問76
頻出度★☆☆
スマートフォンなどのタッチパネルで広く採用されている方式であり, 指がタッチパネルの表面に近づいたときに, その位置を検出する方式はどれか。
令和6年度 ITパスポート試験 問76
This question's explanation and your answers so far.
解説
問 76
Incorrectア
The pressure-sensitive type (resistive film type) detects position by physically pressing with a finger or pen so that two layers of transparent electrodes come into contact, using the electrical change produced by that pressure. It does not respond merely when a finger approaches; pressing force is required, so it does not match the condition in the question.
Incorrectイ
The optical type runs light such as infrared around the edge of the screen and detects the position where the light is blocked by a finger or the like. Because it relies on the blocking of light rather than a change in capacitance, it differs from the question's description of a method widely used in smartphones.
- ウ
正解 The correct answer is “ウ Capacitive type.” The capacitive type uses the fact that the capacitance (the ability to store electric charge) of the electrodes formed on the panel surface changes when a finger, which is a conductor, comes near, and it detects the position where that change occurs as coordinates. It responds when a finger touches the surface or even merely approaches it, and it can also detect several fingers at once (multi-touch), so it is the most widely adopted method for the touch panels of smartphones and tablets. It satisfies both conditions in the question, namely “detecting the position when a finger approaches the surface” and “widely adopted in smartphones.”
Incorrectエ
The electromagnetic induction type detects the position of the pen tip by using the electromagnetic induction that arises between a dedicated pen (stylus) and a coil on the panel side, and it is used in pen tablets and similar devices. It does not apply to a question that presupposes operation with a finger.
ここがポイント
- The capacitive type detects position from the change in capacitance caused by a finger approaching, and because it supports multi-touch, it is widely adopted in smartphones and tablets.
- The point being tested is to distinguish and grasp the principles and uses of the main touch-panel detection methods (pressure-sensitive/resistive film, optical, capacitive, and electromagnetic induction).
用語