Multi-zone, multi-scene lighting control system
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus for individually controlling the intensity of multiple lighting groups, and more specifically, relates to a control system which allows many groups of lights to be controlled with few controls. 
     2. Description of the Related Art 
     In many situations where artificial lighting is used to create an environment conducive to a variety of activities, such as in a hotel lobby; or where it is desirable to emphasize certain features or areas in an architectural space, it is advantageous to be able to control the incident light intensity of the areas independently, so that lighting can be optimized in each area. Areas may be illuminated by groups (or &#34;zones&#34;) of lighting fixtures that are controlled together. A control panel, adapted to control power (and, thus, light intensity) to each zone, provides a convenient way to create a desired ambience or &#34;scene&#34;; i.e., a particular combination of zone intensities. 
     A typical control panel designed to provide this function incorporates an array of slide actuators, each of which controls the light output of a zone. A scene can be created by setting the position of each slide actuator in the array to a desired level. More versatile control panels typically include more than one array of slide actuators to provide additional scenes. A selector knob or push buttons are used to select among the preset scenes that are mechanically stored as arrays of slide actuator positions. 
     An Aurora® control panel, manufactured by Lutron Electronics, Coopersburg, Pa., provides four arrays of six slide actuators for controlling up to six zones of lights. Because it is desirable to keep the wall-mounted control panel small and simple, electronic signals are sent to a remote dimming cabinet which dims each zone to the instructed level. The remote cabinet may be mounted in an electrical closet, where load wires are more accessible and heat dissiptation is less of a problem. Any one of four preset scenes are recalled by actuating corresponding push buttons. 
     It is often desirable to control a large number of zones and create many preset scenes that can be recalled later. If, for instance, twenty-four zones of lights were to be controlled, with eight possible preset scenes, a control panel similar to the Aurora® would have eight arrays, each containing twenty-four slide actuators, for a total of 192 slide actuators. Unfortunately, a panel this large would be bulky, cumbersome to use, and costly to produce. 
     Some other control panels employ a single array of slide actuators to independently adjust lighting zone intensities; i.e., only one slide actuator is used per zone. Preset scenes are stored in an electronic memory, such as a static RAM integrated circuit chip. The Series-7, manufactured by Prescolite Controls, of Carrollton, Texas, incorporates a single array of twelve slide actuators, to control the same number of zones, and an electronic memory for storing up to eleven preset scenes. Once a scene is set via the actuator array, it can be stored in an electronic memory by pressing a &#34;record&#34; button, thereby storing the position of each actuator in the array. Scenes are recalled by pressing the corresponding scene buttons. 
     One disadvantage of this control system is that scenes cannot be &#34;fine-tuned&#34;. Suppose, for example, that you have consecutively set a number of scenes to your liking. In reviewing scene one, you decide that zone five requires adjustment. At this point, the slide actuator array corresponds to the most recently set scene, even though the lighting corresponds to scene one. In order to make this correction to scene one, you must readjust all slide actuators to create a new scene one and record it over the old scene. This can be quite a nuisance, for example, when twenty-four zones of lights are being controlled and more than a few fine adjustments are required. 
     To overcome this inconvenience and to create a simpler control, the Omega control system, manufactured by Electronics Diversified, of Hillsboro, Oregon, incorporates an encoder wheel, which provides a single intensity adjustment for all zones. Zones within a scene are adjusted by selecting the appropriate zone, adjusting the zone intensity via the encoder wheel, and then actuating the record button to store the change. Thus, it is possible to select, adjust, and record a single zone change in a prerecorded scene without affecting the rest of the scene. 
     In some applications, especially in public buildings, it is advantageous to be able to prevent present scenes from being erased or altered. A control panel with a key locking mechanism can limit access to scene-record actuators. In other circumstances, it is necessary to create new scenes, but desirable to retain the originals (set by the lighting designer, for example). The Omega control system includes a disk storage and recall system, which allows scenes to be stored on magnetic disks. The disks may then be kept in a separate location. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a lighting control system comprises, in combination: 
     (a) means for independently setting power levels to each of a plurality of zones of lighting, 
     (b) means, requiring no operator action, for electronically storing a plurality of combinations of said power levels, and 
     (c) means for selecting any one of said combinations of power levels. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a front view of a control panel of the present invention. 
     FIG. 2 is a drawing of a treadmill rotary encoding scheme. 
     FIG. 3 is a block diagram showing the logic structure of a control system of the present invention. 
     FIG. 4 is a memory map illustrating an embodiment of an electronic memory. 
     FIG. 5 illustrates a keyboard matrix connection. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 depicts an embodiment of a control panel of the present invention for controlling up to twenty-four zones of lighting with eight possible preset scenes. The system operates as follows: a particular combination of twenty-four zone intensity levels (i.e. a scene) is selected by pressing one of eight scene select actuators 1, preferably a momentary contact push button. Optional scene select indicator 13, preferably a light emitting diode (LED), indicates when that scene has been selected and remains lit while that scene is active. Optional scene identifiers 17, which may be attached to the inside of hinged cover 18, identify the scenes that correspond to the scene select actuators 1. Actuator 3 is a power off switch: pressing it turns power to all zones off. Power can be restored by selecting any one of the eight preset scenes. 
     New scenes are created by adjusting zone intensities to desired lighting levels. Optional zone identifiers 19 identify the zones. A zone is selected for adjustment by pressing its corresponding zone selection actuator 11, preferably a momentary contact push button. Zone intensities are then set via the zone power level control 7, preferably an endless travel thumbwheel encoder. Rotating thumbwheel 7 up or down increases or decreases the intensity of the selected zone, respectively. Although FIG. 1 shows all zone intensities adjustable by a single control 7, it is also feasible for zone intensities to be adjustable via multiple controls. 
     Preferably, more than one zone may be simultaneously selected, the light intensity of each selected zone increasing or decreasing equally by an amount proportional to the displacement of thumbwheel 7. Alternatively, the percent increase or decrease in zone intensities may be proportional to thumbwheel displacement. Zone adjustments are automatically stored in memory. 
     Zone intensity is preferably indicated by a vertically aligned array of light emitting diodes 9, in which the number of diodes consecutively lit from the bottom indicates zone intensity. Alternatively, the position of a single illuminated diode in the array may indicate zone intensity. Zone selection indicator 15, perferably an LED, lights when its corresponding zone is selected for adjustment and remains lit until the zone is deactivated; i.e., &#34;deselected&#34;. Optionally, lights in the selected zone may be flashed to physically indicate selected lights. 
     In a preferred embodiment, zones are deselected by pressing the zone selection actuator a second time. The zone selection actuator may be an alternate action push button, which, when pressed, opens a pair of closed contacts or closes a pair of open contacts. Alternatively, zones may be deselected by a time lapse after adjusting zone intensities or by selection of another zone after adjusting zone intensities. 
     When a preset scene is selected, lights in each of the twenty-four zones fade from the previous scene to the selected scene over a period of time. This fade time is preferably adjustable via optional fade adjustment potentiometer actuator 5. Alternatively, thumbwheel 7 may be adapted to adjust fade time as well as zone intensities. Preferably, all scenes have the same fade time; however, it is possible to apply separate fade times for each scene and for fade-up and fade-down, if desired. 
     Optionally, thumbwheel 7 could provide a convenient way to proportionally dim an entire scene (i.e., dim all zones in a scene proportionally). It may be enabled by default if the encoder wheel is displaced while no zones are enabled, or it may be enabled by a separate scene dim actuator (not shown). 
     Hinged cover 18 opens and closes to allow or deny access to zone selection actuators 11, thumbwheel 7, and fade adjustment actuator 5. Scene select actuators 1 remain accessible when hinged cover 18 is closed. The hinged cover may be translucent, to allow viewing of zone intensity indicators 9, or it may be opaque. 
     FIG. 2 illustrates a &#34;treadmill&#34; rotary encoder scheme which may be used in place of thumbwheel 7 to set zone intensity levels. Sliding a finger up or down the knurled surface of treadmill 20 rotates encoder wheel 22, increasing or decreasing the zone intensity level. Preferably, treadmill 20 is translucent and the LED bar graph 9, which indicates zone intensity, is visible through it, each zone being controlled by a corresponding treadmill encoder. 
     FIG. 3 depicts a block diagram of a control system of the present invention. Microprocessor 25 is the central control device, which instructs the dimming cabinet 37, executes programming functions, and operates the indicator driver 31. Operating instructions for microprocessor 25 are stored in a 32K×8 EPROM memory chip 29. 
     When zones are selected for adjustment, a microprocessor 25 reads rotary encoder 35 to detect rotation and direction of travel. It then sends a multiplexed signal to a remote dimming cabinet 37, instructing it to increase or decrease the corresponding zone power levels. Adjusted values become part of the active lighting scene and the corresponding preset scene, stored in an 8K×8 bit random access memory (RAM) chip 27. 
     Indicator driver 31 receives control information from microprocessor 25, instructing it to turn appropriate indicators on or off to indicate zone power levels and selected zones and scenes. 
     The present invention may optionally permit use of auxiliary controls 39, which may include a remotely locatable wall-mounted scene selector, a wireless remote scene selector, or a hand-held programmer, among others. Preferably, a wall-mounted auxiliary scene selector provides actuator buttons for selecting any of the preset scenes stored in RAM chip 27, and can be mounted remotely from the control system to which it is electrically connected. A wireless remote scene selector preferably provides actuator buttons for selecting any of the preset scenes and includes an infrared transmitter to send selection information to a receiver that is electrically connected to the control system. A hand-held programmer preferably includes controls necessary to set scenes (i.e. zone selection/deselection actuators, fade rate adjustment actuator, and a rotary encoder) and may be connectable to the control system via multiplex signal carrying wires. Optionally, the hand-held programmer may be a wireless remote control. Preferably, a wireless programmer includes auxiliary scene select actuators for selecting scenes to be set. 
     According to the present invention, scenes are stored in an electronic memory, which is updated after each zone adjustment. In this manner, any changes made to a preset scene are automatically stored in memory, without requiring use of additional &#34;store&#34; and &#34;recall&#34; actuators. In conjunction with an encoder wheel, this &#34;transparent&#34; electronic memory allows quick and easy adjustments to be made to any zone within a preset scene without disturbing remaining zones in the scene. 
     FIG. 4 is a memory map of the 8K×8 bit RAM 27 used to electronically store scenes. Active zone power levels are stored in a 24×8 bit &#34;active scene&#34; register 53 that is updated approximately every eighth of a second. Preset scenes are stored in an 8×24×8 bit memory array 43. 
     Upon selecting a preset scene, its corresponding 24×8 bit register 45, containing twenty-four power level settings 47, is loaded into a &#34;new scene&#34; register 49. The active scene is then faded to the new scene by repeatedly increasing or decreasing each zone power level, in the active scene register 53, by an amount proportional to the difference between the active and new zone power levels divided by the fade time. Zone power levels change during the fade time, after which the active scene register 53 is equal to the new scene register 49. All zones reach their new power levels at substantially the same time. 
     In order to protect important scenes, the present invention optionally provides for a limited access memory. Scenes stored in the limited access memory array 41, can only be accessed via a key. Alternatively, limited access array 41 may be accessible by activating a special combination of actuators. All eight scenes in the preset scene memory array 43 may be recalled and adjusted by any user, but changes will not be saved to limited access array 41 unless it has been accessed. When limited access array 41 is accessed, values stored in it are copied into the preset scene memory array 43, and subsequent changes made to preset scenes are stored in both arrays 41 and 43. 
     In a preferred embodiment of the present invention, scene and zone selection actuators are electrically connected in a keyboard matrix configuration, as illustrated in FIG. 5. Activating an actuator 65 electrically connects corresponding column conductor 67 and row conductor 69. Column driver 63 continuously sends consecutive high bits to each of its eight column conductors 67. When received by row receiver 61, the high bit indicates an activated switch, whose matrix address corresponds to the position of the sending conductor on the column driver 63 and the position of the receiving conductor on the row receiver 61. Address information is conveyed back to microprocessor 25 (see FIG. 4) via data lines 71. 
     Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted in an illustrative and not a limiting sense.