Soft light fixture

The present invention is a soft light fixture. In particular, it is an LED soft light fixture. The preferred embodiment of the soft light fixture has a plurality of light emitting diodes mounted on a perimeter ring aimed to emit light into a light-mixing chamber. The perimeter ring supports a light deflection cap with a lens, preferably translucent. The ring, deflection cap and lens define the light mixing chamber which blends light from the plurality of light emitting diodes into a single light source.

TECHNICAL FIELD

The present invention is a soft light fixture. In particular, it is an LED soft light fixture.

BACKGROUND ART

Generally, various light fixtures that use light from a combination of light sources are known including U.S. Pat. Nos. 4,280,171, 4,831,755, and 6,149,283.

Often, prior art devices that rely on the light from a combination of light sources show “hot spots.” In particular, prior art light fixtures using light emitting diodes (“LEDs”) use a large number of LEDs to generate the desired amount and color of light. However, typically, the points at which each individual LED are mounted are usually markedly visible as “hot spots” rather than the light of all the LEDs blending together to form a uniform glow.

Thus, a light fixture that uses a minimum of LEDs to generate a single light source without “hot spots” is desired. Moreover, a light fixture that blends light from different color LEDs into a single blended light source, e.g. of a new color, is desirable as well.

SUMMARY OF THE INVENTION

The present invention is a soft light fixture. In particular, it is an LED soft light fixture. The preferred embodiment of the soft light fixture has a plurality of light emitting diodes mounted on a printed circuit board ring and seated on a perimeter ring. The LEDs are aimed to emit light into a light mixing chamber. The perimeter ring supports a light deflection cap with a lens, preferably translucent. The perimeter ring, deflection cap and lens define the light mixing chamber which blends light from the plurality of light emitting diodes into a single light source. The lens preferably has a skirt that contains the printed circuit board ring, perimeter ring, and deflection cap.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[2] Referring now toFIG. 1a, an exploded perspective view of a preferred embodiment of a soft light fixture10is shown. The soft light fixture10preferably comprises a perimeter ring20having a plurality of notches22for lights. A preferred embodiment of the ring20is shown inFIGS. 2a,2band2c. There are nine (9) notches22shown inFIG. 2c. Returning toFIG. 1a, a number of lights25, preferably light emitting diodes (LEDs), are mounted on a printed circuit board (PCB) ring60. The PCB ring60is preferably flexible and has two leads65for connection to a power source (not shown.) Each LED25in turn is seated in a corresponding notch22on the perimeter ring20. Alternatively, each LED can be hard-wired to the fixture10instead of using a PCB ring.

[3] Preferably, each PCB ring60has a separate circuit for different sets of LEDs. For example, inFIG. 7, the PCB ring60has three separate circuits61,62and63. As shown, each circuit controls three LEDs. This allows different sets of LEDs to be used together. For example, this allows a mix of different voltage LEDs. White, blue and green LEDs commonly need 3.5 volts and red, amber and yellow commonly need 2.5 volts. The separate circuits can also vary the LEDs' intensity and, thus, vary the color and intensity emitted by the light fixture10.

[4] By using separate circuits on the PCB ring60, the PCB ring can have a set of leads65for each circuit. Thus, each circuit and set of LEDs can be controlled separately, e.g. dimming or powered higher using a simple dimmer or more sophisticated DMX controller.

[5] The perimeter ring20supports a deflection ring30. The perimeter ring20and deflection ring30are preferably made of white polycarbonate plastic. Referring toFIG. 2c, the perimeter ring20has an interior diameter25that is less than the diameter of the perimeter ring20. The progression from the diameter of the perimeter ring20to the interior diameter25shown inFIG. 2bis a perimeter slope29. Preferably, an angle (alpha prime, α′) is formed between the perimeter slope20and the interior diameter25. The angle α′ is preferably forty-five degrees (45°).

[6] The perimeter ring20preferably has at least one post27. Referring now toFIGS. 3aand3b, a preferred embodiment of the deflection ring or cap is shown.FIG. 3bshows a cross-section of a preferred embodiment of the deflection ring30. The deflection cap30preferably has at least one post port33that receives a post27on the perimeter ring20. The deflection ring30mounted on the perimeter ring20defines a light-mixing chamber. The deflection ring30further comprises notches32that align with the notches22on the perimeter ring20to define light ports for seating lights25, e.g. LEDs. Each light25is preferably aimed to cast light into the light mixing chamber.

[7] A lens40tops the deflection ring30. As shown inFIGS. 1a,4aand4b, the lens40can have a skirt45extending down to contain the perimeter ring20and deflection ring30. Preferably, the skirt45comprises tabs47arrange along an edge of the skirt45. Alternately, the tabs47can be located on the perimeter ring20. Regardless of their location, the tabs47are generally used to assist in assembling the fixture and/or waterproofing the fixture. Alternatively, one of the lenses40, shown inFIGS. 4cand4d, can be mounted on the deflection ring30. The lens40can be flat as shown inFIG. 4cor concave/convex as shown inFIG. 4d. Preferably, the lens40is made of translucent white polycarbonate or translucent white acrylic plastic.

[8] As shown inFIG. 1a, a fastener ring50with fastener ports55can be used to hold the lens40together with the deflection ring30and perimeter ring20or mount the fixture10to a surface, e.g. a wall, chair, or floor.FIGS. 1b,4aand4bshow an alternative embodiment of the lens40with a flange49. The flange49can be used to mount the fixture10to other external fixture housings.

[9] Referring toFIGS. 3aand3b, the deflection ring30has an interior diameter35that is less than the diameter of the perimeter ring20. Preferably, the deflection ring's interior surface slopes to the interior diameter35. This progression to the interior diameter35creates a deflection slope39that deflects light from the LEDs25into the light mixing chamber. Preferably, the deflection slope39extended forms an angle (alpha, α) at least 135 degrees from a top diameter34of the deflection ring30.

[10] Conversely, the interior diameter35is less than a lower diameter37. This progression from the lower diameter37to the interior diameter35shown inFIG. 3bis notch slope31. Preferably, the notch slope31extended forms an angle (beta, β) of 135° from the lower diameter37of the deflection ring30. Thus, the LEDs25are generally obscured from direct view by the slope39of the deflection ring30. Instead, the light from the LEDs is reflected into the light-mixing chamber defined by the above-described components to produce a soft light visible to a viewer without “hot spots.”

[11] It should be noted that the present invention generates consistent lighting out to the outer edge of the fixture10. The fixture10, in general, does not have, what is commonly called a “trim ring,” namely a dark ring along the edge of the lens40. Thus, the fastener ring50is not used to hide a dark ring at the edge of the lens40but, instead, is used for mounting purposes and other reasons described above.

[12] Referring now toFIGS. 5a–5c, this invention10provides a soft light of an intensity useful in a number of applications.FIGS. 5a–5cshow graphs of beam spread and intensity as functions of distance from the fixture10. Referring toFIG. 6, preferably, the LEDs are 20–40 milliamps (ma) light emitting diodes. If white light is desired, then only white LEDs are mounted in the notches22defined by the perimeter and deflection rings. Alternately, using a combination of colored LEDs mounted in the notches22can create soft lighting with a variety of colors. For example, if a “pink-ish” light is desired, six red LEDs and three white LEDs could be mounted on the PCB ring60in order to cast a pink-ish light from the device10. Another alternative is to color the lens40the desired color or use a colored gel with the fixture10.

[13] One preferred embodiment of the invention as described above uses three sets of three LEDs. Thus, combinations of LEDs are preferably based on multiples of three, e.g. three red LEDs and six white LEDs or six red LEDs and three white LEDs. The different circuits on the PCB ring60can also vary the color of light emitted by the fixture10. For example, two sets of three LEDs could run at 20 milliamps while a third set runs at 40 milliamps. The resistors for each circuit could also be changed to vary the power, brightness and intensity of the LEDs as well.

[14] The present invention provides an improved color consistency over the prior art as well. Typically, when dies of LEDs are produced, the LEDs are sorted into bins by a number of criteria including a large range of “acceptable” colors, or wavelengths, intensity and forward voltage. The LEDs, depending on tolerance for color variation, can be sorted several more times to isolated colors within ranges of 1–3 nanometers in wavelength. However, isolating LEDs of a color with 1 nanometer of wavelength can be very expensive. The present invention allows LEDs of a wider variation in wavelength to be used and their light mixed to produce a single color light and thus hide slight variations in color between LEDs.

[15] Thus, a soft light fixture is described above that uses a minimum of LEDs to generate a single light source without “hot spots” is described. Moreover, a light fixture that blends light from different color LEDs into a single blended light source of a new color is described as well. In each of the above embodiments, the different positions and structures of the present invention are described separately in each of the embodiments. However, it is the full intention of the inventors of the present invention that the separate aspects of each embodiment described herein may be combined with the other embodiments described herein. Those skilled in the art will appreciate that adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.