FORM 2
THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13) 1. Title of the invention: GEMSTONE ALIGNMENT FOR LASER CUTTING
2. Applicant(s)
NAME NATIONALITY ADDRESS
SAHAJANAND Indian Sahajanand Estate, Wakharia Wadi,
TECHNOLOGIES PRIVATE Near Dabholi Char Rasta, Ved
LIMITED Road, Surat-395004, Gujarat, India
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it
is to be performed.

TECHNICAL FIELD
[0001] The present subject matter relates, in general, to gemstone processing,
and particularly to laser cutting of gemstones.
BACKGROUND
[0002] Laser cutting is a process of cutting a material according to a design or
a shape. In a laser cutting process, a laser beam from a high-powered laser source is focused to create a spot beam on the material. The spot beam cuts the material either by burning or by melting or by vaporization. The spot beam cuts the material very precisely due to which the laser cutting process is used in variety of industrial manufacturing applications. One such industrial manufacturing application is gemstone cutting. Gemstones can be diamonds or any precious or semi-precious stones.
BRIEF DESCRIPTION OF DRAWINGS
[0003] The features, aspects, and advantages of the subject matter will be
better understood with regard to the following description, and accompanying
figures. The use of the same reference numeral in different figures indicates
similar or identical features and components.
[0004] Fig. 1 illustrates a gemstone processing system, in accordance with an
implementation of the present subject matter.
[0005] Figs. 2(a) – 2(e) illustrates various stages of a method performed by
the gemstone processing system for aligning a gemstone before performing the
gemstone cutting operation, in accordance with an implementation of the present
subject matter.
[0006] Fig. 3 illustrates a method of aligning the gemstone, in accordance
with an implementation of the present subject matter.

DETAILED DESCRIPTION
[0007] A rough gemstone is processed into a finished gemstone by enhancing
the properties of the rough gemstone. The process for enhancing the properties of
the rough gemstone includes cutting, faceting, shaping, and polishing.
[0008] For cutting a gemstone, the gemstone is generally placed on a rotation
table. A laser beam from a laser source is focused on the gemstone. A computerized numeric controller (CNC) controls the process of cutting the gemstone. The CNC provides commands to operate the laser, the rotation table and other machining components that assists in cutting of the gemstone. The commands provided by the CNC is based on a cutting profile that describes a shape in which the gemstone is to be cut. The commands from the CNC to the laser control the focusing of the laser beam on the gemstone, and the commands from the CNC to the rotation table control the movement of the gemstone during the cutting process.
[0009] For precise cutting of the gemstone, the gemstone has to be properly
positioned on the rotation table before initiation of the gemstone cutting process. Generally, CNC does not have intelligence to identify exact positioning of the rotation table and the gemstone placed on the rotation table. Therefore, the gemstone has to be manually positioned and aligned on the rotation table. The manual alignment of the gemstone on the rotation table is perceivable by a visual inspection of a person aligning the gemstone.
[0010] Correct alignment of the gemstone is critical to the gemstone cutting
process. Any error in the alignment may result in an improper cutting of the gemstone. Also, the CNC may drive the machining components outside the cutting area if the alignment is not correct. Improper cutting of the gemstone may result in scrapping of the gemstone and may lead to wastage. Further, manually alignment of a gemstone is laborious and time consuming. The efforts and time consumed are enhanced when a small-sized gemstone is aligned on the rotation table because inspecting the alignment of the small sized gemstone on the rotation table is rather more difficult.

[0011] The present subject matter describes alignment of a gemstone before
performing a laser cutting operation on the gemstone. Methods and systems of the present subject matter for alignment of the gemstone facilitate correct and efficient alignment of the gemstone before performing the laser cutting operation of the gemstone. The methods and the systems of the present subject matter enable automatic alignment of the gemstone.
[0012] The gemstone aligning system based on the present subject matter
rotationally aligns the gemstone along an axis and thereafter, translates the
gemstone linearly along the axis to place the gemstone in correct position.
[0013] In accordance with an implementation of the present subject matter,
the gemstone is positioned on a rotation table of a gemstone processing system.
For correct positioning and alignment of the gemstone, a reference mark on the
gemstone should be known through which the center of the gemstone can be
detected. Further, the reference mark should overlap a rotation center of the
rotation table in order to determine that the gemstone is correctly positioned and
aligned. The rotation center is a position at a center of the rotation table about
which the rotation table is rotated. For aligning the gemstone, the center on the
gemstone is detected and the position of the reference mark with respect to the
rotation center of the rotation table is determined. The position of the reference
mark, with respect to the rotation center, is determined in terms of an angle, where
the angle is formed by a straight line joining the rotation center and the reference
mark with respect to a principal axis, i.e. either X-axis or Y-axis of the rotation
table. If the position of the reference mark is away from the rotation center, then
the angle is determined to be non-zero. The rotation table is rotated around the
rotation center by the angle to bring the reference mark on the principal axis.
[0014] In one example, when the position of the reference-mark is determined
to be on the principal axis, such as X-axis, the gemstone is pushed along the X-axis and towards the rotation center, for example, by a predetermined distance. After pushing the gemstone towards the rotation center by the predetermined distance, position of the reference-mark is determined for any deviation in upward or downward direction from the X-axis. If any deviation is determined, the angle

is again determined for rotating the rotation table by the newly determined angle, for repositioning the reference-mark back on the X-axis. The gemstone is again pushed towards the rotation center by the predetermined distance and deviation from the X-axis is determined. The gemstone is pushed along the X-axis and towards the rotation center and the deviation from the X-axis is determined until the reference-mark overlaps the rotation center.
[0015] The methods and the systems of the present subject matter
automatically aligns the gemstone on the rotation table accurately and efficiently
before the initiation of the gemstone cutting. This leads to production efficiency.
Further, the alignment performed by the methods and the systems of the present
subject matter eliminate any error that may result from manual alignment.
Furthermore, the alignment is monitored by the system, therefore, the gemstones
of small size may be aligned efficiently as compared to manual alignment.
[0016] The manner in which the gemstone alignment shall be implemented
has been explained in detail with respect to Fig. 1 and Fig. 2(a) - 2(e). It should be noted that the description and figures merely illustrate the principles of the present subject matter.
[0017] Fig. 1 describes a gemstone processing system 100, in accordance with
an implementation of the present subject matter. The gemstone processing system 100 aligns a gemstone 11 in accordance with the present subject matter and performs a laser cutting operation on the gemstone 11. As shown in Fig. 1, the gemstone processing system 100 includes a laser source 1, a beam orientation device 3, a beam focusing device 5, and a rotation table 6. A gemstone 11, for example a diamond, is positioned on the rotation table 6. Further, the rotation table 6 is coupled to a motor 7 through a shaft (not shown) which, when operated, rotates the rotation table 6 about a rotation center (not shown in Fig. 1) of the gemstone processing system 100. In one example, the rotation center is at a center of the rotation table 6. Further, a die 10 is mounted on the rotation table 6 to hold the gemstone 11.
[0018] The laser source 1 emits a laser beam 2 in a direction parallel to the
plane of the rotation table 6 and directs the laser beam 2 towards the beam

orientation device 3. The beam orientation device 3 reflects the laser beam 2 towards the focusing device 5. Further, the beam orientation device 3 can be a partially silvered mirror. For example, the beam orientation device 3 may be a 50:50 glass mirror that is placed at an angle of 45 degrees with respect to the plane of the rotation table 6. The focusing device 5 focuses the laser beam 2 on the gemstone 11 placed on the die 10. The laser beam reflected by the gemstone 11 passes through the beam orientation device 3 towards another beam orientation device, for example, a plane mirror 12. As shown in Fig. 1, the plane mirror 12 is positioned at an angle of 45 degrees with respect to the plane of the rotation table
6. A laser beam 4 passing through the beam orientation device 3 gets reflected by
the plane mirror 12 towards an image capturing device 8. The laser beams
directed towards the image capturing device 8 form an image of the gemstone 11,
positioned on the rotation table 6, at the image capturing device 8.
[0019] The gemstone processing system 100 further includes a controller 14.
The controller 14, as shown, is coupled to the image capturing device 8, the motor
7, and a linear actuator 9. The linear actuator 9 is positioned to move the die 10 in
a single direction, for example, along X-axis with respect to the rotation center of
the rotation table 6. The controller 14 receives and processes signals from the
image capturing device 8 to determine the position of the reference-mark on the
gemstone 11 with respect to the rotation center of the rotation table 6 and
accordingly provides commands to operate the motor 7 and the linear actuator 9
for aligning the gemstone 11. The controller 14, as shown, is also coupled to the
laser source 1 to operate the laser source 1.
[0020] The controller 14 includes processor(s) which may be implemented as
microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. Among other capabilities, the processor(s) may fetch and execute computer-readable instructions stored in a memory (not shown) coupled to the processor(s) of the controller 14. The memory may include any non-transitory computer-readable storage medium including, for example, volatile memory (e.g., RAM), and/or non-volatile memory (e.g.,

EPROM, flash memory, NVRAM, memristor, etc.). The memory may be internal or external to the controller 14. The functions of the controller 14 may be provided through the use of dedicated hardware as well as hardware capable of executing computer-readable instructions.
[0021] An example procedure to align the gemstone 11 on the rotation table 6 of the gemstone processing system 100 is described hereinafter. The procedure is described with reference to Figs. 2(a) to 2(e) that illustrate various stages of procedure performed by the gemstone processing system 100 for aligning the gemstone 11 before performing the gemstone cutting operation, in accordance with an implementation of the present subject matter.
[0022] In operation, the gemstone 11 with a reference-mark (x) and to be aligned is placed on the die 10 of the gemstone processing system 100. Thereafter, the image capturing device 8 captures image of the gemstone 11 placed on the die 10 based on the laser beams 2 and 4. The controller 14 then processes the image captured by the image capturing device 8 to determine the reference-mark on the gemstone 11 and also determine the position of the reference-mark with respect to the rotation center of the rotation table 6.
[0023] Consider a case where the controller 14 determines that the reference-mark is away from the rotation center and the straight line from the rotation center to the reference-mark makes an angle θ with the X-axis of the rotation table 6, as shown in Fig. 2(a). The controller 14, upon determining the angle θ, provides a command to the motor 7 to rotate the rotation table 6 by the angle θ towards the X-axis. As a result, the gemstone 11 on the die 10 is rotated around the rotation center such that the reference-mark of the gemstone 11 gets positioned over the X-axis, as shown in Fig. 2(b).
[0024] Thereafter, the controller 14 provides a command to the linear actuator 9 to linearly translate the die 10 by a predetermined distance along the X axis towards the rotation center of the rotation table 6, as shown in Fig. 2(c). During the movement of the die 10 towards the rotation center of the rotation table 6, the gemstone 11 and the reference-mark may deviate from the X-axis, as shown in Fig. 2(c). The controller 14 may determine any deviation of the reference-mark

from the X-axis, based on the images captured by the image capturing device 8 during the movement of the die 10. If the controller 14 determines any deviation of the reference-mark from the X-axis, the controller 14 provides a command to the linear actuator 9 to move back, i.e. away from the rotation center along the X-axis, by the predetermined distance. In one example, the deviation may occur due vibrations caused by the movement of various component inside the gemstone processing system 100. Such vibrations can disturb the position of the gemstone 11 on the rotation table 6. Once the deviation is detected, the controller 14 determines the angle based on the amount of deviation, and provides a command to the motor 7 to rotate the rotation table 6 by that angle, such that the reference-mark is repositioned on the X-axis.
[0025] The controller 14 repeatedly provides a command to the linear actuator
9 to push the die 10 by the predetermined distance towards the rotation center of the rotation table and checks for any deviation during the movement of the die 10, as shown in Fig. 2(d), until the reference-mark overlaps the rotation center, as shown in Fig. 2(e). Once the gemstone 11 is aligned, the controller 14 may provide a command to switch ON the laser source 1.
[0001] The present subject matter also relates to a method 300 for aligning the
gemstone 11 on the gemstone processing system 100. Further, the method 300 can be executed by the controller 14 which is coupled to the memory which stores executable instructions. The exemplary method may be described in the general context of computer executable instructions embodied on a computer-readable medium. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, functions, etc., which perform particular functions or implement particular abstract data types. The method may also be practiced in a distributed computing environment where functions are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, computer executable instructions may be located in both local and remote computer storage media, including memory storage devices.

[0026] The order in which the method is described is not intended to be
construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method, or an alternative method. Additionally, individual blocks may be deleted from the method without departing from the spirit and scope of the methods, systems and devices described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.
[0027] Referring to method 300, at block 302, the gemstone 11 is placed and
the controller 14 instructs the image capturing device 8 to capture an image of the gemstone placed on the rotation table 6. In one example, the captured image includes an image of marking on the gemstone 11. Further, the captured image is transmitted to the controller 14 for further analysis.
[0028] At block 304, the captured image is analyzed to determine a position
of the marking with respect to the rotation center of the rotation table 6. In one example, the controller 14 may apply various image processing techniques known in the art to identify the marking on the gemstone and the rotation center of the rotation table 6. As shown in Fig. 2 (a), the marking and the rotation center are identified as individual dots in the captured image. Thereafter, the controller 14 checks if the marking and the rotation center are aligned. In one example, the marking and the rotation center are said to be aligned when the two overlap each other and the captured image has a single dot. If the controller 14 finds that the image has two dots, the controller 14 determines the position of the marking with respect to the rotation center. As mentioned previously, the position is determined in terms of the angle that a straight line, originating from the rotation center of the table and passing through the marking, makes with the X-axis. In one example, the angle can be determined by trigonometric transformation.
[0029] Once the angle is determined, at block 306, the gemstone 11 is rotated
so as to align the marking the axis. The gemstone 11 is aligned with the axis so as to simplify the aligning operation since aligning the gemstone along any axis would reduce the number of movement to be imparted to the gemstone 11. In one example, the controller 14 operates the rotation table 6 to provide rotation to the

gemstone 11 towards the X-axis. As may be understood, rotation of the gemstone 11 reduces the angle. While the gemstone 11 is rotated, the image capturing device 8 captures the images and relays the captured image to the controller 14. The controller 14, during the entire operation, the controller 14 constantly analyzes the image and measures the angle to constantly monitor the reduction in the angle. Once the controller 14 determines the marking is aligned with the X-axis i.e. the angle reduces to 0 degrees, the controller 14 stop further rotation of the . At this point, the gemstone 11 is positioned such that the gemstone 11 may be imparted motion along one dimension without having the gemstone 11 to move with respect to another dimension simultaneously.
[0030] At block 308, the gemstone 11 is translated linearly towards the
rotation center. In one example, the controller 14 operates the actuator 9 to
translate the gemstone 11 along the X-axis towards the rotation center by the
predetermined distance. While the actuator 9 moves the gemstone 11, the
controller 14 constantly checks for any deviation of the marking from the X-axis.
In case the controller 14 determines a deviation of the gemstone 11 from the X-
axis when the gemstone 11 was being translated by the predetermined distance,
the controller 14 operates the actuator 9 to move back in order to prevent any
interference in capturing the image. As mentioned previously, the deviation may
occur due vibrations caused by the movement of various component inside the
gemstone processing system 100. Thereafter, determines a new angle based on the
techniques explained above with respect to block 302. Thereafter, the controller
14 operates in a manner as explained in block 304. Once again aligned with
respect to the X-axis, the gemstone 11 is again moved by the actuator 9 towards
the rotation center until the marking overlaps with the rotation center as shown in
Fig. 2(e). Further, in case the linear actuator 9 has overshot the rotation center, the
controller 14 senses a distance of overshot and accordingly, the controller 14
operates the linear actuator 9 to move the gemstone back to the center.
[0031] Although the subject matter has been described with reference to
specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternate

embodiments of the subject matter, will become apparent to persons skilled in the art upon reference to the description of the subject matter. It is therefore contemplated that such modifications can be made without departing from the spirit or scope of the present subject matter as defined.

I/ We Claim:
1. A gemstone processing system (100) comprising:
a rotation table (6) to hold and rotate a gemstone (11) having a marking;
an actuator (9) to linearly translate the gemstone (11) along a principal axis;
an image capturing device (8) to capture an image of the gemstone and marking; and
a controller (14) coupled to the rotation table (6) and the image capturing device (8), wherein the controller (14) is to:
process the image to determine a position of the marking with respect to a rotation centre of the gemstone (11) processing system (100), wherein the position is determined as a measure of an angle formed by a straight line joining the rotation center and the marking with respect to the principal axis, wherein the angle is indicative of a degree of rotation to be made by the gemstone (11) to align the marking with respect to the principal axis;
rotate the rotation table (6) by the determined angle to align the marking with the principal axis; and
actuate the actuator (9) by predetermined distance along the principal axis to align the gemstone (11) with the rotation centre.
2. The gemstone processing system (100) as claimed in claim 1 further comprises motors to actuate the rotation table (6).
3. The gemstone processing system (100) as claimed in claim 1, wherein the marking is a reference mark (x).
4. The gemstone processing system (100) as claimed in claim 1, wherein the rotation table (6) includes a die to mount the gemstone (11) thereon.

5. A method for aligning a gemstone (11) including a marking with respect to
a rotation centre in a gemstone processing system (100), the method comprising:
capturing, by an image capturing device (8), an image of the marking;
processing, by a controller (14) coupled to the image capturing device (8), the image to determine a position of the marking with respect to a rotation centre of the gemstone (11) processing system (100), wherein the position is determined as a measure an angle formed by a straight line joining the rotation center and the marking with respect to a principal axis, and wherein the angle is indicative of a degree of rotation to be made by the gemstone (11) to align the marking with respect to the principal axis;
rotating, by the rotating table (6) coupled to the controller (14), the gemstone (11) by the determined angle to align the marking with the principal axis; and
translating, by a liner actuator (9) coupled to the controller (14), the gemstone (11) along the principal axis to align the marking with the rotation centre.
6. The method as claimed in claim 5, wherein the gemstone (11) processing system (100) includes motors to rotate the rotation table (6).
7. The method as claimed in claim 5, wherein the marking is a reference mark (x).
8. A controller (14) for aligning a gemstone (11) in a gemstone processing system (100), the controller (14) to:
process an image captured by an image capturing device (8) to determine a position of a marking on the gemstone (11), placed on a rotation table (6), with respect to a rotation centre of the gemstone processing system (100), wherein the position is determined as a measure of an angle formed by a straight line joining the rotation center and the marking with respect to a principal axis, wherein the

angle is indicative of a degree of rotation to be made by the gemstone (11) to align the marking with respect to the principal axis;
operate the rotating table (6) by the determined angle to align the marking with the principal axis; and
actuate a liner actuator (9) of the gemstone processing system (100) to translate the gemstone (11) along the principal axis to align the marking with the rotation centre.