The image sensor can be said to be the eye of an electronic product, providing machine vision for various applications. Although this is not a new product, its related technology is still evolving, making the resolution of the image sensor higher and the image quality better. With lower power consumption, let's take a look at the latest developments!

Global shutter avoids jelly effect

Image sensors have been developed for many years. The earliest use of CCD technology is applied to a wide variety of cameras, but as portable devices pay more attention to the use of products and the digitalization of products, it is more energy-efficient. Easy-to-integrate CMOS technology is becoming mainstream, and is widely used in a wide range of electronic products such as digital cameras, camcorders and mobile phones.

The above two image sensing technologies do not have much advantages and disadvantages in image quality. However, under the same conditions, CMOS photosensitive components use relatively few components, resulting in lower power consumption and higher data throughput speed than CCD. Since the digital camera CMOS sensor can be directly fabricated on the motherboard circuit, its signal transmission distance is shorter than that of the CCD, and the capacitance, inductance and parasitic delay are reduced. In addition, the manufacturing cost of CMOS is also lower than that of CCD sensors, so the phenomenon that CMOS technology dominates is almost already on the market.

In the past, CMOS sensors used a rolling shutter to produce a bad Jello Effect when shooting a high-speed moving object. This is because the CMOS sensor requires progressive scanning when recording photoelectric signals. The form is to record images from left to right and top to bottom point by point, which feels a bit like laying down the curtains. Therefore, there must be a time difference between reading the first line signal and the last line of the signal. When shooting a fast moving scene, the image is tilted and deformed due to the time difference, which leads to the famous jelly effect.

How to solve the jelly effect? That is, you don't want to record data line by line, but this will affect the performance of CMOS in high speed, high efficiency, low power consumption. However, with the improvement of processor and memory technology in recent years, the two can no longer be done. The matter, therefore, the birth of the Global Shutter.

The following is an example of an AR0134 image sensor from ON Semiconductor for use in an Oculus Rift VR device. This is an industrial grade 1/3" megapixel global shutter sensor for bar code scanning, 3D scanning, position tracking. Applications such as virtual reality (VR), augmented reality (AR), biometrics, and machine vision, with a 3.75μm pixel design and resolutions up to 1.2Mp (1280 x 960) for excellent low-light performance and linearity Capture technology, support 720p60fps HD video output, support video / single-frame mode, flexible skip mode, with on-chip auto exposure, automatic black level calibration and statistics engine, support for parallel and serial output, this is the third generation Global shutter technology provides the highest energy-efficient global shutter pixels with sensitivity up to 6.1V/lux-sec, 45fps at full resolution, 720p60fps video support, and an external LED or flash. In addition, context switching The Switching feature supports applications with different imaging needs, using a single source for efficient operation.

With the help of virtual reality and augmented reality applications, the development of the image sensor market is more rapid. With the advancement of technology, the image sensor has improved in terms of shooting quality, power consumption and performance, which will make the machine The eyes become sharper, the application is more extensive, and the market will grow faster.

Editor in charge: Zhu Xi