| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for detecting the illegal removal of the lid from an electronic apparatus with a simple and inexpensive configuration without requiring a backup power source such as a battery. SOLUTION: A substrate 3 is fixed to the inner part of the case 1 of the electronic apparatus so as to face the lid 2. A resistance film pattern 4 is formed on the surface of the substrate. A washer 8 is held between the substrate 3 and the lid 2. In this state, the lid 2 is fixed to the case 1 with a fixing screw 12 and the sliding element 10 of the washer 8 is brought into contact with the resistance film pattern 4. Then, a variable resistance is composed of the resistance film pattern 4 and the sliding element 10. Since the amount of rotation of the washer 8 when the fixing screw 12 is screwed or loosened is variable, the position of the sliding element 10 becomes different from the previous position when the fixing screw 12 is operated. The removal of the lid 2 is detected based on the difference. COPYRIGHT: (C)2007,JPO&INPIT
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