Patent Publication Number: US-11376858-B2

Title: Statuses of fill ports

Description:
BACKGROUND 
     Imaging systems, such as printers, copiers, etc., may be used to form markings on a physical medium, such as text, images, etc. In some examples, imaging systems may form markings on the physical medium by performing a print job. A print job can include forming markings such as text and/or images by transferring a print substance (e.g., ink, toner, etc.) to the physical medium. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an example imaging device consistent with the disclosure. 
         FIG. 2  illustrates an example device consistent with the disclosure. 
         FIG. 3A  illustrates an example fill port including a fill port cover consistent with the disclosure. 
         FIG. 3B  illustrates an example fill port consistent with the disclosure. 
         FIG. 3C  illustrates an example fill port including a colorant container consistent with the disclosure. 
         FIG. 4  illustrates an example of a controller consistent with the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Imaging devices may include a supply of a print substance located in a reservoir. The print substance can be deposited onto a physical medium. As used herein, the term “imaging device” refers to any hardware device with functionalities to physically produce representation(s) (e.g., text, images, models, etc.) on a medium. In some examples, a “medium” may include paper, photopolymers, plastics, composite, metal, wood, or the like. 
     The reservoir including the print substance may be inside of the imaging device and contain a supply of the print substance such that the imaging device may draw the print substance from the reservoir as the imaging device creates the physical representations on the print medium. As used herein, the term “reservoir” refers to a container, a tank, and/or a similar vessel to store a supply of the print substance for use by the imaging device. 
     An imaging device may include more than one reservoir such that various types (e.g., various colors) of print substance may be contained within the imaging device. Each reservoir containing the print substance may be connected to a fill port such that a user may fill the reservoir as the supply of print substance is used by the imaging device. As used herein, the term “fill port”, refers to an aperture, an area, and/or other opening connected to a print substance reservoir that receives a print substance and transfers the received print substance to the print substance reservoir (e.g., to replenish the print substance supply) included in the imaging device. 
     Each fill port may be accessible from the exterior of the imaging device such that a user may access the fill port to fill and/or re-fill the reservoir with the appropriate print substance as the volume of the print substance in the reservoir decreases. In some imaging devices, each fill port may include a corresponding fill port cover. As used herein, the term “fill port cover”, may refer to an object that may obstruct a fill port, an aperture, an area, and/or an opening such that the fill port is obstructed. The fill port cover can protect the contents of the reservoir from the external environment. 
     A fill port cover may be opened in order to transfer print substance to the print substance reservoir. In some examples, a fill port cover may be left open after filling and/or refilling the reservoir. While the fill port cover can prevent a print substance from evaporating and/or becoming contaminated (e.g., by dust or other contaminants), a fill port cover having been left open may lead to the print substance evaporating and/or being contaminated. In other words, when a fill port cover is left in an open position, the print substance may be exposed to external elements which may have a detrimental effect on the print substance performance and/or the fill port assembly. 
     Some imaging devices may not include reservoirs that indicate a type of print substance in the reservoir or how much print substance is in the reservoir. Thus, when the user attempts to fill a reservoir with a supply of the print substance, a potential for error (e.g., overfilling, refill of the wrong type, etc.) can exist. In other examples, some imaging devices may include multiple print substance reservoirs each having corresponding fill ports. An imaging device with multiple reservoirs result in tedious and complex print substance filling operations. 
     Statuses of fill ports according to the disclosure can include a detection circuit to detect a status of each fill port included on the imaging device. As used herein, the term “fill port status” refers to a condition of the fill port. The condition of the fill port can include being open or being closed. The fill port can be closed via the fill port cover or via a colorant container being connected to the fill port. As used herein, the term “colorant container” can refer to a vessel, bottle, bag, box, carton, or other suitable receptacle for the transfer and/or containment of a print substance. The colorant container can be used to fill or refill a reservoir connected to the fill port, as is further described herein. 
     The detection circuit can provide a scheme to unambiguously determine the fill port status of the fill ports included in an imaging device. The detection circuit may include a mechanical and/or electronic switch electrically connected at each fill port to detect when a fill port is open or closed (e.g., by a fill port cover or having a colorant container connected thereto). The detection circuit may provide a signal to a controller of the imaging device, and the imaging device may provide instructions to a user via a user interface regarding the detected status. The instructions provided to the user can help the user to determine whether the reservoir is full of print substance, whether print substance should be added to the reservoir, whether a supply of the print substance is connected to a correct fill port to deliver a correct type of print substance to a corresponding reservoir, and/or a fill port status including whether the fill port is open or closed, among other types of instructions. 
       FIG. 1  illustrates an example imaging device consistent with the disclosure. As illustrated in  FIG. 1 , an imaging device  100  may include a detection circuit  102 , a controller  104 , a plurality of fill ports  106 - 1 ,  106 - 2 ,  106 - 3 ,  106 -N (referred to collectively as fill ports  106 ), plurality of switches  110 - 1 ,  110 - 2 ,  110 - 3 ,  110 -N (referred to collectively as switches  110 ), and pull-down resistor  112 . 
     The imaging device  100  can include fill ports  106 . The plurality of fill ports  106  may be used to fill and/or refill a reservoir with a print substance that can be utilized by the imaging device  100 , as described above. Although not shown in  FIG. 1  for clarity and so as not to obscure examples of the disclosure, the imaging device  100  may include a corresponding reservoir connected to each fill port of the plurality of fill ports  106 . 
     Each of the fill ports  106  can include a fill port cover. For example, as described above, the fill port cover can cover a fill port such that the print substance included in a reservoir connected to the fill port does not evaporate and/or become contaminated. However, in order to perform a fill operation for the reservoir, the fill port cover can be removed to expose a fill port. The fill port cover of each of the fill ports  106  can include a resistor. As used herein, the term “resistor” refers to an electrical component of a circuit that engenders electrical resistance (e.g., to restrict or reduce current flow). 
     The resistor of each fill port cover can have a different resistance value. For example, the fill port cover of fill port  106 - 1  can include a resistance value that is different than the fill port covers of fill ports  106 - 2 ,  106 - 3 ,  106 -N, etc. In some examples, the resistor of the fill port cover of fill port  106 - 1  can be 50 k Ohms, the resistor of the fill port cover of fill port  106 - 2  can be 100 k Ohms, the resistor of the fill port cover of fill port  106 - 3  can be 200 k Ohms, and the resistor of the fill port cover of fill port  106 -N can be 400 k Ohms, although examples of the disclosure are not so limited to the above resistance values. 
     As the print substance included in the reservoir is utilized by imaging device  100 , the amount of print substance included in the reservoirs can be depleted. A fill operation may be performed to fill and/or re-fill the amount of print substance in the reservoirs. During a fill operation (e.g., the activity of a user or machine filling the reservoir with a print substance), a user may open a fill port cover to expose one of the fill ports  106 . 
     When one of the plurality of fill port covers is opened to expose a fill port, a switch (e.g., switches  110 ) electrically connected to the fill port cover can be opened. For example, as a result of a fill port cover being opened to expose fill port  106 - 1 , switch  110 - 1 , which is electrically connected to fill port  106 - 1 , can be opened. In other words, a state of the switch  110  can be changed. 
     As illustrated in  FIG. 1 , imaging device  100  can include detection circuit  102 . As used herein, the term “detection circuit” refers to an electrical circuit which can be utilized to determine a state of a fill port. For example, detection circuit  102  can be utilized to determine whether fill ports  106  are open or closed. In an example in which fill ports  106  are closed, detection circuit  102  can be utilized to determine whether fill ports  106  are closed via fill port covers or have colorant containers connected thereto. As illustrated in  FIG. 1 , detection circuit  102  can include switches  110  and pull-down resistor  112 , as is further described herein. 
     As used herein, the term “switch” refers to an electrical component which can break an electrical circuit, such as interrupting a current in the electrical circuit and/or diverting the current from one component to another. For example, when the fill port cover of fill port  106 - 1  is opened, switch  110 - 1  corresponding to fill port  106 - 1  can be opened, causing a change in the state of the switch  110 - 1 . As used herein, the term “switch state” refers to a condition of the switch. A condition of the switch  110  can include an open switch state or a closed switch state. As used herein, the term “open state” refers to a condition in which the switch has interrupted a current in the electrical circuit including the switch. As used herein, the term “closed state” refers to a condition in which current can pass through the electrical circuit including the switch. For example, when the fill port cover of fill port  106 - 1  is opened, the switch  110 - 1  can change from closed (e.g., in which current is flowing through switch  110 - 1 ) to open (e.g., in which switch  110 - 1  interrupts a flow of current to fill port  106 - 1 . 
     As described above, the switch state of switch  110 - 1  can be closed when a fill port cover of fill port  106 - 1  is closed, protecting the print fluid in the reservoir connected to fill port  106 - 1  from evaporating or from contaminants. However, examples of the disclosure are not so limited. For example, the switch state of switch  110 - 1  can be closed when a colorant container is connected to fill port  106 - 1 , as is further described herein. 
     The controller  104  can perform a detection process to determine a state of fill ports  106 . As used herein, the term “detection process” refers to a process to determine whether a fill port is open, whether a fill port is closed via a fill port cover, and/or whether a fill port is closed via a colorant container. 
     The controller  104  can perform the detection process by connecting a clock signal of imaging device  100  to a first fill port  106 - 1  of the fill ports  106  via detection circuit  102 . As used herein, the term “clock signal” refers to a signal that oscillates between a high and a low state at a particular frequency. In some examples, the clock signal can be generated by a dock generator included in imaging device  100 , although examples of the disclosure are not limited to a clock generator. In some examples, the clock signal can be an i2C clock signal. As used herein, the term “i2C” refers to a serial communications protocol. The clock signal can be multi-purpose. In some examples, the clock signal can be utilized to read a colorant container acumen to determine information related to the contents, manufacturing, etc. of the colorant container, as is further described in connection with  FIG. 3C . In some examples, the dock signal can be utilized as a general-purpose input. The voltage of the general-purpose input clock signal can be measured by an analog-to-digital (ADC) converter, or by other means. The measured voltage can be transmitted to controller  104 , as is further described herein. 
     The controller  104  can determine the state of first switch  110 - 1 . For example, controller  104  can determine whether first switch  110 - 1  is open or closed. Based on the state of first switch  110 - 1 , controller  104  can determine whether fill port  106 - 1  is open or closed, as is further described herein. 
     In one example, controller  104  can determine that fill port  106 - 1  is open. Controller  104  can determine that fill port  106 - 1  is open based on the state of switch  110 - 1 . For example, controller  104  can determine that switch  110 - 1  is in an open state. Switch  110 - 1  being in an open state can correspond to switch  110 - 1  having interrupted a current in the electrical circuit including switch  110 - 1 . 
     Based on the open state of switch  110 - 1 , controller  104  can determine that fill port  106 - 1  is open. That is, the open state of switch  110 - 1  can correspond to fill port  106 - 1  being open. Since switch  110 - 1  is in an open state, controller  104  can determine that fill port  106 - 1  is open. For example, as described above, a user can remove the fill port cover of fill port  106 - 1 , which can cause switch  110 - 1  to be in an open state, allowing controller  104  to determine the fill port cover of fill port  106 - 1  has been removed. 
     In another example, controller  104  can determine that fill port  106 - 1  is closed. Controller  104  can determine that fill port  106 - 1  is closed based on the state of switch  110 - 1 . For example, controller  104  can determine that switch  110 - 1  is in a closed state. Switch  110 - 1  being in a closed state can correspond to switch  110 - 1  allowing current to pass through the electrical circuit including switch  110 - 1 . 
     Based on the closed state of switch  110 - 1 , controller  104  can determine that fill port  106 - 1  is closed. That is, the closed state of switch  110 - 1  can correspond to fill port  106 - 1  being closed. Since switch  110 - 1  is in a closed state, controller  104  can determine that fill port  106 - 1  is closed. 
     As described above, fill port  106 - 1  can be closed in two ways. In one example, fill port  106 - 1  can be closed via a fill port cover. In another example, fill port  106 - 1  can also be closed as a result of a colorant container being connected to fill port  106 - 1 . Controller  104  can determine whether the fill port  106 - 1  is closed via the fill port cover or via the colorant container being connected to fill port  106 - 1 , as is further described herein. 
     Controller  104  can measure the voltage of the clock signal to determine whether fill port  106 - 1  is closed via a fill port cover or via a colorant container being attached. As used herein, the term “voltage” refers to a difference in electric potential between two points of an electrical circuit. Controller  104  can measure the voltage of the clock signal at switch  110 - 1  to determine whether fill port  106 - 1  is closed via a fill port cover or via a colorant container being connected thereto. For example, the voltage of the clock signal can be measured by an ADC and utilized by controller  104  to determine whether fill port  106 - 1  is closed. 
     Controller  104  can determine that fill port  106 - 1  is closed via a colorant container in response to the voltage of the clock signal being a first voltage. For example, controller  104  can measure the voltage of the clock signal to be 0 volts (V). Based on the voltage of the clock signal being 0V, controller  104  can determine that fill port  106 - 1  has a colorant container connected thereto. 
     As described above, the first voltage can be a first voltage. The first voltage can be a predetermined voltage (e.g., 0V). The first voltage can be a predetermined voltage of 0V which can indicate that a colorant container is connected to fill port  106 - 1 . Although the first voltage is described above as being 0V, examples of the disclosure are not so limited. For example, the first voltage can be any other predetermined voltage. For example, the first voltage can be 1V, or a voltage less than 1V or higher than 1V. 
     As illustrated in  FIG. 1 , detection circuit  102  can include a pull-down resistor  112 . For example, pull-down resistor  112  can cause the voltage of the clock signal of imaging device  100  to be the predetermined first voltage when the colorant container is connected to and covering fill port  106 - 1 . In other words, pull-down resistor  112  can cause the voltage of the clock signal of imaging device  100  to be the first voltage of 0V when the colorant container is connected to and covering fill port  106 - 1 . The pull-down resistor  112  can be part of a resistor-divider network that can either pull-down the voltage to reference ground potential or pull-up the voltage to any other arbitrary value. The pull-down resistor  112  can establish a default signal voltage when the clock signal is serving as a voltage input and fill port  106  is not closed by a fill port cover. The pull-down resistor  112  and resistors included on fill port covers of each fill port  106  can form a voltage divider circuit. Controller  104  can utilize the voltage resulting from the voltage divider circuit to determine a fill port status, as is further described herein. 
     In some examples, pull-down resistor  112  can be a 10K ohm resistor. However, examples of the disclosure are not limited to a 10K ohm resistor. For instance, pull-down resistor  112  can be a resistor having a higher resistance than 10K ohms (e.g., 11K ohms) or a resistor having a lower resistance than 10K ohms (e.g., 9K ohms). 
     Controller  104  can determine that fill port  106 - 1  is closed via a fill port cover in response to the voltage of the clock signal being a second voltage. As described above, the fill port cover corresponding to fill port  106 - 1  can include a resistor having, for instance, a resistance value of 50 k Ohms. When the fill port cover having the 50 k Ohm resistor is connected to fill port  106 - 1 , the 50 k Ohm resistor can be connected to detection circuit  102 , forming a voltage divider with pull-down resistor  112 . As a result of the voltage divider, controller  104  can measure the voltage of the clock signal to be 3.3 volts (V). For example, pull-down resistor  112  can cause the voltage of the clock signal to be 3.3V when a fill port cover is connected to and covering fill port  106 - 1 . Based on the voltage of the clock signal being 3.3V, controller  104  can determine that fill port  106 - 1  has a fill port cover connected thereto. 
     As described above, the second voltage can be a second voltage. The second voltage can be a predetermined voltage (e.g., 3.3V). The second voltage can be a predetermined voltage of 3.3V which can indicate that a fill port cover is connected to fill port  106 - 1 . Although the second voltage is described above as being 3.3V, examples of the disclosure are not so limited. For example, the second voltage can be any other predetermined voltage. For example, the second voltage can be 2V, or a voltage less than 2V, or a voltage higher than 2V. The second predetermined voltage can be included in a table of predetermined voltage values, as is further described herein. 
     Controller  104  can perform the detection process sequentially for each fill port of the fill ports  106 . For example, once controller  104  has determined that fill port  106 - 1  is either open, closed via a fill port cover, or closed via a colorant container being connected thereto, controller  104  can determine whether fill port  106 - 2  is open, closed via a fill port cover, or closed via a colorant container being connected thereto, whether fill port  106 - 3  is open, closed via a fill port cover, or closed via a colorant container being connected thereto, whether fill port  106 -N is open, closed via a fill port cover, or closed via a colorant container being connected thereto, etc. 
     For instance, in response to fill port  106 - 2  being closed, controller  104  can perform the detection process by directing the clock signal of imaging device  100  to fill port  106 - 2  via the detection circuit  102 . Controller  104  can measure the voltage of the clock signal at switch  110 - 2 , which is electrically connected to fill port  106 - 2 , to determine whether fill port  106 - 2  is closed via a fill port cover or via a colorant container being connected thereto. The clock signal can be an input signal to detection circuit  102 , and controller  104  can measure the voltage of the clock signal using an ADC, among other ways to measure the voltage of the clock signal. 
     Fill port  106 - 2  can be determined to be closed via a colorant container. For example, controller  104  can measure the voltage of the clock signal to be a first voltage, where the first voltage corresponds to a colorant container being attached to fill port  106 - 2 . As described above, the first voltage can be 0V. For example, controller  104  can measure the voltage of the clock signal to be 0V and as a result, determine that a colorant container is connected to fill port  106 - 2 . In some examples, controller  104  can additionally query a memory device connected to the colorant container to confirm the presence of the colorant container. Based on controller  104  receiving a signal from the memory device (e.g., a colorant container acumen) as a result of the query, controller  104  can determine that a colorant container is connected to fill port  106 - 2 . 
     Fill port  106 - 2  can be determined to be closed via a fill port cover. As described above, the fill port cover corresponding to fill port  106 - 2  can include a resistor having, for instance, a resistance value of 100 k Ohms. When the fill port cover having the 100 k Ohm resistor is connected to fill port  106 - 2 , the 100 k Ohm resistor can be connected to detection circuit  102 , forming a voltage divider with pull-down resistor  112 . As a result of the voltage divider, controller  104  can measure the voltage of the clock signal to be a second voltage, where the second voltage corresponds to a fill port cover being attached to fill port  106 - 2 . As described above, the second voltage can be 5V. For example, controller  104  can measure the voltage of the clock signal to be 5V and as a result, determine that a fill port cover is connected to fill port  106 - 2 . 
     In some examples, more than one fill port cover may be connected to fill ports  106 . For example, a fill port cover including a resistor having a resistance value of 50 k Ohms can be connected to fill port  106 - 1  and a fill port cover including a resistor having a resistance value of 200 k Ohms can be connected to fill port  106 - 3 . As a result of the fill port cover being connected to fill port  106 - 1  and the fill port cover being connected to fill port  106 - 3 , the 50 k Ohm resistor and the 200 k Ohm resistor can be connected to the detection circuit  102 , forming a voltage divider with pull-down resistor  112 . As a result of the voltage divider, controller  104  can measure the voltage of the clock signal to be a predetermined voltage. For example, pull-down resistor  112  can cause the voltage of the clock signal to be 10V when a fill port cover is connected to and covering fill port  106 - 1  and when a fill port cover is connected to and covering fill port  106 - 3 . Based on the voltage of the clock signal being 10V, controller  104  can determine that fill port  106 - 1  and fill port  106 - 3  have fill port covers connected thereto. In other words, controller  104  can compare the measured clock signal voltage with a table of predetermined values to determine which fill ports  106  are closed via fill port covers. 
     The table of predetermined values can include all combinations of voltages corresponding to all combinations of fill ports  106  being closed by fill port covers based on the resistance values of the resistors included in each fill port cover. For example, imaging device  100  can include four fill ports  106 - 1 ,  106 - 2 ,  106 - 3 ,  106 -N. As a result, a total of sixteen combinations of fill port statuses of closed via fill port covers are possible. Each of the sixteen combinations can include a unique predetermined voltage value that controller  104  can compare the voltage of the clock signal against to determine which fill ports  106  are closed via fill port covers. 
     For example, Table 1 (below) illustrates combinations of fill ports  106  being closed via fill port covers. Controller  104  can compare the clock signal voltage to the predetermined table of voltage values to determine which fill ports  106  are closed via fill port covers. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Fill Port Status 1 = Closed 0 = Open 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Predetermined 
               
               
                 106-1 
                 106-2 
                 106-3 
                 106-N 
                 Value 
               
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 0 
                 0 
                 0 
                 0 
                 0 
               
               
                 0 
                 0 
                 0 
                 1 
                 8 
               
               
                 0 
                 0 
                 1 
                 0 
                 16 
               
               
                 0 
                 0 
                 1 
                 1 
                 24 
               
               
                 0 
                 1 
                 0 
                 0 
                 32 
               
               
                 0 
                 1 
                 0 
                 1 
                 40 
               
               
                 0 
                 1 
                 1 
                 0 
                 48 
               
               
                 0 
                 1 
                 1 
                 1 
                 56 
               
               
                 1 
                 0 
                 0 
                 0 
                 64 
               
               
                 1 
                 0 
                 0 
                 1 
                 72 
               
               
                 1 
                 0 
                 1 
                 0 
                 80 
               
               
                 1 
                 0 
                 1 
                 1 
                 88 
               
               
                 1 
                 1 
                 0 
                 0 
                 96 
               
               
                 1 
                 1 
                 0 
                 1 
                 104 
               
               
                 1 
                 1 
                 1 
                 0 
                 112 
               
               
                 1 
                 1 
                 1 
                 1 
                 120 
               
               
                   
               
            
           
         
       
     
     The predetermined values illustrated above in Table 1 can, in some examples, be an arbitrary value assigned to each voltage combination, each voltage-divider ratio, or in some examples, can be actual voltages or voltage divider ratios. The predetermined values are illustrative and, as a result, examples of the disclosure are not so limited to the above predetermined values in Table 1. In some examples, the predetermined number illustrated in Table 1 can correspond to a voltage. For example, the predetermined value of 80 may correspond to a voltage of 5V. That is, controller  104  can measure a clock signal voltage to be 5V (e.g., caused by a voltage divider formed from pull-down resistor  112  and the resistors corresponding to the fill port covers connected to the particular fill ports), determine 5V to correspond to a predetermined value of 80, and using Table 1, determine that a fill port cover is connected to fill port  106 - 1  and a fill port cover is connected to fill port  106 - 3 . In other examples, the predetermined value of 80 may correspond to a particular voltage divider ratio. 
     Statuses of fill ports according to the disclosure can detect a status of a plurality of fill ports. A detection circuit included in an imaging device may protect the imaging device and print substance included in reservoirs contained therein by alerting a user to the status of the fill port as being open, closed via a fill port cover, or closed via a colorant container being connected thereto. In this way, the integrity of the fill ports and the print substance may be monitored and maintained. 
       FIG. 2  illustrates an example device  214  consistent with the disclosure. As illustrated in  FIG. 2 , a device  214  may include a detection circuit  202 , a controller  204 , a fill port  206 , a fill port cover  208 , pull-down resistor  212 , and a switch  210 . 
     As illustrated in  FIG. 2 , device  214  can include a detection circuit  202 . The detection circuit  202  can include a switch  210 . Switch  210  can be electrically connected to fill port  206 . 
     Device  214  can further include a controller  204 . Controller  204  can perform a detection process, as is further described herein. 
     For example, controller  204  can direct a clock signal of device  214  to fill port  206  via switch  210  and detection circuit  202 . The clock signal can, in some examples, be generated by a clock generator included in device  214 . Using the voltage of the clock signal, controller  204  can determine whether fill port  206  is open, closed via a fill port cover  208 , or closed via a colorant container using the detection process described herein. Controller  204  can direct the clock signal to fill port  206  via switch  210  via firmware control and/or via a general purpose input/output signal. 
     Controller  204  can determine whether fill port  206  is open or closed. Fill port  206  can be open when a reservoir including a print substance has to be filled or refilled. For instance, a user may remove a fill port cover  208  in order to fill or refill a reservoir with print substance. Although not illustrated in  FIG. 2  for clarity and so as not to obscure examples of the disclosure, the reservoir can be connected to fill port  206 . 
     Controller  204  can determine whether fill port  206  is open or closed based on a state of switch  210 . When switch  210  is in an open state (e.g., having interrupted a current in the electrical circuit), controller  204  can determine that fill port  206  is open. For example, a user may have removed fill port cover  208  in order to fill or refill the reservoir with print substance. When switch  210  is in a closed state (e.g., allowing current to pass through the electrical circuit including the switch), controller  204  can determine that fill port  206  is closed. However, controller  204  has not yet determined how fill port  206  is closed (e.g., the status of fill port  206 ). That is, the status of fill port  206  can indicate how fill port  206  is closed. For instance, fill port  206  can be closed via a fill port cover  208  or via a colorant container. 
     In response to the status of fill port  206  being closed, controller  204  can determine whether fill port  206  is connected to a colorant container. Controller  204  can determine whether fill port  206  is connected to a colorant container by determining the voltage of the clock signal. For example, if controller  204  determines the voltage of the clock signal to be a first voltage (e.g., 0V as a result of pull-down resistor  212 ), controller  204  can determine that a colorant container is connected to fill port  206 . Although not illustrated in  FIG. 2 , a colorant container can be connected to fill port  206  which can cause the voltage of the clock signal to be the first voltage. 
     In response to the status of fill port  206  being closed, controller  204  can determine whether fill port  206  is connected to a fill port cover  208 . Controller  204  can determine whether fill port  206  is connected to the fill port cover  208  by determining the voltage of the clock signal. For example, if controller  204  determines the voltage of the clock signal to be a second voltage (e.g., 3.3V as a result of pull-down resistor  212 ), controller  204  can determine that fill port cover  208  is connected to fill port  206 . 
       FIG. 3A  illustrates an example fill port including a fill port cover consistent with the disclosure. As illustrated in  FIG. 3A , fill port  306  can include a plurality of contacts  316 - 1 ,  316 - 2 ,  316 - 3 ,  316 - 4  (referred to collectively as contacts  316 ). Fill port cover  308  can include resistor  318 . 
     As previously described in connection with  FIGS. 1 and 2 , fill port  306  can be open, closed via a fill port cover (e.g., fill port cover  308 ), or closed via a colorant container being connected thereto. As illustrated in  FIG. 3A , fill port  306  can be closed. Fill port  306  can be closed via fill port cover  308 . In other words, fill port cover  308  can be connected to fill port  306  in order to prevent the print substance located in a reservoir connected to fill port  306  from evaporating and/or becoming contaminated. 
     As a result of fill port cover  308  being connected to fill port  306 , a resistor  318  can be connected to electrical contacts  316 . As used herein, the term “contacts” refers to an electrical circuit component comprising an electrically conductive material such that the material may communicatively couple to another electrical circuit component. As used herein, the term “communicatively coupled” refers to various wired and/or wireless connections between devices such that data and/or signals may be transferred in various directions between the devices. For example, resistor  318  can be connected to contacts  316 - 1  and  316 - 2  to allow current to flow between contacts  316 - 1  and  316 - 2 . In an example in which fill port  306  is open, resistor  318  is disconnected from contacts  316 - 1  and  316 - 2 , as is further described in connection with  FIG. 3B . Disconnecting resistor  318  can remove resistor  318  from the detection circuit (e.g., detection circuit  102 ,  202 , previously described in connection with  FIGS. 1 and 2 , respectively). 
     Although not illustrated in  FIG. 3A  for clarity and so as not to obscure examples of the disclosure, fill port  306  can be electrically connected to a switch. In the example illustrated in  FIG. 3A , the switch can be in a closed state. In other words, current can flow between the electrical contact  316 - 1 , resistor  318 , electrical contact  316 - 2 , and the switch. In the closed state illustrated in  FIG. 3A , a controller (e.g., controller  104 ,  204 , previously described in connection with  FIGS. 1 and 2 , respectively) can determine that the fill port  306  is in a closed state via fill port cover  308  being connected to fill port  306 . 
       FIG. 3B  illustrates an example fill port consistent with the disclosure. As illustrated in  FIG. 3B , fill port  306  can include a plurality of contacts  316 - 1 ,  316 - 2 ,  316 - 3 ,  316 - 4  (referred to collectively as contacts  316 ). 
     As illustrated in  FIG. 3B , fill port  306  can be open. In other words, fill port  306  is not connected to a fill port cover, nor is fill port  306  connected to a colorant container. 
     As a result of neither a fill port cover or a colorant container attached to fill port  306 , the switch connected to fill port  306  can be in an open state. For example, no current can flow between any of the electrical contacts  316 . As a result, the switch can be in an open state. 
       FIG. 3C  illustrates an example fill port including a colorant container consistent with the disclosure. As illustrated in  FIG. 3A , fill port  306  can include a plurality of contacts  316 - 1 ,  316 - 2 ,  316 - 3 ,  316 - 4  (referred to collectively as contacts  316 ). Colorant container  320  can include colorant container acumen  322 . 
     As a result of fill colorant container  320  being connected to fill port  306 , colorant container acumen  322  can be connected to electrical contacts  316 . As used herein, the term “colorant container acumen” refers to a memory device which can be attached to colorant container  320 . For example, colorant container acumen  322  may be attached to colorant container  320  and include information related to the contents, manufacturing etc. of the colorant container. 
     Although not illustrated in  FIG. 3C  for clarity and so as not to obscure examples of the disclosure, fill port  306  can be electrically connected to a switch. In the example illustrated in  FIG. 3C , the switch can be in a closed state. In other words, current can flow between the electrical contacts  316 , colorant container acumen  322 , and the switch. In the closed state illustrated in  FIG. 3C , a controller (e.g., controller  104 ,  204 , previously described in connection with  FIGS. 1 and 2 , respectively) can determine that the fill port  306  is in a closed state via colorant container  320  being connected to fill port  306 . 
     In some examples, the controller can probe fill port  306  to query colorant container acumen  322  that may be attached to colorant container  320 . For example, the controller can probe colorant container acumen  322  to determine information related to the contents, manufacturing, etc. of the print substance included in colorant container  320 . 
     In some examples, the presence of the colorant container  320  at fill port  306  may be further verified by the controller collecting data about the colorant container  320 . The controller can probe fill port  306  and if colorant container  320  is present, a detection circuit (e.g., detection circuit  102 ,  202 , previously described in connection with  FIGS. 1 and 2 , respectively) may transmit data related to the colorant container  320  from colorant container acumen  322  to the controller. In this way, the detection circuit may communicate this data to the imaging device to be used to provide guidance to a user. For example, the imaging device can tell a user the colorant container  320  is installed correctly/incorrectly, whether the colorant container  320  includes a correct or incorrect type of print substance, an amount of print substance in the reservoir connected to the fill port  306 , among other guidance. 
       FIG. 4  illustrates an example controller  404  consistent with the disclosure. As illustrated in  FIG. 4 , the controller  404  may include a processing resource  424 , and a memory resource  426 . As used herein, the processing resource  424  may be a central processing unit (CPU), a semiconductor-based microprocessor, and/or other hardware devices suitable for retrieval and execution of instructions stored in non-transitory computer readable medium (e.g., the memory resource  426 ). The processing resource  424  may fetch, decode, and execute instructions  428 ,  430 ,  432 ,  434 . As an alternative or in addition to retrieving and executing instructions, the processing resource  424  may include an electronic circuit that includes electronic components for performing the functionality of instructions. As used herein, the memory resource  426  may also be referred to a non-transitory computer readable medium, and may be a volatile memory (e.g., RAM, DRAM, SRAM, EPROM, EEPROM, etc.) and/or non-volatile memory (e.g., a HDD, a storage volume, data storage, etc.) Although the following descriptions refer to a single processor and a single memory, the descriptions may also apply to a system with multiple processors and multiple memories. In such examples, the instructions may be distributed (e.g., stored) across multiple memories and the instructions may be distributed (e.g., executed by) across multiple processors. 
     The controller  404  may include instructions  428  stored in the memory resource  426  and executable by the processing resource  424  to direct a clock signal of an imaging device to a fill port. That is, processing resource  424  can execute instructions  428  stored in the memory resource  426  to direct a clock signal of an imaging device to a fill port via a detection circuit of the imaging device. Using the voltage of the clock signal, controller  404  can determine whether the fill port is open, closed via a fill port cover, or closed via a colorant container, as is further described herein. 
     The controller  404  may include instructions  430  stored in the memory resource  426  and executable by the processing resource  424  to determine whether the fill port is open or closed. That is, processing resource  424  can execute instructions  430  stored in the memory resource  426  to determine, based on the state of a switch included in the detection circuit, whether the fill port is open or closed. When the switch is in an open state, controller  404  can determine that the fill port is open. For example, a user may have removed a fill port cover in order to fill or refill a reservoir connected to the fill port with print substance. When the switch is in a closed state, the controller  404  can determine that the fill port is closed. 
     The controller  404  may include instructions  432  stored in the memory resource  426  and executable by the processing resource  424  to determine a status of the fill port. That is, processing resource  424  can execute instructions  432  stored in the memory resource  426  to determine, based on the state of the switch indicating the fill port is closed, a status of the fill port. The status of the fill port can indicate how the fill port is closed. For example, the fill port can be closed via a fill port cover or via a colorant container. Therefore, the fill port status can refer to the fill port being closed via the fill port cover or being closed via the colorant container. 
     The controller  404  may include instructions  434  stored in the memory resource  426  and executable by the processing resource  424  to determine whether the fill port is connected to a colorant container. That is, processing resource  424  can execute instructions  434  stored in the memory resource  426  to, in response to the status of the fill port being closed, determine based on a voltage of the clock signal whether the fill port is connected to a colorant container. For example, controller  404  can determine whether the fill port is connected to a colorant container by determining the voltage of the dock signal. If controller  404  determines the voltage of the clock signal to be a first voltage (e.g., 0V), controller  404  can determine that a colorant container is connected to the fill port. 
     In some examples, the controller  404  may include further instructions stored in the memory resource  426  and executable by the processing resource  424  to determine whether the fill port is connected to a fill port cover. For example, controller  404  can determine whether the fill port is connected to a fill port cover by determining the voltage of the clock signal. If controller  404  determines the voltage of the clock signal to be a second voltage (e.g., 3.3V), controller  404  can determine that a fill port cover is connected to the fill port. 
     Statuses of fill ports according to the disclosure can detect a status of a plurality of fill ports. Utilizing a detection circuit and a controller, an imaging device can guide and/or alert a user to the status of the fill port as being open, closed via a fill port cover, or closed via being connected to a colorant container. In this way, the integrity of the fill ports and the print substance may be monitored and maintained. The determined status of the fill ports may be used by the imaging device to protect the reservoir, as well as the print substance included therein, from environmental elements such as evaporation and/or contaminants. Further, the controller may cause this information to be communicated to a user via a user interface to provide guidance or warning regarding a status of a fill port. 
     In the foregoing detailed description of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration how examples of the disclosure may be practiced. These examples are described in sufficient detail to enable those of ordinary skill in the art to practice the examples of this disclosure, and it is to be understood that other examples may be utilized and that process, electrical, and/or structural changes may be made without departing from the scope of the disclosure. 
     The figures herein follow a numbering convention in which the first digit corresponds to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar digits. For example,  102  may reference element “02” in  FIG. 1 , and a similar element may be referenced as  202  in  FIG. 2 . 
     Elements illustrated in the various figures herein can be added, exchanged, and/or eliminated so as to provide a plurality of additional examples of the disclosure. In addition, the proportion and the relative scale of the elements provided in the figures are intended to illustrate the examples of the disclosure and should not be taken in a limiting sense. As used herein, the designator “N”, particularly with respect to reference numerals in the drawings, indicates that a plurality of the particular feature so designated can be included with examples of the disclosure. The designators can represent the same or different numbers of the particular features. Further, as used herein, “a plurality of” an element and/or feature can refer to more than one of such elements and/or features. 
     The above specification, examples and data provide a description of the method and applications and use of the system and method of the present disclosure. Since many examples can be made without departing from the spirit and scope of the system and method of the present disclosure, this specification merely sets forth some of the many possible example configurations and implementations.