Koninklijke Philips Corporation N.V.

U.S. Philips Corporation

Hendrik Adrianus Van Sprang

Marcus Antonius Verschuuren

Hendrik Johannes Boudewijn Jagt

Thomas Diederich

Berno Hunsche

Henricus G Koopman

Rifat Ata Mustafa Hikmet

Ties Van Bommel

Erik Paul Boonekamp

Eduard Johannes Meijer

Jan De Graaf

Adrianus J De Vaan

Mathias Hubertus Johannes Van Rijswick

Franciscus J Wortel

Gerhard Hebbinghaus

Paulus A Breddels

The present invention relates to a LED module which converts pump light from a LED chip () to light at another wavelength, which is emitted from the module. The conversion takes place in a portion of a luminescent material (). The color purity of the LED module is enhanced by reducing any leakage of pump light using a reflector in combination with an absorber. In one embodiment, the absorber is integrated as one or several thin absorbing layers between the layers of a multi-layer reflection filter (); this may yield an even higher reduction of pump light leakage from the module.

LED module

A semiconductor light emitting diode (, LED), comprising a first and a second electrode () for applying a voltage across an active region () for generation of light, a light emitting surface (), and a plurality of photonic crystals (). Further, at least two photonic crystals () of a first and a second type are adapted to extract light from the active region () and differ from each other with respect to at least one lattice parameter. Each of said at least two photonic crystals () are associated with a respective far field pattern, wherein an arrangement of said plurality of photonic crystals () is provided to arrange said at least two photonic crystals (). In this manner, a far field pattern is created by combining the respective far field patterns associated with each of said at least two photonic crystals ().

Photonic crystal LED

The present invention relates to light sensors for measuring light characteristics. In particular, the present invention relates to a light directionality sensor that is capable of measuring light characteristics such as the light direction, light collimation, and light distribution. According to a first aspect of the present invention there is provided a light directionality sensor comprising a photo-sensor (), comprising a plurality of photo-sensitive elements (), and a plurality of light-absorbing light selecting structures () arranged on the photo-sensor so as to form an array of light-absorbing light selecting structures. In the array of light-absorbing light selecting structures, a succession of at least some of the light-absorbing light selecting structures has varying structural characteristics. The varying structural characteristics is achieved by each individual structure of the succession being formed such that it allows light within a different angle interval with respect to the array to be sensed. Further, according to a second aspect of the invention, there is provided a method for forming a light sensor according to the first aspect of the present invention.

Light directionality sensor

This invention relates to a side-emitting light device comprising two sub-assemblies which are optically bonded together. Each sub-assembly comprises a substrate, at least one light source disposed on the substrate, and a luminescent plate optically bonded with the at least one light source. The light source emits light of a wavelength capable of exciting luminescence light from the luminescent plate. The two sub-assemblies are arranged having the free surface of the luminescent plates facing each other. The side-emitting light device is for instance applicable for light sources comprising naked dies arranged with Thin Film Flip Chip (TFFC) technique or laser diodes.

Side-emitting LED light source for backlighting applications

An electric lamp includes a lamp vessel which is transparent to visible light and accommodates a light source. The lamp vessel is covered with a combination of a light-absorbing medium and an optical interference film having layers of alternately layers of silicon dioxide and layers of a material with a comparatively high refractive index (e.g. ZrO) . The reflection R of the interference film changes from 0.60&#x2266;R&#x2266;0.95 to 0.40&#x2266;R&#x2266;0.65 with a step &#x394;R in the range 0.2&#x2266;&#x394;R&#x2266;0.45, in a wavelength range 0.95&#xd7;&#x3bb;&#x2266;&#x3bb;&#x2266;1.2&#xd7;&#x3bb;. In operation, the electric lamp emits colored light in the transmission mode and has a substantially color-neutral appearance in the off state.

Electric lamp with absorbing and interference media

The electric lamp comprises a lamp vessel ( ) which transmits visible light and which accommodates a light source ( ). The electric lamp comprises a light-absorbing medium ( ). The lamp vessel ( ) is covered with an optical interference film ( ) which comprises layers composed of a first layer of silica and a second layer of a material having a relatively high refractive index which alternate with each other. According to the invention, light from the light source ( ) travels through the light-absorbing medium ( ) before reaching the interference film ( ). Preferably, the light-absorbing layer ( ) is disposed between the lamp vessel ( ) and the interference film ( ). Alternatively, the light-absorbing layer is contained in a wall of the lamp vessel. Preferably, the interference film ( ) reflects substantially in the same wavelength range as that wherein the light-absorbing medium ( ) absorbs, preferably in the range from 570 to 620 nm. Preferably, the electric lamp emits, in operation, colored light but has a color-neutral appearance when the lamp is in the off-state. The light-absorbing layer ( ) preferably predominantly comprises Nd O , CoAl O , Fe O , ZnFe O , ZnO.Fe O or BiVO .

Electric lamp with light-absorbing medium and interference film

Generally known conventional X-ray tubes include a window opening which is covered by an X-ray transparent X-ray window which is usually made of beryllium. A significant absorption of X-rays of comparatively long wavelength, for example of the order of magnitude of from 1 nm to 10 nm, occurs in such windows. According to the invention, a bundle of X-ray conducting capillary tubes (,) is connected to the window opening of the X-ray tube, the other end (,) of the bundle being provided with a very thin X-ray window (,) which seals the interior of the capillary tubes (,), being in vacuum contact with the vacuum space of the X-ray tube, from the environment in a vacuum tight manner.

X-ray irradiation apparatus including an x-ray source provided with a capillary optical system

To obtain a monotonic transmission/voltage characteristic curve in a reflective display having a small twist angle, the polarizer in a cell with crossed polarizer and analyzer is arranged parallel to the dividing line of the directions of orientation (23, 24) determining the twist angle .alpha., the cell being optimized for .alpha. and d..DELTA.n.

Reflective liquid crystal display device with twist angle between

By a suitable choice of a retardation foil with a specific value of .DELTA.n (.lambda.) it is possible to make the transmission/voltage characteristic curves for, for example, red, green and blue light extend parallel in an ECB display. The same type of display can then be used for modulating three colors, with modulation voltages shifted for each color.

Display device having wavelength-dependent birefringence compensation

A liquid crystalline color display cell comprises two transparent, parallel substrate plates, 1, 2 (FIG. 1), a seal 3 and a liquid crystalline cell medium 5 which is present between the plates and the ring. The cell medium contains a dichroic, UV light-absorbing substance. Both substrate plates are provided with electrodes 6, 7 and the substrate plate are provided on the viewing side with a layer 9 of phosphors which emit colored light under the influence of UV light.

Liquid crystalline color display cell having a phosphorescent substrate

A display cell which contains a liquid crystalline compound having a tilted orientation and a tilt angle of 8.degree.-50.degree., in which an orientation layer is used of a cyclo-aliphatic polyether.

Display cell

A liquid crystal display device comprises two supporting plates which are kept spaced apart and the facing surfaces of which comprise a pattern of line electrodes and column electrodes, respectively, which form a matrix of display cells. A mixture of a nematic liquid crystal with a cholesteric addition is present between the supporting plates. The mixture has a positive dielectric anisotropy and a natural pitch p such that the ratio d/p has a value between 0.6 and 0.9. The surfaces comprise an orientation layer to provide a progressive molecular twist .PHI. of the liquid crystal molecules (director) across the layer thickness d of greater than 1.2.pi. and less than 1.7.pi. radians with the director assuming an angle of tilt between 0.degree. and 7.degree. at one surface and an angle of tilt between 5.degree. and 70.degree. at the other surface. Below a field strength E.sub.1 the display cells are in a first stable state and above a field strength E.sub.2 they are in a second state differing optically therefrom. At a field strength E.sub.H between E.sub.1 and E.sub.2 both states may co-exist. Starting from the first state and a field strength E.sub.H across the display cells, the liquid crystal material shows a small energy threshold in such manner that a cell can be switched from the first stable state to the second by means of a pulsatory field having an energy content above the energy threshold. With a pulsatory field having an energy content below the energy threshold, the cell returns to the initial state via a metastable state having a certain relaxation period. When the recurrence frequency with which a picture cell is driven does not exceed the reciprocal value of the relaxation period, more than 2,000 lines can be successively written in this manner within one second.

Growing community of inventors

Eindhoven, Netherlands

Hendrik Adrianus Van Sprang