

  One end of the spring 15 is attached to the rear end portion 13c of the sheet thickness detection lever 13, and the other end is attached to the image reading apparatus main body 100a, and the front end portions 13a and 13b protrude into the space where the sheet S is placed. Energizing force is applied in the direction. The spring 15 is stronger than the spring 14 and presses the sheet in the direction in which the sheet detection unit 205 is installed. When the thickness of the sheet is equal to or less than the specified value, the sheet thickness detection lever 13 does not block the optical path of the photo interrupter 12.

  The photo interrupter 12 includes two slits 12a and 12b, and a predetermined signal is sent to the CPU 40 when the rear end portion 13c of the sheet thickness detection lever 13 blocks between the slits 12a and 12b. When the sheet is placed on the sheet placing portion 100b, the leading end portions 13a and 13b of the sheet thickness detecting lever 13 are pushed in accordance with the thickness of the sheet, so that the sheet thickness detecting lever 13 is centered on the rotating shaft 13d as shown in FIG. Rotate in the direction of arrow B.

  When the sheet thickness detection lever 13 rotates in the direction of arrow B, the rear end portion 13c reaches the position of the slits 12a and 12b of the photo interrupter 12, and blocks the optical path between the slits 12a and 12b. As a result, the photo interrupter 12 sends a predetermined signal to the CPU 40. The sheet thickness detection lever 13 is adjusted so as to block the optical path of the photo interrupter 12 for the first time when the thickness of the sheet or sheet bundle placed on the sheet placement unit 100b exceeds the transportable amount.

  By configuring the sheet thickness detection unit 206 as described above, the CPU 40 determines how thick the sheet placed on the sheet placement unit 100b is in accordance with a predetermined signal from the photo interrupter 103. can do.

  Next, FIG. 14 illustrates an image reading operation when the user erroneously places the sheet bundle on the sheet placing unit 100b and starts image reading in the state where the non-separation mode in which the separation / conveyance function is disabled is switched. This will be described with reference to the flowchart of FIG.

  FIG. 14 is a flowchart illustrating an image reading operation of the image reading apparatus 200 according to the second embodiment.

  When the user gives an instruction to start scanning via a PC (not shown) connected to the image reading apparatus 200 (step S10), the CPU 40 determines whether the current setting is a separation mode in which the separation conveyance function is enabled. Is determined (step S11). As a result, when in the separation mode, the process proceeds to step S13. On the other hand, when the separation mode is invalid, that is, in the non-separation mode in which the separation mode is switched to the non-separation conveyance function, the CPU 40 determines whether the sheet is placed on the sheet placement unit 100b by the sheet detection unit 205 ( Step S20).

  As a result of step S20, if the sheet detection unit 205 does not detect the sheet and the CPU 40 determines that no sheet is placed on the sheet placement unit 100b, an error is displayed on the PC or the display unit 46 (not shown) ( Step S21). Thereby, the user recognizes that the sheet is not placed on the sheet placement unit 100b.

  On the other hand, when the sheet detection unit 205 detects the sheet and the CPU 40 determines that the sheet is placed on the sheet placement unit 100b, the thickness of the sheet or the sheet bundle detected by the sheet thickness detection unit 206 is detected. It is determined whether it is below a predetermined value (step S12). This predetermined value is desirably the maximum sheet thickness that can be transported to the transport path, as in the first embodiment.

  When the user mistakenly places a sheet or sheet bundle having a thickness exceeding a predetermined value on the sheet placement unit 100b while switching to the non-separation mode in which the separation conveyance function is disabled, the CPU 40 The start of driving of the motor 3 is not instructed, and as a result, the sheet bundle is not conveyed. Then, an error indicating that the sheet bundle is placed in the non-separation mode is displayed on a PC (not shown) or the display unit 46 (step S22). Thereby, the user can easily recognize the error.

  On the other hand, if the thickness of the sheet or the sheet bundle is equal to or smaller than the predetermined value based on the detection result by the sheet thickness detection unit 206, the CPU 40 determines that the sheet can be conveyed and drives the main motor 3 to start conveying the sheet. (Step S13). When the main motor 3 starts to be driven, the feed roller 1 rotates and the sheet is conveyed from the sheet placement unit 100b to the conveyance path. At this time, the separation roller 2 is rotated with the sheet so as not to apply an extra load to the sheet. Thereafter, as in the first embodiment, when the sheet reaches the image reading units 109 and 110, image scanning is started (step S14), and the sheet is discharged by the discharge roller pair 108 (step S15).

  According to the second embodiment, the same effect as that of the first embodiment can be obtained. Further, the sheet detection unit 205 and the sheet thickness detection unit 206 are installed at positions facing each other across the conveyance path. As a result, even if a sheet such as a curled sheet or a thin sheet that cannot push the lever 11 of the sheet detection unit 205 is placed, the lever 13 of the sheet thickness detection unit 206 is moved from the opposite surface to the sheet detection lever 11. The sheet can be pressed and the sheet can be reliably detected.

  Note that the processing shown in FIG. 14 in the second embodiment may be applied to the first embodiment. In this case, the sheet placed on the sheet placing portion 100b is detected by a reflection type sensor (not shown).

  Further, the determination in step S20 in FIG. 14 may be performed before the determination in step S11. As a result, an error display can be performed when sheets are not stacked even in the separation mode.

  In the first and second embodiments, the case where the present invention is applied to an image reading apparatus has been described. However, the present invention is not limited to this and may be applied to a sheet feeding apparatus.

  Further, although the sheet thickness detection sensor is a lever type optical sensor, any switch element can be used. A plurality of sheet thickness detection sensors may be used. It is more preferable to use a sheet thickness detection sensor that can detect the sheet thickness in a multivalued manner using attenuation of ultrasonic waves or light.

  The object of the present invention can also be achieved by executing the following processing. That is, a storage medium that records a program code of software that realizes the functions of the above-described embodiments is supplied to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus is stored in the storage medium. This is the process of reading the code. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the program code and the storage medium storing the program code constitute the present invention.

  Moreover, the following can be used as a storage medium for supplying the program code. For example, floppy (registered trademark) disk, hard disk, magneto-optical disk, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD + RW, magnetic tape, nonvolatile memory card, ROM or the like. Alternatively, the program code may be downloaded via a network.

  Further, the present invention includes a case where the function of the above-described embodiment is realized by executing the program code read by the computer. In addition, an OS (operating system) running on the computer performs part or all of the actual processing based on an instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Is also included.

  Furthermore, a case where the functions of the above-described embodiment are realized by the following processing is also included in the present invention. That is, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, based on the instruction of the program code, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing.

1 is a schematic diagram illustrating a configuration of an image reading apparatus according to a first embodiment of the present invention. It is a figure which shows schematic structure of the drive part of the paper feeder in FIG. FIG. 2 is a block diagram illustrating an electrical configuration of the image reading apparatus in FIG. 1. It is a schematic sectional drawing of the peripheral part of the sheet | seat thickness detection part in FIG. FIGS. 5A and 5B are external views of portions constituting the sheet thickness detection unit of FIG. 4, where FIG. 5A shows a photo interrupter and FIG. FIG. 6 is a schematic cross-sectional view of the vicinity of a sheet thickness detection unit when a seatless sheet is placed on the sheet placement unit. FIG. 6 is a schematic cross-sectional view of the periphery of a sheet thickness detection unit when a strong sheet is placed on the sheet placement unit. FIG. 6 is a schematic cross-sectional view around a sheet thickness detection unit when a bundle of sheets is placed on the sheet placement unit. 3 is a flowchart illustrating an image reading operation of the image reading apparatus 100 according to the first embodiment. It is the schematic which shows the structure of the image reading apparatus which concerns on the 2nd Embodiment of this invention. It is a schematic sectional drawing of the peripheral part of the sheet | seat detection part and sheet thickness detection part in FIG. It is an external view of the part which comprises the sheet | seat detection part of FIG. It is an external view of the part which comprises the sheet | seat thickness detection part of FIG. 10 is a flowchart illustrating an image reading operation of the image reading apparatus 200 according to the second embodiment.

Explanation of symbols

40 CPU
46 Display unit 100 Image reading device 100b Sheet placement unit 100c Paper feeding device 103 Photo interrupter 104 Sheet thickness detection lever 105 Sheet thickness detection unit 107 Spring 109, 110 Image reading unit

Claims (7)

A sheet placement section capable of placing a bundle of sheets;
A sheet feeding unit that feeds and conveys a sheet placed on the sheet placing unit to a conveyance path;
Separating means for separating sheets fed and conveyed by the sheet feeding means one by one;
Switching means for invalidating the separating means;
Sheet thickness detecting means for detecting the thickness of the sheet placed on the sheet placing portion;
When the switching unit is disabled by the switching unit, it is determined whether or not the sheet thickness detected by the sheet thickness detection unit is equal to or less than a predetermined value, and control based on the determination result Control means for performing
Sheet detecting means for detecting a sheet placed on the sheet placing portion,
The sheet thickness detection means is installed at a position facing the sheet detection means across the conveyance path,
The sheet detecting means includes a lever and an optical sensor that are rotatably supported, and the lever is installed so that a tip portion thereof overlaps a tip of the lever of the sheet thickness detecting means. Sheet feeding device. It further comprises display means capable of displaying the state of the sheet feeding device,
Wherein, when the thickness of the sheet detected by the sheet thickness detecting means exceeds the predetermined value, the sheet feeding according to claim 1, wherein the displaying an error on the display unit device . 3. The sheet feeding device according to claim 1, wherein the control unit does not operate the sheet feeding unit when the thickness of the sheet detected by the sheet thickness detection unit exceeds the predetermined value. 4. Feeding device. The sheet thickness detecting means includes a lever that is rotatably supported, and the sheet placed on the sheet placing portion detects the thickness of the sheet by pushing and rotating the lever. The sheet feeding apparatus according to any one of claims 1 to 3 . The sheet thickness detecting means further includes an optical sensor, the sheet placed on the sheet placing portion pushes and rotates the lever, and the optical path of the optical sensor is blocked by the lever. The sheet feeding apparatus according to claim 4, wherein the thickness is detected. 6. The sheet feeding apparatus according to claim 4 , wherein the lever is installed so that a tip end portion of the lever protrudes from the sheet placing portion. Image reading apparatus comprising a sheet feeding apparatus according to any one of claims 1 to 6.

Images