JP2009258836A - Data converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data converter which rasterizes print data encrypted with a simple configuration. <P>SOLUTION: A printer 1 receives print data 30 in which job control information 31 and PDL (Page Description Language) data 32 are described. A job control information analysis section 111 analyzes job control information 31 and detects a job command which directs conversion of a character code. A text data conversion section 113 decrypts text data 322 described in the PDL data 32 based on a conversion table 52, and creates decrypted print data 40. A conversion table acquisition section 112 acquires the conversion table 52 from code image data 323 described in the PDL data 32 responding to the direction by the text data conversion section 113. A raster processing section 114 rasterizes decrypted print data 40 and creates raster data 400. A printer engine 12 prints the raster data 400 onto a print sheet. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a data conversion apparatus for rasterizing print data described in a page description language.

  In recent years, in offices and the like, a network system in which a personal computer (hereinafter referred to as “PC”), a printer, and the like are connected to a LAN (Local Area Network) is used. A PC user can print document data or the like using a printer connected via a LAN.

  The document data is converted into print data described in a page description language by a printer driver installed in the PC and transmitted to the printer. The printer that has received the print data prints raster data obtained by rasterizing the print data on a print sheet.

  Also, with the recent increase in security requirements, printers with enhanced security functions are often used. For example, Patent Document 1 discloses a printing system that enhances security when transmitting print data.

  In the printing system according to Patent Document 1, the PC encrypts print data created from document data. The encrypted print data is transmitted to the printer with a table command indicating the encryption table used for encryption added. The printer determines a decoding table to be used for decoding based on the table command. The printer decrypts the received print data using the determined decryption table, and executes print processing using the decrypted print data.

JP-A-10-91376

  As described above, the printing system according to Patent Document 1 can prevent a third party from monitoring print data transmitted to a printer via a network by encrypting the print data.

  However, in the printing system according to Patent Document 1, the PC encrypts print data using any one of a plurality of encryption tables. The printer must be provided with a non-volatile memory that holds a plurality of decryption tables corresponding to each encryption table in order to reliably decrypt the print data. For this reason, the conventional printing system has a problem that the configuration of the printer is complicated.

  In view of the above problems, an object of the present invention is to provide a data conversion apparatus capable of rasterizing print data encrypted with a simple configuration.

  In order to solve the above problem, the invention according to claim 1 is a table acquisition for acquiring a correspondence table indicating correspondence information between a character code described in the text data and a predetermined character code from print data including the text data. A text data conversion unit that converts a character code described in the text data based on the correspondence table, and replaces the text data with converted text data converted from the character code. And a raster processing unit that rasterizes the received print data.

  According to a second aspect of the present invention, in the data conversion device according to the first aspect, the correspondence table is included in the print data as a two-dimensional code, and the table acquisition unit is configured to perform the correspondence from the two-dimensional code. It includes a two-dimensional code processing unit that acquires a table.

  According to a third aspect of the present invention, in the data conversion device according to the first or second aspect, the print data includes instruction information indicating that the correspondence table is included, and the data The conversion device further includes an instruction unit that instructs the table acquisition unit to acquire the correspondence table when the instruction information is detected.

  The data conversion apparatus according to the present invention acquires correspondence information used for conversion of text data from print data including text data, and rasterizes the print data including text data converted based on the correspondence information. As described above, the data conversion apparatus according to the present invention does not need to hold correspondence information used for conversion of text data in advance, so that the configuration can be simplified.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a network system including a configuration of a printer 1 according to an embodiment of the present invention. The network system shown in FIG. 1 has a configuration in which a printer 1 and a PC 2 are connected to a LAN 3. The printer 1 is a network printer that prints the print data 30 transmitted from the PC 2. The PC 2 is a terminal device used by the user. The LAN 3 is provided with a router (not shown) for connecting to the Internet or another LAN.

  First, the configuration of the printer 1 will be described. The printer 1 includes a printer controller 11, a printer engine 12, and a LAN interface 13.

  The printer controller 11 performs rasterization of the print data 30 and the like. The printer controller 11 includes a job control information analysis unit 111, a conversion table acquisition unit 112, a text data conversion unit 113, and a raster processing unit 114.

  The job control information analysis unit 111 analyzes the job control information 31 described in the print data 30. The conversion table acquisition unit 112 analyzes the two-dimensional code included in the print data 30, and acquires the conversion table 52 used for decoding the text data 322, 322,. The text data conversion unit 113 decodes the text data 322 based on the conversion table 52. The raster processing unit 114 rasterizes the print data 30 or the decoded print data 40.

  The printer engine 12 prints raster data 300 and 400 on printing paper using an electrophotographic method, and outputs a print document 60. For this reason, the printer engine 12 includes an electrostatic drum, a developing device, a fixing device, and the like (not shown). The LAN interface 13 transmits / receives data to / from each computer connected to the LAN 3 using TCP (Transmission Control Protocol) / IP (Internet Protocol).

  Hereinafter, the operation of the printer 1 having the above-described configuration will be described. First, the overall flow of the operation of the printer 1 will be described. FIG. 2 is a flowchart showing an overall operation flow of the printer 1.

  First, a printer driver installed in the PC 2 converts the document data 20 into print data 30 in accordance with a user operation, and transmits the print data 30 to the printer 1. The document data 20 is data created by a user using document creation software installed on the PC 2. The print data 30 is described in a page description language such as PCL (Printer Control Language).

  When the printer 1 receives the print data 30 (Yes in Step S1), the job control information analysis unit 111 analyzes the job control information 31 (Step S2) and acquires the conversion flag information 51. The conversion flag information 51 is information indicating whether the text data 322 needs to be decrypted. The job control information analysis unit 111 determines the output destination of the print data 30 based on the conversion flag information 51 (step S3).

  If the conversion flag information 51 is OFF (No in step S3), the raster processing unit 114 rasterizes the print data 30 (step S5) and creates raster data 300. On the other hand, when the conversion flag information is ON (Yes in step S3), the text data conversion unit 113 decodes the text data 322, 322,... In the print data 30 (step S4), and outputs the decoded print data 40. To do. The raster processing unit 114 rasterizes the decoded print data 40 (step S5) and creates raster data 400. The printer engine 12 prints the raster data 300 or 400 on the printing paper (step S6), and outputs the print document 60.

  Next, the print data 30 will be described in detail. FIG. 3 is a diagram illustrating an example of the configuration of the print data 30. In the print data 30 shown in FIG. 3, job control information 31 is described at the head of the print data 30. The job control information 31 describes information for controlling the operation of the printer 1 such as the paper size and paper type. The job control information 31 is described using PJL (Printer Job Language) or the like.

  Following the job control information 31, PDL (Page Description Language) data 32 described in a page description language is described. Of the print data 30, PDL data 32 corresponds to the document data 20.

  The PDL data 32 includes command data 321, 321..., Text data 322, 322. The command data 321 includes various conditions relating to rasterization and information indicating an area where the text data 322 and the like are arranged. The code image data 323 is a two-dimensional code in which the conversion table 52 is recorded. A QR code (registered trademark) or the like is used as the two-dimensional code.

  The text data 322 is data corresponding to character information described in the document data 20. However, the character code described in the text data 322 is a character code (hereinafter referred to as “converted character”) obtained by converting the character code used in the document data 20 (hereinafter referred to as “used character code”) based on the conversion table 52. Code)). The used character code corresponds to Shift-JIS (Japan Industrial Standard) or the like. That is, the text data 322 is data in which character information described in the document data 20 is encrypted by the conversion table 52.

  The conversion table 52 is data indicating the correspondence between used character codes and converted character codes. For example, when the used character code is Shift-JIS, the conversion table 52 records correspondence information between the numerical value of the first byte of the used character code and the numerical value of the first byte of the converted character code. Furthermore, correspondence information between the numerical value of the second byte of the used character code and the numerical value of the second byte of the converted character code may be recorded in the conversion table 52.

  Although not shown in FIG. 3, the text data 322 is described together with a PDL command (hereinafter referred to as “text drawing command”) for instructing drawing of each text data 322. The code image data 323 is described together with a PDL command (hereinafter referred to as “image drawing command”) for instructing drawing of image data. In FIG. 4, the code image data 323 is not drawn on the raster data 300 and 400, but the code image data 323 may be drawn on the raster data 300 and 400.

  FIG. 4 is a diagram showing the display states of the raster data 300 and 400. In the raster data 400 created by rasterizing the decoded print data 40, the decoded text data 324 and 324 are drawn. Therefore, the character information is accurately displayed in the raster data 400.

  On the other hand, text data 322 and 322 are drawn in raster data 300 created by rasterizing the print data 30. As a result, the character information is displayed in the raster data 300 in a so-called garbled state. That is, when the character code of the text data 322 is converted based on the conversion table 52, the text data 322 needs to be decoded.

  Next, the analysis process (step S2) of the job control information 31 will be described in detail. FIG. 5 is a flowchart showing a flow of analysis processing of the job control information 31. First, the job control information analysis unit 111 turns off the conversion flag information 51 as an initialization process (step S21). The job control information analysis unit 111 reads the first line of the job control information 31 and acquires a job command to be analyzed (step S22).

  If the acquired job command instructs conversion of the character code (Yes in step S23), the job control information analysis unit 111 turns on the conversion flag information 51 (step S24). In the job control information 31 shown in FIG. 3, a job command 311 is a command for instructing character code conversion. The job control information analysis unit 111 reads the next line of the job control information 31 and acquires a new job command to be analyzed (step S25). Thereafter, the job control information analysis unit 111 returns to the process shown in step S23.

  On the other hand, if the acquired job command does not instruct character code conversion (No in step S23), the job control information analysis unit 111 checks whether the acquired job command indicates the end of the job control information 31. (Step S26).

  If the acquired job command does not indicate the end of the job control information 31 (No in step S26), the job control information analysis unit 111 acquires print setting information indicated by the acquired job command (step S27), and step Proceed to S25. The print setting information acquired by the job control information analysis unit 111 in step S27 is used in the print processing (step S6) of the raster data 300 and 400.

  On the other hand, when the acquired command indicates the end of the job control information 31 (Yes in step S26), the job control information analysis unit 111 ends the process illustrated in FIG. A job command 312 shown in FIG. 3 indicates that the page description language used in the PDL data 32 is PCL, and indicates the end of the job control information 31.

  Next, the decryption process (step S4) of the text data 322 will be described in detail. FIG. 6 is a flowchart showing the flow of the decoding process of the text data 322. First, the text data conversion unit 113 reads the first line of the PDL data 32 and acquires a PDL command to be processed (step S41).

  When the acquired PDL command is an image drawing command (Yes in step S42), the text data conversion unit 113 converts the image data instructed to be drawn by the image drawing command (hereinafter referred to as “instruction image data”) into a conversion table acquisition unit. 112. The conversion table acquisition unit 112 executes a conversion table acquisition process using the instruction image data (step S43). Although details will be described later, when the conversion table acquisition unit 112 acquires the conversion table 52, the conversion table 52 is registered in the text data conversion unit 113. The text data converter 113 reads the PDL data 32 of the next line and acquires a new PDL command (step S47).

  If the acquired PDL command is not an image drawing command (No in step S42), the text data conversion unit 113 checks whether the acquired PDL command is a text drawing command (step S44). When the acquired PDL command is not a text drawing command (No in step S44), the text data conversion unit 113 acquires a new PDL command (step S47).

  On the other hand, when the acquired PDL command is a text drawing command (Yes in step S44), the text data conversion unit 113 decodes the text data 322 corresponding to the acquired PDL command into decoded text data 324 based on the conversion table 52. (Step S45). The text data 322 corresponding to the acquired PDL command is replaced with the decrypted text data 324 (step S46). The text data conversion unit 113 acquires a new PDL command (step S47), and checks whether the new PDL command indicates the end of the PDL data 32 (step S48).

  When the end of the PDL data 32 is not instructed (No in step S48), the text data conversion unit 113 returns to the process shown in step S42. On the other hand, when the end of the PDL data 32 is instructed (Yes in step S48), the text data conversion unit 113 sends the print data 30 rewritten to the decoded text data 324 to the raster processing unit 114 as the decoded print data 40. Output (step S49). Thereby, the process shown in FIG. 6 is completed.

  Next, the conversion table acquisition process (step S43) will be described in detail. FIG. 7 is a flowchart showing the flow of the conversion table acquisition process (step S43). First, the conversion table acquisition unit 112 checks whether or not the conversion flag information 51 is ON (step S431).

  When the conversion flag information 51 is OFF (No in step S431), the conversion table acquisition unit 112 ends the process illustrated in FIG. On the other hand, when the conversion flag information 51 is ON (Yes in step S431), the conversion table acquisition unit 112 checks whether or not the conversion table 52 is registered in the text data conversion unit 113 (step S432).

  When the conversion table 52 is registered (Yes in step S432), the conversion table acquisition unit 112 ends the process illustrated in FIG. On the other hand, when the conversion table 52 is not registered (No in step S432), the conversion table acquisition unit 112 determines whether the instruction image data is a two-dimensional code (step S433).

  If the instruction image data is not a two-dimensional code (No in step S433), the conversion table acquisition unit 112 ends the process illustrated in FIG. On the other hand, when the instruction image data is a two-dimensional code (Yes in step S433), the conversion table acquisition unit 112 acquires information recorded in the two-dimensional code (instruction image data) (step S434). The contents are confirmed (step S435).

  When the acquired information is not the conversion table 52 (No in step S435), the conversion table acquisition unit 112 ends the process illustrated in FIG. On the other hand, when the acquired information is the conversion table 52 (Yes in step S435), the conversion table 52 is registered in the text data conversion unit 113 (step S436). Thereby, the process shown in FIG. 7 is completed.

  As described above, the printer 1 according to this embodiment decodes the text data 322 based on the conversion table 52 recorded in the print data 30. As a result, the printer 1 according to the present embodiment does not need to hold the conversion table 52 in advance, and the print data 30 including the text data 322 encrypted with a simple configuration is rasterized with a simple configuration. can do.

  In the present embodiment, the example in which the text data conversion unit 113 creates the decrypted print data 40 has been described. However, the present invention is not limited to this. For example, the text data conversion unit 113 may perform rasterization processing along with decoding of the text data 322. In this case, the process shown in FIG. 6 changes as follows.

  First, the text data conversion unit 113 creates white raster data 400 based on the job control information 31. If the conversion table 52 is not acquired in the process shown in step S43, the text data conversion unit 113 draws the instruction image data on the raster data 400 based on the image drawing command. Instead of the processing shown in step S46, the decoded text data 324 is drawn on the raster data 400 based on the text drawing command. If the acquired PDL command is not a text drawing command (No in step S44), the text data conversion unit 113 performs processing shown in step S47 after performing processing based on the acquired PDL command.

  In the present embodiment, the printer 1 has been described as an example of the data conversion apparatus of the present invention, but the present invention is not limited to this. For example, the data conversion apparatus of the present invention may be a PC that displays the print data 30 on a monitor. In this case, the PC includes a job control information analysis unit 111, a conversion table acquisition unit 112, a text data conversion unit 113, and a raster processing unit 114. When the user instructs the PC to display the print data 30, the PC creates raster data 400 from the print data 30 using the above-described components, and displays the raster data 400 on the monitor.

1 is a block diagram illustrating a functional configuration of a printer according to an embodiment of the present invention. 3 is a flowchart illustrating an overall operation flow of the printer. FIG. 3 is a diagram illustrating a structure of print data received by a printer. FIG. 4 is a diagram illustrating raster data created from print data and decoded print data. It is a flowchart which shows the flow of a job control information analysis process. It is a flowchart which shows the flow of a text data decoding process. It is a flowchart which shows the flow of a conversion table acquisition process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 11 Printer controller 12 Printer engine 13 LAN interface 111 Job control information analysis part 112 Conversion table acquisition part 113 Text data conversion part 114 Raster processing part

Claims (3)

A table acquisition unit for acquiring a correspondence table indicating correspondence information between a character code described in the text data and a predetermined character code from print data including text data;
A text data conversion unit that converts a character code described in the text data based on the correspondence table, and replaces the text data with converted text data in which the character code is converted;
A raster processing unit for rasterizing the print data replaced with the converted text data;
A data conversion device comprising: The data conversion device according to claim 1, wherein
The correspondence table is included in the print data as a two-dimensional code,
The table acquisition unit
A two-dimensional code processing unit for obtaining the correspondence table from the two-dimensional code;
The data converter characterized by including. In the data conversion device according to claim 1 or 2,
The print data includes instruction information indicating that the correspondence table is included,
The data conversion device further includes:
An instruction unit that instructs the table acquisition unit to acquire the correspondence table when the instruction information is detected;
A data conversion device comprising:

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