Abstract:
A lighting system suitable for chromatherapy includes a plurality of light fixtures mounted through walls of a tub basin to project different color light into the water in the tub. The light fixtures are operated by a central control unit and each includes a housing having a concave internal surface. An array of light emitting diodes that project different color light is mounted under a cap covering one end of the housing. A lens is threaded onto the opposite end of the housing from within the tub basin to secure the light fixture to the tub. The concave surface has the different color light projected on it, and reflects light out the light fixture in mixed fashion.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Not applicable. 
     STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to tubs such as bathtubs in which controllable lights are provided to illuminate the water with differing colors. 
     The presence or absence of light, and in particular colored light, is known to influence a person&#39;s mood at the time of the exposure. Over extended periods the presence or absence of such light may also have effects on physical, mental, spiritual and emotional well-being. In this regard, military personnel who are temporarily assigned to military bases near the Arctic Circle have shown marked increases in the incidence of depression during winters, absent exposure to artificial sources of light. 
     There are also those who believe that the differing frequencies of different colors may affect particular biological functions (e.g. the vibration of certain cells of the human body and thus certain biorhythmic functions) on more than a transitory basis. For example, some believe that when a human is exposed to prolonged red light that person&#39;s blood pressure will be higher even after the exposure, and the opposite will occur when the exposure is to a prolonged blue light. 
     Chromatherapy (the exposure of a human to colored light) has therefore been proposed for use to provide at least some relief for visual maladies, headaches, stress, anxiety, mental fatigue and depression. Some spas and holistic treatment centers even provide chromatherapy as a separate service or in conjunction with other treatments, such as facials, massage, acupuncture and treated baths. 
     Chromatherapy may be conducted in a room painted or illuminated with a particular color. However, another approach of increasing interest is to conduct chromatherapy by illuminating tub water with particular color or colors of light. 
     U.S. Pat. No. 885,441 discloses an early attempt at illuminating a pool with colored light, primarily for enhancing the aesthetic appearance of the pool. This early patent discloses a tank structure with slots beneath the floor in which were disposed ordinary incandescent lights mounted to removable slides located beneath glass windows in the floor of the tank. Another light was mounted over another window covered by a colored transparent film to illuminate the water with colored light. The inside surfaces of the tank were covered with luminous paint or other phosphorescent substance. 
     Small bathtubs have been devised having lighting systems for illuminating the bath water with particular color light. For example, U.S. Pat. No. 4,535,489 discloses a decorative bathtub with a transparent floor that was illuminated by white or colored light by a lamp mounted below the floor. U.S. Pat. No. 4,945,908 patent discloses a bath having multiple overhead and in-floor metal halide lamps emitting ultraviolet light rays. 
     A more recent bathtub chromatherapy system is disclosed in U.S. patent application Ser. No. 09/633,400, filed Aug. 7, 2000 and assigned to the assignee of the present invention. This application and the above mentioned patent are incorporated herein by reference as though fully set forth herein. The disclosed bathtub chromatherapy system uses a central incandescent light source and motorized color filter wheel to generate colored or white light directed to the end of a fiber optic bundle. Fiber optic cables carry the light to refractive lenses positioned at openings in the tub to illuminate the water. Desired colors can be selected and maintained or the colors can be automatically cycled. 
     While this system provides an enhanced chemotherapeutic bathing experience, it requires a rather complex motorized color wheel. Moreover, the incandescent bulb will eventually burn out and need to be replaced. This can be a problem if the tub is built into a tiled-in enclosure island with limited access to the tub bottom. 
     Thus, it can be seen that a need still exists for improved bathtub chromatherapy systems. 
     SUMMARY OF THE INVENTION 
     In one aspect the invention provides a lighting system for a tub containing a liquid. There is a first light emitting diode generating a first color light, a second light emitting diode generating a second color light, a control unit controlling the operation of the light emitting diodes, and a concave surface. The first and second light emitting diodes are positioned relative to the concave surface so as to be able to project the first and second color lights on the surface such that the surface reflects the lights in a mixed fashion. 
     In preferred forms the concave surface is on a surface of an inner bore of an elbow housing, the first and second light emitting diodes are positioned adjacent one end of the elbow housing, and a lens is positioned adjacent an opposite end of the housing. There can be even more such light emitting diodes, each of which projects light on the concave surface. In fact, there can be so many varied light colors that the mixed light can be white light when all are on, and alternatively at least one non-white light when less than all are on. 
     In other forms the light emitting diodes are positioned adjacent an inlet end of the elbow housing and the lens is attached to an outlet end of the elbow housing, and the inlet and outlet ends are perpendicular to each other. A cap is connectible to the elbow housing. The cap houses a circuit board to which the light emitting diodes are connected, and preferably also at least part of the light emitting diodes. 
     In another aspect there is also a tub with which the lighting system is used. The lens is mounted against an inner wall of the tub, and the elbow housing is mounted against an outer wall of the tub. In especially preferred forms there are a plurality of such elbow housings and lenses mounted through openings in the tub basin. For example, one unit can be mounted at the foot of the tub, and the other adjacent a back rest. 
     The system is particularly useful for chromatherapy applications such as in connection with a bathtub (e.g. especially a whirlpool). However, it may also be used for decorative purposes such as in connection with ornamental fountains. 
     The invention provides a compact light fixture operable by a control unit to selectively illuminate water in a tub with colored and/or white light. Because LEDs are used to generate the light, the light fixture is easy to maintain and requires little service. The concave reflecting surface provides an effective way of blending the colored light such that the resulting color at any given time is a single color, without striations. 
     Thus, depending on the desired effect, the water can be illuminated with soothing colors, such as pastels, or vibrant colors, such as primary colors. The light fixtures themselves are compact, light-weight and easily mountable to the tub walls without enlarging the overall dimensions of the tub. 
     These and other advantages of the invention will be apparent from the detailed description and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a bottom, right, frontal perspective view a bathtub having a chromatherapy system according to the present invention; 
     FIG. 2 is a left, upper, frontal perspective view thereof; 
     FIG. 3 is a side view of a light fixture of the chromatherapy system; 
     FIG. 4 is an exploded view of the light fixture of FIG. 3; and 
     FIG. 5 is a bottom plan view of an upper part of the FIG. 3 light fixture; 
     FIG. 6 is a sectional view taken along line  6 — 6  of FIG. 5; and 
     FIG. 7 is a vertical sectional view of the FIG. 3 light fixture. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A preferred embodiment of the present invention is a bathtub with a chromatherapy system referred to generally by numeral  10 . The bathtub shown in FIG. 1 is a whirlpool overflowing soaker tub of the type described in more detail in the aforementioned application incorporated by reference. However, the chromatherapy system of the present invention can work with a wide variety of tubs that contain water, regardless of whether used for bathing, and regardless of whether having whirlpool features. Examples could include whirlpool bathtubs, more conventional bathtubs, spa tubs, swimming pools, and pools around ornamental fountains. 
     In accordance with the preferred form of the invention, two light fixtures  12  are mounted through openings in a foot end wall  14  of the tub basin  16  and two such fixtures are mounted through openings in the back rest  18 . Preferably, the openings are near the bottom of the tub basin. 
     The light fixtures  12  are electrically connected by wires  20  to a central controller unit  22  (see FIG. 7) that is preferably mounted to the underside of the tub. The control unit  22  has circuitry for controlling the operation of the light fixtures  12  as will be described below. 
     As will be best appreciated from FIGS. 3,  4  and  7 , each light fixture  12  may be identical and includes an L-shaped tubular body or elbow  24 , preferably a PVC pipe made of Cycolac® 5500 or 5600 ABS. A flared end  26  of the elbow  24  has internal threads that engage a cylindrical base end  28  of a refractive lens  30 , preferably made of a translucent polycarbonate material. The lens  30  has a diffuser plate  32  with a diameter larger than the opening  34  in the tub basin  16  and abuts the inside of the tub when the cylindrical end  28  of the lens  30  is disposed in the opening  34 . The lens  30  (and thus the light fixture  12 ) is secured to the tub basin  16  by a nut  36  (with grip features  37 ) that threads onto the cylindrical end  28  of the lens  30  and abuts the outside of the tub. A rubber gasket  38  is disposed between the tub and the nut  36  to create a water-tight seal at the opening  34 . 
     The other end  40  of the elbow  24  has two catches  42  extending outwardly from opposite sides of the elbow  24 . The catches  42  taper outwardly from the curved exterior surface of the elbow  24  to define a ledge  44  nearly perpendicular to the elbow  24 . Between the two catches  42  is a locator recess  46  at the top edge of the elbow  24  opening outward. 
     The catches  42  allow a cap  48  to be snapped onto the elbow  24  by engaging square openings  50  in downwardly depending fingers  52 . The tapered surfaces of the catches  42  ease the fingers  52  outward so that the openings  50  engage the ledges  44  to secure the cap  48  to the elbow  24 . The cap  48  can be removed by prying the fingers  52  outward past the ledges  44 , for example with a flat screw driver. 
     The cap  48  is preferably made of the same material as the elbow  24  and is generally cylindrical with a circular top wall  54 . The cap  48  has four vents  56  projecting radially outward from the cylindrical wall so that air can pass into and out of the cap  48  when it is mounted on the elbow  24 . The vents  56  open downwardly so that water cannot spill directly into the cap  48 . The vents  56  allow air to circulate through the cap  48  and dry up any humidity or moisture present inside. 
     As seen in FIGS. 5 and 6, the inside of the cap  48  has four vertical mounts spaced apart ninety degrees and extending in the direction of the centerline of the cap  48 . Mounts  58 ,  60  and  62  are identical and define ledges  59 ,  61  and  63 , respectively. Mount  64  is similar but thicker and defines ledge  65 . A locator rib  66  is formed adjacent mount  60  and is sized to fit into the locator recess  46  of the elbow, and thereby fix the orientation of the cap  48  to the elbow  24 . 
     The mounts  58 ,  60 ,  62  and  64  retain a circular circuit board  68  which has four notches  70 ,  72 ,  74  and  76  corresponding to the mounts. The circuit board  68  is secured to the ledges  59 ,  61 ,  63  and  65  with an epoxy and is maintained parallel to the top wall  54  of the cap  48 . 
     As seen in FIG. 7, the circuit board  68  is linked to an array of light emitting diodes (LEDs)  78 . Preferably, there are nine LEDs  78 ; three red, two blue, two green and two amber. The outer ring of LEDs  78  are mounted to the circuit board at an inward angle so that their individual light rays converge. 
     The position of the LEDs  78  and the orientation and position of the circuit board  68  is designed to direct the light rays of each LED to a region  80  at the inner surface of the elbow  24 . More specifically, the region  80  is a concave surface at the bend in the elbow  24  that reflects light through the elbow  24  and the lens  30 . Preferably, this region  80  is less than ½ inch. The entire inside surface of the elbow  24  has a SPE #1 finish and thus a high index of reflection. 
     Converging the light rays in this way allows them to mix before being reflected through the lens  80 . This blends two or more different color light rays so that a single color is passed through the lens  30 . Thus, individual light rays are not separately visible through the lens  30  (e.g. there are no shadows of odd colors). The net result is a single diffused color light even when different colored LEDs are illuminated simultaneously. 
     In the preferred embodiment, the nine LED array with four different colors (red, blue, green and amber) can produce eight distinct colors (lavender, blue, light blue, green, yellow, orange, red and white) depending on which LEDs are activated by the controller. It should be noted that other or additional colors could be generated with a chromatherapy system of the present invention by using a larger or different color combination LED array or by varying the intensity of one or more of the LEDs. 
     The control unit  22  includes a microprocessor that operates various transistors to turn on one or more of the LEDs  78  as needed to generate the desired color. For example, the green LEDs  78  are energized to produce green light and the red and blue LEDs  78  are energized to produce lavender light. All nine of the LEDs  78  are energized to produce white light. 
     In the disclosed embodiment, the control unit  22  is a peripheral to a motor controller  82  (see FIG. 1) operating the water jet system. It should be noted, however, that the control unit  22  could stand alone without the motor controller to provide a chromatherapy system for a conventional non-whirlpool bathtub. 
     Referring to FIG. 7, the control unit  22  is connected to the motor controller  82  and a power supply  83  in addition to the light fixtures  12 . Preferably, the light fixtures  12  are connected together in a “daisy chain” with the wire from one light fixture connecting to the circuit board of the next light fixture through opening  84  in the top wall of its cap. Another wire then leads from the circuit board of this light fixture out opening  86  in the top of its cap to the next light fixture. Thus, only one cord runs into the control unit  22  from the light fixtures  12 . In this arrangement, the LEDs of each light fixture  12  are energized the same so that the same color light is produced by all light fixtures  12 . 
     The chromatherapy system can be activated and operated by a user sitting in the tub basin via a button  88 , preferably a piezoelectric push button, at the deck surrounding the basin that is electrically coupled to the control unit  22  through the motor controller  82 . The control unit  22  can be programmed so that the first time the button  88  is depressed all of the LEDs in each of the four light fixtures  12  will be energized, which produces a white light through each lens  30 . The white light is sustained for approximately four seconds after which the controller sequences through each color, sustaining each for about eight seconds. When a desired color is illuminated, pressing the button  88  again will sustain the color indefinitely. 
     Pressing the button  88  again when the control unit  22  is out of the sequencing mode will shut off power to the light fixtures  12 . Pressing the button  88  again will restore power to the light fixtures  12  which will illuminate the last sustained color. 
     The present invention thus provides a chromatherapy system for illuminating bath water with white or colored light to enhance the bathing experience. The light fixtures themselves are compact, light-weight and easily mountable to the tub walls. Since the light sources are generated from LEDs, they run much cooler than incandescent bulbs, and last much longer without replacement or service. The LED array can be constructed and controlled to emit a variety of colors without striations. All lights can be controlled while soaking in the tub by simply depressing one switch. Moreover, a system is provided to mix the lights, regardless of which light combination is chosen. 
     A preferred embodiment of the invention has been described in detail. However, the invention may be applied in a variety of other embodiments which are within the scope of the invention. For example, the system may only have red and blue LEDs. Thus, to ascertain the full scope of the invention, the following claims should be referenced. 
     INDUSTRIAL APPLICABILITY 
     The invention provides a chromatherapy system for bathtubs.