High SNR fingerprinting structure for LC displays.

The thermoluminescence dosimeter (TLD) has desirable features including low cost, reusability, small size, and relatively low energy dependence. However, the commonly available poly-crystal TLDs (e.g., TLD-100) exhibit high interdetector variability that requires individual calibration for high detection accuracy. To improve individual TLD tracking robustness, we developed an optical fingerprinting method to identify the TLD-100 chips. Seven hundred and fifty-two images were initially captured using a digital microscope camera to build a feature library for both facets of 376 TLD-100 chips. A median intensity thresholding method was used to segment images into foreground and background. The affine transformation was used to register the segmented images to the same position. The fingerprint of each image was calculated from its registered image. All fingerprints were then recorded in an Elasticsearch® search database. The TLD fingerprint match was tested three times when the library was established and repeated once 20months later. All chips were irradiated at 0, 1, 4, and 8Gy on a calibrated clinical MV linac to establish the individual calibration curve. The true positive rate of identifying TLDs based on their optical fingerprints was 100% at initialization of the inventory. After 20months and multiple deployments for characterization, calibration, and dose measurement, the true positive match rate dropped to 99% with zero false-positive matches. The TLDs exhibited high self-consistency in the dose-response test with R2 between 0.988 and 1 with linear regression. The TLD-100 chips surface textures are unique and sufficient to support accurate identification based on the optical fingerprinting. This method provides inexpensive and robust management of the TLDs for individual calibration and dosimetry.

We report on the development of an automated visual inspection system for liquid crystal display (LCD) modules. The system comprises a highly graphical software program, a unique image processing algorithm, a PC interface card for driving different types of LCD modules, and a universal test jig for holding these modules. The system is able to detect faulty or malfunctioning LCD modules with minimum intervention from human operator; allows testing to be carried out for evaluating the display quality such as contrast ratio; is able to create new test databases for new LCD modules; allows permanent storage/backup of test databases for each individual LCD module; and provides a friendly user interface for ease of operation. In addition, the system has the following features: different access levels for different users; an editor for creating software drivers for driving different types of LCD modules; and a graphical help facility.

The evolution of high-NA projection optics design and manufacturing tolerances has been remarkable in recent years. Nevertheless, different instances of identical scanner models can still exhibit unique optical fingerprints which can impart subtle patterning differences for a given mask exposed at nominally identical conditions on different scanners. In some cases, a product can be shown statistically to yield lower when a certain layer is exposed on a particular scanner. Thus it is common to have a certain subset of the total population of tools allowed for certain critical levels, such as gate. Since a single mask is typically shared between the multiple allowed scanners, the optical proximity correction model which is employed in the generation of that mask must represent the average fingerprint of those tools. In practice, CD data may be collected from multiple tools, but more often a single tool is somehow identified as the "golden" tool for the purpose of calibrating the OPC model. Once the mask is generated, however, its printing behavior on multiple scanners can readily be simulated using tool-specific optical models. Such models can be easily generated based upon known optical fingerprint data, such as measured illumination source maps, Jones pupil or Zernike aberration files. This paper investigates the use of tool-specific optical models to elucidate the intersection of design and process variability, which will manifest differently on each scanner, depending upon subtle details of the scanner fingerprint.

Reviewed by: The TVs of Tomorrow: How RCA's Flat-screen Dreams Led to the First LCDs by Benjamin Gross Michael Aaron Dennis (bio) The TVs of Tomorrow: How RCA's Flat-screen Dreams Led to the First LCDs By Benjamin Gross. Chicago: University of Chicago Press, 2019. Pp. 288. We live surrounded by LCD (liquid crystal display) screens; Ben Gross's volume explains the origins of this technology at RCA and how the iconic American firm failed to deliver it to the world. This fascinating story of industrial research, corporate politics, and technological change blends science, technology, and business histories. Gross locates the emergence, efflorescence, and decline of LCD screens at the intersection of three distinct axes—the material logic of LCDs, that is their physical chemistry and often recalcitrant behavior plus the infrastructure for their creation and use; RCA's strategic goals as well as the Sarnoff Laboratory's role in fulfilling them; and the interactions among researchers, their managers, and other RCA divisions. One of the many interesting things readers learn is that the technology dominating our lives received so little support from RCA management. Indeed, they ultimately seemed to value LCD patents more than developing televisions based on this novel display technology. Noteworthy are Gross's discussions about the problem of finding the sources needed to write the history of late twentieth-century corporate R&D. RCA's quest for a follow-up to its color television came in 1951, with legendary founder David Sarnoff's challenge to develop a light amplifier. Efforts ensued to find alternatives to the standard display technology, the CRT (cathode ray tube). RCA pioneered the mass production of these glass bubbles, and it proved hard to break from this anchoring technology. Only after it became clear that CRTs could not be flattened in order to hang from walls and display a quality picture did researchers and management explore and develop alternatives. By 1964, the company's research included liquid crystals and their chemistry; however, as Gross points out, it was never really a large research group. Compared to the well-studied RCA video disc, called a "Manhattan Project," RCA's work on LCDs was a modest effort. Although [End Page 1240] public relations people hyped the research and its potential, this was never a corporate moon shot. Gross rightly highlights the problems in manufacturing the new technology once researchers overcame problems at the bench. Using laboratory notebooks, he delineates how researchers solved the issue of LCDs working at room temperature. Building bridges with RCA's manufacturing divisions became as vital as laboratory research to keep LCD work alive, while management paid more attention to a struggling computer effort and the firm's traditional color television business. Even once the multiple manufacturing problems were solved, the LCDs produced by RCA were for watch displays, not the wall-hanging televisions of the future. The initial secrecy surrounding LCD research demonstrated how highly it was valued, yet RCA soon viewed patents as the real source of value compared to physical products, given the costs and difficulties of profitably manufacturing LCDs in America. Gross's interviews and archival work display the full range of skills required to move lab products to the factory, including individuals with the requisite social skills to borrow resources from other groups. This social aspect of intra-laboratory relations is especially well portrayed. Gross plays with Clayton Christensen's ideas of disruptive innovation in explaining why RCA failed to capitalize on its role as a pioneer in LCD research. He follows LCD researchers at RCA to a new start-up, Optel that fails to take advantage of new LCD chemistry, instead sticking to RCA-based technologies. Small size did not prevent an aversion to change. In his final eloquent chapter, Gross explains that it was only once LCD technology had left RCA that it really grew and developed—as multiple firms, first on the West Coast and then in Japan, invested in significant R&D with specific products in mind. Seiko developed a watch-sized LCD television more advanced than Dick Tracy's, while Sharp demonstrated a fourteen-inch color display in 1988. Ironically, Sharp had approached RCA in 1970 about...

Decision letter: Neural markers of predictive coding under perceptual uncertainty revealed with Hierarchical Frequency Tagging

This paper presents a new 2D-3D switchable driving method for a 3D thin-film transistor liquid crystal display (TFT-LCD) TV. The proposed driving method, which uses a film-type patterned retarder (FPR), can reduce unnecessary power consumption while displaying 2D images. The proposed driving method can change a part of a pixel according to the driving mode; the part is operated as a black matrix in a 3D display mode, whereas in a 2D display mode, the part is operated as a normal pixel. To realize the proposed driving method without increasing the data signal rates, the number of gate driver integrated circuits (ICs), and the bezel size of the panel, a novel pixel structure and an integrated a-Si:H gate driver, which can be implemented in a small size, are developed. The power consumption of the proposed driving method measured at the full white gray level is 67 W in a 47-in full-high-definition (FHD) TFT-LCD TV. This result shows that the power consumption of the proposed driving method decreases by 28% compared with that of the conventional driving method in the 2D display mode.

The Liquid Crystal Display (LCD) module in a high power TEA CO2 laser is easy to couple with electromagnetic interference, so as to affect the normal work of the laser. Therefore, this paper explores the prediction method of Electromagnetic Compatibility (EMC) for the LCD module under transient irradiation in an electromagnetic field. The coupling mechanism of electromagnetic interference received by the LCD module integrated in the laser system was analyzed. On the basis of the coupling of field and line, the field line electromagnetic interference of the LCD module was analyzed and calculated by using the BLT equation in the Taylor form, then, the prediction results were verified by several experimentally. The experimental results show that the interference voltage produced by connect cables coupled with electromagnetic fields on the data lines of LCD display module is 1 V, and exceeds the noise margin of the circuit. So the EMC control measures must be taken to ensure the performance of the LCD module. Moreover, the verification experiments indicate that prediction results for the EMC has correctly reflected the actual EMC performance of LCD module. The method has a guiding significance for prediction and design of EMC of electrical equipment in high-power TEA CO2 lasers.

A ridge and fringe field multi‐domain homeotropic (RFFMH) liquid crystal display was demonstrated. The operating principle of this new display mode is the combination effect of a fringe field and ridge structure to control the tilt direction of the liquid crystal molecules when a voltage is applied. No rubbing treatment is required and, with proper compensation films, the display has very wide viewing angles.

Objective To assess image quality and optimal keV levels of spectral CT virtual monochromatic series in atypical vertebral osteoblastic metastases of lung cancer. Methods Patients with pathologically proven lung cancer who had undergone spectral CT (Discovery CT750 HD, GE) of the chest or abdomen more than twice were analyzed retrospectively. Vertebral osteoblastic metastases were confirmed by follow-up CT examinations, biopsy ,emission CT, PET/CT. The bone lesions were missed due to atypicalappearance or presented with suspicious density at the first exmaination were chosen. A total of twenty two patients with 72 lesions were enrolled. Conventional polychromatic images (140 kVp) and monochromatic images were generated (40 to 140 keV at an interval of 10 keV). The signal to noise ratio(SNR) and contrast to noise ratio (CNR) of the lesions were measured and calculated at all the 12 series images by two radiologists. The two radiologists scored the different series of images independently. Paired sample t test was used to compare SNR and CNR among 40 to 140 keV and 140 kVp images. The inter-observer agreement between the two radiologists was evaluated using Kappa statistics and the difference of different images intrarobserver was compared using Wilcoxon signed rank test. Results The SNR of 140 kVp was 48.03±20.17, and those of 50, 60 70 keV images were 58.52±22.92, 64.07±24.88, 59.54±22.04. SNR of 50, 60, 70 keV images was higher than that of 140 kVp (t values were 13.366,16.278, 18.889,P<0.01), 60 keV images had the highest SNR. The CNR of 140 kVp was 7.64±4.52 and those of 50, 60, 70 and 80 keV images were 7.95±4.99, 8.12±5.08, 8.16±5.05, 7.89±4.81. CNR of 50, 60, 70 and 80 keV images were higher than that of 140 kVp image (t values were 3.519, 5.050, 6.231, 4.413, P<0.01), 60 keV and 70 keV images had the higher CNR than 50 keV and 80 keV. Good interobserver agreement was found for the evaluation of image quality (Kappa =0.864,P<0.05).Moreover, the scores of both the two observes for 60 keV images were higher than 140 kVp images and higher than other monochromatic images. Conclusion Atypical vertebral osteoblastic metastases of lung cancer are more conspicuous in virtual monochromatic images as compared wtih 140 kVp polychromatic images and the optimal energy level was 60 keV, repectively. Key words: Lung neoplasms; Bone neoplasms; Neoplasm metastasis; Tomography, X-ray computed

Using image analysis techniques to enhance TFT-LCD manufacturing yield through timely detection of PI alignment layer defects

An in-plane switching (IPS) liquid crystal display (LCD) containing the zero-azimuth anchoring layers formed only on the electrodes and rubbed polyimide (PI) covered on the other areas was successfully developed. This configuration was realized using photoreactive PI with photo-radical generation units and the mask exposure technique. The maximum transmittance (Tmax) of this LCD was 1.12 times higher than that of a conventional IPS LCD. This was attributed to a large aperture in the voltage-on state because the nematic liquid crystals (NLCs) on the electrodes were barely anchored to the surface, such that the NLCs could be rotated by applying a small in-plane electric field above the electrodes, and by an elastic torque caused by the twisted NLCs between the electrodes. Furthermore, the response times of this LCD were equivalent to those of a conventional IPS LCD because the NLCs between the electrodes quickly recovered to their initial orientation after removing the electric field, and the NLCs on the electrodes followed this movement. This novel LCD is termed a ‘partially zero-azimuth anchoring IPS (PZ-IPS) LCD’, which is the first practical LCD utilizing these weak anchoring characteristics in the history of LCDs.

Response mechanism of a vertical alignment mode driven by fringe-field switching

Background Five-megapixel (MP) displays are recommended as soft copy devices for digital mammogram. An 8-MP liquid crystal display (LCD) (two 4-MP displays within one display) might offer the advantage of being able to view biplane mammography more easily than the dual planes of 5-MP LCDs. Purpose To compare detectability of Breast Imaging Reporting and Data System (BI-RADS) category 3 or higher lesions and reading time on mammography between 5- MP and 8-MP LCDs. Material and Methods The mammograms of 240 breasts of 120 patients including 60 breasts with BI-RADS category 3 or higher lesions and 180 breasts with normal or category 2 lesions were enrolled. All bilateral mammograms were displayed on bifacial 5-MP LCDs or an 8-MP LCD (two 4-MP displays within one display). Six radiologists assessed 240 breasts on each display. The observations were analyzed using receiver operating characteristic (ROC) analysis. A jack-knife method was used for statistical analysis. We employed a paired t-test to determine whether any significant differences existed in the reading time between two different displays. A P value < 0.05 was considered significant. Results The mean areas under the ROC curve obtained using 5-MP and 8-MP LCDs were 0.925 and 0.915, respectively, and there was no significant difference ( P = 0.46). There was also no significant difference in the reading time between two types of displays (57.8 min. vs. 51.5 min, P = 0.39). Conclusion The detectability of BI-RADS category 3 or higher lesions and reading time using an 8-MP LCD were comparable to those using a 5-MP LCD.

Liquid crystal display (LCD) devices are well known to have slow response due to the physical limitations of the liquid crystals. Therefore, fast moving objects in a scene are often seen blurred on an LCD. In order to reduce motion blur, an accurate LCD model and an efficient deblurring algorithm are needed. However, existing LCD models are inadequate to reflect the human eye tracking limitation. Also, the spatial-temporal equivalence in LCD models is widely used but not proven directly in the 2D discrete spatial domain. In this paper, we study the human eye tracking limit by reviewing a number of papers in the cognitive science literature. We provide both theoretical and experimental arguments to support our findings. Also, we prove the spatial-temporal equivalence rigourously and verify the results using real video sequences.

PurposeConfidence intervals play a crucial role in economics and finance, providing a credible range of values for an unknown parameter along with a corresponding level of certainty. Their applications encompass economic forecasting, market research, financial forecasting, econometric analysis, policy analysis, financial reporting, investment decision-making, credit risk assessment and consumer confidence surveys. Signal-to-noise ratio (SNR) finds applications in economics and finance across various domains such as economic forecasting, financial modeling, market analysis and risk assessment. A high SNR indicates a robust and dependable signal, simplifying the process of making well-informed decisions. On the other hand, a low SNR indicates a weak signal that could be obscured by noise, so decision-making procedures need to take this into serious consideration. This research focuses on the development of confidence intervals for functions derived from the SNR and explores their application in the fields of economics and finance.Design/methodology/approachThe construction of the confidence intervals involved the application of various methodologies. For the SNR, confidence intervals were formed using the generalized confidence interval (GCI), large sample and Bayesian approaches. The difference between SNRs was estimated through the GCI, large sample, method of variance estimates recovery (MOVER), parametric bootstrap and Bayesian approaches. Additionally, confidence intervals for the common SNR were constructed using the GCI, adjusted MOVER, computational and Bayesian approaches. The performance of these confidence intervals was assessed using coverage probability and average length, evaluated through Monte Carlo simulation.FindingsThe GCI approach demonstrated superior performance over other approaches in terms of both coverage probability and average length for the SNR and the difference between SNRs. Hence, employing the GCI approach is advised for constructing confidence intervals for these parameters. As for the common SNR, the Bayesian approach exhibited the shortest average length. Consequently, the Bayesian approach is recommended for constructing confidence intervals for the common SNR.Originality/valueThis research presents confidence intervals for functions of the SNR to assess SNR estimation in the fields of economics and finance.