JP3094712B2 - Page description language processor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a page description language processing apparatus for processing and outputting a page description language program in which document data is described in a page description language (PDL).

[0002]

2. Description of the Related Art In recent years, printing apparatuses and display apparatuses having a page description language processing system have been used. There are multiple page description languages depending on the manufacturer (eg, US X).
erox “Interpress” (registered trademark),
Adobe "PostScript" (registered trademark) of the U.S.A., is divided into a plurality of types according to a page description language that also interprets a page description language processing output device.

As described above, many conventional page description language processing output devices are dedicated to processing only a single page description language. FIG. 9 is a diagram showing a schematic configuration of a conventional general page description language processing output device that processes only a single page description language, and FIG. 10 is a diagram showing a processing flow thereof. In such a conventional page description language processing output device, a page description language program, which is input data, is subjected to language interpretation for each instruction by a page description language processing unit. Performs language operations, sets parameters in the table for parameter setting instructions, builds graphics data for graphics construction instructions, and sets the above parameters and graphics data to the frame buffer for drawing instructions. The map drawing is performed, and when the page output command is issued, processing such as reading out from the frame buffer and transferring it to the output device is performed.

On the other hand, in a distributed environment using a network, many workstations and personal computers are connected, and it is determined which page description language these workstations and personal computers use to output print data. It depends on the type of station or personal computer, the operating system (OS) operating on it, and application programs. Therefore, in order to use the conventional page description language processing printing apparatus which targets only a single page description language in such an environment, the number of printing apparatuses required is equal to the number of required page description languages. there were.

[0005] As means for solving this problem, there are roughly two conventional systems which can be roughly classified. In the first conventional method, the storage area for the control program of the printing apparatus is exchangeable, and the control program corresponding to the download command from the host is downloaded before using the printing apparatus, so that one apparatus can use the control program. This is a method for realizing control of various systems (Japanese Patent Application Laid-Open No. Hei 1-204768, "Printer Device", Japanese Patent Application Laid-Open No. 2-140279, "Printer Device with Control Program Rewrite", and Japanese Patent Application Laid-Open No.
No. 20623, “Printer system”). In these methods, the operation of the printing apparatus is expressed by software for controlling printing, and the term page description language is not used. It seems that these conventional methods assume a relatively low-level language as a means for controlling printing, not a high-level language having a page concept such as a page description language.

As a second conventional method, there has been proposed a method in which a plurality of page description language processing systems are provided in a storage device, switching is performed according to input data, and a plurality of page description languages are processed (for example, a special method). Published Unexamined Japanese Patent Application No. Hei 4-128068 "Page description language processing printing apparatus"). According to this method, the page description language can be switched immediately.

[0007]

As described above, the first conventional method uses a relatively low-level language instead of a high-level language having a page concept such as a page description language as a means for controlling printing. It seems to be assumed. In the implementation of a low-level control program, the size of the control program itself is relatively small, so that the above-mentioned first conventional method may suffice. The processing system is a high-level language processing system, and it is difficult to apply the first conventional method when the size of the program is considerable. Therefore, when the page description language processing printing apparatus is similarly realized using the first conventional method, the download time generated every time the page description language is switched becomes an overhead, which is a practical problem.

In the second conventional method, the entire page description language processing system is simply switched, so that each page description language processing program must be stored in its entirety. Is required. In order to solve this problem, in the above-described conventional method, the control program of the printing apparatus is shared so that the entire page description language processing system does not need to be replaced. However, the control portion of the printing apparatus does not occupy a large proportion as compared with the entire page description language processing system, and the improvement of the capacity of the storage device cannot be greatly expected by this solution.

An object of the present invention is to overcome the above-mentioned problems of the prior art. That is, an object of the present invention is to provide a page description language processing apparatus capable of supporting a plurality of types of page description languages, to make the system compact and to reduce the storage area required for processing. .

[0010]

A page description language processing apparatus according to the present invention (claim 1) interprets document data described in a page description language, that is, a page description language program, and converts it into intermediate language format data. A plurality of types of unique page description language processing means (12 in FIG. 1) and a common page description language processing means (13 in FIG. 1) for converting the data in the intermediate language format into abstract graphic data independent of the characteristics of the output device.
And output processing means (14 in FIG. 1) for creating image data to be output based on the abstract graphic data.

According to a second aspect of the present invention, in the page description language processing apparatus, at least one type of the specific page description language processing unit of the plurality of types of specific page description language processing units includes a storage unit of its own device or It is obtained by reading and executing a unique page description language processing program stored in a storage means on a network connected to the own device.

[0012]

The input data described in a certain page description language is selectively input to a unique page description language processing means corresponding to the page description language. The unique page description language processing means performs processing unique to each page description language by interpreting the input data, and converts the data into intermediate language format data that can be processed by the common page description language processing means. The data in the intermediate language format is data represented in a certain format in order to perform a process common to the plurality of types of page description languages.

The common page description language processing means processes the data in the intermediate language format to generate abstract graphic data. The abstract graphic data referred to here is data representing a drawing method of a graphic represented by a combination (combination) and a parameter pair of graphic elements independent of the characteristics and types of the output device.
This includes character fonts.

The processing functions of the common page description language processing means include, for example, an interface function with a specific page description language processing unit, a language support function enabling various operations, a graphics operation function, and the like. Includes functions that enable common processing.

The output processing means creates image data to be output, which is developed into a bitmap according to the characteristics of the output device based on the abstract graphic data.

According to the present invention, processing dependent on a specific page description language is separated from the page description language processing system, processed by the unique page description language processing means, and processing that can be standardized is described as one common page description. Since processing is performed by the language processing means, the configuration of the entire system can be made compact. In addition, correspondence to a new page description language can be performed only by describing a processing program used as a unique page description language processing unit in accordance with the specification of the corresponding page description language. Since the entire program does not need to be re-described, development is efficient, and even if a variety of page description languages are supported, an increase in the capacity of a storage area required to store a processing program is small.

When switching of the page description language does not occur frequently or when there is a page description language that is not frequently used, a page description language processing program for the specific page description language processing means is provided in the output device. Alternatively, the capacity of the storage device of the page description language processing apparatus can be reduced by using the program by downloading it from the outside via a network as needed.

[0018]

FIG. 1 is a functional block diagram of a page description language processing printing apparatus according to an embodiment of the present invention. This device is
An input data processing unit 11, a unique page description language processing unit (all "PDL" in the drawings is abbreviated to "page description language") 12, a common page description language processing unit 13, and an output processing unit 14 And

The input data processing unit 11 reads the input data and sends it to the corresponding unique page description language processing unit 12. At the start of the process, the corresponding page description language processing system is selected and registered in the page description language processing unit 12. At this time, if it is necessary to download from a local host and a host connected on the network, the download operation is also performed.

The unique page description language processing section 12 interprets input data described in a certain page description language, generates data in an intermediate language format common to each page description language,
It is output to the common page description language processing unit 13.

The common page description language processing unit 13 defines a common operation of commands such as graphics and language operation of each page description language as an interface, operates according to a command from the unique page description language processing unit 12, and internally. When a graphics image is formed and finally an output command is received from the specific page description language processing unit 12, the graphics image is output to the output processing unit 14.

The output processing section 14 receives the graphics output command from the common page description language processing section 13, forms an output image of a bitmap in the frame memory of the printing apparatus, and performs printing.

FIG. 2 schematically shows a hardware configuration for realizing the above functions. This device includes an input device 21, a central processing unit 22, a storage device 23, and an output device 24.

The input device 21 is a receiving device for input data,
It has a buffer and the like. When connected to the network 25, an access device to the network 25 is also included. This input device functions when the central processing unit 22 executes the input processing program stored in the storage device 23.

The central processing unit 22 is a device that executes various programs stored in the storage device 23, and the functions of this embodiment shown in FIG. Further, the input device and the output device are driven according to the program.

The storage device 23 stores programs such as an input process, an output process, a unique page description language process, and a common page description language process, and stores them in a work area, a graphics image, and a frame memory of a printing device when the program is executed. Used. Among them, a plurality of unique page description language processing programs are stored in the storage device 23, and are used by being switched by the programs. When the capacity of the storage device 23 is limited, the configuration can be switched by downloading from the destination connected to the input device 21.

The output device 24 is a device for outputting an image formed by executing a program. This device is generally a printing device such as a laser beam printer,
It can be used for other output devices such as a graphics display.

The operation of the page description language processing output device of the embodiment configured as described above will be described. FIG.
It shows the flow of the processing.

When the input data processing unit 11 receives a specific page description language program as input data, it first determines which page description language the data is described in. In a page description language program of PostScript of Adobe in the United States or Interpress of Xerox in the United States of America, an annotation is attached to the head of the data and the language name of the language, for example, "%! PS-Ado
be-1.0 "or" Interpress / Xero
Since it is customary to describe such as “x”, it is possible to judge from this annotation (procedure 1).

If there is a page description language specification or host-side client software for which the above method cannot be realized, a method of explicitly switching in advance is necessary, and this method is prepared (procedure 1). ').

When the input data processing unit 11 detects the corresponding page description language using the above or other means, it registers the corresponding unique page description language processing program from the storage device 13 into the page description language processing system ( Procedure 2).

If there is no corresponding page description language processing program in the storage unit 13, the input data processing unit 11 is connected to the host to which the printing apparatus is connected or is connected to the network when the network is connected. It is also possible to make an inquiry to the host, and if found, to perform a download process (procedure 2 ').

In this case, the input processing unit 11 is searching for a unique page description language processing program, but the input processing unit 11 does not have such a function, and a download operation is previously performed from a host or a server on a network. (Procedure 2 '').

After the specific page description language processing unit 12 is established as described above, the input data processing unit 11 sequentially passes the input data to the specific page description language processing unit 12 (step 3).

Upon receiving data from the input data processing unit 11, the unique page description language processing unit 12 executes instructions one by one while checking for errors (procedure 4). The execution here refers to interpreting the command, performing processing, translating into a common page description language processing command independent of the page description language, and outputting the same.

The common page description language processing command is processing such as graphics operations, stacks, and dictionaries specific to the page description language. Processing specific to the page description language includes combining simple figures (straight lines, arcs), etc., constructing complex figures, and then filling, deforming, and coloring them. Redefine instructions, store key and data combinations in a dictionary,
This is processing for searching from a key. The common page description language processing unit 13 commonizes these processes between page description languages, and uses the unique page description language processing unit 1 as an interface.
2 is provided. Then, internally, these special commands are decomposed into general simple graphics drawing commands and various drawing parameters, and the data is passed to the output processing unit 14 (procedure 5).

The output processing unit 14 forms an output image from the simplified graphics drawing command and drawing parameters, and draws a bitmap in the frame memory of the output device. Font drawing is also included in the graphics drawing command. Printing devices and display devices are handled in the same manner as output devices (procedure 6).

Next, as for the common page description language processing unit 13 for executing the above-described procedure 5, a case where two page description languages, PostScript and Interpress, are used as page description languages will be taken as an example. How to implement the description language processing will be described in more detail. The common page description language processing unit 13 is roughly divided into three modules according to its functions: (1) interface, (2) language support, and (3) graphics operation.

(1) Interface Module This interface module is a group of functions directly called from the unique page description language processing unit 12, and mainly converts them into functions of each module of language support or graphics operation. Function. The data used for this function interface has an abstracted data structure and hides the data type. This is a feature of the page description language. Therefore, various data (numerical values, graphics, fonts, etc.) can be handled in common for one operation command. For this reason, for example, copying can be performed with one copy command, and all types of data can be copied.

(2) Language Support Module As described in (1), all kinds of data are handled as abstract data (objects). A language support module provides various operations to these objects. The commands processed by the language support module are shown below.

(2.1) Object creation instruction Empty object creation instruction Object creation is a model in which an empty object is first created by an empty object creation instruction, and then this empty object is changed to another type of object (instantiation). Take. Therefore, all objects have various types by changing the object generated by the empty object generation instruction.

Simple Object Generation Instruction A simple object has a C language variable value itself as an instance variable.

Composite Object Generation Instruction A composite object has an object as an instance variable.

Operator-type Object Generation Instruction The operator-type object has a pointer to a function as an instance variable. That is, it expands the procedure represented by the name (character string) into the actual function represented by the name, and directly has a pointer to the function.

(2.2) Object Copy and Delete Instructions There are the following three types of object copy. Simply duplicate the object with every instance variable.

If the instance variable of the object is an object, the object is also duplicated.

In the preceding paragraph, replication is performed recursively, following instance variables of all objects.

Deleting an object is not merely a matter of deleting the object. If the object is referenced by another object, it cannot be deleted. Similarly, if the object referred to by the object is not referred to by another, the object is deleted, and if the object is referred to, the object is not deleted.

(2.3) Operation Commands Operations on objects are roughly divided into the following three.

Reading the value of an instance variable of an object The instance variable of a simple object is read as a variable value for a client to perform an arithmetic operation or the like.

Change of an object that an object has as an element (instance variable)

Extraction of the number of elements of an object that the object has as elements (instance variables)

(2.4) Stack Instruction The stack provided by the common page description language processing unit 13 is a stack with no limitation in depth. However, there is a limit depending on the amount of installed memory. This stack contains:
Objects can be stored.

The arguments of the stack operation are all objects. Specifically, a stack, a stack index, a storage (retrieving) object, and a storage (retrieving)
There are four of the number of objects.

The operations include generation of a stack, storage (Push) of the top-level object, extraction (pop), exchange (exch), duplication, modification, and modification of the number of objects indicated from the indicated index. Change order (r
oll), the number of elements stacked on the stack.

(2.5) File operation instructions Provide instructions for opening, closing, reading, and writing files. A file is a standard input / output destination. Reading is performed using a method of changing an empty object to a character string object. Both the read (write) destination and the read (write) length of the argument are objects.

(2.6) Utility (utili)
ty) In addition to the above, the following three functions are provided. Read object instance variables Object type (integer, real, dictionary, etc.), at
Returns a tribute value and a referenced value. The referenced value is a value indicating whether the object is referenced by another object.

Type Checking The following three types of type checking instructions are provided.

A) Check whether the object corresponds to the object defined in the common page description language processing interface.

B) Checking the type of simple, semi-composite or composite object.

C) An inquiry as to whether the object type is a specified one.

Error Inquiry An error state generated when the instruction is executed is confirmed.

(2.7) Save and restore instructions This is a module for managing save and restore of objects. Only certain types of objects have save and restore instructions.
A function to restore and a function to save and restore only specified objects are provided.

(3) Graphics Operation Module Graphics operation consists of four functions: graphics parameter setting command, graphics data construction command, graphics drawing command, and page output command.

The graphics include line figures, characters, images, and the like. Here, a detailed example will be given, particularly for a diagram system.

The graphics parameter setting process is a graphics drawing parameter setting process. The parameter is data that specifies attributes for drawing, such as a coordinate system, line width, end point shape, and color. FIG. 4 shows an example of the graphics parameter, showing the parameter name and the meaning of the value. This parameter is used as an additional parameter when executing the rendering command. FIG. 5 shows an example of graphics, and illustrates what parameters are set in the figure.

The processing of the graphics data construction instruction is a processing peculiar to the page description language, and is for constructing a combination graphics by combining graphics primitives. That is, a complicated figure is constructed by combining a number of simple figures (straight lines, arcs) and the like. Fonts are treated the same as graphics. This operation is not performed in a format that depends on the output device, but is performed in a format that does not depend on the output device in the coordinate system.

The basic primitive is named segment, and a collection of several segments is called subpa.
th and further collected are named path. In the example of FIG. 6, LineSegment and ConicSg
In this case, Subpath1 is configured by combining the two Line Segments, and S is combined by combining four Line Segments.
ubpath2 is constructed, and these two Subpa
The path is configured by combining th. The segment, subpath, and path have a hierarchical structure as shown in FIG. 7, and are managed by a data structure as shown in FIG.

The path has various attributes. As attributes for indicating the closed area, OPEN, CLOSE (Eve
n-Odd) and CLOSE (Non-Zero).

There is a REVERSE attribute to indicate the connection direction of subpath and segment. REVE
In the RSE state, the fulcrum and the end point of the graphics are reversed, and the coordinates in the segment follow upside down.

The attribute of subpath is an attribute for indicating whether or not it is explicitly closed, and OPEN, CLOSE
There is. POIN as the line type attribute of each segment
There are T, LINE, CONIC, ARC, and BEZIER.

The processing of the graphics data drawing command is sent to the output processing unit 14 as a simple graphics command by combining the additional parameters with the path constructed in the above processing.

In the processing of the page output command, the output processing unit 14 is instructed to perform the output processing.

According to this embodiment, the following advantages can be obtained. (1) This embodiment separates a process that depends on a specific page description language from a page description language processing system,
Correspondence to a new page description language can be performed only by describing the specific page description language processing part according to the specification of the relevant page description language. Since it is not necessary to re-describe the whole, development is efficient, and even if the printer supports a plurality of page description languages, the increase in the capacity of the storage area required by the entire printing apparatus is small.

(2) When there are many types of page description languages to be handled or when the capacity of the storage device is limited,
By storing the unique page description language processing portion on a network or the like and downloading it as needed, it is possible to construct a printing apparatus in which the number of page description languages that can be handled is not restricted by the storage capacity.

[0076]

According to the present invention, a process which depends on a specific page description language is separated from a page description language processing system and processed by a unique page description language processing means, and a process which can be standardized is one common process. Since the processing is performed by the page description language processing means, the configuration of the entire system can be made compact. In addition, correspondence to a new page description language can be performed only by describing a processing program used as a unique page description language processing unit in accordance with the specification of the corresponding page description language. Since it is not necessary to re-describe the entire program, development is efficient, and even if a variety of page description languages are supported, an increase in the capacity of a storage area required to store a processing program is small.

When the switching of the page description languages does not occur frequently or when there is a page description language that is not frequently used, a page description language processing program for the specific page description language processing means is provided in the output device. Alternatively, the capacity of the storage device of the page description language processing apparatus can be reduced by using the program by downloading it from the outside via a network as needed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram schematically illustrating an example of a hardware configuration according to an embodiment;

FIG. 3 is a diagram showing a processing flow of an embodiment.

FIG. 4 is a diagram showing examples of graphics parameters.

FIG. 5 is a diagram showing an example representing a relationship between abstract graphics data and graphics parameters.

FIG. 6 is a diagram for explaining the concept of abstract graphics

FIG. 7 is a diagram illustrating an example of a hierarchy of abstract graphics.

FIG. 8 is a diagram showing an example of the data structure of Path.

FIG. 9 is a diagram showing a schematic configuration of a conventional page description language processing output device.

FIG. 10 is a diagram showing a processing flow of a conventional page description language processing output device.

[Explanation of symbols]

11: input data processing unit, 12: specific page description language (PDL) processing unit, 13: common page description language processing unit,
14 Output processing unit.

Claims (2)

(57) [Claims] 1. A plurality of types of unique page description language processing means for interpreting document data described in a page description language and converting the document data into data in an intermediate language format, and converting the data in the intermediate language format into characteristics of an output device. A page description language processing apparatus, comprising: a common page description language processing means for performing conversion processing to abstract graphic data that does not depend on the image data; and an output processing means for generating image data to be output based on the abstract graphic data. 2. The page description language processing device according to claim 1, wherein at least one kind of unique page description language processing means of said plurality of kinds of unique page description language processing means is provided in its own storage means or its own apparatus. A page description language processing apparatus obtained by reading and executing a unique page description language processing program stored in storage means on a connected network.