Edge-lit system for liquid crystal displays (versions)

FIELD: electricity.

SUBSTANCE: invention is related to edge-lit systems. The edge-lit system comprises an emission source in the forms of at least one light-emitting diode; the lower mirror with reflective coating; the upper reflective and diffusion film placed above the lower mirror and edge mirrors at four sides thus forming an air-filled waveguide together with the lower mirror and the upper reflective and diffusion film. The upper reflective diffusion plate is made of material with volume-diffuse scattering and reflective coating applied to its lower side; it has a number of transparent or partially transparent areas.

EFFECT: improving brightness and uniformity of lighting.

4 cl, 6 dwg

 

The invention relates to backlight liquid crystal displays, in particular to the systems side of the backlight for increased brightness and uniformity of illumination.

Currently, there are various designs of systems backlighting for LCD displays. First of all, we can distinguish two basic types of illumination direct illumination and side. When using direct illumination radiation sources are located under the LCD panel and directly illuminate the display. Uniform illumination is achieved through the use of various optical elements, such as wide-angle lenses above sources, allowing to obtain the desired radiation indicatrix, various optical film etc. of the System with a direct backlight to achieve high uniformity of illumination of the LCD display, however, have the serious disadvantage of a greater thickness of the system. In this regard, are more promising system with side-lit LCD displays. In the lights of this type, the radiation sources are located at the side of the display and the radiation from them is propagated through the waveguide under the LCD panel, gradually and uniformly illuminating the display. The waveguide is typically used plate called waveguide plate made of optical material, and to gradual the frame, uniform output radiation from it, on the plate are exposed to different output elements. The uniformity of the output is achieved by the appropriate geometry and location of output elements, and the geometry of the waveguide plate.

All known system with side lights are quite effective, but have a number of significant disadvantages associated with the use of the waveguide plate.

The disadvantages of the systems with the waveguide plate may include such as: the effective complexity of the input radiation through the end face of the waveguide plate, and the difficulty rises further when attempting to reduce the thickness of the illumination system, the relative fragility of the thin waveguide plate, which does not significantly reduce its thickness, and hence the thickness of the entire system. Also the disadvantages of the waveguide plate are its great weight and value.

In this regard, recently appeared system based on the side lights, but not using the waveguide plate. As the waveguide used in such systems the air enclosed between the mirrored or partially mirrored elements. This waveguide was named air waveguide. It eliminates most of the disadvantages of the scheme with volnovod the second plate, but at the same time creates other problems that must be overcome.

The most difficult is the problem of uniform output radiation from the air waveguide. In known systems, LCD backlight use various methods of radiation output from the waveguide, such as: application of the scattering dots on the bottom or the top of the waveguide, using a special prismatic, conical or lens structures affixed to the bottom or the top of the waveguide, the application of bar structures on the bottom or the top of the waveguide and so on. All these methods are based on the principle of violation of the law of total internal reflection at the site of contact of the waveguide and any applied or glued structure that allows us to derive the radiation from the waveguide. However, in case of refusal from the use of the waveguide plate, these methods cannot be applied due to the lack of physical waveguide. The output radiation can be arranged at the expense of introduction of system of waveguide original design, made in the form of a mirrored top film with variable indices as reflection and transmission by its area (see, for example, patent application U.S. No. US 2010/0238686) [1]. Indicators of reflection and transmission vary along the length and width of the film as the distance from the source of irradiation is Oia. The main problem in the backlight systems is the heterogeneity of the display brightness. To solve this problem, the indices of refraction and reflection of the upper film are changed sufficiently complex law (see Fig.1). The most significant drawback of this scheme is the need for continuous smooth change of parameters of reflection and transmission to ensure uniform illumination. Practically it is only possible to produce a film with zonal data for reflection and transmission, which leads to a great imbalance in the backlight of the LCD display. The output radiation can be arranged using an improved collimating system and the top, forming the waveguide film with perforation (see patent application U.S. No. 2011/0032449) [2]. The film may be perforated with holes of different shapes and different laws of distribution of these holes. Assume that with this method the output collimating system should provide a small beam divergence at the entrance to the air waveguide (not more than 30 degrees), and perforated upper film will allow portions to output radiation from the air waveguide on the LCD display (see Fig.2). This radiation appears at quite large angles of inclination relative to the normal display. This lighting display that work well which opens only when the radiation incidence angles, close to normal, is extremely inefficient. Therefore, these output requires additional mixing radiation, which is another additional waveguide is located directly above the first (see Fig.3). The described system can be considered as a prototype of the claimed invention. As disadvantages of this system it should be noted that the system with two air waveguides can not fully provide the necessary angular radiance emerging from the illumination system radiation due to the lack of dispersion in the air of the upper waveguide and, consequently, insufficient mixing of different angular modes of the emergent radiation. In addition, the system, consisting of a large number of elements and including a collimator, is relatively expensive and difficult to align.

The problem to which the invention is directed, is to develop a system LCD backlight based on the air waveguide, providing a high uniformity of the backlight of the LCD screen and the required angular indicatrix radiation emerging from the illumination system. This system should be applicable for LCD displays with large screens, but have reduced dimensions, polysensuality and ease of alignment.

The technical result is achieved due to the design of the illumination system (two variants), liquid crystal displays, providing high uniformity, brightness and the desired angular indicator lights. While the implementation of the illumination system provides for either mixing of radiation and the output from the air waveguide using only the mirror-diffusive film, or the use of additional light guide film, which can significantly reduce the accuracy requirements of manufacturing the mirror-diffuse film.

In Option 1, the backlight of the LCD display contains:

the radiation source in the form of at least one led;

the lower mirror with a mirror coating.

- top mirror-diffusion film located above the bottom mirror and made in the form of a plate, made of a material with three-dimensional diffuse scattering, and on the lower side of the plate caused mirrored coating having a number of transparent areas;

- side mirrors on all four sides and forming together with the lower mirror and the upper mirror-diffusion film air waveguide.

In Option 2, the backlight of the LCD display contains:

the radiation source in the form of at least one led;

the lower mirror with a mirror coating.

p> - top mirror-diffusion film located above the bottom mirror and made in the form of a plate, made of a material with three-dimensional diffuse scattering, and on the lower side of the plate caused mirrored coating having a number of transparent areas;

- side mirrors on all four sides and forming together with the lower mirror and the upper mirror-diffusion film air waveguide;

- light guide film located directly above the bottom mirror and configured to transfer a portion of the radiation from the source to the opposite end of the air duct.

It should be noted that the sign of "transparent" in terms of areas mirrored coating should be understood as opposed to a sign of "opaque", i.e. includes both absolute transparency and partial transparency.

For a better understanding of the invention the following are examples of implementation of the invention with reference to graphic materials.

Fig.1 - System with a variable index of refraction and reflection, known from the prior art.

Fig.2 - System prototype with collimating system known from the prior art.

Fig.3 - System prototype with collimating system and the additional waveguide, known from the prior art.

Fig.4 - System podsi the key in the inventive embodiment 1.

Fig.5 - lighting System in the present embodiment 2;

Fig.6 - Design of the light guide film for the illumination system claimed in option 2.

Presented on Fig.4 diagram of the inventive system backlight LCD display option 1 provides that the radiation from the led light source 11 propagates in the air waveguide formed by the lower mirror 13, the side mirrors 14 and the top mirror-diffusive film 12. Mirror-diffusive film is a thin plate of optical material with diffuse scattering, is used as the substrate on the lower surface of which is applied mirror coating 15, with a transparent hole 16. The number of transparent holes may vary in specific constructions, but in any case, it is preferable to have multiple (>1) holes for multiple light beams. Thus, spreading in the air waveguide, the radiation from the source as it propagates in the waveguide portion is displayed through the transparent areas over the entire area of the waveguide. Then displayed thus radiation, undergoes additional diffuse scattering in the material of the mirror-diffuse film and after exiting the illumination system illuminates the liquid crystal display (not illustrated). P is such a combination of mirror coatings with a number of transparent areas and a substrate of diffuse material allows to obtain good uniformity, and high brightness of the illumination system.

Presented on Fig.5 diagram of the inventive system backlight LCD display option 2 provides that the radiation from the led light sources 110 extends in the air waveguide formed by the lower mirror 130, the side mirrors 140 and the top mirror-diffusive film 120. Mirror-diffusive film is a plate of optical material with diffuse scattering, is used as the substrate on the lower surface of which is applied mirror coating 150, containing a number of transparent areas 160. Some of the radiation from sources in the distribution process goes on located below the light guide plate 170. This plate has a receiving part 171 (Fig.6)made in the form of prismatic structures. Radiation getting into the light guide film through the receiving part, then apply it as the waveguide to the opposite end of the plate, which is output part 172. Output part 172 is also made in the form of prismatic structures through which the radiation is output from the light guide plate. This light guide plate can effectively transfer a portion of the radiation from the source to the opposite end of the air waveguide and significantly reduces the requirements to the form and arrangement of the transparent areas on the LCD is the super-diffusion film. Thus, spreading in the air waveguide, the radiation from the source as it propagates in the waveguide portion is displayed through the transparent areas over the entire area of the waveguide. Then displayed thus the radiation undergoes additional diffuse scattering in the material of the mirror-diffuse film and after exiting the illumination system illuminates the liquid crystal display (not illustrated). This combination of mirror coatings with a number of transparent areas and a substrate of diffuse material allows to obtain good uniformity and high brightness of the illumination system.

Both variants are described as examples of implementations of the invention may find application in the construction of devices with LCD displays, characterized by the reduced thickness and high uniform illumination brightness.

1. The system side of the LCD backlight, comprising:
the radiation source in the form of at least one led,
the bottom mirror with a mirror coating
the top mirror-diffusion plate and
the side mirrors on all four sides and forming together with the lower mirror and the upper mirror-diffusion plate air waveguide,
thus the top mirror-diffusion plate in the being of a material with three-dimensional diffuse scattering coated on its lower side a mirror coating which has a number of transparent or partially transparent areas.

2. The system under item 1, in which the aforementioned transparent areas in the mirrored coating mentioned mirror-diffusion plate is made in the form of round holes.

3. The system side of the LCD backlight, comprising:
the radiation source in the form of at least one led,
the bottom mirror with a mirror coating
the top mirror-diffusion plate,
the side mirrors on all four sides and forming together with the lower mirror and the upper mirror-diffusion plate air waveguide; and
the light guide plate directly above the bottom mirror,
thus the top mirror-diffuse plate made of a material with three-dimensional diffuse scattering coated on its bottom side mirror coating, which has a number of transparent or partially transparent areas,
the light guide plate comprises an inlet, waveguide and output units and configured to transfer a portion of the radiation from the radiation source on the opposite end of the air duct.

4. The system under item 1, in which the aforementioned transparent areas in the mirrored coating mentioned mirror-diffusion plate is made in the form of round holes.



 

Same patents:

FIELD: electricity.

SUBSTANCE: integrated vision and display system contains a layer generating display image; image detector is designed for visualisation of infrared radiation in the narrow range of angles in regard to display surface normal and it includes reflection of one or more objects at the display surface or close to it; radiator of the vision system is designed to radiate infrared radiation for the purpose of objects lighting; light waveguide passes visible and infrared radiation and has the opposite upper and/or lower surfaces designed to receive infrared radiation from the vision system radiator, to guide infrared radiation by TIR from the upper and lower surfaces and projection of infrared radiation to an object outside limits of the narrow range of angles in regard to display surface normal.

EFFECT: improving functionality and small size of the device.

14 cl, 14 dwg

FIELD: physics, optics.

SUBSTANCE: system for scanning collimated light comprises an optical waveguide, a system for inputting light into the first end of the optical waveguide and a controller for controlling position along the first end of the optical waveguide. The optical waveguide comprises a first end, a second end opposite the first end, a viewing surface which continues at least part between the first end and the second end, a back surface opposite the viewing surface, and an end reflector located at the second end of the optical waveguide. The end reflector comprises one or more polyhedral lens structures and a diffraction grating.

EFFECT: high efficiency of scanning collimated light.

13 cl, 16 dwg

FIELD: electricity.

SUBSTANCE: to obtain infrared radiation an electrical signal is sent to the input of the preemphases unit. The preemphases unit changes the signal form by taking the 8-th root of it. The changed signal is then sent to the input of the infrared radiation source.

EFFECT: simplification and acceleration of signal processing.

3 dwg

FIELD: electricity.

SUBSTANCE: group of inventions relates to lighting engineering. Backlight lighting device (24) is equipped with backlight base (22) with mounted LED unit (32) and a light-conducting plate (20), which lateral surfaces are light-receiving surfaces (20a). The LED unit (32) is faced to light-receiving surfaces (20a) of the light-conducting plate (20). The backlight base (22) has guide pins (40) protruding from the base plate surface (22a), at that the light-conducting plate (20) has concave connecting sections (38) at positions faced to the guide pins (40), while the guide pins (40) are coupled to the connecting sections (38). Lateral surface of each guide pin (40) is equipped with a through hole (40a), which passes through the above lateral surface.

EFFECT: prevention or exclusion of uneven brightness of the light emitted through the light-conducting plate.

9 cl, 12 dwg

FIELD: electricity.

SUBSTANCE: multielement terahertz radiation generator includes test sample, femtosecond laser, multielement emitter where element emitter is made in the form of crystal semiconductor with sputtered metal mask forming sharp laser illumination gradient for crystal semiconductor layer. On the boundary of illuminated and shaded parts of semiconductor layer, a sharp gradient of photoexcited charge carrier concentration is formed parallel to the semiconductor surface. In addition the device includes elliptical mirror forming a focused terahertz radiation beam, while multielement emitter includes a raster of cylindrical microlenses distributing laser radiation between element emitters and illuminating only those semiconductor layer areas involved in terahertz radiation generation. The metal mask is made in the form of flat metal stripes.

EFFECT: increased power of terahertz radiation, possible application of small test samples.

3 cl, 2 dwg

FIELD: physics.

SUBSTANCE: passive optical shutter has a reflecting metal film on a substrate, placed in the intermediate real image plane of the optical system of a radiation detector. The film has an underlayer of a thermal decomposing chemical compound with emission of gases.

EFFECT: high shutter speed, low radiation intensity threshold of actuation of the shutter.

3 cl, 5 dwg

FIELD: technological processes.

SUBSTANCE: invention relates to lighting engineering. The illumination system comprises a light-emitting part (1), having light sources configured to emit light beams at different dominant wavelengths, and an image-forming optical system (3), having microlenses (3a) configured to focus the light beams emitted by the light-emitting part (1). The illumination system is configured to illuminate a liquid crystal panel with light beams passing through the image-forming optical system (3). The liquid crystal panel has pixels which are spaced apart by a predetermined spacing and each of which has display elements corresponding to each separate colour, and under the condition that the spacing of the pixels is denoted by P, and the image-forming optical system has a zoom factor (1/n), the light sources are spaced apart by a spacing P1, given as P1=n × P, and the microlenses are spaced apart by a spacing P2, given as P2=(n/(n+1)) × P.

EFFECT: high quality of display by suppressing non-uniformity of brightness and colour in the display screen.

32 cl, 16 dwg

FIELD: physics, optics.

SUBSTANCE: invention relates to optical engineering. The apparatus for modulating monochromatic optical radiation comprises an optically transparent medium in which are mounted a splitter for splitting monochromatic optical radiation into a first and a second propagation channel, a reflecting element in the second channel, a coherent summation portion for forming modulated monochromatic optical radiation. The splitter used for splitting monochromatic optical radiation into a first channel and a second channel is a splitting cube consisting of two identical triangular prisms joined by their large faces. The first channel is equipped with its own reflecting element. Each reflecting element is deposited on the corresponding face of the splitting cube on the path of the monochromatic optical radiation in the first and second channels. The splitting cube is mounted such that it can move back and forth outside the interface plane of its prisms, and the angle α between the velocity vector of the back and forth movement and the interface plane of the prisms of the splitting cube is selected from the relationship , where fm is the required modulation frequency of the monochromatic optical radiation, λ0 is the wavelength of monochromatic optical radiation at the input of the splitting cube, υ is the velocity of the splitting cube.

EFFECT: resistance to vibrations and pushing, capacity to operate in all spatial orientations.

2 dwg

FIELD: electricity.

SUBSTANCE: invention relates to the field of lighting equipment. A highlighting unit 12 consists of a LED 17, a chassis 14 including a base plate 14a mounted at the side opposite to the side of the light output in regard to the LED 17, at that the chassis 14 contains the LED 17 and the first reflective sheet 22 that reflects light. The first reflective sheet 22 includes a four-sided base 24 running along the base plate 14a and two elevated portions 25 and 26, each of these portions is elevated from each of two adjacent sides of the base 24 in direction of the light output. There is a junction J between two adjacent side edges 25a and 26b of the elevated portions 25 and 26. In the highlighting unit 12 the side edge 25a of the first elevated portion 25 out of the two elevated portions 25 and 26 has a face piece 28 faced to the side edge 26a of the elevated portion 26 in the same direction in which the first elevated part 25 is elevated from the base 24 outside towards axis Y, and the first elevated part 25 and the face piece 28 are extruded towards direction of the light output.

EFFECT: elimination of uneven brightness.

22 cl, 29 dwg

FIELD: electricity.

SUBSTANCE: display device contains ambient light system (100) to emit ambient light (106) to the wall (107) behind display device (104). Ambient light system includes at least one source (101) of light located in the central part of display device (104) rear side and at least one reflector (102) located at display device (104) rear side. At least one reflector (102) is located at the periphery of display device (104) rear side so that when display device (104) is located close to the wall (107) the light emitted by at least one source of light is reflected by reflector (102) towards the wall (107) in such way that reflected light (106) at least partially encloses the observed area of display device (104) at the periphery.

EFFECT: improving efficiency.

13 cl, 7 dwg

FIELD: mechanical engineering.

SUBSTANCE: device has signal form generator, power amplifier and electromechanical block, including first fixed magnetic system and first coil of current-conductive wire, additionally included are integrator and corrector of amplitude-frequency characteristic of electromechanical block, and block also has second fixed magnetic system and second coil of current-conducting wire, rigidly and coaxially connected to first coil. Connection of first and second coils with fixed base is made in form of soft suspension with possible movement of first and second coils, forming a moving part of modulator, relatively to fixed magnetic systems, while output of said signal shape generator is connected to direct input of integrator, inverse input of which is connected to speed sensor of moving portion of modulator, output of integrator is connected to input of corrector, to output of which input of said power amplifier is connected.

EFFECT: higher precision.

3 cl, 8 dwg

FIELD: conversion of optical radiation by using nanotechnology.

SUBSTANCE: transparent nano-particles having volume of 10-15 cm3 are illuminated by white light. Nano-particles are activated by impurity atom with concentration of 1020-1021cm-3 and are strengthened in form of monolayer onto transparent substrate. Nano-particles are made of glass and are glued to substrate by means of optically transparent glue. Substrate can be made flexible.

EFFECT: high brightness of image.

4 cl, 1 dwg

FIELD: optical instrument engineering.

SUBSTANCE: modulator has non-monochromatic radiation source, polarizer, first crystal, first analyzer, and second crystal, second analyzer which units are connected together in series by optical coupling. Modulator also has control electric field generator connected with second crystal. Optical axes of first and second crystals are perpendicular to direction of radiation and are parallel to each other. Axes of transmission of polarizer and analyzers are parallel to each other and are disposed at angle of 45o to optical axes of crystals.

EFFECT: widened spectral range.

3 dwg

FIELD: engineering of displays.

SUBSTANCE: to decrease number of external outputs of screen in liquid-crystalline display, containing two dielectric plates with transparent current-guiding electrodes applied on them, each electrode of one plate is connected to selected electrode of another plate by electric-conductive contact, while each pair of electrodes is let out onto controlling contact zone, and electrodes, forming image elements of information field of screen, on each plate are positioned at angle φ similar relatively to external sides of plates, while angle φ satisfies following condition: 10°≤φ≤85°.

EFFECT: decreased constructive requirements for display.

4 cl, 4 dwg, 1 tbl

FIELD: optical engineering.

SUBSTANCE: device has optically connected single-frequency continuous effect laser, photometric wedge, electro-optical polarization light modulator, first inclined semi-transparent reflector, second inclined semi-transparent reflector and heterodyne photo-receiving device, and also second inclined reflector in optical branch of heterodyne channel, high-frequency generator, connected electrically to electro-optical polarization modulator, direct current source, connected to electrodes of two-electrode vessel with anisotropic substance, and spectrum analyzer, connected to output of heterodyne photo-receiving device.

EFFECT: possible detection of "red shift" resonance effect of electromagnetic waves in anisotropic environments.

1 dwg

FIELD: electro-optical engineering.

SUBSTANCE: fiber-optic sensor system can be used in physical value fiber-optic converters providing interference reading out of measured signal. Fiber-optic sensor system has optical radiation laser detector, interferometer sensor, fiber-optic splitter, photodetector and electric signal amplifier. Interferometer sensor is equipped with sensitive membrane. Fiber-optic splitter is made of single-mode optical fibers. Connection between fiber-optic splitter and interferometer sensor is based upon the following calculation: l=0,125λn±0,075λ, where l is distance from edge of optical fiber of second input of fiber-optic splitter to light-reflecting surface of sensor's membrane (mcm); λ is optical radiation wavelength, mcm; n is odd number within [1001-3001] interval.

EFFECT: simplified design; compactness; widened sensitivity frequency range.

4 cl, 1 tbl, 3 dwg

FIELD: electro-optics.

SUBSTANCE: method can be used in optical filter constructions intended for processing of optical radiation under conditions of slow or single-time changes in processed signal, which changes are caused by non-controlled influence of environment. Optical signal is applied to entrance face of photo-refractive crystal where phase diffraction grating is formed by means of use of photo-refractive effect. Reflecting-type phase diffraction grating is formed. For the purpose the optical signal with duration to exceed characteristic time of phase diffraction grating formation, is applied close to normal line through entrance face of photo-refractive crystal of (100) or (111) cut onto its output face which is formed at angle of 10°to entrance face. Part of entrance signal, reflected by phase diffraction grating, is used as output signal. To apply optical signal to entrance face of photo-refractive crystal, it has to be transformed into quazi-flat wave which wave is later linearly polarized.

EFFECT: power independence of processing of optical signal.

2 cl, 2 dwg

FIELD: measuring equipment.

SUBSTANCE: optical heat transformer includes base of body with optical unit positioned therein, transformer of heat flow and consumer of heat flow in form of thermal carrier. Optical unit consists of optical heat source and reflectors of coherent heat flows and concentrator - generator of coherent heat flow in form of two collecting mirrors and a lens, positioned on different sides of source, with possible redirection of coherent heat flow for interaction with transformer of heat flow with following transfer of heat flow.

EFFECT: decreased energy costs.

1 dwg

FIELD: measuring technique.

SUBSTANCE: electro chromic device has first substrate, which has at least one polymer surface, ground primer coat onto polymer surface, first electro-conducting transparent coating onto ground primer coat. Ground primer coat engages first electro-conducting coating with polymer surface of first substrate. Device also has second substrate disposed at some distance from first substrate to form chamber between them. It has as well the second electro-conducting transparent coating onto surface of second substrate applied in such a way that first coating is disposed in opposition to second one. At least one of two substrates has to be transparent. Device also has electrochromic medium disposed in chamber, being capable of having reduced coefficient of light transmission after electric energy is applied to conducting coatings. Electrochromic medium and ground primer coat are compatible.

EFFECT: simplified process of manufacture; cracking resistance.

44 cl, 1 dwg

FIELD: laser and fiber optics.

SUBSTANCE: in accordance to invention, optical wave guide is heated up during recording of Bragg grating up to temperature, which depends on material of optical wave guide, and which is selected to be at least 100°C, but not more than temperature of softening of optical wave guide material, and selected temperature is maintained during time required for recording the Bragg grating.

EFFECT: increased thermal stability of recorded Bragg gratings.

2 cl, 3 dwg

Up!