A novel CMOS image sensor using an output voltage feedback with variable dynamic range

We demonstrate a silo-filter (SF) complementary metal-oxide semiconductor (CMOS) image sensor for a chip-scale fluorescence microscope. The extruded pixel design with metal walls between neighboring pixels guides fluorescence emission through the thick absorptive filter to the photodiode of a pixel. Our prototype device achieves 13 μm resolution over a wide field of view (4.8 mm × 4.4 mm). We demonstrate bright-field and fluorescence longitudinal imaging of living cells in a compact, low-cost configuration.

In this study, we used a Complementary Metal Oxide Semiconductor (CMOS) image sensor with immobilizing antibodies on its surface to detect human cytokines, which are activators that mediate intercellular communication including expression and control of immune responses. The CMOS image sensor has many advantages over the Charge Couple Device, including lower power consumption, operation voltage, and cost. The photodiode, a unit pixel component in the CMOS image sensor, receives light from the detection area and generates digital image data. About a million pixels are embedded, and size of each pixel is 3 x 3 μm. The chemiluminescence reaction produces light from the chemical reaction of luminol and hydrogen peroxide. To detect cytokines, antibodies were immobilized on the surface of the CMOS image sensor, and a sandwich immunoassay using an HRP-labeled antibody was performed. An HRP-catalyzed chemiluminescence reaction was measured by each pixel of the CMOS image sensor. Pixels with stronger signals indicated higher cytokine concentrations; thus, we were able to measure human interleukin-5 (IL-5) at femtomolar concentrations.

This paper focuses on the development of Complementary metal-oxide semiconductor (CMOS) image sensor and its applications in aerospace, medical and automotive fields. Firstly, the representative events in history and the contributions of some companies to CMOS image sensor are described. Subsequently, some characteristics of CMOS image sensor are analyzed in the image field involved. In order to evaluate the performance of CMOS image sensor, single even effect and electronic endoscope structures are analyzed and active and passive range finder experiments are carried out. The results show that the imaging based on CMOS sensor can fully meet the requirements of imaging applications in many fields.

The trend in the development and manufacturing of Complementary Metal Oxide Semiconductor (CMOS) image sensors is to miniaturize pixels on the chips and hence to improve their imaging characteristics by providing a higher image resolution. As CMOS technology scales down into submicron regions, the conventional color filters are no longer suitable for generating the desired optical density. The major drawback of the conventional color filters produced from pigment-based positive tone photosensitive compositions, is the heterogeneous dispersion of pigments in photoresist composition resulting in color irregularities due to coarse particles of the pigments. One of the most perspective ways to solve this problem is a replacing the pigment with a dye as a coloring agent and thus, increasing solubility of the latter to obtain a homogeneous colored photoresist composition. In this paper, several novel red dye-containing materials are synthesized and tested to provide a redcolored photosensitive composition. This red-colored photosensitive composition is very promising for application as color filters for CMOS image sensors with high resolution and high level of integration architecture.

Radon (Rn-222) is the main source of radiation exposure to human beings from natural radiation; it is of great significance to study the measuring methods and measuring instruments of radon for natural radiation protection. In recent years, the application of pixel detectors in radiation detection has attracted attention. In this paper, a Commercial Off-the-Shelf Complementary Metal Oxide Semiconductor (COTS CMOS) image sensor which replaces the glass for protection covering in front of the sensors was used to perform a series of measurements to identify alpha particles. During the experiment, the CMOS image sensor was used to record a video during the sampling period, and then use the FFmpeg software to take screenshots of the video by frame. MATLAB was used to count bright spots from the image frames. A measurement chamber was designed to measure radon concentrations, and when the relative humidity was constant, the count of alpha particles by the CMOS image sensor increased along with the increase of the concentration. The experiments verified the feasibility of the low-cost COTS CMOS image sensors to monitor radon.

An Image sensor is converts an image into a digital signal. Both CCD (charged coupled device) and CMOS (complementary metal oxide semiconductor) image sensor technologies are essential for image capturing. CMOS image sensor is still in their early years, still it's set to develop but CCD has number of advantages over CMOS. CCD will give you a assurance for more compact, high image quality and potentially more efficient camera. Both CCD and CMOS Technologies have explained in this paper and also how images are captured as well as types for both types of image sensors have been descried. Some issues such as performance characteristics for better image quality for photography have been covered.

A cost-effective demosaicked image enhancement method for a single chip CMOS (complementary metal oxide semiconductor) image sensor which has on-chip ISP (image signal processor) is introduced. CMOS image sensors are becoming popular, because various circuits can be integrated with it into a single chip. In a single chip CMOS image sensor for handheld devices which requires low power consumption, ISP has to be implemented to small size while maintaining the high performance. Demosaicking and image enhancing are the largest blocks in the ISP, because they need some line memories. In this paper, we propose a new method to minimize the number of line memory. In the proposed method, contrast enhancement is done using the buffered data for demosaicking. The green channel is used instead of luminance. Experimental results indicate that the proposed approach enhances the image quality without additional line memories. The proposed method is implemented on FPGA chip in real time mode, and performed successfully.

Image sensors are the core components of computer, communication, and consumer electronic products. Complementary metal oxide semiconductor (CMOS) image sensors have become the mainstay of image-sensing developments, but are prone to leakage current. In this study, we simulate the CMOS image sensor (CIS) film stacking process by finite element analysis. To elucidate the relationship between the leakage current and stack architecture, we compare the simulated and measured leakage currents in the elements. Based on the analysis results, we further improve the performance by optimizing the architecture of the film stacks or changing the thin-film material. The material parameters are then corrected to improve the accuracy of the simulation results. The simulated and experimental results confirm a positive correlation between measured leakage current and stress. This trend is attributed to the structural defects induced by high stress, which generate leakage. Using this relationship, we can change the structure of the thin-film stack to reduce the leakage current and thereby improve the component life and reliability of the CIS components.

Visible Light Positioning (VLP) is widely recognized as a cost-effective solution for indoor positioning with increasing demand. However, the nonlinearity and highly complex relationship between three-dimensional world coordinate and two-dimensional image coordinate hinders the good performance of image-sensor-based VLP. Therefore, there is a need to develop effective VLP algorithms to locate the positioning terminal using image sensor. Besides, due to the high computational cost of image processing, most existing VLP systems do not achieve satisfactory performance in terms of real-time ability and positioning accuracy, both of which are significant for the performance of indoor positioning system. In addition, the accurate identification of the ID information of each LED (LED-ID) is important for positioning, because if the LED-ID is not recognized well, the positioning can only be achieved in a particular positioning unit and cannot be applied to a large scene with many LEDs. Therefore, an effective image-sensor-based double-light positioning system is proposed in this paper to solve the above problems. We also set up relevant experiments to test the performance of the proposed system, which utilizes the rolling shutter mechanism of the Complementary Metal Oxide Semiconductor (CMOS) image sensor. Machine learning was used to identify the LED-ID for better results. Simulation results show that the proposed double-light positioning system could deliver satisfactory performance in terms of both the real-time ability and the accuracy of positioning. Moreover, the proposed double-light positioning algorithm has low complexity and takes the symmetry problem of angle into consideration, which has never been considered before. Experiments confirmed that the proposed double-light positioning system can provide an accuracy of 3.85 cm with an average computing time of 56.28 ms, making it a promising candidate for future indoor positioning applications.

Star sensor is an essential component of spacecraft attitude control system. Spatial radiation can cause star sensor performance degradation, abnormal work, attitude measurement accuracy and reliability reduction. Many studies have already been dedicated to the radiation effect on Charge-Coupled Device (CCD) and Complementary Metal Oxide Semiconductor (CMOS) image sensors, but fewer studies focus on the radiation effect of star sensor. The innovation of this paper is to study the radiation effects from the device level to the system level. The influence of the degradation of CCD and CMOS image sensor radiation sensitive parameters on the performance parameters of star sensor is studied in this paper. The correlation among the radiation effect of proton, the non-uniformity noise of CCD and CMOS image sensor and the performance parameter of star sensor is analyzed. This paper establishes a foundation for the study of error prediction and correction technology of star sensor on-orbit attitude measurement, and provides some theoretical basis for the design of high performance star sensor.

In this work, we have designed, fabricated and measured the performance of three different active pixel sensor (APS) structures. These APS structures are studied in the context of applications that require low-level light detection systems. The three APS structures studied were—a conventional APS, an APS with a comparator, and an APS with an integrator. A special focus of our study was on both the signal and noise characteristics of each APS structure so the key performance metric of signal-to-noise ratio can be computed and compared. The pixel structures that are introduced in this work can cover a wide range of applications, such as high resolution digital photography using the APS with a comparator, to ultra-sensitive biomedical measurements using the APS with an integrator.

The star tracker is widely used in attitude control systems of spacecraft for attitude measurement. The attitude update rate of a star tracker is important to guarantee the attitude control performance. In this paper, we propose a novel approach to improve the attitude update rate of a star tracker. The electronic Rolling Shutter (RS) imaging mode of the complementary metal-oxide semiconductor (CMOS) image sensor in the star tracker is applied to acquire star images in which the star spots are exposed with row-to-row time offsets, thereby reflecting the rotation of star tracker at different times. The attitude estimation method with a single star spot is developed to realize the multiple attitude updates by a star image, so as to reach a high update rate. The simulation and experiment are performed to verify the proposed approaches. The test results demonstrate that the proposed approach is effective and the attitude update rate of a star tracker is increased significantly.

This paper proposes a novel beehive-shaped reflector for application to light-emitting diode (LED) transceivers for illumination and bi-directional visible light communication (VLC). By using a diffuse propagation model extended to line-of-sight and direct signals, the distribution of illuminance and the path loss of the transceiver are investigated to evaluate the performance of the beehive-shaped reflector. To verify bi-directional communication, a VLC-based image capture system, comprising a complementary metal-oxide semiconductor (CMOS) image sensor and video processor unit, is demonstrated. Real-time images captured by the CMOS camera are successfully transmitted to the monitoring system via a free-space channel at a rate of 115.2 kbps.

Adaptive window thresholding for noise-robust photo detection in OCC

This paper reports on a portable imaging system using a complementary metal oxide semiconductor (CMOS) imager for microfluidic analysis and fluorescence imaging with an organic light emitting diode (OLED). The portable CMOS imager is useful for onsite microfluidic analysis, and the OLED works as a light source for fluorescent observations. The system needs only five elements: a laptop computer, a CMOS imaging device, an optical filter, microfluidic channels, and OLEDs. Using this system, we succeeded in a bead‐based microfluidic assay, capturing the video of the trapping and releasing process. Furthermore, we observed the fluorescent beads and the dye using an OLED as the light source in this system. As a result, we found that (i) submillimeter objects could be in focus with about 1 mm distance from CMOS imaging device surface without a lens; (ii) microfluidic experiments with poly(dimethylsiloxane) channels were possible on the CMOS imager; and (iii) OLED can potentially be used as a light source for this system. We believe that this system is useful for point‐of‐care diagnostic sensing and onsite microfluidic analysis including fluorescence detection. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.