Line Image Sensor Research Articles

Line image sensor-based colony fingerprinting system for rapid pathogenic bacteria identification

The rapid identification of pathogenic bacteria is crucial across various industries, including food or beverage manufacturing. Bacterial microcolony image-based classification has emerged as a promising approach to expedite identification, automate inspections, and reduce costs. However, conventional imaging methods have significant practical limitations, namely low throughput caused by the limited imaging range and slow imaging speed. To address these challenges, we developed an imaging system based on a line image sensor for rapid and wide-field imaging compared to existing colony imaging methods. This system can image a standard Petri dish (92 mm in diameter) completely within 22 s, successfully acquiring bacterial microcolony images. This process yielded a set of discrimination parameters termed as colony fingerprints, which were employed for machine learning. We demonstrated the performance of our system by identifying Staphylococcus aureus in food products using a machine learning model trained on a colony fingerprint dataset of 15 species from 9 genera, including foodborne pathogens. While conventional mass spectrometry-based methods require 24 h of incubation, our colony fingerprinting approach achieved 96% accuracy in just 10 h of incubation. Line image sensor offer high imaging speeds and scalability, allowing for swift and straightforward microbiological testing, eliminating the need for specialized expertise and overcoming the limitations of conventional methods. This innovation marks a transformative shift in industrial applications.

A Swipe-Type Fingerprint Sensor Using Fixed-Displacement Shuttering Scheme

Biometric sensors for wearable devices have a dilemma between the small physical size to fit within the small device and the large sensing area to obtain enough information for reliable recognition. A swipe-type fingerprint sensor is a good candidate that satisfies both of small size and large sensing area. This paper proposes a compact swipe-type fingerprint sensor using a fixed-displacement shuttering scheme to avoid the swiping-speed dependent image distortion. The shutter for a line image sensor is adaptively controlled by the displacement measure unit, which are consist of two lines of pixel array, Soft-XOR circuits and digital control circuits. The displacement of a finger is detected by calculating the pattern matching of two line images, which are separated for fixed distance. The proposed system utilizes optical pixels for high-speed image capturing. The prototype sensor chip was fabricated with $0.25~\mu \text{m}$ standard CMOS process. The sensor chip occupies only 4mm $\times 0.9$ mm and provides 625 dpi up to 25cm/s of swiping speed. Experimental results obtained from the sensor demonstrate that the proposed shuttering method reduced minutiae distribution by factor of 3 over the conventional fixed-time interval shuttering.

Deep Learning-Based Banknote Fitness Classification Using the Reflection Images by a Visible-Light One-Dimensional Line Image Sensor.

In automatic paper currency sorting, fitness classification is a technique that assesses the quality of banknotes to determine whether a banknote is suitable for recirculation or should be replaced. Studies on using visible-light reflection images of banknotes for evaluating their usability have been reported. However, most of them were conducted under the assumption that the denomination and input direction of the banknote are predetermined. In other words, a pre-classification of the type of input banknote is required. To address this problem, we proposed a deep learning-based fitness-classification method that recognizes the fitness level of a banknote regardless of the denomination and input direction of the banknote to the system, using the reflection images of banknotes by visible-light one-dimensional line image sensor and a convolutional neural network (CNN). Experimental results on the banknote image databases of the Korean won (KRW) and the Indian rupee (INR) with three fitness levels, and the Unites States dollar (USD) with two fitness levels, showed that our method gives better classification accuracy than other methods.

Focus on spectroscopy and photonics

Focus on spectroscopy and photonics

Recognizing Banknote Fitness with a Visible Light One Dimensional Line Image Sensor.

In general, dirty banknotes that have creases or soiled surfaces should be replaced by new banknotes, whereas clean banknotes should be recirculated. Therefore, the accurate classification of banknote fitness when sorting paper currency is an important and challenging task. Most previous research has focused on sensors that used visible, infrared, and ultraviolet light. Furthermore, there was little previous research on the fitness classification for Indian paper currency. Therefore, we propose a new method for classifying the fitness of Indian banknotes, with a one-dimensional line image sensor that uses only visible light. The fitness of banknotes is usually determined by various factors such as soiling, creases, and tears, etc. although we just consider banknote soiling in our research. This research is novel in the following four ways: first, there has been little research conducted on fitness classification for the Indian Rupee using visible-light images. Second, the classification is conducted based on the features extracted from the regions of interest (ROIs), which contain little texture. Third, 1-level discrete wavelet transformation (DWT) is used to extract the features for discriminating between fit and unfit banknotes. Fourth, the optimal DWT features that represent the fitness and unfitness of banknotes are selected based on linear regression analysis with ground-truth data measured by densitometer. In addition, the selected features are used as the inputs to a support vector machine (SVM) for the final classification of banknote fitness. Experimental results showed that our method outperforms other methods.

Expansion of Smartwatch Touch Interface from Touchscreen to Around Device Interface Using Infrared Line Image Sensors.

Touchscreen interaction has become a fundamental means of controlling mobile phones and smartwatches. However, the small form factor of a smartwatch limits the available interactive surface area. To overcome this limitation, we propose the expansion of the touch region of the screen to the back of the user’s hand. We developed a touch module for sensing the touched finger position on the back of the hand using infrared (IR) line image sensors, based on the calibrated IR intensity and the maximum intensity region of an IR array. For complete touch-sensing solution, a gyroscope installed in the smartwatch is used to read the wrist gestures. The gyroscope incorporates a dynamic time warping gesture recognition algorithm for eliminating unintended touch inputs during the free motion of the wrist while wearing the smartwatch. The prototype of the developed sensing module was implemented in a commercial smartwatch, and it was confirmed that the sensed positional information of the finger when it was used to touch the back of the hand could be used to control the smartwatch graphical user interface. Our system not only affords a novel experience for smartwatch users, but also provides a basis for developing other useful interfaces.

Single-shot tomography by means of VIPA and spatial phase modulator installed optical interferometer

A VIPA (virtually imaged phased array) installed optical interferometer has been proposed for scanless tomography. Also, a spatial phase modulator and a line-image sensor were installed into the interferometer to realize single-shot measurement by displaying the delay time on a line-image sensor. The correlation peak function was observed on the line-sensor at same time. The envelope of the peak was given by the inverse Fourier transformation of the light source spectrum. The peak position on the image-sensor reflects the sample structure. Furthermore, the correlation peaks are appeared repeatedly along the delay time of the interferometer. The repeated correlation function raise an alignment flexibility of the sample set position, which has been limited in the traditional time-domain interferometry involving the delay time to be zero. The flexibility was experimentally confirmed at 25 mm related to the VIPA coherency. The resolution was experimentally 52.5 μm when the ASE (amplified spontaneous emission) light source of the optical fiber amplifier was used. The single-shot measurement was realized by a line-image sensor of the 30 frames per second. The repeatability of the interfered peak position was 5 μm by the tunable mirror position. The one-dimensional scanless measurement was demonstrated by use of 3-layer glass plates.

Development of Fish Counting Techniques with Stereoscopic Line Image Sensors for Fish Ways at Floodgate

Development of Fish Counting Techniques with Stereoscopic Line Image Sensors for Fish Ways at Floodgate

Line image sensors for spectroscopic applications in the extreme ultraviolet

The spectral range of extreme ultraviolet radiation (XUV or EUV) is an active area of research incorporating many scientific fields such as microscopy, lithography or reflectometry. During the last decade, a lot of effort has been put into transferring many of the known techniques developed at linear accelerators into the laboratory using discharge-produced plasmas (DPPs) or laser-produced plasmas (LPPs) as an alternative light source. In particular, the semiconductor industry is in need of on-site tools in the shorter wavelength range for production and inspection of structured surfaces with nanometer resolution. Here traditional charge coupled device (CCD) image sensors are inapplicable as detectors because of the strong absorption of XUV by matter prohibiting any generation of electron–hole pairs inside a deep lying p–n junction. As a solution, two-dimensional backthinned CCDs are available in the market offering high sensitivity to XUV light. Although for many applications a one-dimensional line scanning image sensor would be sufficient, they are non-existent for XUV. It is only lately that manufacturers have started to adopt the principle of backthinning to CCD line sensors to enhance sensitivity in the long wavelength UV range (>200 nm). Here we show that generally these compact sensors offer good quantum efficiencies in the XUV which make them a candidate for many spectroscopic applications and future industrial inline inspection tools for which costly two-dimensional CCDs are oversized. We have successfully implemented a compact sensor device into a laboratory XUV spectrometer and reflectometer. Our measurements compare the quantum efficiency of a state-of-the-art XUV array CCD to a phosphor-coated line sensor and a new backthinned line sensor. Additionally, we show recorded spectra from a laboratory DPP source to demonstrate the potential of a wide range of applications.

Optoelectronic properties of Pb5CrO8 thin films for application to contact-type line-image sensor

Optical and optoelectronic properties of Pb5CrO8 thin films prepared by an electron-beam evaporation deposition technique are described. The relation between spectral response of Pb5CrO8 thin-film lateral photodetectors and annealing temperature for developing the crystallization of the films is examined. An obtained spectral response for adequate annealing temperature covers an entire visible region. A large ratio of photocurrent and dark current and a fast response characterize the thin-film photodetector. An application to a color contact-type line-image sensor is also discussed to demonstrate the optoelectronic ability of the lateral Pb5CrO8 thin film.

Normal shock wave oscillations in supersonic diffusers

The present paper describes experimental investigations for shock oscillations caused by normal shock wave/turbulent boundary layer interaction in a supersonic diffuser. An array of wall-mounted transducers and especially a line image sensor for the nonintrusive detection of shock displacements were employed to investigate the interactions at low supersonic speeds. The line image sensor was collimated with a conventional schlieren optical system and was a good indicative of capturing the shock oscillating motions in the present configuration. This study shows that the amplitude of the shock motions increases with approaching flow Mach number, and the cause of oscillation of the shock wave can, however, be independent of the Mach number. In addition, the present system employed to determine the shock wave positions and displacements can be effectively applied to a variety of practical problems.

Direct-contact type image sensors using a novel amorphous-silicon photodiode array

A novel type of amorphous-silicon (a-Si:H) photodiode array for direct-contact type (lens-less) line image sensors was developed. A U-shaped top ITO (tin-doped indium oxide) contact and a rectangular a-Si:H window resolves the accumulation of dust from the documents at the steps of the light window. Semi-insulating Al-Si-N and insulating SiN/sub X/ stacked films are successfully applied to the surface protection layer to prevent a charge buildup by friction with documents. >

A217 ラインイメージセンサによる衝撃波の振動の計測

Shock oscillations caused by shock wave / boundary layer interaction in a supersonic nozzle were measured using pressure transducers, schlieren photographs, and Line Image Sensor collimated with schlieren light source. Simultaneous measurements of fluctuating wall pressures and shock images were made to analyze the shock oscillation phenomenon. The shock images oscillating could be successfully captured by Line Image Sensor. The present report aims at adding a knowledge to the previous experiences on shock oscillations, and thereby at better understanding of its mechanism. The present measurements show that the streamwise extent of shock excursion are significantly different from the results of the previous works conducted by the pressure signals alone.

Contact-type line image sensor using Pb_2CrO_5 thin film

A contact-type line image sensor using a semiinsulating Pb(2)CrO(5) thin film deposited on a glass substrate by an electron beam evaporation deposition technique is described. The sensor has a simple structure and a high scanning rate of 1 ms/line. An individual sensor element responds to light modulated at 100-kHz frequency, so a higher scanning rate is expected. A matrix driving method using a simple reading circuit is used to operate a sensor composed of 32 elements at a rate of 8 elements/mm. Some practical results on image reading are demonstrated.

Counting method of fry using a line image sensor.

In the recent field of the fishery, the improvement of the efficiency, automation and labor deduction are needed. A counting task in this field is very important in many cases. In this paper, we present a system which enables a real-time measurement of the number and also the body length of the fry using a line image sensor. Here, we consider a situation that fry are transported from one pond to another pond through a pipe. In our system at one position of the pipe a transparent rectangular channel is mounted. The images of the fry, which run through this rectangular channel, are detected with a line image sensor. The image signals are digitized to binary ones and the contour of the fry are detected. After that, a real-time image analysis is executed with DSP (Digital Signal Processor). Overlapping of two fry images is also analysed. Whenever the fry pass the rectanglar channel, the DSP gives us the number and projection area surrounding length of fry images.

Encoder and strain gauge using laser speckle

Applications of the electronic correlation of speckle pattern to the measurement of surface displacement and strain are described. Basic principles including speckle displacement properties and experimental results using a laser diode and line image sensors are presented.

High-speed CdS0.2Se0.8photoconductor and its application to line-image sensors

The photoelectric properties of CdS 1-x Se x (x = 0.4-1.0) photoconductor-type sensors were measured. The sensors were made by heat-treating an evaporated film under the influence of CdCl 2 vapor. The photocurrent J p is large, and the dark current J d is small; the S/N ratio derived from the J_{p}/J_{d} ratio reaches a value of more than 60 dB. With increasing x , the decay time of the photocurrent decreases, while the rise time increases. By addition of continuous light bias, the rise time is drastically reduced. Furthermore, the decay time is reduced by increasing the applied voltage. These effects are pronounced for a CdS 0.2 Se 0.8 sensor. Using this sensor, we constructed a contact-type line-image sensor (8 bits/mm, 1728 bits), and attained a scanning rate of 1 ms/line and a total time of about 2 s for reading an ISO A4 size document. The reading was performed under an application of 20 V, and an illumination of 7.5-µW/cm2light bias and 15 µW/cm2(∼100 lux) signal light using LED light sources (570 nm).

Shortwave infrared 512 × 2 line sensor for earth resources applications

A buttable 512 × 2 IRCCD line image sensor was developed with Pd 2 Si Schottky-barrier detectors for operation with passive cooling at 120 K in the shortwave infrared (1.1-2.5 µm) band. This monolithic Silicon line imager has 30-µm detectors with 75 percent fill factor and on-chip CCD multiplexers providing one video output for each 512 detector band. The measured performance of the 512 × 2 Pd 2 Si IRCCD line imager operating at a temperature of 120 K and optical integration time of 4 ms includes a signal-to-noise ratio of 241 for irradiance of 7.2 \micro W/cm2at \gamma = 1.65 \micro m, a dynamic range of 5000, and modulation transfer function greater than 60 percent at the Nyquist frequency. Belmish-free imagers with 3 percent nonuniformity under illumination and nonlinearity of 1.25 percent were produced. The total power dissipation of the imager chip is 18 mW.

Application of Line Image Sensors to Intelligent Copier

Application of Line Image Sensors to Intelligent Copier

Application of Line Image Sensor to Intelligent Copier

Application of Line Image Sensor to Intelligent Copier