摘要传统视力检测手段在很大程度上依赖于专业人员的现场监督指导，不仅浪费人力，同时检测结果会或多或少受到人为因素的干扰，导致检测结果无法做到绝对的准确和公平。

自动视力检测系统克服了以上传统视力检测的不足。基于传统的人工验光方式，本系统在所有需要人为协助的环节上实现了智能化、自动化。该系统利用液晶屏显示视力表中各级“E”字母，用户通过智能手机打开针对该系统设计的app，并通过app中的方向键判断“E”的方向，从而进行视力检测。该系统从“E”字母方向给出、用户选择、系统纠错、错误统计到结果产生，全程自动化，测量结果客观公正，所有功能均可由用户控制。系统基于嵌入式开发架构，采用uboot为底层，linux为操作系统，Qt文件系统作为人机交互层的基本框架，并利用linux操作系统提供的API、多进程、进程间通信、信号机制以及对底层的驱动支持进行应用程序及驱动程序的开发，该系统最终在嵌入式开发板iTop4412上成功运行。87128

自动视力检测系统旨在实现准确测量视力的同时，提高用户体验度。系统实现了与用户的实时交互，字符显示清晰、语音播报精准，结果计算快速，真正满足了用户对于新型视力检测手段的需求。

毕业论文关键字：嵌入式系统；视力检测；蓝牙交互 

Abstract Traditional means of vision detection which is not only a waste of manpower, but also the test result will be more or less affected by interference of human factors thus resulting  in inaccurate and unfair test results dependents on professional personnel supervision and guidance in a large extent。

Automatic vision detection system overcomes the shortcomings of traditional vision detection。 The automatic vision detection system is based on embedded architecture。 It comes from traditional manual optometry method and is intelligent and automatic in most of cases of which needing human assistance。 The system displays all levels of letter "E" by LCD, the user open the custom-built system through the smart mobile phone, and determine the direction of letter "E" by app’s direction keys to finish visual detection。 The system is full automation from the way letter "E" direction is given, user selection, system error correction, error statistics and results produced。 The measurement results are objective and impartial and all functions of system can be controlled by the user。 The system is based on embedded development architecture, which uses uboot as the substrate, Linux as the operating system, Qt file system as the basic framework of human-computer interaction layer, and API, multi process, inter process communication, signal mechanism and the underlying driver support provided by Linux operating system for the application and development of the driver, the system runs successfully in the embedded development board named for iTop4412。

Automatic vision detection system aim not to only achieve accurate measurement of visual acuity but also improve the users' experience degree。 The system realizes the real-time interaction with the user contribute to characters displayed well, voice broadcasted accurately, results calculated fast, which really meet the demand for new vision detection means。

Key Words: Embedded; Vision inspection; Bluetooth interaction

目 录

第一章 绪论 1

1。1 选题背景 1

1。2 系统设计的目标 2

1。3 课题研究的内容和意义 2

1。4 本章小结 3

第二章 系统需求及可行性分析