This paper presents a novel high-sensitivity and wide dynamic range complementary metal oxide semiconductor (CMOS) active pixel sensor (APS) with an overlapping control gate. The proposed APS has a high-sensitivity gate/bodytied (GBT) photodetector with an overlapping control gate that makes it possible to control the sensitivity of the proposed APS. The floating gate of the GBT photodetector is connected to the n-well and the overlapping control gate is placed on top of the floating gate for varying the sensitivity of the proposed APS. Dynamic range of the proposed APS is significantly increased due to the output voltage feedback structure. Maximum sensitivity of the proposed APS is 50 V/lux•s in the low illumination range and dynamic range is greater than 110 dB. The proposed sensor has been fabricated by using 2-poly 4-metal 0.35 μm standard CMOS process and its characteristics have been evaluated.

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In this paper, we propose a block-based low-power complementary metal oxide semiconductor (CMOS) image sensor (CIS) with a simple pixel structure for power efficiency. This method, which uses an additional computation circuit, makes it possible to reduce the power consumption of the pixel array. In addition, the computation circuit for a block-based CIS is very flexible for various types of pixel structures. The proposed CIS was designed and fabricated using a standard CMOS 0.18 µm process, and the performance of the fabricated chip was evaluated. From a resultant image, the proposed block-based CIS can calculate a differing contrast in the block and control the operating voltage of the unit blocks. Finally, we confirmed that the power consumption in the proposed CIS with a simple pixel structure can be reduced.

In this paper, we propose a complementary metal oxide semiconductor (CMOS) binary image sensor with a gate/body-tied (GBT) PMOSFET-type photodetector for high-speed operation. The GBT photodetector of an active pixel sensor (APS) consists of a floating gate (n + -polysilicon) tied to the body (n-well) of the PMOSFET. The p-n junction photodiode that is used in a conventional APS has a good dynamic range but low photosensitivity. On the other hand, a high-gain GBT photodetector has a high level of photosensitivity but a narrow dynamic range. In addition, the pixel size of the GBT photodetector APS is less than that of the conventional photodiode APS because of its use of a PMOSFET-type photodetector, enabling increased image resolution. A CMOS binary image sensor can be designed with simple circuits, as a complex analog to digital converter (ADC) is not required for binary processing. Because of this feature, the binary image sensor has low power consumption and high speed, with the ability to switch back and forth between a binary mode and an analog mode. The proposed CMOS binary image sensor was simulated and designed using a standard CMOS 0.18 µm process.

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