摘要
ITO材料与玻璃基板的透射与反射系数相近而使高速扫描CCD很难采集到高对比度图像,电容触摸屏的ITO电路上下双层结构使光源倾角与相机倾角不平行时照明光经过多次透射与反射后会出现无序叠加。采用光源倾角与相机倾角平行的透射照明方式能避免光强无序叠加,并能提高玻璃基板图像和ITO图像的对比度,光照强度优化实验表明:光强较弱时CCD曝光不足将导致图像过暗并存在横向条纹干扰,随光强增大图像灰度直方图双峰现象凸显,在光照等级达到200时达到最佳,之后变化不明显。
The transmission and reflection coefficients of ITO materials and glass substrate are similar,so high contrast image is difficult to collect by high speed scanning CCD. ITO circuit of capacitive touch screens is divided into upper and lower double. Illumination light will show disorderly superposition phenomenon,after several transmission and reflection,when the light angle is not parallel with camera angle. Light intensity disorderly superposition phenomenon could be avoided,and contrast value between the glass substrate and ITO images was increased when transmission image way was used,in which the light source was parallel with the camera inclination angle. The illumination intensity optimization experiment shows that CCD insufficient exposure will cause the image too dark; with the light intensity increase,the image gray histogram two-peak phenomenon is obvious; the two-peak phenomenon is most obvious when light intensity reachs 200; then the two-peak phenomenon has no obvious change when light intensity is higher than 200.
出处
《机床与液压》
北大核心
2016年第10期41-44,共4页
Machine Tool & Hydraulics
基金
2014年广东省教育厅科技创新项目(2013KJCX0195)
广东省省级科技计划项目(2013B090600052)
