JP2001273111A - Print data distribution system and printing device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a print data distribution system capable of distributing print data in a form in which the number of uses is limited. A print data distribution system includes a recording medium on which some distribution print data that cannot be printed by a normal printing apparatus is recorded, and a data ID of each distribution print data recorded on the recording medium. And a data distribution center 50 that can create a magnetic card 55 on which a usage count designation value is recorded, and a magnetic card 55 mounted on the magnetic card reader / writer 17 when distribution print data is received. The data ID included in the print data for distribution is stored, and the print data for distribution is printed and the use of the print data in the magnetic card 55 is performed only when the corresponding usage count designation value is “1” or more. Includes printing device 10 that reduces the number-of-times designation value by "1".

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a print data distribution system and a printing apparatus.

[0002]

2. Description of the Related Art As is well known, a general computer is configured such that various electronic data can be easily transmitted and received via a portable recording medium such as a floppy disk, an MO, or the Internet or a LAN. .

[0003]

As described above, since the computer is configured to easily transmit and receive electronic data, it is desired to limit the number of times of use due to print data distributed for a fee and copyright. There is a problem that print data can be printed any number of times.

Accordingly, an object of the present invention is to provide a print data distribution system capable of distributing print data in a form in which the number of uses is limited, and a printing apparatus that can be used to constitute such a print data distribution system. , To provide.

[0005]

In order to solve the above-mentioned problems, a print data distribution system according to a first aspect of the present invention is a distribution data output unit that outputs distribution data that is print data in a special format. , And a data ID as identification information of the distribution data output by the distribution data output means, and a usage count designation value indicating the number of times the distribution data is permitted to be used is rewritable. And a print data supply device including a use count limited medium creating unit for creating a use count limited medium that is a simple recording medium.

Further, the print data distribution system includes a communication unit for performing communication with a device connected via a communication medium, and a printing unit for performing printing on paper in accordance with supplied data in a predetermined format. When the distribution data is received by the medium reading / writing means and the communication means for reading information from the mounted usage-limited medium and writing information to the mounted usage-limited medium. In the medium reading / writing means, a data ID included in the data for arrangement is stored, and a use frequency limited medium in which a value of “1” or more is stored as a use frequency designation value related to the data ID. Judge whether or not it is installed, and generate data in a predetermined format based on the received distribution data only when such a media with limited usage count is installed. Is supplied to the printing means Te,
Distribution data processing means for subtracting "1" from the use frequency designation value corresponding to the data ID included in the received distribution data in the use frequency limited medium mounted on the medium reading / writing means And a printing apparatus having a normal print data processing means for generating data of a predetermined format based on the print data and supplying the data to the printing means when the normal print data is received by the communication means.

That is, the printing apparatus included in the print data distribution system has a function of printing distribution data that is print data in a special format (a format that cannot be printed by a normal printing apparatus) (distribution data processing means and Printing means). Then, when the distribution data is received by the communication unit, the printing apparatus
The above function is actually used only when the use count designation value for the distribution data stored in the use count limiting medium attached to the medium reading / writing means is "1" or more. It has a configuration in which printing is performed. In addition, when printing the distribution data, the printing apparatus performs a process of subtracting “1” from the corresponding use frequency designation value in the use frequency limited medium.

Since the printing apparatus operates as described above, according to the present print data distribution system, print data (distribution data) can be distributed with the number of uses restricted.

When the present print data distribution system is realized, a means for outputting distribution data to a portable recording medium such as a flexible disk may be used as the distribution data output means of the print data supply device. What outputs to a communication medium may be used. Further, various media can be used as the medium for limiting the number of times of use, but it is preferable to use the medium for limiting the number of times of use in consideration of the amount of information to be stored, cost, size, and the like.

[0010] A print data distribution system according to a second aspect of the present invention uses a given public key to encrypt print data to be printed by a printing apparatus, and to encrypt the print data. A print data supply device including an encrypted print data generating unit that generates encrypted print data that is data including a data ID that is identification information and a usage count designating value that indicates the number of times the use of the print data is permitted. including.

The print data distribution system communicates with a device connected via a first communication medium, and prints on paper in accordance with the supplied data in a predetermined format. A printing unit, an information storage unit that stores a public key and a secret key for decrypting information encrypted using the public key, and an information storage unit that stores a correspondence relationship between a data ID and a use frequency designation value. Request response means for returning the public key stored in the information storage means to the transmission source of the public key provision request using the communication means when the public key provision request is received by the use status information storage means and the communication means When the encrypted print data is received by the communication unit, the use status information storage unit is in the first state where the data ID included in the encrypted print data is not stored, Whether the information storage means is in the second state in which the data ID included in the encrypted print data is stored and a value of “1” or more is stored as the usage count designation value for the data ID; It is determined whether it is in any other state, and if it is in the second state, the received encrypted print data is decrypted using the secret key stored in the information storage means, and a predetermined value is determined based on the decryption result. Format data is generated and supplied to the printing unit, and a print control / number change process for subtracting “1” from the usage count designation value in the usage status information storage unit is executed.
If it is in the state, after storing the data ID and the usage count designation value included in the received encrypted print data in the usage status information storage means, the print control / count change processing is executed, and If it is, the encrypted print data processing means for discarding the received encrypted print data;
And a printing device including a normal print data processing unit that generates data of a predetermined format based on the print data and supplies the data to the printing unit when the normal print data is received by the communication unit.

That is, the printing apparatus included in the print data distribution system has a function of outputting a public key corresponding to a private key held by the printing apparatus, but does not have a function of outputting a private key. Then, based on the given public key, the print data supply device generates encrypted print data that can be decrypted only by a printing device having a private key corresponding to the public key. In addition, the encrypted print data generated by the print data supply device includes a data ID and a usage count designation value.

When the printing apparatus receives encrypted print data for a certain print data for the first time, the data ID and the number-of-times-of-use designation value included in the encrypted print data are stored in the usage status information storage means. Is stored. Thereafter, each time the encrypted print data is printed, the usage count specification value is decreased by “1”, and when the usage count specification value is “0”, the printing of the encrypted data is no longer performed. Unable to perform (state determined by encrypted print data processing unit to be neither of first nor second state)
Is formed.

As described above, this print data distribution system is also a system that can distribute print data (distribution data) in a form in which the number of uses is limited.

In constructing the print data distribution system, a host computer connected to the printing apparatus is used as an element of the system, and the print data supply apparatus is configured to generate encrypted print data via a second communication medium. When the public key is received from the host computer,
It is desirable to employ means for generating encrypted print data and transmitting the generated encrypted print data to the host computer via the second communication medium. If the print data distribution system is configured as described above, print data can be distributed at high speed. In configuring the print data distribution system as described above, the second communication medium may be the same as or different from the first communication medium. In other words, the printing device may function as a local printer of the host computer, and the printing device may be a network printer connected to a network to which the host computer and the print data distribution device are connected. .

A printing apparatus according to the present invention includes a communication unit for communicating with a device connected via a communication medium, and a printing unit for performing printing on paper in accordance with supplied data in a predetermined format. And a data ID which is identification information of the data for distribution, and a usage frequency limited medium which is a rewritable recording medium in which a usage frequency designation value indicating the number of times the distribution data is permitted to be used is mounted. A medium reading / writing means for reading information from the mounted usage-limited medium and writing information to the mounted usage-limited medium; and a distribution means. When the application data is received, the data ID included in the arrangement data is stored in the medium reading / writing means, and “1” is used as the usage count designation value for the data ID. It is determined whether or not a medium with a limited number of uses in which the above values are stored is mounted, and only when such a medium with a limited number of uses is mounted, a predetermined format based on the received distribution data is determined. Generates data and supplies it to the printing means, and specifies the number of times of use corresponding to the data ID included in the received distribution data in the medium for limiting the number of uses attached to the medium reading / writing means. Distribution data processing means for subtracting "1" from the value, and normal print data processing for generating data of a predetermined format based on the print data and supplying the data to the printing means when the normal print data is received by the communication means Means.

According to another aspect of the present invention, there is provided a printing apparatus comprising: a communication unit for performing communication with a device connected via a communication medium; Printing means for performing printing on paper, information storage means for storing a public key, and a secret key for decrypting information encrypted using the public key, and encrypted print data received by the communication means A use status information storage unit for storing the data ID included in the file and the use count designation value in association with each other, and providing the public key using the communication unit when the communication unit receives the public key provision request Request responding means for returning the public key stored in the information storage means to the source of the request; and when the encrypted print data is received by the communication means, the encrypted print data is included in the usage status information storage means. Or the data ID included in the encrypted print data is stored in the use status information storage means, and the usage count designation value for the data ID is " It is determined whether it is in the second state where a value of 1 "or more is stored or in any other state. If it is in the second state, the received encrypted print data is stored in the information storage means. Decryption using the secret key stored in the storage device, generates data in a predetermined format based on the decryption result, supplies the data to the printing means, and uses the data corresponding to the data ID included in the received encrypted print data. A print control / number change process for subtracting “1” from the use number designation value in the information storage means is performed. If the print state is in the first state, the data ID and the use number included in the received encrypted print data are used. After storing the specified number of times in the usage status information storage means, the print control and the number of times change processing are executed, and if the status is in any other state, the received encrypted print data is discarded. A normal print data processing unit that generates data of a predetermined format based on the print data and supplies the data to the printing unit when the normal print data is received by the communication unit;

By using these printing apparatuses, the print data distribution system according to the first or second embodiment of the present invention can be configured.

[0019]

Embodiments of the present invention will be specifically described below with reference to the drawings.

First Embodiment First, an outline of a print data distribution system according to a first embodiment of the present invention will be described with reference to FIG.

As schematically shown in FIG. 1, a print data distribution system according to the first embodiment
And a host computer 40 connected to the printing apparatus 10 and a data distribution center 50 (print data supply apparatus). The data distribution center 50 is a computer having a magnetic card writer and functioning as a medium for limiting the number of use times and a distribution data generating unit. The data distribution center 50 holds several types of distribution print data. Data distribution center 50
The print data for arrangement held in the printer 10
Print data in a special format (a format that cannot be printed by a normal printing device) prepared for distribution to the users. , And a data ID indicating the type of the print data for distribution (distribution print data). More specifically, the print data for arrangement used in the present embodiment includes information indicating that it is print data for distribution and a data ID indicating the type of the print data for distribution (distribution print data). The normal print data is a continuation of DES-encrypted data using a predetermined key, and the printing device 10 stores the predetermined key.

The data distribution center 50 has a function of generating a use count restriction card 55 (use count restriction medium) and a distribution data recording medium 56. The usage count restriction card 55 is a magnetic card in which a data ID relating to some distribution print data and a usage count designation value that defines the number of times each distribution print data can be used for printing are recorded. The distribution data recording medium 56 is a card 5 for limiting the number of times of use.
5 is a recording medium (a flexible disk in this embodiment) in which a file of each print data for distribution in which a data ID is recorded is recorded. In addition, the user can send a creation request (distribution print data distribution request) specifying the type of print data for distribution (data ID) by e-mail or mail. When received, it is created and distributed by mail to the user.

The host computer 40 is a computer having a general configuration, and stores the contents of the distribution print data file recorded in the distribution data recording medium 56 in the printing apparatus 1.
0 (the print data file for distribution is
0 port). A printer driver and the like for the printing apparatus 10 are also installed in the host computer 40, and the host computer 40 is also used to create normal print data and supply the same to the printing apparatus 10.

The printing device 10 is a device that can print distribution print data and print normal print data. However, the printing device 10 refers to / updates information recorded in the usage count restriction card 55 when printing the distribution print data.
5 is provided with a magnetic card reader / writer 17 (medium reading / writing means).

Specifically, as shown in FIG. 2, the printing apparatus 10 includes a magnetic card reader / writer 17, a control panel 18, a printing mechanism 19, and a control unit 20.
The magnetic card reader / writer 17 is a device for reading and rewriting information stored in the usage count specifying card 55. The control panel 18 is an interface between the user and the printer 10, and includes a plurality of buttons for operating the printer 10, several LEDs for displaying an operation state of the printer 10, and a liquid crystal panel. ing. The printing mechanism 19 is a mechanism that functions as a printing unit, and actually performs printing on paper. The printing apparatus 10 is a so-called laser beam printer, and the printing mechanism 19 includes a paper feeder, a paper transport mechanism, a toner cassette, a print engine, and the like.

The control unit 20 includes a host interface circuit 21, a CPU 22, a RAM 23, an EEPROM (electri
A callable erasable and programmable ROM) 24, a memory control unit 25, a ROM 26, and an interface circuit unit 27 are provided.

The host interface circuit 21 is a circuit that receives normal print data and print data for distribution transmitted from the host computer 40. The ROM 26 is a memory in which programs and fonts are stored. CPU2
2 is a control circuit for controlling each unit in the control unit 20,
It functions as a distribution data processing unit and a normal print data processing unit in cooperation with other units. This CPU 22 executes R
The program stored in the OM 26 is read onto the RAM 23, and operates according to the read program. Also,
At that time, the CPU 22 uses the RAM 23 to temporarily store data received by the host interface circuit 21 and data generated by itself based on the data. The EEPROM 24 stores the printing device 10
Is a non-volatile memory used for storing data defining default operating conditions.

The memory control unit 25 sends a command from the host interface circuit 21 to the RAM 23 in accordance with an instruction from the CPU 22.
To transfer the data to the printing mechanism 1
9 to transfer data to the print engine. The interface circuit unit 27 includes a CPU 22 that controls the magnetic card reader / writer 17, the control panel 18,
It comprises several interface circuits for exchanging information with a transport mechanism or the like in the printing mechanism 19. That is,
The CPU 22 accesses the use number limiting card 55 set in the magnetic card reader / writer 17 via the interface circuit unit 27. Also, the CPU 22
Recognizes the state of each button in the control panel 18 (whether or not each button is pressed) via the interface circuit unit 27, and
ED, controls the liquid crystal panel. Further, the CPU 22
Via the interface circuit unit 27, the state of various mechanisms in the printing mechanism 19 (remaining toner amount of the toner cassette, presence / absence of paper jam, etc.) is recognized, and the control thereof is performed.

The operation and use of the printing apparatus 10 will be described below with reference to FIG.

A user of the printing apparatus 10 prints any distribution print data recorded in the distribution data recording medium 56 (or a copy of the distribution print data generated in the host computer 40). In such a case, the use number limiting card 55 is set in the magnetic card reader / writer 17 of the printing apparatus 10. By operating a keyboard or the like of the host computer 40, the host computer 40 is caused to transmit desired distribution print data to the printing apparatus 10.

On the other hand, as shown in FIG. 3, when the printing apparatus 10 (CPU 22) is started, it takes a state of waiting for data to be received by the host interface circuit 21 (step S101; NO). . Then, when data starts to be received (step S101; YE
S), the CPU 22 determines whether the received data is normal print data or distribution print data based on the data included at the beginning of the data that has begun to be received by the host interface circuit 21 (S). Step S102). If the data is normal print data (step S102; NO), the CPU 22 performs a process according to the content of the print data and supplies it to the printing mechanism 19 (print engine) (step S10).
3). That is, when the print data is described in a high-level language, the CPU 22 interprets the contents of the print data, generates an intermediate code, expands the generated intermediate code into image data, and supplies the image data to the printing mechanism 19. Do. If the print data is image data, the CPU 22
The process of supplying the printing mechanism 19 almost as it is is performed. Then, the CPU 22 returns to Step S101 and waits for data to be received by the host interface circuit 21.

When the data received by the host interface circuit 21 is distribution print data (step S102; YES), that is, at the beginning, information indicating distribution print data and a data ID are added. If the data includes the data, the CPU 22 determines whether or not the use count restriction card 55 is attached to the magnetic card reader / writer 17 (step S104). When the number-of-times-of-use restriction card 55 is not attached to the magnetic card reader / writer 17 (step S104; N
O), the CPU 22 includes the host interface circuit 21
Nothing is performed on the data received by (the data is discarded and the data reception is interrupted), and the process returns to step S101.

When the number-of-times-restricted card 55 has been mounted on the magnetic card reader / writer 17 (step S10)
4; YES), the CPU 22 reads, from the usage count restriction card 55, the usage count designation value related to the data ID (hereinafter referred to as the processing target data ID) included in the received distribution print data, and It is determined whether the value exceeds "0" (step S105). When the usage count specification value related to the processing target data ID is not stored in the usage count restriction card 55, and when the processing target data I stored in the usage count restriction card 55
When the usage count designation value for D is “0” (step S105; NO), the CPU 22 does nothing to the data received by the host interface circuit 21, and returns to step S101.

When the number-of-times-of-use specification value for the data ID to be processed exceeds "0" (step S105; YE)
S), the CPU 22 subjects the received data (distribution print data) to processing for distribution print data (D).
Normal print data is obtained by decrypting the ES encryption, and necessary processing is performed on the print data (step S106). Next, the CPU 22
By controlling the magnetic card reader / writer 17, the processing target data ID
The use number designation value for the application is decremented by "1" (step S107). Thereafter, the CPU 22 proceeds to step S
Returning to step 101, the system waits for data to be received by the host interface circuit 21.

That is, the printing apparatus 10 included in the print data distribution system according to the first embodiment has a function of printing distribution print data that cannot be printed by a normal printing apparatus. When the print data for distribution is supplied from the host computer 40, the printing apparatus 10
Only when the usage count specification value for the distribution print data stored in the usage count restriction card 55 is "1" or more, the distribution print data is printed using the above function. Further, when printing the distribution print data, the printing apparatus 10 performs a process of reducing the corresponding usage count designation value in the usage count restriction card 55 by “1”.

Since the printing apparatus 10 operates in this manner, according to the present print data distribution system, it is possible to distribute print data in a form in which the number of uses is limited.

<Second Embodiment> FIG. 4 shows the configuration of a print data distribution system according to a second embodiment of the present invention.

As shown, the print data distribution system according to the second embodiment includes a printing device 12 and a printing device 12.
And a data distribution center 52 (print data supply device) connected to the host computer 42 via the Internet. Although FIG. 4 shows only one printing device 12, the present print data distribution system usually includes
It is operated including a plurality of printing devices 12 and a plurality of host computers 42 connected to them.

The printing device 12 included in the print data distribution system has substantially the same hardware configuration as the printing device 10 in the first embodiment. However, the printing device 12
Is a device that does not include the magnetic card reader / writer 17. The EEPROM 2 in the printing device 12
4 is also used to store a public key, a secret key, and a use count management table 35. That is, in the present embodiment, the EEPROM 24 functions as an information storage unit and a use status storage unit. The details of the public key, secret key, and usage count management table 35 will be described later. However, the printing apparatus 10 stores the usage count management table 35 in the EEPROM 24 in which the public key and the secret key are not stored and has no content. Shipped as it exists.

The configuration and operation of the data distribution center 52 and the host computer 42 will be described below with reference to FIG.

As shown, the data distribution center 52
Holds a plurality of types of print data for distribution to be distributed to purchasers of the printing apparatus 12, similarly to the data distribution center 50. However, the distribution print data held by the data distribution center 52 is print data that can be printed by a normal printing device.

Also, the data distribution center 52
Base file server (computer having functions as WWW server and FTP server)
When receiving a request for introduction information of a predetermined content from each host computer 42, it returns introduction information indicating what kind of print data for distribution is prepared to the transmission source of the request.

When the data distribution center 52 receives a data distribution request including the data ID and the public key, which are the identification information of the distribution print data, from each host computer 42, the data distribution center 52 uses the public key to It generates encrypted print data of the print data for distribution specified by the ID and returns it to the source of the data delivery request. In the data distribution center 52 of the present embodiment, encrypted print data is generated by the following procedure, and the host computer 42
Will be returned to

First, DES (data encryption standar)
A key for the encryption according to d) (hereinafter referred to as a DES key) is arbitrarily generated. Then, using the DES key, the data ID included in the data distribution request, the specified number of times of use specified in accordance with the data ID, and the distribution print data specified by the data ID are determined. DES encrypted data is generated. That is, by decryption, the data ID, the number of times of use specification value,
DES encrypted data from which the print data for distribution is obtained is generated. Next, at the beginning of the generated DES encrypted data, data type information indicating that the data is encrypted print data, a public key included in the data distribution request, and a cipher which is obtained by encrypting the DES key with the public key. The encrypted print data is added thereto to create encrypted print data, and the encrypted print data is returned to the host computer 42.

The data distribution request program 45 installed in the host computer 42 is a program (HTML data and an applet) executed on a Web browser. This data distribution request program 45
Is executed, the host computer 42 executes the following processing according to the user's instruction.

When an operation to output a key issuance request is performed, the host computer 42 transmits a key issuance request having predetermined contents to the printing apparatus 12. Then, the host computer 42 stores therein the data (public key) returned by the printing apparatus 12 as a response to the key issuance request as a public key to be incorporated in the data delivery request.

When a predetermined operation is performed, the host computer 42 acquires the introduction information from the data distribution center 52, and displays a screen (Web page) on which the distribution print data can be selected based on the acquired introduction information. To be displayed. When the distribution print data on the screen is selected by the user, the host computer 42 transmits the data ID of the selected distribution print data.
And a data delivery request including the stored public key to the data distribution center 52. Then, as a response to the data delivery request, the data distribution center 52
And saves the encrypted print data transmitted from the server as a file. When another predetermined operation is performed, the host computer 42 supplies the encrypted print data stored in the form of a file to the printing apparatus 12 (a process in which the printing apparatus 12 connects the encrypted print data file to the printing apparatus 12). (Copying to the specified print port).

Hereinafter, the operation of the printing apparatus 12 will be described in relation to the operation of the host computer 42 with reference to the flowcharts shown in FIGS.

The user of the printing apparatus 12 first causes the host computer 42 to execute the data distribution request program 45, and instructs the host computer 42 (data distribution request program 45) to output a key issuance request.
The host computer 42 that has received this instruction transmits a key issuance request to the printing device 12 as described above.

As shown in FIG. 6, the printing device 12 (CP
When activated, U22) takes a state of waiting for data to be received by the host interface circuit 21 (step S201; NO). Then, when the data is received (step S201; YES) and the data is a key issuance request (step S202; YES), C
The PU 22 first determines whether a public key and a secret key are stored in the EEPROM 24 (Step S2).
11).

When the public key and the private key are not stored in the EEPROM 24 (step S211; YE
S) In other words, when the printing device 12 is in the state at the time of shipment, the CPU 22 generates a secret key and a public key of the RSA public key system (step S212). The procedure for generating the secret key and the public key in step S212 is as follows.
This is the same as that generally performed when using the RSA public key system. That is, in this step, two large prime numbers are randomly generated, and a public key and a secret key are generated from those prime numbers.

Next, the CPU 22 stores the generated public key and secret key in the EEPROM 24 (step S21).
3) Then, control is performed to return the public key (in this case, the public key generated in the previous step) stored in the EEPROM 24 to the host computer 42 (step S214). Then, the CPU 22 determines in step S2
01, and waits for data to be received by the host interface circuit 21.

If the public key and the secret key are stored in the EEPROM 24 (step S211; YES), C
In step S214, the PU 22 generates the public key and the public key stored in the EEPROM 24 (in this case, the public key generated in response to the key generation request received in the past) without newly generating the public key and the secret key. The control for returning to the host computer 42 is performed. And CPU
22 returns to step S201, and waits for reception of data by the host interface circuit 21.

The printing apparatus 1 is controlled by the control of step S214.
The data (public key) sent from 2 is stored as a public key to be included in the data delivery request by the host computer 42 that has issued the key issuance request.

After the public key is prepared in the host computer 42 by instructing the output of the key issuance request, the user performs a predetermined operation on the host computer 42 to select the distribution print data. Is displayed on the display of the host computer 42, and the distribution print data to be downloaded is selected. By selecting the distribution print data, a data delivery request including the data ID of the distribution print data and the stored public key is transmitted to the data distribution center 52, and the file holding the encrypted print data is transmitted to the data distribution center 52. , Host computer 42
Generated within. Then, the user causes the host computer 42 to supply the encrypted print data in the file to the printing device 12 by performing a predetermined operation.

The CPU 22 in the printing apparatus 12 determines that the data received by the host interface circuit 21 is not a key issuance request (step S202;
NO), that is, if it is normal print data or encrypted print data, the operation as print data processing means is started. Then, the CPU 22 determines whether the received data is normal print data or encrypted print data based on the data included at the beginning of the data that has been received by the host interface circuit 21 (step S203). When the received data is normal print data (step S203; N
O), the CPU 22 performs a process according to the content of the print data and supplies it to the printing mechanism 19 (print engine) (step S204). That is, when the print data is described in a high-level language, a process of interpreting the contents of the print data to generate an intermediate code, expanding the generated intermediate code into image data, and supplying the image data to the printing mechanism 19 is performed. . If the print data is image data,
The process of supplying the printing mechanism 19 almost as it is is performed. Then, the CPU 22 returns to step S201 and waits for data to be received by the host interface circuit 21.

On the other hand, when the data received by the host interface circuit 21 is the encrypted print data (step S203; YES), the CPU 22
The public key included in the encrypted print data is EEPR
It is determined whether or not it is stored in the OM 24 (FIG. 7:
Step S221). When the public key and the private key are not stored in the EEPROM 24, or when the EEPROM 24
When the public key stored in the OM 24 does not match the public key in the encrypted print data (Step S221;
NO), the CPU 22 uses the host interface circuit 2
No processing is performed on the data received by step 1 (the data is discarded and the data reception is interrupted), and the process returns to step S201.

If the public key stored in the EEPROM 24 matches the public key in the encrypted print data (step S221; YES), the CPU 22
The data ID and the usage count designation value are obtained by decrypting a part of the encrypted print data (the leading part of the DES encrypted data) using the secret key stored in the storage key 24 (step S222). That is, the CPU 22 decrypts the encryption key data (the DES key is encrypted with the public key) subsequent to the public key in the encrypted print data with the secret key, and thereby obtains the DES key. obtain. Then
Using the DES key, the CPU 22 decrypts a part of the DES encrypted data (the data ID, the usage count designation value, and the distribution print data that are encrypted with the DES key) following the encryption key data. By doing so, the data ID and the usage count designation value are obtained.

Then, the CPU 22 sets the acquired data I
It is determined whether D is stored (registered) in the usage count management table 35 (step S223). If the acquired data ID is not stored in the use count management table 35 (step S223; NO), the data ID and the use count designation value acquired in step S222 are
It is stored (registered) in the usage count management table 35 in the EEPROM (step S224). Then, CPU2
2, decrypts the remaining data using the secret key stored in the EEPROM 24, performs necessary processing on the decrypted result (normal print data), and supplies the result to the printing mechanism 19 (step S226). Then, the CPU 22 executes the EEP
After decrementing the use count designation value in the use count management table 35 on the ROM 24 by “1” (step S227), the process returns to step S201.

On the other hand, when the acquired data ID is stored in the use frequency management table 35 (step S22)
3; YES), the CPU 22 determines whether or not the usage count designation value acquired in Step S222 exceeds “0” (Step S225). Then, when the usage count designation value is “0” (step S225; NO),
The CPU 22 does nothing to the data received by the host interface circuit 21 (discards the data and suspends the data reception), and proceeds to step S
Returning to 201 (FIG. 6). If the usage count designation value exceeds “0” (step S225; YES), the CPU 22
Performs the processing from step S226 described above.

As described in detail above, the printing apparatus 12 included in the print data distribution system according to the present embodiment
Has a function of outputting a public key corresponding to a private key held by itself, but does not have a function of outputting a private key. Then, based on the given public key, the data distribution center 52 generates encrypted print data that can be decrypted only by the printing device 12 having the private key corresponding to the public key. In addition, the encrypted print data generated by the data distribution center 52 includes a usage count designation value.

When the printing apparatus 12 first receives the encrypted print data related to a certain print data for distribution, the printing apparatus 12 compares the data ID and the usage count designation value included in the encrypted print data with the usage count. It is stored in the management table 35. Thereafter, each time the distribution print data is printed, the use count designation value is decreased by "1", and the distribution print data is supplied with the use count designation value being "0". If the data has not been printed (step S225: NO), the process for the data ends without performing printing.

Since the printing apparatus 12 operates as described above, according to the print data distribution system, the print data can be distributed with the number of uses restricted.

The print data distribution system according to the first embodiment is a system in which the print data for distribution can be printed by using any of the printing apparatuses 10 if the use count restriction card 55 is provided. The print data distribution system according to the second embodiment transmits a certain encrypted print data only by the printing device 12 that has generated the public key included in the data delivery request that triggered the generation of the encrypted print data.
It is a system that can print. That is, according to the print data distribution system according to the second embodiment, the print data can be distributed from the data distribution center 52 to the host computer 42 in a form in which the number of uses and the printing device 12 to be used are limited.

<Modifications> The print data distribution system according to each embodiment can perform various modifications. For example, the print data distribution system according to the first embodiment transmits data from the data distribution center 50 to the host computer 40.
Although the print data for distribution is distributed by the flexible disk, the distribution of the print data for distribution may be performed by communication. Conversely, the print data distribution system according to the second embodiment
In this system, data is exchanged between the data distribution center 52 and the data distribution center 52 by communication. However, data exchange between these devices may be performed by a floppy disk or the like.

The printing apparatus 12 according to the second embodiment
Is added to the function of generating a secret key and a public key, which makes the confidentiality of the secret key higher (when the configuration of the second embodiment is adopted, the manufacturer of the printing device 12 also Because there is no way to know). Therefore, without providing this function, the EEPROM 24 or the R
The secret key and the public key may be written and stored in the OM 26.

The printing apparatus 12 is configured so that the secret key and the public key are not regenerated (the processing is branched depending on the presence or absence of the key in step S211). When managing and limiting the number of distribution print data that can be downloaded by the user based on the number of public keys transmitted from the user in the data distribution center 50, the secret key and the public key are set to a maximum of N.
And a secret key corresponding to the public key included in the received encrypted print data is selected and decrypted, while a maximum of N sets of secret keys and public keys are stored in the EEPROM 24. Alternatively, the printing device 12 may be modified. In the printing device 12 according to the second embodiment, when the key is stored in the EEPROM 24, the public key is returned only when the printing device 12 is connected to all the computers connected to the printing device 12. This makes it possible to use the encrypted print data printing function (a data distribution request can be sent to the data distribution center 50 by executing the data distribution request program 45).

The printing apparatus 12 may be configured so that the operation of the control panel 18 generates a public key and a secret key and prints the public key. However, since the public key is large data, the second key
As in the embodiment, it is desirable that the input of the public key to the host computer 40 be performed by communication.

Further, in the print data distribution system according to the second embodiment, the print data for distribution is not directly encrypted with the public key because the encryption by the DES is more effective than the encryption by the public key. Is performed at high speed. Therefore, if the processing speed can be reduced,
The distribution print data may be directly encrypted with the public key, and the encrypted print data may be directly decrypted with the secret key. Further, encrypted print data is generated in which only a part (for example, a leading part) of the print data for one page is encrypted with the public key, and the remaining part is the normal print data. Thus, the data distribution center 52 may be configured so that the printing apparatus 12 may be configured to be able to decrypt such encrypted print data. However, in such a configuration, printing cannot be performed by another printing apparatus, but some data in the encrypted print data remains as data that can be processed. In addition, it is desirable to configure the system so that the entire distribution print data is encrypted in some way.

[0070]

According to the print data distribution system of the present invention, the print data can be distributed with the number of uses restricted.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a print data distribution system according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a printing device included in the print data distribution system according to the first embodiment.

FIG. 3 is a flowchart illustrating an operation procedure of a printing apparatus included in the print data distribution system according to the first embodiment.

FIG. 4 is a configuration diagram of a print data distribution system according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of an overall operation of a print data distribution system according to a second embodiment.

FIG. 6 is a flowchart illustrating an operation procedure of a printing apparatus included in a print data distribution system according to a second embodiment.

FIG. 7 is a flowchart illustrating an operation procedure of a printing apparatus included in a print data distribution system according to a second embodiment.

[Explanation of symbols]

 10, 12 Printing device 18 Control panel 19 Printing mechanism 20 Control unit 21 Host interface circuit 22 CPU 23 RAM 24 EEPROM 25 Memory control unit 26 ROM 27 Interface circuit unit 30 Toner cassette 40, 42 Host computer 35 Usage frequency management table 45 Data distribution Requesting program 50, 52 Data distribution center 55 Usage limit card (magnetic card) 56 Distribution data recording medium (flexible disk)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04L 9/32 B41J 29/00 Z H04N 1/44 H04L 9/00 671 F term (Reference) 2C061 AP01 BB17 CL10 HH01 HJ06 HK23 HN15 5B021 AA01 CC05 CC06 EE04 KK01 NN18 5B049 AA05 BB25 CC21 DD04 EE01 EE23 EE28 FF02 FF04 FF08 GG04 GG07 GG10 5C075 CD07 EE02 EE03 FF03 FF90 5J104 A1907

Claims (6)

[Claims] 1. A print data distribution system including a printing device and a print data supply device, wherein the print data supply device outputs distribution data that is print data in a special format. , And a data ID as identification information of the distribution data output by the distribution data output means, and a usage count designation value indicating the number of times the distribution data is permitted to be used is rewritable. And a use-number-limited medium creating means for creating a use-number-limited medium that is a simple recording medium, wherein the printing device is provided with a communication means for communicating with a device connected via a communication medium. A printing unit for performing printing in accordance with data of a predetermined format on a sheet, reading of information from the mounted use frequency limiting medium, and mounting of the use frequency Medium reading / writing means for writing information to the limited medium, and when the distribution data is received by the communication means, the medium reading / writing means includes the distribution data in the medium reading / writing means. A determination is made as to whether or not the use frequency limiting medium in which the data ID is stored and the value of “1” or more is stored as the usage frequency designation value for the data ID is loaded, and such usage frequency restriction is performed. Only when the medium is mounted, the data of the predetermined format is generated based on the received distribution data and supplied to the printing means, and the number of times of use mounted on the medium reading / writing means Distribution data processing means for subtracting "1" from the usage count designation value corresponding to the data ID included in the received distribution data in the restricted medium, and the communication A print data distribution system comprising: a normal print data processing unit that generates data of the predetermined format based on the print data and supplies the data to the printing unit when the normal print data is received by the unit. 2. The print data distribution system according to claim 1, wherein the use number limited medium is a magnetic card. 3. A print data distribution system including a printing device and a print data supply device, wherein the print data supply device should perform printing in the printing device using a given public key. Data ID which is data obtained by encrypting print data and which is identification information of the print data.
And an encrypted print data generating unit that generates encrypted print data that is data including a usage count designating value indicating the number of times that the print data is permitted to be used. Communication means for performing communication with a device connected via a PC, printing means for performing printing in accordance with data of a supplied predetermined format on paper, a public key, and encryption using the public key. Information storage means for storing a secret key for decrypting the encrypted information, usage status information storage means for storing the correspondence between the data ID and the number of times of use specification value, and a request for providing a public key by the communication means. Request receiving means for returning the public key stored in the information storage means to the transmission source of the public key provision request using the communication means when received, and encryption by the communication means. When the print data is received, the data I contained in the encrypted print data in the usage information storage means
D is in the first state in which D is not stored, or the data ID included in the encrypted print data is stored in the use status information storage means, and "1" is used as the number-of-times specification value for the data ID. It is determined whether the state is a second state in which the above value is stored or not, and if the state is the second state, the received encrypted print data is stored in the information storage unit. And decrypts the data in the predetermined format based on the decryption result and supplies the data to the printing unit. Is executed, the data ID included in the received encrypted print data and the specified usage count value are stored in the usage status information storage unit. After storing, executing the printing control and the number changing process, if there in a non their state,
An encrypted print data processing unit for discarding the received encrypted print data; and, when the normal print data is received by the communication unit, generate the data in the predetermined format based on the print data to generate the print data. A print data distribution system comprising a normal print data processing means for supplying the print data to the means. 4. The apparatus further comprises a host computer connected to the printing apparatus, wherein the encrypted print data generating means of the print data supply apparatus receives the public key from the host computer via a second communication medium. 4. The print data distribution system according to claim 3, wherein the encrypted print data is generated, and the generated encrypted print data is transmitted to the host computer via the second communication medium. 5. Communication means for performing communication with a device connected via a communication medium, printing means for performing printing on paper in accordance with supplied data in a predetermined format, distribution data This is a means in which a use frequency limited medium, which is a rewritable recording medium, in which a data ID as identification information of the data and a usage frequency designation value indicating the number of times the distribution data is permitted to be used is mounted. Medium reading / writing means for reading information from the mounted use frequency limited medium and writing information to the mounted use frequency limited medium; and When data is received, a data ID included in the arrangement data is stored in the medium reading / writing means, and the data ID
It is determined whether or not the use number-limited medium storing a value of "1" or more as the use number-specific value is mounted, and only when such a use-number restricted medium is mounted, reception is performed. The data of the predetermined format is generated based on the received distribution data and supplied to the printing means, and the data for distribution received in the limited use number medium mounted on the medium reading / writing means. A distribution data processing unit for subtracting "1" from a usage count designation value corresponding to a data ID included in the data, and when normal communication data is received by the communication unit, the predetermined data is determined based on the printing data. A printing apparatus, comprising: a normal print data processing unit that generates data in a format and supplies the generated data to the printing unit. 6. A communication device for performing communication with a device connected via a communication medium, a printing device for performing printing on paper in accordance with a supplied data of a predetermined format, and a public key. Information storage means for storing a secret key for decrypting information encrypted using the public key; a data ID included in the encrypted print data received by the communication means; And a use status information storage unit for storing the information in association with a request for providing a public key provided by the communication unit. Request response means for returning the public key stored in the means; and when the encrypted print data is received by the communication means, the encrypted print data is included in the use status information storage means in the encrypted print data. First of that data ID is not stored
Or the data ID included in the encrypted print data is stored in the use status information storage means,
In addition, it is determined whether the data ID is in the second state in which a value of “1” or more is stored as the usage count designation value for the data ID, or in any other state. Decrypting the received encrypted print data using the secret key stored in the information storage unit, generating data in the predetermined format based on the decryption result, supplying the data to the printing unit, and Print control / number change processing for subtracting “1” from the use number designation value in the use state information storage means corresponding to the data ID included in the encrypted print data thus encrypted, and was in the first state. In this case, after storing the data ID and the usage count designation value included in the received encrypted print data in the usage status information storage unit, the print control / count change processing is executed, In the case where there is, the encrypted print data processing means for discarding the received encrypted print data, and when the normal print data is received by the communication means, the data of the predetermined format based on the print data And a normal print data processing means for generating and supplying the generated print data to the printing means.