Replaceable printer component including a memory storing a tag encryption mask

[0001] Modern printing systems typically include one or more replaceable printer components, such as ink cartridges, inkjet printhead systems, toner cartridges, ink supply systems, etc. In some existing systems, these interchangeable printer components are provided with built-in memory for for sending removable item information to the printer, such as ink level, commercial information, etc.

[0002] Some of the information stored in the built-in memory may be reserved to the manufacturer of the replaceable printer component. Information stored in the built-in memory should be protected from being viewed or unauthorized changes. In addition, for some information stored in the built-in memory, protecting it from being previewed by any listening device when passing it between the built-in memory and the host may be useful. In addition, the encrypted information and the location of the encrypted information in the built-in memory may change with the lifetime of the printer in which the replaceable printer element is used.

[0003] For this and other reasons, there is a need for the present invention.

[0004] GB 2,354,735 A describes an interchangeable element of a printing device, such as a toner cartridge, which is equipped with a radio frequency identification (RFID) memory label with password protected data areas to control read and write access to memory labels. The printing device is equipped with an interrogator that emits a radio frequency field that provides power to the memory label by means of an antenna coil. The memory label provides an encrypted authorization code that, if found correct by the printing device, enables all printing functions of the printing device. The memory label uses encryption methods to allow read or write access to selected areas of the memory label only to authorized users.

[0005] US 2002/0122671 explains that encrypted data and unencrypted data are stored in a distinguishable form in the memory of a process cartridge connected to an electrophotographic printer in a detachable manner.

Summary of the Invention [0006] The object of the present invention is to provide an improved replaceable printer element, enabling the printing system to handle different locations of encrypted data in the memory of that element.

[0007] This object is achieved by means of an interchangeable printer element described in claim 1.

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Brief Description of the Drawings [0008] The attached figures serve to better understand embodiments of the invention, and have been incorporated into and are part of the present specification. The figures illustrate the embodiments of the invention and together with the description serve to explain the principles of the embodiments. Other exemplary embodiments and many of the intended benefits of the exemplary embodiments will become apparent when they are better understood by reading the following detailed description. The elements in the figures of the drawings are not always represented in appropriate mutual proportions. Similar reference numbers designate similar parts.

Figure 1 is a block diagram showing one embodiment of a printing system.

Figure 2 is a table illustrating one embodiment of the format of the information stored in the memory device of the removable printer element.

Figure 3 is a flowchart illustrating one embodiment of a method of using a removable device storage device of the printer.

Detailed description of the invention [0009] In the following detailed description, reference is made to the accompanying drawings, which form part thereof, and illustrate specific embodiments in which the invention can be practically used. In this connection, direction terms such as "up", "down", "front", "back", "leader", "end" etc. are used to refer to the orientation of the figures described. Since the components of the embodiments of the invention may be located in a wide variety of orientations, the direction terms are used for illustrative purposes and are in no way limiting. It should be understood that other embodiments may be used, and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is therefore not intended to be construed in a limiting sense, and the scope of the present invention is defined by the appended claims.

[0010] It should be understood that the features of the various embodiments of the invention described herein can be combined with each other, unless explicitly stated otherwise.

[0011] Figure 1 is a block diagram illustrating one embodiment of the printing system 100. Printing system 100 includes host 102 and printing system 104. The printing system 104 facilitates printing graphic and / or text images on a print medium 118, such as paper, cardboard, transparent film, Mylar, fabric and the like. The printing system 104 includes, for example, an inkjet printer, laser printer or other suitable printer. Host 102 communicates with the printing system 104 and sends data and / or control signals to the printing system 104. Host 102 can reside in many sources of information, such as a computer, hardware, or other appropriate device, such as digital personal assistant (PDA), digital camera, mobile phone, etc.

[0012] In one embodiment, the printing system 104 includes a printer driver 116 and a replaceable printer element 108. The replaceable printer element 108 includes a memory device 110. In one embodiment, the memory device 110 stores the tag encryption mask 111

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EP 2 286 328 B3 in the header memory area. The tags defining the data and the data defined by these tags are stored in memory device 110 in the memory data area. The data defined by each tag can be either encrypted or unencrypted. The tag encryption mask 111 indicates the encryption status of the data defined by each tag stored in the storage device 110, indicating whether the data is encrypted or unencrypted.

[0013] The printer controller 116 controls the operation of the printing system 104 and, as such, receives data and / or control signals from the host 102. The printer controller 116 communicates with the host 102 via communication link 106. Communication link 106 includes, for example, electrical , optical, infrared based or other appropriate path for transferring information between the printer driver 116 and the host 102.

[0014] The replaceable printer element 108 includes a printing system element 104 that can be inserted into and removed from the printing system 104. In one embodiment, the replaceable element of the printer 108 includes a consumable element that is removed and replaced when its useful life has expired. One example of such a consumable item may be an ink cartridge or toner cartridge that contains a supply of marking material for the printing system 104. The marking material is thrown onto the print media 118 through the printing system 104 and is depleted during the life of the ink cartridge or toner cartridge. In this sense, the ink cartridge or toner cartridge is discarded and replaced when its shelf life has expired or is refilled and used again.

[0015] In another embodiment, the replaceable printer element 108 includes a printing element that is easily replaceable in the printing system 104. Examples of such printing elements include a printhead that selectively places ink on print media 118 in response to control signals from the printer controller 116 or print cartridges consisting of the printhead and the ink supply system. Thus, the replaceable printer element 108 may include an ink cartridge, printhead or printer cartridge if, for example, the printing system 104 includes an inkjet printer. Furthermore, the replaceable printing element 108 may include a toner cartridge or developer drum if, for example, the printing system 104 includes a laser printer. Furthermore, the replaceable printer element 108 may include a peripheral device of the printing system 104, such as an Ethernet card, duplex, paper finisher (e.g. stapler, punch etc.) or other suitable device.

[0016] The printer driver 116 and the replaceable printer element 108 communicate with each other via communication link 114. Communication link 114 facilitates the transfer of information between the printer driver 116 and the replaceable printer component 108 when the replaceable printer component 108 is installed in the printing system 104. The communication link 114 includes, for example, an electrical, optical, infrared based or other suitable path for transferring information between the replaceable printer element 108 and the printer driver 116.

[0017] The replaceable printer element 108 includes a memory device 110 that stores information for the replaceable printer element 108 and / or the printing system 104. In one embodiment, memory device 110 includes non-volatile 256-bit memory or other suitable capacity, such as EEPROM, FLASH or other suitable type of memory. In one embodiment, memory device 110 stores, for example, information that relates to a specific replaceable printer element 108 or information that applies to printing system 104. In addition, memory device 110 may contain stored information for use by

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The printing system 104 or may record information for the printing system 104. In one embodiment, the information that may be stored in the memory device 110 includes operational or non-operational parameters for the replaceable printer element 108 and / or the printing system 104.

[0018] In one embodiment, the replaceable printer element 108 includes a communication link 112 that electrically or communicationly connects the memory device 110 to the communication link 114, and thus, to the printer controller 116 when the replaceable printer element 108 is installed in the printing system 104. In this sense, when the replaceable printer element 108 is installed in the printing system 104, the memory device 110 communicates with the printer driver 116 via communication links 112 and 114. Thus, communication links 112 and 114 include, for example, electrical connectors or connections, such as electrical contacts or plugs, which connect to their respective electrical nodes or sockets, respectively.

[0019] The printer driver 116 includes an encryption / decryption circuit, logic circuit or encryption / decryption algorithm 117. When the replaceable printer element 108 is installed in the printing system 104, the printer driver 116 reads the information stored in the memory device 110, including the label coding mask 111, labels and the data defined by these labels. The encryption / decryption algorithm 117 then decrypts the data defined by each label, the label encryption mask 111 indicating that the data defined by the label is encrypted. Therefore, some blocks of data stored in memory device 110 may be encrypted, while other blocks of data stored in memory device 110 may remain unencrypted. When the printer driver 116 writes data to memory device 110, the encryption / decryption algorithm 117 first encrypts the data defined by each label, the label encryption mask 111 indicating that the data defined by the label is encrypted. The encrypted data is then saved to memory device 110.

[0020] The encryption mask of the label 111 allows encryption of any selected parts or blocks of the memory device 110 by the manufacturer or by another authorized user of the replaceable printer element 108 without first programming the printing system 104 to recognize that some parts or blocks of the memory device 110 store encrypted data. Thus, the encrypted data and the location of the encrypted data stored in the memory device 110 of the replaceable printer element 108 may change over the life of the printing system 104. [0021] Figure 2 is a table illustrating one embodiment of the format 150 of information stored in the memory device 110 of the replaceable printer element 108. Storage device 110 includes a header area indicated by 152 and a data area indicated by 154. Header area 152 begins at address 0 and ends with address "A-1", where "A" is an integer that specifies the number of bytes of storage device 110. In one embodiment, header area 152 is not encrypted. Header area 152 contains label encryption mask 111. In one embodiment, the label encryption mask 111 occupies 2 bytes (16 bits) in memory device 110.

[0022] In one embodiment, data area 154 includes 16 parts or blocks in memory device 110. In other embodiments, data area 154 includes less than 16 parts or blocks. Each of the 16 blocks contains a label marked "T0" to "T15" and label information. For each block, the label is stored in memory device 110 immediately before

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EP 2 286 328 B3 with label data. In one embodiment, the labels are not encrypted. Each label defines the identity of the label and the length of the label data. The label identity identifies the type of data stored in the next block of storage device 110. The address range for the block is determined based on the length of the label data. The address range for each block is defined in the range from "A" to "Q", where the letters "A" and "Q" are integers that specify the number of bytes of memory device 110. For example, the label "T0" defines the type of data stored in the address range from "A + 1" to "B-1". The label "T1" defines the type of data stored in the address range from "B + 1" to "C1". Similarly, the label "T15" defines the type of data stored in the address range from "P + 1" to "Q1". Labels can be stored in data area 154 in any order. In addition, the contained label identities do not have to form a continuous range. For example, in one embodiment, data area 154 includes six data storage blocks defined by the following labels in the order given: "T3", "T1", "T4", "T5", "T6" and "T10". The data type and data length defined by each label can be different for each label from "T0" to "T15". For example, the "T0" label data length can be 12 bytes, the "T1" label data length can be 32 bytes, the "T2" label data length can be 44 bytes, etc.

[0023] Each respective bit of the label encryption mask 111 indicates whether the label data defined by each corresponding label is encrypted or unencrypted. The first bit of the encryption mask of label 111 indicates whether the data defined by the label "T0" is encrypted or unencrypted. The second bit of the encryption mask of the label 111 indicates whether the data defined by the label "T1" is encrypted or unencrypted. Similarly, the 16th bit of the label encryption mask 111 indicates whether the data defined by the label "T15" is encrypted or unencrypted.

[0024] In one embodiment, the bit with a logical "0" in the encryption mask of the label 111 indicates that the data defined by the corresponding label is not encrypted and the bit with the logical "1" in the encryption mask of the label 111 indicates that the data defined by the corresponding them label are encrypted. In another embodiment, the bit with a logical "1" in the encryption mask of the label 111 indicates that the data defined by the corresponding label is not encrypted and the bit with the logical "0" in the encryption mask of the label 111 indicates that the data defined by the corresponding label is encrypted. For example, in one embodiment, where logical "1" means encrypted data, the label encryption mask in the form "0010-0000-0100-0001" indicates that the data defined by the labels "T13", "T6" and "T0" are encrypted and the data defined by the other labels are not encrypted. Other embodiments use a different number of labels and a correspondingly different label encryption mask length 111, such as 32 labels and a 32-bit label encryption mask, respectively.

[0025] Figure 3 is a flowchart illustrating one embodiment of a method 200 of using the memory device 110 of the replaceable printer element 108. At step 202, the labels and data associated with each label are defined. Each label defines the type of data to be stored behind the label and the length of the data. At step 204, data to be encrypted in the storage device 110 of the replaceable printer element 108 is identified. At step 206, the identified data is encrypted and the labels and data defined by these labels are stored in the data area of ​​memory device 110. At step 208, an encryption mask is recorded in the header area of ​​the storage device 110 indicating which data is encrypted and which data is unencrypted. In one embodiment, the above process described in blocks 202 to 208

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EP 2 286 328 B3 inclusive, is made by the manufacturer of the replaceable printer element 108 in the production process of the replaceable printer element 108.

[0026] At step 210, the user installs the replaceable printer element 108 in the printing system 104. When the replaceable printer component 108 is installed in the printing system 104, the printer driver 116 communicates with the memory device 108 via communication links 112 and 114. At step 212, the printer driver 116 reads the memory device 110 containing the label encryption mask and labels and the data defined by these labels. At step 214, the encryption / decryption algorithm 117 of the printer driver 116 decrypts any encrypted data read from memory device 110 as indicated by the label encryption mask. When the printer driver 116 writes data to the memory device 110, the encryption / decryption algorithm 117 first encrypts any data to be saved in the encrypted area of ​​the memory device 110 according to the label encryption mask.

[0027] Embodiments provide a replaceable printer element comprising a memory device. The storage device implementations store a label encryption mask that indicates which parts of the storage device store encrypted data and which parts of the storage device store unencrypted data. The printing system in which the implementation of the replaceable printer element is installed decrypts the encrypted data during the read operation based on the label encryption mask. In addition, the printing system in which the implementation of the replaceable printer element is installed encrypts data during the write operation, based on the label encryption mask. Therefore, in the embodiments, the encrypted data and the location of the encrypted data stored in the memory device of the removable printer element may change over the life of the printing system.

[0028] Although specific embodiments are described and described herein, one of ordinary skill in the art will appreciate that certain embodiments illustrated and described herein can be replaced by many alternative or equivalent embodiments without departing from the scope of the present invention. The purpose of this application is to cover any adaptations and variants of certain embodiments described herein. The present invention is limited only by the appended claims.

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EP 2 286 328 B3