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Title:
LIGHTING APPARATUS AND METHOD OF FORMING THE SAME
Document Type and Number:
WIPO Patent Application WO/2017/151056
Kind Code:
A1
Abstract:
According to embodiments of the present invention, a lighting apparatus is provided. The lighting apparatus includes a light guiding arrangement, a light collection arrangement adapted to collect sunlight, the light guiding arrangement being optically coupled to the light collection arrangement to receive at least a portion of the sunlight collected for propagation through the light guiding arrangement, and a light source arrangement configured to generate an illumination light, the light guiding arrangement being optically coupled to the light source arrangement to receive at least a portion of the illumination light for propagation through the light guiding arrangement. According to further embodiments of the present invention, methods of forming a lighting apparatus are also provided.

Inventors:
CHIA, Ho Meng @ Tay Ho Meng (25 Tagore Lane,#03-10 Singapore G Building, Singapore 2, 787602, SG)
ZHUANG, Zhenfeng (50 Nanyang Avenue, Singapore 8, 639798, SG)
CAO, Bin (50 Nanyang Avenue, Singapore 8, 639798, SG)
LIM, Jin Siew (50 Nanyang Avenue, Singapore 8, 639798, SG)
SUN, Xiaowei (50 Nanyang Avenue, Singapore 8, 639798, SG)
Application Number:
SG2017/050087
Publication Date:
September 08, 2017
Filing Date:
February 27, 2017
Export Citation:
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Assignee:
NANYANG TECHNOLOGICAL UNIVERSITY (50 Nanyang Avenue, Singapore 8, 639798, SG)
TECHNOLITE (SINGAPORE) PTE LTD (25 Tagore Lane, #03-10 Singapore G Building, Singapore 2, 787602, SG)
International Classes:
F21S19/00; F21S11/00; F24S23/00; G02B6/00
Foreign References:
US20160033100A12016-02-04
KR20110016839A2011-02-18
KR20110119430A2011-11-02
CN101515062A2009-08-26
CN101634746A2010-01-27
CN105351881A2016-02-24
Other References:
SOYDAN Y. ET AL.: "Lighting of Commercial Buildings by Conveying Sunlight", JOURNAL OF SCIENCE AND TECHNOLOGY, vol. 1, no. 1, 31 December 2011 (2011-12-31), pages 21 - 41, XP055415054, [retrieved on 20170529]
MANI P. ET AL.: "Energy Saving Hybrid Solar Lighting System Model For Small Houses", WORLD APPLIED SCIENCES JOURNAL, vol. 33, no. 3, 31 December 2015 (2015-12-31), pages 460 - 465, XP055415056, [retrieved on 20170529]
Attorney, Agent or Firm:
MCLAUGHLIN, Michael Gerard (Mclaughlin IP Pte Ltd, 24A Mosque Street, Singapore 4, 059504, SG)
Download PDF:
Claims:
CLAIMS

1. A lighting apparatus comprising:

a light guiding arrangement;

a light collection arrangement adapted to collect sunlight, the light guiding arrangement being optically coupled to the light collection arrangement to receive at least a portion of the sunlight collected for propagation through the light guiding arrangement; and

a light source arrangement configured to generate an illumination light, the light guiding arrangement being optically coupled to the light source arrangement to receive at least a portion of the illumination light for propagation through the light guiding arrangement.

2. The lighting apparatus as claimed in claim 1, wherein the light source arrangement is adapted to allow another portion of the illumination light to illuminate a surrounding of the lighting apparatus.

3. The lighting apparatus as claimed in claim 1 or 2, wherein the light collection arrangement is further configured to refract the sunlight collected towards the light guiding arrangement.

4. The lighting apparatus as claimed in any one of claims 1 to 3, wherein the light collection arrangement is further configured to converge the sunlight collected. 5. The lighting apparatus as claimed in claim 4, wherein the light collection arrangement comprises at least one solar concentrator.

6. The lighting apparatus as claimed in claim 5, wherein the light collection arrangement comprises a plurality of solar concentrators arranged tilted relative to a horizontal axis to collect the sunlight.

7. The lighting apparatus as claimed in claim 6, wherein the plurality of solar concentrators are arranged to at least substantially surround the light source arrangement.

8. The lighting apparatus as claimed in any one of claims 1 to 7, further comprising an optical coupling element adapted to receive and optically couple the portion of the sunlight collected and the portion of the illumination light into the light guiding arrangement.

9. The lighting apparatus as claimed in claim 8, wherein the optical coupling element is movable relative to the light source arrangement.

10. The lighting apparatus as claimed in any one of claims 8 to 9, when dependent on claim 5, wherein the optical coupling element is arranged at a focal plane of the at least one solar concentrator.

11. The lighting apparatus as claimed in any one of claims 1 to 10, wherein the light guiding arrangement comprises at least one optical fiber adapted to receive the portion of the sunlight collected and the portion of the illumination light for propagation through the at least one optical fiber.

12. The lighting apparatus as claimed in any one of claims 1 to 11, wherein the light source arrangement comprises at least one light emitting diode.

13. The lighting apparatus as claimed in any one of claims 1 to 12, further comprising a light distribution arrangement optically coupled to the light guiding arrangement to receive and distribute at least one of the portion of the sunlight or the portion of the illumination light propagated through the light guiding arrangement over a space for illumination of the space.

14. The lighting apparatus as claimed in any one of claims 1 to 13, further comprising a control system adapted to control generation of the illumination light by the light source arrangement. 15. The lighting apparatus as claimed in claim 14, wherein the control system comprises a light-sensitive sensor.

16. The lighting apparatus as claimed in any one of claims 1 to 15, wherein the lighting apparatus is free of a sun tracker device.

17. The lighting apparatus as claimed in any one of claims 1 to 16, wherein the lighting apparatus comprises a lamp post.

18. A method of forming a lighting apparatus, the method comprising:

providing a light guiding arrangement;

providing a light collection arrangement adapted to collect sunlight, and arranging the light guiding arrangement to be optically coupled to the light collection arrangement to receive at least a portion of the sunlight collected for propagation through the light guiding arrangement; and

providing a light source arrangement configured to generate an illumination light, and arranging the light guiding arrangement to be optically coupled to the light source arrangement to receive at least a portion of the illumination light for propagation through the light guiding arrangement. 19. A method of forming a lighting apparatus, the method comprising:

arranging a light guiding arrangement to be optically coupled to a light collection arrangement adapted to collect sunlight so as to receive at least a portion of the sunlight collected for propagation through the light guiding arrangement; and

arranging the light guiding arrangement to be optically coupled to a light source arrangement configured to generate an illumination light so as to receive at least a portion of the illumination light for propagation through the light guiding arrangement.

Description:
LIGHTING APPARATUS AND METHOD OF FORMING THE SAME

Cross-Reference to Related Application

[0001] This application claims the benefit of priority of Singapore patent application No. 10201601669U, filed 4 March 2016, the content of it being hereby incorporated by reference in its entirety for all purposes.

Technical Field

[0002] Various embodiments relate to a lighting apparatus and a method of forming the lighting apparatus.

Background

[0003] It is known that fossil fuels have been mostly used as energy provision for living; however, it causes global warming due to the greenhouse effect. The earth may suffer catastrophic damage due to the irreversible increase in greenhouse gases in the atmosphere, which could cause glacier melting, species extinction, etc. To combat the adverse effects of burning fossil fuels for generating energy, there is an urgent need for techniques that could provide energy at low cost and with less, or no greenhouse gas emission.

[0004] Solar cells are the most commonly used device in Photovoltaics (PV). However, solar cells cannot significantly reduce greenhouse gases emission in the atmosphere. Moreover, one of the key issues of solar cells is cost. There is very little opportunity for solar cells to have a significant impact on decreasing greenhouse gases in the atmosphere if the cost of solar generated electricity energy is more than that of fossil fuel burning. As a result, technical limitations and high cost considerably restrict their application.

[0005] The idea of collecting sunlight for indoor lighting was originally proposed around fifty years ago. The concept of redirecting sunlight by using reflective or refractive optical elements to indoor was also developed. Such systems are able to meet certain basic requirements for general lighting in the daytime. Since 1875, lamp posts have been used to illuminate the vicinity of public place after sunset. The development of semiconductor technology in conjunction with light-emitting diodes (LEDs) enable a reduction in power consumption in lamp posts. This is not practical in the case of conventional light bulbs, halogen bulbs and sodium lamps. Recently, hybrid daylight illumination and LED lighting systems for indoor lighting have been developed.

Summary [0006] According to an embodiment, a lighting apparatus is provided. The lighting apparatus may include a light guiding arrangement, a light collection arrangement adapted to collect sunlight, the light guiding arrangement being optically coupled to the light collection arrangement to receive at least a portion of the sunlight collected for propagation through the light guiding arrangement, and a light source arrangement configured to generate an illumination light, the light guiding arrangement being optically coupled to the light source arrangement to receive at least a portion of the illumination light for propagation through the light guiding arrangement.

[0007] According to an embodiment, a method of forming a lighting apparatus is provided. The method may include providing a light guiding arrangement, providing a light collection arrangement adapted to collect sunlight, and arranging the light guiding arrangement to be optically coupled to the light collection arrangement to receive at least a portion of the sunlight collected for propagation through the light guiding arrangement, and providing a light source arrangement configured to generate an illumination light, and arranging the light guiding arrangement to be optically coupled to the light source arrangement to receive at least a portion of the illumination light for propagation through the light guiding arrangement.

[0008] According to an embodiment, a method of forming a lighting apparatus is provided. The method may include arranging a light guiding arrangement to be optically coupled to a light collection arrangement adapted to collect sunlight so as to receive at least a portion of the sunlight collected for propagation through the light guiding arrangement, and arranging the light guiding arrangement to be optically coupled to a light source arrangement configured to generate an illumination light so as to receive at least a portion of the illumination light for propagation through the light guiding arrangement. Brief Description of the Drawings

[0009] In the drawings, like reference characters generally refer to like parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the invention are described with reference to the following drawings, in which:

[0010] FIG. 1A shows a schematic block diagram of a lighting apparatus, according to various embodiments.

[0011] FIG. IB shows a flow chart illustrating a method of forming a lighting apparatus, according to various embodiments.

[0012] FIG. 1C shows a flow chart illustrating a method of forming a lighting apparatus, according to various embodiments.

[0013] FIG. 2 shows a schematic diagram illustrating a lighting application of the lighting apparatus of various embodiments.

[0014] FIG. 3A shows a schematic cross sectional view of a lighting apparatus, according to various embodiments.

[0015] FIG. 3B shows a schematic top view of the lighting apparatus of FIG. 3A.

[0016] FIGS. 4A and 4B show schematic cross sectional views illustrating a lighting application of the lighting apparatus of FIG. 3A at different times of the day.

[0017] FIG. 5 shows a schematic cross sectional view illustrating a lighting application of the lighting apparatus of FIG. 3A after sunset.

[0018] FIG. 6 shows a schematic cross sectional view illustrating a lighting application of a lighting apparatus, according to various embodiments.

[0019] FIG. 7 shows a schematic block diagram illustrating a compensation control scheme, according to various embodiments. Detailed Description

[0020] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the invention. The various embodiments are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.

[0021] Embodiments described in the context of one of the methods or devices are analogously valid for the other methods or devices. Similarly, embodiments described in the context of a method are analogously valid for a device, and vice versa.

[0022] Features that are described in the context of an embodiment may correspondingly be applicable to the same or similar features in the other embodiments. Features that are described in the context of an embodiment may correspondingly be applicable to the other embodiments, even if not explicitly described in these other embodiments. Furthermore, additions and/or combinations and/or alternatives as described for a feature in the context of an embodiment may correspondingly be applicable to the same or similar feature in the other embodiments.

[0023] In the context of various embodiments, the articles "a", "an" and "the" as used with regard to a feature or element include a reference to one or more of the features or elements.

[0024] In the context of various embodiments, the phrase "at least substantially" may include "exactly" and a reasonable variance.

[0025] As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

[0026] As used herein, the phrase of the form of "at least one of A or B" may include A or B or both A and B. Correspondingly, the phrase of the form of "at least one of A or B or C", or including further listed items, may include any and all combinations of one or more of the associated listed items. [0027] Various embodiments may provide a hybrid solar lighting lamp structure for all- day illumination.

[0028] Various embodiments may provide a structure that embeds a solar lighting system into a lamp post for outdoor public area and indoor lighting illumination. The hybrid light-emitting diode (LED) illumination and solar lighting system includes one or more LED arrays, one or more solar concentrators, an optical coupling element (OCE) (e.g., which may also be defined as a secondary optical element (SOE)) and one or more optical fibers. The solar concentrator(s) may be arranged such that they are tilted towards the sun during the daytime in order to increase efficiency in the capture of sun radiation. As a result, a sun-tracker is not required in various embodiments. The rays from the sun are refracted by the concentrator(s) to the OCE, which is used to increase the acceptance angle of the solar concentrator(s). The OCE may then distribute all the rays over the optical fibers into an indoor environment (e.g., car park). In various embodiments, the LED array(s) and the LED driver may be mounted at the center of the lamp post rather than at the light distribution arrangement or system, and the one or more solar concentrators may circularly surround the LED array(s). At night, the LED array(s) may be turned on to illuminate both the outdoor public area and the indoor environment simultaneously. Additionally or alternatively, a movable OCE may be used to collect all of the light rays from the partially or fully turned on LED during the time when natural sunlight may be insufficient for providing illumination to an indoor environment and the LED may not be required to provide lighting to an outdoor public area. In the daytime, the static solar concentrator structure may collect enough energy from the sun even if the solar radiation intensity varies.

[0029] Various embodiments may provide a hybrid solar lighting lamp structure which embeds at least one solar concentrator into a lamp post. The hybrid solar lighting lamp system combined with an LED lighting source and one or more solar concentrators may provide the desired illumination for both indoor and outdoor public areas. Such a technology or approach has the ability to reduce power consumption and/or provide sufficient illumination for indoor lighting.

[0030] A sun-tracker is widely used in known solar concentrators to maintain a high level of efficiency; however, it inevitably increases cost. Various embodiments use one or more concentrator arrays which may be arranged in a hemispherical or dome shape in order to enhance the capture efficiency of sunlight during the daytime. Hence, various embodiments may not or does not require a sun-tracker. In addition to cost saving, in various embodiments, an additional useful function may be provided by one or more LED arrays placed at the top portion of the lamp post. The LED array(s) not only provide indoor lighting when the natural illumination is insufficient to meet the brightness requirements, but also provide illumination to an outdoor public area. Further, in various embodiments, using a movable OCE may increase energy efficiency. As a result, the use of the hybrid solar lighting lamp of various embodiments may considerably reduce power consumption.

[0031] The concept of trapping sunlight with fiber optics, so as to illuminate underground facilities, may be attractive enough to seed future lighting solution of common facilities, e.g., an underground car park. Sunlight can now replace artificial lighting for some portion of the day. The same artificial light source may also perform a dual function of lighting an immediate surrounding during night time. The dual function may provide a compelling case for use in modern city planning, where space constrains necessitate underground infrastructure to increase the usable space for the community.

[0032] FIG. 1A shows a schematic block diagram of a lighting apparatus 100, according to various embodiments. The lighting apparatus 100 includes a light guiding arrangement 102, a light collection arrangement 104 adapted to collect sunlight (as represented by the solid arrow 112a), the light guiding arrangement 102 being optically coupled (as represented by the dashed line 116a) to the light collection arrangement 104 to receive at least a portion (as represented by the solid arrow 112b) of the sunlight 112a collected for propagation through the light guiding arrangement 102, and a light source arrangement 106 configured to generate an illumination light (as represented by the dashed arrow 114a), the light guiding arrangement 102 being optically coupled (as represented by the dashed line 1 16b) to the light source arrangement 106 to receive at least a portion (as represented by the dashed arrow 114b) of the illumination light 114a for propagation through the light guiding arrangement 102.

[0033] In other words, a lighting apparatus 100 for lighting or illumination of an area or space may be provided. The lighting apparatus 100 may include a light guiding arrangement 102 (e.g., having one or more light guides) that may receive light and guide the light to propagate through (or within) the light guiding arrangement 102. In this way, the light guiding arrangement 102 may act as an optical waveguiding arrangement.

[0034] The lighting apparatus 100 may further include a light collection arrangement 104 (e.g., having one or more light collectors) that may collect or receive sunlight (or rays from the sun) 112a. The light collection arrangement 104 may collect sunlight and may direct at least a portion 112b of the sunlight 1 12a that is collected to or towards the light guiding arrangement 102. The sunlight 112a collected may be transmitted through the light collection arrangement 104. This may mean that the light collection arrangement 104 or any light collection element thereof may be optically (or light) transmissive (or transparent). It should be appreciated that the light guiding arrangement 102 may receive some or all of the sunlight 112a collected by the light collection arrangement 104. For example, the portion 112b received by the light guiding arrangement 102 may be the entire sunlight 1 12a collected by the light collection arrangement 104.

[0035] The lighting apparatus 100 may further include a light source arrangement 106 (e.g., having one or more light sources) that may generate an illumination light 114a to be provided to the light guiding arrangement 102. The light source arrangement 106 may direct at least a portion 1 14b of the illumination light 114a that is generated to or towards the light guiding arrangement 102. It should be appreciated that the light guiding arrangement 102 may receive some or all of the illumination light 114a generated by the light source arrangement 106. For example, the portion 114b received by the light guiding arrangement 102 may be the entire illumination light 114a generated by the light source arrangement 106. The light source arrangement 106 may be positioned at a (vertical) central axis of the lighting apparatus 100. As a non-limiting example, the illumination light 114a may be white light.

[0036] In various embodiments, the light source arrangement 106 may include or may be an active light source arrangement and/or an artificial light source arrangement. By "active", it is meant that the light source arrangement 106 requires an energy source for the illumination light 114a to be generated. This may mean that the light source arrangement 106 may receive energy from the energy source (for example, electrical energy, e.g., from electricity (electrical current) or battery), for example, by being connected to the energy source, to generate the illumination light 114a. In other words, the light source arrangement 106 may be powered by an energy source for the illumination light 114a to be generated by the light source arrangement 106.

[0037] As described above, the lighting apparatus 100 may include a combination of a solar lighting arrangement (or system) and an active illumination lighting arrangement (or system).

[0038] In various embodiments, the light guiding arrangement 102 may be optically coupled to the light collection arrangement 104 to receive at least a portion 112b of the sunlight 112a collected by the light collection arrangement 104 and further optically coupled to the light source arrangement 106 to receive at least a portion 114b of the illumination light 114a. It should be appreciated that this means that the light guiding arrangement 102 may be capable of receiving the portion 112b of the sunlight 112a and the portion 114b of the illumination light 114a, where it may not be necessary that the light guiding arrangement 102 receives both portions 112b, 114b simultaneously at any one time, although this may be possible. For example, in one mode of operation (e.g., during daytime), the light guiding arrangement 102 may receive the portion 112b of the sunlight 112a collected, and in another mode of operation (e.g., during nighttime), the light guiding arrangement 102 may receive the portion 114b of the illumination light 114a.

[0039] In various embodiments, the light collection arrangement 104 may be arranged towards or at an upper (or top) portion of the lighting apparatus 100. Such positioning may optimize collection of the sunlight 112a.

[0040] In various embodiments, at least one of the portion 112b of the sunlight 112a or the portion 114b of the illumination light 114a may propagate through (or within) the light guiding arrangement 102 to be provided or guided to a remote area or space, e.g., an indoor space, an underground space, etc., that may be away from the lighting apparatus 100.

[0041] In various embodiments, the light source arrangement 106 may be adapted or positioned to allow another portion of the illumination light 114a to illuminate a surrounding of the lighting apparatus 100. This means that the other portion of the illumination light 114a generated by the light source arrangement 106 may be provided to illuminate or light up an immediate surrounding or vicinity of the lighting apparatus 100. For example, the other portion of the illumination light 114a may illuminate an area or space where the lighting apparatus 100 may be positioned.

[0042] In various embodiments, the light collection arrangement 104 may be further configured to refract the sunlight 112a collected towards (or to) the light guiding arrangement (e.g., to at least one optical fiber) 102. This may mean that the sunlight 112a collected may be directed by the light collection arrangement 104 in a direction towards (or to) the light guiding arrangement 102. For example, an optical path of the sunlight 112a collected may be changed towards (or to) the light guiding arrangement 102.

[0043] In various embodiments, the light collection arrangement 104 may be further configured to converge (or focus) the sunlight 112a collected, for example, towards (or to) the light guiding arrangement 102.

[0044] In various embodiments, the sunlight that has been refracted and/or focused may be received by an OCE to be optically coupled to or into the light guiding arrangement 102.

[0045] In various embodiments, the light collection arrangement 104 may include at least one solar concentrator. The at least one solar concentrator may act as a light collection element. The at least one solar concentrator may be configured to refract and/or converge (or focus) the collected sunlight 112a. Consider, for example, a planar refracting lens which may be used as a solar concentrator or collector. The at least one solar concentrator may be arranged towards or at an upper (or top) portion of the lighting apparatus 100.

[0046] In various embodiments, the light collection arrangement 104 may include a plurality of solar concentrators arranged tilted relative to a horizontal axis to collect the sunlight 112a. For example, each solar concentrator may be arranged tilted downwardly towards a ground level. The plurality of solar concentrators may be arranged tilted to collectively resemble a hemispherical or dome shape. By providing such an arrangement of tilted solar concentrators, at least one solar concentrator may face or be oriented in the direction of the sun to collect the sunlight 112a as the day progresses with consequential movement of the sun relative to the lighting apparatus 100. In various embodiments, the plurality of solar concentrators may be arranged around a (vertical) central axis of the lighting apparatus 100. In various embodiments, the plurality of solar concentrators may be arranged to at least substantially surround the light source arrangement 106.

[0047] In various embodiments, the lighting apparatus 100 may further include an optical coupling element (OCE) (or optical coupler) adapted to receive and optically couple the portion 112b of the sunlight 112a collected and the portion 114b of the illumination light 114a into the light guiding arrangement 102. It should be appreciated that this means that the OCE may be capable of receiving and optically coupling the portion 112b of the sunlight 112a and the portion 114b of the illumination light 114a into the light guiding arrangement 102, where it may not be necessary that the OCE receives both portions 112b, 114b simultaneously at any one time, although this may be possible. The OCE may be adapted to receive the sunlight that has interacted with the light collection arrangement 104. For example, the sunlight 112a collected may be converged to or into the OCE. The OCE may be arranged below at least one of the light collection arrangement 104 or the light source arrangement 106. The OCE may be arranged at or optically coupled to an input end of the light guiding arrangement 102. The OCE may be arranged in an optical path between the light collection arrangement 104 and the light guiding arrangement 102 and in an optical path between the light source arrangement 106 and the light guiding arrangement 102. As non-limiting examples, the OCE may be a kaleidoscope-type homogenizer using the operating principle of total internal reflection (TIR).

[0048] In various embodiments, the OCE may be part of or comprised in the light guiding arrangement 102.

[0049] In various embodiments, the OCE may be movable relative to the light source arrangement 106. For example, the OCE may be movable in a direction towards the light source arrangement 106, to optimize receipt of the illumination light 114a. It should be appreciated that the OCE may be movable bi-directionally towards and away from the light source arrangement 106.

[0050] In various embodiments, the OCE may be arranged at a focal plane of the at least one solar concentrator. The focal plane means the plane where a focal point associated with the at least one solar concentrator may be located. This may mean that the distance between the OCE and the at least one solar concentrator may be at least substantially equal to the focal length of the at least one solar concentrator.

[0051] In various embodiments, the light guiding arrangement 102 may include at least one optical fiber adapted to receive the portion 1 12b of the sunlight 112a collected and the portion 114b of the illumination light 1 14a for propagation through the at least one optical fiber. It should be appreciated that this means that the at least one optical fiber or each optical fiber may be capable of receiving the portion 112b of the sunlight 112a and the portion 114b of the illumination light 114a, where it may not be necessary that the at least one optical fiber or each optical fiber receives both portions 1 12b, 1 14b simultaneously at any one time, although this may be possible. The at least one optical fiber may receive the portion 112b of the sunlight 112a collected and the portion 114b of the illumination light 114a via the OCE. It should be appreciated that the light guiding arrangement 102 may include a plurality of optical fibers. Each respective optical fiber of the plurality of optical fibers may be associated with a respective solar concentrator of a plurality of solar concentrators.

[0052] In various embodiments, the light source arrangement 106 may include at least one light emitting diode (LED). It should be appreciated that the light source arrangement 106 may include a plurality of light emitting diodes (LEDs). The plurality of light emitting diodes (LEDs) may be provided in respective (or separate) LED modules, where each LED module may include one or more LEDs. As non-limiting examples, where the illumination light 114a may be white light, the at least one LED may be a white light LED, or the light source arrangement 106 may include a combination of red, green and blue LEDs, to generate the white illumination light 114a.

[0053] In various embodiments, the lighting apparatus 100 may further include a light distribution arrangement (e.g., having one or more light distributors) optically coupled to the light guiding arrangement 102 to receive and distribute at least one of the portion 112b of the sunlight 112a or the portion 114b of the illumination light 114a propagated through the light guiding arrangement 102 over a space for illumination of the space. The light distribution arrangement may be arranged at or optically coupled to an output end of the light guiding arrangement 102. As a non-limiting example, a conical reflector or a total reflection lens may be used as a light distribution component or light distributor, or may be used as part of the light distribution arrangement.

[0054] In various embodiments, the lighting apparatus 100 may further include a control system (or control circuit) adapted to control generation of the illumination light 114a by the light source arrangement 106. The control system may be electrically coupled or (electrically) connected to the light source arrangement 106. The control system may provide at least one (electrical) signal to the light source arrangement 106 to enable or disable the light source arrangement 106 and/or control (or vary) the generation of the illumination light 114a by the light source arrangement 106 in terms of the light intensity.

[0055] In various embodiments, the control system may include a light-sensitive sensor (e.g., a lux sensor). The light-sensitive sensor may detect the level or intensity of ambient light. As an example, in operation, the light-sensitive sensor may detect the intensity of ambient light. A controller or processor of the control system may receive a signal from the light-sensitive sensor corresponding to the intensity detected and compares the signal against at least one threshold level to determine whether to either switch on or off the light source arrangement 106, or to maintain the state of the light source arrangement 106. In various embodiments, in response to the intensity of ambient light that is detected by the light-sensitive sensor, the control system may adjust the intensity of the illumination light 1 14a, for example, increasing the intensity of the illumination light 1 14a when there is insufficient ambient light, or decreasing the intensity of the illumination light 114a when there is sufficient ambient light.

[0056] In various embodiments, the light collection arrangement 104 and the light guiding arrangement 102 may be operable during daytime to collect sunlight 1 12a and guide at least a portion 1 12b of the sunlight 1 12a collected for illumination of an indoor space, while the light source arrangement 106 and the light guiding arrangement 102 may be operable during nighttime (or near nighttime, e.g., dusk) to generate an illumination light 114a and guide at least a portion 114b of the illumination light 1 14a for illumination of an (the) indoor space. Where required, another portion of the illumination light 114a may be provided for illumination of an outdoor space. The OCE may be operable during daytime and nighttime. [0057] In the context of various embodiments, the lighting apparatus 100 may be free of a sun tracker device.

[0058] In the context of various embodiments, the lighting apparatus 100 may include or may be a (outdoor) lamp post.

[0059] In the context of various embodiments, the lighting apparatus 100 may be a hybrid lighting apparatus (e.g., a hybrid solar lighting lamp post or structure) capable of collecting sunlight 112a and generating an illumination light 114a for illumination of at least one of an indoor space or an outdoor space.

[0060] FIG. IB shows a flow chart 130 illustrating a method of forming a lighting apparatus, according to various embodiments.

[0061] At 132, a light guiding arrangement is provided.

[0062] At 134, a light collection arrangement adapted to collect sunlight is provided, and the light guiding arrangement is arranged to be optically coupled to the light collection arrangement to receive at least a portion of the sunlight collected for propagation through the light guiding arrangement.

[0063] At 136, a light source arrangement configured to generate an illumination light is provided, and the light guiding arrangement is arranged to be optically coupled to the light source arrangement to receive at least a portion of the illumination light for propagation through the light guiding arrangement.

[0064] FIG. 1C shows a flow chart 140 illustrating a method of forming a lighting apparatus, according to various embodiments.

[0065] At 142, a light guiding arrangement is arranged to be optically coupled to a light collection arrangement adapted to collect sunlight so as to receive at least a portion of the sunlight collected for propagation through the light guiding arrangement.

[0066] At 144, the light guiding arrangement is arranged to be optically coupled to a light source arrangement configured to generate an illumination light so as to receive at least a portion of the illumination light for propagation through the light guiding arrangement.

[0067] It should be appreciated that descriptions in the context of the lighting apparatus 100 may correspondingly be applicable in relation to the method of forming a lighting apparatus as described in the context of the flow charts 130, 140. [0068] Various embodiments may provide a lighting lamp structure combining a light- emitting diode (LED) illumination system and a solar concentrator system for indoor or car park illumination. Various embodiments may provide a solar concentrator structure to collect the sunlight all day without using a sun-tracker. One or more solar concentrators may be provided, which may be arranged in a hemispherical or dome shape around the axis of the dome. One or more LED arrays may be mounted at the center of the lamp post. When an indoor or car park illumination is not bright enough, the LED array(s) may be turned on, e.g., automatically. The lamp structure of various embodiments not only provides illumination for indoor or car park but also for an outdoor public area.

[0069] FIG. 2 shows a schematic diagram 250 illustrating a lighting application of the lighting apparatus 200a, 200b of various embodiments. Each lighting apparatus 200a, 200b may be in the form of a lamp post and placed in a public area. Using the lighting apparatus 200a as a non-limiting example, each lighting apparatus 200a, 200b may include a housing 252 arranged at an upper part of the lighting apparatus 200a, 200b, a (vertical) support structure 254 to support the housing 252, and a base structure 256 arranged at a lower part of the lighting apparatus 200a, 200b. The housing 252 may be coupled or attached to the support structure 254. The support structure 254 may be coupled to the base structure 256, or received within a cavity (not shown) of the base structure 256. Each lighting apparatus 200a, 200b may be a hybrid solar lighting lamp apparatus or system that may be built on the ground (or at ground level) 280 so that maintenance is easily accessible.

[0070] Using the lighting apparatus 200a as a non-limiting example, each lighting apparatus 200a, 200b may include three parts: a light collection arrangement or system 204, one or more optical fibers 260 and a light distribution arrangement or system 262. The light collection arrangement 204 may be arranged within the housing 252.

[0071] The light collection system 204 may include one or more solar concentrators (e.g., see FIG. 3A - 305a, 305b to be described later below), which may refract sunlight or rays from the sun 262 into an optical coupling element (OCE) (e.g., see FIG. 3 A - 308 to be described later below) and then transmitted to the desired position by the optical fiber(s) 260 for illumination of an area or space, for example, an underground space (e.g., car park) 264. The optical fiber(s) 260 may run through the support structure 254 and the base structure 256. The optical fiber(s) 260 may extend out of the base structure 256 to the underground space 264. The light distribution arrangement 262 is optically coupled to the optical fiber(s) 260 to provide a large area illumination distribution 266 to illuminate the underground space 264.

[0072] In known solar concentrators or solar lighting devices, a sun-tracker is used to calculate the exact position of the sun and then the solar concentrators are mechanically positioned or moved to capture the most solar radiation through the day. There is the possibility of the sun-tracker breaking down mechanically. This potentially leads to a decrease in lighting performance.

[0073] FIG. 3A shows a schematic cross sectional view of a lighting apparatus 300, according to various embodiments. The lighting apparatus 300 may include a housing 352 supported by a support structure 354 and a base structure 356 that is positioned on the ground. As illustrated in FIG. 3A, the lighting apparatus 300 may be a lamp post.

[0074] The lighting apparatus 300 may be a hybrid solar lighting lamp system without a sun-tracker. The lighting apparatus 300 may employ a plurality of solar concentrators (two solar concentrators represented as 305a, 305b), a light emitting diode (LED) module or fixture 307, an OCE 308 and one or more optical fibers (or fiber bundles) 360. The custom designed concentrators 305a, 305b may be placed at the top portion of the lamp post 300. The light emitting diode (LED) module 307 may be supported on a carrier structure 358 which may be optically transparent.

[0075] The LED fixture 307 may include at least one LED, one or more TIR lens and a driver, to provide indoor illumination when the brightness is insufficient, and which may also be used to illuminate a vicinity of outdoor public area. Therefore, the LED fixture 307 may act as a light source arrangement. The OCE 308 is a device that may be located at the focal point of the respective solar concentrator 305a, 305b to couple sunlight collected by the solar concentrator 305 a, 305b to the optical fiber(s) 360. Moreover, the use of the OCE 308 may enable the collection angle to be increased. Such a design does not take up additional space (e.g., on a roof garden) and it may prevent vandalism in public. As described above, therefore, the lighting apparatus 300 may be a lamp post combined with LED(s) and solar concentrators 305a, 305b.

[0076] FIG. 3B shows a schematic top view of the lighting apparatus (e.g., lamp post) 300. The LED fixture 307, which may include one or more LED arrays, may be positioned at a central part of the lamp post 300. The LED fixture 307 may be surrounded by solar concentrators 305a, 305b, 305c, 305d, 305e, 305f. As such, the LED fixture 307 may be located at the center of an arrangement of solar concentrators 305a, 305b, 305c, 305d, 305e, 305f. The LED fixture 307 may include LEDs integrated with sensor and control driver.

[0077] As a non-limiting example, as shown in FIG. 3B, each unit of the lighting apparatus (or hybrid solar lighting lamp system) 300 may include six solar concentrators 305a, 305b, 305c, 305d, 305e, 305f and one LED module 307. However, it should be appreciated that the number of solar concentrators and/or LED module may vary for different embodiments.

[0078] The angle between two solar concentrators, e.g., 305a, 305c, may be about 12 degrees (12°) so as to minimise or avoid interference (for example, please refer to FIG. 3B). Each solar concentrator 305a, 305b, 305c, 305d, 305e, 305f may be associated or equipped with an optical fiber 360. All of the fibers 360 may be combined to a single cable at the exit position.

[0079] FIGS. 4 A and 4B show schematic cross sectional views illustrating a lighting application of the lighting apparatus 300 at different times of the day, showing a non- limiting example application of the solar concentrators 305a, 305b for indoor illumination in the morning and in the afternoon. As would be appreciated, the position of the sun relative to the lighting apparatus 300 varies through the daytime.

[0080] As shown in FIG. 4A, during daytime with a morning sun 462a, one or more solar concentrators, e.g., 305a, may collect the sunlight 412a from the sun 462a and converge the rays 412a into the OCE 308. In this way, the OCE 308 may receive converged or focused sunlight rays 412b. During daytime with an afternoon sun 462b, one or more solar concentrators, e.g., 305b, may collect the sunlight 413a from the sun 462b and converge the rays 413a into the OCE 308. In this way, the OCE 308 may receive converged or focused sunlight rays 413b. The rays 412b, 413b received by the OCE 308 may be optically coupled or distributed to the optical fiber(s) 360, for example, to be transmitted onwards for indoor or underground illumination.

[0081] If the sunlight 412a, 413a is not sufficiently bright, e.g., during cloudy/rainy days, a sensor of the lighting apparatus 300 sends a signal to an LED compensation system (e.g., see FIG. 7 to be described later below) to switch on the LED(s) and adjust the brightness to achieve the desired light level for illumination of a space such as an indoor/underground space. This design, for example, may be able to maintain at least a minimum light level at the indoor/underground space. This may be desirable as a great and sudden change of luminance may cause psychological impacts such as fright or trauma.

[0082] FIG. 5 shows a schematic cross sectional view illustrating a lighting application of the lighting apparatus 300 after sunset (e.g., during nighttime), showing a non-limiting example application of the lamp post 300 for outdoor public area and indoor illumination. As or when the sun sets and/or during nighttime, the LED(s) of the LED fixture 307 providing illumination light may be switched on (e.g., fully on) providing ambience lighting 514 to the outdoor public area as well as input light 515 to the OCE 308 required for transmission to the end point light distribution arrangement or luminaire via the optical fiber(s) 360 to an indoor area.

[0083] In various embodiments, the optical coupling element (OCE) of the lighting apparatus may be movable. During the time when the sunlight is insufficient to provide the desired indoor illumination and the LED may not be required to provide lighting to an outdoor public area, as shown in FIG. 6, the LED(s) of the LED fixture 307 of a lighting apparatus 600 may be turned on partially or fully, and the OCE 608 may move up to collect at least substantially all of the light rays 614 from the LED. A lamp post 600 using a movable OCE 608 may be helpful for illuminating an indoor environment when the sun is just coming up (e.g., dawn) or setting (e.g., dusk). Making use of such an approach may enable such a design to achieve approximate 100% energy efficiency.

[0084] FIG. 7 shows a schematic block diagram 770 illustrating a compensation control scheme (e.g., an LED illumination compensation control scheme), according to various embodiments. As a non-limiting example, FIG. 7 shows a smart LED compensation control scheme which includes one or more light sensors 772 that are used for detecting the light intensity from sunlight 712.

[0085] Sometimes, there is not enough sunlight in the evening or during a cloudy day and, also, the solar radiation intensity may vary during the daytime. Therefore, in various embodiments, LED lighting may be designed to compensate the brightness if the sunlight is insufficient. The advantage of the LED compensation system is not just for providing light at an indoor/underground space but also for providing ambience lighting above ground for safety and security reasons. A smart LED compensation system may be designed with one or more sensors to perform this task. Light intensity may be detected by a lux sensor 772. A controller (e.g., a micro-computer (MCU) controller) 774 receives a signal from the sensor 772 corresponding to the detected light intensity and compares it to at least one threshold level (optionally two or more thresholds) to turn on or off the LED(s) 776. One or more lux sensors 772 may be installed on top of the solar concentrator of a lighting appratus and/or at an indoor/underground space. Since the distance from the sensor 772 to the controller 774 is short, sensors with a digital interface may be used. The micro-computer (MCU) controller 774 may be interfaced with the lux sensor(s) 772 to dim down or brighten the LED light. The micro-controller unit (MCU) 774 may include an analog-to-digital converter (ADC) 790, an inter-integrated circuit (I2C) 792, a software (SW) module 794, and a general-purpose input/output (GPIO) 796.

[0086] While the invention has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.