Patent Application
20080094819
The invention generally relates to a lighting device, more specifically to a lighting device for providing isometric rotating light beam of a high intensity from semiconductor lighting elements, like LEDs, whose light emission is directional in nature. that can be used in aviation industry, obstacle beacons etc., still more precisely the present invention relates to a semiconductor lighting device with capabilities of detecting failures in the device.
In many situations there is a need for providing a light beam, which may be flashing and can be viewed from—many or all directions. For example, in aviation industry the visibility of the lighting—devices placed on top of a high rising obstacle is expected to be independent of—direction of observation. This is highly desirable to protect huge loss of life and property. Similarly lighthouses, buoys, etc. provide signals to ships in all directions and stages in auditoriums have high intensity lights, which move.
The existing technology for lighting devices—mainly depends on the lighting elements—like bulb or halogen etc., however, these lighting elements consume a large amount of power and are very expensive to maintain. The development of other lighting elements, like Light Emitting Diodes (LEDs), lasers, quantum dots. etc. have offered an alternate cost effective solution. However, the implementation of a lighting device—using LEDs for the aforesaid task is difficult due to various constraints associated with the LEDs, like directional nature of light, and the demanding specifications and expectations from the lighting devices.
For applications like aviation and navigation, not only uniform visibility from all the directions is desired but also the intensity of light at various angles is required to be according to a predefined specification by International Organizations, like International Civil Aviation Organisation (ICAO), International Maritime Board, etc.
The existing technologies using LEDs are not able to meet the above-mentioned requirements simultaneously. For example, one of the lighting devices—shown in
Therefore, it has been observed that there is a need of a device to avoid all above and other limitations. A lighting device, visible from all the directions, is required which has tunable light intensity and preset viewing angle. Further there is a need of a lighting device that uses few components to increase reliability providing a cost-effective, low power and lightweight solution. Since such light sources are installed in remote and sometimes not easily accessible places, the lighting device should be highly reliable and capable of giving alarms local and/or distant, on sensing failure. Further, ease of operating such lights from solar energy is also desirable.
It is an object of the invention to provide a light beam using semiconductor light sources, like LEDs that is visible from various angles and directions.
It is yet another object of the invention to provide a lighting device—that has tunable light intensity and a preset viewing angle.
It is yet a further object of the invention to provide a lighting device—that can detect partial failures within itself.
It is yet another object of the invention to provide a lighting source that can indicate failure and activate alarms before a complete failure takes place.
Still another object of the invention is to provide a lighting device, which can run directly with the help of a solar panel connected to a battery.
To achieve the aforementioned and other objects the present invention provides a lighting device comprising one or more semiconductor light-sources for generating a light beam, at least a motor for rotating said light beam, and a controller for controlling speed of rotation of the motor and intensity of the light-source and monitoring the operating conditions. The light beam is rotated either by using a stationary light-source and rotating reflector or, stationary reflector and rotating light-source or any combination thereof.
The semiconductor light-source includes one or more lighting elements. The lighting elements are LED(s) and/or, laser diodes and/or, quantum dots. These lighting elements are provided with a focusing arrangement for focusing the light in a direction and are mounted on a mount. This mount includes PCBs and metal plates, preferably an aluminum plate, for sinking heat. The intensity of the light generated by the elements ranges at least in the domain of 150-500,000 Candela.
The light-source can be provided with a reflector for reflecting the light beam generated by the light-source. Motor(s) is/are used to rotate the generated light beam(s) by rotating either the light-source and/or, a reflector or, any such combination. The rotation speed of the motor is adjustable and may be varied according to the requirements. At different rotating speeds the light beam simulates either a flashing or a continuous beam of light. Motor(s) and lighting-source(s) are covered in a covering. This covering can be a polycarbonate, it provides rigidity and water proofing to the device.
A controller is used to control operation of the lighting device. The controller is either a microprocessor and/or microcontroller and can be programmed from a remote location. Controller is coupled with motor and light-source to control the speed of rotation of the motor and the intensity of light in the lighting device. Controller is coupled to the light-source through semiconductor switch which can be a MOSFET or BJT etc. The controller is configured to monitor functioning of the light-source and maintain the light intensity at a desirable level. Controller is provided with a current sensor also. This current sensor monitors current through the light-source and helps in detecting partial and/or, full failure of the light-source/lighting elements. An audio and/or, visual indicator and/or, radio or, telecom equipment using land and/or, air and/or, satellite links is also coupled to the controller for failure indication. In case of failure of any lighting element(s), the controller distributes current flow in the remaining semiconductor light-source and/or, lighting element(s) to maintain desired intensity of light emitted from the source. For its effective working of the lighting device controller is further provided with sensors for sensing temperature, current through semiconductor light-source, motor failure, light intensity, the whole assembly being stationary or rotating, and other necessary operating condition.
This lighting device can be powered by non-conventional or conventional power supply. The conventional power supply can be an AC to DC and/or, DC to DC power supply. The light-source(s) of the lighting device are switched ON using a light dependent sensor, like solar panel, light dependent resistor, photo diode, etc. and/or, a timer.
This lighting device can be used for aviation, navigation, stage lighting or other purposes. It could consist of a light-source focused in one direction and rotating.
These and other aspects of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings in which like designations are used to designate substantially identical elements.
A further understanding of the present invention may be obtained with reference to the following description taken in conjunction with the accompanying drawings. However, the embodiments used for describing the invention are illustrative only and no way limiting scope of the invention. A person skilled in the art will appreciate that many more embodiments of the invention are possible without deviating from the basic concept of the invention any such embodiment will fall under the scope of the invention and is a subject matter of protection.
In the following description light-source is one or more lighting elements mounted on a metal plate where lighting elements are either LED(s) and/or laser diodes and/or quantum dots.
Lighting device defines an assembly of light-source coupled with a motor and both light-source and motor are controlled by a controller.
The controller 115 senses temperature, current through semiconductor flashing device, motor failure, light intensity, the whole assembly being stationary or, rotating and other necessary operating condition of the devices for effective working of the lighting device. Controller is configured to sense functioning of the light-source(s) with the help of current sensor(s). The controller is provided with a detector for detecting partial or, full failure of the light-source and an indicator 200 for indicating failure. In case of failure or any lighting element(s) the controller detects the malfunctioning and distributes current flow in the remaining light source(s) and/or, lighting element(s) to maintain desired intensity of light emitted from the device. In case current flow distribution in remaining lighting element(s) exceed their continuous current rating, the failure of lighting elements is signaled by a light and/or, an alarm at the failure indicator 200 to avoid continuous higher flow of current through the remaining lighting element(s). Speed of motor is also controlled depending on the number of flashes.
One of the possible working models of product flowing out of the invention is described in FIGS. 2 to 4.
The optical arrangement is depicted in
The invention further provides multiple parallel redundant power supplies, option of solar powering the device for the electronics, including for LEDs, and the stepper motor. The LEDs of the light source of the invention is also provided with a controlled current to ensure that heating is reduced and the life of LED is increased.
In case of failure of one or more LEDs, the invention provides provisions for increasing illumination of one or more LEDs, thereby maintaining the intensity. Further, in case of multiple failures, beyond a stage when the current flowing through the LEDs increases beyond their continuous current rating, the electronics used makes the LED flash thereby providing the visual failure indication. The flashing also ensures that the LED life is not reduced because of higher current flow through it.
The rotation of the motor can be varied by the user depending on the number of flashes required per minute, which should be adjustable with a remote. The motor could also vary the angle as is required by the entertainment industry. To drive the motor, to monitor the motor, to switch on power supply and to flash LEDs, various types of controls and alarms are required which are best implemented using a microcontroller. The microcontroller takes care of a situation where a motor may resonate and ensures that the motor is actually rotating at the speed set by the remote and gives an early warning when failure is sensed. There may be some variation in the motor parameters from piece to piece while settings for alarms may also be varied. Such parameters can be changed through remote.
Further, the invention also proposes usage of one or more plates of LEDs according to the frequency of flashing and angles. In addition, a constantly ON light source may also be designed by altering the frequency (by changing motor parameters or providing additional plates) accordingly. Such signals may be mounted at heights of over 100 mts where they could be subjected to high winds. It has also been found that the high intensity LEDs generate a certain amount of heat for which they are to be mounted on heat sinks exposed to the atmosphere. Since the lights are installed at heights, weight is also important. Accordingly the weight is drastically reduced in comparison to similar available products. Further the motor and internal circuitry needs a waterproof enclosure. The effect of wind, on the motor may be discounted, when generating alarms. The alarm may also be set off without a wired connection at a distant location.
In some cases it is possible that more than one such light will be installed and synchronized so that the lights are visible in the same direction at the same time. The alarms should be such that the technician is able to identify the light, which is defective by looking at it. The product may also be run from solar power and would have provision for protecting it from lightening.
The light assembly broadly finds application in aviation industry, obstacle beacons, lighthouses and entertainment industry.
Since the lighting device may be fixed in the open, on high rise structures, it may be water and dust proof and may be accompanied with lightening arrestor(s) to protect it from lightening strikes.
It may also be possible to achieve the above benefits by having a stationary light source with a rotating mirror mounted at an angle of say 45 degrees to reflect the light so as to further optimize the power consumption.
| Number | Date | Country | Kind |
|---|---|---|---|
| 292/DEL/2005 | Feb 2005 | IN | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IN06/00046 | 2/10/2006 | WO | 8/10/2007 |
