基于FPGA的高分辨率红外触摸屏的设计

The design of touch-screen with high resolution infrared based on FPGA

红外触摸的主要缺点是分辨率低下和易受到光干扰,从而不能实现准确定位。为了提高红外触摸屏的分辨率,准确确定触摸点的位置,通过对红外发光管和红外接收管在触摸时的特性进行分析,得知在触摸时,触摸会对某个邻域内的多个红外接收管造成影响,同时其影响因子存在差异。通过对红外接收管的模拟信号进行A/D转换,使其成为数字信号。再用所得的数字信号来构造影响因子,通过信号处理理论和模糊控制理论来构造线性函数的方法来实现触摸位置的确定。此外,还介绍了该红外触摸屏的硬件组成及其设计。通过对硬件平台的实验证明,在无强光干扰下,该红外触摸屏能够达到的分辨率为0.5 mm。

The main defects of infrared touch screen are low resolution and easily to be effected by light,which makes it can＇t realize the accurate positioning.In order to improve the infrared touch screen resolution,accurately determine the position of the touch point,through the infrared light emitting tube and infrared receiving tube in touch when the characteristics are analysised,which Shous that touch could cause different infrared receiving tube and have different result in a neighborhood,at the same time,they have different impact factor.By the A/D conversion the analog signal received from the infrared receiver is to be a digital signal.The digital signal is used to construct the impact factor.At last,by signal processing theory and fuzzy control theory to construct a linear function of the methods to achieve the touch location determination.In addition,the infrared touch screen hardware components and their design are described.Through the hardware platform of experiments show that in the absence of light interference,the infrared touch screen to achieve a resolution of 0.5 mm.