問78
頻出度★☆☆
スキャナの説明として, 適切なものはどれか。
平成25年度 秋期 ITパスポート試験 問78
This question's explanation and your answers so far.
解説
問 78
- ア
正解 The correct answer is ア. A scanner (image scanner) is an input device that shines light on the surface of a document while scanning it, reads the reflected light with light-receiving elements such as CCDs, and converts the brightness and color information into digital data (image data). Choice ア, “It scans a paper surface to read an image and converts it into digital data”, states exactly this operating principle and role, so it matches the definition of a scanner perfectly. Typical uses include digitizing photos and documents, and the copy and fax-sending parts of a multifunction printer. The key point is that what a scanner handles is not a position on a screen or an amount of movement, but the image on the paper itself.
Incorrectイ
“It reads the amount, direction, and speed of movement using a light emitter and a light receiver on its underside” describes an optical mouse. It shines light on the desk surface, detects its own movement from changes in the reflected light, and moves the pointer; both its purpose and its output differ from those of a scanner, which reads the image on paper and turns it into digital data. Only the fact that light is used is similar, which makes this a trap.
Incorrectウ
“It uses a pen-shaped tool to input a position on a board surface” describes a pen tablet (graphics tablet, digitizer). You trace on a flat board with a dedicated pen, and the device inputs those coordinates; it is used for entering handwritten characters and illustrations. What is entered is positional (coordinate) information, not an image read from a document.
Incorrectエ
“It inputs a position on the screen by touching it with a finger” describes a touch panel. Like those on smartphones or ticket machines, it is integrated with the display device and detects the position touched on the screen; it is an input device with no function for taking in a paper document as an image.
ここがポイント
- A scanner (image scanner) is an input device that scans a paper surface with light, reads the image, and converts it into digital data.
- Distinguishing it from pointing devices is the key. An optical mouse detects the amount, direction, and speed of its own movement; a pen tablet (digitizer) inputs a position on a board surface with a pen; a touch panel inputs a position on the screen with a finger. All of these input position and movement, so their role differs from that of a scanner, which reads images.
用語