# Robot Bionic Vision Technologies: A Review
## 2 Literature Review
### The Development Process of Bionic Vision  
If light from a source object is shone into a dark space through a small hole, an inverted image of the object can be projected onto a screen, such as the opposite wall. This phenomenon is called \"pinhole imaging\". In 1839, [PERSON] of France invented the camera [107], and thus began the era of optical imaging technology. The stereo prism was invented in 1838. By 1880, Miguel, a handmade camera manufacturer in London, UK, had produced dry stereo cameras. At that time, people had early stereo vision devices, but these devices could only store images in films. In 1969, [PERSON] and [PERSON] of Bell Laboratories invented a charge-coupled device (CCD), which is an important component of the camera [108]. A CCD is a photosensitive semiconductor. They can convert optical images into electrical signals. A tiny photosensitive material implanted in the CCD is called a pixel. The more pixels a CCD contains, the higher its picture resolution. However, the function of the CCD is similar to that of a film: it converts the optical signal into a charge signal. The current signal is amplified and converted into a digital signal to realize the acquisition, storage, transmission, processing, and reproduction of the image. In 1975, camera manufacturer Kodak invented the world's first digital camera using photosensitive CCD elements six years earlier than Sony [109]. At that time, the camera had 10,000 pixels, but the digital camera was still black and white. Surprisingly, in 2000, Sharp's J-SH04 mobile phone was equipped with a 110,000 pixel micro CCD image sensor. Thus began the age of phone cameras. People can now carry cameras in their pockets [110,111]. The development of vision equipment and bionic vision technology in Figure 5.  
Early image systems laid a solid foundation for modern vision systems and the future development of imaging techniques and processing. By consulting and searching through vast and relevant technical literature, it was found that the current industry mainly includes two technical schools: the bionic binocular vision system and the bionic compound eye vision system. The main research scholars are [PERSON], [PERSON], [PERSON], [PERSON], and [PERSON]. According to WHO statistics, 285 million people worldwide are visually impaired. Of these, 39 million are classified as blind [112]. Scientists have been working to develop bionic eye devices that can restore vision. [PERSON] has studied this topic for several decades. His team successfully developed a bionic vision system called Gennaris [113]. Figure 5: The development of vision equipment and bionic vision technology. Because the optic nerve of a blind person is damaged, signals from the retina cannot be transmitted to the \"visual center\" of the brain. The Gennaris bionic vision system can bypass damaged optic nerves. The system includes a \"helmet\" with a camera, wireless transmitter, processor, and 9 \(\times\) 9 mm patch implanted into the brain. The camera on the helmet sends captured images to the visual processor, where they are processed into useful information. The processed data are wirelessly transmitted to the patch implanted into the brain and then converted into electrical pulses. Through microelectrode stimulation, images are generated in the visual cortex of the brain. Professor [PERSON] of the Hong Kong University of Science and Technology and his team successfully developed a bionic eye based on the hemispherical retina of a perovskite nanowire array. This bionic eye can achieve a high level of image resolution and is expected to be used in robots and scientific instruments [114,115]. In 1998, the Artificial Intelligence Laboratory at MIT created a vision system for the Kismet robot. However, at that time, robot vision could only achieve a considerably simple blinking function and image acquisition. Since then, significant progress has been made in binocular robot vision systems.