JPH09319530A - Printer driver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically select the most suitable page description language(PDL) on the side of a printer driver by judging the feature of print data, selecting the optimum PDL type out of plural kinds of PDL and preparing output data expressing the print data in the selected PDL. SOLUTION: When a data type decided by a data deciding part 3 is reported to a PDL selecting part 5, at the PDL selecting part 5, any type of PDL having ability for expressing the print data is selected while referring to a PDL ability table 6. When any specified PDL type can be determined, the feature of that PDL is reported to a PDL part 2 and its generating processing is instructed. When plural PDL types are left as candidates, at the PDL selecting part 5, the sum of predictive PDL time and data transfer time is found from result data in the past corresponding to the data type of print data concerning the plural candidate PDL types while referring to a data base 7 and the PDL type candidate, for which the estimated time is minimum, is selected and determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer driver for a printer that creates and prints a print image using a page description language, and more particularly, a printer driver for a printer that can interpret a plurality of types of page description languages. Regarding drivers.

[0002]

2. Description of the Related Art In recent years, printers capable of dealing with a plurality of page description languages have appeared with the advancement of printer functions. Considering a case where an application program running on a personal computer outputs print data created by the application program to a printer, as shown in FIG. 6, a page description language interpreted by the printer 14 (hereinafter abbreviated as PDL). The drawing command of 1) can be regarded as one type of image information expression format to be transferred between the personal computer 10 and the printer 14.

By using the PDL drawing command, the data transfer amount can be reduced as compared with the case where the image information to be printed is transferred to the printer as it is. Moreover, compatibility of print data can be maintained by using a standardized PDL. Further, by allowing the printer to accept (interpret) drawing commands of a plurality of types of PDL, it becomes possible to handle print data generated by a wider range of application programs on a personal computer.

By the way, in the operating system "WINDOWS" of Microsoft Corporation, as shown in FIG.
The print data sent from the application program 11 on "S" is GDI (Graphics Device Interface).
It is sent in the data format of a common interface called. This is the device interface processing unit (GD
I. EXE) 12 receives and passes the image information of the print data to the printer driver 13. The device interface processing unit (GDI.EXE) 12 that performs this process
This is a common interface processing function included in the WINDOWS operating system. That is, the device interface processing unit (GDI.EXE) 12
The image information of the print data sent from the application program 11 is received, the format is converted so as to be compatible with the printer driver 13, and the image information is passed. The printer driver 13 sends the image information to the physically connected printer 14 to the PDL corresponding to the printer.
And the compressed image is sent to the printer 14. The printer driver 13 will be prepared to be compatible with the physically connected printer 14.

In order to reduce the data transfer time to the printer, when the print data is sent to the printer, the print data is compressed inside the personal computer and once stored, it is sent. At this time, for example, JP-A-6
In order to further shorten the data transfer time to the printer, as in “Image forming system device” described in Japanese Patent Publication No. 292024-, when it is determined that the compression efficiency is poor, the other efficient compression method is applied. The print data is compressed by switching the data compression method. In this way, the transfer time to the printer is reduced by using the optimal compression method.

In this case, when the compressed data of the image information transferred to the printer is regarded as one type of image information representation format for passing between the personal computer and the printer, the compression method is selected. This has the same meaning as selecting one expression format of image information. In the sense that one expression format of image information is selected, it can be regarded as equivalent to selecting one PDL format from a plurality of PDL formats in the print data expression format in a printer that supports multi-PDL. .

By the way, in the case of a multi-PDL printer capable of supporting a plurality of PDLs, it is customary to provide a separate printer driver for each PDL. Therefore, when applying the above technique, the data transfer time to the printer is increased. In order to reduce the above, the compression of the data amount by the PDL is evaluated (determined), and the printer driver using the appropriate PDL is selected.

Regarding the technique of selecting a printer driver, for example, reference is made to "HP BIDs Farewell to 300".
dpi with New 4 ppm LaserJet 5L ”THE HARD COPY OBSE
RVER, Oct. 1995 ”can be referred to. According to this document, when installing the printer driver corresponding to the printer, depending on the environment in which the printer driver operates, for example, whether the operating system is Microsoft's "DOS" or "W"
Introducing a technology for selecting a printer driver to be installed according to "INDOWS", the size of CPU speed, the size of installed memory, and the like. For example, if the operating system is "W
In the case of a system that uses a high-speed CPU and has a large amount of memory in "INDOWS", install the printer driver for "Windows Printing System" that processes a larger amount of data, and set the operating system to "DOS". In an environment, a driver for PDL that processes a small amount of data is installed.

The document also introduces a technique for recognizing the type of an application program and automatically changing the operating parameters of the printer driver by the application program. According to this, for example, the product name "Microsof
In the case of an application program that focuses on graphics such as “t Power Point”, select a parameter that emphasizes the reproducibility of graphics and select an application that focuses on text, such as the product name “Microsoft Word” of Microsoft Corporation. For programs, select parameters that emphasize text reproducibility.

[0010]

By the way, in the case of applying the technique by the "image forming system apparatus" described in the above-mentioned JP-A-6-292024 to the printer driver, the image data to be transferred to the printer is actually transferred. You can't tell which compression method has the highest compression efficiency without first compressing it. Therefore, there is a problem in that it may have to be compressed many times, and it takes a lot of time for the conversion.

Further, the conversion of the expression format of data by data compression in the technique of "image forming system apparatus" described in Japanese Patent Laid-Open No. 6-202024 is replaced by conversion into PDL drawing commands (PDL conversion). , Multi PDL
Optimal PDL in printer driver of compatible printer
Applied to select the type of PDL
Since there is a difference in their own expression ability, if the PDL type is simply selected only by the compression efficiency, the image quality may be deteriorated.

As described above, the device interface processing unit (GDI.EXE) 12 receives the image information (drawing command) based on the print data output from the application program 11 (FIG. 7) so that it is compatible with the printer driver 13. Since it is converted to a different format and handed over, the printer driver 13 sends the PD for the connected printer.
Processing for expanding the L instruction and compressed image and sending to the printer 14 is performed. In that case, the application program 1
1 to the device interface processing unit (GDI.E
Since the drawing command is issued to the printer driver 13 via the XE) 12, the printer driver 13 receives the drawing instruction from the device interface processing unit (GDI.EXE) 12 and associates the instruction with the PDL command. become.

In this case, if the printer driver 13 corresponding to the printer has a sufficient drawing processing function of the PDL to be used, as shown in FIG. When there is a drawing function inquiry command (Enable) from the GDI.EXE) 12, it declares that it has the capability (GDIINFO), so that, for example, an ellipse drawing command “GDI. "Ellipse" is transmitted to the printer driver 13 having the same format as "OUTPUT (Ellipse)" via the device interface processing unit (GDI.EXE) 12, and the printer driver 13 outputs a PDL command (ellipse drawing) for ellipse drawing. It

However, when the PDL drawing processing function of the printer driver is not sufficient, as shown in FIG.
At the start of the operation, the printer driver 13 declares that the device interface processing unit (GDI.EXE) 12 does not have the capability even if there is a drawing function inquiry command (Enable). The ellipse drawing command sent from the application program 11 is replaced by a plurality of line drawing commands “OUTPUT (SCANLINE)” by the device interface processing unit (GDI.EXE) 12 and is instructed to draw. In this case, the printer driver 13 uses the line drawing command "OUTPUT (SCAN
Since the replacement of "LINE)" with the PDL command is not necessarily decomposed in an appropriate manner for the connected printer, the drawing quality is greatly deteriorated as compared with the case where the PDL command originally supports ellipse drawing.

Further, as in the technique described in the above document,
If the method of selecting the printer driver according to the system environment at the time of installation is used, it is possible to select the PDL according to the operating environment at the time of installation, but the same printer driver is always used after installation. Therefore, there is a problem that the PDL cannot be dynamically selected according to the print data.

Similarly, among the techniques described in the above-mentioned documents, according to the method of changing the operation parameter by the application program, the conversion parameter for one type of PDL is only changed according to the application program. In that case, multiple P
Even if the DL generation unit is installed, there is a problem that the plurality of PDLs cannot be selectively used and the PDL appropriate for the print data cannot be selected.

Here, the change of the conversion parameter is judged only by the kind of the limited number of application programs, not necessarily by judging the kind of the data. For this reason, when a document containing many texts is printed using a graphic-based application program, the effect of changing the parameters is not always obtained, and in some cases no processing is performed. There is a problem that it may be worse than.

The present invention has been made to solve these problems. An object of the present invention is to automatically select the most suitable PDL from the viewpoint of data transfer efficiency, data processing amount, and image quality on the printer driver side when a printer corresponding to a plurality of PDLs is used in the printer driver. It is to provide a printer driver that can do this.

[0019]

In order to achieve the above object, the printer driver of the present invention has, as a first feature, a determining means (3) for determining the feature of print data and a controlling printer. Selection means (5) for selecting an optimum type of page description language among a plurality of types of page description languages that can be used based on the judgment result of the judgment means, and expressing the print data in the selected type of page description language. And a creating unit (2) for creating the output data.

The printer driver of the present invention is the second one.
Characteristically, the selecting means selects an optimum type of page description language by referring to past generation time of the output data and transfer time of the output data to the printer.

According to the printer driver of the present invention having the above characteristics, when a printer corresponding to a plurality of page description languages is used, the printer driver has the points of data transfer efficiency, data processing amount, and image quality. The most appropriate type of page description language is automatically selected from. As the selection criterion, for example, when outputting to a multi-PDL printer, a PDL suitable for print data of a document is adopted based on statistical information such as the time required for PDL conversion in the past and the amount of data transfer and user-specified conditions. That is, in this selection criterion, the PDL suitable for the print data is selected according to the following three conditions. (1) The drawing quality desired by the user is satisfied. (2) PDL conversion time is short. (3) Data transfer time is short. The selection means holds such selection criteria, and the printer driver selects a multi-PD by selecting the optimum PDL by referring to the selection criteria held by the selection means.
An L-compatible printer can use the most suitable type of PDL for print data to send to the printer, and while maintaining the maximum drawing quality, the PDL conversion time and the data transfer time can be minimized. it can.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, modes for carrying out the present invention will be specifically described with reference to the drawings. FIG.
FIG. 3 is a block diagram showing a configuration of a main part of a printer driver according to an embodiment of the present invention. In FIG. 1, 1 is a device driver interface control unit (DDI control unit), 2 is a page description language command generation unit (PDL conversion unit), 3 is a data type determination unit, 4 is a temporary storage unit, and 5 is a page description language selection. Section (PDL selection section), 6 is a page description language ability table (P
DL capability table), 7 is a PDL conversion time / data transfer time database, 8 is a printer control unit, 9 is a user setting information setting unit, 12 is a device interface processing unit, 13 is a printer driver, and 14 is a printer.

In this embodiment, a printer driver operating on the "WINDOWS" operating system will be described as an example. When an application program running on the "WINDOWS" operating system outputs print data to a printer driver,
Print data is sent out through the interface program of the "WINDOWS" operating system. In that case, the print data is passed to the device interface processing unit (GDI.EXE) 12 in the graphics device interface (GDI) format, and further,
Device interface processing unit (GDI.EXE) 12
The data format is converted by and is passed to the printer driver 13.

In the printer driver 13, as shown in FIG. 1, the device interface processing unit (GDI.
The print data passed from the EXE 12 is received via a device driver interface control unit (hereinafter, abbreviated as DDI control unit) 1, and a page description language command generation unit (hereinafter, abbreviated as PDL conversion unit) 2 is received. The data is sent to the data type determination unit 3 as well as sent.

In this case, first, in the control processing of the DDI control unit 1, when the operation starts, first, the user setting information setting unit 9
Using the user setting information held in, the device interface processing unit (GDI.EXE) 12 is declared as a printer driver capability (PDL generation capability). The declaration of this capability is made based on, for example, the device interface processing unit (GDI.
It is used when it is desired to limit the drawing commands issued by EXE) 12.

Further, when the PDL designation of the user setting information is set to other than "automatic selection", the DDI control unit 1 has already designated the type of PDL to be used, and the corresponding PDL conversion is performed. The passed print data is directly sent to the copy unit 2. When the PDL designation of the user setting information is “automatic selection”, the passed print data is passed to the data type determination unit 3 and temporarily stored in the temporary storage unit 4.

The data type determination unit 3 determines the data type by examining the ratios of text, graphics and images included in the received print data. The determined data type is the page description language selection section (hereinafter, P
(Abbreviated as DL selector) 5). The print data itself at this time is temporarily stored in the temporary storage unit 4.

When the data type determined by the data type determination unit 3 is transmitted to the PDL selection unit 5, the PD
In the L selection unit 5, a page description language ability table (hereinafter, PDL
6, which is abbreviated as a capability table, and selects a type of PDL having a capability sufficient to express the received print data. If one specific PDL type can be determined here, the determined PDL type is transmitted to the PDL conversion unit 2 to instruct the PDL rendering command generation process (PDL conversion process) for the determined PDL type.

The PDL selector 5 selects P to be selected.
When a plurality of DL type candidates remain, the PDL conversion time / transfer time database 7 is referred to, and for each of the plurality of candidate PDL types, from the past actual data (statistical information) for the print data type, the PDL is used. The estimated time of the sum of the prediction time of data conversion and the predicted time of data transfer is calculated, and the candidate of the type of PDL that minimizes the estimated time is selected to determine the type of PDL. And the decided PD
The type of L is transmitted to the PDL conversion unit 2, and the PDL conversion processing is instructed.

In the PDL conversion section 2, the PD of the designated type
With L, each drawing command corresponding to the print data is generated and output to the printer control unit 8. The printer control unit 8 sends the received PDL drawing command to the printer device 1.
4

FIG. 2 is a flowchart showing a series of operations of control processing by the printer driver. That is,
As shown in FIG. 2, the operation of the control process by the printer driver receives the print data by the device driver interface (DDI) and starts the operation of the control process (step 21), and determines the data type of the print data. (Step 22). Based on this determination result, it is determined whether the print data includes graphics or an image (step 23). When graphics or images are included, the number of drawing commands that do not directly correspond to the PDL capability table is counted and the minimum PDL is selected (step 24). It is determined whether or not one PDL is determined by the selection (step 25).

When the number of PDLs is not determined to one, or when graphics or images are not included, the statistical data is referred to and the PDL having the smallest sum of the PDL conversion prediction time and the transfer prediction time is selected (step 26). ). As a result, the optimum PDL can be determined, so that the PDL selected here converts the data to be printed into PDL and transmits it to the printer (step 27).

Next, the elements (each module) constituting such a printer driver will be further described. The user setting information setting unit 9 sets capability declaration information to the device interface processing unit (GDI.EXE) 12 and PDL designation information.

The capability declaration information to the device interface processing unit (GDI.EXE) 12 here is designated when it is desired to limit drawing commands issued from the device interface processing unit (GDI.EXE) 12. In the normal case, "all abilities" are specified (default value).

The device interface processing unit (G
DI. The drawing function (PDL command) corresponding to the drawing command issued from EXE 12 is finally determined (selected).
If it does not exist in the specified type of PDL, an error is returned in each case in a normal case, and an appropriate breakdown (change of drawing command) is requested to the device interface processing unit (GDI.EXE) 12.

The PDL designation information is used to designate a specific PDL when it is desired to use the specific PDL. As the PDL designation information, "automatic selection" is designated in the normal case, but it is also possible to designate that a specific PDL is used with an emphasis on image quality and reproducibility. For example, when it is desired to express halftones beautifully, “PostScript” is designated as the type of PDL. In that case, when a specific PDL is designated, the automatic selection function is bypassed, and in the control processing of the DDI control unit 1, the print data is directly passed to the PDL conversion unit 2 of the corresponding PDL type. Become.

As described above, the data type determination unit 3 determines the data type by examining the ratio of the text, graphic and image of the received print data. That is, in determining the data type, the drawing command passed from the DDI control unit 1 can be classified into one of a text drawing command, a graphics drawing command, and an image drawing command. The data type is determined by examining the number of commands. As a result, the data type is classified into one of the following. (1). Text-only type, (2). Graphics-only type, (3). Image only type,
(4). Text and graphics only type,
(5). Type of text and image only (6). Graphics and image only type, (7). A type that includes all text, graphics and images.

The PDL capability table 6 shows how many drawing commands are used that cause image quality deterioration when the drawing commands from the device interface processing unit (GDI.EXE) 12 are replaced with the PDL drawing commands. Used to judge.

FIG. 3 is a diagram showing an example of the PDL capability table. As shown in FIG. 3, in the PDL capability table 6, each P
A device interface processing unit (GD
I. It is indicated whether or not each drawing command issued from the EXE) 12 can correspond to the drawing command of the PDL. Explaining in a specific example, in this case, when the drawing command issued by the device interface processing unit (GDI) is the curve drawing command “OutPut (ARC)”, “PDL # 1” of the first PDL. , The second P
DL "PDL # 2", third PDL "PDL #"
3 "is applicable, but the drawing command is" OutPut (ELLIPS) "which is an ellipse drawing command.
E) ”, the first PDL“ PDL #
1 "can be supported, but the second PDL" PDL "
Neither "# 2" nor "PDL # 3" of the third PDL is compatible. In addition, the drawing command is "O" of the circle drawing command.
utPut (CIRCLE) ”, the first PDL“ PDL # 1 ”and the second PDL“ P ”.
"DL # 2" is compatible, but "PDL # 3" of the third PDL is not compatible.

By referring to the PDL capability table 6 as described above, with respect to the current print data, the drawing commands issued from the device interface processing unit (GDI.EXE) 12 are converted into PDL drawing commands at a certain ratio. It can be determined whether or not it will be replaced.

Next, the PDL conversion time / transfer time database 7 will be described. FIG. 4 is a diagram for explaining the contents of the PDL conversion time / transfer time database 7. As shown in FIG. 4, the PDL conversion time / transfer time database 7 includes a document type field 7a, a PDL type field 7b,
It is composed of a PDL conversion time field 7c, a PDL data amount field 7d, and a sample number field 7e. As data of each field, according to the document type (data type), the PDL type PDL conversion time when PDL is used (Original 1
Each data of per MB and PDL data amount (per 1 MB of original) is stored together with the statistical data of the number of samples.

Explaining in a concrete example, the data (record data) in the first line of the PDL conversion time / transfer time database 7 is "document type is" text only "and PDL type is" PDL # 1 ". When PDL is used, its P
DL conversion time is "5 seconds" per 1MB of manuscript, and PD
The amount of L data is “1.2 MB” per 1 MB of the original. This data is obtained from the past 125 print data samples. ”

If the type of print data does not include graphics or images, or if the number of drawing commands that do not correspond directly is the same, the PDL capability table 6 is referred to and the PDL Since the type cannot be selected, statistical data (record data) stored in the PDL conversion time / transfer time database 7 is used for PDL conversion.
It is used to select the type of PDL that minimizes the sum of the conversion prediction time and the transfer prediction time.

The data content of the PDL conversion time / transfer time database 7 is created by the statistical data of past print data. As a result, the reliability is empirically increased from past statistical data, the PDL conversion prediction time and the transfer prediction time for print data are predicted, and the type of PDL having the smallest sum of these prediction times is selected. The predicted transfer time at this time is calculated by the following equation from the relationship between the transfer speed of the port to be output and the amount of PDL data. (Predicted transfer time) = (Predicted amount of PDL data generated) /
(Data Transfer Rate of Output Port) The automatic selection of PDL until the statistical data of the print data for all PDLs are complete is determined by, for example, the round robin method. As a result, data can be collected for all PDLs.

The data in the PDL conversion time / transfer time database 7 is updated every time the processing for the print request is completed. This means that the PDL will not be automatically selected and the data will be updated even if specified to use a particular PDL. The data is updated as follows. For statistics up to the present, P
The DL conversion time is A, the PDL data amount is B, the number of samples is n, the PDL conversion time is X, the PDL data amount is Y, and the statistics after the current print are set for the actual measurement value in this print. Regarding the values, if the PDL conversion time is A ', the PDL data amount is B', and the number of samples is n ', then A' = (A * n + X) / (n + 1) B '= (B * n + Y) / The statistical data (record data) in the PDL conversion time / transfer time database 7 is updated with (n + 1) n ′ = n + 1.

In this way, when outputting to a printer compatible with multi-PDL, statistical data from past print data is used to select a PD most suitable for print data.
Since the type of L can be selected and the drawing command by the selected PDL can be used to send to the printer, the PDL conversion time and the transfer time can be minimized while maintaining the maximum drawing quality.

That is, according to the printer driver of the present invention, the type of data passed to the printer driver is distinguished, the type of data to be identified is determined by the ratio of text, graphics, and image, and the graphics or image is determined. If it is included, the PDL capability table 6 is further referred to, and the drawing command that does not correspond directly is the smallest PD.
Select L. If no graphics or images are included, or if the number of drawing commands that do not correspond directly is the same, the past statistical data in the PDL conversion time / transfer time database 7 is referenced to predict the PDL conversion time. Then, the PDL that minimizes the sum of the predicted transfer times is selected. Then, the print data is converted into the drawing command by using the selected PDL command and sent to the printer. This makes it possible to minimize the PDL conversion time and the transfer time while maintaining the maximum drawing quality.

Next, with respect to the processing by the printer driver of the present embodiment configured as described above, the overall processing flow will be specifically described with reference to the processing flow. FIG.
6 is a flowchart showing a processing flow by a printer driver according to an embodiment of the present invention. In the printer driver process, when the process is started, first, in step 51,
Using the user setting information, the device interface "G
DI. The drawing ability is declared to "EXE." Next, in step 52, the device driver interface (DD
The print data is received according to I). Next Step 5
In 3, it is determined whether the PDL designation is “automatic selection”.

If the PDL designation is not "automatic selection", the type of PDL to be used for the print data is designated in advance by the user. Therefore, the process immediately proceeds to step 59, and the print data is PDL using the designated type of PDL. And send it to the printer. On the other hand, when the PDL designation is "automatic selection" in the determination of step 53, processing for determining the optimum PDL type from the characteristics of the print data is performed. Therefore, in the next step 54, the data type of the print data is determined and the print data is temporarily stored. Next, in step 55, it is determined whether or not the print data of which the data type is determined includes graphics or images. If the print data includes graphics or images, the process proceeds to the next step 56 and the PDL capability table is displayed. The number of drawing commands that are not directly corresponded is counted and the minimum PDL is selected. Then, in the next step 57, it is determined whether or not one PDL is determined by the selection. If the number of PDLs is not determined to be one, the process proceeds to the next step 58.

On the other hand, if it is determined in step 55 that graphics and images are not included, step 5
Proceed to 8. In step 58, the PD having the minimum sum of the PDL conversion prediction time and the transfer prediction time is referred to by referring to the statistical data.
Select L. As a result, the optimum PDL can be determined. Therefore, in the next step 59, the PDL selected here is selected.
With DL, the data to be printed is converted into PDL, transmitted to the printer, and the processing here ends.

By the way, in the above-described embodiment, when distinguishing the data type from the print data, the data type is set to "text only, graphics only,
There are seven types of "only images, only text and graphics, only text and images, only graphics and images, and all text, graphics and images." Even in the case of "graphics only", the optimum PDL to be selected may differ depending on the size of the graphics ratio.

For this, for example, PDL conversion time /
In the data of the transfer time database (7: FIG. 4), the content of the document reflects the print data type (data type) in more detail as the document type. FIG.
FIG. 9 is a diagram illustrating another example of a PDL conversion time / transfer time database. In this case, further considering the ratio between the number of text drawing commands and the number of graphics drawing commands in the drawing commands of the print data, as shown in FIG. Two types of record data are provided depending on the upper and lower sides of%. As a result, in addition to the effects of the above-described embodiment, it becomes possible to select a PDL that better matches the characteristics of the original.

A specific example will be described. As shown in FIG.
In the DL conversion time / transfer time database 70, "text and graphics only" (text less than 50%) and "text and graphics only (graphic Each record data is provided and the statistical data of the print data is updated according to the type of the document type.

As a result, even if the type of print data is "text and graphics only", if the graphics drawing command in it is 50% or more, the type of PDL is "PDL # 1". Then the PD
Statistical data that the L conversion time is “2 seconds” per 1 MB of the manuscript can be obtained. When the graphics drawing command is less than 50%, the PDL type is set to "PDL
If "1" is set, statistical data indicating that the PDL conversion time is "6 seconds" per 1 MB of the original document is obtained. By reflecting these statistical data in the PDL conversion time / transfer time database 70 and selecting the PDL by using such statistical data, it becomes possible to select the PDL more suited to the characteristics of the original.

Further, another modification will be described. In the above-described embodiment, when the document type is determined from the print data, the entire document is treated as one processing unit. Therefore, the first page is only the text and the second page is the image. In a 2-page document, the document type is determined to be a data type of "only text and image". Even if an attempt is made to select an appropriate PDL according to the criteria based on this judgment, the optimum P
In some cases, the DL type cannot be selected.

On the other hand, in the case where there are many documents in which the characteristics of the image of the print data are clearly separated for each page, a different type of PDL is used for each page. . As a result, more efficient print processing can be performed.

For this purpose, in the processing of the above-mentioned embodiment, it is only necessary to replace one document with a page. In this case, in the current print processing mechanism,
Since one document is one job, it is necessary to handle each page as a separate job. Therefore, if a banner (headline) sheet or the like is set for each job, the banner sheet is output every time the PDL is changed, so the banner sheet is not output. To do.

By the way, DPA (Document P
printing Application; ISO10
In the case of a printer according to 175), there is an option to handle a plurality of documents in one job. Therefore, in such a printer, even if each page is a separate document, the whole can be regarded as one job. Restrictions such as are relaxed.

As a result, when outputting to a multi-PDL printer, the PD most suitable for the printer data for each page
Since L can be used for transmission to the printer, it is possible to more efficiently minimize the PDL conversion time and transfer time while maintaining the maximum drawing quality.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of a printer driver according to an embodiment of the present invention,

FIG. 2 is a flowchart showing a series of operations of control processing by a printer driver,

FIG. 3 is a diagram showing an example of a PDL capability table,

FIG. 4 is a diagram for explaining a PDL conversion time / transfer time database;

FIG. 5 is a flowchart showing a processing flow by a printer driver according to an embodiment of the present invention,

FIG. 6 is a diagram illustrating a relationship between a personal computer and a printer,

FIG. 7 is a diagram for explaining the positioning of the printer driver,

FIG. 8 is a diagram illustrating a first example of conversion of a drawing command by a device interface processing unit,

FIG. 9 is a diagram illustrating a second example of conversion of a drawing command by the device interface processing unit;

FIG. 10 is a diagram for explaining another example of the PDL conversion time / transfer time database,

[Explanation of symbols]

1 ... Device driver interface control unit (DDI control unit), 2 ... Page description language command generation unit (PDL conversion unit), 3 ... Data type determination unit, 4 ... Temporary storage unit, 5 ...
Page description language selection unit (PDL selection unit), 6 ... Page description language capability table (PDL capability table), 7 ... PDL conversion time / data transfer time database, 8 ... Printer control unit, 9 ...
User setting information setting unit, 12 ... Device interface processing unit, 13 ... Printer driver, 14 ... Printer.

Claims (2)

[Claims] 1. A judgment means for judging characteristics of print data, and a selection for selecting an optimum kind of page description language among a plurality of kinds of page description languages which can be used by a printer to be controlled based on a judgment result of the judgment means. A printer driver, comprising: means for creating output data representing the print data in a selected type of page description language. 2. The printer driver according to claim 1, wherein the selecting unit selects an optimum page description language with reference to past output data creation time and transfer time of the output data to the printer. A printer driver characterized in that