Patent Application
20140146531
The present disclosure is generally directed toward light emitting devices.
Light Emitting Diodes (LEDs) have many advantages over conventional light sources, such as incandescent, halogen and fluorescent lamps. These advantages include longer operating life, lower power consumption, and smaller size. Consequently, conventional light sources are increasingly being replaced with LEDs in traditional lighting applications. As an example, LEDs are currently being used in flashlights, camera flashes, traffic signal lights, automotive taillights and display devices. LEDs have also gained favor in residential, industrial, and retail lighting applications.
Most existing lighting fixtures or illumination devices produce spotty light when using discrete LED components as the light source. Spotty lighting is especially prevalent at the mid- or lower-brightness products such as down lighting, tube lighting, and the like. The current solution to minimize the spotty lighting is to place a cover that diffuses/disperses light over the LED components. Unfortunately, these covers further decrease the brightness of the illumination device because the cover is designed to absorb a certain amount of light.
Another solution currently employed to address the spotty lighting issue is to increase the number of LEDs and/or using smaller and lower-power LEDs. This solution is problematic in that it significantly increases the cost of the illumination device and it is not feasible in many situations where there is limited space for LED installation.
It is, therefore, one aspect of the present disclosure to provide an illumination device that overcomes the above-noted shortcomings. In particular, embodiments of the present disclosure introduce an illumination device that reduces and/or eliminates the spotty lighting problem while simultaneously enhancing the overall lighting luminaire brightness. In some embodiments, an illumination device is disclosed that includes a first light source or first plurality of light sources as well as a second light source. The first light source, in some embodiments, corresponds to one or more discrete LED components that are configured for either thru-hole mounting or surface mounting to a Printed Circuit Board (PCB) or the like. The second light source, in some embodiments, corresponds to a sheet or film-type light source. Even more particularly, the second light source may correspond to one or more flexible Organic LED (OLED) sheets. By utilizing the sheet or film-type light source in combination with the discrete light sources, embodiments of the present disclosure enable the illumination device to maintain a desired brightness without requiring more discrete light sources and still eliminating the spotty lighting issue.
The second light source, as noted above, may correspond to an OLED or set of OLEDs. In some embodiments, the OLED(s) comprise an emissive electroluminescent layer in the form of a thin and flexible film of organic compound, which emits light in response to an electric current being supplied thereto. This layer of organic semiconductor material is situated between two electrodes. Generally, at least one of these electrodes is transparent. In some embodiments, the second light source may correspond to either an OLED that is based on small molecules or an OLED that employs polymers. Adding mobile ions to an OLED creates a light-emitting electrochemical cell, which has a slightly different mode of operation. The OLED flexible film may or may not include a passive-matrix (PMOLED) or active-matrix (AMOLED).
In some embodiments, the second light source may comprise a transparent OLED sheet, that allows light emitted by the first light source(s) to pass therethrough. Meanwhile, the OLED sheet is also configured to emit light. Accordingly, the overall light output of the illumination device will correspond to the light output of the first light source(s) as well as the light output of the OLED sheet(s). The OLED(s), in some embodiments, helps reduce the spottiness of the discrete first light source(s).
The present disclosure will be further understood from the drawings and the following detailed description. Although this description sets forth specific details, it is understood that certain embodiments of the invention may be practiced without these specific details. It is also understood that in some instances, well-known circuits, components and techniques have not been shown in detail in order to avoid obscuring the understanding of the invention.
The present disclosure is described in conjunction with the appended figures:
The ensuing description provides embodiments only, and is not intended to limit the scope, applicability, or configuration of the claims. Rather, the ensuing description will provide those skilled in the art with an enabling description for implementing the described embodiments. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the appended claims.
With reference now to
Additionally, although four first light sources 108 are depicted in the image of
One commonality shared between the first light sources 108, assuming there is more than one, is that the first light sources 108 may generally correspond to discrete light sources. Examples of suitable first light sources 108 include, without limitation, surface mount LEDs, thru-hole mount LEDs, laser diodes, a cluster of LEDs (e.g., a cluster of RGB LEDs), Ultraviolet LEDs, Infrared LEDs, etc. In some embodiments, each of the first light sources 108 are configured to emit a first light 128. Depending upon the nature and construction of the first light source(s) 108, the first light 128 may correspond to light of a predetermined wavelength or color. More specifically, the first light source(s) 108 may be configured to produce and emit light 128 that is in the visible spectrum or invisible spectrum (e.g., Ultraviolet, Infrared, etc.). More specifically, where the first light source(s) 108 correspond to one or more LED dies, LED die(s) may be configured to emit the first light 128 when current is passed therethrough (e.g., when the LED is activated with current flowing from a wire or trace that can be part of the mounting substrate 104). Any type of known LED may be used for the first light source(s) 108 and the light source(s) 108 may be mounted and electrically connected to the mounting substrate 104 in any known fashion (e.g., via wires, bonding pads, surface contacts, etc.). Accordingly, the mounting substrate 104 may correspond to a rigid Printed Circuit Board (PCB), a flexible PCB, a PCB mounted on another substrate, or the like. The mounting substrate 104 may also comprise a heat sink member that is configured to dissipate heat produced by the first light source(s) 108 during operation.
The illumination device 100 may also comprise a second light source 112 or plurality of second light sources 112. The second light source(s) 112 may be physically separated from the mounting substrate 104 and the first light source(s) 108 by a first gap 144. In some embodiments, one or more sidewalls 124 extend from the mounting substrate 104 to connect the second light source(s) 112 with the mounting substrate 104. The sidewalls 124 may be configured to provide a physical support for the second light source(s) 112. One or more of the sidewalls 124 may also be configured to provide electrical current to the second light source(s) 112. As one example, one or more of the sidewalls 124 may comprise a metal component or components that carry current from a lead on the mounting substrate 104 to an electrode of the second light source(s) 112.
In some embodiments, the second light source(s) 112 may correspond to a sheet- or film-type light source. Even more particularly, the second light source(s) 112 may correspond to one or more flexible Organic LED (OLED) sheets that are mounted between the sidewalls 124. The second light source(s) 112 may be configured to emit second light 132 and third light 136 from an inner surface 116 and outer surface 120, respectively. In other words, when the second light source(s) 112 are activated by current supplied from the mounting substrate 104, the second light source(s) 112 may emit light across an extended area in both an upward and downward direction. In some embodiments, the sidewalls 124 may correspond to opaque or reflective material that is constructed to physically support the sides of the illumination device 100 as well as direct light within a cavity 148 of the illumination device 100 outward via the second light source(s) 112.
The first light 128 emitted by the first light source(s) 108 may appear as originating from a discrete point or source, whereas the second light 132 and third light 136 emitted by the second light source(s) 112 may appear as originating from a non-discrete area. The second light 132 may travel into the cavity 148 of the illumination device toward the first light source(s) 108. In some embodiments, the second light 132 may reflect off inner surfaces of the mounting substrate 104 and/or sidewalls 124 and eventually leave the illumination device 100 by passing through the second light source(s) 112. Additionally, the first light 128 may pass directly through the second light source(s) 112 and/or reflect off various inner surfaces of the illumination device 100 prior to passing through the second light source(s) 112. The light that eventually exits the illumination device 100 via the second light source(s) 112 may correspond to a sum of the first light 128, second light 132, and third light 136. Because the second light source(s) 112 are generally transparent or translucent, the amount of first light 128 and second light 132 blocked by the second light source(s) 112 is relatively minimal and the overall luminescence of the illumination device 100 is greater than if no second light source(s) 112 were employed. Moreover, because the second light source(s) 112 are configure to emit light from an extended area, the discrete or spot appearance of the first light 128 is obscured and the spottiness of the overall light output by the illumination device 100 is reduced. Accordingly, the illumination object 140 can be illuminated with bright light that is generally not spotty in nature.
In some embodiments, the color of the first light 128 output by the first light source(s) 108 may be similar or identical to the color of the second light 132 and third light 136 output by the second light source(s) 112. In other words, it may be desirable to match the color outputs of the light source(s) 108, 112 so that the overall light output of the illumination device 100 is consistent. In other embodiments, however, it may be desirable to use light source(s) 108, 112 that emit different colors of light.
Moreover, the cavity 148 may or may not be filled with a material that has light-altering properties. For instance, the cavity 148 may be simply filled with gas, such as air. In other embodiments, the cavity 148 may be filled with an encapsulant that is solid or semi-solid in nature. As some examples, the cavity 148 may be filled with epoxy, silicone, a hybrid of silicone and epoxy, phosphor, a hybrid of phosphor and silicone, an amorphous polyamide resin or fluorocarbon, glass, plastic, or combinations thereof. As another example, the first light source(s) 108 may be covered with an encapsulant to protect the light source(s) 108 and the remainder of the cavity 148 may be filled with air.
It should be appreciated that embodiments of the present disclosure are not limited to the particular type of illumination device 100 depicted in
To further illustrate,
The difference between the illumination device 200 and known illumination devices is that the illumination device 200 comprises a second light source 212 to compliment the first light source(s) 208. The first light source(s) 208 may correspond to discrete light sources, such a surface mount or thru-hole mount LEDs. The second light source 212 may correspond to a sheet- or film-type light source, such as an OLED sheet. One difference between the illumination device 200 and illumination device 100 is that the second light source 212 of the illumination device 200 may be configured to attach directly to the mounting substrate 204 rather than via one or more sidewalls. Additionally, the second light source 212 may be bent such that it is non-planar and emulates the shape of traditional tube lighting. The mounting substrate 204 may be similar or identical to the mounting substrate 104 in that it can be configured to support the first light source(s) 208 as well as provide electrical current to both light sources 208, 212.
In the depicted embodiment, the first light source(s) 208 are configured to emit first light 216 toward and through the second light source 212. The second light source 212 may be configured to emit second light 220 and third light 224. The second light 220 may be emitted into the cavity 228 that separates the first light source 208 from the second light source 212. Eventually, the second light 220 may reflect off the bottom surface of the mounting substrate 204 and pass through the second light source 212. The third light 224 may be directed away from the mounting substrate 204. Both the second light 220 and third light 224 may be emitted from a surface area while the first light 216 may be emitted from a smaller area or point source
As with the other illumination devices 100, 200, the illumination device 300 may comprise a mounting substrate 304 that provide the ability to physically support the first light source(s) 308 as well as carry electrical current thereto. Moreover, the mounting substrate 304 may comprise or be connected to one or more heat sinks.
Referring initially to the configuration depicted in
In some embodiments, the reflective walls 316 may establish a cavity 332 between the first light source(s) 308 and the second light source 312. First light 320 emitted by the first light source(s) 308 may travel through the cavity 332 and then pass through the second light source 312. The second light source 312 may be configured to emit second light 324 and third light 328. The second light 324 may be directed back into the cavity 332 toward the mounting substrate 304 and reflective walls 316 while the third light 328 may be emitted away from the mounting substrate 304.
Another feature included in the illumination device 300 is a reflective bottom surface 352 of the mounting substrate 304. Specifically, the mounting substrate 304 may comprise metallic reflective material and/or white polymer material to help reflect the second light 324 and any other light within the cavity 332 back toward the second light source 312. In some embodiments, the majority (e.g., more than 50%) of the reflective bottom surface 352 may correspond to a white polymer material.
The cover 344 or diffractive cover 336 may be manufactured of glass, polymers, or any other transparent or translucent material known in the lighting arts. As with the diffractive cover 336, the cover 344 may be manufactured separately and then attached to the second light source 312 or the second light source 312 may be mounted on the cover 344 as part of manufacturing the second light source 312 and prior to mounting the second light source 312 and cover 344 onto the reflective walls 316.
Any feature described in connection with one illustrative illumination device may be used or provided in connection with another illustrative illumination device. For instance, one or more features of the illumination device 300 depicted in any of
With reference now to
Before, during, or after the mounting and connecting of the first light source(s), the method continues with the mounting of one or more second light source(s) around the first light source(s) (step 412). Depending upon the configuration of the illumination device, the second light source(s) may be mounted in a planar or bent configuration. Additionally, depending upon the type of fixture desired, the second light source(s) may be connected directly to the same base or substrate to which the first light source(s) were mounted or the second light source(s) may be connected to the base or substrate via an intermediate member (e.g., reflective wall, sidewall, etc.).
As with the first light source(s), the second light source(s) may then be electrically connected to a current source (step 416). This step may be performed before, during, or after any of steps 404, 408, and 412. For example, if the component used to physically support the second light source(s) also comprises the components to carry electrical current to the second light source(s), then the mounting step and electrical connection step may occur simultaneously. Alternatively, it may be possible to physically connect the second light source(s) first and then establish an electrical pathway with separate leads.
Additional steps may be taken to finish the construction of the illumination device. For instance, if a cover or some other additional component is desired for the illumination device, then such a component may be connected to the device.
Once constructed, the method may be completed with the installation of the illumination device at its desired location (step 420). It should be noted that the illumination device may be installed to replace existing lighting fixtures, which may or may not comprise LED light sources. The installation may alternatively correspond to a new installation. Moreover, the desired location may correspond to one or more of a ceiling, wall, floor, hanging, or hidden location.
With reference now to
In some embodiments, a single driver circuit or single current source may be used to activate the discrete LED components and OLED components. In some embodiments, a first driver circuit may be used to drive the discrete LED components while a second driver circuit may be used to drive the OLED components. In the latter scenario, it may be possible to individually control whether one or both light sources are active at the same time.
Specific details were given in the description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.
While illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.
