Patent Publication Number: US-2017357203-A1

Title: Printing Device Control Method and System with Executing Command Determined from Image

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of and claims the benefit of priority from U.S. patent application Ser. No. 14/551,405, filed Nov. 24, 2014, which is hereby incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     Unless otherwise indicated herein, the description in this background section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section. The present disclosure relates to a control method and system for a printing device, using the scanning functionality of the printing device to receive control information. 
     2. Description of the Related Art 
     Modern printing devices are becoming increasingly more complex with the addition of new functions, modes of use, and network connectivity. As a result, maintenance of modern printing devices has become more complicated and can require advanced skills and technical knowledge. 
     In most cases, maintenance of a modern printing device is carried out using the device&#39;s front panel to check and change various settings. For example, a device may need its memory cleared or its network settings changed. These operations are typically performed by a person physically located at the device, using the device&#39;s front panel. 
     In addition to requiring in-person maintenance, most modern printing devices require a specific set of commands that depend on the device&#39;s model, version, and supplying vendor. Thus, a technician performing maintenance may need to know many different sets of commands and settings particular to each modern printing device. 
     SUMMARY 
     In a first embodiment, a method for controlling a printing device is provided. The method preferably includes determining an image corresponding to a command for controlling a printing device. The command is for performing maintenance on the printing device. The method includes rendering the image on a portable medium. The method also includes reading, into the printing device, the image rendered on the portable medium. The method further includes determining that the image read into the printing device contains the command for controlling the printing device. The method yet further includes executing the command. 
     In a second embodiment, a system for controlling a printing device is provided. The system preferably includes a processing device and a printing device. The processing device is configured to determine an image corresponding to a command for controlling a printing device. The command is for performing maintenance on the printing device. The processing device is also configured to render the image on a portable medium. The printing device is configured to receive the image as an input. The printing device is also configured to determine that the image received as input contains the command for controlling the printing device. The printing device is further configured to execute the command contained in the image. 
     In a third embodiment, a printing device is provided. The printing device preferably includes a processor and a memory. The printing device further includes an image receiver that receives an image corresponding to a command for a printing device. The command is for performing maintenance on the printing device. The printing device also includes a command determiner for determining whether the received image contains the command for controlling the printing device. The printing device further includes a command executor for carrying out the command contained in the image. 
     Other embodiments, aspects, and implementations will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a printing device control system according to an embodiment of the present disclosure. 
         FIG. 2  is a block diagram illustrating a printing device control system according to an embodiment of the present disclosure. 
         FIG. 3  is a flowchart illustrating a method for controlling a printing device. 
         FIG. 4  is a flowchart illustrating a method for controlling a printing device according to an embodiment that includes encoding and decoding a command. 
         FIG. 5  is a flowchart illustrating a method for controlling a printing device according to an embodiment that includes encrypting and decrypting a command. 
         FIG. 6  is a schematic diagram illustrating the printer device control method according to an embodiment. 
         FIG. 7  is a schematic diagram illustrating the printer device control method according to an embodiment. 
         FIG. 8  is a schematic diagram illustrating the image generation and rendering according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying figures, which form a part hereof. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, figures, and claims, are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein. 
     I. Overview 
     The disclosure relates to methods, systems, and devices for controlling printing devices. Specifically, a system may include a processing device and a printing device. The processing device may be configured to determine an image that corresponds to a command. The command may be a command for performing maintenance on a printing device. The processing device may also be configured to render the image onto a portable medium. As used herein, a portable medium may be anything upon which an image can be rendered, such as paper, cardstock, or the display of an electronic device, such as a smart phone or tablet computer. The printing device may be configured to read the image that is rendered on the portable medium. The printing device may also be configured to determine that the read image includes a command. Further, the printing device may be configured to execute the command included in the image. 
     II. System Examples 
       FIG. 1  is a block diagram illustrating a printing device control system  100  according to an example embodiment. The system  100  may include a processing device  102 , a portable medium  130  having an image  132 , and a printing device  140 . The processing device  102  may include an image determiner  110  and an image renderer  120 . The printing device  140  may include an image receiver  150 , a command determiner  160 , and a command executor  170 . 
     In the following descriptions of the various components, the term memory may be used. The memory may take many different forms such as a hard disk drive (HDD), compact disc (CD), digital video disc (DVD), digital tape, or non-volatile flash memory such as a flash drive, secure digital (SD) card, or similar storage mediums. The memory may also be any form of volatile memory, including random access memory (RAM), for example. Further, the memory may be integrated with one or more of the described components, may be shared between one or more components (i.e., an internal memory for the entire device), or may be separate from the components. 
     The image determiner  110  in the processing device  102  may create an image that corresponds to a command for a printing device. Alternatively, the image determiner may select an image from a list of pre-generated images stored and/or generated locally or remotely (e.g. in a database accessible through a wired or wireless network connection). In some embodiments, the image determiner may determine the image based on an input from a user. Alternatively, the image determiner may determine the image based on some other source of input. 
     The image determiner  110  may include hardware, firmware, or a software application configured to determine an image corresponding to a command. The image determiner may also include a memory and a processor. For example, the image determiner  110  may include a set of program instructions stored on a memory that, when executed by a processor, causes an image corresponding to a command to be selected. The image determiner  110  may also include a user interface, such as a keyboard and/or mouse, which may allow a user to input an image selection. Further, the image determiner  110  may include a network interface, which may allow an image selection to be input by a remote device, such as a PC or tablet computer, over a wired or wireless network. 
     The image renderer  120  in the processing device  102  may render the image  132  onto the portable medium  130 . In some embodiments, the image renderer  120  may be a personal printer, a networked or shared printer, a virtual printer, or another type of printing device. Alternatively, the image renderer  120  may be comprised of a set of instructions on a computer-readable medium that, when executed, causes the image  132  to be displayed on a display screen of a portable electronic device. 
     The image renderer  120  may include hardware, firmware, or a software application configured to cause an image to be rendered on a portable medium, as well as memory and a processor. The image renderer may also include a print head, one or more ink cartridges, and a paper feed assembly (i.e. an inkjet printer). Alternatively, the image renderer  120  may include a laser printer assembly, having a laser scanning unit, photoreceptor drum, toner hopper, fuser, and developer roller (i.e., a laser printer). Further, the image renderer may include a set of program instructions stored on a memory that, when executed by a processor, causes an image to be displayed on a display screen. The display screen may include a liquid crystal display (LCD), light-emitting diode (LED) display, organic light-emitting diode (OLED) display, active-matrix organic light-emitting diode (AMOLED) display, Retina Display, or any other type of suitable display. 
     The portable medium  130  may be comprised of any material on which an image can be printed, displayed, or affixed. For example, the portable medium may be paper, or alternatively it may be a portable electronic device with a screen, as discussed above. In some embodiments, one or both of the image determiner  110  and image renderer  120  may be integrated with the portable medium  130 . For example a portable electronic device such as a smart phone or tablet computer may include a display screen, as well as instructions configured to carry out the acts described above in reference to the image determiner and/or image renderer. The image  132  may be any image or object (e.g. a 3D-printed object) that corresponds to a command for a printing device. For instance, the image may be in the form of a barcode or quick response (QR) code. 
     The image receiver  150  in the printing device  140  may read the image  132  into the printing device  140 . In at least one embodiment, the image receiver  150  is a scanner. The scanner may be a component of the printing device, for example, providing one function of a multifunction printing (MFP) device. As used herein, an MFP device is any printing device that, in addition to printing, can perform at least one other function such as scanning, copying, or faxing. Alternatively, the scanner may take the form of a scanning device physically separate from the printing device. In some embodiments, the image receiver  150  may take the form of a stand-alone or integrated scanner, digital camera, barcode scanner, or other electronic device that can read an image. An image receiver  150  that is physically separate from the printing device may be connected to the printing device via a wired or wireless data link or communication network. 
     The image receiver  150  in the printing device  140  may include hardware, firmware, or a software application configured to receive an image as input, as well as memory and a processor. The image receiver may include a set of program instructions stored on a memory that, when executed by a processor, causes an image to be read into the printing device. The image receiver may include mirrors, a lens, filters, a charge-coupled device (CCD) array, a lamp, a motor, a power supply, interface ports, and control circuitry (i.e. a flatbed scanner). In some embodiments, the image receiver may include one or more lenses, an aperture and shutter, filters, an analog-to-digital converter, a CCD array, a microprocessor, and a user interface (i.e., a digital camera). In other embodiments, the image receiver may include a pen-type or laser barcode scanner, which include a light source, a photo diode, a housing, and control circuitry. 
     The command determiner  160  in the printing device  140  may determine whether the image  132  read into the printing device  140  by the image receiver  150  contains a command for controlling the printing device. The command determiner  160  in the printing device  140  may include hardware, firmware, or a software application configured to determine whether a command is contained in the image read into the printing device, as well as a memory and a processor. 
     As an example, the command determiner  160  in the printing device  140  may include a plurality of predetermined supported commands, stored in a list, database, array, or other storage structure in the memory. The command determiner  160  may compare the information contained in the image (as opposed to the image itself) to the predetermined supported commands. Specifically, the command determiner may convert the image  132  read into the printing device into an alphanumeric code, based on the content of the image. For example, a barcode may be converted from a series of vertical lines to a numeric code based on the spacing and thickness of the lines. As another example, a QR code image may be converted to an alphanumeric code based on the size and positioning of the dots located in the image. The command determiner may then compare the numeric or alphanumeric code contained in the image to a predetermined list of codes stored in the memory (i.e. predetermined supported commands). The command determiner may determine there is a command included in the image if there is a match. 
     In another embodiment, the command determiner  160  may include a plurality of pre-determined images (e.g., barcodes or QR codes representing commands supported by the printing device) stored in a list, database, array, or other storage structure in the memory. The pre-determined images may be stored in any appropriate file format, such as JPEG, Exif, TIFF, RIF, GIF, BMP, or PNG, for example. The command determiner  160  may compare the image  132  read into the printing device to the plurality of stored images. The command determiner may then determine that there is a match, and therefore determine that a command is included in the image read into the printing device. 
     In still another embodiment, the command determiner may include a user interface. As such, the command determiner may determine that a command is included in an image read into the printing device by receiving an indication from a user through a user interface. 
     In some embodiments the image receiver  150  and/or command determiner  160  may be physically separate from the printing device, but connected to it via a wired or wireless connection such as Ethernet, Universal Serial Bus (USB), RS-232, Wi-Fi, local area network (LAN), wide area network (WAN), or any other communication network. 
     The command executor  170  in the printing device  140  may execute the command contained in the image  132  that has been read into the printing device  140 . The command executor may include hardware, firmware, or a software application configured to execute a command. The command executor may include one or more processors, such as general purpose processors, special purpose processors, microprocessors, or digital signal processors (DSPs), for example. The command executor may also include a set of program instructions stored on a memory that, when executed by a processor, cause the command executor to perform a command. As an example, where the command is a maintenance command such as ‘restart device,’ the command executor may cause the processor to execute the set of instructions that cause the printing device to restart. 
       FIG. 2  is a block diagram illustrating a printing device control system  200  according to an example embodiment. The system  200  may include the processing device  102 , the portable medium  130  having an image  132 , and the printing device  140  generally described above in connection with  FIG. 1 . In the system  200 , the processing device  102  may include an image determiner  110  and an image renderer  120 . In at least one embodiment, the processing device may also include a memory  202  and a processor  204 . The memory  202  may take many different forms such as a hard disk drive (HDD), compact disc (CD), digital video disc (DVD), digital tape, or non-volatile flash memory such as a flash drive, secure digital (SD) card, or similar storage mediums. The memory  202  may also be any form of volatile memory, including random access memory (RAM), for example. 
     In one or more embodiments, the image determiner  110  in the processing device  102  may include a command generator  206 . The command generator  206  may include hardware, firmware, or a software application configured to generate a command, as well as memory and a processor. For example, the command generator  206  may include a set of program instructions stored on a memory that, when executed by a processor, causes a command to be generated or selected. The command generator  206  may create a command, select a command from a pre-determined list of commands stored on a memory, or otherwise generate a command for controlling a printing device. In some embodiments, the printing device has a pre-determined set of application programming interface (API) commands that are supported. The command generator may select a command from this set of supported commands. Example commands for maintaining a printing device include causing a printing device to restart, clear memory, print out a status report, or set sleep mode. Many other commands are possible. The command generator may also include a user interface, such as a keyboard and/or mouse, which may allow a user to input a command selection. Further, the command generator  206  may include a network interface, which may allow a command selection to be input by a remote device, such as a PC or tablet computer, over a wired or wireless network. 
     In some embodiments, the image determiner  110  in the processing device  102  may include a command encoder  208 . The command encoder  208  may include hardware, firmware, or a software application configured to encode a command. The command encoder  208  may also include memory and a processor. The command encoder  208  may include a set of program instructions stored on a memory that, when executed by a processor, causes a command to be encoded. The command encoder  208  may encode the command into an alphanumeric format. As an example, the command ‘restart device’ may be encoded into the form ‘ 11 .’ The command encoder may also include encoding a command type, a check sum, any associated data, or other relevant information. 
     In one embodiment, the command encoder  208  may encode some or all of the possible commands prior to selection by the command generator  206 . The encoded commands may be stored on a memory as a list of encoded commands. In another embodiment, the command encoder  208  may dynamically encode a command after it is selected by the command generator. For example, generation of a given command may require additional information that is not available until the command is chosen, such as a command to print a status report (i.e., the report number may be required). In that case, the command encoder may use the selected command and other information, such as command type, check sum, and associated data (e.g., the report number), and dynamically create an encoded command from that information. 
     In one or more embodiments, the image determiner  110  in the processing device  102  may also include a command encryptor  210 . The command encryptor  210  may encrypt the command so that a printing device cannot execute the command unless the command is first decrypted. This may be to prevent unauthorized persons from controlling the printing device, or to prevent an unauthorized printing device from executing the command. The encryption may occur before or after a command is determined by the command generator. The encryption may also occur instead of, or in addition to, the encoding of the command by the command encoder. 
     The command encryptor  210  may include hardware, firmware, or a software application configured to encrypt a command. The command encryptor may also include memory and a processor. For example, the command encryptor  210  may include a set of program instructions stored on a memory that, when executed by a processor, causes a command to be encrypted. Any method of encryption may be used by the command encryptor, such as hashing encryption, symmetric key encryption, or asymmetric key encryption, for example. 
     The image determiner  110  in the processing device  102  may also include an image generator  212 . The image generator  212  may generate an image from the command generated or selected by the command generator  206 . In some embodiments, the image generator may generate an image from an encoded and/or encrypted command. In other embodiments, the image generator may select an image from a pre-determined set of images corresponding to commands for a printing device. 
     The image generator  212  may include hardware, firmware, or a software application configured to generate an image. The image generator  212  may also include memory and a processor. For example, the image generator  212  may include a set of program instructions stored on a memory that, when executed by a processor, causes an image to be generated based on a command. The generated image may be a barcode or QR code image, for example.  FIG. 2  shows, as an example, a QR code rendered on the portable medium  130 . The generated image may be of any form such that it corresponds to a command for controlling a printing device. 
     As described above with reference to  FIG. 1 , the image renderer  120  may render an image  132  onto a portable medium  130 . The image renderer  120  may comprise a set of instructions on a computer-readable medium that, when executed, causes the image  132  to be displayed on a display screen of an electronic device. In some embodiments, one or more components of the processing device  102  may be integrated with the portable medium  130 . For example a portable electronic device such as a smart phone or tablet computer may include the display screen (on which the image  132  may be rendered), as well as instructions configured to carry out the acts described above in reference to the processing device  102 . 
     The system  200  may also include a printing device  140 . The printing device  140  may include some or all of the components discussed above in connection with the printing device  140  in  FIG. 1 . In addition, the printing device  140  may also include a command decoder  244  and/or a command decryptor  246 . 
     The command decoder  244  may decode the encoded command corresponding to the image read into the printing device. The command decoder  244  may include hardware, firmware, or a software application configured to decode a command. The command decoder  244  may also include memory and a processor. The command decoder  244  may include a set of program instructions stored on a memory that, when executed by a processor, causes a command to be decoded. For example, the command decoder  244  may convert the image  132  received by the printing device into an alphanumeric format. The command decoder  244  may convert a bar code image that includes various vertical lines into an alphanumeric format using the spacing and thickness of the lines. In another example, the command decoder  244  may convert a QR code image into an alphanumeric format by using the spacing and size of the dots contained in the QR code image. 
     In some embodiments, the command decoder  244  may decode the command contained in the image  132  by parsing the command into its components, namely the command code, command type, check sum, and associated data, for example. This may allow the printing device to perform further operations, such as decryption and/or execution. 
     The printing device  140  may also include a command decryptor  246 , which may decrypt the command. The command decryptor  246  may include hardware, firmware, or a software application configured to decrypt a command. The command decryptor  246  may also include memory and a processor. The command decryptor  246  may include a set of program instructions stored on a memory that, when executed by a processor, causes a command to be decrypted. The set of instructions may cause an encrypted command to be converted to a decrypted form by applying a decryption algorithm, which may depend upon the method of encryption used by the processing device. For example, the command decryptor  246  may use a decryption key, which may be the same key used for encryption (symmetric key encryption) or a different key (asymmetric key encryption). Other types of decryption are possible. 
     III. Method Examples 
       FIGS. 3-5  are flowcharts illustrating example methods for controlling a printing device. The methods include blocks that may be carried out in an order different from the order shown. In addition, various steps may be added to or removed from the described methods without departing from the intended scope of this disclosure. The methods may correspond to steps that may be carried out using some or all of the elements of the systems  100  and  200 , as illustrated in and described with reference to  FIGS. 1 and 2 . 
       FIG. 3  is a flowchart illustrating a method  300  for controlling a printing device according to an example embodiment. Step  310  includes determining an image corresponding to a command for controlling a printing device. This step may include determining an image corresponding to a command for controlling a printing device, wherein the command is for performing maintenance on the printing device. In some embodiments, this step may entail dynamically creating a command for performing maintenance on a printing device. As an example, a command to print out a specific report may require a report number, chosen by a user, to be included with the command. As such, step  310  may include receiving the chosen report number, and then dynamically generating a command which includes the chosen report number. Alternatively, step  310  may include choosing a command from a list of predetermined commands. Step  310  may further include generating or selecting an image corresponding to the generated or chosen command. 
     Step  320  includes rendering the image on a portable medium. For example, step  320  may include printing an image corresponding to a command on a portable medium such as paper, cardstock, or other similar medium. Alternatively, step  320  may include displaying the image corresponding to a command on the screen of a portable electronic device such as a smartphone, tablet computer, or other electronic medium. 
     Step  330  includes reading the image into a printing device. In one embodiment, this step may be performed by a scanner. The scanner may be a component of the printing device, for example as one function of an MFP device. Alternatively, step  330  may be performed by a stand-alone scanner, digital camera, barcode scanner, or other electronic device that can read an image. These example devices may be connected to the printing device via a wired or wireless data link or communication network. 
     Step  340  includes determining if a command is contained in the image. In one embodiment, step  340  may include comparing the image read into the printing device to a set of pre-determined images. In another embodiment, step  340  may include converting the image into an alphanumeric form. The step may then include comparing the alphanumeric command to a list of predetermined commands to determine if a match is present. In another embodiment, step  340  may include determining that a command is contained in the image based on the content of the image or placement of the image on the portable medium. For example, the printing device may determine that a command is present each time a barcode or QR code is read into the device. 
     Step  350  includes executing the command. The command may be for performing maintenance on a printing device, which may include causing a printing device to restart, clear memory, print out a status report, or set sleep mode. Many other commands are possible. 
       FIG. 4  is a flowchart illustrating a method  400  for controlling a printing device according to an embodiment that includes encoding and decoding a command. The method  400  may be similar or identical to the method  300  in some respects. The method  400  includes additional steps  302  and  342 , which correspond to encoding and decoding the command respectively. Step  302  includes encoding a command into alphanumeric format. As discussed previously, the command for controlling a printing device may include causing a printing device to restart, clear memory, print out a status report, or set sleep mode, for example. Each of these commands may be encoded into an alphanumeric format, such that each command has a unique code. For example, each command may be encoded as a number between 0 and 255. In addition, command type, check sum, any associated data and/or relevant information may be encoded as well. 
     Step  342  includes decoding the command. The printing device may decode the command from an alphanumeric format into a different format. For example, if the command encoded in the image is a number between 0 and 255, the step  342  of decoding the command may include converting the number into something meaningful to the printing device, such as bit patterns corresponding to ‘restart device,’ ‘clear memory,’ ‘print out a status report,’ or ‘set sleep mode.’ 
       FIG. 5  is a flowchart illustrating a method  500  for controlling a printing device according to an embodiment that includes encrypting and decrypting a command. The method  500  may be similar or identical to the method  300  in some respects. The method  500  includes additional steps  304  and  344 , which correspond to encrypting and decrypting the command respectively. Step  304  includes encrypting the command. In at least one embodiment, the command may be encrypted before an image is rendered. The encryption may be hashing encryption, symmetric key encryption, or asymmetric key encryption, for example. This step may be done to prevent unauthorized persons from controlling the printing device, or to prevent an unauthorized printing device from executing the command. The method  500  may also include decrypting the command as shown in step  344 . 
     IV. Other Examples 
       FIG. 6  is a schematic diagram illustrating the printer device control method according to an embodiment. In one embodiment, a server  602  creates, selects, or otherwise generates a command. The command may be chosen by a user through the use of a user interface, such as a keyboard and/or mouse. Alternatively, the command may be created, selected, or generated based on input from a device connected to the server  602  via a wired or wireless network interface. This may allow the server to receive input from a remote device, such as a PC or tablet computer, for example. In one embodiment, server  602  may contain a list of commands that may control a variety of printing device models and versions. As such, the server  602  may allow a person performing maintenance on a remotely located printing device to request a command specific to a given device from a central server even though he or she is not physically present at the server location. In addition, it may allow a person unfamiliar with the specific printing device at issue to be able to control and perform maintenance by using a command created, selected, or generated by the server. 
     The server  602  may be any type of computer server or computing device, and may be connected to a printer  604  via a wired or wireless connection such as Ethernet, Universal Serial Bus (USB), RS-232, Wi-Fi, local area network (LAN), wide area network (WAN), or any other method of connection. The server  602  may process the command by encoding or encrypting the command as described in connection with  FIG. 2 . The printer  604  may receive the image from the server  602 , and then may render the image  132  onto the portable medium  130  by printing the image onto paper, for example. 
     The printing device  140  may then read the image  132  in a manner the same as or similar to that described in connection with  FIGS. 1 and 2 . The printing device may optionally decode and/or decrypt the command contained in the image. The printing device may then execute the command. 
       FIG. 7  is a schematic diagram illustrating the printer device control method according to an embodiment. The method of  FIG. 7  may be similar or identical in some respects to the method shown in  FIG. 6 . In one embodiment, the server  602  creates, selects, or otherwise generates a command. The creation, selection, or generation of the command may be in a manner similar to or the same as that described above in connection with  FIG. 6 . The server  602  may communicate with a portable medium  130  via a wired or wireless communication network. The portable medium  130  may be a portable electronic device with a display. The server  602  may create, select, or generate an image  132  corresponding to a command, and send the image over the communication network to the portable electronic device  130 . The portable electronic device may then display the image  132  on its display screen. In one embodiment, the portable electronic device may include an application or set of computer-readable instructions that, when executed by a processor on the portable electronic device, causes the portable electronic device to perform the actions of the server  602 . In other words, the server  602  and portable medium  130  may be embodied within a single (unitary) portable electronic device. The application or instructions may determine a command and generate or select an image corresponding to the command. The portable electronic device may then display the image on its display screen. 
     Printing device  140  may then read in the image displayed on the display screen of the portable electronic device by scanning the display screen. In some embodiments, the scanner may be a component of the printing device; for example, as one function of an MFP device. Alternatively, the scanner may take the form of a device physically separate from the printing device. Printing device  140  may then execute the command corresponding to the image  132 . 
       FIG. 8  is a schematic diagram illustrating the image generating and rendering according to an example embodiment. In at least one embodiment, an image determiner  110  includes a command list  802 . The command list  802  contains a list of commands  804  for controlling a printing device. Specifically, the commands may be for performing maintenance on a printing device, and may include causing a printing device to restart, clear memory, print out a status report, or set the device in or out of sleep mode. In some embodiments, there may be data  806  associated with the commands  804 . The data may be a status report number, a value indicating whether sleep mode should be on or off, a value of a setting to be modified, network communication information, or any other data related to maintenance of a printing device. 
     The method  800  may include encoding the command into an alphanumeric format. For example, an encoded command may include a command type  810 , a command code  812 , data  806 , and a check sum  814 . The command type  810  may be a representation of the type of command to be performed by the printing device. The type of command may indicate whether any data  806  is associated with the command. For example, ‘restart device’ may not require any data, and the encoded command may have a command type of ‘01’ to indicate no data is included. However, setting ‘sleep mode’ may require additional data to indicate whether sleep mode should be on or off, in which case the encoded command may have a command type value of ‘10’ to indicate that associated data is included. 
     The command code  812  may include an alphanumeric value that indicates the command to be performed by the printing device. The command code may be a value between 0 and 255. For example, the command code for restart device may be ‘11.’ The method  800  may also include encoding a check sum  814 . The check sum may include a value used for error detection and/or correction in the event a value is incorrectly transmitted to the printing device or some other error occurs. 
     The method  800  may also include converting the command from an alphanumeric form to an image form, such as a QR code or barcode. Any image that corresponds to the encoded command may be used. The image may then be printed or displayed on a portable medium  130 . 
     While various examples and embodiments have been disclosed, other examples and embodiments will be apparent to those skilled in the art. The various disclosed examples and embodiments are for purposes of illustration and are not intended to be limiting, with the true scope indicated by the following claims.