JP5352289B2 - Electronics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic apparatus which specifies a broken part caused by a load, when the load such as a shock is applied and which securely detects breakage of a substrate. <P>SOLUTION: By having a recess 11g formed inside a hole for inserting a screw fixing a slot unit 4 to the substrate 11, cracks are made to occurs preferentially in the recess 11g than for a hole, when a load such as the shock is applied to the slot unit 4 from the outside. Namely, the occurrence part of the crack can be specified. Thus, occurrence of the crack can be detected, without fail, and protection processing can be performed by forming a conductive pattern 12 in the vicinity of the recess 11g. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an electronic device in which an electronic component is fastened and fixed to a substrate.

  In recent years, a slot unit in which a card (hereinafter referred to as a PCMCIA card) compliant with a PCMCIA (Personal Computer Memory Card International Association) standard can be attached to an information processing apparatus such as a notebook personal computer (hereinafter referred to as a notebook personal computer). It is often equipped with. The PCMCIA card contains a semiconductor element that performs signal processing and a semiconductor element that can record various types of information. In the past, PCMCIA cards were often used as recording media that allow users to record information arbitrarily. Recently, however, PC cards with built-in communication circuits and antennas and capable of wireless communication have also appeared. ing. In many cases, such a PCMCIA card capable of wireless communication has a configuration in which an antenna portion protrudes from a notebook computer in a state in which the PCMCIA card is mounted on the notebook computer so that information can be transmitted and received satisfactorily.

  If such a notebook personal computer is accidentally dropped on the floor or the like, and the PCMCIA card protruding from the notebook personal computer collides with the floor or the like, the slot unit may be damaged. Since the slot unit is generally fastened and fixed to the electric circuit board in the notebook computer with a screw, when an impact is applied to the notebook computer as described above, the impact is transmitted to the board through the screw. For this reason, the screw holes in the substrate often crack.

Patent Document 1 discloses a positioning structure for a case that houses a circuit board of an electronic device. Patent Document 2 discloses an apparatus that detects a relative position shift with respect to a substrate in which no crack is generated, and detects a crack in the substrate. Patent Document 3 discloses an apparatus in which an electrophotographic apparatus such as a copying machine is provided with a groove or the like that generates a crack at a specific position due to thermal expansion of the heating body in order to quickly detect an abnormal temperature rise of the heating body. ing. Patent Document 4 discloses a configuration in which a sensor is mounted by improving a circuit board mounting structure of an electronic device. Patent Document 5 discloses a stress signal measurement sensor and apparatus for a structure such as a substrate of an electronic device.
Japanese Utility Model Publication No. 63-147876 Japanese Patent Application Laid-Open No. 08-335619 Japanese Patent Laid-Open No. 08-137303 JP 2008-085274 A Japanese Patent Laid-Open No. 08-086707

  In the configurations disclosed in Patent Documents 1 to 5, when a load such as an impact is applied to the device, it is not possible to specify a damaged portion in the substrate, so that the breakage detecting unit reliably detects the breakage of the substrate. It was difficult. In order to detect the breakage of the substrate with certainty, it is necessary to dispose the breakage detection means at all the places where the breakage may occur (around the perimeter of the screw hole), which reduces the space efficiency on the substrate. There was also a problem.

  An object of the present invention is to provide an electronic device capable of specifying a breakage point caused by a load when a load such as an impact is applied and detecting a breakage of a substrate with certainty.

The electronic device of the present invention is an electronic device including a substrate on which electronic components are mounted, and the substrate is formed in a hole portion having an inner diameter through which a fastening member can be inserted and an inner periphery of the hole portion. A concave shape portion ; a conductive pattern disposed in the vicinity of the concave shape portion; and a sensor for energizing the conductive pattern and detecting a conductive state of the conductive pattern based on a voltage variation in the conductive pattern . Is.

  According to the present invention, it is possible to specify a portion that is damaged when a load such as an external impact is applied, and thus it is possible to reliably detect the breakage of the substrate by the breakage detection means.

  In the electronic device of the present invention, it is possible to employ a configuration in which a breakage detecting means capable of detecting breakage of the substrate is provided in the vicinity of the concave portion. By setting it as such a structure, it can detect that the external load was applied with respect to the electronic device and the concave part was cracked.

  In the electronic device according to the aspect of the invention, the breakage detection unit energizes the conductive pattern arranged in the vicinity of the concave portion and the conductive pattern, and the conductive state of the conductive pattern is based on a voltage variation in the conductive pattern. It is possible to adopt a configuration provided with a sensor for detecting. With this configuration, when an external load is applied to an electronic device and a crack is generated in the concave portion, it is detected that the concave portion is cracked based on the voltage variation of the conductive pattern. can do.

  In the electronic device according to the aspect of the invention, the electronic component is a slot unit to which a card-like medium can be attached and detached, and the concave portion is in the vicinity of the back side in the insertion direction of the card-like medium with respect to the slot unit in the hole portion. It can be set as the structure currently formed in the said board | substrate. By adopting such a configuration, when a load in the insertion direction into the slot unit is applied to the card-like medium mounted in the slot unit, the concave portion is preferentially damaged over the hole portion. Can do. Therefore, the breakage detection means can reliably detect the breakage of the hole.

  In the electronic device according to the aspect of the invention, the hole has an arc-shaped portion on at least a part of an inner periphery, and the concave-shaped portion has an arc-shaped portion on at least a part of the inner periphery. The radius of curvature of the arc-shaped portion may be smaller than the radius of curvature of the arc-shaped portion of the hole. By setting it as such a structure, when a load is applied to an electronic device from the outside, a concave-shaped part can be damaged preferentially rather than a hole. Therefore, the breakage detection means can reliably detect the breakage of the hole.

(Embodiment)
[1. (Configuration of electronic equipment)
FIG. 1 is a perspective view showing an appearance of a notebook personal computer which is an example of the electronic apparatus according to the present embodiment. FIG. 2 is a perspective view showing a state in which a card conforming to the PCMCIA standard is inserted into the slot unit of the notebook personal computer. Note that in this embodiment, a notebook personal computer is used as an example of an electronic device, but a slot unit including a card slot into which a card containing a semiconductor element can be inserted, such as a mobile phone terminal or a portable game machine. Any electronic device equipped with

  As shown in FIG. 1, the notebook computer includes a first housing 1 having an electric circuit board on which an information processing circuit is mounted, a hard disk drive, and the like, and a second housing 2 having a liquid crystal display 2a. I have. The 1st housing | casing 1 and the 2nd housing | casing 2 are supported by the hinge part 3 so that rotation is mutually possible. By rotating the second casing 2 from the position (first state) shown in FIG. 1 in the direction indicated by the arrow A, the liquid crystal display 2a and the keyboard 5 are shifted to the second state in which they face and face each other. be able to. In addition, when the surface of the first housing 1 facing the second housing 2 in the second state is the upper side, a keyboard capable of inputting various characters is provided on the upper surface 1a of the first housing 1. 5 and a pointing device 6 capable of moving the cursor displayed on the liquid crystal display 2a to a desired position. An information signal input / output from the keyboard 5 or a hard disk drive is subjected to predetermined processing by an information processing circuit (not shown), and is converted into, for example, a display signal displayed on the liquid crystal display 2a. Further, a slot unit 4 having an insertion / removal port through which a card-like medium 20 compliant with the PCMCIA standard (hereinafter referred to as a PCMCIA card) can be inserted / removed is provided on the side surface of the first housing 1.

  The PCMCIA card 20 includes a variety of cards such as a card that incorporates a semiconductor memory element and is used as a storage medium, and a card that incorporates a communication circuit and can be wired or wirelessly communicated. PCMCIA card capable of The PCMCIA card 20 according to the present embodiment includes a substantially plate-shaped main body portion 21 and a substantially rectangular parallelepiped antenna portion 22. The main body 21 incorporates semiconductor elements capable of various signal processing and information storage. In addition, a terminal 21 a is disposed at an end of the main body 21 that faces the antenna unit 22, and can be electrically connected to a connector 40 a (described later) disposed in the slot unit 4. The antenna unit 22 incorporates a communication circuit and an antenna. The PCMCIA card 20 can be inserted into the slot unit 4 in a direction indicated by an arrow B in FIG. 1 from a posture in which the terminal 21 a faces the slot of the slot unit 4. As shown in FIG. 2, when the PCMCIA card 20 is inserted into the slot unit 4, the main body portion 21 is accommodated in the slot unit 4, but the antenna portion 22 is not accommodated in the slot unit 4. It will be in the state which protruded from the housing | casing 1 of 1.

  As shown in FIG. 2, by inserting a PCMCIA card 20 having a communication function into the slot unit 4, the PCMCIA card 20 and the information processing circuit in the notebook computer are electrically connected, and the notebook computer is wirelessly connected. Communication is possible. In the PCMCIA card 20 of the present embodiment, when the antenna unit 22 protrudes from the first housing 1 in the state of being inserted into the slot unit 4, it is possible to improve radio wave reception and transmission sensitivity.

  Hereinafter, the holding structure of the slot unit 4 will be described in detail.

  FIG. 3 is a perspective view of the vicinity of the slot unit 4 inside the notebook computer. FIG. 4 is a plan view of the vicinity of the slot unit 4 inside the notebook computer. FIG. 5 is a cross-sectional view taken along the line ZZ in FIG. The slot unit 4 and the substrate 11 are accommodated in the first housing 1 (see FIG. 1 and the like). However, in order to clearly illustrate the slot unit 4 and the substrate 11 in FIGS. The illustration of the first housing 1 is omitted.

  The slot unit 4 is disposed on the surface 11 a of the substrate 11 disposed in the first housing 1. The slot unit 4 is held on the first housing 1 and the substrate 11 by screws 44a to 44d. That is, the screws 44 a and 44 b are inserted into holes (described later) formed in the substrate 11 and screwed into screw holes (not shown) formed in the first housing 1. The screws 44c and 44d are inserted into holes (described later) formed in the substrate 11 and screwed to the ribs 43c and 43d. Further, the slot unit 4 is electrically connected to a conductive portion formed on the substrate 11 (a connection configuration with the conductive portion is not shown). The slot unit 4 includes a main body 40, a take-out lever 42, ribs 43 a to 43 d, and a grounding part 45.

  The main body portion 40 is formed of a substantially rectangular parallelepiped housing and has a card storage portion 41 having one end opened. The main body 40 is mainly formed of a metal such as aluminum. In addition, a connector 40 a that can be connected to the terminal 21 a of the PCMCIA card 20 is provided on the inner surface of the card storage unit 41 that faces the opening (insertion / removal port) 41 a.

  The take-out lever 42 is arranged so as to be pressed in the direction indicated by the arrow C. The take-out lever 42 is in the position shown in FIG. 4 when the PCMCIA card 20 is not inserted, but by inserting the PCMCIA card 20 into the card storage portion 40 and inserting it to the position where the terminal 21a and the connector 40a are connected. 4 is slightly displaced from the position shown in FIG. When the PCMCIA card 20 is inserted into the slot unit 4, the PCMCIA card 20 can be pulled out in the direction indicated by the arrow D by pressing the take-out lever 42 in the direction indicated by the arrow C. Detailed description of the mechanism for pulling out the PCMCIA card 20 in the direction indicated by the arrow D will be omitted.

  The PCMCIA card 20 can be inserted into and removed from the slot unit 4 by the user. Accordingly, when the PCMCIA card 20 is inserted into the slot unit 4 when the user is charged with static electricity, for example, the terminal 21a may be discharged to the connector 40a. In order to prevent this discharge, the standard stipulates that a ground electrode 45 is provided in the opening 41a into which the PCMCIA card 20 is inserted. Therefore, a leaf spring shape is formed by notching a part of the side surfaces 41b and 41c to the side surface 41b and the side surface 41c opposite to the side surface 41b of the opening 41a where the takeout lever 42 is disposed in the card storage unit 41. A pair of ground electrodes 45 are provided.

  The ribs 43a and 43b are arranged at both ends of the main body 41 in the direction orthogonal to the insertion / removal direction of the PCMCIA card 20. The ribs 43 c and 43 d are arranged at the end of the main body 31 in the insertion / removal direction of the PCMCIA card 20. The ribs 43a and 43b are formed with holes through which the screws 44a and 44b can be inserted, respectively. The ribs 43c and 43d are formed with screw holes into which screws 44c and 44d can be screwed, respectively. Screws 44a and 44b are inserted through holes formed in the ribs 43a and 43b and holes (described later) formed in the substrate 11, and into screw holes (not shown) formed in the first housing 1. The slot unit 4 can be fixed to the first housing 1 by screwing. The screws 44c and 44d are inserted into holes (described later) formed in the substrate 11 and screwed into screw holes (not shown) formed in the ribs 43c and 43d, thereby holding the slot unit 4 on the substrate 11. can do.

  The ribs 43a and 43b are preferably arranged as close to the opening 41a as possible. However, as shown in FIG. 4, a take-out lever 42 is arranged near the side surface 41b of the opening 41a, and both side surfaces 41b and 41c are arranged. A pair of ground electrodes 45 is disposed, and the ground electrode 45 needs to be provided in the immediate vicinity of the opening 41a according to the standard. Therefore, since it is practically impossible to lock the immediate vicinity of the opening 41a in the side surfaces 41b and 41c, the pair of ribs 43a and 43b are disposed at positions adjacent to the take-out lever 42 in the present embodiment.

  As shown in FIG. 5, the substrate 11 is fastened and fixed to the first housing 1 by screws 44 e on the first housing 1.

[2. (Damage detection operation)
FIG. 6 is a plan view of the back surface 11 b of the substrate 11. As shown in FIG. 6, holes 11 c to 11 f are formed in the substrate 11. A screw 44a (see FIG. 4) is inserted through the hole 11c. A screw 44b (see FIG. 4) is inserted through the hole 11d. A screw 44c (see FIG. 4) is inserted through the hole 11e. A screw 44d (see FIG. 4) is inserted through the hole 11f.

  A conductive pattern 12 is formed on the back surface 11 b of the substrate 11. A sensor circuit 13 is mounted on the back surface 11 b of the substrate 11. The conductive pattern 12 and the sensor circuit 13 are electrically connected. A part of the conductive pattern 12 is arranged in the vicinity of the holes 11e and 11f. The sensor circuit 13 applies a constant current to the conductive pattern 12 to monitor the voltage, and monitors the conductive state of the conductive pattern 12 based on the voltage fluctuation. The sensor circuit 13 is connected to a control circuit (not shown) in the notebook computer, and outputs a detection signal to the control circuit when detecting that the conductive pattern 12 is electrically broken. The control circuit includes a central processing unit (CPU) and the like, and controls each unit in the notebook computer.

  The holes 11c and 11d are formed in a substantially circular shape, but the holes 11e and 11f include a recess 11g (described later) in a part of the substantially circular through hole.

  FIG. 7 is an enlarged plan view of the hole 11e. Although detailed illustration and description are omitted, the hole 11f has the same shape as the hole 11e. As shown in FIG. 7, a recess 11g is formed in a part of the inner periphery of the hole 11e. The recess 11g is formed at the end of the hole 11e in the card insertion direction (the direction indicated by the arrow C). The recess 11g is formed in a substantially semicircular shape. When the recess 11g is formed in a substantially semicircular shape as shown in FIG. 7, it is preferable to make the radius of curvature at least smaller than the radius of curvature of the hole 11e. A conductive pattern 12 is disposed in the vicinity of the recess 11g. The broken line in FIG. 7 shows the position of the screw 44c when no impact is applied to the notebook computer.

  Hereinafter, the behavior when a load is applied will be described. As an example of the load, the load when an impact is applied to the PCMCIA card 20 mounted in the slot unit 4 is cited.

  As shown in FIG. 2, if the notebook personal computer is accidentally dropped on the floor or the like with the PCMCIA card 20 inserted into the slot unit 4, the antenna portion 22 protruding from the first housing 1 is placed on the floor or the like. There is a possibility of colliding. Alternatively, the user's hand may accidentally come into contact with the antenna unit 22 when operating an external device such as a mouse operation process or a process of connecting an external display to a notebook computer.

  When the antenna portion 22 protruding from the first housing 1 is collided with the floor or the hand of the user in this way and a load is applied to the PCMCIA card 20 in the direction indicated by the arrow C, the PCMCIA card 20 Since it is held in the slot unit 4 (see FIG. 4), a load in the direction indicated by the arrow C is also applied to the slot unit 4. When a load in the direction indicated by the arrow C is applied to the slot unit 4, a load in the direction indicated by the arrow C is applied to the holes 11c to 11f (see FIG. 6) via the screws 44a to 44d.

  At this time, substantially the same load is applied to the holes 11c to 11f in the direction indicated by the arrow C, but the recess 11g is preferentially distorted and cracks are generated over the holes 11c to 11f. FIG. 8 is a plan view of an essential part in the vicinity of the hole 11e showing a state in which the crack 11h is generated in the recess 11g. That is, in this embodiment, by providing the recess 11g having a radius of curvature smaller than the curvature radius of the holes 11c to 11f, stress is concentrated in the recess 11g when a load is applied to the holes 11c to 11f. Then, the recess 11g is distorted preferentially over the holes 11c and 11d, and the crack 11h is generated.

  Since the conductive pattern 12 is disposed in the vicinity of the recess 11g, the crack 11h generated in the recess 11g may reach the conductive pattern 12. When the conductive pattern 12 is electrically broken by the crack 11h, the voltage of the conductive pattern 12 decreases. The sensor circuit 13 (see FIG. 6) detects that the conductive pattern 12 is electrically broken by detecting a decrease in the voltage of the conductive pattern 12.

  When detecting that the conductive pattern 12 is electrically broken, the sensor circuit 13 outputs a detection signal to a control circuit (not shown). When the detection signal is sent from the sensor circuit 13, the control circuit executes a protection process. The protection process is, for example, a process (shutdown process) for switching the power supply of the notebook computer from on to off. Thus, by executing the shutdown process, it is possible to prevent the notebook personal computer from being continuously used in a state where the substrate 11 is damaged.

[3. Effects of the embodiment, etc.]
According to the present embodiment, the recess 11g is formed on the inner periphery of the hole for inserting the screw, so that when a load such as an impact is applied to the slot unit 4 from the outside, the inner wall of the hole The crack 11h can be generated in the recess 11g preferentially. That is, the occurrence location of the crack 11h can be specified.

  Further, by forming the conductive pattern 12 in the vicinity of the recess 11g, the conductive pattern 12 is broken when a crack is generated, so that the occurrence of a crack can be reliably detected and a protection process can be executed.

  The shape of the recess 11g is not limited to a semicircular shape, and may be a V-shape or the like. The shape of the recess 11g may be any shape that preferentially cracks over a hole where no recess is formed when a load is applied to at least the hole 11e.

  Further, the position where the concave portion 11g is formed in the hole portion 11e is not limited to the rear end portion in the card insertion direction (the direction indicated by the arrow C), and an impact is applied to at least the PCMCIA card 20 mounted in the slot unit 4. What is necessary is just to form in the site | part which receives the impact in the inner surface of the hole 11e when it is done. For example, it is preferably formed on the arrow C side with respect to the alternate long and short dash line F in FIG.

  In this embodiment, when the sensor circuit 13 detects an electrical breakage of the conductive pattern 12, the control circuit executes a protection process for turning off the power of the notebook computer, but the protection process turns off the power of the notebook computer. It is not limited to the processing to make. For example, the liquid crystal display 2a shown in FIG. 1 may be configured to display a message that prompts the user to turn off the notebook computer or a message that prompts the user to repair the notebook computer. . Moreover, when performing the protection process by the shutdown as described above, it is preferable that the shutdown process is performed after giving the user an opportunity to save the data being worked on in the notebook computer. .

  Further, in the present embodiment, as shown in FIG. 6, one conductive pattern 12 is disposed close to both the holes 11e and 11f, but the conductive pattern disposed close to the hole 11e and the hole 11f are arranged. The conductive patterns arranged close to each other may be provided independently. By setting it as such a structure, the hole which the crack entered among the hole parts 11e and 11f can be specified.

  Moreover, in this Embodiment, although the recessed part 11g was formed in the hole parts 11e and 11f, you may form the recessed part 11g in the hole parts 11c and 11d. When the concave portions 11 g are formed in the holes 11 c and 11 d, the conductive pattern 12 is arranged on the surface 11 a of the substrate 11, so that the conductive pattern 12 is arranged at a position hidden by the slot unit 4. Therefore, the dead space below the slot unit 4 can be used effectively, and the space efficiency can be improved. Furthermore, by disposing the sensor circuit 13 below the slot unit 4, the dead space below the slot unit 4 can be used effectively, and space efficiency can be improved.

  In the present embodiment, only one recess 11g is formed in one hole, but a plurality of recesses may be formed in one hole. By forming a plurality of recesses, even if a load is applied in a direction other than the direction indicated by the arrow C, a crack can be generated in any of the plurality of recesses. Therefore, the sensor circuit 13 can detect the application of a load more reliably.

  In the present embodiment, since the substrate 11 is screwed and fixed to the first housing 1 with screws 44e, the substrate 11 and the first housing 1 are rigid bodies. Therefore, when a load is applied in the direction indicated by the arrow C, the load is applied to the ends of the holes 11c to 11f in the direction indicated by the arrow C. However, when the board 11 has a floating structure with respect to the first housing 1, when a load is applied to the slot unit 4 in the direction indicated by the arrow C, the arrow with respect to the board 11 together with the slot unit 4 is applied. A load in the direction shown in C is applied. Therefore, in the hole portions 11c to 11f, a load is applied to the end portion in the direction indicated by the arrow D, and therefore the recess is preferably formed as shown in FIG.

  In FIG. 9, the recess 11m is formed at the end of the hole 11j in the direction indicated by the arrow D. The recess 11n is formed at the end of the hole 11k in the direction indicated by the arrow D. The conductive pattern 12 is disposed in the vicinity of the recesses 11m and 11n. With the configuration shown in FIG. 9, when a load in the direction indicated by the arrow C is applied to the substrate 11, the ends of the holes 11 c, 11 d, 11 j, and 11 k in the direction indicated by the arrow D are screws (not shown). ) And a load is applied. Since the curvature radii of the recesses 11m and 11n are smaller than the curvature radii of the holes 11c, 11d, 11j, and 11k, the stress concentrates and cracks are preferentially formed over the holes 11c, 11d, 11j, and 11k. The protection operation of the notebook personal computer is started when the sensor circuit 13 detects that the conductive pattern 12 is electrically broken due to the crack.

  In this embodiment, a notebook personal computer is used as an example of an electronic device. However, any device including at least a slot unit may be used. For example, it is useful for a PDA (Personal Digital Assistant), a portable game machine, a medical device, and the like. In recent years, PDAs, portable game machines, medical devices, and the like are often provided with a slot unit into which a small memory card can be inserted and removed, and the present invention is useful also in such a slot unit.

  In the present embodiment, the electronic device has been described in which the slot unit is fastened and fixed to the board with screws. However, the electronic component to be fastened and fixed to the board is not limited to the slot unit.

  In this embodiment, a PCMCIA card is taken as an example. However, at least a card-shaped information medium may be used. Further, any electronic device including a slot unit that can be held so that a part of the information medium protrudes from the slot unit when a card-shaped information medium is mounted in the slot unit may be used.

  The substrate 11 in the present embodiment is an example of the substrate in the present invention. The slot unit 4 in the present embodiment is an example of an electronic component in the present invention. Moreover, the hole parts 11c-11f, 11j, and 11k in this Embodiment are examples of the hole part in this invention. Moreover, the recessed part 11g in this Embodiment is an example of the recessed shape part in this invention. Further, the screws 44a to 44d in the present embodiment are an example of a fastening member in the present invention. In addition, the conductive pattern 12 and the sensor circuit 13 in the present embodiment are an example of damage detection means in the present invention.

  The electronic device of the present invention is useful for a device in which an electronic component is mounted on a substrate by fastening means.

The perspective view which shows the external appearance of the electronic device in this Embodiment The perspective view which shows the external appearance of the electronic device in this Embodiment Perspective view of the vicinity of the slot unit Plan view of the vicinity of the slot unit Sectional drawing of the principal part of the ZZ part in FIG. Plan view of the main part of the back side Plan view of the main part near the screw hole A plan view of the main part near the screw hole showing a crack in the recess. Main part plan view showing another configuration example of the substrate

4 slot unit 11 substrate 11c, 11d, 11e, 11f hole 11g recess 12 conductive pattern 13 sensor circuit 20 PCMCIA card 44a, 44b, 44c, 44d screw

Claims (5)

An electronic device including a board on which electronic components are mounted,
The substrate is
A hole having an inner diameter through which the fastening member can be inserted;
A concave portion formed on the inner periphery of the hole ,
A conductive pattern disposed in the vicinity of the concave portion;
An electronic device comprising: a sensor that energizes the conductive pattern and detects a conductive state of the conductive pattern based on a voltage variation in the conductive pattern . The control circuit further includes a CPU connected to the sensor,
When the sensor detects a voltage drop in the conductive pattern, it outputs a detection signal to the CPU;
The electronic device according to claim 1 , wherein the CPU executes a protection process for the electronic device based on a detection signal from the sensor . The electronic device according to claim 2 , wherein the protection process is a shutdown process . A display for displaying images;
The electronic device according to claim 2 , wherein the protection process is a process of displaying a message on the display . The hole is formed in a substantially circular shape,
2. The electronic device according to claim 1 , wherein the conductive pattern is disposed in the vicinity of a position farthest from the center of the hole in the concave portion .

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