JP2007192636A - Magnetic substance detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic substance detector, capable of determining whether to permit copy, for example, by attaching a magnetic substance to a detected object and detecting the magnetic field generated from the detected object. <P>SOLUTION: When a sheet material 32 is placed on an image forming device and a platen cover is closed, a detection section 40 starts to generate an alternating magnetic field from an exciting coil 12. Thus, when the magnetic substance 110 is attached to the sheet material 32, the magnetic substance 110 is magnetized by receiving the alternating magnetic field, and generates a magnetization pulse. The magnetization pulse is detected by generating an electromotive force in a detection coil 14 of the magnetic substance detector 10, and is detected by a detection circuit 121 of the detection section 40. The magnetic substance detector 10 is provided with a detection sensor 16 for detecting the existence of the sheet material 32. When the unprintable magnetic substance 110 is attached to the sheet material 32, a control section receives the results by the detection sensor 16 and detection section 40 and disables the printout operation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic body detection device that detects an object to be detected without contact.

  There are anti-copying printed materials for the purpose of preventing leakage of confidential information and personal information, and forgery prevention of securities. (Patent Document 1)

  On this copy-prevented printed matter, latent images having different reflectances and hues are formed. If this printing paper is copied with a copying machine, it will be difficult to copy due to the difference in reflectance and hue of the latent image formed on the printing paper, or the copying machine will be printed and illegal copying So that it can be recognized.

JP-A-7-76195

  However, this method requires a mechanism such as reading the printing paper or irradiating light from a predetermined direction in order to detect a latent image having a different reflectance or hue formed on the printing paper (object to be detected). Therefore, the apparatus configuration is complicated.

  In addition, when copying, there is a case where the printing paper (detected object) is copied while the printing paper (detected object) is a copy-preventing printed material without judging the presence or absence of the printing paper (detected object). May be recognized as an illegal copy, but may be copied to the extent that the content can be understood.

  In consideration of the above facts, the present invention provides a magnetic material to the object to be detected and detects a magnetic field generated from the object to be detected, for example, allowing the copying after detecting the presence or absence of the object to be detected. It is an object of the present invention to provide a magnetic body detection device that can determine whether or not.

  According to a first aspect of the present invention, there is provided a magnetic body detection device which is arranged in a planar shape, and is arranged in a planar shape with an excitation coil that magnetizes a magnetic body applied to an object to be detected and generates a magnetic field from the magnetic body. And a detection coil for detecting a magnetic field generated from the magnetic body, and a detection sensor for detecting the presence or absence of the object to be detected.

  According to the said structure, the exciting coil with which the magnetic body detection apparatus was equipped magnetizes the magnetic body provided to the to-be-detected object. The magnetic material is magnetized to generate a magnetic field, and this magnetic field is detected by the detection coil. For example, depending on whether or not a magnetic field is detected from a document by attaching the magnetic body detection device to a platen cover that presses a document that is a detection object placed on a platen glass that is a document table of a document reader. A system for determining whether or not to permit copying can be constructed.

  In addition, since the magnetic body detection device includes a detection sensor for detecting the presence or absence of an object to be detected, the detection sensor detects the original even if the platen cover is opened to read the original with the magnetic substance. Unauthorized copying can be prevented by constructing a system that does not permit copying when not.

  According to the magnetic body detection device of the present invention, a magnetic body is applied to the object to be detected, and a magnetic field generated from the object to be detected is detected. It is possible to determine whether or not to do so.

  A first embodiment of an image forming apparatus 30 in which the magnetic body detection device 10 of the present invention is employed will be described with reference to FIGS.

  In the first embodiment, a case where the image forming apparatus 30 is used to prevent unauthorized printing output or the like will be described as an example. However, the present invention is not limited to this.

  As shown in FIG. 4, the image forming apparatus 30 includes a platen glass 34 on which a sheet material 32 as an object to be detected is placed, and a platen cover 36 that covers the platen glass 34 so that it can be opened and closed. . Further, the platen cover 36 is provided with a magnetic body detection device 10 for detecting the magnetic body 110 (see FIG. 1) applied to the sheet material 32.

  In addition, a detection unit 40 is connected to the magnetic body detection device 10, and the detection unit 40 places the sheet material 32 on the platen glass 34 based on a detection signal from the magnetic body detection device 10. Whether or not the magnetic material 110 is applied to the sheet material 32 is recognized.

  In addition, a control unit 42 is connected to the detection unit 40, and the control unit 42 optically images the sheet material 32 placed on the platen glass 34 based on the recognition result of the detection unit 40. The operation of the image reading processing unit 44 that performs reading is controlled, and the operation of the image generation processing unit 46 that performs printing output of the image data read by the image reading processing unit 44 is controlled.

  As shown in FIG. 1, the detection unit 40 includes an excitation circuit 120 that performs control for generating a predetermined alternating magnetic field via an excitation coil 12 of a magnetic body detection device 10 to be described later. The excitation circuit 120 receives a predetermined alternating magnetic field generated from the excitation coil 12 by the magnetic body 110 applied to the sheet material 32, whereby the magnetic body 110 is magnetized and further a steep magnetic field that is a magnetic field generated at the time of magnetization reversal. Generate a pulse.

  This magnetic pulse is detected by the detection coil 14, and the detection circuit 121 takes in the detection signal detected by the detection coil 14 based on the timing of the reference signal output from the timing control unit 124, and stores it in the memory of the storage device (not shown). Store.

  In addition, the timing control unit 124 detects the time when the current value becomes 0 in the rising direction of the current generated by the excitation circuit 120, that is, the time when the current direction reverses from negative to positive, and the detected time Based on the above, a reference signal is output to the detection circuit 121 at a timing once in one cycle of the alternating magnetic field.

  In the detection signal stored in the memory, the alternating magnetic field component is removed by the signal processing unit 122, the positive signal component of the signal after the alternating magnetic field component removal is amplified to remove the noise component, and the magnetization of the magnetic body 110 A pulse signal corresponding to the inverted magnetic pulse is detected.

  The detection pulse signal detected by the signal processing unit 122 is output to the bit output unit 123. The bit output unit 123 converts the detection pulse signal into bit information expressed by a value of “1” or “0” based on the detection pulse signal. It outputs to the control part 42 of the image forming apparatus 30 shown in FIG.

  The bit output unit 123 expresses a value of “1”, for example, when the magnetic material 110 applied to the sheet material 32 is detected, and represents a value of “0”, for example, when it is not detected. Is output.

  Further, the detection unit 40 is provided with a sheet material detection unit 126 that detects a signal that the detection sensor 16 described later detects the presence or absence of the sheet material 32.

  On the other hand, as shown in FIG. 3A, the sheet material 32 is provided with a magnetic material 110 indicating that copying is not possible, and the magnetic material 110 is magnetized by applying a predetermined alternating magnetic field to the sheet material 32. A magnetic pulse, which is a magnetic field generated at the time of magnetization reversal, is detected via the detection coil 14 (see FIG. 1).

  The magnetic body 110 is an amorphous magnetic wire having a rectangular magnetic curve (BH curve) as shown in FIG. 3B, and the magnetic body 110 having such a magnetization curve is a magnetic body. By receiving an alternating magnetic field having a magnetic field strength exceeding the coercive force H1 inherent to 110, a steep magnetic pulse is emitted at the time of magnetization reversal. The characteristic of the so-called large Barkhausen effect is shown.

  In general, the intrinsic coercivity of the magnetic body 110 of the amorphous magnetic wire varies depending on the size and shape of the magnetic body 110, and the intensity of the magnetic pulse generated at the time of magnetization reversal according to the intrinsic coercivity of the magnetic body 110. Is also different.

  Using the characteristics of the magnetic body 110 of such amorphous magnetic wire, for example, if a plurality of types of magnetic bodies having different coercive force shapes and sizes are combined and applied to the sheet material 32, the sheet material 32 is uniquely identified. It can also be detected as information.

  Thus, the magnetic material 110 indicating that copying is not possible is applied to the sheet material 32, the sheet material 32 is placed on the platen glass 34 of the image forming apparatus 30 shown in FIG. 4, and the platen cover 36 is closed. Then, the magnetic body 110 applied to the sheet material 32 receives the alternating magnetic field generated from the exciting coil 12 shown in FIG. As a result, the magnetization of the magnetic body 110 is reversed, and a magnetic pulse due to the large Barkhausen effect is emitted at that time.

  As shown in FIG. 3, in addition to the alternating magnetic field waveform signal 401 in the detection signal waveform 402, the magnetic pulses are detection pulse signals A and B corresponding to the magnetic pulse generated when the magnetic body 110 is reversed in magnetization. .

  For example, the magnetic body 110 having the holding force H1 undergoes magnetization reversal when the magnetic field intensity becomes substantially H1 at the time t1 from the reference signal output from the timing control unit 124 (see FIG. 1). A steep magnetic pulse A is emitted.

  Further, when the magnetic field intensity of the waveform signal 401 becomes −H1 at time t2, the magnetic body 110 undergoes magnetization reversal from positive magnetization to negative magnetization, and at this time, a sharp magnetic pulse signal B is generated.

  The method of detecting the detection pulse signal based on the detection signal waveform 402 detected by the detection circuit 121 (see FIG. 1) described above is an example, and is not limited to this signal processing method. For example, the signal processing may be performed based on the pulse signal B, the signal processing may be performed by inverting one of the pulse signals A and B, and the signal may be processed based on both the pulse signals A and B. Various methods that can detect the detection pulse signal may be applied.

  Next, the configuration of the magnetic body detection device 10 used in the image forming apparatus 30 of the first embodiment will be described in detail.

  As shown in FIGS. 1 and 2, the magnetic body detection device 10 includes an exciting coil that generates an alternating magnetic field in a predetermined area range in order to magnetize the magnetic body 110 applied to the sheet material 32 that is the object to be detected. 12 and a detection coil 14 for detecting a magnetic pulse which is a magnetic field generated from the magnetic body 110 by the alternating magnetic field. The excitation coil 12 and the detection coil 14 are laminated in a planar shape on a flexible substrate 13 as an insulating layer.

  Further, on the plane on which the detection coil 14 is laminated in the flexible substrate 13, a cylindrical detection sensor 16 that detects the presence or absence of the sheet material 32 and a resistance member 22 that stabilizes the operation of the detection sensor 16 are the detection coil. 14 is implemented. Since the detection sensor 16 is mounted on the plane of the flexible substrate 13 without providing a recess or the like for attaching the detection sensor 16 to the flexible substrate 13, the structure is inexpensive. Further, since the detection sensor 16 is mounted on the side where the detection coil 14 is laminated, the presence / absence of the sheet material 32 on the detection coil 14 side and the magnetic field are efficiently detected.

  As an example of the detection sensor 16, it is conceivable to use an infrared reflective sensor that does not react to natural light.

  Further, the magnetic substance detection device 10 is provided with a protective sheet 18 that protects the detection coil 14. The protective sheet 18 has a teardrop shape (tears type) that does not have a corner as a detection window of the detection sensor 16. The opening 18A is provided. Since the shape of the opening 18A is a teardrop shape, when the sheet material 32 moves on the plane of the protective sheet 18, the sheet material 32 is not caught by the edge of the opening.

  Further, the thickness of the protective sheet 18 (including the adhesive layer) is made larger than the height of the detection sensor 16, and the detection sensor 16 mounted on the plane on the detection coil 14 side does not protrude from the opening 18A. It has a configuration. For this reason, the detection sensor 16 does not damage the sheet material 32.

  Next, the operation of the image forming apparatus 30 employing the magnetic body detection device 10 of the present invention will be described.

  As shown in FIGS. 1 and 4, when the sheet material 32 is placed on the platen glass 34 of the image forming apparatus 30 and the platen cover 36 is closed, the image reading processing unit 44 receives image data from the sheet material 32. Prior to reading, the control unit 42 activates the detection unit 40. With the activation of the detection unit 40, the excitation circuit 120 controlled by the timing control unit 124 of the detection unit 40 generates a predetermined alternating magnetic field from the excitation coil 12.

  This alternating magnetic field has a uniform magnetic field distribution in a plane on the platen glass 34. As a result, when the magnetic material 110 is applied to the sheet material 32 placed on the platen glass 34, the magnetic material 110 is magnetized by receiving an alternating magnetic field and generates a steep magnetization pulse at the time of magnetization reversal.

  In this way, when the magnetic body 110 emits a magnetic pulse, the magnetic pulse is detected by generating an electromotive force in the detection coil 14 of the magnetic body detection device 10 and detected by the detection circuit 121 of the detection unit 40. The

  The signal processing unit 122 of the detection unit 40 performs signal processing on the detection signal corresponding to the magnetic pulse emitted by the magnetic body 110 and the alternating magnetic field detected by the detection circuit 121.

  Further, the bit output unit 123 outputs the information on the magnetic body 110 applied to the sheet material 32 to the control unit 42 of the image forming apparatus 30 based on the information signal-processed by the signal processing unit 122.

  Further, the presence or absence of the sheet material 32 is detected by the detection sensor 16 mounted on the detection coil 14, and is detected by the sheet material detection unit 126 of the detection unit 40.

  For example, if the magnetic material 110 is applied to the sheet material 32, the control unit 42 receives the result from the detection unit 40 and disables the print output operation in the image generation processing unit 46.

  As described above, in the image forming apparatus 30 including the magnetic body detection device 10, the magnetic body detection device 10 is used to check the presence or absence of the magnetic body 110 before performing the copy processing operation of the sheet material 32 on the platen glass 34. When the sheet material 32 is detected, it is identified whether the sheet material 32 is copyable or non-copyable, and if it is determined that the document is non-copyable, control is performed not to execute the print output operation.

  On the other hand, when the platen cover 36 is opened and the non-copyable sheet material 32 is to be copied, the detection coil 14 cannot detect the magnetic field generated by the magnetic body 110, but the detection sensor 16 does not detect the sheet. Since the material 32 is not detected, the control unit 42 determines that the sheet material 32 cannot be copied and does not copy.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor. For example, in the above-described embodiment, the case where the magnetic body detection device 10 is disposed on the platen cover 36 has been described as an example. For example, the magnetic body detection device 10 is arranged along the document conveyance path of an automatic document feeding function (hereinafter referred to as ADF) instead of the platen cover 36. May be.

  Next, a second embodiment of the delivery product detection device 60 employing the magnetic material detection device 10 of the present invention will be described with reference to FIG.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 5, in this embodiment, as in the first embodiment, the magnetic body detection device 10 does not detect the sheet material placed on the platen glass of the image forming apparatus, but instead detects it. Instead, the configuration is such that the wrapping paper 62 </ b> A is detected as an object to be detected for wrapping the delivery product 62 carried by the belt conveyor 80.

  Specifically, the delivery product detection device 60 is provided with a magnetic material detection device 10, and a detection unit 40 is connected to the magnetic material detection device 10. Based on the detection signal of the detection coil of the magnetic body detection device 10, the detection unit 40 recognizes whether or not a magnetic body is applied to the wrapping paper 62 </ b> A that wraps the delivery product 62 on the belt conveyor 80. Further, the detection unit 40 detects how many delivery items 62 have been conveyed by the belt conveyor 80 based on the detection signal of the detection sensor of the magnetic body detection device 10.

  In addition, a management monitor 72 is connected to the detection unit 40, and information detected by the detection unit 40 can be displayed on the management monitor 72.

  For example, by using the wrapping paper 62A to which the magnetic material is applied to the delivery product 62 of company A that is handled strictly, even if the delivery product 62 of company A mixes with other delivery products, the delivery product detection device 60 Is used to detect the delivery product 62 of company A. As a result, the total number of delivery items carried by the belt conveyor 80 and the number of delivery items 62 of company A among them can be displayed on the management monitor 72.

  Next, a third embodiment of the image forming apparatus 200 in which the magnetic body detection device 10 of the present invention is employed will be described with reference to FIG.

  In addition, about the same member as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIG. 6, in this embodiment, as in the first embodiment, the magnetic body detection device 10 is attached to the platen cover in order to detect the sheet material placed on the platen glass of the image forming apparatus. Instead of being arranged, instead of being arranged, the sheet material 32 is fed to the first sheet feeding tray 202 and is placed facing the uppermost sheet material 32. Further, it is disposed on the mounting surface of the first discharge tray 206.

  More specifically, a first paper feed tray 202 and a second paper feed tray 210 that can be attached to and detached from the housing 204 are disposed in the lower part of the housing 204 of the image forming apparatus 200. Further, the first sheet feeding tray 202 is configured to feed the sheet material 32 to which the magnetic material 110 is applied, and sequentially pick up and convey the sheet material 32 by the pickup roll 208. Further, the first sheet feeding tray 202 is provided with the magnetic body detection device 10 facing the sheet material 32 fed to the first sheet feeding tray 202 and placed on the uppermost position. The sheet material 32 placed can be detected.

  In addition, a sheet material 212 to which the magnetic material 110 is not applied is fed to the second paper feed tray 210, and the sheet material 212 is sequentially taken out and conveyed by a pickup roll 208.

  Further, a transport roll 214 is disposed at a predetermined position in the housing 204 and constitutes a transport path 216 for transporting the sheet material 32 and the sheet material 212. In addition, guide members 252 are disposed on both sides of the transport path 216.

  In the middle of the conveyance path 216, the photosensitive drum 218 is disposed so as to be in contact with the sheet material 32 and the sheet material 212, and is rotated while being in contact with the sheet material 32 and the sheet material 212. The surface of the photosensitive drum 218 is charged by a charging device (not shown), and then a laser beam corresponding to image information is irradiated by the exposure device 220 to form an electrostatic latent image. The electrostatic latent image is developed (visualized) by supplying toner from the developing device 222.

  The photosensitive drum 218 is in close contact with the sheet material 32 and the sheet material 212 by sandwiching the sheet material 32 and the sheet material 212 with the transfer roll 224. As a result, the toner image on the photosensitive drum 218 is transferred to the sheet material 32 and the sheet material 212, and an image is formed on the sheet material 32 and the sheet material 212.

  A fixing device 226 is disposed on the downstream side of the photosensitive drum 218. The fixing device 226 is provided with a heating roll 226H and a pressure roll 226N. The sheet material 32 and the sheet material 212 are rotated by sandwiching the sheet material 32 and the sheet material 212 by these two rolls, and the toner is heated. Fix the image.

  A discharge roll 230 is disposed on the downstream side of the fixing device 226, and the sheet material 32 distributed by the gate 232 is discharged to the first discharge tray 206 disposed on the side surface of the housing 204. Further, a second discharge tray 242 and a third discharge tray 244 are provided below the first discharge tray 206, and the sheet material 212 distributed by the gate 232 and the gate 234 is discharged.

  Further, a scanner 240 is provided above the housing 204 so that image information formed on the sheet material can be read.

  Here, when the image information of the confidential document is read and copied by the scanner 240, the user inputs the confidential document to an operation unit (not shown) provided in the image forming apparatus 200. The control unit 250 receives an instruction that is a confidential document from the user, controls the gate 232 after conveying the sheet material 32 fed to the first paper feed tray 202 and forming an image on the sheet material 32. Thus, a copy of the confidential document is discharged to the first discharge tray 206.

  Further, when the sheet material 32 is unloaded from the first sheet feeding tray 202, whether or not the magnetic material 110 is applied to the sheet material by the magnetic body detection device 10 disposed above the first sheet feeding tray 202. When the magnetic material 110 is not applied based on this information, the control unit 250 is configured to stop copying. For this reason, the confidential document is reliably copied to the sheet material 32 to which the magnetic material 110 is applied, and is discharged to the first discharge tray 206.

  Further, since the magnetic material detection device 10 is provided in the first discharge tray 206, the magnetic material detection device 10 detects whether or not the sheet material 32 is placed on the first discharge tray 206. . Thus, when taking out a copy of the confidential document placed on the first discharge tray 206, the magnetic body detection device 10 detects that the sheet material 32 has been taken out, and the information of the magnetic body detection device 10 is used. The controller 250 generates a warning sound from a speaker (not shown). A user who is permitted to take out a copy of a confidential document removes the warning sound in a manner known only to the authorized user and then takes out the copy. For this reason, a user who is not permitted to take out a copy of a confidential document cannot release the warning sound, and this take-out is known.

  Further, since the confidential document is copied to the sheet material 32 to which the magnetic material 110 is applied, for example, by providing the magnetic material detection device 10 at the entrance / exit of an office, the confidential material is detected. Can be taken out.

  Note that when copying non-confidential documents by reading image information with the scanner 240, the user does not input that the document is a confidential document to the operation unit. After the fed sheet material 212 is conveyed and an image is formed on the sheet material 212, the gates 232 and 234 are controlled to discharge the copy to the second discharge tray 242 and the third discharge tray 244. It has a configuration.

  Accordingly, the confidential document is surely copied to the sheet material 32, and only authorized users can take it out of the image forming apparatus 200. Further, the magnetic material detecting device 10 is provided at the entrance / exit of the office. Thus, taking out confidential documents can be prevented.

It is the disassembled perspective view which showed the magnetic body detection apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which showed the magnetic body detection apparatus which concerns on 1st Embodiment of this invention. (A) It is a top view which shows the sheet material which concerns on 1st Embodiment of this invention. (B) It is a figure which shows the magnetic characteristic of the magnetic body provided to the sheet | seat material which concerns on 1st Embodiment of this invention. (C) It is a figure which shows the detection signal waveform detected by the detection circuit which concerns on 1st Embodiment of this invention. (D) It is a figure which shows the waveform of the detection pulse signal output from the signal processing part which concerns on 1st Embodiment of this invention. 1 is a schematic configuration diagram of an image forming apparatus in which a magnetic body detection device according to a first embodiment of the present invention is employed. It is explanatory drawing which showed the usage example of the delivery goods detection apparatus by which the magnetic body detection apparatus which concerns on 2nd Embodiment of this invention was employ | adopted. It is a schematic block diagram of the image forming apparatus by which the magnetic body detection apparatus which concerns on 3rd Embodiment of this invention was employ | adopted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic body detection apparatus 12 Excitation coil 13 Flexible board 14 Detection coil 16 Detection sensor 18 Protection sheet 18A Opening part 22 Resistance member 32 Sheet material (detected object)
62A Wrapping paper (object to be detected)
110 Magnetic material

Claims (6)

An excitation coil that is arranged in a planar shape, magnetizes a magnetic material applied to an object to be detected, and generates a magnetic field from the magnetic material;
A detection coil that is arranged in a planar shape and detects a magnetic field generated from the magnetic material;
A detection sensor for detecting the presence or absence of the detected object;
A magnetic substance detection device comprising:   The magnetic body detection device according to claim 1, wherein the excitation coil and the detection coil are stacked on a flexible substrate, and the detection sensor is mounted on the flexible substrate.   The magnetic body detection device according to claim 2, wherein a resistance member connected to the detection sensor and stabilizing the operation of the detection sensor is mounted on the flexible substrate.   The magnetic substance detection device according to claim 2, wherein the detection sensor does not protrude from a detection opening formed on a protective sheet that is bonded to the flexible substrate and protects the detection sensor.   The magnetic body detection device according to claim 2, wherein the detection sensor is mounted on the detection coil side.   6. The magnetic substance detection device according to claim 4, wherein the shape of the opening is a teardrop shape having no corners.

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