FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
PROVISIONAL SPECIFICATION (See section 10 and rule 13)
TITLE OF THE INVENTION
A method of manufacturing and designing reflective surface of a light reflector
APPLICANTS
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400030,
Maharashtra, India, an Indian Company
Inventors
Kumar Kapil of Crompton Greaves Ltd, Lighting Division, Crompton Greaves Limited, Kanjurmarg (East) Mumbai-400042, Maharashtra India, an Indian National

PREAMBLE TO THE DESCRIPTION
The following specification describes the invention


The present invention relates generally to a method of manufacturing reflective surface of luminaries.
In the known luminaries the light-directing element is a reflective surface of a concavely shaped reflector, the light source being arranged on an optical axis of the reflector. The shape of the reflective surface is calculated with an algorithm and is thus optimized with respect to coupling light into a light entrance surface of an optical fiber system. The algorithm further takes into account that the luminous intensity has to be constant as much as possible across the light entrance surface of the optical fiber system. Thus a highly efficient light output of the system is obtained. However, it was found that the known luminaries still has as a disadvantage that the algorithm used does not yield an optimized shape for the reflective surface for the accommodated light sources. As a result the efficiency and uniformity of the known luminaries is not optimal for the accommodated light sources.
Further, the process of designing the reflective surface of luminaries is done with hit and trial method. This results in taking much time and human effort to reach up to the precised level of reflective surface of the reflector. To overcome these drawbacks, a method of manufacturing the reflective surface of a reflector is disclosed herein.
An object of the invention is to provide a system and method for reflector designing, this can be achieved without hit and trial method.
An object of the invention is to provide a system and method for reflector designing,
2 '31 MAR 2009

which can help in achieving the desired intensity of the luminaries.
An object of the invention is to provide a system and method for reflector designing, which can help in achieving the desired polar curve for the reflector.
An object of the invention is to provide a system and method for reflector designing, which can be cost effective as in the traditional method the major expenses takes place at the time of reflector designing.
An object of the invention is to provide a system and method for reflector designing, Which can be efficient aime mrre saving terra3 the desinzd restift can be acnievecd ra a day or two.
An object of the invention is to provide a system and method for reflector designing, which can give independence to the creator to vary the aesthetics of the luminaries depending on the requirements.
Stepl
Data collection
In accordance with the invention, for designing a reflector, following details can be required such as but not limited to, bare lamp photometric data, desired photometric data, and desired cut off angle. The light emitting out from the source (lamp) can be classified as direct light, indirect light and total light. Direct light tan be the light falling directly from the bare lamp to object, indirect light can be the light falling on the object after
3
3 1 MAR 2009

being reflected by the reflector. The total light can be the sum of both direct and indirect light. The light falling of the task can be calculated as indirect flux, direct flux and total beam flux.
Step 2
Indirect flux calculation
In accordance with the invention, to simply the calculation the polar diagram of the lamp can be divided into two halves.
In accordance with the invention, a range of zonal angle with a predefined interval can be decided depending upon the require precision of graph. To achieve precision, the interval between the two zonal angles can be minimal and the range should be maximum. Based on the range of zonal angle, a midzone angle can be decided. Depending on the positioning of the zonal angle and mid zone angle on the graph, a midzone of luminous intensity and zonal intensity (lumen/candela) can be calculated. The zonal flux can be calculated by multiplying the midzone luminous intensity and zonal intensity (lumen/candela is the unit of zonal intensity). The cumulative flux can be calculated by summation of all the zonal flux calculated for each midzone angle. Based on the cumulative flux, a flux percentage can be calculated.
In accordance to the invention, the same method can be used for calculating indirect flux for other half also.
3 1 MAR 2fl09

Step 3
Direct flux calculation
In accordance with the invention, a range of zonal angle with a predefined interval can be decided depending upon the require precision of graph. To achieve precision, the interval between the two zonal angles can be minimal and the range should be maximum. Based on the range of zonal angle, a midzone angle can be decided. Depending on the positioning of the zonal angle and mid zone angle on the graph, a midzone luminous intensity and zonal intensity (lumen/candela) can be calculated. The zonal flux can be calculated by multiplying the midzone luminous intensity and zonal intensity (lumen/candela). The cumulative flux can be calculated by summation of all the zonal frax ca\c\nated for each midzone angte. Based on the cumulative feom, -a ftm pwrerAage; can be calculated
In accordance to the invention, the same method can be used for calculating direct flux for other half also.
Step 4
Total Beam flux calculation
In accordance with the invention, a range of zonal angle with a predefined interval can be decided depending upon the require precision of graph. To achieve precision, the interval between the two zonal angles can be minimal and the range should be maximum. Based on the range of zonal angle, a midzone angle can be decided. Depending on the positioning of the zonal angle and mid zone angle on the graph, a midzone luminous
5 '31 MAR 2009

intensity and zonal intensity (lumen/candela) can be calculated. The midzone luminous intensity can be multiplied by a scattering coefficient, whose value may vary depending upon the atmosphere in which the reflection takes place. The scattering coefficient is the medium or the factor of the atmosphere/nature in which the light is scattered before traveling or reflecting. Due to the factor, a small amount of light is lost before getting reflected. During the calculation of total beam flux that amount can also be added in a form of coefficient. The zonal flux can be calculated by multiplying the midzone luminous intensity and zonal intensity (lumen/candela). The cumulative flux can be calculated by summation of all the zonal flux calculated for each midzone angle. The value of the cumulative flux can be calculated after calculating the value the scattering coefficient.
In accordance to the invention, the value of scattering coefficient can be calculated by the following equation-Total Beam flux X Scattering factor = Direct flux + (Indirect flux X Reflective Index) In accordance to the invention, the same method can be used for calculating total beam flux for other half also.
Step 5
Plotting of graph
In accordance with the invention, after the calculation of both direct flux and indirect flux, both are tabulated against percentages. Now for every value of indirect flux corresponding value of direct flux is marked. This can be done by plotting direct flux
6
3 1 MAR 2009

angle on one axis and indirect flux angle on other.
Step 6
Tracing reflector curve
In accordance with the invention, a reflector curve can be traced by the conventional ray
tracing method.
In this method the above calculated values of corresponding direct and indirect flux
angles are plotted. The perpendicular to the bisector of the above angles is the tangent to
the reflector profile. These points are collected by this method are traced to get a reflector
7 31 MAR 2009
profile.