扫描引擎

扫描引擎是词法分析器中的关键机电光学组件，通过先进成像技术从物理文档捕获文本或代码。它结合光源、透镜、传感器和运动控制系统，将印刷字符转换为数字信号，以供后续解析和词法单元化。该组件通过确保精确的字符识别和最小化光学畸变，决定整个词法分析过程的准确性、速度和分辨率。

扫描引擎通过LED或激光光源照亮文档表面，然后通过精密透镜将反射光捕获到CCD或CMOS传感器阵列上。传感器将光强度变化转换为电信号，再由模数转换器数字化。步进电机或线性执行器控制文档移动以进行逐行扫描，而板载处理器在将干净的数字数据传输到词法分析器的处理单元之前，执行初步的噪声降低和边缘检测。

The scanner engine operates by illuminating the document surface with LED or laser light sources, then capturing reflected light through precision lenses onto a CCD or CMOS sensor array. The sensor converts light intensity variations into electrical signals, which are digitized by an analog-to-digital converter. A stepper motor or linear actuator controls document movement for line-by-line scanning, while onboard processors perform initial noise reduction and edge detection before transmitting clean digital data to the lexical analyzer's processing unit.