Patent Application
20120001531
This application claims priority from Korean Application No. 10-2010-0062951 filed Jun. 30, 2010, the subject matter of which is incorporated herein by reference.
1. Field
Embodiments of the present invention may relate to a lamp and a method for manufacturing the same.
2. Background
An incandescent lamp, a halogen lamp, a discharge lamp and/or the like have been used as a lamp. A Light Emitting Diode (LED) has also been used. LED based lamps may use an LED member as a light source. The LED member may emit a light as minority carriers injected, by using a semiconductor P-N junction structure, are generated and re-coupled again. Light from the LED member may have a wavelength that varies based on kinds of impurities added thereto, thereby enabling the LED member to emit a red color, a blue color, and/or a yellow color, and to produce a white color by an appropriate combination of the colors. The LED member may be advantageous in that the LED member may have a smaller size, a longer lifetime, a better efficiency, and/or a faster response than a light source such as the incandescent lamp, and/or the halogen lamp.
If an LED based lamp is used as a mere lighting, a direction of the light may be offset by using a non-transparent diffusion cap. If the direction of the light is required for a particular purpose, a lens structure may guide the light from the LED member in a particular direction.
The LED based lamp having a directional light may have a lens unit (or lens) or a combination of a lens unit and a reflector. By using the lens unit and the reflector, light from the LED member may have a direction that is incident on a desired region.
As shown in
Arrangements and embodiments may be described in detail with reference to the following drawings in which like reference numerals refer to like elements and wherein:
a), 5(b), and 5(c) illustrate a rear side view, a front side view, and a sectional view of the lens unit in
a) and 7(b) illustrate photographs showing operations of an LED based lamp according to an arrangement and an LED based lamp in accordance with an example embodiment of the present invention, respectively.
Reference may now be made in detail to specific arrangements and embodiments of the present invention, examples of which may be illustrated in the accompanying drawings. Wherever possible, same reference numbers may be used throughout the drawings to refer to the same or like parts. The LED based lamp described below may be exemplary, as other types of LED based lamps may also be provided.
The LED module 400 may have an LED 420 (or LED member) that generates heat during operation. The LED module 400 may be mounted in the housing 600. The housing 600 may have a receiving part 630 of a predetermined shape. The LED module 400 may be provided in the receiving part 630 with a fastening member, such as a bolt b1. In order to effectively dissipate heat from the LED module 400, the housing 600 may be formed of metal. Heat dissipation fins (or cooling fins) may be provided on an outside surface of the housing 600.
The lens unit 200 may be provided in front of the LED module 400 (i.e., an upper side of
The base 700 may be coupled to a rear of the housing 600 (i.e., a lower side of
The lens unit 200 may be described with reference to
The lens unit 200 may include a lens 220 for receiving light from the LED 420 and for guiding the light to a specific area. The lens unit 200 may also include a window 240 (or part) that is an outward extension from a circumference of the lens 220.
The lens 220 may project toward the LED module 400. The lens 220 may have a hollow part 220g for providing the LED 420 therein, and an outside surface that is a sloped surface 220s with a predetermined curvature for making a total reflection of the light. A front surface of the lens unit 200 may be a light emission surface 210, and the light emission surface 210 may have a microlens array 210a. The microlens array 210a may be a plurality of micron sized lenses provided to a light emission surface 210. The microlens array 210a provided to the light emission surface 210 may increase light distribution efficiency and improve a quality of emitted light.
An adjustor 900, as shown in
The LED 420 of the LED module 400 may have the hollow part 220g provided therein, for making the light from the LED 420 to be incident on the hollow part 220g. The light incident on the hollow part 220g may be totally reflected at the sloped surface 220s so as to be directed to the light emission surface 210. That is, the total reflection at the sloped surface 220s may make the light from the LED 420 to be directed to a desired light incident region. However, since the total reflection of the entire light may actually be difficult, the reflector 300 may be used for surrounding an outside of the lens unit 200.
Since the window 240 is not a region on which the light from the LED 420 is directly incident, the window 240 may not have any particular lens function. The window 240 may be a part used for entire sizes of the lens unit 200 and may be standardized for convenience of assembly. However, light transmitted through the lens unit 220 and irregularly reflected at or scattered from the reflector 300 may be incident on the window 420.
Light B1, B2 and BS from the LED 420 may be guided by the lens unit 200. The light BR reflected at a part of the light emission surface 210 may be returned after re-reflected at the sloped surface 220s of the lens 220 or may be reflected by the reflector 900.
Since the lens unit 200 may be designed to make the light to be incident on the defined incident region (i.e., a desired incident region), the light through the lens 200 may be incident on the defined light incident region. However, as described with respect to
Embodiments of the present invention may provide the adjustor 900 on a predetermined position of the lens unit 200 for minimizing light emitting from the light emission surface 210 of the lens unit 200, to prevent the light BS from being incident to outside of the light incident region. The adjustor 900 may be provided on the lens 220 to minimize light from being transmitted to a region outside of a specific area. The adjustor 900 may have a different surface roughness than an inner surface of the lens 220. The adjustor 900 may also have a different light transmissivity than the inner surface of the lens 220. The adjuster 900 may be considered as part of the lens unit 200.
The unintended light BS may cause a problem at a boundary of the defined light incident region because the light within the light incident region may be included to a range of the light incident region again even when a portion thereof refracts. The adjustor 900 may be positioned at a boundary of the light incident region, and more preferably in a ring shape. If the window 240 is provided to the lens unit 200, since there are many cases of undesired light emission from the boundary between the lens 220 and the window 240, the adjustor 900 may include the window 240. Locations at which the adjustor 900 may be positioned are not limited to above, but may be determined according to simulation or experiment in view of a nature of the light. For example, the adjustor 900 may be positioned at a particular position of the lens 220.
Types of the adjustor 900 are not limited, since the adjustor 900 is merely one type of device to prevent light from emitting to an outside of the light incident region. The adjustor 900 may have parts with micron unevenness (i.e., a micron surface roughness relatively greater than the surface roughness of the lens unit 200) because a plurality of the micron uneven parts may be formed by polishing or sand blasting. At the time of manufacturing the lens unit 200, a relevant part of a mold of the lens unit 200 may be sand blasted to form the micron unevenness at the adjustor 900 when the lens unit 200 is molded with the mold sand blasted at the end. The uneven part may be provided to at least one of a front surface and a rear surface of the lens unit 200. This configuration may minimize emission of the light to outside of the light incident region as the light takes another path (i.e., an inside of the light incident region) during which the light repeats reflection and refraction within the adjustor 900 without going to an outside of the light emission surface, but returning into the lens unit 200 again owing to a relatively greater surface roughness of the adjustor 900 than the other part of the lens unit 200.
Although the surface roughness of the adjustor 900 may not be defined, the surface roughness may be selected such that a total flux of light is not reduced while the unintended emission of the light is prevented. According to a study, even though the total flux of light is reduced by more than approximately 4% if the micron unevenness is a few hundreds of microns compared to an example when there is no change of the surface roughness, the total flux of light may be reduced by below approximately 0.6% when the micron unevenness is a few tens of microns compared to an example when there is no change of the surface roughness. Therefore, reduction of the total flux of light may be minimized by appropriate selection of the surface roughness. Additionally, an entire lens unit may have a predetermined surface roughness without limiting to the adjustor 900. This may permit easy manufacturing of the lens unit 200. In this example, the front surface and/or the rear surface of the lens unit 200 may also have a predetermined surface roughness.
Production of the adjustor 900 may not be limited to a change of the surface roughness. For example, by making light transmissivity of the adjustor 900 smaller than the other part of the lens unit 200, light emission through this part may also be minimized. For example, the adjustor 900 may be made not to actually transmit the light. The adjustor 900 may absorb or reflect the light to a certain extent. If the adjustor 900 absorbs the light, since adjustor 900 is liable to absorb the light re-reflected also at the reflector, reducing the total flux of light, the adjustor 900 may also reflect the light.
Although the above description relates to the adjustor 900 being formed as one unit with the lens unit 200, embodiments of the present invention are not limited to this. The manufacturing of the adjustor 900 as a separate member and appropriate coupling of the adjustor 900 with the lens unit 200 may also be provided.
Operation of the LED based lamp in accordance with an example embodiment may be described with reference to
As can be seen from
An LED based lamp and a method for manufacturing the same of the present invention may have advantages. For example, by minimizing light incident on an outside of the intended light incident region, a light distribution may be improved. Additionally, by making the light incident on an outside of the intended light incident region to be incident on the intended light incident region again, a total flux of light and the light distribution efficiency may be improved.
Embodiments of the present invention may provide an LED based lamp and a method for manufacturing the same that can improve a light distribution.
Embodiments of the present invention may provide an LED based lamp and a method for manufacturing the same that can improve a total flux of light.
An LED based lamp may include a housing (or heat sink) having an LED module provided thereto, a lens unit for inducing a light from the LED module to a defined light incident region, and an adjustor for minimizing light incident to outside of the light incident region.
The adjustor may be provided at a part of the lens unit corresponding to a boundary of the light incident region. The lens unit may include a lens and a window around a circumference of the lens. The adjustor may be provided at a part that includes a boundary of the lens and the window.
The adjustor may be a plurality of uneven parts. The uneven parts may have a surface roughness determined to minimize reduction of total flux of light from the lens unit. The surface roughness of the uneven parts may be a few tens of microns. The uneven parts may be provided on at least one of a front surface and a rear surface of the lens unit.
The adjustor may have light transmissivity lower than other parts of the lens unit. The adjustor may not transmit light. The adjustor may actually reflect the light.
The adjustor may cause irregular reflection of the light. The adjustor may cause total reflection of the light.
The adjustor may be formed as one unit with the lens unit.
A method for manufacturing an LED based lamp may include determining a lens unit to induce a light from an LED module to a defined light incident region, and adjusting for minimizing the light incident to outside of the light incident region. The adjusting may include making a surface roughness of a predetermined part of the lens unit different from the other part of the lens unit. The adjusting may also include making light transmissivity of a predetermined part of the lens unit different from the other part of the lens unit.
Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to affect such feature, structure, or characteristic in connection with other ones of the embodiments.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2010-0062951 | Jun 2010 | KR | national |
