Ceiling tile transmitter and receiver system

Abstract: A ceiling tile transmitter and receiver system having at least one transmitter/receiver device located in a ceiling panel either during or after the ceiling panel fabrication process. In one embodiment one or more pockets of variable size and shape are created on a surface of the ceiling panel during or after the ceiling panel manufacturing process and then a transmitter/receiver device, such as an RF antenna, is rigidly fixed in the pocket In another embodiment, the transmitter/receiver device is embedded in the front side (lower surface) of the ceiling tile and a "scrim" covering is placed over it to secure it in place. The transmitter/receiver device can also be embedded inside the ceiling tile or rigidly fixed on an upper, lower or side surface of the ceiling tile. The transmitter/receiver device can be encased on the front surface of the ceiling tile, where the transmitter adds to, or integrates into, the overall aesthetics of the ceiling tile. Various combinations of these embodiments can be used with a single ceiling tile. A high temperature resistant "place holding" structure that can withstand the ceiling tile treatments can be provided and later removed to allow the installation of the transmitter/receiver device.

Description: The invention relates to a ceiling tile transmitter and receiver system for transmitting and receiving electromagnetic signals in a defined area of a building space comprising a ceiling tile or panel including a front surface to be faced towards the room, a back surface to be faced towards the plenum, and lateral surfaces and at least one transmitter/receiver device supported by the ceiling tile. During recent years in the designing or retrofitting of buildings, there has become an ever more pressing need to increase design flexibility. With the pervasive use of digital electronics, building designs now need to incorporate such infrastructure as digital communications, Internet connections, local area network connections, increased voice communications capability, and the like. Also, more and more appliances, such as security, sound, paging, heating, ventilating and air conditioning (HVAC), lighting, heating and cooling systems are digitally controlled. This technology has placed even more stress on the building design which has to include communications bus systems between the various appliances and some central control system. The building management systems that control these appliances have also evolved. Computer control is now fundamental to building management systems. This has lead the way to the measurement and control of the aforementioned appliances. By adding computer control, great savings in energy costs are achieved in terms of turning devices on or off, or adjusting appliances, based upon user needs or even user projected needs. Also, the remote control of systems has enabled the building management function to be done off premises. Building management systems contain various appliances for building service functions, a control system for control and regulation of the appliances, and a communication bus for communication of signals between the control system and the appliances. Such a system is used for the central management of building functions, such as lighting, heating, and ventilation etc. The appliances include, for example, lighting, heating equipment, air-conditioning devices or electrically movable window blinds. In office buildings and commercial and industrial complexes, the central management of energy consumption services allows a relatively easy adjustment of the level of light or temperature to the actual existing demand at any moment. This results in considerable savings of energy and costs. Such a system precisely monitors energy consumption and enables accurate billing of the users in a multi-user building. Such a building management system can also be used for peak saving purposes to comply with the requirements of an electric company to keep power consumption below an agreed maximum leveL Many building management systems have different capability, which leads to having different transmitter/receiver devices in the same ceiling system, or more importantly, a different method to integrate these different transmitter/receiver devices. For instance, one communication system may require one frequency setting whereas another communication system may require an entirely different frequency setting. Also, one communication system may require a certain power or gain, whereas another would be different. Antenna gain is related to antenna size, and therefore if more gain is needed, the size of the antenna is increased. Aesthetics have become of primary importance in building ceiling systems. Many ceiling manufacturers offer a wide variety of designs and colors for their suspended ceiling systems. Furthermore, many appliances are attached or hung from the ceiling panels or ceiling suspension grids. Today unfortunately, theft and vandalism have become issues, and at times devices such as smoke detectors, fire alarms, lighting fixtures, etc. have been vandalized. In the known systems, the local controllers and the appliances are connected to the communication bus by wires. In a modern office building or commercial complex this is a drawback as space layouts are often changed. Changing space layouts almost always requires displacement of the appliances and frequently the tearing down and rebuilding of internal walls. To achieve a flexible floor layout at low cost, a minimum amount of wiring in the walls is required. However, it is also essential that the users of a building have full control over the location of the appliances; consequently, placing appliances only at predetermined locations is unacceptable. In current systems, a hard-wired communication bus is used to connect to the local room wireless transmitter/receiver systems. These wireless transmitter/receiver systems are used to communicate between the bus and the appliances in the room. However, the communication bus system is still a "hardwired" configuration. This leads to a decrease in flexibility, since a room's square footage may change over time, and therefore the transmitter/receiver devices and the hardwired communication bus may also need to be changed or rerouted. Rerouting or changing current transmitter/receiver devices requires modifying ceiling panels (drilling/punching/cutting) and replacing the ceiling tiles that had the transmitter/ receiver device in it. Another problem occurs in that transmitter/receiver devices have poor aesthetics when suspended from ceiling panels. After much design and expense have been invested in a ceiling panel system, a rod or dish antenna system is added to the ceiling panel to allow it to communicate to appliances below. There has not been much consideration given in terms of the room aesthetics of a joint system of antennas and ceiling panels. Another problem occurring in the industry is vandalism and theft. When devices can be physically seen, they are more prone to be tampered with or removed. Still another problem occurs in the design of ceiling tile panels that can be integrated with antennas of different sizes. In the manufacturing and sales of ceiling tiles, processes have to be made flexible to account for all of the different part numbers corresponding to transmitter/receiver devices. The prior art of the generic kind according to GB 2 283 642 A discloses a suspended ceiling consisting of runners, the flanges of which support the ceiling tiles. One of these ceiling tiles is modified by having mounted thereabove a base station for a radio telephone system. The base station has an H-field flat antenna printed on a printed circuit board. The antenna is coplanar with the ceiling tile and may be mounted on the upper or lower surface thereof. The underside of this modified ceiling tile matches the remaining ceiling tiles of the suspended ceiling. US 4 923 032 discloses a suspended ceiling comprising a grid structure of inverted T-shaped runners supporting ceiling tiles of standard size. One or more of the ceiling tiles can be replaced by a loudspeaker module of the same size. This module consists of a mounting panel corresponding in size and shape to a ceiling tile. In the mounting panel a pair of speakers is installed. For enclosing the rear portions of the speakers and other system components a shallow rear housing is attached to the mounting panel provided with electrical connectors on its rear side, while on the opposite side a demountable grill is attached to the mounting panel to enclose the front faces of the speakers. The demountable grill indudes an acoustically transparent covering of cloth or the like which may be colored and/or textured to match the surface of the adjacent ceiling tiles. Between the mounting panel and the supporting flanges of the grid an insulating foam material is located to provide a vibration absorbing interface between the module and the supporting grid. The deformable grill extends beyond the plane of the room facing surfaces of the runners. It is the object of the invention to overcome the above-stated problems and to provide a ceiling tile transmitter and receiver system of the generic kind maintaining the shape and aesthetics of the whole tile independent of the size and shape of the transmitter/receiver devices. This object is achieved with the system of the generic kind by providing at least one pocket in at least one surface of the front, back and lateral surfaces, in which pocket the transmitter/receiver device is inserted and rigidly affixed. it is preferred that the at least one pocket is provided in the front surface and that a scrim cover is placed over the entire front surface. It is convenient that the at least one pocket is formed in the at least one surface by cutting with a router, by stamping after wet manufacturing of the ceiling tile or by placing a ceramic placeholder for the pocket during forming and curing of the ceiling tile and removing the placeholder thereafter. Advantageously the transmitter/receiver device is located above the plane formed by the room facing surface of a ceiling suspension system. The basic concept of the present invention is to attach or embed at least one transmitter/receiver device in a ceiling panel either during or after the ceiling panel manufacturing process. In a first embodiment at least one pocket is created on the backside of the ceiling panel, of variable size and shape, by the ceiling panel manufacturing process and then a transmitter/receiver device, such as an RF antenna, is rigidly fixed in the pocket after ceiling panel manufacturing. In another embodiment, the transmitter/receiver device is inserted and affixed in a pocket in the front side of the ceiling tile and a "scrim" covering is placed over it. The ceiling tile transmitter and receiver system described herein can be incorporated into a wireless communication plane providing an umbrella of connectivity for devices. Such devices can span a range from appliances to computer clients (workstations, laptops, hand-held devices, etc.). In a wireless communication system, RF antennas, transceivers and receivers can be inserted in the pockets in the ceiling tile and affixed therein. The components of the transmitter/receiver system include miniature antennas, single chip transceivers, sensors, power supplies, microprocessors, etc. The transmitter/receiver system in one preferred embodiment employs an omnidirectional multistrip antenna that has a toroidal field pattern and provides omnidirectional coverage in any plane around the long axis of the antenna and two lobes in any plane parallel to the long axis. Such microstrip antenna and also omnidirectional air-loaded patch element antennas are available for different frequencies and application requirements. One exemplary antenna that can be used is the Microsphere omnidirectional microstrip antenna available from Xertex Technologies. Although the present invention has been described in the context of the manufacturing of ceiling tiles that incorporate transmitter/receiver devices affixed in pockets either during or after the manufacture of ceiling tiles, the invention is equally applicable to the installation of transmitter/receiver devices in existing ceiling tiles. To serve that end, it is a simple extension to provide a retrofitting kit to building supply vendors, building contractors or directly to other parties that includes the tools and additional hardware required to form pockets in existing ceiling tiles to accommodate transmitter/receiver devices and to rigidly affix the transmitter/receiver devices in the pockets. There are several different ceiling tile manufacturing processes that can be used for creating pockets for the transmitting/receiving devices. A high temperature resistant "place holding" structure that can withstand the ceiling tile treatments can also be provided that can be removed later to allow the mounting of the transmitter/receiver device. The invention is better described in the following detailed description of the invention with reference to the accompanying drawing figures. Fig. 1 illustrates a ceiling tile with formed or cut pockets on the back surface for rigidly fixing antennas or other electronic devices. Fig. 2 illustrates a ceiling tile with formed pockets on the back surface with one pocket containing a transmitter/receiver device. Fig. 3 illustrates a ceiling tile with formed pockets on the front surface for containing a transmitter/receiver device, and a scrim cover for attaching to the front surface. Fig. 4 illustrates an embedded transmitter/receiver device that does not form part of the present invention. In a first embodiment of the invention, at least one pocket is created on the backside of the ceiling panel during the ceiling panel manufacturing process, wherein each pocket can be of a different size and shape, and antennas, or other electronic components, are rigidly fixed in these pockets after ceiling panel manufacturing. Shown in Fig. 1 is a section from a ceiling tile 1, with back surface (facing towards the plenum) 10 and a front surface (facing towards the room) 20. Throughout this description, the terms "back surface" and "upper surface" are used interchangeably. Likewise "front surface" and "lower surface" are interchangeable. Depicted in the figure are pockets 2, 3, and 4. These pockets can be made of different dimensions in width, length and depth, to account for various possible sizes and shapes of the transmitter/receiver antennas or other electronic devices to be inserted. A ceiling tile router can be used to cut pockets 2, 3, 4 after the ceiling tiles are fully manufactured. These pockets also can be stamped on the back side after the ceiling tile is wet manufactured. Alternately, these pockets can be defined by placing a ceramic placeholder during the forming process of the ceiling tile, so that the ceiling tile is wet-formed and then cured. When the ceiling tile dries, the ceramic placeholders are removed. These are just a few of the possible methods of creating these pockets. Fig. 2 illustrates a ceiling tile 1 with an antenna 50 having electrical leads 60, and which can be used for the transmission or reception of radio frequency (RF) signals. The antenna is placed in the pocket 2 of the ceiling tile 1. The pockets are designed so as to allow any of multiple sizes and shapes of antennas to be placed in the pockets. These antennas can simply be glued or clamped into the pocket. The electrical leads are usually of the coaxial type with easy to connect connectors. A second embodiment is depicted in Fig. 3 with a ceiling panel 1 having a top surface 203 and a bottom surface 202. This structure is shown inverted from the structures illustrated in Figs. 1 and 2 in which the back of the ceiling tile faces up, whereas in Fig. 3 the front of the ceiling tile faces up. Pockets 30 and 31 are shown, fabricated as before. Antenna 50 is placed/fixed in pocket 30, with electrical leads 51 being routed out through the back of the ceiling paneL A hole is formed from the pocket to the back of the ceiling tile by a drill or other means. The scrim 201, normally used in aesthetic ceiling tiles, is a sheath stretched and glued over the front face 203 of the ceiling tile 1. As can be seen, this scrim covers both the ceiling tile 1 and the antenna 50. In high volume manufacturing of ceiling tiles, many pockets may be formed in the ceiling tile but not filled with an antenna, as discussed above. In the example of Fig. 3, the scrim also covers an empty pocket 31. In the case of some pockets being too wide or too deep to effectively cover without the scrim or its process deforming the scrim in that region, a dummy antenna structure is placed in the pocket. The antenna and dummy structure, if any, are glued into place. Another method to completely encapsulate an antenna is to form a deep pocket in the ceiling tile as illustrated in Fig. 1. Next, the antenna is fixed in the deep pocket followed by a back fill of the rest of the opening with a plug of ceiling tile that is glued in, or form a hardening paste in the antenna.

Claims: Ceiling tile transmitter and receiver system for transmitting and receiving electromagnetic signals in a defined area of a building space comprising a ceiling tile (1) including a front surface (20, 203) to be faced towards the room, a back surface (10, 202) to be faced towards the plenum, and lateral surfaces and at least one transmitter/receiver device supported by the ceiling tile (1) characterized by at least one pocket (2, 3, 4; 30, 31) in at least one surface of the front, back and lateral surfaces (10, 20, 203), in which pocket (2, 3, 4; 30, 31) the transmitter/receiver device is inserted and rigidly affixed. System according to claim 1, characterized in that the at least one pocket (30, 31) is provided in the front surface (203) and in that a scrim cover (201) is placed over the entire front surface (203). System according to claim 1 or 2, characterized in that the at least one pocket (2, 3, 4; 30, 31) is formed in the at least one surface (10, 20, 203) by cutting with a router, by stamping after wet manufacturing of the ceiling tile (1) or by placing a ceramic placeholder for the pocket (2, 3, 4; 30, 31) during forming and curing of the ceiling tile (1) and removing the placeholder thereafter. System according to one of the preceding claims, characterized in that the transmitter/receiver device is located above the plane formed by the room facing surface of a ceiling suspension system.

Inventors: CRONIN JOHN E, FRECSKA SANDOR A, CRONIN, JOHN E., FRECSKA, SANDOR A.
Applicants: ARMSTRONG WORLD IND INC, ARMSTRONG WORLD INDUSTRIES, INC.
Application year: 2000
Main classification: G01S13
IPC codes: H01Q1, H01Q23, E04B9