Method and apparatus for multi-zoned illumination

FIELD OF THE INVENTION

0001The present invention is directed to a lighting apparatus and more specifically to a single lighting apparatus having a plurality of LED groups for multi-zoned LED based illumination.

BACKGROUND OF THE INVENTION

0002Current exterior lighting, such as for example street lights, using fluorescent tubes or mercury metal is inefficient and has several drawbacks. They generally consume more power and have a relatively short life. One alternative approach is to replace these light sources with light emitting diode (LED) based exterior lighting.

0003However, current LED based solutions use multiple LEDs to provide a required amount of lumens to illuminate a surface. Moreover, the LEDs are not independently controllable. That is, all of the LEDs must be adjusted at the same time.

0004<patcit id="pcit0001" dnum="US2000174472B"><text>US 200/0174472</text></patcit> proposes LED methods and systems for photographic and cinematography applications. Controlled LED illumination allows easy customization of these features to create a particular mood, and can be used to create light of desired saturation and hue.

0005<patcit id="pcit0002" dnum="US20060076908A"><text>US 2006/0076908</text></patcit> proposes lighting networks that include multiple LED-based lighting units, and user interfaces to facilitate control of such networks. It proposes that lighting units of a lighting network may be configured to generate one or more of variable color light, variable intensity light, and variable color temperature white light.

0006<patcit id="pcit0003" dnum="US7471051B"><text>US 7471051</text></patcit> proposes a low voltage lighting system supporting multiple independently controlled zones utilizing a plurality of semiconductor switches coupled to a plurality of transformers to produce a non-sinusoidal power output, and controlled by a digital controller that receives feedback from each zone in order to auto-sense the proper voltage for a plurality of connected loads.

0007<patcit id="pcit0004" dnum="US4924151A"><text>US 4924151</text></patcit> proposes a system for controlling power to multiple groups of lights that requires only a few controls. The system permits power to each group of lights to be adjusted independently and, at the same time, to be stored for later recall. Several combinations of power levels can be stored, and a particular combination can be selected, for example, by pressing a corresponding push button. In a preferred embodiment, a single control permits adjustment of any selected group, or groups, of lights.

0008<patcit id="pcit0005" dnum="US6046550A"><text>US 6046550</text></patcit> proposes a diagnostic apparatus for use in a light dimming circuit which selectively controls the current flow through a lighting load to adjust its luminous output. The dimming circuit has a controllably conductive device, such as a triac, connectable in series between an A.C. power source and a lighting load, and a control circuit which responds to a dimming level control signal to selectively apply a selected portion of an A.C. voltage waveform produced by the A.C. power source to the lighting load to adjust the RMS voltage across the load. The selected portion is determined by a firing angle at which the control circuit causes the controllably conductive device to conduct power during each half cycle of the A.C. waveform.

SUMMARY OF THE INVENTION

0009The present invention is directed to a multi-zoned lighting apparatus. One aspect of the invention provides a multi-zoned lighting apparatus comprising: at least one circuit board; at least one control circuit coupled to said at least one circuit board; and a plurality of light emitting diode (LED) groups coupled to said at least one control circuit and the at least one circuit board, wherein each LED group of said plurality of LED groups has at least one LED and wherein each LED group of said plurality of LED groups is independently controlled via said at least one control circuit based on a respective external signal received by said at least one control circuit from a respective external sensor; characterised in that said at least one control circuit is adapted to receive an external signal indicating that said respective external sensor associated with said respective one of said plurality of LED groups has been triggered by detecting an object; and in that an illumination level of said respective one of said plurality of LED groups is controlled by the at least one control circuit based on a type of object that is detected by said respective external sensor, a highest illumination level being used when said type of object detected is a person and an illumination level lower than said highest illumination level being used when said type of object detected is a vehicle.

0010A further aspect of the invention provides a corresponding method.

0011A further aspect of the invention provides a system for providing multiple points of multi-zoned illumination, the system comprising: a plurality of lighting apparatuses of the first aspect; at least one sensor coupled to the at least one control circuit of each one of said plurality of lighting apparatuses; and a central controller remotely located from said plurality of lighting apparatuses and in communication with said plurality of lighting apparatuses.

BRIEF DESCRIPTION OF THE DRAWINGS

0012So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, may be had by reference to embodiments, some of which are illustrated in the appended drawings, It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> depicts one embodiment of a single lighting apparatus having a plurality of LED groups;</li><li><figref idref="f0002">FIG. 2</figref> depicts one embodiment of the single lighting apparatus used to illuminate different zones;</li><li><figref idref="f0003">FIG. 3</figref> depicts one embodiment of the single lighting apparatus having different optical components fitted to the tight emitting diodes (LEDs);</li><li><figref idref="f0004">FIG. 4a</figref> depicts one embodiment of the single light apparatus when all illumination zones are off;</li><li><figref idref="f0005">FIG. 4b</figref> depicts one embodiment of the single light apparatus when a first sensor is triggered;</li><li><figref idref="f0006">FIG. 4c</figref> depicts one embodiment of the single light apparatus when a second sensor is triggered;</li><li><figref idref="f0007">FIG. 5</figref> depicts one embodiment of a system for providing multiple points of multi-zoned illumination;</li><li><figref idref="f0008">FIG. 6</figref> depicts a flow chart for one embodiment of a method for providing multi-zoned illumination using a single lighting apparatus;</li><li><figref idref="f0009">FIG. 7</figref> depicts a block diagram of one example of a control circuit for the single lighting apparatus having a plurality of LED groups; and</li><li><figref idref="f0010">FIGs. 8A</figref> and <figref idref="f0011">8B</figref> depict a circuit diagram of one example of the control circuit.</li></ul>

0013To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.

DETAILED DESCRIPTION

0014Embodiments of the present invention resolve the above noted problems associated with previously used lighting apparatuses for exterior lighting. For example, in one embodiment, the present invention uses a single light emitting diode (LED) based lighting apparatus having a plurality of independently controlled LED groups for multi-zoned illumination. Thus, the present invention provides a more efficient and cost effective option for exterior lighting. For example, various LED groups may be turned off or dimmed to a low setting until a person or object (e.g., a automobile, motorcycle and the like) is detected. Then, only a LED group associated with the zone that detected the person or object may be activated. Thus, costs savings is achieved by only powering up particular LED groups in the single lighting apparatus on an "as-needed" basis.

0015<figref idref="f0001">FIG. 1</figref> illustrates one embodiment of a lighting apparatus 100 of the present invention. The lighting apparatus comprises a plurality of LED groups 102, 104 and 106. Each of the plurality of LED groups 102, 104 and 106 may be coupled to at least one control circuit 105 on a single circuit board 110 or may be coupled to separate circuit boards 110. In one embodiment, the control circuit 105 may comprise a controller (e. g. , a central processing unit (CPU) and associated computer readable mediums, e. g. , RAM, ROM, hard disk drive, floppy disk and the like for storing instructions) and one or more switches for controlling the LED groups 102, 104 and 106 independently. Alternatively, the control circuit 105 may comprise ancillary devices such as wiring, resistors, capacitors, inductors, gates and the like designed and implemented to control each of the plurality of LED groups 102, 104 and 106 independently. Those skilled in the art will recognize that any type of circuit design may be used to independently control the plurality of LED groups 102, 104 and 106 independently.

0016<figref idref="f0009">FIG. 7</figref> illustrates a block diagram of one example of a control circuit 105. The control circuit 105 may include a power source 702, a power supply 704, a LED current control 706, an external control signal module 708, a primary processing and control module 710, a feedback and monitoring module 712 and a feedback processing module 714. The LED current control 706 may be coupled to each one of the plurality of LED groups 102, 104 and 106. The feedback and monitoring module 712 may monitor various data via circuits 718 and 720 from each of the LED groups 102, 104 and 106. For example circuits 718 may provide LED temperature information and circuits 720 may provide current information.

0017In one embodiment, the external control signal module 708 and the primary processing and control module 710 may communicate with one another via two way communications represented by arrows 716. The external control signal module may be, for example, an external sensor as discussed below with respect to <figref idref="f0007">FIG. 5</figref>. One exemplary detailed circuit diagram of the above control circuit 105 is illustrated by circuit 800 in <figref idref="f0010 f0011">FIG. 8</figref>.

0018Referring back to <figref idref="f0001">FIG. 1</figref>, each one of the plurality of LED groups 102, 104 and 106 may include at least one LED 108. In one embodiment, the LED 108 may be any type of LED 108 that has enough light output to illuminate an outdoor area. For example, the LED 108 may provide illuminance (lux) of at least 10 lumens per square meter or luminance (cd/m²) of at least 1 candela per square meter.

0019<figref idref="f0001">FIG. 1</figref> illustrates that LED group 102 has 4 LEDs 108, LED group 104 has 4 LEDs 108 and that LED group 106 has 4 LEDs 108. Those skilled in the art will recognize that any number of LEDs 108 may be included in each LED group and the present invention is not limited to any specific number of LEDs 108. In addition, although only three LED groups 102, 104 and 106 are illustrated in <figref idref="f0001">FIG. 1</figref>, those skilled in the art will recognize that any number of LED groups may be used.

0020In one embodiment, each one of the plurality of LED groups 102, 104 and 106 may be independently controlled. That is, an illumination level of the LED 108 of any one of the LED groups 102, 104 or 106 may be adjusted without adjusting an illumination level of the other LED groups. For example, the illumination level of the LEDs 108 on LED group 102 may be adjusted without adjusting the illumination level of the LEDs 108 on the remaining LED groups 104 and 106. Illumination level may be defined herein as including on (ie, fully on), off and any gradation of illumination between on and off.

0021Notably, the plurality of LED groups 102, 104 and 106 are included in a single lighting apparatus 100. Thus, only a single lighting apparatus 100 needs to be powered to independently control three different LED groups 102, 104 and 106 as opposed to installing, and separately powering, three separate light fixtures to illuminate three different zones. In addition, during installation, only a single lighting apparatus 100 needs to be installed, thus saving time and labor costs for installation.

0022The ability to independently control the plurality of LED groups 102, 104 and 106 may be advantageously used to illuminate different zones. <figref idref="f0002">FIG. 2</figref> illustrates one embodiment of how the lighting apparatus 100 may be used to illuminate different zones 202, 204 and 206 of a surface 208.

0023Each one of the LED groups 102, 104 and 106 may be associated with a different zone 202, 204 and 206. For example, the LEDs 108 in LED group 102 may be positioned or configured such that when LED group 102 is activated only zone 202 is illuminated. Accordingly, the LEDs 108 in LED group 104 may be positioned or configured such that when LED group 104 is activated only zone 204 is illuminated. The LEDs 108 in the LED group 106 may be similarly arranged such that only zone 206 is illuminated when LED group 106 is activated.

0024Notably, light emitted from the LEDs 108 of each one of the plurality of LED groups 102, 104 and 106 are emitted at a different angle or a different direction. That is, light emitted from LEDs 108 of LED group 102 are emitted at a different angle than light emitted from LEDs 108 of LED groups 104 and 106, respectively. There may be some overlap between the illumination zones, however a majority of the peak illumination of the LEDs 108 of each one of the LED groups 102, 104 and 106 falls within their respective zones, 202, 204 and 206. Said another way, in one embodiment, the light emitted from the LEDs 108 of each one of the plurality of LED groups 102, 104 and 106 are not in a parallel direction.

0025In one embodiment, rather than positioning each one of the LEDs 108 to face in a different direction to illuminate a respective zone 202, 204 and 206, the LEDs 108 of each one of the plurality LED groups 102, 104 and 106 may all face the same direction and an optical component may be coupled to the LEDs 108 to re-direct the light emitted from the LEDs 108 in different angles or in different directions. This is illustrated as one embodiment in <figref idref="f0003">FIG. 3</figref>.

0026<figref idref="f0003">FIG. 3</figref> illustrates one embodiment of the light apparatus 100 having LEDs 108 fitted with optical components 302, 304 and 306. The optical components 302, 304 and 306 may be a lens or a reflector. The optical components may be designed to move light output by the LEDs 108 or a LED group 102, 104 or 106 in a desired direction. In addition, the optical components 302, 304 and 306 may be the same for each of the LEDs 108 or each of the LED groups 102, 104 and 106 or may be different for each of the LEDs 108 or each of the LED groups 102, 104 and 106. For example, each one of the LEDs 108 in LED group 102 may be fitted with a first optical component 302. Each one of the LEDs 108 in LED group 104 may be fitted with a second optical component 304. Each one of the LEDs 108 in LED group 106 may be fitted with a third optical component 306.

0027In an alternative embodiment, a first optical component 302 may be coupled to the circuit board 110 of the LED group 102. In other words, a single first optical component 302 may be used to cover all of the LEDs 108 of the

0028LED group 102, rather than individually coupling the first optical component 302 to each one of the LEDs 108 of the LED group 102. Similar configurations may be made with the second optical component 304 and the LEDs 108 of the LED group 104 and the third optical component 306 and the LEDs 108 of the LED group 106.

0029Thus, when the lighting apparatus 100 is manufactured, all of the LEDs 108 may be placed facing the same direction. Then using the optical components 302, 304 and 306, light emitted from the LEDs 108 may be redirected to illuminate a particular zone associated with a respective LED group 102, 104 or 106. For example, referring back to <figref idref="f0002">FIG. 2</figref>, the first optical component 302 may be used to re-direct light emitted from LEDs 108 in the LED group 102 towards zone 202. The second optical component 304 and the third optical components 306 may function similarly to illuminate zones 204 and 206, respectively.

0030In one embodiment, external sensors (not shown) may be deployed to activate a particular LED group when the sensor is triggered. A sensor may be remotely deployed in each illumination zone and be in communication with one of the plurality of LED groups 102, 104 and 106. The sensor may be either wirelessly in communication with or directly wired to one of the plurality of LED groups 102, 104 and 106. Any type of sensor may be used to detect motion or the presence of a person or physical object such as, for example, a motion sensor, an induction loop, RADAR, a proximity sensor, an acoustic sensor, a pressure sensor and the like.

0031<figref idref="f0004 f0005 f0006">FIGs. 4a-4c</figref> illustrate one embodiment of how sensors may be used to activate a particular LED group 102, 104 or 106 for multi-zoned illumination.

0032<figref idref="f0004">FIG. 4a</figref> illustrates one of many possible applications of the lighting apparatus 100. In <figref idref="f0004">FIG. 4a</figref> a parking garage is used as one possible application. The lighting apparatus 100 may be installed over the surface 208. As illustrated in <figref idref="f0004">FIG. 4a</figref>, no persons or objects are detected by the sensors (not shown). Consequently, all of the LEDs 108 of the respective ones of the plurality of LED groups 102, 104 and 106 are turned off or are dimmed to the lowest illumination level.

0033In <figref idref="f0005">FIG. 4b</figref>, a person or object 400 is detected in zone 204. For example, a person could be entering their parked car in zone 204 or a car could be approaching zone 204 in the parking garage. In any case, when the person or object 400 triggers a sensor in zone 204, the information may be communicated to a particular LED group in the lighting apparatus 100. Thus, a particular LED group associated with zone 204 may be activated. In the present example, the LED group 104 may be associated with the sensor in zone 204.

0034Thus, triggering the sensor associated with zone 204 activates the LED group 104. As a result, an illumination level of the LEDs 108 in the LED group 104 may be adjusted to illuminate zone 204. For example, if the LEDs 108 in the LED group 104 were off, the LEDs 108 in the LED group 104 may be turned on and adjusted to a desired or pre-determined illumination level.

0035In one embodiment, different illumination levels may be used depending on whether a person or a vehicle is detected in zone 204. For example, when a person is detected in zone 204, the LEDs 108 in the LED group 104 may be adjusted to a maximum illumination level. Alternatively, when a car is detected in zone 204, the LEDs 108 in the LED group 104 may be adjusted to a lower illumination for energy and cost savings as the car will typically have headlights and full illumination is not needed. In one embodiment, the sensor may distinguish the difference between a person and a car based upon a speed at which the object is moving or via image recognition methods. However, those skilled in the art will recognize that other methods may be used to differentiate between people and objects.

0036Notably, in <figref idref="f0005">FIG. 4b</figref>, while the illumination level of the LEDs 108 in the LED group 104 is adjusted, the remaining LED groups 102 and 106 remain unchanged. That is, the illumination level of the LEDs 108 in the LED group 104 is independently controlled with respect to the other LED groups 102 and 106.

0037Referring now to <figref idref="f0006">FIG. 4c</figref>, a second person or object 402 is detected in zone 202. For example, a car could be detected in zone 202 of the parking garage. When the person or object 402 triggers a sensor in zone 202, the information may be communicated to a particular LED group in the lighting apparatus 100. Thus, a particular LED group associated with zone 202 may be activated. In the present example, the LED group 102 may be associated with the sensor in zone 202.

0038Thus, triggering the sensor in zone 202 activates the LED group 102. As a result, an illumination level of the LEDs 108 in the LED group 102 may be adjusted to illuminate zone 202. For example, if the LEDs 108 in the LED group 102 were off, the LEDs 108 in the LED group 102 may be turned on and adjusted to a desired or pre-determined illumination level.

0039Notably, adjusting the illumination level of the LEDs 108 in the LED group 102 has no effect on the LEDs 108 in the LED groups 104 and 106, respectively. For example, the LEDs 108 in the LED group 104 remain illuminated while object 400 is still in zone 204. In addition, the LEDs 108 in the LED group 106 remain off or in the lowest illumination setting while no person or object is detected in zone 206. Moreover, the illumination level of the LED groups 102 and 104 may be different.

0040Although <figref idref="f0004 f0005 f0006">FIGs. 4a-4c</figref> are discussed with respect to using the lighting apparatus 100 in a parking garage, those skilled in the art will recognize that the lighting apparatus 100 may be used in other environments. For example, the lighting apparatus 100 may be used as street lighting or to light walkways. Thus, the environments discussed herein should only be viewed as examples and not be considered limiting the present invention.

0041The lighting apparatus 100 may be used with other lighting apparatuses 100 to form a more complicated system. <figref idref="f0007">FIG. 5</figref> illustrates a system 500 for providing multiple points of multi-zoned illumination. For example, the system 500 illustrated in <figref idref="f0007">FIG. 5</figref> may be utilized on a street with multiple lanes of traffic. Each one of the plurality of LED groups in the lighting apparatus 100 may be used to illuminate a single lane of traffic. A plurality of lighting apparatuses 100 may be situated along a street each having the plurality of LED groups to selectively illuminate lanes of traffic along a street as needed.

0042Each one of the plurality of lighting apparatuses 100 may each have one or more sensors 502. As discussed above, the sensor 502 may be an external sensor remotely located form a respective lighting apparatus 100 and in communication with the respective lighting apparatus 100. A sensor 502 may be placed in each lane and in communication with a respective one of the plurality of LED groups. Alternatively, an induction loop 510 may be used in each lane and in communication with a respective one of the plurality of LED groups. In yet another embodiment, a different type of sensor may be used in each lane.

0043When the sensor 502 or the induction loop 510 in a lane of the street senses a passing car, a LED group associated with the sensor 502 or induction loop 510 may be activated. Thus, LEDs associated with the activated LED group may illuminate the lane having the passing car, while the LEDs associated with the remaining LED groups in the unused lanes remain off or at a minimum illumination level. In one embodiment, the sensor 502 or the induction loop 510 may be placed a calculated distance before the lighting apparatuses 100 such that a first lighting apparatus 100 may have enough time to receive communications from the sensor 502 or the induction loop 510 and activate the LEDs of an appropriate LED group. For example, the distance may be based upon an average speed of cars using the street and the amount of time for the lighting apparatuses 100 to receive communications and activate the LEDs of an appropriate LED group.

0044Moreover, the plurality of lighting apparatuses 100 may be in communication with one another. In one embodiment, the plurality of lighting apparatuses 100 may communicate using radio frequency (RF) point-to-point communications. This may be used to communicate information between the plurality of lighting apparatuses 100 such that they may activate LEDs down the road for the particular lane as the car is moving.

0045To illustrate, a first sensor 502 or induction loop 510 detects a passing car, thereby activating LEDs of a particular LED group of a first lighting apparatus 100. Subsequently, the first lighting apparatus 100 may communicate with a second lighting apparatus 100 down the street informing it that a car is approaching. Thus, the second lighting apparatus 100 may activate a particular LED group associated with the same lane as illuminated by the particular LED group in the first lighting apparatus 100 in anticipation of the approaching car. This may then be repeated again by having the second lighting apparatus 100 send a communications to a third lighting apparatus 100 and so forth.

0046As a result, a sensor 502 or an induction loop 510 need not be placed with every one of the plurality of lighting apparatuses 100. For example, a sensor 502 or an induction loop 510 may be placed every 10 lighting apparatuses to ensure the car is still in the illuminated lane. However, if the car turns off of the street before the next sensor, then the subsequent plurality of lighting apparatuses 100 down the street would not be activated.

0047Other types of logic may be implemented to turn off the plurality of lighting apparatuses 100 after they are turned on. For example, if the first lighting apparatus 100 is turned on and the first sensor 502 does not detect a passing car within a predefined period of time, the lighting apparatus 100 may automatically turn off. Alternatively, if a second sensor (not shown) detects the passing car at a second lighting apparatus, then the second sensor may communicate back to the first lighting apparatus 100 to instruct the first lighting apparatus 100 to turn off. Those skilled in the art will recognize that any logic may be implemented to turn off the plurality of lighting apparatuses 100 after they are turned on.

0048The plurality of lighting apparatuses 100 may also be in communication with a remotely located central controller 504 via a hub 506. In one embodiment, the central controller 504 may comprise a processor element (e.g., a CPU), a memory, e.g., random access memory (RAM) and/or read only memory (ROM) and various input/output devices (e.g., computer readable mediums or storage devices, including but not limited to, a tape drive, a floppy drive, a hard disk drive or a compact disk drive, a receiver, a transmitter, a speaker, a display, a speech synthesizer, an output port, and a user input device (such as a keyboard, a keypad, a mouse, alarm interfaces, power relays and the like)).

0049In one embodiment, the central controller 504 may communicate with the hub 506 via a global system for mobile (GSM) communications network. The hub 506 may communicate with the plurality of lighting apparatuses 100 via RF point-to-point communications.

0050In one embodiment a mobile node 508 may also be used to communicate with the plurality of lighting apparatuses 100 via the hub 506. For example, the mobile node 508 may communicate with the hub 506 via a short message service (SMS) protocol.

0051In one embodiment, the central controller 504 and/or the mobile node 508 may be used to monitor and/or control each one of the plurality of lighting apparatuses 100. For example, if maintenance needs to be performed on one of the plurality of lighting apparatuses 100, the central controller 504 may be used to temporarily disable the lighting apparatus 100. Alternatively, the central controller 504 may be used to ensure the plurality of lighting apparatuses 100 remain turned on if emergency personnel are present or there is an accident. The central controller 504 may also be used to collect information from each of the plurality of lighting apparatuses 100 such as life, power readings, status, error alarms, etc. Thus, the system 500 provides an integrated communications network of the plurality of lighting apparatuses 100.

0052In one embodiment, to prevent inadvertently triggering the sensors by animals or flying debris, one or more thresholds may be used by the sensors and the lighting apparatuses 100. For example, the sensor may only activate one of the plurality of LED groups in the lighting apparatus 100 if an object is moving above a certain speed, e.g. around the speed limit associated with the street.

0053Notably, the above embodiment may provide substantial cost savings for street lighting. For example, in rural roads that are infrequently travelled, the lights may remain off until a moving car or object is detected rather than having the lights remain on throughout the light when the street is not in use.

0054<figref idref="f0008">FIG. 6</figref> illustrates one embodiment of a flow chart for a method 600 for providing multi-zoned illumination using a single lighting apparatus. The method 600 begins at step 602.

0055At step 604, the method 600 powers a single lighting apparatus having a plurality of LED groups, each one of the plurality of LED groups having at least one LED. As discussed above, one embodiment of the present invention only requires a single power source to a single lighting apparatus for illuminating multiple zones.

0056At step 606, the method 600 controls each one of the plurality of LED groups independently of one another via a respective external sensor that controls a respective one of said plurality of LED groups when triggered. As described above, even though the single lighting apparatus 100 is powered, all of the LEDs in the lighting apparatus 100 need not be all at the same illumination level. Notably, the LEDs may be associated with different LED groups and adjusted or powered on or off independently of the other LED groups. The method 600 concludes at step 608.

0057While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the scope of the present invention should not be limited by any of the above-described embodiments, but should be defined only in accordance with the following claims.