Apparatus for detecting performance of magnetic medium and method for detecting performance of magnetic medium

Abstract

The application provides a kind of detection device and detection method of magnetic medium performance, detection device includes: rotating assembly, rotating assembly is used to drive magnetic medium rotation;Magnetization component, magnetization component is located at the rotating circumference outside of rotating assembly, magnetization component is used to generate a plurality of magnetic field intensity different magnetization field, to when magnetic medium rotates to the magnetization range of magnetization component, magnetization component quantitatively magnetizes magnetic medium;Detection component, detection component is located at the rotating circumference outside of rotating assembly and is spaced apart from magnetization component, and when magnetic medium rotates to the detection range of detection component, detection component quantitatively detects the performance of magnetic medium and generates detection signal;In each rotating cycle of rotating assembly, magnetic medium successively passes through the magnetization of magnetization component and the detection of detection component, to complete the quantitative magnetization of magnetization component and the quantitative detection of detection component once.The application solves the problem that magnetic medium performance detection cannot be nondestructive quantitative detection in the prior art.

Description

Technical Field

[0001] This invention relates to the field of magnetic medium performance testing technology, and more specifically, to a device and method for testing the performance of magnetic media. Background Technology

[0002] Magnetic media are important information recording carriers; magnetic tapes and magnetic strips play a crucial role in information storage. Among the many properties of magnetic media, coercivity is a key aspect of performance testing. National standards "Identification Card Recording Technology Part 2: Magnetic Strips—Low Coercivity" and "Identification Card Recording Technology Part 6: Magnetic Strips—High Coercivity" clearly define the coercivity performance standards for magnetic stripe media. Traditional methods for testing the coercivity of magnetic media involve using a vibrating sample magnetometer or ferromagnetic analyzer. Due to limitations in the measurement principles of these instruments, this method requires cutting the magnetic media, typically to a size of 5mm or less, before placing it in a sample holder for quantitative testing. This method is not suitable for large-area magnetic media or for non-destructive testing of magnetic media.

[0003] Patents CN201180027867 and CN201780016531, among others, propose devices and methods for determining the coercivity characteristics of magnetic media by repeatedly magnetizing them with permanent magnets. Although these methods can perform non-destructive testing of coercivity characteristics without damaging the magnetic media, they can only qualitatively detect the magnitude of the coercivity of the magnetic media and cannot quantitatively detect its coercivity characteristics, let alone obtain accurate values ​​of the coercivity.

[0004] In other words, the existing technology for testing the performance of magnetic media cannot perform non-destructive quantitative testing. Summary of the Invention

[0005] The main objective of this invention is to provide a device and method for detecting the properties of magnetic media, so as to solve the problem that the performance of magnetic media cannot be detected quantitatively and non-destructively in the prior art.

[0006] To achieve the above objectives, according to one aspect of the present invention, a device for detecting the performance of a magnetic medium is provided, comprising: a rotating assembly for driving the magnetic medium to rotate; a magnetizing assembly located outside the rotation circumference of the rotating assembly, the magnetizing assembly generating multiple magnetizing fields with different magnetic field strengths, so that when the magnetic medium rotates to the magnetization range of the magnetizing assembly, the magnetizing assembly quantitatively magnetizes the magnetic medium; and a detection assembly without a built-in magnetic field, the detection assembly located outside the rotation circumference of the rotating assembly and spaced apart from the magnetizing assembly, the detection assembly quantitatively detecting the performance of the magnetic medium and generating a detection signal when the magnetic medium rotates to the detection range of the detection assembly; wherein, in each rotation cycle of the rotating assembly, the magnetic medium successively undergoes magnetization by the magnetizing assembly and detection by the detection assembly, thereby completing one quantitative magnetization by the magnetizing assembly and one quantitative detection by the detection assembly.

[0007] Furthermore, within different rotation cycles of the rotating component, the magnetic field strength of the magnetizing field is different, so that the magnetic medium has different magnetization states under the influence of coercive magnetic properties.

[0008] Furthermore, the rotating assembly includes a rotating cylinder, a magnetic medium is disposed on the surface of the rotating cylinder, and a magnetizing assembly is disposed at a distance from the rotating cylinder.

[0009] Furthermore, the magnetic medium is adhered to the surface of the rotating cylinder.

[0010] Furthermore, the surface of the rotating cylinder has an adsorption area with multiple adsorption holes, and air is drawn from inside the rotating cylinder to allow the magnetic medium to be adsorbed onto the adsorption area.

[0011] Furthermore, the rotating cylinder rotates at a constant speed.

[0012] Furthermore, the detection component includes a coil-type inductive magnetic head magnetic sensor; or the detection component includes a TMR magnetoresistive element, wherein the TMR magnetoresistive element has no built-in magnet.

[0013] Furthermore, the magnetization component includes an electromagnet.

[0014] Furthermore, the magnetization field is less than or equal to 10000 Oe.

[0015] According to another aspect of the present invention, a method for detecting the properties of a magnetic medium is provided, employing the aforementioned magnetic medium property detection device, comprising: magnetizing the magnetic medium and generating a detection signal through a detection component of the magnetic medium property detection device; determining the magnetization state of the magnetic medium by monitoring the change pattern of the detection signal; and determining the coercive magnetic properties of the magnetic medium based on the magnetization state and the detection signal.

[0016] Furthermore, during the magnetization process of the magnetic medium and the generation of a detection signal by the detection component of the magnetic medium performance detection device, if the amplitude of the detection signal increases, it is determined that the magnetic medium is in a positive magnetization state; if the amplitude of the detection signal remains unchanged, it is determined that the magnetic medium is in a saturated magnetization state; if the amplitude of the detection signal decreases, it is determined that the magnetic medium is in a negative magnetization state.

[0017] Furthermore, in the process of determining the coercive magnetic properties of a magnetic medium based on its magnetization state and detection signal, if the magnetic medium changes from a positive magnetization state to a saturated magnetization state, then the critical magnetization field of the magnetized magnetic medium is determined to be a saturated coercive magnetization field; if the magnetic medium is in a negative magnetization state and the amplitude of the detection signal is zero, then the critical magnetization field of the magnetized magnetic medium is determined to be a remanent coercive magnetization field.

[0018] Furthermore, during the process of magnetizing the magnetic medium and generating a detection signal through the detection component of the magnetic medium performance detection device, the magnetization component of the detection device is controlled to generate a magnetization field with an interval and monotonically changing magnetic field strength.

[0019] Furthermore, during the process of magnetizing the magnetic medium and generating a detection signal through the detection components of the magnetic medium performance detection device, the positive interval of the magnetic field strength of the magnetization field increases.

[0020] Furthermore, the method for detecting the performance of magnetic media also includes a first preprocessing step before the process of magnetizing the magnetic media and generating a detection signal through the detection component of the magnetic media performance detection device. The first preprocessing step includes: demagnetizing the magnetic media; and after the first preprocessing step is completed, during the process of magnetizing the magnetic media and generating a detection signal through the detection component of the magnetic media performance detection device, the magnetic field strength of the magnetization field is controlled to satisfy the positive interval increase by controlling the state of the magnetization component.

[0021] Furthermore, during the process of magnetizing the magnetic medium and generating a detection signal through the detection components of the magnetic medium performance detection device, the magnetic field strength of the magnetizing field increases in opposite directions.

[0022] Furthermore, the method for detecting the performance of magnetic media also includes a second preprocessing step before the process of magnetizing the magnetic media and generating a detection signal through the detection component of the magnetic media performance detection device. The second preprocessing step includes: saturating the magnetic media with magnetization; and after the second preprocessing step is completed, during the process of magnetizing the magnetic media and generating a detection signal through the detection component of the magnetic media performance detection device, the magnetic field strength of the magnetization field is controlled to satisfy the reverse interval increase by controlling the state of the magnetization component.

[0023] Furthermore, the method for detecting the properties of magnetic media includes at least the following steps: Step S11: controlling the magnetization field to be at the initial magnetic field strength and recording it; Step S12: controlling the rotating cylinder of the rotating component of the magnetic media performance detection device to rotate one revolution, so that the magnetic media passes through the magnetization range and the detection range successively, and recording the detection signal; Step S13: controlling the magnetic field strength of the magnetization field to change once and recording it; Step S14: repeating steps S12 and S13 until the amplitude of the detection signal remains unchanged or the amplitude of the detection signal decreases to zero.

[0024] By applying the technical solution of this invention, the magnetic medium performance detection device can generate a magnetizing field for quantitative magnetization of the magnetic medium 40. The magnetic medium 40 will be magnetized to different states according to its different coercive magnetic properties. The detection component 30 of the magnetic medium performance detection device can quantitatively detect the signal magnitude of the magnetic medium, thereby realizing the quantitative detection of the coercive magnetic properties of the magnetic medium. The magnetic medium performance detection method provided by this invention does not require the magnetic medium 40 to be sampled for detection during the detection process. It is suitable for non-destructive detection of the performance of large-area magnetic medium 40 and has great advantages over the current destructive sampling magnetic medium performance detection methods. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 A schematic diagram of a magnetic medium performance testing device according to an optional embodiment of the present invention is shown;

[0027] Figure 2 A flowchart illustrating a method for detecting the performance of magnetic media according to any optional embodiment of the present invention is shown.

[0028] Figure 3 A partial flowchart of a method for detecting the performance of a magnetic medium according to an optional embodiment of the present invention is shown.

[0029] Figure 4 A schematic diagram showing the change of the detection signal in Embodiment 1 of the present invention is shown;

[0030] Figure 5 A schematic diagram of the change in the detection signal in Embodiment 2 of the present invention is shown.

[0031] The above figures include the following reference numerals:

[0032] 10. Rotating assembly; 11. Rotating cylinder; 20. Magnetizing assembly; 30. Detection assembly; 40. Magnetic medium. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0035] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0036] To address the problem that the performance testing of magnetic media in existing technologies cannot be performed non-destructively, this invention provides a device and a method for testing the performance of magnetic media.

[0037] like Figures 1 to 5 As shown, the magnetic medium performance testing device includes a rotating component 10, a magnetizing component 20, and a detection component 30. The rotating component 10 drives the magnetic medium 40 to rotate. The magnetizing component 20 is located outside the rotation circumference of the rotating component 10 and generates multiple magnetization fields with different magnetic field strengths. When the magnetic medium 40 rotates into the magnetization range of the magnetizing component 20, the magnetizing component 20 quantitatively magnetizes the magnetic medium 40. The detection component 30 has no built-in magnetic field. The detection component 30 is located outside the rotation circumference of the rotating component 10 and is spaced apart from the magnetizing component 20. When the magnetic medium 40 rotates into the detection range of the detection component 30, the detection component 30 quantitatively detects the performance of the magnetic medium 40 and generates a detection signal. In each rotation cycle of the rotating component 10, the magnetic medium 40 is successively magnetized by the magnetizing component 20 and detected by the detection component 30 to complete one quantitative magnetization by the magnetizing component 20 and one quantitative detection by the detection component 30.

[0038] By placing the magnetic medium 40 on the rotating assembly 10 and rotating with it, the magnetic medium 40 can pass through the magnetization range multiple times and be quantitatively magnetized multiple times by the magnetization assembly 20. Under the action of magnetization fields with different magnetic field strengths, the magnetic medium 40 has different magnetization states. The detection assembly 30 detects the magnetic medium 40 after each magnetization, and the changes in the obtained detection signal can reflect the magnetization state of the magnetic medium 40, thereby obtaining the required parameters about the magnetization field, and thus reflecting the performance of the magnetic medium 40. Using the magnetic medium performance detection device of this application, the integrity of the magnetic medium 40 does not need to be damaged, and the magnetic medium 40 can be directly placed on the rotating assembly 10, realizing non-destructive testing of the magnetic medium performance. In addition, the detection assembly 30 has no built-in magnetic field and will not further magnetize the magnetic medium 40, thus not affecting the test results. Furthermore, since the magnetization component 20 and the detection component 30 are on the same circumference and coaxial with the rotation component 10, it is possible to ensure that the magnetic medium 40 will be magnetized once by the magnetization component 20 and detected once by the detection component 30 when the rotation component 10 rotates once, thus ensuring the timeliness of the detection of the magnetic medium 40.

[0039] It should be noted that the detection component 30 and the magnetization component 20 do not affect each other and work independently. Therefore, the detection component 30 will not affect the magnetization effect of the magnetization component 20, and the magnetization component 20 will not affect the detection result of the detection component 30.

[0040] It should be noted that the magnetization range of the magnetization component 20 is radial, with the starting center of the radiation located at the point where the distance between the magnetization component 20 and the rotating component 10 is shortest. When one end of the magnetic medium 40 rotates to one side of the magnetization range, the magnetic medium 40 begins to be magnetized until the other end of the magnetic medium 40 leaves the other side of the magnetization range. The magnetization component 20 includes an existing magnetization device to determine the size of the magnetization range.

[0041] It should be noted that the detection range of the detection component 30 is radial, with the initial center of radiation located at the point where the distance between the detection component 30 and the rotating component 10 is shortest. When one end of the magnetic medium 40 rotates to one side of the detection range, the detection component 30 detects a signal, and the detection signal reaches its peak value when it reaches the position corresponding to the radiation center. When the entire magnetic medium 40 is within the detection range, the detection signal is zero. When one end of the magnetic medium 40 leaves the detection range and the other end rotates to the position corresponding to the radiation center, the detection signal drops to its minimum value. The detection signal returns to zero only after the other end of the magnetic medium 40 leaves the detection range. This completes one detection cycle. In other words, since the magnetic medium 40 has a certain length, the detection signal is not in the form of a pulse signal, but rather a sinusoidal signal broadened to a sinusoidal shape. The detection component 30 includes existing detection devices to determine the size of the detection range.

[0042] Specifically, the magnetic field strength of the magnetizing field varies within different rotation cycles of the rotating component 10, causing the magnetic medium 40 to have different magnetization states under the influence of its coercive magnetic properties. In other words, the magnetic field strength of the magnetizing field changes with each rotation of the rotating component 10, ensuring that the magnetic medium 40 is magnetized by different magnetic field strengths each time it passes through the magnetization range. Due to the influence of the coercive magnetic properties of the magnetic medium 40, its magnetization state differs under the influence of different magnetic field strengths. For example, the magnetizing component 20 generates several interval magnetizing fields H1, H2, H3..., which are used to magnetize the magnetic medium 40. The detection component 30 detects the signals of the magnetic medium after each interval magnetization field, corresponding to M1, M2, M3...

[0043] Specifically, the rotating assembly 10 includes a rotating cylinder 11, a magnetic medium 40 disposed on the surface of the rotating cylinder 11, and a magnetization assembly 20 disposed at an interval from the rotating cylinder 11. By directly disposing of the magnetic medium 40 on the surface of the rotating cylinder 11, non-destructive testing of the magnetic medium 40 is ensured, while also facilitating operation. The magnetic medium 40 can change position as the rotating cylinder 11 rotates, ensuring that a test can be performed after one magnetization.

[0044] Optionally, the magnetic medium 40 is adhered to the surface of the rotating cylinder 11 to ensure that the magnetic medium 40 is stably positioned on the rotating cylinder 11 and to prevent the magnetic medium 40 from falling off during rotation. For example, the magnetic medium 40 can be adhered to the rotating cylinder 11 using tape.

[0045] Alternatively, the rotating cylinder 11 can be configured with an adsorption area on its surface, containing multiple adsorption holes. Air can be extracted from inside the rotating cylinder 11 to allow the magnetic medium 40 to adhere to this adsorption area. This configuration allows the magnetic medium 40 to adhere to the surface of the rotating cylinder 11 due to the pressure difference between its interior and exterior surfaces after the air is extracted using a vacuum pump. This method eliminates the need for adhesive materials, thus avoiding any impact on the cleanliness of the magnetic medium 40's surface.

[0046] Specifically, the rotating cylinder 11 rotates at a constant speed, ensuring that the time interval between each magnetization and detection of the magnetic medium 40 is the same. This facilitates the setting of the changing period of the magnetization field generated by the magnetization component 20 and also facilitates the analysis of the detection signal. Preferably, the rotation speed is 75 r / min, which ensures that the detection component 30 acquires a stable detection signal.

[0047] Optionally, the detection component 30 includes a coil-type induction magnetic head magnetic sensor capable of sensing the detection signal of the magnetic medium 40.

[0048] Of course, the detection component 30 can also include a TMR magnetoresistive element. The TMR magnetoresistive element has no built-in magnet, which ensures the accuracy of the detection results and avoids the magnetic medium 40 being subjected to additional magnetization.

[0049] Specifically, the magnetization component 20 includes an electromagnet, which generates a magnetization field of a fixed magnitude. While ensuring the magnetization effect, the device is simple and has a lower manufacturing cost.

[0050] Specifically, the magnetization field is less than or equal to 10000 Oe, which can meet the saturation magnetization requirements of current high coercivity magnetic media samples.

[0051] like Figure 2 As shown, the present invention also provides a method for detecting the properties of a magnetic medium, employing the aforementioned magnetic medium performance detection device, comprising: magnetizing the magnetic medium 40 and generating a detection signal through the detection component 30 of the magnetic medium performance detection device; determining the magnetization state of the magnetic medium 40 by monitoring the change pattern of the detection signal; and determining the coercive magnetic properties of the magnetic medium 40 based on the magnetization state and the detection signal. By quantitatively magnetizing and detecting the magnetic medium 40, detection signals are obtained under different quantitative magnetization states of the magnetic medium 40, and the magnetization state of the magnetic medium 40 is determined by the change pattern of the detection signal, so as to obtain the coercive magnetic properties of the magnetic medium 40 using the magnetization state and the detection signal.

[0052] Specifically, during the magnetization process of the magnetic medium 40 and the generation of a detection signal by the detection component 30 of the magnetic medium performance detection device, if the amplitude of the detection signal increases, the magnetic medium 40 is determined to be in a positive magnetization state; if the amplitude of the detection signal remains unchanged, the magnetic medium 40 is determined to be in a saturated magnetization state; and if the amplitude of the detection signal decreases, the magnetic medium 40 is determined to be in a negative magnetization state. By utilizing the changes in the amplitude of the detection signal, the magnetization state of the magnetic medium 40 at a certain stage can be determined.

[0053] It should be noted that the amplitude of the detection signal will not remain unchanged when the magnetic medium 40 is in a forward magnetization state or a reverse magnetization state. Therefore, if the amplitude of the detection signal remains unchanged, it can be determined that the magnetic medium 40 is in a saturated magnetization state.

[0054] It should be noted that in actual operation, when the magnetic medium 40 is in a saturated magnetization state, the amplitude of the detection signal may fluctuate slightly within the allowable error range. However, this still falls under the case where the amplitude of the detection signal remains unchanged as described above. That is, within the allowable error range, a slight fluctuation in the amplitude of the detection signal does not affect the judgment that the magnetic medium 40 is in a saturated magnetization state.

[0055] It should be noted that the three magnetization states—positive magnetization, saturation magnetization, and reverse magnetization—describe the magnetization state of the magnetic medium 40 within a certain stage. The magnetic medium 40 actually possesses multiple different quantitative magnetization states within this stage. For example, if the magnetic medium 40 undergoes multiple quantitative magnetizations with different magnetic field strengths, resulting in multiple different quantitative magnetization states, and the amplitude of the detected signal increases progressively, then it is determined that the magnetic medium 40 is in a positive magnetization state at this stage. In this positive magnetization state, the magnetic medium 40 possesses multiple different quantitative magnetization states, corresponding to multiple different quantitative magnetization fields, reflecting the coercive magnetic characteristics of the magnetic medium 40.

[0056] Specifically, in determining the coercive magnetic properties of a magnetic medium based on its magnetization state and detection signal, if the magnetic medium 40 changes from a positively magnetized state to a saturated magnetized state, the critical magnetization field of the magnetized magnetic medium 40 is determined to be a saturated coercive magnetization field. If the magnetic medium 40 is in a negatively magnetized state and the amplitude of the detection signal is zero, the critical magnetization field of the magnetized magnetic medium 40 is determined to be a remanent coercive magnetization field. If the magnetic medium 40 changes from a positively magnetized state to a saturated magnetized state, that is, the detection signal changes from an increasing amplitude to a constant amplitude, it indicates that under the quantitative magnetization of a changing magnetic field, the magnetic medium 40 is positively magnetized and changes towards saturation magnetization. The magnetization field that causes the magnetic medium 40 to change from a positively magnetized state to a saturated magnetized state is considered the saturated coercive magnetization field, representing one type of coercive magnetic property of the magnetic medium 40.

[0057] Similarly, if the magnetic medium 40 is in a reverse magnetization state and the amplitude of the detection signal is zero, that is, when the amplitude of the detection signal decreases to zero, the magnetization field of the magnetized magnetic medium 40 at this time is used as the remanent coercive magnetization field, representing another type of coercive magnetic characteristic of the magnetic medium 40.

[0058] Specifically, during the magnetization process of the magnetic medium 40 and the generation of a detection signal by the detection component 30 of the magnetic medium performance detection device, the magnetization component 20 of the detection device is controlled to generate a magnetization field with a monotonically changing magnetic field strength interval. Because the magnetization field is controlled to change at intervals, the magnetic medium 40 can be quantitatively magnetized multiple times. The monotonically changing magnetization field ensures accurate judgment of the magnetization state of the magnetic medium, thereby obtaining accurate data on the saturation coercivity magnetization field and the remanent coercivity magnetization field.

[0059] In the process of acquiring data of the saturated coercive magnetization field, during the magnetization of the magnetic medium 40 and the generation of a detection signal by the detection component 30 of the magnetic medium performance detection device, the positive interval of the magnetic field strength of the magnetization field increases. By controlling the increase of the positive interval of the magnetic field strength of the magnetization field, the magnetic medium 40 can obtain an increasing amplitude of the detection signal under the influence of its coercive magnetic properties, thereby placing the magnetic medium 40 in a positive magnetization state. Furthermore, as the magnetic field strength continuously increases, a saturated magnetization state can be reached, thus allowing the acquisition of data of the saturated coercive magnetization field.

[0060] Specifically, the method for detecting the performance of a magnetic medium also includes a first preprocessing step before the process of magnetizing the magnetic medium 40 and generating a detection signal through the detection component 30 of the magnetic medium performance detection device. The first preprocessing step includes: demagnetizing the magnetic medium 40; and after the first preprocessing step is completed, during the process of magnetizing the magnetic medium 40 and generating a detection signal through the detection component 30 of the magnetic medium performance detection device, the state of the magnetization component 20 is controlled to ensure that the magnetic field strength of the magnetization field increases in the positive direction. In other words, in order to obtain data on the saturated coercive magnetization field, the magnetic medium 40 needs to undergo a first preprocessing step to demagnetize it, so as to avoid the magnetic field of the magnetic medium 40 itself affecting the detection signal.

[0061] It should be noted that after the magnetic medium 40 is demagnetized, the detection signal obtained by the detection component 30 is zero, which proves that the magnetic medium 40 has been completely demagnetized.

[0062] During the acquisition of data on the remanent coercive magnetization field, while magnetizing the magnetic medium 40 and generating a detection signal through the detection component 30 of the magnetic medium performance detection device, the reverse interval of the magnetic field strength of the magnetization field increases. By controlling the increase of the reverse interval of the magnetic field strength of the magnetization field, the amplitude of the detection signal obtained by the magnetic medium 40 under the influence of the coercive magnetic properties decreases, thereby placing the magnetic medium 40 in a reverse magnetization state.

[0063] Specifically, the method for detecting the performance of magnetic media also includes a second preprocessing step before the process of magnetizing the magnetic media 40 and generating a detection signal through the detection component 30 of the magnetic media performance detection device. The second preprocessing step includes: saturating the magnetic media 40 with magnetization; and after the second preprocessing step is completed, during the process of magnetizing the magnetic media 40 and generating a detection signal through the detection component 30 of the magnetic media performance detection device, the state of the magnetization component 20 is controlled so that the magnetic field strength of the magnetization field satisfies the requirement of increasing reverse interval. That is, in order to obtain the data of the remanent coercive magnetization field, the magnetic media 40 needs to undergo the second preprocessing step to make the magnetic media 40 saturated with magnetization. When the magnetic media 40 is detected at this time, the amplitude of the obtained detection signal has a certain magnitude. Under multiple quantitative magnetizations of the magnetization field with increasing reverse interval, the amplitude of the detection signal decreases until the first detection signal with an amplitude of zero appears, indicating that the critical magnetization field at this time is the remanent coercive magnetization field.

[0064] It should be noted that the saturation magnetization of the magnetic medium 40 in the second preprocessing step can be a separate saturation magnetization process of the magnetic medium 40, or it can be that after the magnetic medium 40 is magnetized to a saturation magnetization state in one of the above optional embodiments, the magnetic field strength of the magnetization field is controlled to satisfy the reverse interval increase in order to obtain the remanent coercive magnetization field data.

[0065] In an optional embodiment, the method for detecting the performance of a magnetic medium includes at least the following steps: Step S11: controlling the magnetization field to be at an initial magnetic field strength and recording the result; Step S12: controlling the rotating cylinder 11 of the rotating assembly 10 of the magnetic medium performance detection device to rotate one revolution, so that the magnetic medium 40 passes through the magnetization range and the detection range successively, and recording the detection signal; Step S13: controlling the magnetic field strength of the magnetization field to change once, and recording the result; Step S14: repeating steps S12 and S13 until the amplitude of the detection signal remains unchanged or the amplitude of the detection signal decreases to zero. In the above steps, by controlling the rotation of the rotating cylinder 11, the magnetic medium 40 passes through the magnetization range and the detection range successively in each rotation cycle, that is, after undergoing a quantitative magnetization once, the detection assembly 30 detects the magnetic medium 40. After multiple rotations, the magnetic medium 40 is quantitatively magnetized multiple times and is in different magnetization states.

[0066] Since the magnetic medium performance detection device provided by the present invention can generate a magnetizing field for quantitative magnetization of the magnetic medium 40, the magnetic medium 40 can be magnetized to different states according to different coercive magnetic properties. The detection component 30 of the magnetic medium performance detection device can quantitatively detect the signal magnitude of the magnetic medium, thereby realizing the quantitative detection of the coercive magnetic properties of the magnetic medium. The magnetic medium performance detection method provided by the present invention does not require the magnetic medium 40 to be sampled for detection during the detection process. It is suitable for non-destructive detection of the performance of the magnetic medium 40 over a large area, and has great advantages over the current destructive sampling magnetic medium performance detection methods.

[0067] Example 1

[0068] like Figure 3 As shown, in order to obtain data on the saturation coercive magnetization field, after the magnetic medium 40 is demagnetized and magnetized, the magnetization component 20 sequentially generates magnetization fields H with increasing positive intervals. 11 H 12 H 13 ..., the signals collected sequentially by the detection component 30 are M 11 M 12 M 13 ..., the acquired signal is characterized by a sequential increase in amplitude. When H is generated... 1n When the magnetized field is applied, the detection signal M detected by the detection component 30 is... 1n Compared with the previous magnetization field H 1n-1 Magnetic medium signal M detected after magnetization 1n-1 If they are the same, then the magnetization field H 1n-1 A saturated coercive magnetization field with a size of 40 for the magnetic medium.

[0069] Example 2

[0070] like Figure 4 As shown, in order to obtain data on the remanent coercive magnetization field, after the magnetic medium 40 is saturated magnetized, the magnetization component 20 sequentially generates magnetization fields H with increasing reverse intervals. 21 H 22 H 23 ..., the signals collected sequentially by the detection component 30 are M 21 M 22 M 23 ..., the acquired signal is characterized by a sequential decrease in amplitude. When H is generated... 2n When the magnetization field is activated, the detection signal detected by the detection component 30 first shows a zero signal, that is, the amplitude of the detection signal is zero. Then the magnetization field H... 2n A remanent coercive magnetization field with a size of 40 for the magnetic medium.

[0071] Optionally, after obtaining the saturated coercive magnetization field of the magnetic medium 40 by means of Example 1, the magnetic medium 40 is saturated magnetized under the saturated coercive magnetization field.

[0072] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0073] 1. By placing the magnetic medium 40 on the rotating component 10 and rotating with the rotating component 10, the magnetic medium 40 can pass through the magnetization range multiple times and be subjected to multiple quantitative magnetizations by the magnetization component 20.

[0074] 2. Using the magnetic medium performance testing device of this application, the magnetic medium 40 can be placed directly on the rotating component 10 without damaging its integrity, thus realizing non-destructive testing of the magnetic medium performance.

[0075] 3. When the rotating component 10 rotates one revolution, it will be magnetized once by the magnetization component 20 and detected once by the detection component 30, ensuring the timeliness of the detection of the magnetic medium 40.

[0076] 4. By controlling the positive interval of the magnetic field strength of the magnetizing field to increase, the magnetic medium 40 can obtain an increasing amplitude of the detection signal under the influence of its coercive magnetic properties, thereby placing the magnetic medium 40 in a positive magnetization state. Furthermore, as the magnetic field strength continuously increases, a saturation magnetization state can be reached, thus obtaining data on the saturated coercive magnetization field.

[0077] 5. By controlling the magnetic field strength of the magnetizing field to increase the reverse interval, the magnetic medium 40 can obtain a decreasing amplitude of the detection signal under the influence of the coercive magnetic properties until the first detection signal with an amplitude of zero appears. The critical magnetizing field at this time is the remanent coercive magnetizing field.

[0078] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0079] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0080] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for detecting the properties of a magnetic medium, characterized in that, include: Rotating assembly (10), the rotating assembly (10) is used to drive the magnetic medium (40) to rotate; A magnetization component (20) is located outside the rotation circumference of the rotation component (10). The magnetization component (20) is used to generate multiple magnetization fields with different magnetic field strengths. The magnetic field strengths of the multiple magnetization fields are spaced apart and monotonically changed, so that when the magnetic medium (40) rotates to the magnetization range of the magnetization component (20), the magnetization component (20) quantitatively magnetizes the magnetic medium (40). The detection component (30) has no built-in magnetic field. The detection component (30) is located outside the rotation circumference of the rotation component (10) and is spaced apart from the magnetization component (20). When the magnetic medium (40) rotates to the detection range of the detection component (30), the detection component (30) quantitatively detects the performance of the magnetic medium (40) and generates a detection signal. In each rotation cycle of the rotating component (10), the magnetic medium (40) is magnetized by the magnetization component (20) and detected by the detection component (30) in turn, so as to complete one quantitative magnetization of the magnetization component (20) and one quantitative detection of the detection component (30). The magnetization range of the magnetization component (20) is radial, and the starting center of the radiation is at the point where the distance between the magnetization component (20) and the rotating component (10) is the shortest. The magnetization component (20) includes an electromagnet. During different rotation cycles of the rotation component (10), the magnetic field strength of the magnetization field generated by the electromagnet is different, so that the magnetic medium (40) has different magnetization states under the influence of coercive magnetic properties.

2. The device for detecting the properties of magnetic media according to claim 1, characterized in that, The rotating assembly (10) includes a rotating cylinder (11), and the magnetic medium (40) is disposed on the surface of the rotating cylinder (11).

3. The device for detecting the properties of magnetic media according to claim 2, characterized in that, The magnetic medium (40) is adhered to the surface of the rotating cylinder (11).

4. The device for detecting the properties of magnetic media according to claim 2, characterized in that, The rotating cylinder (11) has an adsorption area on its surface, and the adsorption area has multiple adsorption holes. Air is drawn out from inside the rotating cylinder (11) so that the magnetic medium (40) is adsorbed on the adsorption area.

5. The device for detecting the properties of magnetic media according to claim 2, characterized in that, The rotating cylinder (11) rotates at a constant speed.

6. The apparatus for detecting the properties of a magnetic medium according to any one of claims 1 to 5, characterized in that, The detection component (30) includes a coil-type induction magnetic head magnetic sensor; or The detection component (30) includes a TMR magnetoresistive element, which has no built-in magnet.

7. The apparatus for detecting the properties of magnetic media according to any one of claims 1 to 5, characterized in that, The magnetization field is less than or equal to 10000 Oe.

8. A method for detecting the properties of a magnetic medium, characterized in that, The device for detecting the properties of a magnetic medium according to any one of claims 1 to 7 comprises: The magnetic medium (40) is magnetized, and a detection signal is generated by the detection component (30) of the detection device for detecting the performance of the magnetic medium. The magnetization component (20) of the detection device is controlled to generate a magnetization field with an interval and monotonically changing magnetic field strength. The magnetization state of the magnetic medium (40) is determined by monitoring the change pattern of the detection signal; The coercive magnetic properties of the magnetic medium (40) are determined based on the magnetization state and the detection signal.

9. The method for detecting the properties of a magnetic medium according to claim 8, characterized in that, During the process of magnetizing the magnetic medium (40) and generating a detection signal through the detection component (30) of the magnetic medium performance detection device, If the amplitude of the detection signal increases, it is determined that the magnetic medium (40) is in a positive magnetization state. If the amplitude of the detection signal remains unchanged, it is determined that the magnetic medium (40) is in a saturated magnetization state; If the amplitude of the detection signal decreases, it is determined that the magnetic medium (40) is in a reverse magnetization state.

10. The method for detecting the properties of a magnetic medium according to claim 9, characterized in that, In the process of determining the coercive magnetic properties of the magnetic medium (40) based on the magnetization state and the detection signal, If the magnetic medium (40) changes from a positive magnetization state to a saturated magnetization state, then the critical magnetization field for magnetizing the magnetic medium (40) is determined to be a saturated coercive magnetization field. If the magnetic medium (40) changes from a saturated magnetization state to a reverse magnetization state, and the amplitude of the detection signal is zero when the magnetic medium (40) is in a reverse magnetization state, then the critical magnetization field for magnetizing the magnetic medium (40) is determined to be a remanent coercive magnetization field.

11. The method for detecting the properties of a magnetic medium according to claim 8, characterized in that, During the process of magnetizing the magnetic medium (40) and generating a detection signal through the detection component (30) of the detection device for detecting the properties of the magnetic medium, the magnetic field strength of the magnetizing field increases in the positive direction.

12. The method for detecting the properties of a magnetic medium according to claim 8, characterized in that, The method for detecting the properties of a magnetic medium further includes a first preprocessing step before the process of magnetizing the magnetic medium (40) and generating a detection signal through the detection component (30) of the magnetic medium properties detection device. The first preprocessing step includes: The magnetic medium (40) is demagnetized; After the first preprocessing step is completed, during the process of magnetizing the magnetic medium (40) and generating a detection signal through the detection component (30) of the magnetic medium performance detection device, the magnetic field strength of the magnetization field is increased in the positive direction by controlling the state of the magnetization component (20).

13. The method for detecting the properties of a magnetic medium according to claim 8, characterized in that, During the process of magnetizing the magnetic medium (40) and generating a detection signal through the detection component (30) of the detection device for detecting the properties of the magnetic medium, the magnetic field strength of the magnetizing field increases in opposite directions.

14. The method for detecting the properties of a magnetic medium according to claim 8, characterized in that, The method for detecting the properties of a magnetic medium further includes a second preprocessing step before the process of magnetizing the magnetic medium (40) and generating a detection signal through the detection component (30) of the magnetic medium properties detection device. The second preprocessing step includes: The magnetic medium (40) is subjected to saturation magnetization treatment; After the second preprocessing step is completed, during the process of magnetizing the magnetic medium (40) and generating a detection signal through the detection component (30) of the magnetic medium performance detection device, the magnetic field strength of the magnetization field is increased by controlling the state of the magnetization component (20) to satisfy the reverse interval increase.

15. The method for detecting the properties of a magnetic medium according to claim 8, characterized in that, The method for detecting the properties of the magnetic medium includes at least the following: Step S11: Control the magnetization field to be at the initial magnetic field strength and record it; Step S12: The rotating cylinder (11) of the rotating assembly (10) of the detection device for the magnetic medium properties rotates one revolution, so that the magnetic medium (40) passes through the magnetization range and the detection range in turn, and the detection signal is recorded. Step S13: Control the magnetic field strength of the magnetization field to change once, and record the change; Step S14: Repeat steps S12 and S13 until the amplitude of the detection signal remains unchanged or the amplitude of the detection signal decreases to zero.

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