CLIAMS:1. A system for optical inspection of a combustible product(s), said system comprising:
a cigarette inspection device for generating a single cigarette pulse (SCP) for said combustible product(s);
a sensor means for sensing a speed of moving said combustible product(s) on a rotatable inspection drum of a maker machine and thereby sending a speed signal to said cigarette inspection device;
at least one image capturing means for capturing an image of said combustible product(s) being conveyed on a rotatable inspection drum of a maker machine;
an image processing means processing said image obtained from said image capturing means for inspecting a defect(s) on said combustible product(s); wherein said image processing means after detecting a defect in said captured image generates reject signal;
a interfacing means for synchronizing said processing means with said cigarette inspection device; wherein said interfacing means measuring a delay between said single cigarette pulse (SCP) and said reject signal and therefore generating a synchronized reject signal which is transmitted to said cigarette inspection device;
a rejection unit being operatively connected with said cigarette inspection device for rejecting said defected combustible product(s) on receiving said synchronized reject signal.
2. The system as claimed in claim 1, wherein said cigarette inspection device provides said single cigarette pulse (SCP) to said processing means for instructing said image capturing means to capture the images of said combustible product(s).
3. The system as claimed in claim 1, wherein said interfacing means calculates speed of said maker machine and rotational distance between said rotatable inspection drum and said rejection unit, therefore generating said synchronized reject signal for rejecting said defected combustible product(s).
4. The system as claimed in claim 1, wherein said rejection unit connected inside of said maker machine for rejecting the defected combustible product(s).
5. The system as claimed in claim 1, wherein said image capturing means is a charge coupled device (CCD) camera and the like.
6. The system as claimed in claim 1, wherein said image capturing means is attached on the top of said inspection drum.
7. The system as claimed in claim 1, further comprising an illuminating means for illuminating an area in synchronization with speed of said maker machine and said image capturing means during image capturing.
8. The system as claimed in claim 7, wherein said illuminating means is a LED strobe bar.
9. The system as claimed in claim 1, said combustible product(s) selected from a group comprising a cigarette and the like.
10. The system as claimed in claim 1, wherein said interfacing means is a microcontroller.
11. The system as claimed in claim 1, wherein said cigarette making machines operates at a speed range including, but not limited to 20000 CPM.

12. A method for optical inspection of a combustible product(s), said method comprising steps of:
generating a speed signal by sensing the speed of moving said combustible product(s) on a rotatable inspection drum of a maker machine using a sensor means,
generating a single cigarette pulse (SCP) for said combustible product(s) by providing said speed signal to a cigarette inspection device,
sending said single cigarette pulse (SCP) to a processing means and a interfacing means for instructing at least one image capturing means to capture the images of said combustible product(s),
capturing the images of said combustible product(s) being conveyed on said rotatable inspection drum, of said maker machine using said image capturing means,
processing and detecting a defects in said images captured by said image capturing means using said processing means,
generating a reject signal after detecting a defect in said images captured by said image capturing means using said processing means,
measuring a delay between said single cigarette pulse (SCP) and said reject signal and therefore generating a synchronized reject signal,
transmitting said synchronized reject signal to said cigarette inspection device which transmits said synchronized reject signal to a rejection unit for rejecting said defected combustible product(s).

13. The method as claimed in claim 12, wherein said interfacing means calculates speed of said maker machine and rotational distance between said rotatable inspection drum and said rejection unit, therefore generating said synchronized reject signal for rejecting said defected combustible product(s).

14. The method as claimed in claim 12, wherein said rejection unit connected inside of said maker machine for rejecting the defected combustible product(s).

15. The method as claimed in claim 12, wherein said image capturing means charge coupled device (CCD) camera and the like.

16. The method as claimed in claim 12, wherein said image capturing means is attached on the top of said inspection drum.

17. The method as claimed in claim 12, further comprising an illuminating means for illuminating an area in synchronization with speed of said maker machine and said image capturing means during image capturing.

18. The method as claimed in claim 17, wherein said illuminating means is a LED strobe bar.

19. The method as claimed in claim 12, said combustible product(s) selected from a group comprising a cigarette and the like.

20. The method as claimed in claim 12, wherein said interfacing means is a microcontroller. ,TagSPECI:TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to an optical inspection technology for detecting defects in combustible products, preferably cigarettes. More particularly, the present invention provides an improved system and method for online detection and rejection of tipping related defects on cigarettes.
BACKGROUND AND THE PRIOR ART
Cigarettes are manufactured using high speed cigarette making machines which are typically operated at industry known speeds i.e. 3000 CPM to 20000 CPM. The finished cigarettes are inspected individually at the final inspection drum of the making machine for certain defects using different kinds of sensors and non-confirming cigarettes are rejected. Among the commonly available sensors, is the Leakage Sensor which detects the pressure drop across cigarettes leading to rejection of cigarettes with non-conforming readings. Also, present is an Optical Sensor detecting the absence of filter or tobacco at the ends of the cigarettes again leading to detection and rejection of defective product while making process is going on.
Apart from these defects, many other defect types are commonly noticed for which an online check is not provided by the Machine Suppliers. Among these defects types, the defects related to the Tipping (Printed Cork Tipping (PCT)) are most common and are being addressed using this invention. Many of the tipping related defects result into Market Complaints and upon manual detection, in order to prevent the defective product from reaching the market, large quantity of the product may have to be wasted. The said manual detection is done at a low frequency on a sample basis and therefore cannot guarantee 100% check.
At high speeds of making machine (3000 cigarettes per minute and above) both checking and rejection needs to done, hence checking for multiple defects which manifest in visual form becomes a challenge. Therefore, a Vision Camera based solution was selected as the potential value within the manufacturing industry for machine vision systems with the flexibility and acuity of human sight is widely recognized.
So far various attempts have been made to address these issues.
EP570163A2 relates to systems for Optically Inspecting Cylindrical Surfaces which uses two sets of optical cameras installed at two different drums post manufacture of the cigarette is completed. This solution uses a separately developed rejection station for the defective cigarettes which is disadvantageous, cumbersome and expensive.
JP2002148204A relates to Surface Inspecting Apparatus for Bar-Shaped Body teaches how image is being captured at two different drums from two different angles resulting into four images of each cigarette. In this case, the use of four cameras to capture images is very cumbersome and would use of lot of space in the making machine.
WO03026448A1 relates to Visual Inspection System of Rod-Like Article, used a single camera single station concept on the inspection drum. However, it is highly complex mechanism which makes modifications in the making machines drum and changes the conveyance path of the cigarette which can be highly risk prone.
JP2009171967A related to Unit for Scanning Tobacco Products of Elongated Shape Optically uses single camera system with a slit to capture the image of the cigarette for further analysis. It introduces a system to present issues in imaging which may be caused by dust flying in the area.
IN1379/KOL/2012 teaches a method of inspection to identify and quantify defect on a cigarette body and system thereof. However, this is an offline system which only checks cigarettes which are fed to it post manufacture.
US7903865B2 discloses an automatic optical inspection system which includes a rotary device for driving an object to rotate. At least one line-scan camera is implemented for generating two-dimensional planar images of cylindrical surfaces of the object. A device for detecting defects is operable to generate the two-dimensional planar images of the cylindrical surfaces of the object according to a normalized grayscale absolute difference inspection method. In this case, a line-scan camera is used which is able to scan only a line (1 pixel thick) and hence the object has to be rotated to cover the entire surface being scanned. These lines are then combined and analyzed to make a representative image of the object not an actual image per se as visible from any camera.
The objective for any vision system is to process the pixels in the image array in such a manner as to separate the object of interest from the background and the noise. Difficulty arises when a Classical Serial Computer is applied to doing operations on such a large block of data. Most popular 16 bit or 32 bit micro-computers require 10 to 15 seconds to perform a simple noise reducing filter operation. This amount of processing time is totally unacceptable for most industrial tasks. As a result, a major objective of those who have sought to deal with industrial vision problems has been to reduce or simplify the image data to enable faster processing, or go for high capacity computing resources. In recent years hardware has begun to emerge that made it possible to cost-effectively process mass data in small times that are acceptable for industrial problem solving. The challenge for the current system was that it would operate at the higher limit of the common industrial application speeds and also rejection of the defective product needs to be done with the making machine. This requires a complex synchronization operation between two different systems at high speeds.
There is a need for a system which can check all cigarettes for the targeted defects is envisioned. Therefore, present invention works by matching defined colours in the specified zones by running the image pixel data through complimenting and coordinating algorithms. The combination of the multiple algorithms being used, lead to detection of all targeted defects in the Tipping of the Cigarette.

OBJECTS OF THE INVENTION
A basic object of the present invention is to overcome the disadvantages/drawbacks of the known art.
Another object of the present invention is to provide a system for optical inspection of a combustible product(s).
Another object of the present invention is to provide a system and method having a good flexibility with respect to processing times and configuration of the algorithm used.
Another object of the present invention is to provide an improved system and method for automatically inspecting defects on a combustible product(s) in a quick and accurate way.
Another object of the present invention is to provide an improved system and method for rejecting combustible product(s) with any detected defects online on the maker machine itself.
These and other advantages of the present invention will become readily apparent from the following detailed description read in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.
According to an aspect of the present invention there is provided a system for optical inspection of a combustible product(s), said system comprising:
a cigarette inspection device for generating a single cigarette pulse (SCP) for said combustible product(s);
a sensor means for sensing a speed of moving said combustible product(s) on a rotatable inspection drum of a maker machine and thereby sending a speed signal to said cigarette inspection device;
at least one image capturing means for capturing an image of said combustible product(s) being conveyed on a rotatable inspection drum of a maker machine;
an image processing means processing said image obtained from said image capturing means for inspecting a defect(s) on said combustible product(s); wherein said image processing means after detecting a defect in said captured image generates reject signal;
a interfacing means for synchronizing said processing means with said cigarette inspection device; wherein said interfacing means measuring a delay between said single cigarette pulse (SCP) and said reject signal and therefore generating a synchronized reject signal which is transmitted to said cigarette inspection device;
a rejection unit being operatively connected with said cigarette inspection device for rejecting said defected combustible product(s) on receiving said synchronized reject signal.
Another aspect of the present invention there is provided a method for optical inspection of a combustible product(s) said method comprising steps of:
generating a speed signal by sensing the speed of moving said combustible product(s) on a rotatable inspection drum of a maker machine using a sensor means,
generating a single cigarette pulse (SCP) for said combustible product(s) by providing said speed signal to a cigarette inspection device,
sending said single cigarette pulse (SCP) to a processing means and a interfacing means for instructing a image capturing means to capture the images of said combustible product(s);
capturing the images of said combustible product(s) being conveyed on said rotatable inspection drum, of said maker machine using said image capturing means,
processing and detecting a defects in said images captured by said image capturing means using said processing means,
generating a reject signal after detecting a defect in said images captured by said image capturing means using said processing means,
measuring a delay between said single cigarette pulse (SCP) and said reject signal and therefore generating a synchronized reject signal,
transmitting said synchronized reject signal to said cigarette inspection device which transmits said synchronized reject signal to a rejection unit for rejecting said defected combustible product(s).
Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The following drawings are illustrative of particular examples for enabling methods of the present invention, are descriptive of some of the methods, and are not intended to limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.
Figure 1 illustrates a Schematic Diagram of Vision Inspection System Positioned on the High speed Maker (MAX Section)
Figure 2 illustrates an Indicative Diagram of Positioning of the Object below the Camera (1)
Figure 3 illustrates a schematic process flow chart depicting operation of the developed system
Figure 4 illustrates a cigarette with defects (A) vs. normal cigarette (B)
Figure 5 illustrates an image processing method for detecting tipping related defects
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure.
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
Accordingly, the present invention provides a system for optical inspection of a combustible product(s). The present invention, a system is provided for inspecting all cigarettes using a vision camera and image processing based system. The camera used in the present invention is charge coupled device camera (CCD) and the like.
The combustible product(s) such as, cigarettes in the making machine, post completion of all steps of manufacturing are conveyed on an Inspection Drum which also has a rejection system built into it. Presently cigarettes are made at the speeds ranging anywhere between 3,000 - 20,000 per minute and the present invention contemplates such machines which can operate at such high speeds. In the present invention, atleast one high speed CCD camera (1) with appropriate resolution and speed has been placed on top of this inspection drum. This enables a top view of the finished cigarettes being conveyed on the drum. Using a stroboscopic LED Bar Light, the area is illuminated as per the speed of the machine and camera (1) in synchronization with the machine takes images of each cigarette that is coming below it.
These images from the camera (1) are then made available by the Image Processing Computer for applying necessary Image Processing Algorithms. Multiple steps have been developed for analysis of the cigarettes including filtering of the images to remove noise and appropriate zoning of the images to prevent any external disturbance. A combination of multiple algorithms covers the whole tipping region of the cigarettes and checks for all targeted defects in the tipping. Image is divided into pixels and converted into Gray scale for faster processing. A Pixel and Hue counter algorithm is used to check for any deviation beyond allowable limits.
The image taken in each frame has four cigarettes visible, which gives good flexibility with respect to the processing times and possible configurations of the algorithms to be used. Multiple versions of algorithms have been developed to cater to specific machine types and brands of the cigarette being run on the machine. The system enables quick programming of any algorithms and storage of the programs in memory for use at any time. As a result of the running algorithms, a detection and rejection signal is generated which needs to be transferred to the making machine and synchronized with the maker machine rejection system so that the defected cigarette can be rejected exactly. Another, challenge at this stage is that, no false rejection or extra rejection should happen. Due to the high speeds of making machine (e.g. 3000 cigarettes per minute and above), the synchronization of both systems becomes a critical hurdle. A detailed and flexible interfacing system, as explained in Figure 3, has been developed to synchronize the Image Processing Computers and the Maker Machine so that the defective cigarette can be rejected without any issue on any maker type or speed.
As regards the synchronization process referred in figure 3, the sensor provides information regarding running speed of maker machine to the Cigarette Inspection Device unit, which is responsible for operating the rejection system and converting the speed information into an electronic signal like Single Cigarette Pulse (SCP). The SCP is transferred to the Interfacing Device and the Image Processing Computer in order to keep all components of the system running in synchronization. The image capturing device such as CCD camera captures the images which are processed by the Image Processing Computer. If a defective cigarette is found based on the developed algorithm, a rejection signal is sent to the Interfacing Device by the Image Processor. The Interfacing Device keeps track of all SCP signals and rejection signals and makes the synchronization possible using the developed method. Based on the machine speed and the rotational distance between the inspection station and the rejection station, a Synchronized Reject Signal is generated by the Interfacing Device which when sent to the Cigarette Inspection Device leads to the rejection of the defective cigarette only.
The advantages of the present system are numerous.
The developed logic of image processing is fast enough to provide 100% inspection of cigarettes in a quantitative and uniform fashion.
Also, the system is flexible enough to inspect a wide variety of cigarette parts at high production rates by merely having an operator teach the system certain operating parameters of the system. Finally, the system is capable of providing information that can be used to correct or improve the production process of the parts and is compatible with other "factory of the future" technologies.
This system has been provided with a LCD Display and Memory Storage Device, where all interactions with the system for configuration and data display can be done. Running images are shown on the LCD display for the reference of the operator in order to provide working reference.