| 摘要 |
<p>A pressure-sensitive resistance tablet on which its own threshold value (VTR) for pen-on detection can be set and the detection is made with sufficiently low contact resistance irrespective of the position (P) at which the tablet is touched. A reference detection voltage (VCC) is applied to a resistance plate on the positive side through an adjustment resistor (RP) and another resistance plate is grounded. A voltage drop across the adjustment resistor (RP) is called a first potential difference (VA) and a voltage drop across the contact resistance (r) is called a second potential difference (VB). When they are compared with each other, the contact resistance (r) and the resistance value of the adjustment resistor (RP) can be compared. When the resistance value of the adjustment resistor (RP) is set at a resistance value (contact resistance threshold value rC) suitable for recognition of pen-on, the pen-on detection threshold value (VTR) determined from the first potential difference (VA) can be easily set. When this pen-on detection threshold value (VTR) and the second potential difference (VB) are compared and judgement is so made that the resistance plate is pressed when the second potential difference (VB) drops below the pen-on detection threshold value (VTR), a touch on the resistance plate can be recognized when the contact resistance (r) reaches the contact resistance threshold value (rC) without being affected by the position of contact.</p> |
