JPH06183075A - Character processing device - Google Patents

Abstract

PURPOSE:To provide a character processing device with which use efficiency of a font cache memory can be improved largely. CONSTITUTION:An appearance frequency count means 100 counts previously the number of times of appearance of diagram data such as characters in a scheduled range of a document. A request frequency count means 200 reduces the number of times of appearance of the characters one by one at every print request and calculates remaining number of times of request of the diagram data such as the characters. A memory remaining quantity detect means 300 detects remaining quantity of memory of a font cache memory 500. A selection means 400 deletes selectively a dot data of a character whose remaining number of times of request is few from the font cache memory 500 when the memory remaining quantity detect means 300 detects shortage of the remaining quantity of memory.

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, the character data in the dot format which has been expanded once is registered in the font cache memory, and when the same character is used later, the data in the font cache memory is reused, A technique for outputting a document at high speed was developed. However, since the capacity of the font cache memory is limited, selection of characters to be registered in the font cache memory becomes a problem.

In order to solve such a problem, for example, in Japanese Unexamined Patent Publication No. 1-214449, the number of times of past access is stored for each character, and when the font cache memory becomes full, it is up to then. By making the object with the least access count to be deleted, the usage efficiency of the characters registered in the font cache memory is improved.

[0005]

The technique disclosed in the above publication is effective when each character appears uniformly over the entire document, but there are variations in the frequency of use of each character before and after the document. Then, unnecessary data may remain and useful data may be deleted.

That is, when the character A whose usage frequency is high in the latter half of the document and the character B whose usage frequency is high in the latter half of the document are compared, the character A starts to appear frequently. If the font cache memory becomes full before, the character A is deleted with priority over the character B, so that the character A that should be left is deleted, and there is a problem that the font cache memory cannot be effectively used.

An object of the present invention is to solve the above-mentioned problems of the prior art and to significantly improve the usage efficiency of the font cache memory even if the usage frequency of characters varies before and after the document. It is to provide a processing device.

[0008]

In order to achieve the above-mentioned object, in the present invention, in a character processing device equipped with a font cache memory for expanding and registering a vector font in a dot pattern, a predetermined range of a document is set. To target,
An appearance number counting means for counting the number of appearances of each character in advance,
Based on the number of appearances and the number of print requests, a request count counting unit that counts the remaining request count for each character, a memory remaining amount detection unit that detects the memory remaining amount of the font cache memory, and a memory remaining amount When it is less than, the means for selecting the dot data registered in the font cache memory based on the remaining number of requests is provided.

[0009]

The number of appearances counting means registers the number of appearances of each character within a certain range of the document for each character, and the request number counting means calculates the remaining number of requests in the actual printing operation for each character. To do. Therefore, the font cache memory can be efficiently used by preferentially deleting the remaining characters with a small request count from the font cache memory.

[0010]

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.

The appearance number counting means 100 counts the number of appearances of each graphic data such as characters in advance in a predetermined range of a document. The number-of-requests counting unit 200 subtracts the number of appearances of the character by 1 each time there is a print request, and calculates the number of remaining requests for graphic data such as each character.

The memory remaining amount detecting means 300 detects the memory remaining amount of the font cache memory 500. When the memory remaining amount detecting unit 300 detects that the memory remaining amount is insufficient, the sorting / selecting unit 400 stores the dot data of the character with the smaller number of remaining requests, in the font cache memory 500.
Selectively delete from.

FIG. 2 is a block diagram showing a hardware configuration of a character processing device (printer device) according to an embodiment of the present invention.

In the figure, the ROM 2 stores a program for controlling the overall operation of the character processing device, a program for controlling the font cache memory 8, a program for defining the operation of the printer immediately after the power is turned on, and the like. There is. The RAM 3 is used as a save area for the stack of the CPU 1.

The CPU 1 sends commands and image data to the printer engine 5 through the printer interface 4, and conversely, the printer engine 5 sends the internal state of the printer engine to the CPU 1 through the printer interface 4. The printer engine 5 actually prints the image data transmitted through the printer interface 4 on paper.

The CPU 1 has a host interface 7
Via the host workstation 6 to receive document data to be printed, print control commands, etc., and based on them, the vector format data stored in the vector font memory 9 is expanded into dot format data. The operation of forming a bitmap image for one page in the page memory 10 and sending it to the printer engine 5 is controlled.

Further, the CPU 1 has the sorting / selecting means 40.
0 and the remaining memory amount detecting means 300 also function.

Next, an example of the structure of the document data received by the CPU 1 from the host workstation 6 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. In FIG. 9, only the instructions related to the operation of the present invention are shown and the other instructions are omitted.

Next, the control operation of the font cache memory of the CPU 1 of the document processing apparatus will be described with reference to the flow charts shown in FIGS. 3, 4 and 5 and the document data shown in FIG.

In step S1 of FIG. 3, the CPU 1 first receives document data from the host workstation 6. The document data is saved in the free space of the page memory 10 or the RAM 3.

Next, the process proceeds to step S2, and the range for checking the used characters is set. For example, one page of document data is set as the range. This range may be set in any manner, but in this embodiment,
It is determined according to an instruction from the host workstation 6.

Now, assuming that the document data shown in FIG. 9 has been set by the range setting in step S2, a prescan process for determining the number of appearances of each character is executed in step S3. FIG. 4 is a flowchart showing the prescan processing.

In the prescan process, step S in FIG.
In step 11, one command is read from the specified range, and the position specifying command is input at the beginning.
The determination of 12 is negative, and in step S13, it is determined whether or not it is a font setting command. If this judgment is negative, it is judged in step S15 whether or not it is a character print command. In this embodiment, this determination also becomes negative, and the process returns to step S11 and the next one command is input.

As is apparent from FIG. 9, since the font setting command (12-po, Mincho type) is input this time, the determination in step S12 is negative and the process proceeds to step S13. This time, the determination in step S13 is affirmative, so the process proceeds to step S14, and the current font is updated.
That is, in this example, the current font is "12
It is set to "Ming Dynasty".

When the process of step S14 is completed, the process returns to step S11, and the next one command is input. In this example, a character print command (A) is input. Therefore, step S
The determinations in steps S12 and S13 following 11 are negative, and the determination in step S15 is affirmative and step S1.
Go to 6.

In step S16, it is judged whether or not the character-by-character counter is set. If not, the process proceeds to step S17, in which the current font "12-po, Mincho-tai" and the character code (A ), That is, a counter for each character is set, and this is initialized (= 1).

When the above processing is performed, step S is performed again.
Returning to step 11, the next one instruction is input. If an instruction other than the page print instruction, font setting instruction, and character print instruction is input, steps S12 and S1 are performed.
3 and S15 are both negative, and step S11
Then, the next command will be input.

When the font setting for the character code (i), which is the next character, is input in step S11, the current font "12 po, Mincho type" is set in step S14 by the same operation as described above. , And returns to step S11.

When the character print command (YES) is input in step S11, steps S12 and S13 are negative and S15 is affirmative, and the process proceeds to step S16. Since the counter for the character code (i) has not been set yet, the process proceeds to step S17, and the counter corresponding to the current font "12 po, Mincho type" and the character code (i) is set and initialized. (= 1).

Next, in step S11, when the font setting for the character code (U) which is the third character is input, the current font "13 po, Gothic font" is set in step S14, and step S17 Then, the counter corresponding to the current font "13 po, Gothic font" and the character code (U) is set, and this is initialized.

Next, in step S11, when a font setting command for the character code (A) which is the fourth character is input, in step S14 the current
Since the font "12 po, Mincho type" is set, and the determination in step S16 is affirmative this time, the value of the character counter for the character (A) is incremented to 2 in step S18.

When the above operation is repeated for one page of document data, the number of times (frequency) of each character appearing in the document data of the one page is counted for each character in the character counter.

When the page print command, which is the last command of the document data, is input in step S11, step S1
The determination of 2 is affirmative, and the process proceeds to step S4 of FIG.
The CPU 1 receives document data from the host workstation 6 and develops it 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 S1
At 9, one instruction is read. Step S2
At 0, S22 and S24, it is determined whether the read command is a page print command, a font setting command, or a character print command.

In the case of a page print command, step S2
When 0 is affirmed, the process proceeds to step S5 of the main routine. In the case of the font setting command, step S22 becomes affirmative and the process proceeds to step S23 to perform the operation of updating the current font.

Further, if the command is a character print command,
If step S24 is affirmative, the process proceeds to step S25,
The operation of searching the font cache memory 8 is performed using the character code and the current font as a key. On the other hand, if the command is other than the above three commands, the process proceeds to step S26, and the process in response to the command is executed.

When the CPU 1 reads the character print command, the font cache memory 8 is searched by the processing in step S25, and in step S27, it is determined whether or not the character is registered in the font cache memory 8. The decision is made.

When it is determined that the character is registered, the process proceeds to step S33, and the expanded character (bitmap image) already registered in the font cache memory is output to the page memory 10. In step S35, the value of the character-by-character counter for the output-processed character is decremented by 1.

When it is determined that the font cache memory 8 is not registered (NO at step S27), the process proceeds to step S28, and the remaining memory capacity of the font cache memory 8 is detected. If the remaining memory capacity is sufficient, the process proceeds to step S32,
The vector font is read from the vector font memory 9, developed into a bitmap image, and registered in the font cache memory 8. In step S33,
The expanded character is output to the page memory 10, and step S3
In 5, the value of the character counter for the processed character is 1
Can be reduced only.

In this way, character expansion and output proceed,
Thereafter, when it is determined in step S28 that the remaining memory capacity is insufficient and registration in the font cache memory 8 is impossible, in step S29, a count value smaller than the value of the character-by-character counter for the character developed this time. It is determined whether or not the character of, that is, the character of which the number of times of subsequent accesses is small is present in the font cache memory 8.

When it is determined in step S30 that there is one, the CPU 1 deletes the one having the smallest count value from the font cache memory 8 in step S31.

On the other hand, when it is determined that the character does not exist, the character is developed from the vector font and output to the page memory 10 in step S34.

When the above processing is completed, step S1 is executed again.
Returning to 9, the operation of reading the next instruction is performed. When the above operation is continuously repeated and the processing for one page of the document is completed, the determination in step S20 becomes affirmative, and the process proceeds to step S5 of the main routine.

In steps S5 and S6, the CPU 1 sends the bitmap image for one page from the page memory 10 to the printer engine 5 via the printer I / F 4. As a result, printing is executed.

As described above, according to the present embodiment, the number of appearances of each character is counted in advance, the count value is decremented each time the character is accessed, and the subsequent number of accesses is calculated. When there is no more, the memory capacity is secured by deleting those that are accessed less frequently in the future, so that the usage efficiency of the font cache memory 8 can be greatly improved.

Next, a second embodiment of the present invention will be described with reference to the flow charts of FIGS. 6, 7 and 8. In addition,
Since the same or equivalent processing is executed in the steps denoted by the same reference numerals as the above, the description thereof will be omitted.

In the above-described first embodiment, regardless of the kind of the appearance character, that is, the character counter,
Although the prescan and the expansion are repeated for each page, the present embodiment is characterized in that the range of the prescan is changed according to the set number of the character counter.

This embodiment is different from the first embodiment in that steps S70 to S72 (FIG. 7) and steps S39 and S are different.
40 (FIG. 8) has been added. Therefore, only steps SS70 to S72 and steps S39 and S40 will be described.

When the prescan is started, the page counter is initialized in step S70 in FIG.

Thereafter, when it is determined in step S12 that the read instruction is a page print instruction, the process proceeds to step S71, and the count value of the page counter is incremented. In step S72, it is determined whether or not the number of set character counters is small, and if it is determined that it is small, the process returns to step S11.

In this manner, the prescan proceeds, and if it is determined in step S72 that the number of character counters set is large, the process proceeds to step S4 of the main routine. As a result, the value of the page counter at this time is in the prescanned range.

When the expansion processing is executed, as shown in FIG. 8, when it is determined in step S20 that the read instruction is a page print instruction, in step S39, the page counter is counted. The value is decremented. In step S40, it is determined whether or not the count value of the page counter is zero, and the expansion process is continued until it becomes zero.

According to the present embodiment, after all the characters of the first page of the document received from the host workstation or the like are registered in the font cache memory, the number of character counters set is still small and the font cache memory has no space. If there is space, this free space can be assigned to the characters on the second page of the document. Therefore, the font cache memory can be used without leaving a vacant space, so that more effective use can be achieved.

[0056]

As is apparent from the above description, according to the present invention, the number of appearances of each character obtained by searching a certain range of a document and the number of appearances of each character when this range is actually processed. Since the character to be deleted from the font cache memory is determined based on the number of requests, there is an effect that the font cache memory can be used efficiently.

[Brief description of drawings]

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

FIG. 2 is a block diagram of a document processing apparatus that is an embodiment of the present invention.

FIG. 3 is a flowchart for explaining the operation of the first exemplary embodiment of the present invention.

FIG. 4 is a flowchart showing details of step S3 in the flowchart of FIG.

5 is a flowchart showing details of step S4 in the flowchart of FIG.

FIG. 6 is a flow chart for explaining the operation of the second embodiment of the present invention.

7 is a flowchart showing details of step S3a in the flowchart of FIG.

FIG. 8 is a flowchart showing details of step S4a in the flowchart of FIG.

FIG. 9 is a diagram showing an outline of document data.

[Explanation of symbols]

1 ... CPU, 2 ... ROM, 3 ... RAM, 4 ... Printer I
/ F, 5 ... Printer engine, 6 ... Host W / S, 7 ...
Host I / F, 8, 500 ... Font cache memory, 9 ... Vector font memory, 10 ... Page memory, 100 ... Appearance count counting means, 200 ... Request count counting means, 300 ... Memory remaining amount detecting means, 400 ... Sorting selection means

Claims (1)

[Claims] 1. A character processing device comprising a font cache memory for expanding and registering a vector font in a dot pattern, wherein unregistered data is expanded from the vector font and registered data is read from the font cache memory. Appearance number counting means for counting the number of appearances of each character in advance in a range, request number counting means for counting the remaining request number for each character based on the number of appearances and print request number, and a font cache memory A memory remaining amount detecting means for detecting the remaining memory amount, and when the remaining memory amount falls below a planned value, the dot data registered in the font cache memory is selected based on the counted number of remaining requests. A character processing device comprising: means for performing.