JP5091914B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  In recent years, document data in the XPS (XML Paper Specification) format (hereinafter referred to as XPS document data) has been used. XPS document data is compressed in ZIP format. For this reason, the XPS document data has a ZIP format. There is a printer that receives the XPS document data and performs printing according to the XPS document data (see, for example, Patent Document 1).

JP 2008-234506 A

  When the XPS document data is supplied to the printer as one file, for example, by a file transfer protocol, the end of the XPS document data can be detected as the end of the file. However, when XPS document data is supplied to a printer through a peripheral device interface such as a USB (Universal Serial Bus) or parallel interface, a plurality of continuous document data is supplied as a series of data streams. The end of data is not known, and it is difficult to supply a plurality of continuous XPS document data to the printer as separate print jobs.

  In some printers, a time-out period is provided, and document data is kept waiting until the time-out period elapses. When the time-out period elapses, one print job is determined and the print job is started. In this way, a plurality of continuous XPS document data can be supplied to the printer as separate jobs, but a delay of a timeout time occurs for each print job.

  In addition, when print data is described in a page description language and supplied to a printer, the end of data can be given explicitly using a device control language such as PJL (Printer Job Language), but the XPS format is used. The specification does not allow such data termination.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of continuously processing a plurality of XPS document data as separate print jobs.

  In order to solve the above problems, the present invention is configured as follows.

  An image forming apparatus according to the present invention includes a receiving unit that receives document data in XPS format, a process of reading a signature in the document data, specifying a field size based on the value of the signature, and advancing the data reading position by that size Until the signature indicating the end of central directory record is read, and when the end of central directory record is found by the XPS interpretation means, the end of central directory record is And a control means for determining a print job after one print job is completed.

  Thus, a plurality of XPS format document data can be continuously processed as separate print jobs using the end-of-central directory record. In addition, since data is skipped for each signature, the end of XPS format document data can be accurately detected even if data equivalent to the signature indicating the end of central directory record exists in the middle. .

  In addition to the image forming apparatus described above, the image forming apparatus according to the present invention may be configured as follows. In this case, the XPS interpretation unit specifies the type of the field at the data reading position based on the signature value, and specifies the size of the field from the type.

  In addition to the image forming apparatus described above, the image forming apparatus according to the present invention may be configured as follows. In this case, when the signature value indicates the local file header, the XPS interpretation means reads the size of the file data from the local file header, and sums the size of the local file header, the size of the file data, and the size of the data descriptor. Only the data read position is advanced.

  In addition to the image forming apparatus described above, the image forming apparatus according to the present invention may be configured as follows. In this case, the receiving means receives the document data in the XPS format at the peripheral device interface.

  In addition to the image forming apparatus described above, the image forming apparatus according to the present invention may be configured as follows. In this case, the peripheral device interface is a universal serial bus or a parallel interface.

  According to the present invention, a plurality of XPS document data received successively can be continuously processed as separate print jobs.

FIG. 1 is a block diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a data structure in the ZIP format. FIG. 3 is a flowchart for describing document data reception processing by the image forming apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. In FIG. 1, a communication device 1 is connected to a host device such as a personal computer and receives XPS document data through a peripheral device interface such as a USB or parallel interface.

  The image processing apparatus 2 is an apparatus that generates print data by performing image processing on image data extracted from document data. The print data is data for controlling the print engine 3.

  The print engine 3 is an apparatus that prints an image on printing paper according to print data.

  The computer 4 is a device that has a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown), loads a program into the RAM, and executes the program with the CPU.

  In the computer 4, the buffer 11 is a storage area that is provided in a RAM (not shown) and temporarily stores received document data.

  In the computer 4, various processing units are realized by executing the program by the CPU. In this embodiment, the XPS interpretation unit 12 and the control unit 13 are realized.

  The XPS interpretation unit 12 reads the signature in the XPS document data from the buffer 11, specifies the size of the field at the current data reading position based on the value of the signature, and advances the data reading position by that size. It is a processing unit that is repeatedly executed until a signature indicating an end-of-central directory record is read.

  XPS document data is data compressed in the ZIP format. FIG. 2 is a diagram showing a data structure in the ZIP format. As shown in FIG. 2, the ZIP format data includes one or more sets of local file header (Local File Header), file data (File Data) and data descriptor (Data Descriptor), central directory (Central Directory), In addition, an End Of Central Directory Record is included. The end of central directory record is located at the end of the ZIP data.

  The central directory has one or more file headers and a digital signature.

  Local file headers, file headers and digital signatures in the central directory, and end-of-central directory records have signatures at the beginning of them. The signature is 4-byte data and has a value specific to the field type. The signature value of the local file header is 0x04034b50. The value of the signature of the file header in the central directory is 0x02014b50. The signature value of the digital signature in the central directory is 0x05054b50. The value of the signature of the end of central directory record is 0x06054b50.

  These fields have a fixed length. However, the file data has a variable length, and its size is included in the local file header.

  The control unit 13 also controls the image processing apparatus 2 and the print engine 3, manages a print job corresponding to the received XPS document data, and executes the print job to cause the print engine 3 to perform printing. It is. When the XPS interpretation unit 12 finds an end-of-central directory record, the control unit 13 determines the print job with the end-of-central directory record ending as one print job.

  Next, the operation of the above apparatus will be described. FIG. 3 is a flowchart for describing document data reception processing by the image forming apparatus shown in FIG.

  When the XPS document data is received by the communication device 1, it is stored in order in the buffer 11 (step S1).

  Then, the XPS interpretation unit 12 reads a 4-byte signature from the beginning of the document data in the buffer 11 (step S2).

  The XPS interpretation unit 12 specifies the type of the field at the current data reading position from the value of the signature, and specifies the size of the field (step S3). At this time, if the field is a local file header, the XPS interpretation unit 12 reads the size of the file data from the local file header.

  The signature value, field type, and field size are associated with each other and stored in advance in a table (not shown), and the size of the field is specified by referring to the table.

  The XPS interpretation unit 12 advances the data reading position by the specified size (that is, up to the beginning of the next field) (step S4). At this time, if the field at the current data read position is a local file header, the local file header and the corresponding file data and data descriptor are skipped, and the data read position remains at the beginning of the next field. It is advanced.

  Further, the XPS interpretation unit 12 determines whether or not the signature value read in step S2 is a value indicating the end of central directory record (step S5).

  If the signature value read in step S2 is not a value indicating an end-of-central directory record, the XPS interpretation unit 12 performs the processes in steps S2 to S4 again for the current data reading position field.

  On the other hand, when the signature value read in step S2 is a value indicating an end-of-central directory record, the XPS interpretation unit 12 notifies the control unit 13 of the current data reading position. The control unit 13 sets the document data from the head of the data or the next field of the previous end-of-central directory record to the current data reading position as one print job, registers the print job in the queue, It is executed as it is (step S6).

  Then, the XPS interpretation unit 12 determines whether data follows the end of central directory record (step S7). If the data continues after the end of central directory record, processing for determining the next print job (steps S2 to S6) is executed. If no data follows the end of central directory record, the process ends.

  As described above, according to the embodiment, the communication device 1 receives XPS document data. The XPS interpretation unit 12 reads the signature in the document data, specifies the size of the field based on the value of the signature, and advances the data reading position by the size, and the signature indicating the end of central directory record is read. Run repeatedly until When the XPS interpretation unit 12 finds an end-of-central directory record, the control unit 13 determines the print job with the end-of-central directory record ending as one print job.

  As a result, even if a plurality of XPS document data are continuously received and stored in the buffer 11, the plurality of XPS document data can be used as separate print jobs using the end of central directory record. Can be processed continuously. That is, a subsequent print job can be processed immediately without waiting for the elapse of the timeout time as described above. Further, since data is skipped for each signature, the end of XPS document data can be accurately detected even if data having the same value as the signature indicating the end of central directory record exists in the middle.

  The above-described embodiments are preferred examples of the present invention, but the present invention is not limited to these, and various modifications and changes can be made without departing from the scope of the present invention. is there.

  The present invention is applicable to a printer connected to a personal computer via USB, for example.

1 Communication device (an example of receiving means)
12 XPS interpretation part (an example of XPS interpretation means)
13 Control unit (an example of control means)

Claims (5)

In an image forming apparatus that performs printing in accordance with XPS format document data,
Receiving means for receiving document data in XPS format;
The process of reading the signature in the document data, specifying the size of the field based on the value of the signature, and advancing the data reading position by the size is repeatedly executed until the signature indicating the end of central directory record is read. XPS interpretation means;
When an end-of-central directory record is found by the XPS interpreting means, control means for determining the print job with the end-of-central directory record as one print job as an end;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the XPS interpretation unit specifies a type of a field at a data reading position based on the value of the signature, and specifies a size of the field from the type.   If the signature value indicates a local file header, the XPS interpretation means reads the size of the file data from the local file header, and determines the size of the local file header, the size of the file data, and the size of the data descriptor. 2. The image forming apparatus according to claim 1, wherein the data reading position is advanced by the total amount.   The image forming apparatus according to claim 1, wherein the reception unit receives the document data in the XPS format through a peripheral device interface.   The image forming apparatus according to claim 4, wherein the peripheral device interface is a universal serial bus or a parallel interface.

Images