Koninklijke Philips Corporation N.v.

U.S. Philips Corporation

Philips Intellectual Property & Standards Gmbh

Holger Mönch

Carsten Deppe

Peter Lürkens

Gunther Hans Derra

Hans G Ganser

Arnd Ritz

Hanns Ernst Fischer

Xaver Riederer

Gero Heusler

Jens Pollmann-Retsch

Albrecht Kraus

Winston Donald Couwenberg

Wouter Jozef Maes

Edmond Mariette Emile Verstraeten

Johannis Antonie Toonen

Roy Hendrik Zundert

Meng Han

A description is given of a method and a circuit arrangement for operating a high-pressure gas discharge lamp with a lamp current superposed with first current pulses, in particular in a system for the time-sequential production of (primary) colors and possibly white segments, from which an image to be displayed is synthesized, in which, in order to change or correct color and/or brightness properties of the image, the first current pulses are adjusted with regard to their amplitude and/or temporal length and/or temporal position relative to the production of the colors and/or white segments. A description is also given of a projection system comprising such a circuit arrangement.

Method and circuit arrangement for operating a high-pressure gas discharge lamp

A lighting unit is described which has a discharge lamp (), in particular a high pressure or high intensity discharge (HID) lamp or an ultra high performance (UHP) lamp, a lamp driver () and a cooling device (). To reduce mechanical stresses caused by temperature variations in the lamp (), one or more operating parameters of the lamp () are detected. In addition, a control unit is provided for controlling the lamp driver () and/or the cooling device () at least during switching on and/or off of the lighting unit in such a way that there is no excursion from a predetermined range of the at least one operating parameter. By selecting the parameter range suitably, the service life of the lamp may be extended considerably or the power of the lamp may be increased while the service life remains the same.

Lighting unit

The invention relates to a high-pressure discharge lamp which comprises at least a burner () having a symmetrical discharge chamber (), where at least the outer contour of the burner () has an elliptical shape in the region of the discharge chamber (), two electrodes () extending into the discharge chamber () and arranged in mutual opposition on the major axis of symmetry of the discharge chamber (), and a multilayer interference filter () arranged on the outer contour of the burner () in the region of the discharge chamber (), wherein the interference filter () mainly reflects light from at least one wavelength range of the UV light into the space between the two electrodes ().

Ultra-high pressure discharge lamp provided with a multi-layered interference filter on an outer surface of the lamp

The present invention is directed to a wavelength conversion layer () with a matrix layer () comprising embedded rare-earth-ion-doped micro-crystallites () and/or rare-earth-ion-doped amorphous particles, wherein said rare-earth-ion-doped micro crystallites and/or rare-earth-ion-doped amorphous particles are doped with at least one of the lanthanides, and wherein said rare-earth-ion-doped micro-crystallites and/or said doped amorphous particles have a mean diameter dof 10 nm to 500 m&#xfc;m, and wherein the matrix layer, is transparent, whereby the refractive indices of said rare-earth-ion-doped micro-crystallites and/or said rare-earth-ion-doped amorphous particles match the refractive indices of the matrix layer with an index fifference delta n such as: 0&#x3c;_delta n&#x3c;_0.1, for at least one wavelength in the range of 400 nm to 1200 nm.

Wavelength conversion layers with embedded crystallites

A projection system includes an image projection apparatus window and a transparent holographic screen deflecting light from the image projection apparatus into discrete, mutually spaced directions so that an area which is free from images is formed between identical images. Projected, mutually spaced holographic frames of the image is visualized by the holographic screen that includes a film layer which is partially illuminated multiple times at different pick-up angles to the same object of an image, so that the film layer has hologram images of the same object at mutually different pick-up angles. The transparent screen may include many holographic film layers, in which each film layer is illuminated once at different pick-up angles to the same object, so that each film layer has one hologram image of the object at a different pick-up angle.

Projection device for simultaneously generating a plurality of mutually spaced, holographic frames of one and the same image by means of a holographic screen

A projection system having a projection display (), at least one light source (), and a sensor means for sensing and compensating for changes in the luminous flux emitted by the at least one light source () is described. The sensor means comprises in this case at least one sensor arrangement () for sensing components (M) of the light from the light source () that are directed into a region surrounding an entering face of an optical component () of the projection system. It has been found that there is a very good correlation between these components (M) of the light from the light source () and those other components (I) of the light that actually reach the projection display (), which means that by controlling a power supply unit () for the light source () and/or a driver unit () driving the projection display () in a suitable manner it is possible very effectively to suppress fluctuations in brightness that occur as a result of, for example, unstable arc discharges.

Projection system featuring light source luminuous flux sensing and compensation

A projection system for image reproduction includes at least one lamp and sensor for generating a sensor signal for monitoring changes in the luminous flux generated by the lamp and for compensating these changes through a suitable control of the image reproduction. The projection system further includes a device for eliminating substantially periodic interference components from the sensor signal generated by the sensor. These interference components may be generated by an optical component such as a color modulator of the projection system. The projection system provides substantially interference-free compensation of fluctuations in the luminous flux generated by the lamp, for example, owing to an unstable arc discharge. Further, the positioning of the sensor in the projection system may not be critical.

Projection system

The invention relates to a method for operating a discharge lampincluding two electrodesThe method comprises applying to the electrodes an alternating current I. In order to improve the performance of the lamp and to increase the life time of the lamp, it is proposed that the alternating current has a direct current component DC for compensating a temperature difference between the two electrodes. The direct current component is selected more specifically such that a first electrode, which is expected to have a lower temperature than the second electrode, functions as anode for the direct current component, while the second electrode functions as cathode for the direct current component. The invention relates equally to an electronic circuit and to a software program for operating a discharge lamp correspondingly, as well as to a lighting system comprising a discharge lamp and means for operating this discharge lamp correspondingly.

Electrode temperature differential operation of a discharge lamp

A method and a circuit arrangement for the operation of a high-pressure gas discharge lamp (HID [high intensity discharge] lamp or UHP [ultra high performance] lamp) is described, which lamp is particularly suitable for illuminating projection displays with sequential color rendering (for example LCOS or SCR-DMD systems) with a pulsatory lamp current. Artefacts in the color rendering are avoided through the generation of at least one compensation pulse of a given amplitude and a given timing and through superimposition thereof on the lamp current.

A reflector lamp is described which consist essentially of a light source, in particular in the form of a high-pressure gas discharge lamp (HID [high intensity discharge] lamp or UHP [ultra high performance] lamp), as well as a main or secondary reflector (), and a primary reflector () by means of which light from the light source () can be reflected through the light source () onto the main reflector (). The primary reflector () is arranged such that those regions of the main reflector () are obscured which are optically inactivated regions, for example because of a lead-through and/or a fastening device for the lamp, which have no reflection properties, or which have reflection properties that adversely affect the radiation characteristic of the reflector lamp. The reflector lamp is particularly suitable for projection applications because of its high luminous efficacy. Furthermore, a substantially automated and accordingly cost-effective assembly of the lamp is possible.

Reflector lamp with a partially reflective burner

A projection system for image representation includes a display, a lamp, and a sensor for generating a sensor signal for monitoring and compensating changes in the luminous flux provided by the lamp. To achieve a monitoring of the light quantity actually incident on the display, an optical component is arranged in a light path between the lamp and the display. The optical component allows a first light component to pass through and reflects a second light component such that one of the light components is directed at the display and the other light component is directed at the sensor arranged outside the light path. A sensor signal generated in this manner renders it possible to compensate for fluctuations in the luminous flux provided by the lamp through the control of a lamp driver in an effective.

Image projector with intensity-controlled light source

The invention relates to a video projection system comprising at least a light source coupled to a reflector for focusing the light beam, a motor-driven color wheel having a plurality of light-transmitting segments, at least some of said segments being dichroic filters for the colors red, green, and blue, while the speed of rotation of said wheel can be modified by a control, a lens system imaging the focused light beam onto a display, a display system comprising at least a display and a display control, and a projection lens, wherein the video projection system has a video projection mode and a lighting mode, and in addition the color wheel is stationary in the lighting mode and at least one segment of the color wheel can be given a defined position in the beam.

Video projection system

The invention relates to an electronic circuit and a method of supplying energy to a high-pressure gas-discharge lamp H,. The electronic circuit comprises a line-supply input sectionto receive and convert an a.c. voltage from an a.c. line-supply system, an energy storage meansto store the energy put out by the line-supply input sectionand a lamp-current regulating unitthat is supplied with an input voltage Uby the line-supply input sectionvia the energy storage meansand that makes available a lamp current Ifor a high-pressure gas-discharge lamp II,. To make it possible for the energy storage meansto be particularly small, it is proposed that the lamp-current regulating unithave a power section L, D, C, S, A, A, K having a transconductive property. If there is a drop in the input voltage U, this property then automatically produces a reduction in the lamp current Imade available to a high-pressure gas-discharge lamp, H. This ensures a particularly fast adjustment to voltage fluctuations. The invention also relates to a corresponding method.

Electronic circuit and method of supplying energy to a high-pressure gas-discharge lamp

A lens plate integrator includes first and second lens plates which transmit light from a light source on an optical path to a projection plane. Each lens plate includes corresponding first and second groups of lens elements; light from the first group of the second plate is focused on a projection face in the projection plane, while light from the second group of the second plate is focused in front of or behind the projection plane and only partially illuminates the projection face.

Optical projection devices including a lens plate integrator

The invention relates to a measuring circuit for detecting the amount of deposited electrode material on the wall of a lamp vessel of a discharge lamp by measuring the power of infrared radiation within a specific wavelength range, comprising a detector for generating an electrical signal constituting a measure for the power of the infrared light in said specific wave length range. According to the invention the measuring is done in a time lapse starting after a predetermined time interval following the extinguishing of the discharge lamp. An increased accuracy of the measurement is thereby realized.

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Vaals, Netherlands

Holger Mönch