Nearsighted photodetector and camera

This papar proposes an optical camera which detects not the distant objects but the close objects; namely Nearsighted camera. In general, the optical camera can detect not only the close object but also the distant objects located in front of the camera. However, when we consider some tasks for the robots such as the obstacle avoidance and the object holding, the distant objects sometimes interfere the task executions. The procedures may become easier if the robot can detect only the close objects related to the tasks. Although there are some studies about the object recognition utilizing the difference of the distance from the camera to the objects such as depth from (de)focus and stereo vision, the computational cost is large. The authors, therefore, focus on close object detection and aim at developing an optical camera for close object detection. Though there are some active devices for detecting the close object such as ultrasonic distance sensor and infrared radiation sensor, there are few passive devices for the close object recognition. We explain the design method of the fundamental devices in the nearsighted camera; and show the prototype of the nearsighted camera. To evaluate the features of nearsighted camera, we conduct the experiments for confirming the performance of the fundamental device in the nearsighted camera. We also conduct the experiments for detecting some characters in near field. The experimental results show that nearsighted camera reacts not to the distant objects but to the close objects.