JP2010157002A - Electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic device that uses a non-contact magnetic sensor to detect two or more different gaps between a first body and a second body, allowing the first and second bodies to be shifted to respective predetermined modes. <P>SOLUTION: A display housing 2 and an operation housing 3 are openably/closably interconnected by a hinge section. The display housing 2 incorporates a magnet 7, and the operation housing 3 incorporates a non-contact magnetic sensor 8 having a magneto-resistive effect element (GMR element). The magnetic sensor 8 generates a first detection signal by detecting the intensity of an external magnetic field in the middle of closing of the display housing 2 and the operation housing 3 with respect to each other. In a control section, the detection signal activates a consumption power reduction mode which is simpler than a sleep mode. When the display housing 2 and the operation housing 3 are closed together, the magnetic sensor 8 generates a second detection signal and the control section activates the sleep mode. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic device that uses a non-contact type magnetic sensor and can detect two or more different intervals between a first main body and a second main body, and each shift to a predetermined mode.

  For example, in a notebook personal computer in which a display housing and an operation housing are connected via a hinge portion, when the display housing and the operation housing are closed, a mechanical switch is pressed to enter a sleep mode. Controlled to migrate.

In the folding cellular phone, the backlight provided in the display casing is automatically turned on when the display casing and the operation casing are opened.
JP 2003-007168 A Japanese Patent No. 2944910

  For example, in the above-described notebook personal computer, when the sleep mode is entered, the device does not restart immediately even if the display housing and the operation housing are opened, and a predetermined access condition, for example, a password is set. It was necessary to enter.

  The sleep mode is used for a notebook personal computer or the like as a mechanism for stopping the device and consuming only the power for restarting and reducing the power consumption of the device.

  The sleep mode is effective when the notebook personal computer is not used for a long time, but when the notebook personal computer is shifted to the sleep mode every time the laptop is closed for a short time, the device is turned on each time. The operation to raise was required, and usability was bad.

In addition, conventionally, a mechanical switch is used to detect that the display housing and the operation housing are closed and shift to the sleep mode. For example, the intermediate state from the opened state to the closed state is detected. I wasn't trying to activate any mode other than sleep mode.
The same applies to folding mobile phones, and conventionally only open / close detection has been performed.

  Patent Documents 1 and 2 described above disclose a switch mechanism that can perform a plurality of switching operations according to a pressing distance (pressing force).

  However, since the switches described in Patent Documents 1 and 2 described above are contact type, for example, when the switch is mounted on a notebook computer or the like, long life could not be obtained due to wear caused by pressing. . Also, it is difficult to reduce the size of the switch structure. Further, since the switch is a contact type switch, it is impossible to detect the intermediate state from the opened state to the closed state between the display housing and the operation housing.

  The present invention is to solve the above-described conventional problems, and in particular, a non-contact magnetic sensor is used to detect two or more different intervals between the first main body and the second main body, An object of the present invention is to provide an electronic device capable of shifting to a mode.

The electronic device of the present invention has a first main body and a second main body, and the interval between the first main body and the second main body is variable.
A non-contact type magnetic sensor provided with a magnetic detection element capable of detecting an external magnetic field emitted from the magnet on one of the first main body and the second main body, and the other;
The magnetic sensor has at least the first distance of the external magnetic field when the first distance between the magnet and the magnetic detection element becomes a first distance with the first body and the second body open. And detecting the first detection signal when the second distance between the magnet and the magnetic detection element becomes a second distance smaller than the first distance. Detecting a magnetic field intensity based on the distance and generating a second detection signal,
Based on the first detection signal and the second detection signal, a control unit capable of shifting to a predetermined mode is provided.

  According to the present invention, in an electronic device in which the interval between the first main body and the second main body varies, it is possible to shift to a predetermined mode according to two or more different intervals. Therefore, for example, when switching between the first main body and the second main body of the notebook personal computer, it is possible to perform mode switching that is richer in variety than in the past. Further, by using a non-contact type magnetic sensor, a long life can be obtained, and miniaturization of the magnetic sensor can be promoted.

  In the present invention, the magnetic sensor includes the first main body and the second main body separately from the second detection signal used for detecting the open / close between the first main body and the second main body and the open / close detection. It is preferable to generate the first detection signal for detecting an intermediate state from an open state to a close state. For example, the open / close detection may be performed by another magnetic sensor or a mechanical switch as in the past, but the magnetic sensor of the present invention also serves as the open / close detection, thereby simplifying the sensor mechanism mounted on the electronic device. be able to.

For example, the electronic device of the present invention is a notebook personal computer including a display unit in the first main body and an operation unit in the second main body,
In use, when the distance between the first main body and the second main body is moved from the open state to the closing direction to reach the first distance, the consumption is simpler than the sleep mode based on the first detection signal. Transition to power reduction mode,
When the second distance is reached, it is preferable to shift to the sleep mode based on the second detection signal.

  In the present invention, the control unit controls the power consumption reduction mode to be released and return to the use state when the first body and the second body are reopened from the first distance. Is preferred.

  In the power consumption reduction mode, it is preferable that the display on the display unit is controlled to disappear. At this time, in the power consumption reduction mode, it is preferable that the backlight provided on the back side of the display unit is controlled to be turned off.

  “Use state” refers to a state in which various devices are activated after the power is turned on. As described above, the simple power consumption reduction mode can be activated before entering the sleep mode between the first main body and the second main body until the first main body and the second main body are closed. Since the power consumption reduction mode is canceled and the use state can be restored by opening between the main body and the second main body, for example, when the notebook type personal computer is not used for a short time, it is consumed without going into the sleep mode. Electric power can be reduced, and usability can be improved.

The electronic device of the present invention is a foldable mobile phone including a display unit in the first main body and an operation unit in the second main body,
In the call state, when the first main body and the second main body are moved from the opened state to the closing direction to reach the first distance, the call shift mode is set based on the first detection signal,
When the second distance is reached by moving the first main body and the second main body from the first distance in the closing direction, the call shift mode is entered based on the second detection signal. It is preferable.

  Further, at this time, the control unit is controlled so that when the first main body and the second main body are opened again from the first distance, the call hold mode is canceled and the call state can be restored. preferable.

  Conventionally, in order to put a call on hold, an operation such as pressing a predetermined button of the operation unit during the call is required. However, in the present invention, the first main body and the second main body are closed from the opened state. It is possible to shift to the call hold mode simply by moving to the middle, and to return to the call state again simply by opening the first main body and the second main body from that state.

  In the present invention, the magnetic sensor includes a first magnetoresistive element and a second magnetoresistive element that use a magnetoresistive effect having different magnetic sensitivities with respect to the magnetic field strength of the external magnetic field from the same direction, The first detection signal is generated based on a change in the electrical resistance value of the first magnetoresistance effect element, and the second detection signal is generated based on a change in the electrical resistance value of the second magnetoresistance effect element. It is preferable. Thereby, the magnetic field intensity from which the external magnetic field from the same direction differs can be detected appropriately.

  Further, in the present invention, it is preferable that each detection signal is generated by a common threshold value because the circuit configuration of the magnetic sensor can be simplified and the size of the magnetic sensor can be reduced.

  In the present invention, in an electronic device in which the interval between the first main body and the second main body varies, it is possible to shift to a predetermined mode according to two or more different intervals.

  FIG. 1 is a perspective view of a notebook personal computer (electronic device). FIG. 2 is a side view of the notebook personal computer showing a state of the notebook personal computer shown in FIG. 3 is a side view of a notebook personal computer showing a state in which the notebook personal computer is closed, FIG. 4 is a plan view of a foldable mobile phone (electronic device), and FIG. 5 is an open view of the foldable mobile phone of FIG. FIG. 6 is a side view of the foldable mobile phone showing a state in which the foldable mobile phone is closed, and FIG. FIG. 8 is a plan view of the magnetic sensor of the present embodiment, and FIG. 9 is a sectional view of a magnetoresistive effect element (GMR element) built in the magnetic sensor. FIG. 10 is a partial block diagram of a notebook personal computer according to the present embodiment, FIG. 11 is a partial block diagram of a folding cellular phone according to the present embodiment, and FIG. 12 is a diagram showing a first magnetoresistive element and a second magnetic resistance. FIG. 13 is a graph showing the relationship between the external magnetic field and the voltage value after shaping based on the electrical resistance change of the first magnetoresistance effect element, and FIG. 14 is an external magnetic field. It is a graph which shows the relationship between the voltage value after shaping based on the electrical resistance change of a 2nd magnetoresistive effect element.

  In a notebook personal computer 1 shown in FIG. 1, a display housing 2 and an operation housing 3 are connected via a hinge part so as to be freely opened and closed. FIG. 1 shows a use state in which the display housing 2 and the operation housing 3 are opened.

  As shown in FIG. 1, a display unit 4 such as a liquid crystal is provided on a surface 2 a of the display housing 2 facing the operation housing 3. An operation unit 19 such as a keyboard 5 or a touch pad 6 is provided on a surface 3 a of the operation housing 3 facing the display housing 2.

  As shown in FIG. 1, a magnet 7 is provided inside the display housing 2, and a non-contact type magnetic sensor 8 is provided inside the operation housing 3. The magnet 7 and the magnetic sensor 8 are arranged at positions that face each other in the height direction when the display housing 2 and the operation housing 3 are closed, or are slightly shifted from the facing positions. (See FIG. 3).

  In the use state shown in FIG. 1, the power is turned on and various devices are activated. The display unit 4 displays various icons on the desktop, characters typed with the keyboard 5, and the like.

When the display housing 2 is rotated by the hinge portion in the use state in which the device is activated as described above, the display housing 2 and the operation housing 3 are brought close to the state of FIG. A distance between the magnet 7 and a magnetic detection element for detecting an external magnetic field included in the magnetic sensor 8 is a first distance T1, and the magnetic sensor 8 is a first external magnetic field emitted from the magnet 7. to the generating the first detection signal by detecting the magnetic field strength H _a output. The first distance T1 and the second distance T2 described later are, for example, the film thickness center of the magnet 7 to the film thickness center of the magnetic detection element (in the case of a magnetoresistive effect element described later, the film thickness of the free magnetic layer). Defined as the straight line distance to the center).

  As shown in FIG. 10, when the first detection signal is input from the magnetic sensor 8 to the control unit 9 built in the notebook personal computer 1, the control unit 9 Based on the detection signal, for example, inside the display housing 2, the backlight (not shown) provided on the back side of the display unit 4 is turned off, and the power consumption for turning off the display of the display unit 4 is reduced. Transition to reduction mode.

  This small power consumption reduction mode is a simple power consumption mode compared to the sleep mode because it only turns off the backlight. Here, “simple” refers to a state in which the debiasing that is being activated is smaller than that in the sleep mode. In the low power consumption reduction mode, the input device such as the keyboard 5 and the mouse, and various devices such as the CPU and the storage device remain activated, and, for example, just turn off the backlight as described above. Therefore, in the low power consumption reduction mode, the effect of reducing the power consumption is small compared to the sleep mode, but the control unit 9 returns from the state of FIG. 2 to the state of FIG. When the window is opened, the low power consumption reduction mode is canceled, the backlight is turned on, and the display unit 4 is controlled so that it can return to the use state before the notebook personal computer 1 is closed. Therefore, the present invention can be effectively applied to a case where the notebook personal computer 1 is not used for a short time and the sleep mode is not intentionally set.

  On the other hand, as shown in FIG. 3, when the display housing 2 and the operation housing 3 are closed, the distance between the magnet 7 and the magnetic detection element provided in the magnetic sensor 8 is greater than the first distance T1 shown in FIG. Becomes a short second distance T2.

The external magnetic field received by the magnetic sensor 8 in the closed state as shown in FIG. 3 and the external magnetic field received by the magnetic sensor 8 during the intermediate state until the closing shown in FIG. 2 are in the same direction, but in the state of FIG. Compared with the state of 2, the magnetic field intensity of the external magnetic field H emitted from the magnet 7 to the magnetic sensor 8 is increased. At this time, the magnetic sensor 8 detects a second magnetic field strength H _B (stronger than the first magnetic field strength H _{A in} FIG. 2) of the external magnetic field emitted from the magnet 7 and generates a second detection signal. And output.

  Then, when the second detection signal is input to the control unit 9 shown in FIG. 10, the control unit 9 stops various devices based on the second detection signal as long as there is no access for a certain period of time. Transition to sleep mode, which consumes only power for restarting. Activation of the sleep mode is effective when the notebook personal computer 1 is not used for a long time.

  Once in the sleep mode, even if the display housing 2 and the operation housing 3 are opened from the state of FIG. 3 to the state of FIG. 2 and further to the state of FIG. The sleep mode can be canceled by a predetermined access such as pressing a predetermined button on the keyboard 5.

  As described above, in the magnetic sensor 8 provided in the notebook personal computer 1 of the present embodiment, the magnet 7 and the magnetic sensor 8 are provided in the process of closing the space between the display housing 2 and the operation housing 3. The control unit 9 generates a first detection signal and a second detection signal according to the distance between the magnetic detection elements, and the control unit 9 determines a predetermined value based on the first detection signal and the second detection signal, respectively. It is controlled so that it can shift to the mode.

  Conventionally, the sleep mode is controlled to be activated when the display housing 2 and the operation housing 3 of the notebook personal computer 1 are closed. However, the consumption is simpler than that in the sleep mode in the middle state until the close. There was no control to activate the power reduction mode. In this embodiment, before entering the sleep mode, it is controlled so that a simple power consumption reduction mode can be activated in the middle state until closing, and thus the user of the notebook personal computer 1 With a very simple operation of opening and closing the notebook personal computer 1, it is possible to select a simple power consumption reduction mode or a sleep mode, and usability can be improved as compared with the conventional case.

  In addition, when the display housing 2 and the operation housing 3 are opened from the state of FIG. 2 to the state of FIG. 1, the power consumption reduction mode may be canceled by a simple operation such as moving a mouse. However, by simply opening the display housing 2 and the operation housing 3 again from the state of FIG. 2 to the state of FIG. 1, for example, the backlight activated in FIG. If the low power consumption reduction mode to be turned off is canceled so that it can be returned to the use state, the notebook personal computer 1 of the present embodiment can be used by the user when the notebook personal computer 1 is not used for a short time. It will be very easy to use.

Further, for example, since the opening / closing detection between the display housing 2 and the operation housing 3 can be performed by detecting the second magnetic field strength H _{B in} FIG. 3, a separate magnetic sensor or machine is used for the opening / closing detection. There is no need to use a typical switch or the like, and the sensor mechanism mounted on the notebook personal computer 1 can be simplified.

  In the present embodiment, since a non-contact type magnetic sensor is used, a long life can be obtained, and further downsizing of the magnetic sensor can be promoted.

  The non-contact type magnetic sensor 8 and the magnet 7 of this embodiment may be incorporated in the foldable mobile phone 10 shown in FIG.

  In the foldable mobile phone 10, a display housing 11 and an operation housing 12 are connected via a hinge portion 13 so as to be freely opened and closed. A display unit 20 and a speaker 14 are provided on the facing surface 11 a of the display casing 11 that faces the operation casing 12 when the foldable mobile phone 10 is closed. Various buttons 15 and a microphone 16 are provided on the facing surface 12a of the operation casing 12 that faces the display casing 11 when the foldable mobile phone 10 is closed.

  As shown in FIG. 4, a magnet 7 is provided inside the display housing 11, and a non-contact type magnetic sensor 8 is provided inside the operation housing 12. The magnet 7 and the magnetic sensor 8 are disposed at positions that face each other in the height direction when the display housing 11 and the operation housing 12 are closed, or are slightly shifted from the facing positions. (See FIG. 6).

  Assume that the communication mode is set in a state where the display housing 2 and the operation housing 3 shown in FIG. 4 are opened.

Thus, when the display casing 11 is rotated by the hinge 13 in the state of the call mode and the display casing 11 and the operation casing 12 are brought close to the state shown in FIG. The distance between the magnetic detection elements for detecting the external magnetic field included in the magnetic sensor 8 is a first distance T1, and the magnetic sensor 8 is a first magnetic field of the external magnetic field emitted from the magnet 7. The intensity _HA is detected and a first detection signal is generated and output.

  As shown in FIG. 11, when the first detection signal is input from the magnetic sensor 8 to the control unit 17 built in the foldable mobile phone 10, the control unit 17 Based on the detection signal, the hold sound is sent from the holding sound unit 18 to the speaker 14 and the call holding mode is entered in which the use of the microphone 16 is interrupted.

  When the display housing 11 and the operation housing 12 are opened again from the state of FIG. 5 to the state of FIG. 4, there is no input to the control unit 17 of the first detection signal, and the mode is again switched to the call mode. To do.

  On the other hand, as shown in FIG. 6, when the space between the display housing 11 and the operation housing 12 is closed, the distance between the magnetic detection elements provided in the magnet 7 and the magnetic sensor 8 is larger than the first distance T1 shown in FIG. The second distance T2 is short.

The external magnetic field received by the magnetic sensor 8 in the closed state as shown in FIG. 6 and the external magnetic field received by the magnetic sensor 8 in the middle state until the closing shown in FIG. 5 are in the same direction, but in the state of FIG. Compared with the state 5, the magnetic field intensity of the external magnetic field H emitted from the magnet 7 to the magnetic sensor 8 is increased. At this time, the magnetic sensor 8 detects a second magnetic field strength H _B (stronger than the first magnetic field strength H _{A in} FIG. 5) of the external magnetic field emitted from the magnet 7 and generates a second detection signal. And output.

  Then, when the second detection signal is input to the control unit 17 shown in FIG. 11, the control unit 17 invalidates the use of the speaker 14 and the microphone 16 based on the second detection signal. The mode is switched to the mode for disconnecting the telephone call, that is, the mode for disconnecting the telephone.

  As described above, the foldable mobile phone 10 according to the present embodiment includes a call holding mode according to the distance between the magnet 7 and the magnetic sensor 8 in the process of closing the display housing 11 and the operation housing 12. Alternatively, a control unit 17 that can shift to the call disconnect mode is provided.

  Thus, in this embodiment, since it is possible to change the distance between the display housing 11 and the operation housing 12 when closing these two modes, the user who is talking on the folding mobile phone 10 can It is possible to select, for example, whether to hold the call or to disconnect the call by a very simple operation, and the usability can be improved as compared with the conventional case.

  Further, when the display housing 11 and the operation housing 12 are opened from the state of FIG. 5 to the state of FIG. 4, for example, a predetermined button may be pressed to cancel the call hold mode. If the user returns to the call mode by simply opening the display housing 11 and the operation housing 12 from the state shown in FIG. 4 to the state shown in FIG. 4, problems such as pressing the wrong button to hang up the phone are unlikely to occur. Convenience is good.

In addition, since the opening / closing detection between the display housing 11 and the operation housing 12 can be performed by detecting the second magnetic field strength H _{B in} FIG. 6, a separate magnetic sensor or mechanical device is used for the opening / closing detection. There is no need to use a switch or the like, and the sensor mechanism mounted on the foldable mobile phone 10 can be simplified.

  In the present embodiment, since a non-contact type magnetic sensor is used, a long life can be obtained, and further downsizing of the magnetic sensor can be promoted.

  A specific configuration of the magnetic sensor 8 of the present embodiment will be described. As shown in FIG. 7, the magnetic sensor 8 of this embodiment includes a resistance element portion 21 and an integrated circuit (IC) 22.

  The resistance element section 21 includes a first series circuit 26 in which a first magnetoresistance effect element 23 and a first fixed resistance element 24 are connected in series via a first output extraction section 25, and a second fixed resistance element 27 and the second magnetoresistive effect element 28 are provided in a second series circuit 30 in which the second output extraction unit 29 is connected in series.

  As shown in FIG. 7, the integrated circuit 22 is provided with a third series circuit 34 in which a third fixed resistance element 31 and a fourth fixed resistance element 32 are connected in series via a third output extraction unit 33.

  The third series circuit 34 forms a bridge circuit with the first series circuit 26 and the second series circuit 30 as a common circuit. Hereinafter, a bridge circuit formed by connecting the first series circuit 26 and the third series circuit 34 in parallel is referred to as a first bridge circuit BC1, and the second series circuit 30 and the third series circuit 34 are connected in parallel. This bridge circuit is referred to as a second bridge circuit BC2.

  As shown in FIG. 7, in the first bridge circuit BC1, the first magnetoresistive effect element 23 and the fourth fixed resistance element 32 are connected in parallel, and the first fixed resistance element 24 and the third fixed resistance are connected. The resistance element 31 is connected in parallel. In the second bridge circuit BC2, the second fixed resistance element 27 and the third fixed resistance element 31 are connected in parallel, and the second magnetoresistance effect element 28 and the fourth fixed resistance element 32 are connected in parallel. It is connected.

  As shown in FIG. 7, an input terminal (power source) 39, a ground terminal 42, and two external output terminals 40 and 41 are provided in the main magnetic pole layer register circuit 22. The input terminal 39, the ground terminal 42, and the external output terminals 40 and 41 are electrically connected to terminal portions on the device side (not shown) by wire bonding, die bonding or the like.

  A signal line 50 connected to the input terminal 39 and a signal line 51 connected to the ground terminal 42 are provided at both ends of the first series circuit 26, the second series circuit 30, and the third series circuit 34. Connected to each of the electrodes.

  As shown in FIG. 7, a single differential amplifier 35 is provided in the integrated circuit 22, and the third series circuit 34 of the third series circuit 34 is connected to either the + input section or the −input section of the differential amplifier 35. An output extraction unit 33 is connected. The connection between the third output extraction unit 33 and the differential amplifier 35 is described below. The first output extraction unit 25 of the first series circuit 26 and the second output extraction unit 29 of the second series circuit 30 will be described below. Unlike the connection state between the differential amplifier 35 and the differential amplifier 35, they are fixed (not connected).

  The first output extraction section 25 of the first series circuit 26 and the second output extraction section 29 of the second series circuit 30 are connected to the input section of the first switch circuit 36, respectively. The output section of the first switch circuit 36 is The differential amplifier 35 is connected to either the − input part or the + input part (the input part on the side where the third output extraction part 33 is not connected).

  As shown in FIG. 7, the output section of the differential amplifier 35 is connected to a Schmitt trigger type comparator 38, the output section of the comparator 38 is further connected to the input section of a second switch circuit 43, and the second The output side of the switch circuit 43 is connected to the first external output terminal 40 and the second external output terminal 41 via the two latch circuits 46 and 47 and the FET circuits 54 and 55, respectively.

  Further, as shown in FIG. 7, a third switch circuit 48 is provided in the integrated circuit 22. The output part of the third switch circuit 48 is connected to a signal line 51 connected to the ground terminal 42, and the input part of the third switch circuit 48 is connected to the first series circuit 26 and the second series circuit 30. One end is connected.

  Further, as shown in FIG. 1, an interval switch circuit 52 and a clock circuit 53 are provided in the integrated circuit 22. When the switch of the interval switch circuit 52 is turned off, the power supply to the integrated circuit 22 is stopped. The on / off of the switch of the interval switch circuit 52 is interlocked with the clock signal from the clock circuit 53, and the interval switch circuit 52 has a power saving function for intermittently energizing.

  The clock signal from the clock circuit 53 is also output to the first switch circuit 36, the second switch circuit 43, and the third switch circuit 48. When receiving the clock signal, the first switch circuit 36, the second switch circuit 43, and the third switch circuit 48 are controlled so as to divide the clock signal and perform the switch operation with a very short cycle. For example, when one pulse of the clock signal is several tens of milliseconds, the switching operation is performed every several tens of micrometers.

  The magnetic sensor 8 is packaged as shown in FIG. 8, and the input terminal 39, the ground terminal 42, and the two external output terminals 40 and 41 are exposed on the outer periphery thereof.

  Both the first magnetoresistive element 23 and the second magnetoresistive element 28 are GMR elements that exhibit a giant magnetoresistive effect (GMR effect) based on a change in magnetic field strength of an external magnetic field in the (+ H) direction.

  Here, the external magnetic field in the (+ H) direction indicates a certain direction, and in this embodiment, the direction is in the X1 direction shown in the drawing (see FIG. 9).

  The layer structure and RH curve of the first magnetoresistive element 23 and the second magnetoresistive element 28 will be described in detail below.

  As shown in FIG. 9, the first magnetoresistive effect element 23 and the second magnetoresistive effect element 28 are both on the substrate 70 from below, the underlayer 60, the seed layer 61, the antiferromagnetic layer 62, and the fixed magnetic layer. 63, nonmagnetic intermediate layers 64 and 67 (the nonmagnetic intermediate layer of the first magnetoresistive effect element 23 is indicated by reference numeral 64, and the nonmagnetic intermediate layer of the second magnetoresistive effect element 28 is indicated by reference numeral 67), the free magnetic layer 65, And the protective layer 66 in this order. The underlayer 60 is made of, for example, a nonmagnetic material of one or more elements selected from Ta, Hf, Nb, Zr, Ti, Mo, and W. The seed layer 61 is made of NiFeCr or Cr. The antiferromagnetic layer 62 includes an anti-ferromagnetic material containing an element α (where α is one or more of Pt, Pd, Ir, Rh, Ru, and Os) and Mn. Or, element α and element α ′ (where element α ′ is Ne, Ar, Kr, Xe, Be, B, C, N, Mg, Al, Si, P, Ti, V, Cr, Fe, Co, Ni) , Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, Cd, Sn, Hf, Ta, W, Re, Au, Pb, and rare earth elements are one or more elements) and It is formed of an antiferromagnetic material containing Mn. For example, the antiferromagnetic layer 62 is made of IrMn or PtMn. The pinned magnetic layer 63 and the free magnetic layer 65 are made of a magnetic material such as a CoFe alloy, a NiFe alloy, or a CoFeNi alloy. The nonmagnetic intermediate layers 64 and 67 are made of Cu or the like. The protective layer 66 is made of Ta or the like. The pinned magnetic layer 63 and the free magnetic layer 65 have a laminated ferrimagnetic structure (magnetic layer / nonmagnetic layer / magnetic layer laminated structure in which the magnetization directions of two magnetic layers sandwiching the nonmagnetic layer are antiparallel) It may be. The pinned magnetic layer 63 and the free magnetic layer 65 may have a laminated structure of a plurality of magnetic layers made of different materials.

  In the first magnetoresistive element 23 and the second magnetoresistive element 28, the antiferromagnetic layer 62 and the pinned magnetic layer 63 are formed in contact with each other. An exchange coupling magnetic field (Hex) is generated at the interface between the layer 62 and the pinned magnetic layer 63, and the magnetization direction of the pinned magnetic layer 63 is fixed in one direction. In FIG. 9, the magnetization direction 63a of the pinned magnetic layer 63 is indicated by the arrow direction. In the first magnetoresistive effect element 23 and the second magnetoresistive effect element 28, the magnetization direction 63a of the fixed magnetic layer 63 is the X2 direction shown in the drawing.

  Further, the magnetization direction 65a of the free magnetic layer 65 in the absence of a magnetic field (when no external magnetic field is applied) is the X2 direction in the drawing for both the first magnetoresistance effect element 23 and the second magnetoresistance effect element 28. . Therefore, in the non-magnetic state, the magnetization direction 63a of the pinned magnetic layer 63 and the magnetization direction 65a of the free magnetic layer 65 are in a parallel state.

  As shown in FIG. 9, the film thickness of the nonmagnetic intermediate layers 64 and 67 is different between the first magnetoresistive element 23 and the second magnetoresistive element 28. The nonmagnetic intermediate layers 64 and 67 are made of Cu, for example, as described above, but the magnitude of the interlayer coupling magnetic field Hin acting between the pinned magnetic layer 63 and the free magnetic layer 65 by changing the Cu thickness. Changes.

  The first interlayer coupling magnetic field Hin1 acting on the first magnetoresistance effect element 23 and the second interlayer coupling magnetic field Hin2 acting on the second magnetoresistance effect element 28 have the same sign, and the first interlayer coupling magnetic field Hin1 The film thicknesses of the nonmagnetic intermediate layers 64 and 67 are adjusted so that the absolute value of is smaller than the absolute value of the second interlayer coupling magnetic field Hin2.

  FIG. 12 shows RH curves of the first magnetoresistance effect element 23 and the second magnetoresistance effect element 28. In the graph, the vertical axis represents the resistance value R, but the resistance change rate (%) may also be used. As shown in FIG. 12, when the external magnetic field is gradually increased from the zero magnetic field state (zero) in the (+ H) direction, the magnetization direction 65a of the free magnetic layer 65 of the first magnetoresistance effect element 23 and the fixed magnetic layer Since the parallel state with the magnetization direction 63a of 63 collapses and approaches an antiparallel state, the resistance value R of the first magnetoresistive effect element 23 gradually increases along the curve HC1, and eventually reaches the maximum resistance value. When the external magnetic field in the (+ H) direction is gradually reduced toward zero from there, the resistance value R of the first magnetoresistive element 23 gradually decreases along the curve HC2, and eventually reaches the minimum resistance. Reach value.

  Thus, the loop portion L1 surrounded by the curves HC1 and HC2 is formed in the RH curve of the first magnetoresistance effect element 23 with respect to the change in magnetic field strength of the external magnetic field in the (+ H) direction. . The intermediate value of the maximum resistance value and the minimum resistance value of the first magnetoresistive element 23, and the center value of the spread width of the loop portion L1 is the “midpoint” of the loop portion L1. The magnitude of the first interlayer coupling magnetic field Hin1 is determined by the strength of the magnetic field at the midpoint of the loop portion L1. As shown in FIG. 12, the first interlayer coupling magnetic field Hin1 of the first magnetoresistance effect element 23 is shifted in the direction of the external magnetic field in the (+ H) direction.

  As shown in FIG. 12, the electrical resistance value of the second magnetoresistance effect element 28 does not change at the magnetic field strength of the external magnetic field at which the electrical resistance value of the first magnetoresistance effect element 23 changes. That is, the magnetization direction 65a of the free magnetic layer 65 of the second magnetoresistive element 28 and the magnetization direction 63a of the pinned magnetic layer 63 maintain the parallel state shown in FIG.

  When the magnetic field strength of the external magnetic field from the (+ H) direction is further increased, the magnetization direction 65a of the free magnetic layer 65 of the second magnetoresistance effect element 28 gradually moves from the X2 direction to the X1 direction. Since the parallel state of the magnetization direction 65a of the free magnetic layer 65 and the magnetization direction 63a of the pinned magnetic layer 63 collapses and approaches an antiparallel state, the resistance value R of the second magnetoresistance effect element 28 is on the curve HC3. The maximum resistance value is reached after a while. When the magnetic field strength of the external magnetic field in the (+ H) direction is gradually reduced from there, the resistance value R of the second magnetoresistance effect element 28 gradually decreases along the curve HC4, and eventually the minimum resistance value. To reach.

  Thus, the loop portion L2 surrounded by the curves HC3 and HC4 is formed in the RH curve of the second magnetoresistive element 28 with respect to the change in the magnetic field strength of the external magnetic field in the (+ H) direction. . The intermediate value of the maximum resistance value and the minimum resistance value of the second magnetoresistive element 28, and the center value of the spread width of the loop portion L2 is the “midpoint” of the loop portion L1. The magnitude of the second interlayer coupling magnetic field Hin2 is determined by the strength of the magnetic field at the midpoint of the loop portion L2. As shown in FIG. 12, the second interlayer coupling magnetic field Hin2 of the second magnetoresistive effect element 28 is shifted to the external magnetic field direction in the (+ H) direction.

  If the magnetic field strength of the external magnetic field in the (+ H) direction is a positive value and the magnetic field strength of the external magnetic field in the (−H) direction opposite to the (+ H) direction is a negative value, the first magnetoresistance effect element 23 Both the first interlayer coupling magnetic field Hin1 and the second interlayer coupling magnetic field Hin2 of the second magnetoresistance effect element 28 are positive values. The first interlayer coupling magnetic field Hin1 of the first magnetoresistance effect element 23 and the second interlayer coupling magnetic field Hin2 of the second magnetoresistance effect element 28 may both be negative values.

  In any case, in the present embodiment, the first interlayer coupling magnetic field Hin1 and the second interlayer coupling magnetic field Hin2 have the same sign, and the absolute value of the first interlayer coupling magnetic field Hin1 and the absolute value of the second interlayer coupling magnetic field Hin2 Are adjusted to different sizes. Accordingly, the magnetic sensitivities of the first magnetoresistive effect element 23 and the second magnetoresistive effect element 28 with respect to the magnetic field strength of the external magnetic field from the same direction are different.

  In the present embodiment, both the first magnetoresistive element 23 and the second magnetoresistive element 28 change the electric resistance value with respect to the change in the magnetic field strength of the external magnetic field from the (+ H) direction, but the second magnetism. The resistance effect element 28 changes its electrical resistance value with a stronger magnetic field strength than the first magnetoresistance effect element 23.

  As described above, the reason why the first and second magnetoresistive elements 23 and 28 have different magnetic sensitivities with respect to the magnetic field intensity of the external magnetic field from the same direction is shown in FIGS. As described with reference to FIG. 6, the external magnetic field applied from the magnet 7 to the magnetic sensor 8 according to the opening / closing distance between the display housing and the operation housing is different in magnetic field strength but in the same direction.

  On the other hand, the first fixed resistance element 24, the second fixed resistance element 27, the third fixed resistance element 31, and the fourth fixed resistance element 32 do not change the electric resistance value with respect to the external magnetic field.

  For example, the first fixed resistance element 24, the second fixed resistance element 27, the third fixed resistance element 31, and the fourth fixed resistance element 32 are made of the same material as the first magnetoresistance effect element 23 and the second magnetoresistance effect element 28. Unlike the first magnetoresistive element 23 and the second magnetoresistive element 28, the free magnetic layer 65 and the nonmagnetic intermediate layer 64 are reversely stacked. That is, the first fixed resistance element 24, the second fixed resistance element 27, the third fixed resistance element 31, and the fourth fixed resistance element 32 are the base layer 60, the seed layer 61, the antiferromagnetic layer 62, and the fixed magnetic layer from the bottom. 63, a free magnetic layer 65, a nonmagnetic intermediate layer 64, and a protective layer 66 are laminated in this order. Since the free magnetic layer 65 is formed in contact with the pinned magnetic layer 63, unlike the first magnetoresistive effect element 23 and the second magnetoresistive effect element 28, the magnetization does not fluctuate with respect to an external magnetic field and is no longer free. It does not function as the magnetic layer 65 (like the pinned magnetic layer 63, it is a magnetic layer whose magnetization direction is fixed).

  Thus, the first fixed resistance element 24, the second fixed resistance element 27, the third fixed resistance element 31, and the fourth fixed resistance element 32 are connected to the first magnetoresistive effect element 23 and the second magnetoresistive effect element 28. By forming with the same material configuration, the temperature coefficient (TCR) of the first magnetoresistive effect element 23 and the second magnetoresistive effect element 28 and the temperature coefficient of each fixed resistance element 24, 27, 31, 32 are varied. Can be suppressed.

Next, the principle of detecting an external magnetic field will be described.
FIG. 7 shows a circuit state in which the first bridge circuit BC1 and the first external output terminal 40 are connected.

  When the external magnetic field in the (+ H) direction acting on the magnetic sensor 8 of this embodiment gradually increases from zero, first, the electrical resistance value of the first magnetoresistive effect element 23 fluctuates, and the first series circuit 26 of the first series circuit 26 changes. The midpoint potential at the one-output extraction unit 25 varies.

  In the circuit state shown in FIG. 1, the midpoint potential of the third output extraction unit 33 of the third series circuit 34 is set as a reference potential, and the first series circuit 26 and the third series circuit 34 are configured. A differential potential between the first output extraction unit 25 and the third output extraction unit 33 of the 1-bridge circuit BC1 is generated by the differential amplifier 35 and output to the comparator 38. In the comparator 38, the differential potential is shaped into a digital waveform by a Schmitt trigger input.

  FIG. 13 shows the relationship between the magnetic field strength of the external magnetic field H and the signal (voltage value) output from the first external output terminal 40. When the external magnetic field H becomes + H1 from the non-magnetic field state, the output signal changes from High to Low. On the other hand, when the external magnetic field H becomes + H2 or less, the output signal changes from Low to High.

  Next, it is considered that the second bridge circuit BC2 and the second external output terminal 41 are connected by the switching operation of the first switch circuit 36, the second switch circuit 43, and the third switch circuit 48 shown in FIG. .

  The external magnetic field in the (+ H) direction acting on the magnetic sensor 8 of the present embodiment gradually increases from zero, and the external magnetic field increases beyond the external magnetic field strength at which the electric resistance value of the first magnetoresistance effect element 23 fluctuates. As a result, the electric resistance value of the second magnetoresistive effect element 28 is fluctuated, and the midpoint potential of the second output extraction unit 29 of the second series circuit 30 is fluctuated.

  At this time, the midpoint potential of the third output extraction unit 33 of the third series circuit 34 is set as a reference potential, and the second bridge circuit BC2 configured by the second series circuit 30 and the third series circuit 34 is used. A differential potential between the output extraction unit 29 and the third output extraction unit 33 is generated by the differential amplifier 35 and output to the comparator 38. In the comparator 38, the differential potential is shaped into a digital waveform by a Schmitt trigger input.

  FIG. 14 shows the relationship between the magnetic field strength of the external magnetic field H and the signal (voltage value) output from the second external output terminal 41. When the external magnetic field H becomes + H3 from the non-magnetic field state, the output signal changes from High to Low. On the other hand, when the external magnetic field H becomes + H4 or less, the output signal changes from Low to High.

  In this embodiment, one differential amplifier 35 and one comparator 38 are provided as shown in FIG. 7, and the differential potential is shaped into a digital waveform by a Schmitt trigger input as shown in FIGS. The threshold level (threshold potential) is shared with the differential potential obtained from the first bridge circuit BC1 and the differential potential obtained from the second bridge circuit BC2. Therefore, the circuit configuration can be simplified.

  As described above, when the magnetic sensor 8 described with reference to FIGS. 7 to 9 and FIGS. 12 to 14 is incorporated in the notebook personal computer 1 shown in FIG. 1, the magnetic sensor 8 in the state shown in FIG. When the first magnetic field strength of the external magnetic field H acting on the first magnetoresistance effect element 23 is + H1, as shown in FIG. 13, the signal output from the first external output terminal 40 changes from High to Low, A Low signal (first detection signal) is transmitted into the control unit 9 shown in FIG. When receiving a Low signal from the first external output terminal 40, the control unit 9 is controlled to turn off the backlight provided in the display housing 2, and the display unit 4 is turned off by turning off the backlight. Disappears.

  When the display housing 2 and the operation housing 3 are opened from the state of FIG. 2 and the magnetic field strength of the external magnetic field H acting on the first magnetoresistive effect element 23 becomes + H2, it is output from the first external output terminal 40. The signal to be changed from Low to High, and the High signal is transmitted to the control unit 9 shown in FIG. When receiving a High signal from the first external output terminal 40, the control unit 9 is controlled to turn on the backlight provided inside the display housing 2, thereby returning to the use state.

  Further, as shown in FIG. 3, when the space between the display housing 2 and the operation housing 3 of the notebook personal computer 1 is closed, the second magnetic field strength of the external magnetic field H acting on the second magnetoresistive element 28 is + H3. As shown in FIG. 14, the signal output from the second external output terminal 41 changes from High to Low, and the Low signal (second detection signal) is transmitted into the control unit 9 shown in FIG. The The control unit 9 receives the Low signal from the second external output terminal 41 and is controlled so as to shift to the sleep mode when a predetermined time has elapsed.

  Further, when the magnetic sensor 8 described with reference to FIGS. 7 to 9 and FIGS. 12 to 14 is incorporated in the foldable mobile phone 10 shown in FIG. 4, the magnetic sensor 8 in the state shown in FIG. When the first magnetic field strength of the external magnetic field H acting on the first magnetoresistance effect element 23 is + H1, as shown in FIG. 13, the signal output from the first external output terminal 40 changes from High to Low, A Low signal (first detection signal) is transmitted into the control unit 17 shown in FIG. When the control unit 17 receives a Low signal from the first external output terminal 40, the control unit 17 performs control so that the call mode is put on hold.

  When the display housing 11 and the operation housing 12 are opened from the state of FIG. 5 and the magnetic field strength of the external magnetic field H acting on the first magnetoresistive effect element 23 becomes + H2, it is output from the first external output terminal 40. The signal to be changed from Low to High, and the High signal is transmitted into the control unit 17 shown in FIG. When receiving a High signal from the first external output terminal 40, the control unit 17 is controlled to release the hold mode and return to the call mode.

  Further, as shown in FIG. 6, when the display housing 11 and the operation housing 12 of the foldable mobile phone 10 are closed, the second magnetic field strength of the external magnetic field H acting on the second magnetoresistive effect element 28 is + H3. As shown in FIG. 14, the signal output from the second external output terminal 41 changes from High to Low, and the Low signal (second detection signal) is transmitted into the control unit 17 shown in FIG. The When receiving a Low signal from the second external output terminal 41, the control unit 17 is controlled to shift to a mode for disconnecting a call.

  As described above, the notebook personal computer 1 and the folding mobile phone 10 are presented as electronic devices in FIGS. 1 to 6, but the electronic device may be other than the notebook personal computer 1 and the folding mobile phone 10. For example, the first main body and the second main body are not of an openable / closable type in which the first main body and the second main body rotate via a hinge part, but the distance between the first main body and the second main body varies, and the distance is detected in two or more stages. For example, it can also be used for a wiper mechanism or a seat position detection unit.

  Further, in the above embodiment, the detection of the external magnetic field has two stages, but it may have three or more stages. In such a case, it can be achieved by providing three or more magnetoresistive elements having different sensitivities to the magnetic field strength of the external magnetic field in the same direction and assembling these magnetoresistive elements in separate bridge circuits.

  In addition to the GMR element, the element for detecting the external magnetic field may be an AMR element using an anisotropic magnetoresistive effect (AMR) or a TMR element using a tunnel magnetoresistive effect (TMR). It can also be applied to Hall elements.

  However, in this embodiment, it is preferable to use a GMR element or a TMR element. By adjusting the interlayer coupling magnetic field Hin, it is possible to easily obtain the RH curve shown in FIG. 12, and to form a plurality of magnetic detection elements having different magnetic sensitivities with respect to the magnetic field strength change of the external magnetic field H in the same direction. is there. In addition, a GMR element or a TMR element can easily detect a minute magnetic field, and as shown in FIGS. 2 and 3, magnetic detection in a slightly opened state can be appropriately performed, and the opening / closing distance between the first body and the second body can be increased. Easy to detect in multiple stages.

A perspective view of a notebook personal computer (electronic device), The side view of the said notebook personal computer which shows the state on the way from the opened state to closing the notebook personal computer of FIG. A side view of the notebook personal computer showing a state in which the notebook personal computer is closed, Plan view of a foldable mobile phone (electronic device), The side view of the said foldable mobile telephone which shows the state in the middle from the open state to the close of the foldable mobile telephone of FIG. Side view of a foldable mobile phone showing the foldable mobile phone closed, Circuit diagram of a magnetic sensor built in an electronic device, The top view of the magnetic sensor of this embodiment, Sectional drawing of the magnetoresistive effect element (GMR element) incorporated in the said magnetic sensor, The partial block diagram of the notebook type personal computer in this embodiment, Partial block diagram of a foldable mobile phone in the present embodiment, A graph showing RH curves of the first magnetoresistive element and the second magnetoresistive element; A graph showing a relationship between an external magnetic field and a voltage value after shaping based on a change in electrical resistance of the first magnetoresistance effect element; A graph showing a relationship between an external magnetic field and a voltage value after shaping based on a change in electrical resistance of the second magnetoresistance effect element;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Notebook type personal computer 2, 11 Display housing 3, 12 Operation housing 4, 20 Display unit 5 Keyboard 7 Magnet 8 Magnetic sensor 9, 17 Control unit 10 Folding mobile phone 13 Hinge unit 18 Hold voice unit 19 Operation unit 21 Resistive element 22 Integrated circuit (IC)
23 1st magnetoresistive effect element 24 1st fixed resistance element 25 1st output extraction part 26 1st series circuit 27 2nd fixed resistance element 28 2nd magnetoresistive effect element 29 2nd output extraction part 30 2nd series circuit 31 1st 3 fixed resistance element 32 4th fixed resistance element 33 3rd output extraction part 34 3rd series circuit 35 Differential amplifier 36 1st switch circuit 38 Comparator 39 Input terminal 40 1st external output terminal 41 2nd external output terminal 42 Earth terminal 43 Second switch circuit 46, 47 Latch circuit 48 Third switch circuit 53 Clock circuit 62 Antiferromagnetic layer 63 Fixed magnetic layer 64, 67 Nonmagnetic intermediate layer 65 Free magnetic layer 66 Protective layer 70 Substrate Hin1, Hin2 Interlayer coupling magnetic field

Claims (10)

A first main body and a second main body, the interval between the first main body and the second main body being variable;
A non-contact type magnetic sensor provided with a magnetic detection element capable of detecting an external magnetic field emitted from the magnet on one of the first main body and the second main body, and the other;
The magnetic sensor has at least the first distance of the external magnetic field when the first distance between the magnet and the magnetic detection element becomes a first distance with the first body and the second body open. And detecting the first detection signal when the second distance between the magnet and the magnetic detection element becomes a second distance smaller than the first distance. Detecting a magnetic field intensity based on the distance and generating a second detection signal,
An electronic apparatus comprising: a control unit capable of shifting to a predetermined mode based on the first detection signal and the second detection signal.   The magnetic sensor opens the first main body and the second main body separately from the second detection signal used for detecting the open / close between the first main body and the second main body and the open / close detection. The electronic device according to claim 1, wherein the first detection signal for detecting an intermediate state from the state to the closing is generated. The electronic device is a notebook personal computer including a display unit in the first main body and an operation unit in the second main body,
In use, when the distance between the first main body and the second main body is moved from the open state to the closing direction to reach the first distance, the consumption is simpler than the sleep mode based on the first detection signal. Transition to power reduction mode,
3. The electronic device according to claim 1, wherein when the second distance is reached, the electronic apparatus shifts to the sleep mode based on the second detection signal.   The said control part is controlled so that the said power consumption reduction mode is cancelled | released and it can return to the said use state, if the 1st main body and the 2nd main body are opened again from the said 1st distance. Electronics.   5. The electronic device according to claim 3, wherein in the power consumption reduction mode, control is performed so that the display on the display unit disappears.   The electronic apparatus according to claim 5, wherein in the power consumption reduction mode, the backlight provided on the back side of the display unit is controlled to be turned off. The electronic device is a foldable mobile phone including a display unit in the first main body and an operation unit in the second main body,
In the call state, when the distance between the first main body and the second main body is moved from the open state to the closing direction and the first distance is reached, the call shift mode is shifted to the call holding mode based on the first detection signal,
The electronic device according to claim 1, wherein when the second distance is reached, the electronic device shifts to a call disconnect mode based on the second detection signal.   The electronic device according to claim 7, wherein the control unit performs control so that when the first main body and the second main body are opened again from the first distance, the call hold mode is canceled and the call state can be restored. machine.   The magnetic sensor has a first magnetoresistive element and a second magnetoresistive element that use a magnetoresistive effect having different magnetic sensitivities with respect to the magnetic field strength of the external magnetic field from the same direction, and the first magnetic The first detection signal is generated based on a change in electrical resistance value of a resistive effect element, and the second detection signal is generated based on a change in electrical resistance value of the second magnetoresistive effect element. 9. The electronic device according to any one of 8.   The electronic device according to claim 9, wherein each detection signal is generated by a common threshold value.

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