Abstract:
Contemplated fully automated coffee roaster have significantly reduced energy demands, use electrical heat as a heat source in a temperature-only driven program mode, and eliminate smoke and smell within the roaster. Most preferably, contemplated fully automated roasters will consume only about 10 percent of the energy as compared to known devices on a per kilogram basis of beans and require no operator experience.

Description:
This application claims priority to the Korean national patent application with the serial number 10-2006-0099924, which was filed Oct. 13, 2006. 
     FIELD OF THE INVENTION 
     This invention relates to a coffee roaster and controlling methods of same, particularly, to a coffee roaster for economizing in electric power only by using electrical heat as a heat source when roasting coffee beans, eliminating smoke by burning the smoke generated when roasting coffee beans within the device itself and eliminating smell generated when roasting coffee beans, and a method of controlling the same, in which an optimal method for roasting coffee beans is selected in advance and then preset in a micro-computer of a control unit so that inexperienced users can easily roast coffee beans to an optimum state. 
     BACKGROUND OF THE INVENTION 
     In general, when using electric power as a heat source for roasting coffee beans, the heat source for roasting 1 kg of coffee beans needs 14 to 20 KW. Thus, if the weight of coffee beans to be roasted is 1 kg or more, gas heating (for example, propane gas and LNG gas) is almost always used. However, gas heating typically requires an expert to predictably roast coffee beans to an predetermined degree. 
     Further, an important know-how for roasting coffee beans is to find certain points when a first crack sound is generated upon applying the heat to green beans, wherein the first crack sound is failed by reducing the heat after a while, and when the heat is further reduced after a second crack sound is generated again so that the beans have a desired color. 
     As described above, since the technique of roasting coffee beans is largely depended upon the expert&#39;s experience and skill to find the points of the first, second, and third crack sounds and requires increasing or reducing the heat while observing and heating the roasted coffee beans, it generally very difficult, if not even impossible for an inexperienced user to predictably and reliably roast coffee beans to a desired state. Even though new machines for roasting coffee beans using hot air have been developed, resulting roasted coffee is often not satisfactory for the general public. Thus, the coffee roasting industry largely relies on expert roasters. 
     Further, when roasting the coffee beans, a considerable amount of smoke is generated, which is in heretofore known devices typically discharged to the outside by installing a smoke pipe, or eliminated by installing a large smoke collector (often 5 to 6 times larger as the roasting machine) above the device in combination with an after-burner for burning the smoke collected in a smoke reserve tank (which is also six or more times as large as the roasting machine). Therefore, a very large space is required to roast coffee beans using heretofore known devices. Moreover, a smoke pipe is often essential to discharge the burned gas placing further restriction to general use. Consequently, coffee bean roasting is generally performed only in factories or smaller roasting operations, even when roasting a small amount (several kilogram) of coffee beans. 
     Therefore, there is still a need to provide improved coffee roasting devices that will allow fully automated operation by an inexperienced user or even novice at significantly reduced power consumption. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide a coffee roaster which can efficiently roast coffee beans by using an electrical heater with very small power consumption and eliminate smoke and smell generated when roasting coffee beans, whereby everyone can easily roast coffee beans in the optimum state while maintaining comfortable circumstances in a room. 
     It is another object of the present invention to provide a coffee roaster which is provided with an equipment for removing the smell and cooling the green beans instead of a separate large-sized equipment so as to be installed at any places and circumstances, and which is provided as a power saving automatic machine like home electronics so that everyone can easily use it. 
     It is yet another object of the present invention to provide a coffee roaster which is made smaller for saving electricity, in which an electric heater is appropriately disposed so as to be capable of removing the smoke and providing the additional heating, and in which an open air coil heater, a ceramic heater and sheath heater are disposed at the outside of a rotating drum, and in which a halogen lamp heater for directly transferring heat to the beans is installed within the drum to increase thermal efficiency. 
     It is yet another object of the present invention to provide a coffee roaster in which a curved reflector is installed at the upper side of the halogen lamp heater to protect the halogen lamp heater and to reflect light downwardly. 
     It is yet another object of the present invention to provide a coffee roaster provided with a multi-step smoke eliminator assembly in which a coil heater is wound up in a spiral shape within a ceramic base through which smoke generated in the rotating drum is smoothly guided and then completely burned at high temperature (about 700˜1000° C.) while passing along the heat coil. 
     It is yet another object of the present invention to provide a coffee roaster in which water is injected into the rotating drum so that steam is generated by the heat of the rotating drum and the roasted beans, and the smoke is pushed out by the steam and then completely removed by a smoke eliminator and a deodorizer (typically activated charcoal filter). 
     In order to accomplish these and other objects, a coffee roaster according to the present invention comprises a casing of a coffee roaster assembly; a rotating drum which is installed in the casing to roast beans; a drum shield for surrounding an outer surface of the rotating drum; heating elements, including a halogen lamp heater which is installed in the rotating drum to heat the rotating drum and beans, an open air coil heater assembly which is installed at an upper part of the drum shield and a ceramic heater and a sheath heater which are respectively installed at the sides of the drum shield; a first sensor for bean temperature which is disposed at an inside of the rotating drum to measure a temperature of the beans; a second sensor for drum temperature which measures an inner temperature of the rotating drum; a memory element for storing data values of temperatures of the beans and the rotating drum, which are measured by the first sensor for bean temperature and the second sensor for drum temperature in a desired time after points of first and second cracks; and a control unit for automatically adjusting the roasting of beans by reducing the inner temperature of the rotating drum by controlling the heating means when the temperatures of the beans and the rotating drum arrive at the data values. 
     According to the present invention, a method of controlling a coffee roaster comprises a first step of previously storing data values of an inner temperature of a rotating drum and a temperature of beans, which are measured in a desired time after first and second cracks are occurred, in a memory; a second step of determining whether the inner temperature of the rotating drum and the temperature of beans arrive at the stored data values; and a third step of controlling heating means to reduce the inner temperature of the rotating drum if the inner temperature of the rotating drum and the temperature of beans arrive at the stored data values. In especially preferred aspects, the control operation is exclusively achieved by adjusting the temperature settings (and not by including time as a determinant in the roasting process). 
     Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a front perspective view showing an exemplary coffee roaster assembly and an exemplary cooling table assembly according to the present invention; 
         FIG. 2  is a rear perspective view of  FIG. 1 ; 
         FIG. 3  is an exploded perspective view showing a cooler and a smell eliminator of the cooling table assembly according to the present invention; 
         FIG. 4  is an exploded perspective view showing assembly of an exemplary coffee roaster according to the present invention; 
         FIG. 5  is a front right exploded perspective view showing the inside of an exemplary coffee roaster according to the present invention; 
         FIGS. 6A and 6B  are an exploded perspective view showing an installed smoke eliminator assembly and a rear left perspective view showing the inside of the smoke eliminator assembly, respectively. 
         FIG. 7  is an exploded perspective view showing the smoke eliminator assembly of the coffee roaster according to the present invention; 
         FIG. 8  is an exploded perspective view showing an upper side of an open air coil heater of the coffee roaster according to the present invention; 
         FIG. 9  is an exploded perspective view showing a halogen lamp heater of the coffee roaster according to the present invention; 
         FIG. 10  is an exploded perspective view showing a water tank assembly of the coffee roaster according to the present invention; 
         FIG. 11  is an exploded perspective view showing a roasted bean outlet of the coffee roaster according to the present invention; 
         FIG. 12  is an exploded perspective view showing a cooling unit of the cooling table assembly according to the present invention; 
         FIG. 13  is an exploded perspective view and a partially enlarged perspective view showing a cooled bean outlet door opener shown in  FIG. 12 ; 
         FIG. 14  is a view showing an example of a main image displayed on a touch screen monitor of the coffee roaster according to the present invention; 
         FIG. 15  is a flow chart showing an exemplary roasting process in a scanner mode according to the present invention; 
         FIG. 16  is a flow chart showing an exemplary roasting process in an auto mode according to the present invention; 
         FIG. 17  is a flow chart showing an exemplary roasting process in a manual mode according to the present invention; 
         FIG. 18  is a flow chart showing an exemplary roasting control process in the coffee roaster according to the present invention; and 
         FIG. 19  is a graph showing temperature and time for each roasting stage in an exemplary roasting control process according to the present invention. 
         FIG. 20  is an exemplary diagram of components for control of operation of contemplated automated roasters. 
     
    
    
     DETAILED DESCRIPTION 
     In a preferred embodiment of the present invention, there is disclosed a rotating drum type coffee roaster using electric heat for roasting 5 kg of green beans. Also, “green beans” means beans before being completely roasted in a rotating drum, and “coffee beans” means beans that are completely roasted in the rotating drum. 
     In a coffee roaster according to the present invention, an electric heater which can simply and precisely control the temperature is used as a heat source so that everyone can easily roast coffee beans, electricity consumption is reduced, and heat efficiency is enhanced by employing an array of the electric heaters and heat distribution devices/schemes. Further, the size of the rotating drum is decreased relative to known roaster drums for equivalent amounts of green beans to further reduce power consumption as well as to increase heat efficiency. 
     In heretofore known devices, a conventional coffee roaster is provided with a large fin in the rotating drum. In contrast, contemplated devices include a thin spiral strip on an inner surface of rotating drum to evenly mix the coffee beans by operating the rotating drum in a clockwise or counter-clockwise direction, thereby reducing the size of the rotating drum and thus maximizing the power saving. 
     Further, according to the present invention, the open air coil heater assembly is disposed at an upper side of the rotating drum so that, when smoke generated from the coffee beans in the roasting process rises upwardly, the open air coil heater assembly heats and burns the collected smoke and thus the smoke is more easily burned in a second step smoke eliminator. Further, the outer surface of the rotating drum is heated to support the roasting process. 
     Additionally, one or more ceramic heaters are disposed on the surfaces of the upper end of the rotating drum to heat an upper side of the rotating drum so that oil runs out of the coffee beans, thereby improving a taste for coffee. A halogen lamp heater is positioned (on a preferably central upper part) within the rotating drum to directly heat the coffee beans. The above array of the heaters are made in view of maximizing power saving. 
     The present invention includes a built-in type compact smoke eliminator  40 . As shown in  FIGS. 7 and 1 , first and second step smoke eliminator assemblies  41  and  42  of the smoke eliminator  40  includes ceramic bases  41 - 2  and  42 - 2  which are piled up in multiple stages, spiral coil heaters  41 - 1  and  42 - 1  which are respectively wound up in a spiral shape within the ceramic bases  41 - 2  and  42 - 2 , and ceramic heater cases  41 - 3  and  42 - 3  in which the assembly of the ceramic bases  41 - 2  and  42 - 2  and spiral coil heaters  41 - 1  and  42 - 1  is installed. 
     By the spiral type installation of the spiral coil heaters  41 - 1  and  42 - 1  in the ceramic bases  41 - 2  and  42 - 2 , the smoke is flown smoothly and also heated continuously while being risen up along the ceramic bases  41 - 2  and  42 - 2 , thereby improving the smoke eliminating function. A plurality of upholding bosses  41 - 3  are formed at the ceramic bases  41 - 2  and  42 - 2 , in which the spiral coil heaters  41 - 1  and  42 - 1  are installed, to prevent a short-circuit between the spiral coil heaters  41 - 1  and  42 - 1 . Further, since the smoke generated when roasting the coffee beans is completely burned by the first and second step smoke eliminator assembly  41  and  42 , a separate smoke pipe is not needed. 
     Further, in order to remove smell generated at an early stage of the roasting, the present invention employs an activated carbon which functions to remove a bad smell. 
       FIG. 1  is a front perspective view showing a respective constitution of a coffee roaster assembly and a cooling table assembly according to the present invention,  FIG. 2  is a rear perspective view of  FIG. 1 ,  FIG. 3  is an exploded perspective view showing a cooler and a smell eliminator of the cooling table assembly according to the present invention,  FIG. 4  is an exploded perspective view showing a constitution of the coffee roaster assembly according to the present invention,  FIG. 5  is a front right exploded perspective view showing the inside of the coffee roaster assembly according to the present invention,  FIGS. 6   a  and  6   b  are an exploded perspective view showing the smoke eliminator assembly and a rear left perspective view showing the inside of the smoke eliminator assembly according to the present invention,  FIG. 7  is an exploded perspective view showing the smoke eliminator assembly of the coffee roaster according to the present invention,  FIG. 8  is an exploded perspective view showing an upper side of an open air coil heater of the coffee roaster according to the present invention,  FIG. 9  is an exploded perspective view showing a halogen lamp heater of the coffee roaster according to the present invention,  FIG. 10  is an exploded perspective view showing a water tank assembly of the coffee roaster according to the present invention,  FIG. 11  is an exploded perspective view showing a roasted bean outlet of the coffee roaster according to the present invention,  FIG. 12  is an exploded perspective view showing a cooling unit of the cooling table assembly according to the present invention and  FIG. 13  is an exploded perspective view and a partially enlarged perspective view showing a cooled bean outlet door opener shown in  FIG. 12 . 
     As shown in drawings, a coffee roaster assembly  1  includes a casing  1 - 1  which forms external appearance, a rotating drum  10  which is installed in the casing  1 - 1  to roast green beans, a hopper assembly  50  provided at an upper part of a front side of the casing  1 - 1  to input green beans, a bean chute  51  which is disposed at a lower part of the hopper assembly  50 , and a bean shutter  52  which is provided as a gate in a path of the bean chute  51 . 
     The bean shutter  52  is controlled by a control unit  100  to be opened when a temperature within the rotating drum  10  arrives at a predetermined preheating temperature, when a bar code scanner  106  reads a bar code printed on a green bean packing material, or when a wireless reader (not shown) reads information of electronic tag. 
     The bar code scanner  106  is connected to a USB port or an RS232 installed in the control unit  100  to input bar code information printed on a green bean packing material. Alternatively, an electronic tag having a microchip for storing cooking information and provided at the green bean packing material, and a non-contact wireless reader for reading the cooking information from the electronic tag may be installed in the control unit  100 . 
     The bean shutter  52  is opened and closed by a bean shutter geared motor  53  which can rotate in both clockwise and counter-clockwise directions. 
     For example, in a scan mode, when scanning the bar code of the green bean packing material with the bar code scanner  106  or when positioning the electronic tag at a frequency region generated from the wireless reader, green bean information (bean data) recoded on the bar code or the electronic tag is input to a microcomputer of the control unit  100 , and then preheating is started by a user&#39;s operation for starting the roasting. At this time, when arriving at a predetermined preheating temperature, the microcomputer of the control unit  100  displays a message for informing completion of the preheating on a screen and then controls the bean shutter to be opened so that the green beans to be roasted can be entered into the rotating drum  10 . 
     In an auto mode, when selecting a preset roasting profile, a message for entering the green beans is displayed. However, the bean shutter  52  is not opened for incorrect information or used information which was read formerly, that is the bean shutter  52  is opened only when the bar code or the electronic tag is read by the bar code scanner or the wireless reader and also a preheating temperature arrives at a predetermined value. 
     The rotating drum  10  is rotated by a rotating force from a drive motor  21  fixed on a rear supporting plate  12  by a bracket  23 . At this time, the rotating force of the drive motor  21  is transmitted through a pulley  27  and a timing belt  26  to the rotating drum  10 . 
     The rotating drum  10  is in the form of a cylinder, and numerous holes are formed in an outer surface of the rotating drum  10 . The control unit  100  sends an operating signal to the drive motor  21  at sufficient intervals of time that inertial force of drive motor is vanished away so that the drive motor can be repeatedly operated in the clockwise and counter-clockwise directions while prevented from being overheated. By the rotation of the rotating drum  10 , the green beans can be evenly heated. 
     In order for the rotating drum  10  to rotate smoothly, heat-resisting bearings  24 A and  24 B are respectively installed at both ends of the rotating drum  10 . 
     The bearings  24 A and  24 B are attached to front and rear supporting plates  11  and  12 . To prevent a leakage of smoke and hot air from the rotating drum  10 , seals  25 A and  25 B are inserted within the bearings  24 A and  24 B. Preferably, the bearings  24 A and  24 B are made of a heat-resisting material. 
     To apply heat to the green beans within the rotating drum  10 , an open air coil heater assembly  32  is installed on an upper end of a drum shield  13  for surrounding the rotating drum  10 , and a ceramic heater  33  and a sheath heater  34  are installed on both right and left inclined surfaces of the upper end of the drum shield  13 . 
     As shown in  FIG. 8 , the open air coil heater assembly  32  includes a heater base  32 - 3  fixed to the upper end of the drum shield  13 , a plurality of lower insulated ceramic bars  32 - 1 B which are disposed in parallel on the heater base  32 - 3 , a plurality of upper insulated ceramic bars  32 - 1 A which are disposed to be opposite to the lower insulated ceramic bars  323 - 1 B, and an open air coil heater  32 - 2  which are installed in grooves formed between the lower insulated ceramic bars  32 - 1 B and upper insulated ceramic bars  32 - 1 A. The lower insulated ceramic bars  32 - 1 B and upper insulated ceramic bars  32 - 1 A are fastened to the heater base  32 - 3  through bolts  32 - 4  and nuts  32 - 5 . 
     And, a halogen lamp assembly  31  is provided at a front part  11  to be positioned on a central upper part within the rotating drum  10 . By directly heating the green beans with the halogen lamp heater  31 , roasting efficiency is maximized. 
     As shown in  FIG. 9 , the halogen lamp assembly  31  has a reflector  31 - 1  for covering an upper side of an U-shaped halogen lamp heater  31 - 2  made of a glass tube to transfer heat and radiant light to the beans positioned in a lower part within the rotating drum  10 . The reflector  31 - 1  also serves to protect the glass tube from the beans dropped within the rotating drum  10  and to prevent a heat loss at the upper part of halogen lamp heater  31 - 2  by reflecting light generated from the halogen lamp heater  31 - 2  downwardly. 
     In the embodiment of the coffee roaster according to the present invention, there are provided four heaters. The halogen lamp assembly  31  provides the heat of the permeable light to the inside of the rotating drum  10  so that the beans are roasted uniformly, and the open air coil heater  32 - 2  firstly heats and burns the smoke. Further, the open air coil heater  32 - 2  serves to heat air at the upper part of the rotating drum  10  and thus to increase the inner temperature of the rotating drum  10 . 
     The sheath heater  34  is installed on the left inclined surface of the upper end of the rotating drum  10  to heat the rotating drum  10 . Therefore, when the beans enter into the rotating drum  10 , the heat is indirectly transferred to surfaces of the beans so that oil runs out of the coffee beans, thereby improving a taste for coffee. 
     Furthermore, the ceramic heater  33  is installed on the right inclined surface of the upper end of the rotating drum  10  to prevent a rapid decrease in the inner temperature of the rotating drum  10  when supplying voltage is changed. 
     If the beans within the rotating drum  10  are heated, the beans are expanded and then shells thereof are peeled and the smoke is generated. 
     The peeled shells are dropped through numerous holes having a diameter of about 4 to 5 mm formed in a hole plate  10 - 1  of the rotating drum  10  and then are piled up in a shell drawer  16 . The shell drawer  16  is disposed at a lower side of the rotating drum  10  to be separated in a sliding manner. 
     At this time, the smoke is rising up through the holes of the hole plate  10 - 1  of the rotating drum  10 . Then, the smoke is firstly burned and heated by the lower open air coil heater assembly  32  which is mounted in an opening  13 - 1  formed at an upper surface of the drum shield  13 . Then, the smoke enters into a smoker eliminator  40  via holes  13 - 3  of the drum shield  13 . 
     As shown in  FIGS. 4 and 7 , the smoke eliminator  40  includes a first step smoke eliminator assembly  41 , a second step smoke eliminator assembly  42  and a vapor shutter  45 . The smoke is completely burned while passing through the two heater assemblies. 
     The first step smoke eliminator assembly  41  and the second step smoke eliminator assembly  42  are installed in a smoke eliminator case  43 , and the vapor shutter  45  is disposed at an vapor exhaust  44 - 1  which is formed at a smoke eliminator cover  44  for covering the first step smoke eliminator assembly  41  and the second step smoke eliminator assembly  42 . 
     Meanwhile, when roasting the green beans, moisture (generally, 12 to 15% of the weight of the green beans) generated from the green beans is vaporized and then generates steam. The rotating drum  10  is filled with the generated steam and then the pressure within the drum  10  is increased. Thus, it is required to properly discharge the steam from the rotating drum  10 . To this end, there is provided an exhaust vent fan  85  which is installed in a lower exhaust hole  83  formed at a lower side of a deodorizer  80 . 
     At this time, if the exhaust vent fan  85  is operated at an early stage of the roasting, the roasting is not performed satisfactorily by a large heat loss. However, if the exhaust vent fan  85  is not operated, the steam is accumulated in the rotating drum  10  and then discharged through an exhaust hole of deodorization  2 - 6  when the exhaust vent fan  85  is operated, and thus the steam may be mistaken for the smoke. 
     As shown in  FIG. 7 , the steam is partially removed by the heat while passing through the first step smoke eliminator assembly  41 . Meanwhile, a control solenoid  45 - 1  is installed at the vapor shutter  45  to be controlled by the microcomputer of the control unit  100 . The control solenoid  45 - 1  controls the vapor shutter  45  to discharge and shut the steam. 
     Meanwhile, a lower end of the second step smoke eliminator assembly  42  of the smoke eliminator  40  is connected through a connection pipe  46  to an upper suction hole  82  which is installed on an upper side of the deodorizer  80 . 
     A heat isolation wall  47  is installed at a circumference of the connection pipe  46  to prevent a trouble due to the hot air radiated from the smoke eliminator  40 . 
     As described above, the generated smoke is almost burned out by the smoke eliminator  40  and the deodorizer  80 . However, the smoke among the beans also has to be removed. 
     Therefore, water is sprayed to the coffee beans so that the smoke among the beans rises upwardly. Then, the risen smoke is completely burned while passing through the smoke eliminator  40  and the deodorizer  80 . 
     The construction for spraying water, as shown in  FIGS. 4 and 10 , includes a water tank assembly  76  for storing water, a water pump assembly  76 - 2  for forcibly moving the water stored in the water tank assembly  76  and a spray nozzle  76 - 1  for spraying the water to the beans within the rotating drum  10 . 
     Moreover, in order to automatically supply water to the water tank assembly  76 , a separate water valve (not shown), a solenoid value assembly  76 - 3  and a floating switch  76 - 5  may be selectively provided. 
     If there is the tap water in the neighborhood of the coffee roaster assembly  1 , a water supplying pipe is connected to the water valve (not shown) provided at a rear side of the coffee roaster assembly  1 . In this state, if signal power is applied to the solenoid valve  76 - 3  for spraying water, the solenoid valve  76 - 3  is opened and thus water is supplied to the water tank assembly  76 . And if water is filled to an upper part of the water tank assembly  76 , the floating switch is turned off and the solenoid valve  76 - 3  is closed. 
     If there is not the tap water in the neighborhood of the coffee roaster assembly  1 , water may be manually supplied to the water tank assembly  76 , for example, by using a kettle. The amount of water is automatically set by a program of the control unit  100 . The spraying of water prevents a damage of the activated carbon and increase deodorizing efficiency. This control process is operated by the microcomputer. 
     When roasting coffee beans, unpleasant smell is generated. To remove the smell, the deodorizer  80  is installed in the cooling table assembly  2 . The deodorizer  80  includes activated carbon cartridges  84 A,  84 B and  84 C. Right and left doors  2 - 1  and  2 - 2  are provided at a front surface of the cooling table assembly  2  to open and close the front surface thereof. The deodorizer  80  is sealed from the outside so that the outside air is not flown therein and further includes a front door  80 - 2  and a plurality of guide rails  80 - 1  for supporting and guiding the activated carbon cartridges  84 A,  84 B and  84 C. The cartridges are filled with activated carbons. The cartridges are arrayed at intervals of 30 to 40 mm. These intervals serve to prevent the activated carbon from the damages due to the heated smoke for roasting the coffee beans and removing the smoke, and heat accumulated in the activated carbon, 
     The smell is removed by the deodorizer  80  in the following manner. If an exhaust vent fan  85  installed in a lower part of the deodorizer  80  is driven according to absorption amount and time which are preset by the control unit  100 , the remaining smoke and smell is absorbed and removed by the activated carbon while passing through the activated carbon cartridges  84 A,  84 B and  84 C. The activated carbon cartridges  84 A,  84 B and  84 C have an upper frame and a lower frame which are covered with wire netting to contain the activated carbon. The smoke or gas passes through the wire netting. 
     After passing through the activated carbon cartridges  84 A,  84 B and  84 C, contaminated air changes is turned into fresh air and then the fresh air is discharged through an outlet of the exhaust vent fan  85  and the exhaust hole of deodorization  2 - 6  formed in a lower part of the cooling table assembly  2 . Thus, according to the coffee roaster of the present invention, the air contamination in a room is prevented, whereby the coffee roaster is possible to be installed in any places in the room. 
     The activated carbons in the activated carbon cartridges  84 A,  84 B and  84 C are made of coal material. Preferably, the activated carbons have a particle size of 5˜10 mm, a packing density of 0.45˜0.56 g/ml, a hardness of 90 mm and an iodine adsorption number of 900˜100 min. 
     The smoke removed in the smoke eliminator  40  has very high remaining heat (about 200˜250° C.). Therefore, there is the necessity of preventing the damage of the activated carbons due to this high remaining heat. As a first solution of the problem, the control unit  100  controls the deodorizer  80  to remove a proper amount of the steam generated from the moisture of 12 to 15% contained in the green beans, thereby reducing the amount of steam to be burned. As a second solution of the problem, in order to prevent the heat from being accumulated in the activated carbon, a part of the steam generated when roasting beans is completely removed while passing the first step smoke eliminator assembly, and only the gas is discharged to the vapor shutter  45 . Other part of the steam is sent to the deodorizer  80  and then removed by the activated carbon. Thus, the damage of the activated carbon is prevented while the remaining smoke and smell are removed. 
     Meanwhile, in order to correctly roast the beans in the optical state, there are provided a first sensor  78 - 1  for bean temperature which is disposed at a lower part of the rear supporting plate  12  to measure the temperature of the beans and a second sensor  78  for drum temperature which is disposed at a lower part of the bean chute  51  to measure the temperature of air within the rotating drum  10 . According to the present invention, when a crack sound is generated upon applying the heat to green beans, anyone can simply set program according to the measured temperature of the first sensor  78 - 1  for bean temperature and thus easily roast coffee beans in the optimal state. 
     If the beans are roasted to have a desired color, the control unit  100  controls a geared motor  65  for roasted bean outlet door to rotate a gear  63  for roasted bean outlet coupled with a rotational shaft  66  of a roasted bean outlet  61 , so that the roasted bean outlet  61  is opened. Simultaneously, the rotating drum  10  is rotated in a direction for sliding down the beans. Then, the beans are slid down along a roasted bean chute skirt  64  and then are dropped in a cooling unit  90 . As shown in  FIG. 11 , after discharging the beans, the control unit  100  controls the geared motor  65  for roasted bean outlet door to be driven in a reverse direction so that the gear  63  for roasted bean outlet is also rotated in the reverse direction and thus the roasted bean outlet  61  is closed. The roasted bean outlet  61  installed at the roasted bean chute skirt  64  is provided with a visible door  62 . 
     Further, a rubber packing  68  is attached to a front casing  17  which is contacted with the roasted bean outlet  61 , and thus if the roasted bean outlet  61  is closed, an inner space therein is made airtight. The rubber packing  68  is provided with one or more permanent magnet  67 . Therefore, when opening the roasted bean outlet  61 , the roasted bean outlet  61  is opened only in case that a desired torque is applied, thereby preventing the roasted bean outlet  61  from being unintentionally opened, and when closing the roasted bean outlet  61 , the roasted bean outlet  61  is closed easily with a small force. 
     A hole panel  91  is disposed at an upper part of the cooling table assembly  2  to be positioned at a lower side of the roasted bean outlet  61  so that the beans roasted in the rotating drum  10  are dropped in a cooling unit  90 . A ventilation motor  96  is connected with an air suction connector  95 -A formed at a lower part of the hole panel  91 . Thus, the outside air is flown through the air suction connector  95 -A into the hole panel  91  and the fresh roasted beans are rapidly cooled by the outside air. 
     As shown in  FIG. 12 , the hole panel  91  is formed with an upper opening  91 - 1  for receiving the beans discharged through the roasted bean outlet  61 , and a bottom surface  91 - 2  having a plurality of holes through which the outside air sucked by the sirocco ventilation motor  96  is passed. Further, at a lower side of the hole panel  91 , there are provided an cooled bean outlet door  93  which controls the discharge of the cooled beans to the outside, and an cooled bean outlet chute  94  which is inclined downwardly to guide the cooled beans discharged from the cooled bean outlet door  93  to the outside. Further, a stirring rotator  92  is disposed at a center part of the hole panel  91  to stir the beans in a circumferential direction and thus to efficiently cool the beans. A cooled bean outlet door opener  95  is disposed at a lower side of the hole panel  91  to open and close the cooled bean outlet door  93 . 
     The stirring rotator  92  has a rod-shaped central shaft  92 - 1 . A lower end of the central shaft  92 - 1  of the stirring rotator  92  is rotatably fixed to the bottom surface of the hole panel  91 . At this time, the stirring rotator  92  is apart from the bottom surface of the hole panel  91  in a desired interval. Three branched parts  92 - 2  which are horizontally branched at angular intervals of 120 degrees are formed at an upper end of the central shaft  92 - 1 . Each of the branched parts  92 - 2  has a brush  92 - 3  for stirring the beans. Further, the lower end of the central shaft  92 - 1  of the stirring rotator  92  is coupled with a rotational shaft  92 - 5  connected with a stirring rotator driving motor  92 - 4 . 
     As shown in  FIG. 13 , the cooled bean outlet door opener  95  includes a rack gear  95 - 1  which is vertically disposed to guide the rotation of the cooled bean outlet door  93 , a pinion gear  95 - 2  which is rotatably engaged with the rack gear  95 - 1 , a reversible motor  95 - 3  for rotating the pinion gear  95 - 2  in forward and backward directions, and a cable  95 - 4  of which one end is connected with the cooled bean outlet door  93  and the other end is connected with an upper end of the pinion gear  95 - 2 . 
     If the reversible motor  95 - 3  is rotated in the forward direction, the rack gear  95 - 1  engaged with the pinion gear  95 - 2  is moved downwardly and thus the cooled bean outlet door  93  is rotated downwardly by the cable  95 - 4  of which both ends are respectively connected with the rack gear  95 - 1  and the cooled bean outlet door  93 , so that the cooled bean outlet door  93  is opened. On the other hand, if the reversible motor  95 - 3  is rotated in the backward direction, the rack gear  95 - 1  engaged with the pinion gear  95 - 2  is moved upwardly and the cooled bean outlet door  93  is rotated upwardly because tensile force of the cable  95 - 4  is eliminated, so that the cooled bean outlet door  93  is closed. 
     The reversible motor  95 - 3  is electrically connected with the control unit  100  and thus the cooled bean outlet door  93  is automatically opened or closed by the controlling of the control unit  100 . The discharged beans through the cooled bean outlet door  93  are collected in a proper container positioned at a lower side of the cooled bean outlet chute  94  and then the roasting process is finished. The cooled bean outlet chute  94  disposed between the cooled bean outlet door  93  and the cooled bean outlet door opener  95  is formed with a groove  94 - 1  through which the cable  95 - 4  is passed. 
     As shown in  FIG. 2 , a mesh-shaped filter  2 - 5  is disposed at one side of the cooling table assembly  2 . Therefore, it is prevented that the room is contaminated with the peels and scraps remained in the beans within the hole panel  91  when the ventilation motor  96  is operated. The filter  2 - 5  is detachably disposed at the cooling table assembly  2  to easily replace with new one. To this end, the filter  2 - 5  may be attached to the cooling table assembly  2  by various fastening means such as screws, bolts and so on. 
     Meanwhile, the control unit  100  includes a touch screen monitor  101  which is disposed at an upper part thereof and a driving part which is disposed at a lower side thereof to transfer signals from the microcomputer to each parts. An input part having a plurality of buttons is provided on the touch screen monitor  101  of the control unit  100  to adjust the roasting (referring to  FIG. 10 ). The input part is provided with a preheat button. By the operation of the preheat button, the temperature in the coffee roster reaches from an intermediate temperature to a normal roasting temperature within a short time. 
     The input part is further provided with an extinguishing button. When a fire breaks out in the beans during the roasting, particularly, upon interruption of electric power, the microcomputer of the control unit  100  senses the interruption of electric power and operates the water pump assembly with a charged battery to extinguish the fire. 
     And the input part is further provided with a cleaning button. The microcomputer of the control unit  100  informs a cleaning time through the monitor  101  and then automatically performs self-cleaning. When performing the self-cleaning, the steam is sprayed twice in the rotating drum  10  to keep the rotating drum  10  clean. In detail, during the self-cleaning, the temperature in the rotating drum  10  is automatically increased to 250˜270° C. to burn foreign materials and then to spray the steam in the rotating drum  10 , thereby automatically cleaning the inside of the rotating drum  10 . The control unit  100  of the coffee roaster may be managed in a status of connecting with a personal computer, and finally managed by a manufacturer through internet using a LAN cable which is connected to a LAN cable port provided in the control unit  100 . 
     Hereinafter, a using process of the coffee roaster according to the present invention will be described with reference to the drawings.  FIG. 14  is a view showing an example of a main screen displayed on a touch screen monitor of the coffee roaster according to the present invention,  FIG. 15  is a flow chart showing a roasting process in a scan mode according to the present invention,  FIG. 16  is a flow chart showing a roasting process in an auto mode according to the present invention,  FIG. 17  is a flow chart showing a roasting process in a manual mode according to the present invention,  FIG. 18  is a flow chart showing a roasting control process in the coffee roaster according to the present invention, and  FIG. 19  is a graph showing a temperature and a time for each roasting stage in the roasting control process according to the present invention. 
     Firstly, a basic operation like selecting of a roasting mode is performed. 
     1. SCAN MODE: A scan mode is to scan a bar code or to directly input the code and perform the roasting by using information recorded in the code. 
     2. AUTO MODE: In this mode, it is possible to perform the roasting by using preset roasting information without a separate setting operation, and it is classified into a presetting mode and a new setting mode. 
     1) PRESETTING MODE: selects the roasting information previously memorized in the auto mode and then performs the roasting. 
     2) NEW SETTING MODE: newly creates the information to be used in the presetting mode 
     3. MANUAL MODE: A user can freely select the roasting process. 
     4. MANAGEMENT: This menu is to provide various information and troubleshoot the coffee roaster by self-diagnostic or by connecting with a computer. It is classified into an online trouble shooting, a manual trouble shooting, a bean report, a daily report and a download mode. 
     1) ONLINE TROUBLESHOOTING: connects with a computer of a manufacturer through network and performs the self-diagnostic for the heater, the motor, the solenoid and other parts. 
     2) MANUAL TROUBLESHOOTING: checks directly the heater, the motor, the solenoid and other parts. 
     3) BEAN REPORT: shows a kind of bean used by the user, a number of roasting operations and a weight of the beans. 
     4) DAILY REPORT: displays information for the roasting operations by date. 
     5) DOWNLOAD MODE: connects with a computer of a manufacturer through network and upgrades a program to a new version. 
     5. TIME SET: It is possible to correct a time in a built-in watch. 
     6. PREHEAT: This mode is to be on standby at a standby preheat temperature without the roasting. At this time, the standby preheat temperature keeps 150□. 
     7. COOLING: The ventilation motor in the cooling table assembly is operated to cool the beans in the cooling table assembly. 
     8. BEAN OUT: This mode is to extract the beans from the cooling table assembly. 
     9. CONTENTS OF INFORMATION WINDOW: 
     1) VERSION: displays a version of the present program. 
     2) DATE: displays a delivery date of a product. 
     3) NATION: displays a nation in which the coffee roaster is used. 
     4) MONTH, DATE, YEAR: displays a month, a date and a year 
     5) TEMP 1 : displays a temperature of the first sensor for bean temperature. 
     6) TEMP 2 : displays a temperature of the second sensor for drum temperature. 
     The selecting, operating, setting and inputting of each menu can be performed through the touch screen monitor. 
     Hereinafter, a roasting method in each mode will be described. In the scan mode, if a bar code is scanned, an electronic tag near is placed near a wireless reader, or a code is directly input, the roasting is performed by using the information recorded in the code. That is, the roasting is performed using the bean information recording in the code (which is preferably physically associated with the green bean package). 
       FIG. 15  is a flow chart showing a roasting process in a scan mode according to the present invention. In the scan mode, firstly, the power and the bar code scanner  106  or the wireless reader is switched on. The scan mode is selected from a main menu image of the touch screen monitor. Then, a bar code on a green bean packing material is input by using the bar code scanner  106  or the wireless reader. Herein, the bar code may be directly input through a screen of the monitor by touching numeral images displayed after selecting the scan mode. When the inputting of the bean information using the bar code or electronic tag is finished, information of temperature, time and bean to be roasted is displayed on the screen and a preheating process is performed by the operation for starting the roasting. 
     When arriving at the predetermined preheating temperature, a message for informing the finish of the preheating and instructing to insert the beans is displayed on the screen, a buzzer is turned on and the bean shutter is opened to insert the beans. These operations are all controlled by the control unit  100 . 
     Then, after inserting the beans manually, the user touches a “next” button to start the roasting. If the roasting is finished according to the user&#39;s selecting conditions such as a temperature of the rotating drum, first and second crack temperatures, a desired color of the roasted beans and so on, the roasted beans are automatically delivered to the cooling table assembly. The beans in the cooling table assembly are cooled and then discharged to the outside. The auto mode is to perform the roasting by using predetermined roasting information without a separate setting operation. The auto mode is classified into a presetting mode for selecting the roasting information previously memorized in the auto mode and then performing the roasting, and a new setting mode for newly creating the information according to user&#39;s taste. 
       FIG. 16  is a flow chart showing a roasting process in an auto mode according to the present invention. Referring to  FIG. 16 , when the coffee roaster is delivered to a user at the first time, the contents of the presetting mode is set to basic values. Therefore, to memorize new contents set by the user, the user starts the new setting mode and then inputs and stores the new roasting information. To this end, the user touches, in turn, an “auto mode” button and a “new setting” button on the main image, and then sets a kind of bean, a weight, a desired color of green beans to be roasted, a desired color of the roasted beans, a temperature of the rotating drum, first and second crack temperatures (roasting temperature), a time, etc. Then, if the user starts the roasting, the preheating is firstly performed. The process after the preheating is the same as in the scan mode. 
     The manual mode allows the user to freely select the roasting process. In this mode, the user can freely control the heater to adjust the temperatures and also change a roasting time.  FIG. 17  is a flow chart showing a roasting process in a manual mode according to the present invention. Firstly, the user selects a “manual mode” button and inputs various roasting information such as bean information, a temperature, a time and the like, and then manually operates each heaters to perform the preheating. 
     Then, when arriving at the predetermined preheating temperature, a message for informing the finish of the preheating and instructing to insert the beans is displayed on the screen, and the buzzer is turned on. The user inserts the beans in the roaster and starts the roasting. After the roasting is finished, as shown in  FIG. 13 , the roasted beans is cooled and discharged. These processes are also the same as in the scan mode and the auto mode. 
     Hereinafter, a control process of the roasting will be described with reference to  FIGS. 18 and 19 . The control process of the roasting is commonly applied to each mode shown in  FIGS. 15 to 17 .  FIG. 19  is a graph showing a temperature and a time for each roasting stage in the roasting control process according to the present invention, wherein a lateral axis represents a green bean treating process and a longitudinal axis represents the temperatures of the green beans and the rotating drum. Firstly, after turning on a main switch of the input part, the roasting is started according to each mode shown in  FIGS. 15 to 17  (S 100 ). In the process before the roasting, when the user wants to preheat the roaster before customers come, the user touches a “standby preheat” button after the touch screen monitor is turned on. At this time, the inner temperature of the rotating drum is maintained at a standby preheat temperature of 150° C. Then, if the user starts the roasting after selecting a profile for a kind of bean and a weight of the beans according to the customer&#39;s demand, the regular preheating is performed (at 250° C.). 
     When arriving at the predetermined preheating temperature, a message for instructing to insert the beans is displayed on the screen. At this time, the bean shutter  52  of the bean chute  51  is opened so that the beans are inserted therein. When the user touches the “next” button, the bean shutter  51  is closed and then the roasting is started. After that, the user determines whether the first, second and third temperatures T 1 , T 2 , and T 3  that the beans will be arrived are input (S 201 ). If the temperatures T 1 , T 2 , and T 3  are input, the roasting is started by operating the heating means. However, if the temperatures T 1 , T 2 , and T 3  are not input, the roasting is controlled by the temperatures stored in a memory (S 202 ). 
     As the heating means, the halogen lamp heater  31 - 2 , the open air coil heater  32 , the ceramic heater  33  and sheath heater  34  are operated in turn, and thus the inner temperature of the rotating drum is increased. The beans which are continuously heated by the four heaters are expanded, and crack sound is generated. A point when the crack sound is generated for the first time is called a first crack. The first crack is changed according to a kind of bean and a charged or stored stated. A temperature of the beans in desired time (within one minute) after the first crack is occurred is called a first temperature T 1 . Herein, the desired time may be variably set according to the user&#39;s taste. 
     Further, even when the heating means are tuned off in turn after the first crack, the beans are continuously heated and the crack is also occurred. A point when the crack sound is generated for the second time is called a second crack, and a temperature of the beans in desired time (within one minute) after the second crack is occurred is called a second temperature T 2 . 
     And a third temperature T 3  means a temperature that the beans will arrive to perform a final selection in the roasting for starting a process of injecting water in the rotating drum. 
     Data values of the first, second and third temperatures T 1 , T 2  and T 3  are previously stored in the memory. The user may change the data values during the roasting according to a customer&#39;s taste. 
     Graphs for showing the inner temperature of the rotating drum and the temperature of the beans are displayed on the monitor. At this time, if the first and second temperatures (T 1  and T 2 ) are displayed, the third temperature T 3  as the final temperature for determining the final color of the beans will be displayed. 
     As described above, these data values of the temperatures may changed by the user, and also the changed data values may be stored as a new program file in the microcomputer of the control unit. 
     The microcomputer determines whether the data values are input through the input part or stored in the memory and then applies power to the heating means like the halogen lamp heater to heat the beans in the rotating drum to the first temperature (S 202 ). 
     If the first temperature T 1  of the beans heated by the heating means is detected by the first sensor for beam temperature and then transferred to the microcomputer (S 204 ), the microcomputer reduces a first temperature DT 1  of the rotating drum to stop the first crack (S 205 ). 
     A bitter taste of coffee is adjusted by a deviation of reduction in the first temperature DT 1  of the rotating drum. That is, if the deviation of reduction in the first temperature DT 1  is large, the bitter taste is decreased. To reduce the first temperature DT 1  of the rotating drum, other heaters except the ceramic heater  33  is turned off in reverse order and, at the same time, the heat and smoke in the rotating drum is drawn out to the outside by controlling an operation time of the exhaust vent fan  85 . The deviation of reduction in the first temperature DT 1  of the rotating drum is previously stored in the memory to be capable of roasting the beans in the same state. Further, the deviation of reduction in the first temperature DT 1  of the rotating drum can be changed or reset during the roasting by the user. Herein, the first temperature DT 1  of the rotating drum means the inner temperature of the rotating drum when the beans arrive at the first temperature T 1 . 
     Moreover, according to the present invention, in order to efficiently operate the exhaust vent fan  85 , the bean shutter  52  of the hopper assembly  50  is opened so that the heat and smoke can be rapidly drawn out by inflow of outer air through the bean shutter  52 . 
     In the step of S 204 , though the inner temperature of the rotating drum is reduced, the beans are continuously heated by the ceramic heater  33  and thus the second crack is occurred. The second temperature T 2  of the beans is also transferred to the microcomputer by the first sensor for bean temperature (S 206 ). 
     Like in the step of S 205 , the microcomputer reduces a first temperature DT 1  of the rotating drum to stop the second crack (S 207 ). At this time, a deviation of reduction in the second temperature DT 2  of the rotating drum determines the bean&#39;s taste. That is, if the deviation of reduction in the second temperature DT 2  of the rotating drum is low, the heating temperature applied in the latter half of the roasting determines the oil amount run out of the beans. Also, the deviation of reduction in the second temperature DT 2  of the rotating drum is previously stored in the memory to be capable of roasting the beans in the same state. Further, the deviation of reduction in the second temperature DT 2  of the rotating drum can be changed or reset during the roasting by the user. Herein, the second temperature DT 2  of the rotating drum means the inner temperature of the rotating drum when the beans arrive at the second temperature T 2 . 
     When the first and second cracks are occurred, the roasting is basically completed. Then, to determine the taste of coffee, a process of making the color of beans dark is performed. That is, the roasting color comprises a light color, a medium color and a dark color and a pitch color, and each color is also divided into five grades according to the temperature of the roasted beans. Therefore, the roasting color can be always adjusted uniformly. 
     In the step of S 207 , it is determines whether the beans arrive at the final third temperature T 3  while the inner temperature of the rotating drum is continuously reduced (S 208 ). If the beans do not arrive at the third temperature T 3 , the beans will be heated continuously. However, if the beans arrive at the third temperature T 3 , water is injected into the rotating drum (S 209 ). Preferably, the third temperature T 3  is the temperature of the beans in the desired time after the third crack sound is generated, and the desired temperature DT 3  means the inner temperature of the rotating drum when the beans arrive at the final temperature T 3 . 
     If the beans arrive at the final roasting temperature T 3 , water corresponding to 5% of the weight of the beans is injected in third or fourth times to the beans so that the temperature of the beans does not increased, and then the roasting is finished. 
     When the water is injected in third or fourth times, the steam is generated and thus the smoke among the beans is pushed out by the steam and then delivered to the deodorizer. Therefore, when the beans are delivered to the cooling unit  90 , the smoke is not discharged to the room. That is, part of the smoke is completely burned by the heater disposed at the drum shield and the spiral coil heaters of the first and second heater assemblies, and the rest of the smoke is delivered to the deodorizer and completely eliminated. 
     By the water injected to the beans, the aroma of coffee is richer and the smoke and smell is removed, and a problem in packing the beans due to the expansion of the beans is also solved. The cooling operation in the cooling unit  90  is performed by cool air generated by the sirocco ventilation motor. After placing a container for receiving the roasted beans under the cooling unit  90 , the user touches a “bean-out” button displayed on the monitor. Then the cooled bean outlet door opener  95  is opened and the beans are discharged therethrough while stirred by the stirring rotator  92 . After the discharge of the beans is completed, the cooled beans outlet chute  94  is automatically closed and the roasting is finished. 
     According to the coffee roaster of the present invention as described above, the coffee beans can be efficiently roasted by using an electrical heater with very small power consumption and smoke and smell generated when roasting coffee beans is removed, whereby everyone can easily roast coffee beans in the optimum state while maintaining comfortable circumstances in a room. Further, the coffee roaster of the present invention is provided with an equipment for removing the smell and cooling the green beans instead of a separate large-sized equipment so as to be installed at any places and circumstances, and which is provided as a power saving automatic machine like home electronics so that everyone can easily use it. 
     Further, a coffee roaster of the present invention is made smaller for saving electricity, and in which an electric heater is appropriately disposed so as to be capable of removing the smoke and providing the additional heating, and an open air coil heater, a ceramic heater and sheath heater are disposed at the outside of a rotating drum, and a halogen lamp heater for directly transferring heat to the beans is installed within the drum to increase thermal efficiency. 
     Further, in the coffee roaster of the present invention, a bent reflector is installed at the upper side of the halogen lamp heater to protect the halogen lamp heater and to reflect light downwardly. 
     Further, the coffee roaster of the present invention is provided with a multi-step smoke eliminator assembly in which a coil heater is wound up in a spiral shape within a ceramic base so that the smoke generated in the rotating drum is smoothly flown and then completely burned by the temperature (about 700˜1000° C.) of the heat coil while passing along the heat coil. 
     Further, in the coffee roaster of the present invention, water is injected into the rotating drum so that steam is generated by the heat of the rotating drum and the roasted beans, and the smoke is pushed out by the steam and then completely removed by a smoke eliminator and a deodorizer. 
     Thus, specific embodiments and applications of coffee roasters and methods for control of same have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.