Abstract:
An apparatus and method for our artificial aquarium featuring artificial creatures, such as fish, behaving in a life-like manner. A tank is equipped with electromagnets which create magnetic fields which act on magnets within the artificial fishes&#39; bodies, causing them to move. The tank&#39;s electromagnets are activated by a programmable logic controller (PLC). Input devices placed in the tank may send signals to the PLC, causing the activation or deactivation of certain electromagnets which affects the movements of the fish. Water flow from a water pump may also cause the artificial fishes to move.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to artificial aquaria, especially those with artificial aquatic creatures.  
         BACKGROUND OF THE INVENTION  
         [0002]    Aquaria are popular fixtures in homes and offices as well as other public venues, such as hotels and restaurants. In addition to providing an impressive display of fish and other marine life such as invertebrates, coral, and/or plants, aquaria are also valued for their soothing effect on observers.  
           [0003]    Although the benefits of an aquarium are great, large amounts of time and money are required to set up and maintain an aquarium. In addition to buying the equipment necessary to set up an aquarium (at minimum, a tank, gravel or sand, filters, heaters, and animals), cleaning, feeding, and restocking an aquarium require time and money as well as a certain level of expertise to ensure that the water quality (salinity, pH, nitrite levels, temperature, etc.) is acceptable, the tank&#39;s inhabitants are receiving the correct diet, and the tank&#39;s occupants can peacefully coexist. “Catastrophic” events, such as disease, tank leaks, or power failures which disable filters and heaters, can kill off all tank inhabitants; these events are not uncommon and may occur regardless of the aquarist&#39;s experience and precautions to ensure these events do not happen.  
           [0004]    There are also environmental concerns associated with keeping aquariums, particularly saltwater tanks. In addition to the threat posed by pollution, coral reefs are also endangered because both the coral and reef life are “harvested” to provide material for aquariums. Many species of fish and other marine life which cannot exist in captivity (generally because of issues related to the animal&#39;s food supply) are captured and sold to unsuspecting aquarists. Furthermore, most marine species do not breed in captivity, so the demand for marine creatures that are caught in their natural habitat is likely to continue unabated.  
           [0005]    In addition, “biological pollution” from escaped aquaria organisms poses an even greater potential hazard. For example, an algae believed to have been introduced into coastal waters by disposal of tank water into a municipal water disposal threatens to overwhelm and displace native algae in the Mediterranean and California, perhaps irreversibly altering these ecosystems.  
           [0006]    Some reefs are now being designated as “no-take” ecological reserves, meaning that the removal of any marine organism from a protected reef is prohibited. While protection for reefs is welcome from an environmental point of view, it is likely that the cost of fish, coral, and other marine organisms taken from unprotected reefs will increase as a result of this protection. Consequently, the cost of keeping a marine aquarium will also increase.  
           [0007]    Given these problems, an artificial aquarium is an attractive proposition to those who wish to enjoy the benefits of an aquarium without the drawbacks of aquarium ownership and maintenance. The prior art contains several examples of artificial aquaria.  
           [0008]    U.S. Pat. No. 4,578,044 discloses a toy aquarium containing a toy fish having an interior magnet and a base with a permanent magnet. A magnetic coil in the base generates magnetic force; a change in the polarity of lines of this magnetic force causes the permanent magnet to move. The movement of the permanent magnet is transmitted to the toy fish by means tethering the toy fish to the base.  
           [0009]    U.S. Pat. No. 4,691,459 discloses an artificial aquarium with a whirlpool pump which causes circular movement of the water in the aquarium tank. This circular movement causes weighted toy fish in the aquarium to move. A baffle prevents the toy fish from being sucked into the whirlpool pump.  
           [0010]    U.S. Pat. Nos. 5,301,444; 5,463,826, and 5,685,096 are artificial aquaria containing artificial fish with magnets. Rotating magnets generate magnetic fields at different speeds, causing the fish to move around.  
           [0011]    U.S. Pat. No. 6,148,770 discloses an artificial aquarium with ornamental features (artificial jellyfish, for instance) which move in response to a changing magnetic field created by magnets in the base. The ornamental features have magnets and are weighted or otherwise secured so they do not float to the top.  
           [0012]    None of the prior art discussed here discloses an artificial aquarium where the artificial fish display realistic behavior (eating, fighting, etc.). It is an object of this invention to provide a mechanism that enables artificial fish to simulate realistic behavior.  
           [0013]    None of the prior art discussed here discloses an artificial aquarium that employs both waterflow and magnetic fields to make artificial fish move.  
         SUMMARY OF THE INVENTION  
         [0014]    An artificial aquarium is stocked with artificial aquatic creatures, such as fish, as well as artificial rocks and corals to provide a realistic simulation of a fish tank with live creatures. Each of the artificial creatures has a slight negative buoyancy when submerged in water. Additionally, the creatures each have magnets encased within their bodies.  
           [0015]    There are two mechanisms which cause the creatures to move around the tank: water flow and magnetic fields. One or more water pumps circulate water in the tank, creating a “current” which causes the artificial creatures to move around the tank as if they were swimming. In addition to the water pump, a number of electromagnets are placed around the tank, some in a central column in the tank, others within artificial rocks and coral. A programmable logic controller controls the activation of the electromagnets. The fields generated by these electromagnets attract and repulse the artificial creatures. The artificial creatures move in a life-like manner due to the movement created by the combination of the magnetic fields and the water flow within the tank.  
           [0016]    Realistic behavior, such as feeding and hiding, can also be simulated. As noted above, the activation of the electromagnets is controlled by a programmable logic controller. Inputs to the logic controller, such as optical sensors placed around the tank, can cause the controller to either activate or deactivate the electromagnets placed around the tank. For instance, if an optical sensor placed near one of the artificial corals detects an artificial creature passing by, it can signal the programmable logic controller which in turn activates the electromagnet within the artificial coral. The activated electromagnet attracts the magnet embedded within the creature. As a result of this attraction, the creature appears to be feeding on the coral. The logic controller can deactivate the magnet after a certain period of time, causing the creature to move away from the coral as it drifts with the flow. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a view of an artificial aquarium in accordance with the invention.  
         [0018]    [0018]FIG. 2 is an overhead view of the tank and some components used in the artificial aquarium shown in FIG. 1.  
         [0019]    [0019]FIG. 3 is an exploded view of the tank and components of the artificial aquarium shown in FIG. 1.  
         [0020]    [0020]FIG. 4 is a partial cut-away view of the artificial aquarium shown in FIG. 1.  
         [0021]    [0021]FIG. 5 is a cut-away view of the artificial aquarium shown in FIG. 1.  
         [0022]    [0022]FIG. 6 a  is a view of an artificial fish used in the artificial aquarium shown in FIG. 1.  
         [0023]    [0023]FIG. 6 b  is a sectional view of the artificial fish shown in FIG. 6 a.    
         [0024]    [0024]FIG. 7 is an overhead view of the power supplies and programmable logic controllers used in the artificial aquarium shown in FIG. 1.  
         [0025]    [0025]FIG. 8 is a side view of the tank and some components used in the artificial aquarium shown in FIG. 1.  
         [0026]    [0026]FIG. 9 is an exposed view of the top assembly of the artificial aquarium shown in FIG. 1.  
         [0027]    [0027]FIG. 10 is a view of the central column of the artificial aquarium shown in FIG. 1.  
         [0028]    [0028]FIG. 11 is a view of the bottom assembly of the artificial aquarium shown in FIG. 1.  
         [0029]    [0029]FIG. 12 a  is an isolated view of one example of the rear wall of the tank of the artificial aquarium showed in FIG. 1.  
         [0030]    [0030]FIG. 12 b  is a view of the tank with the rear wall shown in FIG. 12 a.    
         [0031]    [0031]FIG. 13 a  is a view of a backdrop to be attached to the back of the tank of one embodiment of the artificial aquarium shown in FIG. 1.  
         [0032]    [0032]FIG. 13 b  is a view of the tank with the attached backdrop shown in FIG. 13 a.    
         [0033]    [0033]FIG. 13 c  is a side view of the tank with the attached backdrop shown in FIG. 13 a.   
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0034]    With respect to FIG. 1, the artificial aquarium of the invention includes a fish tank  10  with a top assembly, or lid  14 . The tank  10  can rest on a stand  12  (as shown in FIG. 5, the stand can also be used for storage). The tank is equipped with a water pump  16 , decorative objects  18 , including artificial rocks, coral, or plants, artificial aquatic creatures  22 , including fish, and a waterproof casing  20  covering a central column located toward the back of the tank. In this embodiment, the tank  10  has a half-cylindrical front to promote laminar flow of water within the tank  10 ; this assists the fish  22  to move freely throughout the tank  10  and not become trapped in one area of the tank  10 . The tank  10  may have a different shape in other embodiments.  
         [0035]    In FIG. 2, the tank  10  is shown in greater detail. The central column casing  20  is a decorative, waterproof shield which protects a central column  30  containing electromagnets  24  and optical sensors  26  (the operations of the electromagnets  24  and sensors  26  will be discussed in greater detail below in FIG. 5; the central column  30  may contain variously-sized and strategically-placed electromagnets  24 ). The bottom  28  of the tank is concave to promote water flow (see FIG. 11). Although the water pump  16  shown here is attached to the bottom  28  of the tank  10 , in other embodiments the water pump may be located anywhere in the tank  10 . The water pump  16  may be exposed or hidden from view (i.e., underneath gravel).  
         [0036]    An exploded view of the tank assembly  34  is shown in FIG. 3. The tank  10  portion of the assembly  34  includes: the glass or acrylic walls  32 ; the bottom of the tank  28 ; the water pump  16 ; the central column  30 ; the central column casing  20 ; assorted electromagnets  24  to be attached to the central column  30 ; and assorted sensors  26 , also to be attached to the central column  30 . The lid, or top assembly,  14  includes the following: a bottom casing  36  for the lid assembly; a lighting system, in this embodiment a socket  86  and lightbulb  58 , which is affixed to the bottom casing  36 ; a programmable logic controller/power supply casing  38 ; two power supplies  40 ; a programmable logic controller (PLC)  42 ; feed-thrus  48  for passing electrical wires between the central column  30  and the lid  14 ; cap feed-thrus  46  for guiding the wires; and a top casing  44  of the lid  14 . The top assembly  14  is watertight. The electronics assembly, the PLC  42 , power supplies  40 , and associated wiring, etc. may be stored somewhere else (for example, the bottom of the tank  10  or in storage beneath the tank  10 ) in another embodiment.  
         [0037]    With respect to FIG. 4, the assembled tank assembly  34  is shown. The cutaway portion of the figure shows the central column casing  20 , the central column  30 , and the top lid assembly  14  with the power supplies  40  and programmable logic controller  42  within their casing  38 .  
         [0038]    As shown in FIG. 5, the tank is decorated with artificial rocks or coral  18 . The corals  18  contain electromagnets  24 , controlled by the programmable logic controller  42 , and may also contain input devices such as optical sensors  26 , which transmit information to the PLC  42 . The artificial corals  18  are covered in a waterproof casing. (As noted above in FIG. 2, optical sensors  26  may also be contained in the central column  30 .) Information or commands sent by or to the PLC  42  by the electromagnets  24  or the sensors  26  is relayed by wires  62 . Activated electromagnets  24  in the coral  18  and central column  30  generate magnetic fields  50 . The water pump  16 , which along with the corals  18  may be surrounded by gravel, sand, or artificial crushed coral  52  covering the bottom of the tank, continually takes in water  56 , thus recycling the water in the tank and creating a water flow  54 . The magnetic fields  50 , combined with the water flow  54  generated by the water pump  16  combine to act on the fish  22  (described in greater detail below in FIGS. 6 a  and  6   b ) in the tank, with the result that they move about the tank in a lifelike manner.  
         [0039]    An example of the artificial fish  22  used in the aquarium is illustrated in FIGS. 6 a  and  6   b.  An intact fish  22  is shown in FIG. 6 a.  The fish  22  are modeled on real marine or fresh water fish and constructed of plastic, fiberglass, or similar material. In this embodiment, the fish may have silicone skins to enhance their life-like appearance and reduce or eliminate any sound which might occur if a fish  22  swims into a tank wall. As shown in FIG. 6 b,  the fish  22  contains an earth magnet  64  and sufficient ballast  66  to ensure the fish has slightly negative buoyancy when submerged in water. The fish  22  in this embodiment is covered in a silicone skin  104 . The two halves of the fish  22  are fastened together by pins  68 . A tail piece  88  is also attached. In other embodiments, the magnets  64 , ballast  66 , and pins  68  may be located in different positions and the tail piece  88  may not be detached from the body.  
         [0040]    Referring again to FIG. 5, the water flow  54  causes the fish  22  to move about the tank. The magnetic fields  50  generated by the electromagnets  24  also effect movement in the fish  22 . The fish  22 , which as noted above contain a magnet, are attracted or repelled by the magnetic fields  50 . Electromagnets  24  may be used to induce simulated behavior in the fish  22 . For example, feeding behavior, such as nibbling on corals, can be simulated by using the sensors  26  and electromagnets  24 . As noted above, the aquarium contains a lighting system  58 . Optical sensors  26  can be placed throughout the tank, in this case, on coral  18 , to monitor light beams  60 . If a fish  22 A swims through a beam  60  and interrupts the light flow to the sensor  26 , the sensor  26  can signal the PLC  42 , which in turn can activate a nearby electromagnet  24 A. The resulting magnetic field  50  attracts the nearby fish  22 A to the coral  18 . The PLC  42  can turn off the electromagnet  24 A after a predetermined period of time, releasing the fish  22 A. This entire sequence simulates a fish&#39;s  22 A feeding behavior, i.e., nibbling on coral  18  for a period of time and then swimming away. Other behaviors, such as schooling together or hiding, can be simulated in similar fashion.  
         [0041]    The power supplies  40  and PLC  42  are shown in FIG. 7. In this embodiment, there are two power supplies  40  to run the aquarium&#39;s lighting, electromagnets, sensors, pumps, PLC  42 , etc. The power supplies  40  are standard 12-24 volt supplies with built-in transformers. The PLC  42  is also standard and receives input from the sensors, as described above in FIG. 5, and sends commands to the electromagnets in the aquarium, also described in FIG. 5. The power supplies  40  and the PLC are shown within a casing  38  that is watertight. All of the electronic assembly complies with NEMA, UL, FCC, CE, and NEC requirements.  
         [0042]    Another view of the tank  10  and the central column  30  are presented in FIG. 8. The bottom of the lid assembly  36  is presented without the electronic assembly discussed above in FIG. 3. In this embodiment, the water pump  16  is attached to the bottom surface of the tank  28 , but it may be placed elsewhere in the tank. The central column  30  contains a variety of electromagnets  24  as well as optical sensors  26 ; the electromagnets  24  and sensors  26  may be placed in different locations on the central column  30 .  
         [0043]    With respect to FIG. 9, the bottom of the lid assembly  36  containing portions of the invention&#39;s electronics assembly is shown in detail. Wires (see FIG. 5) connecting the power supply  40  and PLC  42  with electromagnets, sensors, the water pump, etc. within the tank are passed through feed thrus  48 . The feed thrus  48  have caps  46  for guiding the wires. As noted above, the power supplies  40  and PLC  70  are contained in a watertight enclosure  38 . The PLC is configured to receive input  72  from sensors in the tank and send output  70  to devices such as the water pump and electromagnets.  
         [0044]    The central column  30  is detailed in FIG. 10. In this embodiment, the column  30  is semi-cylindrical, having a top, bottom, and five sides, four of which contain magnets  24  and sensors  26 . The bottom of the column has a pin  78  to fasten it to the bottom surface of the tank. The four sides of the column  30  which contain magnets  24  and sensors  26  have holes  74  for mounting the magnets  24  and sensors  26 . The holes  74  in the column  30  allow wires to pass from the magnets  24  and sensors  26  to the power supplies and PLC. The column may be shaped differently in other embodiments.  
         [0045]    With respect to FIG. 11, the bottom surface of the tank  28  has a concave section  80  to improve water circulation. The bottom surface  28  also features a platform  82  for mounting the central column. The platform  82  has a fastening device  76  for holding the central column in place on the platform  82 .  
         [0046]    With reference to FIG. 12 a,  in some embodiments of the aquarium the back wall  90  of the tank can contain decoration  92  such as artificial coral, rock, or plants. As shown in FIG. 12 b,  the use of this special wall  90  adds a further decorative effect to the tank  10 . The decoration  92  may be placed at various points in the wall  90  in different embodiments.  
         [0047]    Some embodiments of the aquarium can also feature a backdrop  94  for the tank that also features decoration  96  such as artificial coral, rock, or plants, as shown in FIG. 13 a.  This backdrop can be bowed, and in some embodiments the bow in the backdrop will match the curvature of the front panel of the tank. As shown in FIG. 13 b,  the backdrop  94  with the decoration  96  attaches to the back of the tank  10 . Because the backdrop  94  is bowed, it adds an extra element of depth to the tank  10 .  
         [0048]    As shown in FIG. 13 c,  the backdrop  94  may be attached to the back of the tank  10  by clips  102 . A lighting system  98  may be employed behind the tank  10  to further illuminate the decoration  96  on the backdrop  94 .