Kazunari Kawabata

A 1.8e − temporal noise over 90dB dynamic range 4k2k super 35mm format seamless global shutter CMOS image sensor with multiple accumulation shutter technology

A low noise and high dynamic range global shutter (GS) CMOS image sensor (CIS) with multiple accumulation shutter technology is described. The pixel having a 6.4μm pitch, achieved 1.8e− temporal noise and full well capacity of 70,000e− with charge domain memory, corresponding to 92dB dynamic range in 30fps operation. In the signal readout procedure, light exposure and signal readout are executed simultaneously, hence the seamless signal accumulation can be carried out.

4.5 A 1.8e rms − temporal noise over 110dB dynamic range 3.4µm pixel pitch global shutter CMOS image sensor with dual-gain amplifiers, SS-ADC and multiple-accumulation shutter

CMOS image sensors (CIS) with global shutter (GS) function are required in a variety of areas, including broadcasting, automobile, drones, and surveillance applications. For these applications, GS CISs are needed to avoid rolling shutter (RS) distortion. These applications also benefit from the high image quality and high frame rates of GS CISs [1–3]. To realize a GS CIS, a memory structure and additional MOS transistors are necessary. Due to this increase in the number of components, photodiode area is restricted. Therefore, sensor performance (e.g., noise, sensitivity, and saturation) of GS CISs has generally remained inferior to that of RS sensors. To break down this constraint, we introduce a multiple-accumulation shutter technique for GS CISs. Furthermore, we combine the column single-slope ADCs with dual-gain amplifiers (SSDG-ADC) [4] to implement this technique effectively, while also achieving low power consumption and a high frame rate.

Development of Gentle Slope Light Guide Structure in a 3.4 μm Pixel Pitch Global Shutter CMOS Image Sensor with Multiple Accumulation Shutter Technology

CMOS image sensors (CISs) with global shutter (GS) function are strongly required in order to avoid image degradation. However, CISs with GS function have generally been inferior to the rolling shutter (RS) CIS in performance, because they have more components. This problem is remarkable in small pixel pitch. The newly developed 3.4 µm pitch GS CIS solves this problem by using multiple accumulation shutter technology and the gentle slope light guide structure. As a result, the developed GS pixel achieves 1.8 e− temporal noise and 16,200 e− full well capacity with charge domain memory in 120 fps operation. The sensitivity and parasitic light sensitivity are 28,000 e−/lx·s and −89 dB, respectively. Moreover, the incident light angle dependence of sensitivity and parasitic light sensitivity are improved by the gentle slope light guide structure.