Image reading device

Abstract

To ensure identity of a document that has passed through a binding member detection unit and a document placed on a document placement unit.SOLUTION: An image reading device includes: reading units 41, 42 which read documents; a document placement unit 1 on which documents to be fed to the reading units 41, 42 are placed; a first document detection unit 51 which detects that the document is placed on the document placement unit 1; a binding member detection unit 20 which detects a binding member that binds the documents and is provided at a location different from the document placement unit 1; a second document detection unit which detects the passage of the document through the binding member detection unit 20; and a document identity determination unit 70 which determines whether the document detected by the first document detection unit 51 and the document detected by the second document detection unit are the same on the basis of a difference between detection timing by the second document detection unit and detection timing by the first document detection unit. If the document identity determination unit 70 determines that the documents are not the same, the reading units 41, 42 do not execute the reading processing.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image reading device that reads an image of a document. [Background technology]

[0002] When a document is transported while still bound with binding materials such as staples or clips, the document may be damaged or the transport path of the transport device may be damaged. Therefore, a method for detecting the binding materials before starting the paper feeding operation is required.

[0003] Conventionally, an image reading device has been proposed in which a binding material detection unit is provided on a side surface of a housing (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7000911 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is a problem in that it is not possible to guarantee that the document on which the binding material detection operation has been performed is the same as the document placed on the document stacking section. [Means for solving the problem]

[0006] In view of the above, an image reading device according to the present invention comprises: A reading unit that reads a document; a document stacking section for stacking documents to be fed toward the reading section; a first document detection unit that detects that a document has been placed on the document stacking unit; a binding material detection unit that detects a binding material that binds the document, the binding material detection unit being provided at a location different from the document stacking unit; a second document detection unit that detects passage of a document through the binding member detection unit; a document identity determination unit that determines whether the document detected by the first document detection unit and the document detected by the second document detection unit are identical based on a difference between a detection timing in the first document detection unit and a detection timing in the second document detection unit; Equipped with When the document identity determining section determines that the documents are not the same document, the reading section does not execute a reading process. Effect of the Invention

[0007] According to the present invention, in a configuration in which the binding material detection unit is located in a location different from the document stacking unit, it is possible to ensure that the document whose binding material detection unit has confirmed the presence or absence of a binding unit is identical to the document placed on the document stacking unit. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional side view that diagrammatically illustrates an image reading device according to a first embodiment; [Diagram 2] 1 is a schematic plan view, partially in perspective, of an image reading device according to a first embodiment; [Diagram 3] FIG. 1 is a perspective view illustrating an image reading apparatus according to a first embodiment. [Figure 4] FIG. 2 is a schematic cross-sectional view of a side view showing the configuration of a staple detection unit according to the first embodiment. [Diagram 5] FIG. 2 is a schematic view showing a configuration of a staple detection sensor according to the first embodiment. [Figure 6] 5 is a graph showing the relationship between the position of the staple and the resonance frequency according to the first embodiment. [Figure 7] 6 is a flowchart of staple detection control according to the first embodiment. [Figure 8] 5 is a flowchart of control for document identity confirmation according to the first embodiment. [Figure 9] 10 is a flowchart of control for document identity confirmation according to the second embodiment. [Figure 10] FIG. 13 is a perspective view illustrating a staple detection device according to a third embodiment. [Figure 11] FIG. 13 is a cross-sectional side view that illustrates a staple detection device according to a fourth embodiment. [Figure 12] 13 is an explanatory diagram of a coil shape of a staple detection sensor according to a fourth embodiment. FIG. [Figure 13] FIG. 13 is a front view illustrating a staple detection device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <First embodiment> First, the schematic configuration of an image reading device according to a first embodiment will be described with reference to FIGS.

[0010] [Image reader] The image reading device 200 includes a document transport device 101 that transports a document, and an image reading unit 40 that reads an image of the document transported by the document transport device 101. The document transport device 101 includes a document table 1 as a document stacking unit, a separation and feeding mechanism 10 as a separation and feeding means, a transport unit 30 as a transport means, and a staple detection unit 20 as a binding member detection means.

[0011] The document table 1 is a tray capable of holding a plurality of documents P. The width restriction plate 8 moves in the width direction of the document, i.e., in a direction perpendicular to the document transport direction, to restrict the widthwise position of the document. The separation and feeding mechanism 10 includes a feeding roller 11 as a feeding means, and a separation roller 12 as a separating member. The feeding roller 11 is driven to rotate by a feeding motor 13, and feeds the document in the direction of the arrow RT at a predetermined feeding speed. The predetermined feeding speed may be variable. For example, the predetermined feeding speed may be variable as appropriate depending on the type of document (thick paper, thin paper, plain paper, plastic sheet, etc.).

[0012] The separation roller 12 forms a nip portion N for nipping the document between itself and the feed roller 11, and separates the documents P loaded on the document table 1 one by one and feeds them by the feed roller 11. The nip portion N is an area where the separation roller 12 and the feed roller 11 are in contact with each other. The separation roller 12 constantly receives a rotational force from the separation motor 14 via a torque limiter (slip clutch) (not shown) that rotates in a direction to push the document back upstream in the document transport direction.

[0013] The feed motor 13 and the separation motor 14 start or stop driving in response to an instruction from a control unit 70 serving as a control means. The control unit 70 is also connected to a metal detection sensor 21 (described below) via a communication line (not shown), and controls the start or stop of driving of the feed motor 13 and the separation motor 14 based on the detection result of the metal detection sensor 21.

[0014] The control unit 70 controls the entire image reading device 200. Such a control unit 70 has a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU controls each part while reading a program corresponding to a control procedure stored in the ROM. In addition, working data and input data are stored in the RAM, and the CPU performs control by referring to the data stored in the RAM based on the above-mentioned programs, etc.

[0015] Dotted line D is a line indicating the center of the nip portion N between feed roller 11 and separation roller 12 in the document transport direction. When the leading edge of multiple documents transported by feed roller 11 reaches dotted line D, the documents come into contact with feed roller 11 and separation roller 12 and are separated one by one. The method of separating documents one by one by feed roller 11 and separation roller 12 will be described in detail below.

[0016] First, a description will be given of the case where one document is present between the feed roller 11 and the separation roller 12. The rotational force of the feed roller 11 in the direction of conveying the document downstream exceeds the upper limit value of the rotational force with which the separation roller 12 pushes the document back upstream via the torque limiter, and the separation roller 12 rotates following the feed roller 11.

[0017] Next, a case where there are multiple documents between the feed roller 11 and the separation roller 12 will be described. The separation roller 12 rotates in a direction that pushes the documents back upstream, pushing all documents except the bottommost document back upstream. In this way, when overlapping documents are fed into the nip portion N between the feed roller 11 and the separation roller 12, only the bottommost document is transported downstream due to the action of the feed roller 11 transporting the documents downstream and the action of the separation roller 12 pushing the documents back upstream. The other documents are pushed back upstream, and the overlapping documents are separated. Thus, the feed roller 11 and the separation roller 12 together form a document separation and feeding mechanism 10.

[0018] A feed roller 15 is disposed on the document loading surface of the document table 1 as a feed means. The feed roller 15 is driven to rotate by a feed drive motor (not shown) so as to feed the document in the same direction as the document feeding direction of the feed roller 11. In this embodiment, the feed roller 15 can be used as a pickup roller that feeds the lowermost document downstream. The feed motor 13 may be used as the feed drive motor. However, the feed roller 15 may be a roller disposed on the document table 1 that rotates in response to the movement of the document so as to assist the movement of the document.

[0019] As described above, by having the feeding roller 11 and the separation roller 12, the conveying device 101 of this embodiment separates and feeds the documents placed on the document table 1 one by one to the conveying path 90 at a predetermined feeding speed.

[0020] The conveying path 90 is formed between an upper conveying guide 91 and a lower conveying guide 92 by arranging the upper conveying guide 91 and the lower conveying guide 92 facing each other. A separation roller 12 is arranged in the upper conveying guide 91, and a feed roller 11 is arranged in the lower conveying guide 92.

[0021] Such a transport path 90 guides the document inside the device from the upstream side of the separation feeding mechanism 10 to the transport section 30. In this embodiment, the transport path 90 refers to the area between the most upstream side of the space sandwiched between an upper transport guide 91 and a lower transport guide 92 and a pair of transport rollers (transport roller pair) 33, 34 described below. The document fed by the separation feeding mechanism 10 as described above moves along the upper transport guide 91 or the lower transport guide 92 to a pair of transport rollers (transport roller pair) 31, 32 described below.

[0022] 1, the upper conveying guide 91 as a conveying guide forming the conveying path 90 has a first guide portion 91a and a second guide portion 91b. The first guide portion 91a is disposed along the conveying direction of the document conveyed in the conveying path (conveying passage) from the upstream side of the separation feeding mechanism 10 to the conveying roller 32. That is, the first guide portion 91a is disposed so as to be approximately parallel to the conveying direction of the document conveyed in the conveying path 90. The first guide portion 91a is disposed on the opposing side of the lower conveying guide 92 with a gap of about several mm (for example, 5 mm or less).

[0023] The second guide portion 91b is provided upstream of the first guide portion 91a in the document transport direction, and guides documents stacked on the document table 1 toward the first guide portion 91a. In this embodiment, the second guide portion 91b is inclined in a direction away from the documents as it moves further upstream from the upstream end of the first guide portion 91a in the document transport direction in order to arrange the document stack on the document table 1 so as to facilitate separation and feeding. In other words, the second guide portion 91b, which is the upstream portion of the upper transport guide 91, is inclined in a direction toward the lower transport guide 92 as it moves downstream in the document transport direction. Therefore, the second guide portion 91b is formed to be farther away from the lower transport guide 92 than the first guide portion 91a.

[0024] The dotted line C is a line indicating the boundary between the first guide portion 91a and the second guide portion 91b. The area where the dotted line C and the conveying path 90 in FIG. 1 and FIG. 2 intersect is an opening that is the entrance of the conveying path. The conveying path 90 on the downstream side is the conveying path, and the conveying path 90 on the upstream side is the feeding path. That is, the portion where the first guide portion 91a and the lower conveying guide 92 face each other is the conveying path, and the portion corresponding to the second guide portion 91b is the feeding path. In this embodiment, the first guide portion 91a and the second guide portion 91b are configured so that an integrated member is bent at the position where the upper conveying guide 91 intersects with the dotted line C, but the first guide portion 91a and the second guide portion 91b may be configured with different members.

[0025] A platen document detection sensor 51 is disposed as a first document detection unit on the upper conveying guide 91. The platen document detection sensor 51 is a sensor that detects documents loaded on the platen 1 or documents conveyed by the separation and feeding mechanism 10.

[0026] The transport section 30 has a pair of transport rollers 31, 32 that transport the document, and a pair of transport rollers 33, 34 that are disposed downstream in the document transport direction of the pair of transport rollers 31, 32 and similarly transport the document. The transport rollers 31 and 33 are driven to rotate by a transport motor 35, and the opposing transport rollers 32 and 34 are respectively driven to rotate. As a result, the document is transported downstream by each roller pair.

[0027] The conveying motor 35 is controlled by the control unit 70, and drives the conveying rollers 31 and 33 so that the conveying speed of the document can be changed according to settings such as the optimum speed for reading the document and the reading resolution. An image reading unit 40, which will be described later, is disposed between the pair of conveying rollers 31, 32 and the pair of conveying rollers 33, 34.

[0028] A post-registration sensor 5 is disposed downstream of the upstream pair of transport rollers 31, 32 and upstream of the image reading unit 40. The post-registration sensor 5 is a sensor that detects the document being transported.

[0029] The image reading section 40 has a pair of reading units 41, 42 that read the front and back sides of a document. The reading units 41, 42 are arranged opposite to each other across the transport path 90 along which the document is transported as described above, and read images on one or both sides of the document. The image reading section 40 can change the scanning interval based on the settings of the reading speed and resolution, and starts reading the image of the document immediately after the post-registration sensor 5 detects the document being transported.

[0030] The document, whose image has been read by the image reading unit 40, is transported by a pair of transport rollers 33, 34 and discharged onto the document discharge tray 6. The document discharge tray 6 is a tray on which the documents transported by the transport rollers 33, 34 to the rear end in the document transport direction are stacked.

[0031] As described above, the image reading device 200 separates and feeds the documents placed on the document table 1 one by one into the device, reads the images of the documents, and sequentially stacks the documents on the document discharge table 6 after the images have been read.

[0032] [Staple detection section] Next, the staple detection unit 20 as a binding material detection unit will be described with reference to Fig. 3 to Fig. 5. The binding material in this embodiment is assumed to be a metallic staple, and metal detection is used as the detection means.

[0033] As shown in FIG. 3, the staple detection unit 20 is composed of an upper staple detection unit 20a and a lower staple detection unit 20b, and is disposed on the side of the image reading device 200. Before loading an original on the document table 1, the user inserts an end of the original into the gap between the upper staple detection unit 21a and the lower staple detection unit 21b and slides it to check whether there is a metal binding at the end of the original. The method of detecting staples by the staple detection unit 20 will be described later, but the sliding direction is not important and may be along the dashed arrow MD or in the opposite direction. The original for which staple detection has been completed is loaded onto the document table 1.

[0034] The staple detection unit 20 includes a staple detection unit document detection sensor 61 as a second document detection unit, and is disposed in the staple detection unit upper portion 20a as shown in FIG. 4. When a user slides a document into the staple detection unit 20, the presence or absence of a document is detected. The staple detection unit document detection sensors 61a and 62b are provided at two locations on both ends so that the document can be detected whether the document is slid in the direction along the dashed arrow MD or the opposite direction. When the document is slid in the direction along the dashed arrow MD, the metal detection sensor 21 starts a metal detection operation after the staple detection unit document detection sensor 61a detects the document, and ends the metal detection operation when the staple detection unit document detection sensor 61b no longer detects the document. When the document is slid in the opposite direction to the arrow MD, the metal detection operation starts when the staple detection unit document detection sensor 61b detects the document, and ends the metal detection operation when the staple detection unit document detection sensor 61b no longer detects the document.

[0035] The staple detection unit 20 includes a metal detection sensor 21. The metal detection sensor 21 is disposed in the staple detection unit lower portion 20b as shown in FIG. 4. FIG. 5 shows the configuration of the metal detection sensor 21. The metal detection sensor 21 includes a detection coil 71, a resonance circuit 72, and a frequency calculator 73, and by connecting them on a printed circuit board, detects a staple that has entered a magnetic field (detection area) generated around the electrified detection coil 71. The frequency calculator 73 is connected to a control unit 70 that functions as a document identity determination unit by a communication line. The frequency calculator 73 may be connected to a SUB-CPU instead of the control unit 70, and the SUB-CPU may be connected to the control unit 70. By providing a SUB-CPU, it is possible to perform power saving operation by turning off the power supply of part of the control unit or lowering the operating frequency when performing metal detection operation.

[0036] The detector coil 71 is a coil formed of a conductor (pattern) such as copper foil on a printed circuit board. The number of turns of the detector coil 71 in this embodiment is set to a number that allows the detector coil 71 to resonate at about 300 kHz to 500 kHz when connected to the resonant circuit 72. The form of the detector coil 71 is not limited to the above, and it may be a coil formed by winding a conductor.

[0037] The resonant circuit 72 is a circuit that resonates by being connected to the detection coil 71. The resonant circuit 72 also includes a resonance capacitor not shown in Fig. 5. In general, the resonance condition between the detection coil 71 and the resonant circuit 72 is determined by the inductance component of the detection coil 71 and the capacitance component of the resonance capacitor.

[0038] The frequency calculator 73 is an IC that captures the periodic voltage change of the resonant circuit 72 at a preset time ts (sampling time) and calculates the resonant frequency of the connected resonant circuit 72. The frequency calculator 73 also converts the calculated frequency into digital data (frequency data) and outputs the frequency data.

[0039] The above sampling time ts has a minimum sampling time required to calculate the frequency once. The minimum sampling time is a specific value determined by the performance of the frequency calculator 73. The sampling time is determined by a register value inside the frequency calculator 73, and the register value can be changed by external communication, but a value at least equal to or greater than the minimum sampling time is set. Note that if the sampling time ts of the frequency calculator 73 is set to a short time, the calculated frequency will change significantly when the detection coil 71 is affected by external noise, so it is desirable to set the sampling time ts of the frequency calculator 73 to a long time.

[0040] The metal detection sensor 21 and the staple detection section document detection sensor 61 may be disposed in either the staple detection section upper part 20a or the staple detection section lower part 20b. The upper and lower parts may be interchanged, or the sensor may be disposed in only one of the upper and lower parts. There may be only one staple detection section document detection sensor 61, and it may be disposed near the center.

[0041] The following describes the characteristics of the resonance frequency that changes depending on the position of the staple S stapled to the document, with reference to FIG. 6. The horizontal axis represents the relative distance between the staple S and the detection coil 71, with the time when the staple detection unit document detection sensor 61 detects the document being set to 0. The vertical axis represents the resonance frequency calculated by the frequency calculator 73. Section A1 shows a state in which there is no staple S near the detection coil 71, and the resonance frequency shows a substantially constant frequency F1. Section A2 shows a state in which there is a staple S near the detection coil 71, and the resonance frequency of the resonance circuit 72 connected to the detection coil 71 drops due to electromagnetic induction generated between the staple S and the detection coil 71. Therefore, the resonance frequency calculated by the frequency calculator 73 drops from near frequency F1 to near frequency F2. Section A3 shows a state in which there is no staple S near the detection coil 71, and shows a frequency near F1 equivalent to that of section A1. In this way, the resonance frequency calculated by the frequency calculator 73 changes depending on the relative positions of the staple S and the detection coil 71.

[0042] The control unit 70 can determine that a staple is present when the frequency data changes to a value equal to or greater than a preset determination value. The preset determination value is the difference between the frequency F1 and the frequency F2. If the change in the frequency data is equal to or greater than the difference value, it is determined that a staple is present, and if the change is less than the difference value, it is determined that a staple is not present.

[0043] The determination value may be a value smaller than the difference value, for example, a predetermined percentage of the difference value, such as 50% or 70% of the difference value. That is, the determination value for determining that the frequency data has changed may be a value equal to or smaller than the difference value of the resonance frequency between the case where there is no staple passing through the detection area of ​​the detection coil 71 and the case where there is a staple, and equal to or larger than the fluctuation value Fc (FIG. 6) of the resonance frequency in a state where there are no staples around the detection area. By setting such a determination value in advance in the control unit 70, the control unit 70 determines the presence or absence of a staple approaching the vicinity of the detection coil 71.

[0044] Next, the metal detection operation of the staple detection unit 20 will be described as staple detection with reference to the flow chart of Fig. 7. When the power supply of the image reading device 200 is turned on, the control unit 70 starts staple detection.

[0045] The control unit 70 checks whether the staple detection unit document detection sensor 61 has detected a document (S101). If no document is detected (No in S101), the process returns to S101 and waits for detection of a document.

[0046] If a document is detected (Yes in S101), the staple check completion flag is cleared (S102). The staple check completion flag is a flag that indicates whether staple detection has been performed. If the flag is set, it has been performed, and if the flag is not set, it has not been performed.

[0047] Next, the staple flag is cleared (S103). The staple flag indicates whether or not the document has staples as a result of staple detection. If the flag is set, staples are present, and if the flag is not set, staples are not present.

[0048] Next, the measurement result of the timer T1 is cleared (S104). In this manner, in steps S102 to S104, the flag and the timer measurement result are cleared to avoid being affected by the result of the previous staple detection.

[0049] Next, it is confirmed whether the staple detection unit has detected metal (S105). If metal is detected (Yes in S105), a staple presence flag is set (S106).

[0050] Next, a warning that staples are present is displayed to the user (S107). Various warnings may be displayed on a display unit (not shown) of the image reading device, by turning on a display lamp (not shown), or by displaying on a screen of a computer connected to the image reading device.

[0051] The staple check completed flag is set (S108), and staple detection is completed.

[0052] On the other hand, if no metal is detected in S105 (No in S105), it is confirmed whether the staple detection unit no longer detects the document (S109). If a document is detected (No in S109), the process returns to S105 and metal detection is confirmed again.

[0053] When the document is no longer detected (Yes in S109), timer T1 starts to measure (S110). Timer T1 is a timer for measuring the time from when staple detection is completed until the document platen document detection sensor 51 next detects a document. Finally, a staple check completion flag is set (S108), and staple detection ends.

[0054] Next, the operation of confirming the identity of a document in this embodiment will be described with reference to the flowchart of Fig. 8. Note that the metal detection operation described in Fig. 7 and the document identity confirmation described in Fig. 8 proceed simultaneously.

[0055] 8, the control unit 70 starts document identity confirmation when the power of the image reading device 200 is turned on. The control unit 70 checks whether the document platen document detection sensor 51 has detected a document placed on the document platen (S201). If no document is detected (No in S201), the control unit 70 returns to S201 and waits for detection of the document.

[0056] If a document is detected (Yes in S201), it is confirmed whether the staple check completed flag is set (S202).

[0057] If the staple check completed flag is not set (No in S202), a warning such as "Isn't this an original that hasn't been staple-checked?" is displayed to the user (S203). Here, the user can select whether to perform the scan. If the user selects that scanning is possible (Yes in 204), wait for a scan instruction (S205). If a scan instruction does not come (No in S205), return to S205 and wait for a scan instruction. When a scan instruction comes (Yes in S205), perform the scan (S206) and end the original document identity confirmation.

[0058] If the user selects not to scan in S204 (No in S204), a message such as "Please remove the original from the document table" is displayed to the user (S207), and the original document identity confirmation is ended.

[0059] In S202, if the staple check completed flag is set (Yes in S202), check whether the timer T1 is less than the shortest time t1 (the first time), that is, whether T1 < t1 (S208). The timer T1 measures the time from after staple detection in S110 of FIG. 7. The shortest time t1 is a fixed value and is a short time when it is considered difficult to place the original on which staple detection has been performed on the document table 1. For example, it is set to 0.5 seconds. Even when an original is placed on the document table 1 first and then staple detection is performed on another original, T1 < t1. When the timer T1 < t1 (Yes in S208), since there is a possibility that the original on which staple detection has been performed and the original placed on the document table 1 are not the same, proceed to S203 and display a warning.

[0060] When the timer T1 is not <t1> (No in S208), it is checked whether the timer T1 has exceeded the maximum time t2 (the second hour), that is, whether T1 > t2 (S209). The maximum time t2 is a fixed value, and it is considered a long time such that too much time has passed to place the manuscript on which staple detection was performed on the platen 1. For example, it is set to 10 seconds. If the timer T1 > t2 (Yes in S209), since there is a possibility that the manuscript on which staple detection was performed and the manuscript placed on the platen 1 are not the same, the process proceeds to S203 and a warning is displayed.

[0061] When the timer T1 is not > t2 (No in S209), since the time from after staple detection is completed until the manuscript is placed on the platen 1 is appropriate, it is checked whether the staple present flag is set (S210). If the staple present flag is set (Yes in S210), a warning such as "Isn't this a manuscript without a staple?" is displayed to the user (S211), and the process proceeds to S204. If the staple present flag is not set in S210 (No in S210), the identity of the manuscript that passed through the staple detection unit 20 and the manuscript to be placed on the platen 1 can be confirmed, and since it has been confirmed that there is no staple either, it is considered that the scanning operation can be performed without problems, so the process proceeds to S205 and waits for a scan instruction. When a scan instruction comes (Yes in S205), scanning is performed (S206), and the manuscript identity confirmation is terminated.

[0062] Note that the staple detection operation in FIG. 7 and the manuscript identity confirmation operation in FIG. 8 are started triggered by the power of the image reading apparatus 200 being turned on. This may be started by the user pressing a detection start button (not shown), or may be started by a detection start instruction from a PC connected to the image reading apparatus 200. Until there is a user operation or a PC instruction, it becomes possible to configure to turn off the power of the platen manuscript detection sensor 51 and the staple detection unit 20 or reduce the operation frequency, and the power consumption can be reduced.

[0063] 8, if the platen document detection sensor 51 no longer detects a document or if the staple detection unit 20 detects a document, the flow chart of Fig. 8 may be reset and restarted from S201. In these cases, it is possible that the document passed through the staple detection unit 20 and the document placed on the platen are different documents.

[0064] As described above, in this embodiment, in a configuration in which the binding member detection unit is located in a different place from the document stacking unit, it is possible to ensure that the document for which the binding member detection unit has confirmed the presence or absence of a binding portion is identical to the document placed on the document stacking unit. In addition, if the identity of the document is in doubt, it is possible to prompt the user to check, and it is possible to avoid the document being damaged by mistakenly transporting a document with a binding member attached.

[0065] <Second embodiment> The second embodiment will be described. The configuration is the same as the first embodiment, and the flow of document identity confirmation in the first embodiment (FIG. 8) has been partially modified. There are two changes to the flow. The first is based on the assumption that after a document that has undergone staple detection is placed on the document tray, the user removes the document from the document tray to align it. If the time from removal to return is shorter than a certain time t3 (third time), the result of staple detection is considered valid, and if it is longer, it is considered that a different document may have been placed and a warning is issued. The second is that a warning is displayed to the user only after a scan instruction is received. Below, only the differences from the first embodiment will be described.

[0066] The operation of confirming the identity of an original in this embodiment will be described with reference to the flow chart of Fig. 9. When the power supply of the image reading device 200 is turned on, the control unit 70 starts confirming the identity of an original.

[0067] The control unit 70 checks whether the document table document detection sensor 51 has detected a document loaded on the document table (S301). If no document is detected (No in S301), the process returns to S301 and waits for document detection. If a document is detected (Yes in S301), it checks whether the staple check completed flag is set (S302).

[0068] If the staple check completed flag is not set (No in S302), it checks whether a scan instruction has been received (S303). The scan instruction may be received by the user pressing a scan instruction button (not shown) or by an instruction from a PC connected to the image reading device 200.

[0069] If no scan instruction is received (No in S303), the process returns to S301. If a scan instruction is received (Yes in S303), a warning "Isn't this a document without staple check?" is displayed to the user (S304). Here, the user can choose to continue or interrupt the scan operation.

[0070] If the user selects to continue (Yes in 305), scanning is performed (S306) and the document identity confirmation is terminated. If scanning is not selected (No in S305), the document identity confirmation is terminated without performing scanning.

[0071] In S302, if the staple check completed flag is set (Yes in S302), it checks whether the timer T1 is less than t1, that is, whether T1 < t1 (S307). The timer T1 measures the time elapsed since staple detection was completed in S108 of FIG. 7. t1 is a fixed value and is a short time considered to make it difficult to place the document on which staple detection was performed on the document table 1. For example, it is set to 0.5 seconds. Even if a document is first placed on the document table 1 and then staple detection is performed on another document, T1 < t1 will also hold.

[0072] When the timer T1 is <t1 (Yes in S307), since there is a possibility that the document on which staple detection was performed is not the same as the document placed on the document table 1, the process proceeds to S303 described above.

[0073] When the timer T1 is not <t1 (No in S307), it is checked whether the timer T1 exceeds t2, that is, whether T1>t2 (S308). t2 is a fixed value, and it is a long time considered that too much time has passed to place the document on which staple detection was performed on the document table 1. For example, it is set to 10 seconds.

[0074] When the timer T1>t2 (Yes in S308), since there is a possibility that the document on which staple detection was performed is not the same as the document placed on the document table 1, the process proceeds to S303 described above. When the timer T1 is not >t2 (No in S308), it is considered that the document on which staple detection was performed is the same as the document placed on the document table 1, and it is checked whether a scan instruction has come (S309).

[0075] When no scan instruction has come (No in S309), it is checked whether the document table document detection sensor 51 has stopped detecting the document placed on the document table (S310). This takes into account the case where the user removes the document once set on the document table in order to re-align it. If a certain time t3 is not exceeded, it is considered that the document is the same.

[0076] When the document table document detection sensor 51 has not detected no document (No in S310), the process returns to S309 to wait for a scan instruction. When no document is detected (Yes in S310), the measurement of the timer T3 is started (S311). The timer T3 is a timer for measuring the time from when the document table document detection sensor 51 detects no document until it detects a document again.

[0077] Next, the platen original document detection sensor 51 checks whether there is an original document. If there is no original document (No in S312), it waits until there is an original document. If there is an original document, it checks whether the timer T3 is less than t3, that is, whether T3 < t3 (S313). t3 is a fixed value and is longer than the time it is considered to take for the user to remove the original document once set on the platen, rearrange it, and then set it on the platen again. For example, it is set to 10 seconds.

[0078] If the timer T3 < t3 (Yes in S313), it is considered that the original document repositioned on the platen 1 is the same, and it checks whether a scan instruction has come (S309).

[0079] If the timer T3 is not less than t3 (No in S313), it checks whether a scan instruction has come (S314). If no scan instruction has come (No in S314), it returns to S314 and waits for the detection of the original document. If a scan instruction has come (Yes in S314), it displays a warning to the user, "Is it the same as the document with staple check?" (S315). Here, the user can choose to continue or interrupt the scan operation. Then, it proceeds to S305.

[0080] In S309, if a scan instruction has come (Yes in S309), it checks whether the staple present flag is set (S316). If the staple present flag is set (Yes in S316), it displays a warning to the user, "Isn't it a document with a staple?" (S317). Here, the user can choose to continue or interrupt the scan operation. Then, it proceeds to S305. If the staple present flag is not set (No in S316), since it can confirm the identity of the original document passing through the staple detection unit 20 and the original document placed on the platen 1 and can also confirm that there is no staple, it starts the scan (S306) and ends the original document identity confirmation.

[0081] In FIG. 9, the control unit 70 starts confirming the identity of the document when the power to the image reading device 200 is turned on. However, it may also be started by the user pressing a button (not shown), or by an instruction from a PC connected to the image reading device 200, or it may be started on the condition that the metal detection operation described in FIG. 7 has been completed.

[0082] 9, if the platen document detection sensor 51 no longer detects a document or if the staple detection unit 20 detects a document, the flow chart of Fig. 9 may be reset and restarted from S301. In these cases, the document passed through the staple detection unit 20 and the document placed on the platen may be different documents.

[0083] Furthermore, after the timer T3 starts counting in S311, if the timeout time t4 (fourth time) elapses without the document platen document detection sensor 51 indicating the presence of a document in S312, it is preferable to consider this as a timeout, reset the timer T1, and end the document identity confirmation.

[0084] As described above, in addition to Example 1, in this embodiment, a measure was taken for the case where the document is removed from the document platen for reasons such as aligning the document after the document is placed on the document platen after staple detection has been performed. If the time from removing the document to returning it is shorter than a certain period of time, the result of staple detection is considered valid, thereby making it possible to reduce the effort of redoing staple detection.

[0085] <Third embodiment> In the first and second embodiments, the staple detection unit 20 is disposed on the side of the image reading device 200. In this embodiment, an example is shown in which a staple detection device 300 is provided as a peripheral device instead of the staple detection unit 20, and is configured to be removable from the image reading device 200 and movable in position.

[0086] 10 shows a schematic configuration diagram of staple detection device 300. Staple detection device 300 is made up of staple detection device upper part 300a, staple detection device lower part 300b, staple detection device upper and lower connection part 300c, and staple detection device cable 300d.

[0087] The staple detection device upper part 300a has the same function as the staple detection section upper part 20a of the first embodiment, and the staple detection device lower part 300b has the same function as the staple detection section lower part 20b.

[0088] The staple detection device vertical connector 300c connects the staple detection device upper section 300a and the staple detection device lower section 300b. The vertical dimension of the staple detection device vertical connector 300c determines the gap between the staple detection device upper section 300a and the staple detection device lower section 300b, i.e., the thickness of the document stack for which staple detection is performed. The staple detection device vertical connector 300c may be configured to be expandable and contractible in the vertical direction so that the dimension of the gap can be changed.

[0089] The staple detection device cable 300d is connected to a staple detection device connection section 80 provided on the side of the image reading device 200. The staple detection device connection section 80 may be configured to be detachable by the user at will, and may be a connection form such as a USB connection. Also, it may be configured to be locked so that it cannot be separated once attached. The length of the staple detection device cable 300d determines the distance at which the staple detection device 300 can be placed away from the image reading device 200. The staple detection device may be configured to be bendable using a cable so that the user can place the staple detection device 300 at any position, or a hard member may be used to fix the relative positional relationship between the staple detection device 300 and the image reading device 200. The staple detection device connection section 80 is provided on the side of the image reading device 200, but may be provided, for example, on the back so as to be arranged alongside other power cables and interface cables, or may be provided on the opposite side according to the user's installation environment, or may be provided in multiple places.

[0090] As described above, by providing the staple detection device 300, the user can install the staple detection device at will. After the user purchases the image reading device 200, the user can additionally purchase the staple detection device 300 and add a staple detection function at will.

[0091] <Fourth embodiment> An image reading device according to the fourth embodiment of the present invention will be described below. In this embodiment, unlike the first to third embodiments, a staple detection unit 20 is disposed upstream of the sheet stacking tray 1. In the following, the same reference numerals are used for the parts common to the first embodiment, and the description will be omitted, and only the differences will be described.

[0092] 11 is a cross-sectional side view of the image reading device according to this embodiment. A detection coil 71 of the metal detection unit 20 is disposed on the sheet stacking platform 1. When a sheet P is placed upstream of the detection coil 71 in the transport direction and released, the sheet P slides down on the sheet stacking platform 1 at a speed Vf, and the entire sheet passes over the detection coil 71. The sheet stacking detection sensor 25 is a sensor that detects that the sheet P is stacked upstream of the detection coil 71 in the transport direction, and is configured, for example, by a reflective photocoupler.

[0093] The shape of the detector coil 71 wired on the printed circuit board will be described with reference to Fig. 12. The shape of the detector coil 71 is an oval shape that is long in the width direction that intersects (orthogonal in this embodiment) with the direction of the arrow RT, which is the sheet transport direction. The oval detector coil 71 is an oval shape with an outer diameter L2 in the longitudinal direction (width direction) that is extended as far as possible in the width direction of the sheet stacking table 1, and an outer diameter L1 in the lateral direction (arrow RT direction) that is equal to or greater than (speed Vf at which the sheet slides down) x (sampling time t).

[0094] That is, the outer diameter L1 of the detector coil 71 in the sheet conveying direction is equal to or greater than the length of the sheet sliding down at the speed Vf until the frequency calculator 73 calculates the resonance frequency at least once. More preferably, the size of the detector coil 71 in the sheet conveying direction is set to be greater than the length of the sheet sliding down at the speed Vf until the frequency calculator 73 calculates the resonance frequency at least once.

[0095] The outer diameter L1 is preferably set to a value when the sampling time t is the maximum value. That is, the outer diameter L1 is preferably set to a length equal to or greater than (the speed Vf at which the sheet slides down)×(the maximum sampling time t). In practice, taking into consideration the time constant of the eddy current caused by self-induction based on the electrical resistance of metals such as soft iron used for staples, the outer diameter L1 is preferably set to about (the speed Vf at which the sheet slides down)×(the maximum sampling time t)×1.5 to 2.0. In consideration of the accuracy of detecting the staple, it is preferable to use the resonance frequency in a state where the entire staple has entered within the range of the magnetic field generated by the detection coil 71, but when the staple has entered vertically (the long side has entered parallel to the conveying direction), it is most difficult to detect the staple. Taking this situation into consideration, it is preferable to set the outer diameter L1 of the detection coil 71 so that (L1-X) is equal to or greater than (the speed Vf at which the sheet slides down)×(the maximum sampling time t) when the length of the long side of the staple is X. This is because the outer diameter L1 is made larger than X, sampling is performed with the entire staple present within the detection coil 71, and sampling can be performed at least once within the range of the difference between the outer diameter L1 and X.

[0096] By thus defining the size of the detection coil 71 of the metal detection sensor 21 in the sheet conveying direction, the frequency calculator 73 can calculate the resonance frequency one or more times while the staple binding the sheets passes through the detection area. Therefore, frequency data when the staple approaches the vicinity of the detection coil 71 can be more reliably output to the CPU 74. In other words, metal such as staples binding the sheets being conveyed can be more reliably detected.

[0097] The shape of the detector coil 71 is not limited to the above-mentioned shape, and may be any shape as long as the outer diameter L1 is equal to or greater than the length of the sheet moving at the sliding speed Vf within the sampling time t of the frequency calculator 73. In other words, the shape of the detector coil 71 is not limited to the above-mentioned oval shape, and may be a rectangle with rounded corners, a rectangle, or a circle as long as the shape functions as a coil.

[0098] Next, the properties of the metal detection sensor 21 of this embodiment will be described below. The metal detection sensor 21 is a single-coil resonance type sensor that detects staples with one detection coil 71 each. That is, when viewed from a direction perpendicular to the sheet conveying surface, the metal detection sensor 21 is arranged so that at least a portion of the multiple detection coils do not overlap, and for example, one detection coil with multiple turns is arranged at the same location on the sheet conveying surface. Such a single-coil resonance type metal detection sensor can detect staples with one coil, but has the property that its sensitivity decreases when the staple moves away from the coil.

[0099] Next, the arrangement of the metal detection sensor 21 of this embodiment will be described below. As shown in FIG. 13, the detection coil 71 of the metal detection sensor 21 is arranged on the sheet stacking platform 1 at a predetermined interval from the dotted line D (nip portion N) on the upstream side in the transport direction. The predetermined interval is preferably equal to or greater than the length of the sheet P in the transport direction. For example, if the maximum standard size that can be loaded on the sheet stacking platform 1 is A4 size, the predetermined interval should be 297 mm or more. By arranging in this manner, the user places the sheet P upstream of the detection coil 71 in the transport direction, and when the user releases the sheet P, the sheet P slides down on the sheet stacking platform 1, so that the entire sheet passes over the detection coil 71, and metal can be detected for the entire sheet. The detection coil 71 and a cable connecting the metal detection sensor 21 and the CPU 74 are arranged inside the sheet stacking platform 1.

[0100] Even if the maximum standard size that can be loaded on the sheet stacking tray 1 cannot be secured as a predetermined interval due to dimensional constraints of the device, it is clear that a certain effect can be obtained, and therefore this does not deviate from the present invention. Note that, when a sheet slides down the sheet stacking tray 1, if the sheet does not slide down smoothly due to the frictional force or static electricity generated between the sheet P and the sheet stacking tray 1, a plurality of feed rollers 15 may be provided in the transport direction. [Explanation of symbols]

[0101] 1 Document holder 10 Separation feeding mechanism 11 Feeding roller 12 Separation roller 20 Staple detector 21 Metal detection sensor 30 Conveyor 40 Image reading unit 51 Document platen document detection sensor 61 Staple detection unit document detection sensor 70 Control section 71 Detection coil 72 Resonant circuit 73 Frequency Calculator 80 Staple detection device connection part 91 Upper transport guide (transport guide) 91a First guide section 91b Second guide part 92 Lower transport guide 101 Document transport device 200 Image reader 300 Staple detection device

Claims

1. A reading unit that reads a document; a document stacking section for stacking documents to be fed toward the reading section; a first document detection unit that detects that a document has been placed on the document stacking unit; a binding material detection unit that detects a binding material that binds documents, the binding material detection unit being provided at a location different from the document stacking unit; a second document detection unit that detects passage of a document through the binding member detection unit; a document identity determination unit that determines whether the document detected by the first document detection unit and the document detected by the second document detection unit are identical based on a difference between a detection timing in the first document detection unit and a detection timing in the second document detection unit; Equipped with 2. An image reading apparatus comprising: an original document identity determining unit that determines that the original documents are not the same, and that does not execute a reading process by the reading unit.

2. An image reading device as described in claim 1, characterized in that when the difference between the document detection timing by the first document detection unit and the document passage detection timing by the second document detection unit is smaller than a predetermined first time, the document consistency judgment unit judges that the document detected by the first document detection unit and the document detected by the second document detection unit do not match.

3. An image reading device as described in claim 2, characterized in that when the difference between the document detection timing in the first document detection unit and the document passage detection timing in the second document detection unit is greater than a second time that is greater than the first time and is set in advance, the document consistency judgment unit judges that the document detected by the first document detection unit and the document detected by the second document detection unit do not match.

4. 2. The image reading apparatus according to claim 1, further comprising a notification unit for notifying a user of the result of the determination by said document identity determination unit.

5. The image reading device according to claim 1, further comprising a selection means for selecting whether or not to perform a scanning operation when the document identity judgment unit determines that the document detected by the first document detection unit does not match the document detected by the second document detection unit.

6. The binding material detection unit detects the binding material by utilizing a magnetic field that changes with the movement of the binding material, a magnetic field detection control unit that receives a detection result of the document by the second document detection unit and a detection result of the binding material by the binding material detection unit, The image reading device according to claim 1, characterized in that the magnetic field detection control unit determines that a binding material is present when the binding material detection unit detects a change in the magnetic field while the second document detection unit is detecting the passage of a document.

7. 7. The image reading apparatus according to claim 1, wherein the binding member detection unit is configured to be detachable from the image reading apparatus.

Images