JPH06183076A - Character processing device - Google Patents

Abstract

PURPOSE:To largely improve use efficiency of a font cache memory. CONSTITUTION:Image data forming sections 3A and 3B receive code data from a host computer 1, read out vector data corresponding thereto from a vector font memory 6, develop it into bit image, and register respectively in local font cache memories. 8A and 8B. A font cache memory controller 11 extracts dot data of a scheduled character (global character) from the local font cache memories 8A and 8B and registers it in a global font cache memory 7 and deletes the dot data from the local font cache memories 8A and 8B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character processing device, and more particularly, to a character cache device for expanding graphic data (vector font) of characters or the like expressed in vector format into dot format data and registering the data. It relates to a character processing device.

[0002]

2. Description of the Related Art Using character data represented in a vector format has an advantage that high quality characters can be obtained, but on the other hand, there is a problem that it takes time to develop the character data in dot format.

In order to solve this problem, once expanded dot format character data is registered in the font cache memory, and when the same character is used later, the data in the font cache memory is reused for high speed. A technique of outputting a document to was developed. However, since the storage area of the font cache memory is limited, it is necessary to replace unused dot data by storing new dot data.

Conventionally, methods such as the FIFO method and the LRU method are generally used to determine which dot data is not required.

The FIFO (First in First Out) type font cache is a system in which the oldest one stored in the font cache memory is flushed first.

[0006] On the other hand, the LRU (Least Recentry Used) font cache is a method in which, of the fonts stored in the font cache memory, the one with the oldest used time is ejected first.

By the way, recent character processing devices (laser printers, etc.) are equipped with a plurality of image processing units (image data forming units) for developing vector fonts corresponding to code data to form image data consisting of dot data. is doing. However, in the character processing device having such a configuration, the quality of the printed characters is greatly different due to the superiority or inferiority of the performance of each image processing unit.

In order to solve such a problem, for example, Japanese Patent Application Laid-Open No. 2-202461 discloses a technique for solving this problem by allowing a common font cache memory to be used by each image processing unit. There is.

[0009]

However, in the above-mentioned conventional technique, a character (local character) frequently used by only one image data forming unit causes a character or both used by only the other image data forming unit. The shared character (global character) is pushed out from the font cache memory, and there is a problem that the usage efficiency of the font cache memory is low.

SUMMARY OF THE INVENTION An object of the present invention is to provide a character processing device which solves the above-mentioned problems of the prior art and can greatly improve the usage efficiency of the font cache memory.

[0011]

In order to achieve the above-mentioned object, according to the present invention, there are provided a first and a second expanding means for expanding a vector font into dot data, and a first and a second expanding means. The first and second font cache memories that store the generated dot data (local characters), and the planned dot data (global characters) from the first and second font cache memories.
Is selectively extracted and deleted from each font cache memory, and a third font cache memory for storing the extracted dot data (global character) is characterized.

[0012]

In the above configuration, for example, if local characters registered in both the first and second font cache memories are registered as global characters in the third font cache memory, the first expansion means is provided. Local characters used only by the first font cache memory are registered, local characters used only by the second expanding means are registered in the second font cache memory, and global characters used by both are the third character. It is registered in the font cache memory.

Therefore, for example, even if the number of local characters used only by the first expanding means is increased, the local characters used by only the second expanding means and the first and second characters are thereby increased.
It is possible to prevent the global characters used by any of the expansion means from being expelled from the font cache memory.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram for explaining the function of the present invention.

Character data is stored in the vector font memory 6 in a vector format (vector font). The image data forming units 3A and 3B use the host computer 1 to input the codes of characters to be printed and print control commands.
From the vector font memory 6 to read the vector font corresponding to the character code from the vector font memory 6, develop it into dot data, and register it in the local font cache memories 8A and 8B, respectively.

Further, the image data forming sections 3A, 3B
Forms a page of bitmap image in the page memory 5 and sends it to the printer engine 12 via the video interface 11. Printer engine 1
2 prints the image data sent from the page memory 5 on a recording sheet.

The font cache memory control unit 10 is
The dot data of a predetermined character (global character) is extracted from the local font cache memories 8A and 8B and registered in the global font cache memory 7, and the dot data is deleted from each of the local font cache memories 8A and 8B.

Next, an example of the structure of the document data received by the image data forming sections 3A and 3B from the host computer 1 will be described with reference to FIG.

The structure of one page of document data is made up of a position designation command, a command for each character of the document, a page print command, and the like. The position command command is a command for instructing the print position of the first character of the document. The commands for each of the characters include a font setting command, a character printing command, and the like. The page print command is provided at the end of each page of document data. It should be noted that FIG. 3 shows only the instructions related to the operation of the present invention, and the description of other instructions is omitted.

Next, the operation of this embodiment will be described in detail with reference to the flowcharts shown in FIGS. 2, 4, and 5 and the document data shown in FIG.

In step S1 of FIG. 2, the image data forming unit 3A first receives document data from the host computer 1. The document data is stored in the RAM area provided in the image data forming unit 3A.

Next, in step S2, the image data forming unit 3A executes a process of developing the document data into a bitmap image. An example of the expansion processing will be described with reference to the flowchart of FIG.

When the expansion process starts, step S in FIG.
One instruction is read in 202 and the position designation instruction is input at first, so the determination in step S203 is negative, and in step S205, it is determined whether or not it is a font setting instruction.

If this judgment is negative, step S20
At 7, it is determined whether the command is a character print command. In the present embodiment, this determination also becomes negative, the process proceeds to step S209 to execute the process in response to the command, and then returns to step S202 to input the next one command.

As is apparent from FIG. 3, since the font setting command (12 po, Mincho type) is input this time, the determination in step S203 becomes negative and step S205.
Go to. This time, the determination in step S205 is affirmative, so the flow advances to step S206 to update the current font. That is, in this example, the current font is set to "12-po, Mincho-type."

When the process of step S206 is completed, the process returns to step S202 again, and the next one command is input. In this example, a character print command (A) is input. Therefore, the determinations of steps S203 and S205 following step S202 are negative, and the determination of step S207 is affirmative, and the process proceeds to step S208.

In step S208, the global font cache memory (hereinafter sometimes referred to as GFCM) using the current font and character code as keys.
7 is searched, and in step S210, it is determined whether or not the dot data relating to the character is registered in the GFCM 7. If registered, step S218
At, the dot data is output from the GFCM 7 to the page memory 5.

On the other hand, if not registered, step S2
In 11, the local font cache memory (hereinafter referred to as LFC) using the current font and character code as keys.
8A is searched.

In step S212, the LFCM8A
If it is determined that it is not registered in step S213,
Then, it is determined whether registration is possible in the LFCM 8A. If registration is not possible, in step S214, the dot data registered in the LFCM 8A by the LRU method is deleted.

If it is determined in step S213 that the character can be registered, in step S215 the vector font of the character is expanded into dot data and LF is added.
Registered in CM8A. In step S216, the font cache memory control unit 10 is activated, and after that, as shown in FIG.
The processing described with respect to is executed. Step S217
Then, the dot data obtained by the expansion is output from the LFCM 8A to the page memory 5.

After that, when the page print command is read, step S203 becomes affirmative and the process proceeds to step S3 of the main routine. In steps S3 and S4, the image data forming unit 3A sends the bitmap image for one page from the page memory 5 to the printer engine 12 via the video interface 11, and printing on recording paper is executed.

In the above, the image data forming section 3A
However, the operation of the image data forming unit 3B is almost the same except that the local font cache memory 8B is to be searched and registered. Therefore, the description thereof will be omitted.

FIG. 5 is a flow chart showing the operation of the font cache memory control unit 10 started in step S216.

In step S1002, it is determined in which LFCM the dot data is registered, and the LFCM is determined.
8A, steps S1003 to S1008 are registered.
When the process is executed and registered in the LFCM 8B, the processes of steps S2003 to S2008 are executed. Since the processing of steps S1003 to S1008 and the processing of steps S2003 to S2008 are almost the same, only the processing of steps S1003 to S1008 will be described here.

In step S1003, the LFCM 8B is searched using the character registered in the LFCM 8A as a key. In step S1004, the character is LFCM.
If it is determined that it is registered in 8B, step S10.
In 05, it is determined whether the character can be registered in GFCM7.

If registration is not possible, dot data is selectively deleted from the GFCM 7 by the LRU method in step S1006, and if registration becomes possible, step S1006 is performed.
Registered with GFCM7 at 1007.

In step S1008, the characters registered in GFCM7 are deleted from LFCM8A and LFCM8B.

As described above, according to the present embodiment, the characters (global characters) shared by the image data forming units 3A and 3B are the common global font cache memory 7.
The characters (local characters) registered in the image data forming units 3A and 3B are registered only in the separate local font cache memories 8A and 8B, so that only one image data forming unit is frequently used. The characters that are used by the other image data forming unit are prevented from being expelled from the font cache memory by the characters used by only the other image data forming unit or the characters used by both of them.

FIGS. 6, 7 and 8 are flow charts for explaining the operation of the second embodiment of the present invention.

In the first embodiment described above, only the characters registered in the respective image data forming sections 3A and 3B are GFC.
Although it has been described that it is registered in M7, in this embodiment, G
The feature is that the condition to be registered in the FCM 7 can be selected.

As in the case of the first embodiment, the font cache memory controller 10 in step S216.
When is activated, the operation mode is determined in steps S62 and S64.

Here, as in the case of the first embodiment,
When the "neutral mode" in which only the characters registered in both the image data forming units 3A and 3B are registered in the GFCM 7 is selected, the process proceeds to step S63, and steps S1002 to S1015 described with reference to FIG. The process is executed.

On the other hand, if the "A mode" for registering at least the characters registered in the LFCM 8A in the GFCM 7 is selected, the process proceeds to step S65, and the "B mode" for registering at least the characters registered in the LFCM 8B in the GFCM 7 is selected. Then, the process proceeds to step S66.

FIG. 7 is a flow chart showing the operation of the font cache memory controller 10 when the A mode is selected, which is executed in step S65.

In step S6502, which LFC
It is determined whether a character is registered in M, and if it is registered in LFCM 8B, the process ends.

If registered in the LFCM 8A, in step S6503 the LFCM 8B is searched using the character registered in the LFCM 8A as a key.

In step S6504, the LFCM8
If it is determined that it is registered in B, step S650.
In 8, the character is deleted from the LFCM 8B.

In step S6505, the character is set to GF.
It is determined whether the CM 7 can be registered. If registration is not possible, then in step S6506 the GF is sent using the LRU
When the character is selectively deleted from the CM 7 and can be registered, the character is registered in the GFCM 7 in step S6507.

In step S6509, the character registered in GFCM7 is deleted from LFCM8A.

FIG. 8 is a flow chart showing the operation of the font cache memory control unit 10 when the B mode is selected, which is executed in step S66, and this operation can be easily understood from the operation of FIG. , The description is omitted.

According to the present embodiment, the registration condition in the GFCM 7 can be made different by selecting the operation mode. Therefore, by selecting the operation mode according to the usage status of the device, the font cache memory The use efficiency can be further improved.

[0052]

As described above, according to the present invention, local characters used only by one image data forming unit are registered in one local font cache memory,
Local characters used only by the other image data forming unit are registered in the other local font cache memory, and global characters used by both are registered in the global font cache memory. Therefore, for example, even if the number of local characters used only by one image data forming unit increases, the local character used only by the other image data forming unit and the global character used by each image data forming unit are not changed in the font cache. It is prevented from being evicted from the memory.

[Brief description of drawings]

FIG. 1 is a functional block diagram of the present invention.

FIG. 2 is a flowchart showing the operation of the first exemplary embodiment of the present invention.

FIG. 3 is a diagram showing an outline of document data.

FIG. 4 is a flowchart showing details of step S2 in FIG.

FIG. 5 is a flowchart of a process activated in step S216 of FIG.

FIG. 6 is a flowchart showing the operation of the second exemplary embodiment of the present invention.

FIG. 7 is a flowchart showing details of step S65 in FIG.

FIG. 8 is a flowchart showing details of step S66 in FIG.

[Explanation of symbols]

1 ... Host computer, 2 ... Host interface,
3 ... A, 3B image data forming unit, 5 ... page memory, 6 ... vector font memory, 7 ... global font cache memory, 8A, 8B ... local font cache memory, 10 ... font cache memory control unit, 11 ... video interface, 12 ... printer engine,

Claims (1)

[Claims] 1. A character processing device comprising a font cache memory for expanding and registering a vector font into dot data, wherein unregistered data is expanded from the vector font and registered data is read from the font cache memory. First and second rasterizing means for rasterizing the data, first and second font cache memories for storing the dot data obtained by the first and second rasterizing means, respectively. It is provided with a control means for selectively extracting predetermined dot data from the font cache memory and deleting it from each font cache memory, and a third font cache memory for storing the extracted dot data. Character processing device.