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1689 results about "High contrast" patented technology

Pixel driving circuit and method of active organic electroluminescent display

InactiveCN101996579ACompensation for brightness non-uniformityAchieve all blackStatic indicating devicesCapacitanceHemt circuits
The invention discloses pixel driving circuit and method of an active organic electroluminescent display. The pixel driving circuit comprises a driving transistor, four switch transistors, a coupling capacitor, a storage capacitor and a light-emitting diode, wherein a drain electrode of the first transistor is connected with a data wire, a grid electrode of the first transistor is connected with a first scanning control wire, and a source electrode of the first transistor is connected with the C end of the coupling capacitor; a drain electrode of the second transistor is connected with source electrodes of the third transistor and the fourth transistor, a grid electrode of the second transistor is connected with the A ends of the coupling capacitor and the storage capacitor and a drain electrode of the third transistor, and a source electrode of the second transistor is connected with a drain electrode of the fifth transistor and the B end of the storage capacitor and is grounded through the organic light-emitting diode; a grid electrode of the third transistor is connected with a second scanning control wire; a drain electrode of the fourth transistor is connected with a power wire, and a grid electrode of the fourth transistor is connected with a light-emitting control wire; and a grid electrode of the fifth transistor is connected with the first scanning control wire, and a source electrode is grounded. The invention can effectively compensate the unevenness of threshold voltages of the transistors and the degradation of a start voltage of the OLED (Organic Light Emitting Diode), ensures that the brightness of an image displayed by the OLED is even and realizes high contrast.
Owner:SOUTH CHINA UNIV OF TECH

Optical element to reshape light with color and brightness uniformity

A light valve such as an active matrix LCD between crossed polarizers, utilizing, for instance, individual transistors to control each "pixel area" of the LCD and storage elements to store video signal data for each pixel, with optically shielded "dead spaces" between pixels to eliminate electric field cross-talk and non-information-bearing light bleed-through, is illuminated with a bright independent light source which creates a video image projected via specialized projection optics onto an internal or external screen without distortions, regardless of the angle of projection onto the screen. Use of heat sinks, IR reflective coatings, heat absorbing optics, optional fluid and a thermistor controlled pixel transistor bias voltage injection servo circuit stabilizes image performance, maintaining accurate color and contrast levels as the LCD changes temperature. In one embodiment of the invention, use of a multi-color LCD with a stepped cavity, producing different thicknesses of LCD for the different wavelengths that pass through it, allows a linear correspondence between the wavelengths passing through the LCD to produce true black, high contrast and CRT-like color rendition. A dichroic mirror arrangement is used to overlap differently colored pixels in the projected image. Use of striped mirrors duplicate pixels, where necessary, eliminating spaces between pixels, creating a continuous image with no apparent stripes or dots. A special venetian-blind type of screen is also disclosed and methods for using the system to view three-dimensional video are also explained.
Owner:DOLGOFF GENE

Vehicle license plate imaging and reading system for day and night

ActiveUS7016518B2Avoid sensor overload headlightAvoid reflected glareOptical rangefindersRoad vehicles traffic controlLicense numberInfrared
This invention provides an infrared illuminator and camera system for imaging of auto vehicle license plates. The system works in ambient light conditions, ranging from bright sunlight, to dim light, to dark, to zero ambient light. It yields high-contrast imaging of the letters and numbers on retro-reflective license plates. The images of the license letter and number combinations can be read manually by a remote operator. They can be converted to text format with optical character recognition computer hardware and software. The text data can then be compared to data files listing license numbers to provide further data about the owner of a licensed vehicle. A decision can be made quickly about whether to allow a vehicle to proceed through a gate, or whether to take other action. The system uses a mono camera that is enhanced for infrared sensitivity and combined with a high power infrared illuminator to maximize range at night, and with shutter speeds set up to capture clear license plate pictures even with fast moving vehicles and even with their headlights on and interfering with human observation of the license plates. Optical filtering to pass infrared in the range of the illuminator and to reduce light outside this range, combines with a lens set up, to avoid vertical smear and sensor overload caused by headlights at night and by highlight reflected glare from the sun in daytime.
Owner:EXTREME CCTV

Active matrix displays having high contrast values

An active matrix display comprises a chiral smectic liquid crystal mixture which has the phase sequence I-N*-SmC*, a spontaneous polarization in the operating temperature range of <40 nC/cm2 and a pitch of >10 mum at at least one temperature in the nematic or cholesteric phase and comprises at least one compound each from at least two of the substance classes (A), (B) and (C) and one or more compounds from substance class (D):(A): compounds comprising two rings which are directly linked to one another and are selected from phenylene-1,4-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl and pyridazine-2,5-diyl with the proviso that at least one of these rings is a nitrogen heterocycle;(B): compounds comprising three rings selected from phenylene-1,4-diyl, two of the rings being directly linked to one another and the third ring being linked to one of the other two rings via an -OC(=O)- or -C(=O)-group, with the proviso that at least one of the three rings is fluorophenylene-1,4-diyl or ortho-difluorophenylene-1,4-diyl;(C): compounds comprising three rings which are directly linked to one another and are selected from phenylene-1,4-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl and pyridazine-2,5-diyl with the proviso that at least one of these rings is a nitrogen heterocycle;(D): compounds comprising mesogenic groups suitable as components of liquid crystal mixtures.
Owner:MERCK PATENT GMBH

Ophthalmic data measurement device, ophthalmic data measurement program, and eye characteristic measurement device

InactiveUS20060170865A1Predict contrast sensitivityRefractometersSkiascopesPupil diameterOphthalmology department
It is possible to estimate optical characteristic according to a pupil diameter in daily life of an examinee, correction data near to the optimal prescription value, eyesight, and sensitivity. A calculation section receives measurement data indicating refractive power distribution of an eye to be examined and pupil data on the eye and calculates lower order and higher order aberrations according to the measurement data and the pupil data (S101 to 105). For example, a pupil edge is detected from the anterior ocular segment image and a pupil diameter is calculated. By using this pupil diameter, lower order and higher order aberrations are calculated. According to the lower order and higher order aberrations obtained, the calculation section performs simulation of a retina image by using high contrast or low contrast target and estimates the eyesight by comparing the result to a template and/or obtains sensitivity (S107). Alternatively, according to the lower order and the higher order aberraations obtained, the calculation section calculates an evaluation parameter indicating the quality of visibility by the eye to be examined such as the Strehl ratio, the phase shift (PTF), and the visibility by comparison of the retina image simulation with the template. According to the evaluation parameter calculated, the calculation section changes the lower order aberration amount so as to calculate appropriate correction data for the eye to be examined (S107). The calculation section outputs data such as the eyesight, sensitivity, correction data, and the simulation result to a memory or a display section (S109).
Owner:KK TOPCON
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