Continuous Gray Scale Research Articles

Polymer-stabilized V-mode FLCDs and their application to color sequential fullcolor LCDs

Polymer-stabilized FLCDs exhibiting V-shaped switching called PS-V-mode FLCDs are fabricated using newly synthesized photocurable monomers and new FLC materials. These FLCDs show good temperature reliability and high enhancement in the optical throughput, and the reduction of the operating voltage. The device is defect-free and exhibits high contrast ratio 700:1 and further fast response with τ=300–500 μs with continuous grayscale operation. We demonstrate a full color LCD with resolution 254 ppi and 4 in. diagonal using color sequential tecnique.

37.2: Polymer‐Stabilized V‐mode FLCDs and Their Application to Color Sequential Fullcolor LCDs

AbstractPolymer‐stabilized FLCDs exhibiting V‐shaped switching called PS‐V‐mode FLCDs are fabricated using newly synthesized photocurable monomers and new FLC materials. These FLCDs show good temperature reliability and high enhancement in the optical throughput, and the reduction of the operating voltage. The device is defect‐free and exhibits high contrast ratio 700:1 and further fast response with τ = 300 μs ∼ 500 μs with continuous grayscale operation. We demonstrate a full color LCD with resolution 320 ppi and 4inch diagonal using color sequential technique.

Setting White, Black and Gamma on Continuous Tone Grayscale and Color Images using Photoshop

Abstract The contrast range of many digital images needs to be reset before outputting images to various ends. This is especially important when printing to paper because ink absorbs into papers through a capillary action, most in the cheapest papers (such as newspaper) and least in high gloss paper from slick magazines. The capillary phenomenon is known as dot gain In the printing world, since images are redefined as small dots when printing to publications, The result of dot gain is seen most in a loss of details or muddiness in the shadow or the black region of images.

Evaluation of a new ultrasound contrast agent (AI-700) using two-dimensional and three-dimensional imaging during acute ischemia

Background: A new intravenous contrast agent, AI-700, was evaluated to determine whether a bolus injection could be used to detect myocardial perfusion abnormalities during acute ischemia by using 2-dimensional (2D) and 3-dimensional (3D) myocardial contrast echocardiography. Methods: 2D MCE was performed in 14 closed-chest dogs during coronary occlusion by using both continuous and triggered gray scale harmonic imaging and triggered power Doppler imaging. 3D MCE (open-chest) and nuclear perfusion imaging were performed in 10 of the 14 dogs. Postmortem triphenyl tetrazolium chloride (TTC) staining was performed to verify infarction. Results: Thirteen of the 14 dogs had infarct by TTC; all 10 that had nuclear imaging showed a perfusion defect. Of the 13 dogs that had infarction, perfusion defects were detected in all (13 of 13) by gray scale harmonic imaging (sensitivity = 100%), and in 11 of 13 by power Doppler imaging (sensitivity = 85%). All 10 dogs that had nuclear imaging showed perfusion defects by gray scale harmonic imaging (sensitivity = 100%) and 8 of 10 by power Doppler imaging (sensitivity = 80%). The perfusion defect size, derived from 3D imaging (25% ± 12%) correlated well with that from nuclear imaging (24% ± 12%) (y = 0.9x + 3.8, r = 0.96, mean difference = 1.3% ± 2.6%). The perfusion defect mass by 3D (22 ± 14 g) also correlated well with the infarct mass by TTC staining (24 ± 16 g) (y = 0.8x + 2.9, r = 0.89, P <.001, mean difference = −2.8 ± 7.6 g). Conclusion: After a single bolus of AI-700, both 2D and 3D MCE could accurately detect perfusion defects representing the area at risk of infarction during acute ischemia compared with nuclear imaging and predicted the size of infarction as verified by TTC staining. (J Am Soc Echocardiogr 2002;15:686-94.)

Mesogenic Polymer-Stabilized FLCDs Exhibiting Asymmetric and Symmetric (V-Shape) Electrooptic Characteristics

We have succeeded in fabricating a novel FLCD, which exhibits symmetric electrooptic (EO) characteristic called V-shape EO performance, by choosing an appropriate photocuring condition such as applied voltage waveforms and the concentration of photocurable mesogenic monomers. Our mesogenic polymer stabilized (MPS)-V-FLCD shows high contrast ratio owing to zig-zag defect free, continuous grayscale without accompanying switching domains, and good switchability with TFTs due to free from the value of the spontaneous polarization.

Removing Halftone Patterns From Scanned Images

Abstract Using illustrations from published technical articles is part of many lectures and presentation citations, and given the availability of flat bed scanners, should be easy to accomplish. The problem that remains is removing halftone patterns and other periodic noise that result from printing and scanning technology. Practically all magazines and newspapers are printed using a regular halftone pattern that uses an array of dots varied in size to produce the visual illusion of continuous gray scale. Color images are usually printed with three, four or even more such patterns using different colored inks and different pattern orientations. Scanning such images into a computer can introduce a further pattern due to the moire interference between the printed pattern and the spacing of the sensors in the scanner. Such patterns are also characteristic of images obtained from single-chip video cameras because of the color filters present in front of the light sensors on the chip.

Electrooptical Properties of Phase Separated Composite Organic Films of Ferroelectric Liquid Crystals

AbstractA new structure of a light modulating element based on ferroelectric liquid crystal (FLC) is fabricated. It is prepared by the photopolymerization induced phase separation of an initially isotropic solution of FLC and a prepolymer. The element consists of two successive layers parallel to the cell substrates. One layer is the isotropic polymer and the other is the FLC macroscopically aligned by a rubbed alignment layer. A study of electrooptical properties of these FLC elements reveals a continuous gray scale, contrast ratio 100:1 along the cell normal, line addressing times of microseconds in the active mode. Because of their internal structure, they are insensitive to mechanical stress.

Ferroelectric Liquid Crystal Displays with Greyscale

Abstract Having presented a range of powerful FLC display prototypes (among them a 24′ monochrome, a 21′ colour and several different 15′ screens) Canon Inc. in Tokyo is now manufacturing their first commercial FLC product. It is a colour panel with 15′ (38 cm) diagonal with a resolution of 1240 × 1024 picture elements. Each such element (230 pm × 230 pm) can produce 16 different colours due to its subdivision in four parts. When writing a picture a large number of hues can be simulated (32000 or 26000 are stated for the two different versions marketed) by a graphic so-called error diffusion technique. In general this gives a very good rendition of colour images but in certain cases the differently coloured single dots, which can be seen when the observer is very close to the screen, may be disturbing. The origin of this inconvenience is of course the fact that each subpixel only has two states; it cannot produce a continuous grey scale.

Linear electro-optic effect based on flexoelectricity in a cholesteric with sign change of dielectric anisotropy

The linear electro-optic effect in short-pitch cholesterics is based on the linear coupling of the medium with an applied electric field. It has a number of remarkable properties. The electric field causes the optic axis to tilt in a plane parallel to the surfaces of the cell glass plates, giving the same symmetry as the electro-optic effects in the smectic C* phase (surface stabilized ferroelectric liquid crystals and deformed helix mode) and the smectic A* phase (soft mode/electroclinic effect). For shutters and displays this guarantees a very wide viewing angle. The induced tilt is a linear function of the applied field, at least for small fields, which gives a well-controlled continuous grey scale. Furthermore, it is practically independent of temperature. Response times of the order of 100 μs are easily achievable. The most interesting development in this effect would be to extend the linear regime to much larger tilt angles, in particular to 22.5°, where light could be modulated from 100% to zero transmission. In order to do this the perturbation from the quadratic dielectric coupling has to be ruled out or minimized, which requires materials with essentially zero dielectric anisotropy. This has been done, and it has been found that the bare flexoelectric-induced tilt has a surprising range of linearity: The linear response in tilt could be followed up to about 30° after which the high electric field caused breakdown. The response time is typically about 100 μs and below.

光アドレス方式による連続階調・高解像度画像用蓄積型液晶ライトバルブ

光アドレス方式による連続階調・高解像度画像用蓄積型液晶ライトバルブ

Visualization and measurement of concentration and surface range images

Images representing the variation in elemental concentration or some intensity signal proportional to it, are produced by instruments such as the electron and ion microscope. They are customarily presented as “dot” maps in which the density of dots represents the concentration, or if the counting statistics of the signal are adequate, as a continuous tone grey scale image. Range images in which the elevation of a surface is recorded as an array of values which can be displayed as a grey-scale image, are produced by several instruments, including the scanning tunneling microscope, atomic force microscope, interferometric light microscope, and the confocal scanning light microscope. Display of the resulting concentration or elevation data with false color to enhance the visibility of small differences, or with expansion or compression of the vertical scale, or subtraction of a reference surface such as a best-fit plane, are often included. Some instruments offer additional display modes such as line profiles, along with some numerical data, such as the mean, standard deviation and limits of the values.

Electrographic magnetic stylus recording; A high speed non-impact magnetic printing process

An electrographic magnetic printing process is described which uses magnetically attractable and electronically conductive dry toner material deposited directly onto a dielectric layer in response to electronic current flow from one member of an array of magnetically permeable styli. The imaging process is extremely flexible in imaging speed, dot/mm resolution, continuous grey scale, and materials.

A positive-column discharge memory panel without current-limiting resistors for color TV display

The first TV pictures have been achieved on a dc gas-discharge memory panel (green color, 50 × 50 cells, 1-mm pitch). A contrast ratio 90: 1 with continuous gray scale (128 levels) is reported. A time-averaged green area luminance of 360 fL at 0.74 lm/W and a power consumption of 0.53 W/cm2(15 µA/cell) are obtained. The discharge cell has a triode structure, in which a positive-resistance discharge containing a positive column is formed in the cathode-grid-anode space. This permits elimination of the current-limiting resistors. The UV radiation emitted by the Xe + He (47 percent) gas discharge is used to excite the phosphors.

A Device for Measuring Plantar Pressures under the Sole of the Foot

An apparatus is described which gives a rapid and detailed picture of the distribution of pressure under the foot with quantitative information, the pressure distribution being displayed as either a continuous grey scale or a colour contour map on a television monitor. A theoretical analysis of the operating principles is given with evidence for its validity, and the practical problems associated with the more detailed aspects of the equipment are discussed.

An experimental real-time color-TV display with a DC gas-discharge panel

An experimental color-TV picture display is presented on a dc gas-discharge panel which is based on the Burroughs' "self-scan" panel. An array of 127 × 160 dots of three color phosphors were formed on the inner surface of the front glass plate to reproduce color pictures. A thinner center sheet of soda glass with a thickness of 0.25 mm was used so that the phosphors might be excited effectively by the UV radiation generated from the negative glow of the discharge. Based on our vacuum-spectroscopic measurements on various phosphors, Y <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf> :Ce (blue), Zn <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> :Mn (green), and Y <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> :Eu (red) were selected. An excellent color picture was reproduced with a contrast ratio of greater than 30:1 with continuous gray scale.

Formation of synthetic images on a laser-beam-adressed smectic liquid-crystal display

The reproduction and the storage of synthetic images on a smectic liquid-crystal display is described. The ‘write’ is obtained by an infrared laser beam. A spatial modulation of the cell transmission is obtained with a variable alternating voltage applied to the cell. A high-resolution display with high contrast and continuous gray scale was realised.

Electrostatic gray-scale facsimile recording

Gray-scale facsimile recording is achieved by using a special electrode arrangement together with the common electrostatic printing technique. The original optical density of a document is reconstructed on an electrostatic recording medium by varying size and charge density of small charged dots. Thus, the developed charged dots allow a continuous gray scale with optical densities in the limits of 0.05 and 1.6 according to the developing procedure. The resolution of this recording technique may be increased up to 10 dots/mm depending on the geometry of the printing device and the scan mode. A recording speed of several pictures per second of size A4 is possible.

Good quality TV pictures using a gas-discharge panel

Good quality real-time TV pictures were displayed on a matrix gas-discharge panel of 80 columns and 212 rows. The 2.4- in wide × 6.3-in high Burroughs Self-Scan panel displays part of a TV picture, has a peak luminance of 8 fL, and a maximum usable contrast ratio of 40:1. The matrix is addressed one line at a time, using standard TV interlace and a continuous gray scale. Picture quality is comparable to that of a monochrome 25-in CRT and the picture can be readily viewed in a normally lit room. Dominant emission is from the neon gas; panel color is orange-red. Panel luminance and luminous efficiency are low compared to a CRT. The circuitry is more complicated--it must store the video signal and provide a total of 300 V for each display element.

Ultrasonic holography. A promising medical imaging tool.

Initial studies with a prototype ultrasonic holography imager are described. A number of advantages over the B-scan type of ultrasonic imaging appear to be present. The holographic imager shows an entire field of view in real time, exhibits a continuous grey scale image, has a very acceptable line-pair resolution capability, and presents a true focused image. The real time nature of the image produced raises the possibility of a wide range of dynamic studies not possible with conventional ultrasound techniques. Because of the known differences between x-ray and ultrasound interactions with tissues, it is hoped that information complementary to roentgenographic data will be obtainable with this machine.

Images from computers and microfilm plotters

Digital computers are widely used for the processing of information and data of all kinds, including the pictorial information contained in photographs and other graphical representations. Efficient conversion facilities for putting graphical information into the computer and retrieving it in graphical form are therefore much needed. One of the most commonly employed devices for obtaining permanent graphical output from digital computers is the microfilm plotter. Regrettably, present models have no provision for producing images with a continuous gray scale or “halftones.” In this note several programming techniques are described for obtaining halftone pictures from a microfilm plotter under the control of a digital computer. Illustrative examples of several methods are given.