MXPA99006716A - Flat reflector lamp with locally modulated luminance - Google Patents

Abstract

Un proyector plano con descarga dieléctricamente impedida, con geometría de electrodos superficial heterogénea para la modulación local de la densidad lumínica superficial, principalmente para su aplicación en el campo de dispositivos de aviso, por ejemplo, en medios de transporte motorizados.

Description

FLAT PROJECTOR WITH LOCALLY MODULATED SUPERFICIAL LUMINAIRE DENSITY FIELD OF THE INVENTION The invention relates to lamps. There are different types of lamps, which differ according to the criteria of operation principle, size, form of construction, power, etc.

BACKGROUND OF THE INVENTION One of several approaches in the development and selection of types of lamps for certain applications, is the flatness of the generation of light and the homogeneity of the generation of flat light. In some applications, to cite examples, it is about illuminating a surface of a certain extension; to distribute a certain luminous power in a certain surface, to reduce the glare; for reasons of reducing the formation of shadows, to find a lighting solution with light emission distributed as flat as possible; for decorative or design reasons, to make a lamp with as much surface as possible, and still others. These are specific configurations, for example, advertisements illuminated with meander gas discharge lamps or signaling lamps or viewing mirrors with incandescent lamps arranged near the spotlight for the aforementioned aspect of back lighting and flat lighting, combinations of one or more lamps of geometrically large luminescent substances with reflector systems (multiple) for office lighting as an example of the appearance of absence of glare and little formation of shadows, or luminous tables for work with negatives with lamps of vertical luminescent substances or illuminated glass plates from behind with a plurality of incandescent lamps, which diffuse a matt light, for the field of interior architecture and decoration. In many of the above cases, luminescent substance lamps or gas discharge lamps have been used. Incandescent lamps were also used, for example, with reflector systems or systems of a plurality of incandescent lamps. A relatively new type of lamp is the luminescent substance lamp with a dielectrically impeded discharge, which, due to its particular operation, is often carried out as flat projectors. In it, a discharge volume of plates not necessarily flat in the right direction, but laminar and largely flat, for example glass, is formed, the electrode structures being made in one or both glass plates. Due to the distribution of electrodes in a large area and, possibly, due to the use of additional diffusing layers, large-area flat lamps with a very homogeneous light distribution can be achieved.

OBJECTIVES AND ADVANTAGES OF THE INVENTION The present invention starts from the background of the prior art presented, regarding the problem of providing a lamp for applications with a generation of light distributed on a surface, which contributes with new possibilities for the prior art in the which refers to the technical functionality or the aesthetic effect. According to the invention, this objective is achieved by a flat projector with dielectrically impeded discharge, with a heterogeneous flat electrode geometry for the local modulation of the surface light density. With this solution, the invention exploits the particular structure of the flat projector for dielectrically impeded discharges, deliberately not homogenously effecting the distribution of the discharge electrodes on the flat walls of the discharge volume, ie, for example, in two glass plates essentially flat and covering the discharge volume together with a frame. In this way, the invention deviates from the foundation generally prevailing in the prior art in the case of flat lamps or plates to be illuminated from the back in a flat manner and the like, in that it is necessary to pretend a superficial luminous density as homogeneous as possible. This orientation of the invention, which varies from the prior art, is based on the knowledge that there are many applications in which a local modulation according to the application of the surface light density through a correspondingly heterogeneous distribution of the electrodes in the surface of the flat projector. These advantages can be found in the area of better readability of an advertisement or of a sign or a sign, in the area of energy saving through a better orientation of the surface light density to the local lighting requirements, in decorative effects that they can be achieved through the invention and the like. Some examples are illustrated in the present application, and one is indicated in more detail as an example of embodiment; however, the invention relates to lamps and lamps with lamps in accordance with the invention in general. In connection with the invention, an additional measure can be very advantageous, which leads to a preferred embodiment of a flat projector according to the invention. In this variant, the electrodes distributed according to the invention heterogeneously on the surface operate in two or more groups, which can be switched, or operate independently. For this, the electrodes of a respective group are connected to their own specific cathodic or anodic connection of the group. The above is only possible through the use of dielectrically impeded discharges, which, due to their so-called positive current-voltage characteristic, make possible the parallel connection without problems of several partial discharges, or, electrode pathways to the electrode groups . Precisely in relation to the heterogeneous local division of the electrodes on the surface of the flat projector, it may be particularly appropriate to let the groups operating separately, respectively, on certain surface areas of the flat projector, especially high-density surface areas, which subsequently they can be switched on or off separately from each other. However, groups that operate separately can also be used to adjust the power of the lamp or to generate various surface patterns, to obtain special optical effects. In the example of essential application of the present invention are the optical warnings. They can be analog instruments, as shown in the example of realization, digital warnings, fields with warnings that communicate individual symbolized messages, determined by their lamps, as in the case of conventional control lamps, etc. In each case a specific surface shape is provided for illuminating the warning device, to which the geometry of the electrodes according to the invention is adjusted. Thus, in the area of the superficial forms to be illuminated, a luminous density, a higher luminous density or the highest of all are generated. In this way, the total luminous quantity generated, and thus the energy consumption, can be optimized according to the application, without for the flat projector in total, ie its housing geometry, or the discharge volume, require specific forms for the application or complicated. With the adjustment of the geometry of the electrodes, and therefore of the surface light density, according to the specific design of the warning device to illuminate or illuminate from the back, independently of aspects of energy saving, an additional degree of freedom is obtained in terms of ergonomics, that is, the clear structuring or better possibility of recognizing the warning device and its various representations and functions. This aspect can also be observed in combination with the separate commutability of the various groups, namely, in the sense that, for reasons of energy saving or ergonomics, various areas of the advertisement device can be operated with a different brightness, and thus, you can highlight certain areas and messages of the warning. Also, certain momentarily secondary zones of the warning device, etc., can be gradually diaphragmed by dark shading. These previous aspects have been shown here for warning devices as a special application, because in this case they seem especially interesting. However, they can play a role in completely different applications of the invention and must also be considered disclosed to them. The exemplary embodiment of the present invention illustrated in more detail below, relates to a warning device on a vehicle panel. This special case is a preferred field of application of the invention, namely, warning devices in road vehicles and roads, ships or aircraft, or motorized means of transport in general. Precisely in this field, the ergonomic requirements for warning devices, or, the fittings are especially high. A special case for the field of warning devices with regard to geometry, are the analog warnings in which, as illustrated in the example of embodiment, the following forms appear mainly for back lighting by a set electrode geometry : circles, circle segments, circle rings and circle rings segments. With the conventional technique, these shapes can practically only be clearly illuminated by the use of screens or masks, so that the invention can offer here essential advantages in terms of simplicity of technical work and energy consumption. The above is especially valid for circle rings or segments of circle rings and other high or curved shapes around their inner zone. As already said before, the invention should not be understood as limited to the field of signaling lamps or warning devices. Just to give an example of an application completely outside this field, in which the invention not only offers technical and ergonomic advantages, interior lamps are mentioned. Precisely because of the possibility of building with very low luminance densities in comparison with bulbs, lamps for large surfaces for interiors, also here the flat projector technique with dielectrically impeded discharge seems interesting .. With the local modulation according to the invention of the density surface lighting, a special decorative or aesthetic effect can be achieved in many aspects. For example, it can be imagined to have screens with graphic designs with correspondingly adjusted flat projectors, so that certain elements on the screen stand out specifically for their brightness, for example, in representations of figures for the children's room. On the other hand, for example, a flat projector lamp mounted flat on the wall of the room, by an aesthetic structure of the distribution of light density can be obtained a pleasant design. The above is especially valid in contrast to the external shape of a lamp like this, completely homogeneous and closed that can be achieved with the unit discharge volume. Of course, also in this case, there are various possibilities with respect to power control or design aspects, for the use of the group division of the electrodes already described for a separately switchable operation.

BRIEF DESCRIPTION OF THE DRAWINGS Next, the invention is illustrated with the help of a specific embodiment, which is schematically shown in Figure 1. This presents a plan view of a flat projector for a vehicle panel, for the back illumination of a combination instrument for the warning of the speed, the engine revolutions, the cooling water temperature and the level of the tank.

DETAILED DESCRIPTION OF THE INVENTION The outer edge of a discharge volume indicated by 1 is shown first, which is enclosed by two glass plates lying flat in the drawing plane and a joint projecting along the drawn edge . In the lower area of the figure, the glass bales protrude with a bead indicated with 3, beyond the discharge volume 1. On the right edge the pump connection piece (in closed state) used for the evacuation and filling With 2, the electrodes printed on one of the plates are indicated together, with cathode and anode extending respectively alternately, but in the Figure they do not differ more in detail. For most of its length, the electrodes 2 are located in the discharge volume 1 and with their part that is outside the discharge volume 1, they are connected in the area of the bead 3 to the supply circuit and to the electrical installation of the vehicle. The electrodes 2 are in three separate groups 2a, 2b and 2c, which respectively correspond to certain units, or warning contents. In particular, the left group 2a corresponds to an analog instrument to indicate the speed and, seen from its straight section going to the heel 3, follows the circular ring segment of this analog instrument. The corresponding is valid for group 2b which corresponds to a motor speed meter. In the case of group 2c, two instruments are connected, namely an indicator of the level of the tank and a thermometer of the cooling water. The purpose of seta separation in the present case is that, depending on the state of operation of the vehicle, only the information really necessary for the driver can be illuminated on the dashboard. This is, in any case, the speedometer 2a. When the engine speed limit is reached or if the driver wants it, warning 2b is added. Similarly, in case of almost empty tank or cooling water temperature still low or too high of the motor, as well as if desired by the driver, the third unit 2c can be connected to illuminate the other two instruments. In an exactly analogous way, if necessary, control and warning fields are connected to the displayed warning device. The corresponding electrode structures form other groups respectively, but for reasons of clarity are not shown in the Figure. You can think of the usual warnings, such as "activated handbrake", "high beams", etc. The electrodes 2 are printed on one of the two glass plates according to the screen printing process. They are coated with a dielectric glass barrier. The distance between both glass plates is approximately 7 millimeters, being joined with glass welding as a gasket through a glass frame that forms the outer edge of the discharge volume 1. The volume of discharge thus sealed contains as a filler download a Xe fill at approximately 100 millibar (= 10 kPa). Further details of the Xe excimer discharge lamp and pulse operation technique selected here can be found in the following applications, the disclosure of which is hereby referred to: WO 94/23 442, or DE-P 43 11 197.1 and WO 97/04625, or, DE 195 26 211.5. It also refers to the German application DE 196 36 965.7, which presents in its geometric structure structures of special electrodes for the definition of individual discharges between cathodes and anodes. For it, also in this embodiment, small protrusions are arranged on the cathodes. It also refers to a request from the same applicant with the title: "Signaling lamps and luminescent substances for them", file number EP 97122800.2, which presents the preferred luminescent substances for signaling lamps, in particular for excimer discharges of Xe.Also the disclosure of these two applications is included in this point. With the above example of embodiment it is clear that the invention, unlike the conventional use of flexed luminescent lamp or several bulbs, is characterized by a technically simple and rationally manufactured configuration and a distribution of the luminous surface density adjusted with Precision to the design of the warning device. In this way the use of energy and ergonomics are improved. In addition, flat projectors with dielectrically impeded discharge are also particularly advantageous, because they have a high resistance to shocks and vibrations, and their lifetime is limited in principle only by the stability of the luminescent substances used (maintenance). These advantages are important especially in motorized transport means, in which the repair or replacement work is high and a failure of a warning device, or, its illumination is especially unfavorable for safety reasons. The geometry of the flat projector can also be advantageous, which, as illustrated in this embodiment, can be adjusted particularly well in shape and size to the place of use, or installation. The invention also allows the use of simple housing shapes for flat projectors, in the present example the external shape of the discharge volume 1, including the bead 3, instead of complicated ring segments of circles with connecting pieces. Flatness is also advantageous under limited space conditions on a board, co-driver, etc. The same is true for light weight. The features of the invention disclosed in the present application and, in particular, in the embodiment example, may also be essential for that one individually or in other combinations than those presented.

Claims (3)

NOVELTY OF THE INVENTION Having described the above invention, it is considered as a novelty, and therefore, the content of the following is claimed as property: CLAIMS

1. A flat projector with dielectrically impeded discharge, with an electrode geometry (2a, 2b 2c) surface heterogeneous for the local modulation of the surface light density.

2. A flat projector according to claim 1, characterized in that the electrodes (2) are divided into groups that can be operated separately, for the independently switchable operation.

3. A projector according to claim 2, characterized in that the groups (2a, 2b, 2c) are distributed superficially and correspond to different lighting surfaces, which operate independently. . A projector according to claim as claimed in any of the preceding claims, with an optical warning device or signaling device and an electrode geometry (2a, 2b, 2c) adjusted to a surface shape to be illuminated by the warning or signaling device. . 5. A flat projector in accordance with that claimed in any of the preceding claims, with. an electrode geometry (2a, 2b, 2c) for the back illumination of analog warnings in the form of circles, circle segments, circle rings or ring circle segments. 6. A warning device or a signal lamp with a flat projector in accordance with the claim in any of the preceding claims, as a warning device in a vehicle, boat or plane. 7. An indoor lamp with a flat projector in accordance with claim 1 of any of claims 1 to 5.