JP2003320658A - Ink cartridge judging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately make a decision whether an ink cartridge is a previously registered product or not. <P>SOLUTION: An encrypting section 124 encrypts the serial number ID of an ink cartridge 200 using a first private key Ka to generate a bit matrix BM. A logical operating section 126 calculates XOR of first extra information A1 and the bit matrix BM to obtain a random number RND. The encrypting section 124 encrypts the random number RND using a second private key Kb to create a digital signature SIG'. The logical operating section 126 calculates XOR of second extra information A2 and the bit matrix BM to obtain a digital signature SIG. A comparing section 128 compares the digital signature SIG thus obtained with the generated digital signature SIG' and makes a decision that a mounted ink cartridge 200 is a registered product if the digital signatures SIG and SIG' coincide with each other otherwise makes a decision that the mounted ink cartridge is not a registered product. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for determining whether or not an ink cartridge mounted on a printer is a product registered in advance.

[0002]

2. Description of the Related Art Generally, a printer driver for driving a printer is a manufacturer who manufactures the printer or a related company thereof (hereinafter referred to as a printer manufacturer).
The printer is designed so that the most appropriate printing can be performed when printing is performed by the printer using the ink cartridge manufactured by the printer manufacturer or the like.

[0003]

However, when printing is performed by the printer using an ink cartridge manufactured by a so-called third party other than the printer manufacturer, the ink stored in the ink cartridge is The characteristics may differ from the original ones, and optimum printing may not be possible.

Therefore, when the ink cartridge is attached to the printer, it is properly determined whether or not the ink cartridge is a product registered in advance by a printer manufacturer or the like. If any notification is given to the user, the convenience for the user is also improved.

Therefore, an object of the present invention is to provide a technique for solving the above-mentioned problems of the prior art and appropriately determining whether or not the product is a product registered in advance as an ink cartridge for the printer. is there.

[0006]

In order to achieve at least a part of the above-mentioned object, the ink cartridge determination device of the present invention determines whether the mounted ink cartridge is a registered product. An ink cartridge determination device for determining whether or not it is based on information recorded in a recording unit of the ink cartridge, wherein a secret key storage unit for storing first and second secret keys and a recording unit Of the recorded information, at least a reading section for reading the identification code of the ink cartridge and the first and second additional information, and the read identification code are stored in the secret key storage section. The first secret key that is used to generate the first encrypted information
An encryption unit, and a first logical operation unit that obtains a first logical operation value by calculating an exclusive OR of the read first additional information and the generated first encrypted information. A second logical operation unit that calculates an exclusive logical sum of the read second additional information and the generated first encrypted information to obtain a second logical operation value; A second encryption unit for encrypting the first logical operation value with the second secret key stored in the secret key storage unit to generate second encrypted information;
A comparison determination unit that compares the acquired second logical operation value with the generated second encrypted information and determines whether the ink cartridge is a registered product based on the comparison result. It is a gist to have ,.

In the ink cartridge determination device of the present invention, the first additional information recorded in the recording portion of the ink cartridge is generated by, for example, encrypting the identification information of the ink cartridge with the first secret key. The second additional information is obtained by calculating the exclusive OR of the encryption information and the random number, and the second additional information is generated by encrypting the random number with the second secret key. And the first above
If it is obtained by calculating the exclusive OR of the encrypted information and the encrypted information, the first logical operation value obtained by the first logical operation unit is the above-mentioned random number. The information generated by encrypting the random number with the second secret key in the encryption unit is exactly the second encrypted information. on the other hand,
The second logical operation value obtained by calculating the exclusive OR of the second additional information and the first encrypted information in the second logical operation unit also becomes the second encrypted information.

Therefore, if the first and second additional information recorded in the recording unit of the ink cartridge is the above-mentioned information, the second logical operation value and the second logical operation value acquired by the second logical operation unit are obtained. Since the second encryption information matches the second encryption information generated by the encryption unit, the comparison determination unit determines that the mounted ink cartridge is a registered product. But,
If the information is not the above information, it is determined that the product is not a registered product.

Therefore, according to the ink cartridge determination apparatus of the present invention, it is possible to properly determine whether or not the ink cartridge is a registered product based on the information recorded in the recording section of the ink cartridge. You can

In the ink cartridge determination apparatus of the present invention, the secret key storage section stores a plurality of the first and second secret keys corresponding to the manufacturing time of the ink cartridge, and the reading section stores the recording. Further, information of the manufacturing time of the ink cartridge is read out from the information recorded in the section, and further, based on the read information of the manufacturing time, the secret key storage section is used to detect the manufacturing time. It is preferable to include a search unit for searching the corresponding first and second secret keys.

As described above, by preparing a plurality of first and second secret keys corresponding to the manufacturing time of the ink cartridge, it becomes difficult to illegally use these secret keys.

In the ink cartridge determination device of the present invention, the reading section further reads information on the ink remaining amount of the ink cartridge among the information recorded in the recording section, and the ink mounted in the past. An ink cartridge information storage unit that stores the identification code of the cartridge and the ink remaining amount of the ink cartridge in association with each other, and the read identification code is the identification code of the ink cartridge installed in the past. If it is stored in the ink cartridge information storage,
An ink remaining amount derivation unit that derives a corresponding ink remaining amount from the ink cartridge information storage unit, wherein the comparison determination unit includes the in-remaining amount derived by the ink remaining amount derivation unit and the read-out. It is preferable to compare the remaining ink amount read by the unit and determine whether or not the ink cartridge is a registered product based on the comparison result.

Even if the installed ink cartridge is an ink cartridge in which used ink is illegally replenished and the ink remaining amount recorded in the recording section is rewritten, By comparing the remaining ink amounts with each other, it can be determined that the ink cartridge is an unauthorized one, and it can be determined that the product is not a registered product.

The ink cartridge of the present invention is an ink cartridge to be installed in a printer, and has a recording section for recording identification information indicating that it is a registered product, and the identification information is the same as that of the ink cartridge. The identification code, the first encryption information generated by encrypting the identification information with the first secret key, and the first additional information obtained by calculating the exclusive OR of the random number and the random number. And second additional information obtained by calculating an exclusive OR of the second encrypted information generated by encryption with the second secret key and the generated first encrypted information. Is the gist.

By recording the above information as identification information in the recording portion of the ink cartridge,
The ink cartridge determination device can determine that the product is a registered product.

In the ink cartridge of the present invention, it is preferable that the identification information further includes information on a manufacturing time of the ink cartridge.

By including the manufacturing time information in this manner, for example, when a plurality of first and second secret keys are prepared corresponding to the manufacturing time in the ink cartridge determination device, the manufacturing time is reduced. Based on the timing information,
It is possible to retrieve the first and second secret keys corresponding to the manufacturing time.

The present invention is not limited to the above-described aspects of the device invention such as the ink cartridge determination device and the ink cartridge, but may be implemented as a method invention such as an ink cartridge determination method.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in the following order based on Examples. A. First Example: A-1. Configuration of First Embodiment: A-2. Ink cartridge determination process: B. Second Example: B-1. Configuration of Second Embodiment: B-2. Ink cartridge determination process: C.I. Modification:

A. First Example: A-1. Configuration of First Embodiment: FIG. 1 is a block diagram showing a printer 100 including an ink cartridge determination device according to a first embodiment of the present invention.

The printer 100 shown in FIG. 1 exchanges data and the like between a CPU 110 for controlling printing according to a program, a memory 120 for storing the program, and various peripheral components. I
/ O section 130, operation panel 140 for inputting instructions from the user, display panel 150 for notifying the user of the status and notification, and secret for storing secret key information 162 for ink cartridge determination. Key storage 1
60, a mounting portion 170 to which the ink cartridge 200 is mounted, and an IC 20 provided in the ink cartridge 200
2 IC information access unit 180 for reading information
And are equipped with. In addition, although not shown, the printer 100 uses the ink cartridge 2 for printing paper.
It is provided with a mechanism section for relatively moving the mounting section 170 mounted with No. 00 and for conveying the printing paper.

Of these, the CPU 110 has a memory 120.
By reading and executing the above-mentioned program stored in the search unit 122, the encryption unit 124, the logical operation unit 1
26 and the comparison determination unit 128. The ink cartridge determination apparatus according to the present exemplary embodiment is mainly configured by the search unit 122, the encryption unit 124, the logical operation unit 126, the comparison determination unit 128, and the IC information access unit 180, which function as the CPU 110.

On the other hand, the ink cartridge 200 is a product manufactured by a printer manufacturer or the like and has at least an IC 202, and the IC 202 has
Identification information 204 indicating that the product is registered by the printer manufacturer or the like is recorded.

FIG. 2 shows the IC2 of the ink cartridge 200.
2 is an explanatory diagram showing identification information 204 recorded in 02 and a method of generating the identification information 204. FIG.

When a printer manufacturer or the like manufactures the ink cartridge 200, as the identification information 204 in the IC 202, as shown in FIG. Date Date, serial number ID of ink cartridge 200, first additional information A1, second additional information A2
And, respectively.

These pieces of information are generated by a printer manufacturer or the like as follows. That is, as shown in FIG. 2, first, in addition to the manufacturing date Date, the manufacturing number ID, and the first secret key Ka of the ink cartridge 200.
A second secret key Kb and a random number RND are prepared. Among them, as the first secret key Ka, the same value is prepared for the products manufactured in the same manufacturing month. Then, the value is switched every manufacturing month. The same applies to the second secret key Kb. Further, with respect to the manufacturing number ID and the random number RND, different values are prepared for each product. The first secret key Ka and the second secret key Kb may have the same value.

Next, the serial number ID is encrypted with the first secret key Ka to generate the bit mask BM, and the exclusive OR (XOR) of the bit mask BM and the random number RND is calculated to make the first addition. Obtain information A1. On the other hand, the random number RND is encrypted with the second secret key Kb to generate the electronic signature SIG,
The XOR of the electronic signature SIG and the bit mask BM is calculated to obtain the second additional information A2. Note that the encryption algorithm used may be the same for the encryption using the first secret key Ka and the encryption using the second secret key Kb, but if the cost is acceptable, another encryption algorithm is used. It is better to use an algorithm.

The information thus obtained is recorded in the IC 202 as the identification information 204.

Further, as shown in FIG. 1, on the outer surface of the ink cartridge 200, a contact 206 for electrical connection is provided for exchanging information with the outside. On the other hand, a similar contact 172 is also provided on the mounting surface of the mounting portion 170 of the printer 100. Therefore, the ink cartridge 200 is installed in the mounting portion 170 of the printer 100.
The contact 206 of the ink cartridge 200 is joined to the contact 172 of the mounting portion 170 by mounting
IC 202 of ink cartridge 200 and printer 10
The IC information access unit 180 of No. 0 is electrically connected.

On the other hand, the private key storage unit 1 of the printer 100
In 60, secret key information 1 for ink cartridge determination
As shown in FIG. 3, as 62, a first secret key Ka and a second secret key Kb prepared when manufacturing the ink cartridge are stored.

FIG. 3 shows the private key storage unit 1 of the printer 100.
6 is an explanatory diagram showing an example of secret key information 162 stored in 60. FIG. As described above, since different values are prepared for the first secret key Ka and the second secret key Kb for each manufacturing year, the secret key information 162 is as shown in FIG.
As shown in, the first secret key Ka is divided by manufacturing year and month.
And the second secret key Kb are stored.

Incidentally, in FIG. 1, the encryption unit 124 is
In the first and second encryption units of the present invention, the logical operation unit 126 is included in the first and second logical operation units, and the comparison determination unit 1 is included.
28 is a comparison determination unit, and the search unit 122 is a search unit.
The C information access unit 180 uses the reading unit as the IC 202.
Corresponds to the recording unit, respectively.

A-2. Ink Cartridge Determination Process: Now, the ink cartridge determination process in the printer 100 of the present embodiment will be described in detail. FIG. 4 is a flowchart showing the procedure of the ink cartridge determination process in the printer 100 of FIG. 1, and FIG. 5 is a block diagram showing the ink cartridge determination process using functional blocks.

The ink cartridge determination process is executed when the printer 100 is started up or when the ink cartridge 200 is mounted while the printer 100 is operating.

When the ink cartridge determination process is started, first, the IC information access unit 1 of the printer 100 is started.
80 accesses the IC 202 of the ink cartridge 200, reads the manufacturing date Date from the identification information 204, and gives it to the search unit 122 (step S102).
The search unit 122 accesses the secret key storage unit 160,
Secret key information 16 based on the manufacturing date Date
Of the two, the first secret key Ka and the second secret key Kb corresponding to the manufacturing date are searched (step S104). For example, if the manufacturing date Date is January 25, 2002, the first secret key Ka0201 and the second secret key Kb0201 corresponding to January 2002 are searched as shown in FIG.

Next, the IC information access unit 180 makes the IC2
The production number ID is read from 02 and given to the encryption unit 124 (step S106). The encryption unit 124 uses the manufacturing number ID as the first secret key Ka obtained by the search.
And the bit mask BM is generated (step S108).

Next, the IC information access unit 180 makes the IC2
02 to read the first additional information A1 to obtain the logical operation unit 1
26 (step S110). Logical operation unit 126
Calculates the exclusive OR (XOR) of the first additional information A1 and the generated bit mask BM to acquire the random number RND (step S112). As described above, the first additional information A1 is the XO of the bit mask BM and the random number RND.
Since it is obtained by taking R, the original random number RND can be obtained by taking the XOR of the first additional information A1 and the bit mask BM.

Next, the encryption unit 124 uses the acquired random number R
The ND is encrypted with the second secret key Kb obtained by the search to generate the electronic signature SIG '(step S11).
4).

Then, the IC information access unit 180 makes the IC
The second additional information A2 is read from 202 and given to the logical operation unit 126 (step S116). Logical operation unit 12
6 calculates the XOR of the second additional information A2 and the previously generated bit mask BM to obtain the electronic signature SIG (step S118). As in the case of A1, the second additional information A2 is also obtained by taking the XOR of the electronic signature SIG and the bit mask BM, as described above, and thus the second additional information A2 and the bit mask BM are obtained. XO
By taking R, the original electronic signature SIG can be obtained.

The comparison / determination unit 128 uses the acquired digital signature S.
The IG is compared with the generated digital signature SIG '(step S120). Ink cartridge 20 installed
If 0 is the registered product, the official manufacturing date Date, the serial number ID, the first additional information A1, and the second additional information A2 should be recorded in the IC 202 as the identification information 204. Therefore, the electronic signatures SIG and SIG ′ obtained based on them should match.
However, the installed ink cartridge 20
If 0 is not a registered product, the identification information 204 recorded in the IC 202 is random, so the electronic signatures SIG and SIG ′ obtained based on them are never the same. Therefore, the comparison determination unit 128 determines that the mounted ink cartridge 200 is a registered product when the electronic signatures SIG and SIG ′ match, and when they do not match, the registration is registered. Judge that it is not a product.

When the determination result is obtained in this way, the ink cartridge determination process shown in FIG. 4 ends.

After that, the CPU 110, based on the obtained judgment result, mounts the ink cartridge 20 mounted therein.
If 0 is not a registered product, for example, the display panel 150 will display "The installed ink cartridge is not a registered product, so optimal printing may not be possible." , Get the user's attention. Alternatively, on the display panel 150,
It is also possible to display a message "Please replace with another ink cartridge because printing is not possible with the installed ink cartridge." And prompt the user to replace the ink cartridge. With this configuration, the convenience of the user who uses the printer 100 can be improved.

Further, in this embodiment, the ink cartridge 200 is not subjected to any processing, and is simply I
Since only the information recorded in C202 is read out, the configuration of the ink cartridge 200 can be simplified.

Further, in this embodiment, even if the identification information 204 is illegally read and analyzed from the IC 202 of the ink cartridge 200, it is impossible to guess the bit mask BM and the electronic signature SIG. That is, the first
The additional information A1 is BM XORRND, and the second additional information A2 is BM XOR SIG. For example, even if the XOR of both of them is calculated, the following expression (1) is obtained, and it can be estimated. Can not.

[0045] A1 XOR A2   = (BM XOR RND) XOR (BM XOR SIG)   = RND XOR SIG (1)

Further, in the present embodiment, the first and second secret keys Ka and Kb are set to different values for each manufacturing year and month, so these values are unlikely to be illegally used.

B. Second Example: B-1. Configuration of Second Embodiment: FIG. 6 is a block diagram showing a printer 100 equipped with an ink cartridge determination device according to a second embodiment of the present invention. The configuration of this embodiment is different from that of the first embodiment in that the ink cartridge 2
In addition to the identification information 204, the remaining ink amount information 208 is recorded on the IC 202 of 00, the IC information access unit 180 can write to the IC 202, and the printer 100 newly adds ink cartridge information. The point is that the storage unit 190 is provided.

Among these, as the remaining ink amount information 208, the remaining amount R ′ of the ink stored in the ink cartridge 200 is recorded.

On the other hand, the ink cartridge information storage section 19
The ink remaining amount history information 192 and the prohibited cartridge information 194 are stored in 0.

As the ink remaining amount history information 192, the ink remaining amounts of the ink cartridges installed in the printer 100 in the past are stored.

While the printer 100 is operating, the CPU 110
Calculates the number of ink droplets ejected from the ink cartridge 200 and calculates the remaining amount of ink from the number of ejections. Then, the calculated remaining ink amount is written as the remaining ink amount information 208 in the IC 202 of the ink cartridge 200 via the IC information access unit 180, and is also recorded in the remaining ink amount history information 192 of the ink cartridge information storage unit 190. Write with the number ID.
Then, the CPU 110 updates the written remaining ink amount each time the printer 100 prints. The count value may be directly written as the remaining ink amount.

FIG. 7 is an explanatory diagram showing an example of the ink remaining amount history information 192 stored in the ink cartridge information storage section 190 of the printer 100. Specifically, as the ink remaining amount history information 192, as shown in FIG. 7, the serial number I of each ink cartridge installed in the past is recorded.
D and the finally calculated remaining ink amount R are stored as a pair.

On the other hand, as the prohibited cartridge information 194, as shown in FIG. 8, the serial number ID of the prohibited ink cartridge is stored. Figure 8
Is an ink cartridge information storage unit 19 of the printer 100.
FIG. 7 is an explanatory diagram showing an example of use-prohibited cartridge information 194 stored in 0. Such prohibited cartridge information 194 includes, for example, a serial number ID grasped by a printer manufacturer or the like as a serial number ID of an ink cartridge that has been illegally used in the past.
It is written when the printer 100 is manufactured.

In FIG. 6, the search unit 122 corresponds to the ink remaining amount derivation unit of the present invention, and the ink cartridge information storage unit 190 corresponds to the ink cartridge information storage unit.

B-2. Ink Cartridge Determination Process: Now, the ink cartridge determination process in the printer 100 of the present embodiment will be described in detail. FIG. 9 is a flowchart showing the procedure of the ink cartridge determination process in the printer 100 of FIG.

Similar to the case of the first embodiment, the ink cartridge determination process is executed when the printer 100 is started up or when the ink cartridge 200 is mounted while the printer 100 is in operation.

When the ink cartridge determination process is started, first, the IC information access unit 1 of the printer 100 is started.
80 accesses the IC 202 of the ink cartridge 200, reads the serial number ID from the identification information 204, and gives it to the search unit 122 (step S202). The retrieval unit 122 accesses the ink cartridge information storage unit 190 and retrieves whether or not the read serial number ID of the prohibited ink cartridge is included in the prohibited cartridge information 194 (step). S204). When the serial number ID is included in the prohibited cartridge information 194 as a result of the search, the comparison determination unit 128 determines that the mounted ink cartridge 200 is not a registered product. On the contrary, if the manufacturing number ID is not included in the prohibited cartridge information 194, the process of the next step S206 is executed.

The search unit 122 again accesses the ink cartridge information storage unit 190, and the read manufacturing number ID is included in the ink remaining amount history information 192 as the ink cartridge that was previously mounted in the printer 100. It is searched whether or not it is present (step S206).
When the ink cartridge 200 is the first ink cartridge installed in the printer 100, the manufacturing number ID is not included in the remaining ink amount history information 192, and therefore the processing of subsequent steps S208, S210, and S212 is passed. Then, the process of step S102 shown in FIG. 1 is executed. On the other hand, the ink cartridge 200
Is it the ink cartridge that was installed until then,
Alternatively, even if the ink cartridge is newly mounted, if the ink cartridge has been mounted even once in the past, the manufacturing number ID is included in the remaining ink amount history information 192, and thus the next step S208 is executed. To be done.

The IC information access unit 180 accesses the IC 202 of the ink cartridge 200, reads out the ink remaining amount R'as the ink remaining amount information 208, and gives it to the comparison / determination unit 128 (step S208). Subsequently, the search unit 122 accesses the ink cartridge information storage unit 190 and searches the remaining ink amount history information 192 for the remaining ink amount R corresponding to the manufacturing number ID based on the manufacturing number ID. For example, if the production number ID is IDb, the ink remaining amount Rb corresponding to IDb is searched as shown in FIG. 8 (step S210).

The comparison / determination unit 128 compares the ink remaining amount R'given from the IC information access unit 180 with the ink remaining amount R obtained by the search (step S212).
As long as the ink cartridge 200 is attached to the printer 100, as described above, the ink cartridge 20
The ink remaining amount R ′ written as the ink remaining amount information 208 in the IC 202 of 0 and the ink remaining amount R written in the ink remaining amount history information 192 of the ink cartridge information storage unit 190 are the same for each printing. Should be equal, since it is updated to. Also, for example, the printer 100
When the ink cartridge 200 mounted on the printer is removed and temporarily used by another printer, and then mounted on the printer 100 again, the IC 202
The remaining ink amount R ′ written in the above table should be smaller than the remaining ink amount R written in the remaining ink amount history information 192. Therefore, the ink remaining amount R ′ written in the IC 202 is the ink remaining amount history information 1
It cannot be larger than the ink remaining amount R written in 92. However, when the ink remaining amount R ′ written in the IC 202 is illegally rewritten, the ink remaining amount R ′ written in the IC 202 is
However, it may be larger than the remaining ink amount R written in the remaining ink amount history information 192.

Therefore, as a result of the comparison, the ink remaining amount R ′ written in the IC 202 is the ink remaining amount history information 19
If the remaining ink amount R written in No. 2 is greater than the remaining ink amount R, it can be determined that the installed ink cartridge 200 is an unauthorized ink cartridge, and thus it is determined that the product is not a registered product. In this case, the comparison / determination unit 128 may newly register the manufacturing number ID in the prohibited cartridge information 194 as the manufacturing number ID of the prohibited ink cartridge.

On the other hand, when the ink remaining amount R'written in the IC 202 is less than or equal to the ink remaining amount R written in the ink remaining amount history information 192, the ink cartridge 200 is set to the proper ink. Since it can be determined that the cartridge is a cartridge, step S1 shown in FIG.
The processing of 02 is executed. Hereinafter, steps S102 to S120 shown in FIG. 1 are sequentially executed, and finally, it is determined whether or not the mounted ink cartridge 200 is a registered product.

As described above, in this embodiment, before performing the processing of steps S102 to S120 shown in FIG.
It is determined whether the mounted ink cartridge 200 is a prohibited use ink cartridge or an illegally used ink cartridge, and all the applicable ink cartridges are registered products. I try to determine that there is no.

Therefore, in the present embodiment, when the installed ink cartridge 200 is an ink cartridge in which a used product is illegally replenished with ink even if it is a registered product. I have
It cannot be used unless the ink remaining amount R ′ written in C202 is also increased. However, even if the ink remaining amount R ′ is rewritten so as to increase, as described above, the ink remaining amount R ′ written in the IC 202 is the ink remaining amount written in the ink remaining amount history information 192. Since it is larger than R, it is determined that the ink cartridge is an unauthorized ink cartridge, and it is determined that the product is not a registered product, and the user can be alerted.

C. Modification: The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the scope of the invention.

In the above-described embodiment, the ink cartridge determination device is mounted on the printer 100. However, among the components of the ink cartridge determination device, the retrieval unit 122, the encryption unit 124, the logical operation unit 126, and the All or part of the comparison / determination unit 128 may be installed in, for example, a computer connected to the printer 100. For example, when it is installed in a computer, it may be installed in a printer driver or the like.

Although the ink cartridge determination device is applied to the printer in the above-described embodiments, it may be applied to the ink cartridge recovery device for recovering the ink cartridge.

[Brief description of drawings]

FIG. 1 is a block diagram showing a printer 100 including an ink cartridge determination device according to a first embodiment of the invention.

2 is an explanatory diagram showing identification information 204 recorded in an IC 202 of the ink cartridge 200 and a method of generating the identification information 204. FIG.

FIG. 3 is an explanatory diagram showing an example of secret key information 162 stored in a secret key storage unit 160 of the printer 100.

FIG. 4 is a flowchart showing a procedure of an ink cartridge determination process in the printer 100 of FIG.

FIG. 5 is a block diagram showing an ink cartridge determination process using functional blocks.

FIG. 6 is a block diagram showing a printer 100 including an ink cartridge determination device according to a second embodiment of the invention.

7 is an explanatory diagram showing an example of ink remaining amount history information 192 stored in an ink cartridge information storage unit 190 of the printer 100. FIG.

FIG. 8 is a prohibited cartridge information 1 stored in the ink cartridge information storage unit 190 of the printer 100.
It is explanatory drawing which shows an example of 94.

9 is a flowchart showing a procedure of ink cartridge determination processing in the printer 100 of FIG.

[Explanation of symbols]

100 ... Printer 110 ... CPU 120 ... memory 122 ... Search unit 124 ... Encryption unit 126 ... Logical operation unit 128 ... Comparison determination unit 130 ... I / O section 140 ... Operation panel 150 ... Display panel 160 ... Private key storage 162 ... Secret key information 170 ... Mounting part 172 ... contact point 180 ... IC information access unit 190 ... Ink cartridge information storage section 192 ... Ink remaining amount history information 194 ... Prohibited cartridge information 200 ... Ink cartridge 204 ... Identification information 206 ... Contact 208 ... Ink remaining amount information A1 ... first additional information A2 ... Second additional information BM ... bit mask Date ... Date of manufacture ID: Serial number Ka ... the first secret key Kb ... Second secret key R ... Remaining amount of ink RND ... random numbers SIG ... electronic signature

Claims (6)

[Claims] 1. An ink cartridge determination device for determining whether or not an installed ink cartridge is a registered product based on information recorded in a recording section of the ink cartridge. A secret key storage unit for storing the first and second secret keys, and at least the information recorded in the recording unit,
A reading unit for reading the identification code of the ink cartridge and the first and second additional information, and the read identification code is encrypted with the first secret key stored in the secret key storage unit, A first encryption unit that generates one encrypted information, and an exclusive OR of the read first additional information and the generated first encrypted information is calculated to obtain a first logical operation value. A second logical operation unit that obtains a second logical operation value by calculating an exclusive OR of the first logical operation unit to be acquired and the read second additional information and the generated first encrypted information. A logical operation unit, a second encryption unit that encrypts the acquired first logical operation value with a second secret key stored in the secret key storage unit, and generates second encrypted information; Comparing the generated second logical operation value with the generated second encrypted information, Based on the comparison result, an ink cartridge determination device and a comparison determination unit determines whether the product the ink cartridge is registered. 2. The ink cartridge determination apparatus according to claim 1, wherein the secret key storage unit stores the first and second secret keys,
A plurality of ink cartridges are stored corresponding to the manufacturing time of the ink cartridges, and the reading unit further reads information on the manufacturing time of the ink cartridges from the information recorded in the recording unit, and further reads the information. Based on the information of the production time issued,
From the secret key storage unit, the first
And an ink cartridge determination device including a search unit that searches for the second secret key. 3. The ink cartridge determination device according to claim 1, wherein the reading unit further reads information on the ink remaining amount of the ink cartridge from the information recorded in the recording unit, The ink cartridge information storage unit that stores the identification code of the ink cartridge attached to the ink cartridge and the ink remaining amount of the ink cartridge in association with each other, and the read identification code of the ink cartridge installed in the past. As an identification code, when stored in the ink cartridge information storage unit, further comprises an ink remaining amount derivation unit that derives a corresponding ink remaining amount from the ink cartridge information storage unit, and the comparison determination unit, The remaining ink amount derived by the remaining ink amount deriving unit and the remaining amount read by the reading unit Wherein the ink remaining amount, compares, based on the comparison result, an ink cartridge determination system, wherein the ink cartridge is determined whether the registered product. 4. An ink cartridge mounted on a printer, comprising a recording section for recording identification information indicating a registered product, wherein the identification information is an identification code of the ink cartridge, The first generated by encrypting the identification information with the first secret key
First additional information obtained by calculating the exclusive OR of the encrypted information and the random number, second encrypted information generated by encrypting the random number with the second secret key, and generated An ink cartridge, comprising: second additional information obtained by calculating an exclusive OR of the first encrypted information. 5. The ink cartridge according to claim 4, wherein the identification information further includes information on a manufacturing time of the ink cartridge. 6. An ink cartridge determination method for determining whether or not an ink cartridge mounted in a printer is a registered product, based on information recorded in a recording section of the ink cartridge. (A) preparing first and second secret keys, and (b) at least the identification code of the ink cartridge among the information recorded in the recording section, and the first and second additional information. , And (c) encrypting the read identification code with the first secret key to generate first encrypted information, and (d) reading the first additional information. Calculating an exclusive OR with the generated first encrypted information to obtain a first logical operation value; (e) the read second additional information and the generated first cipher Exclusive logic with activation information Calculating a value to obtain a second logical operation value, and (f) encrypting the acquired first logical operation value with the second secret key to generate second encrypted information. ) The acquired second logical operation value and the generated second
And a step of comparing the encrypted information with the encrypted information and determining whether or not the ink cartridge is a registered product based on the comparison result.