Abstract:
A safety system for an ice and liquid dispenser of a refrigerator is used to sense the presence of human skin in a dispensing well. The safety system includes a digital image capture device focused on a dispenser well for capturing images of objects, such as hands, in the dispenser well and a digital image analyzer operatively coupled to the digital image capture device. The digital image analyzer evaluates the digital images captured by the digital image capture device to determine if human skin color is detected in the image of the object in the dispensing well. If human skin color is detected, thus indicating a hand in the dispensing area, any dispensing operation will be prevented and an alert will be provided.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention pertains to the art of refrigerators and, more particularly, to incorporating an imaging system for a refrigerator ice and liquid dispenser. 
         [0003]    2. Description of the Related Art 
         [0004]    Modern refrigeration mechanisms, such as refrigerator/freezer units, have electrically powered actuators that perform a variety of functions. An example is an ice maker/dispenser. Normally, electrical motors perform functions such as operating valves to supply water to the ice maker, moving a rod or rack to eject ice that has been frozen from supplied water, and moving other structure to convey, alter or direct ice pieces to an ice delivery or dispensing chute. 
         [0005]    In the case of an ice maker/dispenser, a user normally must manually push a button with a finger or move a glass or container against a lever to actuate a motor to dispense ice down the chute. In some models, the user can also manually push a button to select between ice cubes or crushed ice and, in some instances, shaved ice. Normally, once actuated, the dispenser operates until the user releases the button or lever. In some cases, the dispenser motor continues until automatically stopped by a timer. 
         [0006]    In either of these cases, there are situations where it may be desirable to activate a warning signal or provide some form of notification when an unusual activity occurs during a dispensing operation. For example, if a child reaches into the ice dispensing area or the ice dispensing chute, it may be appropriate to provide a signal to the child or a nearby adult. To this end, it would be advantageous to automatically detect the presence of a human hand and activate a warning signal until the situation can be resolved. This would be particularly advantageous in refrigerators that have an ice crushing system located just above the ice chute. 
         [0007]    One example of a solution to the aforementioned problem is disclosed in U.S. Pat. No. 3,640,089 to Frazier. The Frazier patent discloses a dispenser and crusher having a safety system for stopping operation of the dispenser and crusher upon the thrusting of an arm or other elongated member into a chute region. The safety system includes a proximity detection circuit having a sensing plate associated with the ice passage. However, Frazier does not distinguish between a human hand and other objects that may be inserted into the ice chute. 
         [0008]    Regardless of the existence of various known devices and methods for detecting foreign objects in an ice chute, there is still a need for further advancements in ice and liquid dispenser control. More specifically, there exists a need for a more versatile ice and liquid dispenser safety system that employs digital imaging technology and which is capable of sensing the presence of human skin, thus a human hand, in the dispensing area. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention is concerned with a refrigerator including a cabinet having top, bottom, rear and opposing side walls that collectively define a refrigerator body having a freezer compartment. The refrigerator further includes a door mounted to the cabinet for selectively providing access to the freezer compartment. The freezer compartment is provided with an ice maker, with the formed ice being stored in an ice cube storage bin. An ice crushing mechanism and ice chute are provided below the ice storage bin for dispensing ice to a service station. In accordance with the invention, the refrigerator employs an ice and liquid dispensing control system that utilizes digital images to determine if a person has inserted his or her hand into the dispensing station. 
         [0010]    More specifically, the ice and liquid dispensing control system employs a digital image capture device which is focused upon a well of the dispensing station. The digital image capture device captures digital images of objects that enter an upper region of the dispensing well. The digital images are sent to a digital image analyzing system that analyzes the image to determine if human skin color is present in the image. 
         [0011]    In further accordance with the present invention, if the digital image capture device determines that human skin color is present in the image, a controller signals a user interface to generate audible or visual notifications that a person has inserted his or her hand into an upper region of the ice and liquid dispensing well. 
         [0012]    Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0013]      FIG. 1  is a front elevational view of a refrigerator incorporating an ice and liquid dispensing system incorporating an imaging system constructed in accordance with the present invention; 
           [0014]      FIG. 2  is a fragmentary perspective view illustrating a freezer compartment of the refrigerator with the freezer door open; 
           [0015]      FIG. 3  is a fragmentary, side sectional view of the ice and liquid dispensing system of  FIG. 1 ; 
           [0016]      FIG. 4  is a block diagram illustrating a digital image capture device of the imaging system used to capture images of objects that enter the dispensing area in accordance with the present invention; and 
           [0017]      FIG. 5  is a flow chart illustrating the dispensing method according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0018]    With initial reference to  FIG. 1 , a refrigerator constructed in accordance with the present invention is generally indicated at  2 . Refrigerator  2  includes a cabinet  4  having a top wall  6 , a bottom  7  and opposing side walls  8  and  9 . In a manner known in the art, refrigerator  2  includes a freezer compartment  11  arranged along side a fresh food compartment  12 . Freezer compartment  11  includes a corresponding freezer compartment door  14  and fresh food compartment  12  includes a corresponding fresh food compartment door  15 . In a manner also known in the art, each door  14 ,  15  includes an associated handle  17 ,  18 . Refrigerator  2  is also shown to include a kick plate  20  arranged at a bottom portion thereof having a vent  21  that permits air to flow into refrigeration components (not shown) that establish and maintain desired temperatures in freezer compartment  11  and fresh food compartment  12 . In the embodiment shown, refrigerator  2  constitutes a side-by-side model. However, it should be understood that the present invention could also be employed in connection with a wide variety of refrigerators, including top mount, bottom mount, and French-style refrigerator models. 
         [0019]    As illustrated in  FIG. 2  an ice making assembly  22  is disposed within the freezer compartment  16  and may be mounted to top wall  24  of the freezer compartment  16  as shown, to a side wall, or on freezer door  20 , with each of these mounting arrangements also being known in the art. Preferably, ice making assembly  22  takes the form of a conventional ice piece making apparatus and produces generally crescent shaped ice pieces as depicted in  FIG. 2 . The ice makers disclosed in U.S. Pat. Nos. 4,649,717 and 5,160,094, herein incorporated by reference, are illustrative of the type of ice makers which may be used in accordance with the present invention. 
         [0020]    An ice dispensing system  26 , mounted to the freezer door  20 , is provided below the ice making assembly  22  for receiving ice pieces. The ice dispensing system  26  includes an ice bucket or bin  28 , as well as a lower ice crushing system  30 . When operated, the ice dispensing system  26  transfers ice pieces from bin  28  to ice crushing system  30  and then through the freezer door  14  whereby ice pieces may be dispensed through a forwardly exposed, external ice and liquid dispenser station or area  31 . More particularly, as shown in  FIG. 3 , an auger  32  positioned within ice bucket  28  causes the ice pieces to pass through an inlet opening and fall into the ice crushing region  30 . Rotation of auger  32  rotates crushing blades  35  resulting in the ice pieces being crushed. The crushed ice pieces, once past blades  35 , fall through an outlet opening  38 . Once the ice pieces, in either a whole or crushed form, are passed through the ice outlet opening  38 , they fall through an ice chute  40  formed into the freezer door  14  to a waiting receptacle positioned within the service area  31 . Ice chute  40  includes an entry end  41  positioned adjacent to crushing blades  35  and an ice dispensing end  42  positioned to eject ice into the service area  31 . 
         [0021]    In accordance with the invention, external ice and liquid dispenser station  31  includes a main housing  44  and a control panel  49 . Control panel  49  includes first and second rows of control buttons  53  and  54  which enable a user to select a preferred dispensing operation. Control panel  49  further includes a display  57 , such as an LCD display, which, in addition to functioning in cooperation with external ice and liquid dispenser station  31 , enables the user to select particular operational parameters for refrigerator  2 , such as desired temperatures for freezer compartment  11  and fresh food compartment  12 . In any case, external ice and liquid dispenser station  31  includes a dispenser well  63  having a base or container support portion  65  and a recessed, upstanding wall section  68 . Refrigerator  2  also includes an ice and liquid dispenser control system  75  for recognizing and sending an alert when a hand is in the dispensing well or ice chute. 
         [0022]    Dispenser control system  75  automatically detects when a user has inserted a body part, particularly a hand, into at least an upper rear portion of dispenser well  63 , particularly dispensing chute  40 . Towards that end, dispenser control system  75  includes a digital image capture device  78  and a digital image analyzer  80 , each of which is operatively coupled to a controller  85 . Basically, digital image capture device detects and images objects which enter dispenser well  63 . Digital images from digital image capture device  78  are passed to digital image analyzer  80  which calibrates the image and performs color and threshold based segmentation of the image in order to detect the presence of skin color in the image. If digital image analyzer  80  determines that human skin color is present in the image, the results are sent back to controller  85  which produces a signal to alert those nearby that a child or other user has inserted his or her hand into at least an upper rear region of dispenser well  63 , including dispensing chute  40 . The signal is preferably visually presented on display  57 , but may include an audible signal. In addition, controller  85  prevents any dispensing operation. In the event that digital image analyzer system  80  determines that human skin color is not found on the image, controller  85  enables dispensing to occur, such as through the operation of ice dispensing system  26 . However, if during the dispensing process, an updated image reveals a hand is now present, the dispensing process will be disabled. 
         [0023]    As best shown in  FIG. 4 , digital image capture device  78  preferably constitutes a digital camera that can take on a variety of forms, such as a fixed image charged/coupled device (CCD) camera, a fixed image complimentary metal oxide semiconductor (CMOS) camera or even a video camera. Digital image capture device  78  is preferably operatively connected to a light source  90  which produces light of one or more wavelengths. That is, light source  90  can bathe dispenser well  63  in white light, colored light or non-visible light depending upon a particular parameter of interest. In any case, digital image capture device  78  is angled and operated to capture digital images of objects that enter dispenser well  63 . Objects in dispenser well  63  are contrasted against a reference image, e.g., the background of dispenser well  63 , for clarity. In the depicted embodiment, digital image capture device  78  is positioned in an upper portion of dispenser well  63  to capture a side view of objects which may be above a container  91 . 
         [0024]    In accordance with a preferred control arrangement represented in  FIG. 5 , digital image capture device  78  first takes a photograph, i.e., captures a digital image, of an object that enters dispenser well  63  as shown in block  100 . The digital image is analyzed by digital image analyzing system  80  to determine if skin is present in the image. More specifically, an image processing algorithm is carried out to determine if skin is detected in the image. That is, in block  105 , the image is first subjected to an image correction step to correct distortions in the image, such as distortions that result from the use of a fish eye lens in image capture device  78 . The corrected image then undergoes color based segmentation and threshold based segmentation as shown in block  110 . Following segmentation, the image segments are subjected to a clustering process in block  115  to determine a mean cluster. The resulting images are then analyzed to determine if skin color is detected in block  120 . More specifically, the disclosed embodiment determines if the mean cluster is greater than a predetermined threshold. If the threshold is exceeded, there is an indication of skin color in the image and dispensing is prevented (step  125 ). If the mean cluster is not greater than the threshold, the control system enables a dispensing operation (also step  125 ). Although not shown in this figure, if the threshold is exceeded, a signal is also preferably passed to display  54  in connection with step  125  to provide notice that human skin, presumably a hand, is present in dispenser well  63 . 
         [0025]    Based on the above, it should be readily understood that the present invention enables a refrigerator to automatically detect and provide an alert when a human hand or the like has been inserted into the dispensing well. In addition to sending an alert, the system of the present invention provides for the automatic shut down of the dispensing system if the presence of a hand is detected. Although described with reference to preferred embodiments of the invention, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, it should be understood that the number and location of cameras can vary in accordance with the present invention. For example, cameras can be located within or simply exposed to the ice chute to capture digital images. In general, the invention is only intended to be limited by the scope of the following claims.