JP2972211B2 - Character output control device and method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a character output control device and method for generating and outputting a character / symbol pattern.

2. Description of the Related Art Usually, most printing devices or display devices have a font memory storing an N × M dot pattern corresponding to a character code, and can store a character pattern based on an input character code. The image is formed by printing out or displaying the generated character pattern.

By the way, in recent years, a high definition of a formed image is desired for an image forming apparatus. Accordingly, the dot density of the character pattern must be increased, and the capacity of the font memory is required to be enormous.

On the other hand, there is also a demand for forming character images of different sizes. One method for solving this problem is to make one pixel of the basic N × M dot character pattern correspond to, for example, 2 × 2 pixels. However, this still has a problem because roughness is conspicuous. .

Therefore, in recent years, an English text printing apparatus that uses a method of storing a character shape as an aggregate of vector information instead of storing a character pattern itself in a memory has appeared. In this printing process, first, all characters are temporarily converted from vector information into a character pattern, and the character pattern is registered in a RAM or the like. Hereinafter, when an image corresponding to the input character code is formed, a process of reading out and outputting a corresponding character pattern from the memory is performed. Since this eliminates the process of generating a character pattern corresponding to each character code, throughput such as a microprocessor can be provided.

[Problems to be Solved by the Invention] However, if this method is applied to a Japanese printing apparatus as it is, the total number of characters (including special symbols) in Japanese is enormous, and the generated character pattern is stored. A huge amount of memory is required. This is practically impossible in terms of memory efficiency and cost.

The present invention has been made in view of such a problem, and controls a cache memory that stores dot data created from non-dot data based on the counted frequency information, so that the cache memory can be dynamically and efficiently stored. It is an object of the present invention to provide a character output control device and method which can be used well.

[Means for Solving the Problems] To solve the problems, for example, a character output control device of the present invention has the following configuration. That is, a character output control device that reads non-dot data corresponding to a character code input from the outside from predetermined storage means, creates dot data, and outputs the dot data at an output unit, wherein the frequency of the input character code is Counting means for counting, a cache memory for storing the created dot data, and control means for controlling the cache memory based on the frequency counted by the counting means.

Embodiment An embodiment according to the present invention will be described below in detail with reference to the accompanying drawings.

<Description of Schematic Configuration (FIG. 1)> FIG. 1 shows the relationship between a host computer 1 serving as a data source and a printing device 2 in the embodiment, and the printing device 2 in the embodiment.
The block diagram of FIG.

In the figure, reference numeral 21 denotes a control unit for controlling the entire printing apparatus,
It comprises a CPU 21a, a ROM 21b storing the processing procedure thereof, and a RAM 21c used as a work area.
The ROM 21b stores programs relating to the flowcharts shown in FIGS. 5 and 6 described later.

A vector font storage unit 22 stores vector information corresponding to various character codes, and a vector / dot conversion unit 23 converts the read vector information into a dot character pattern. Reference numeral 24 denotes a font cache memory, the details of which will be described later. 25 is a management table memory for managing the frequency of each character code received from the host computer 1, 26 is a frame buffer for expanding the output character pattern image, and 27 is data for expanding the frame buffer 26. A printer unit for outputting to printing paper, and 28 is a non-volatile memory.

<Explanation of Outline of Print Processing FIGS. 2 to 4)> The outline of the print processing in the present embodiment is as follows.

First, when the power of the printing apparatus in the present embodiment is turned on, the CPU 21a transfers the contents of the nonvolatile memory 28 to the management table memory 25. The non-volatile memory 28 stores frequency information of characters printed in the past for all character codes. In the embodiment, the size of the data representing the frequency is set to 2 bits (hereinafter simply referred to as frequency information).

Thereafter, the CPU 21a refers to the contents of the management table memory 25 and stores the pattern corresponding to the character code of the upper five characters having the largest frequency information in the vector character font storage unit.
The character pattern is read out from the memory 22, converted and generated by a vector / dot conversion unit 23, and stored in a font cache memory 24. However, font cache memory
The corresponding character code information is also stored so that the character pattern stored in 24 can be easily checked.

Thereafter, when information (character code and control code) is input from the host computer 1, it is checked whether a character pattern corresponding to the character code is already present in the font cache memory 24. If it is determined that the character pattern is present, the font cache is deleted. If the character pattern in the memory 24 is used as it is to develop it into a frame buffer, if not, the vector information is read from the vector font storage unit 22, and the vector / dot conversion unit 23 generates a font pattern for processing. In any case, one character pattern is transferred to the frame buffer 26.
When the counter bit information is developed, the corresponding counter bit information in the management table 25 is updated (incremented).

The contents of the management table memory 25 are saved in the nonvolatile memory 28 at a predetermined timing. At this timing, in the embodiment, the timing is every time one page is printed. However, the timing is not limited to this. When updating the frequency information corresponding to each character code, if the bit status is “11 _B (B indicates binary)”, no further update is performed, and other characters are not updated. The frequency information corresponding to the code group is decremented by one. In this case also, already, when the bit state is summer in the "00 _B", the processing of more Deikurimento is so as not to.

The process of updating the management table 25 is performed, for example, according to the flowchart shown in FIG. Note that the processing corresponding to this flowchart is performed in step S8 in FIG. 5 described later.

First, based on the character code received in step S20,
Calculate the position on the management table.

Then, in a step S21, it is determined whether or not the bit state of the frequency information for the received character code is “11B”. If it is 11B, no further update is possible, so the process proceeds to step S23, where "1" is subtracted from the frequency information of other character codes. At this time, the frequency information is already
No further decrement is performed for the character code of 00B. On the other hand, if it is determined that the frequency information corresponding to the received character code is not 11B, the process proceeds to step S22, and the value is incremented by "1".

A specific processing outline based on the above principle is shown below. At this time, all the counter bit information corresponding to the character code information in the nonvolatile memory 28 is “00 _B ”.
(For example, at the time of factory shipment).

Now, it is assumed that information is input from the host computer 1 in the order shown in FIG. "CR" in the figure is a carriage return code for prompting a print instruction, "L".
“F” indicates a line feed code (code for instructing line feed or one line of paper feed), and “FF” indicates a form feed code (page break code).

When such information is input, naturally, all character patterns corresponding to the input character code are
The vector information generated from the vector font storage unit 22 is converted by the vector / dot conversion unit, developed into the frame memory 26, and an image is formed by the printer unit 27.

At this time, the management table memory 25 (the non-volatile memory 28
The same applies to FIG. 3). As shown, for example,
The period "." Which is a character corresponding to the character code "2122 _H (H indicates a hexadecimal number)". ] Indicates that it has never been used, and the character code “4240 _H ”, that is, “thick” indicates that it has been used twice.

When the apparatus is used again, the character code corresponding to the frequently and frequently used character code and the character pattern corresponding to the character code are stored in the font cache memory 24 in a format as shown in FIG. Become. Accordingly, when the same sentence is input, the trouble of vectorizing / dotting frequently-used character patterns from vector information can be omitted, so that the throughput of the CPU 21a is remarkably improved. Further, if the capacity of the font cache memory 24 is slightly increased, the same effect can be obtained for other documents. For example, since particles and the like frequently occur in a normal document or the like, it can be easily understood that if these character patterns are held as pattern data in advance, the throughput of the CPU 21a is significantly improved.

<Explanation of Processing Procedure (FIGS. 5 and 6)> The processing described above is performed by the CPU 21a, and the processing procedure is organized and described as shown in FIG.

When the power of the apparatus is turned on, first, the management data stored and held in the nonvolatile memory 28 is transferred to the management table memory 25 in step S1. And the next step S2
Receives data from the host computer 1. When the data is received, the process proceeds to the next step S3, and it is determined whether or not the data is a character code. If it is determined that it is other than a character code, that is, if it is various control codes, the process proceeds to the next step S4, and a corresponding process is performed. For example, in the case of an LF (line feed) code, the development position of a character pattern to be described later with respect to the frame buffer 26 is updated.

On the other hand, if the received data is a character code, it is determined in the next step S5 whether the corresponding character pattern exists in the font cache memory 24 or not. At this time,
If the corresponding character pattern does not exist in the font cache memory 24, the vector information is read from the vector font storage unit 22 in the following step S6, and the character pattern is generated by the vector / dot conversion unit 23.
It unfolds to a position in the corresponding frame buffer 26. If there is a corresponding character pattern in the font cache memory 24, the flow advances to step S7 to read out the character pattern as it is and expand it on the frame buffer 26.

After the character pattern is developed in the frame buffer 26 in this way, the process proceeds to step S8, where the frequency information in the management table corresponding to the received character code is updated. Thereafter, it is determined whether or not the character pattern of the one-page sentence has been developed in the frame memory, and the above-described processing from step S2 is repeated until the series of character pattern development processing is completed.

When the development into the character pattern for one page is completed, the process proceeds to step S10, where the data in the frame buffer 26 is sequentially output to the printer unit 27 to form an image.
After that, in step S11, the updated contents in the management table memory 25 are transferred to the nonvolatile memory 28, and in step S2
Return to At this time, the process may be returned to step S1 and the process may be started in a new font cache memory 24 at all.

As described above, according to the present embodiment, characters having a high frequency of use are provided as character patterns, and thus throughput with respect to print processing can be significantly improved with a small memory capacity.

In addition, since the character frequency information is stored and retained even when the power is turned off, the font cache memory can be used the next time the apparatus is used, thereby improving operability. .

In the embodiment, a printing apparatus has been described as an example of an image forming apparatus.
The AM is not limited to this because it can be applied to a display device as it is. Further, the frequency information is not limited to two bits, and may be more than two bits.

[Effects of the Invention] As described above, according to the present invention, by controlling the cache memory that stores the dot data created from the non-dot data based on the counted frequency information, the cache memory can be dynamically and It becomes possible to use it efficiently.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a printing apparatus according to an embodiment, FIG. 2 is a view showing an example of received data relating to print output, FIG. 3 is a view showing the contents of a management table memory in the embodiment, FIG. FIG. 5 is a diagram showing an example of the contents of the font cache memory in the embodiment. FIG. 5 is a flowchart showing the printing process in the embodiment. FIG. 6 is a flowchart showing the contents of the management table updating process in FIG. . In the figure, 1 ... host computer, 2 ... printing device, 21
…… Control unit, 21a …… CPU, 21b …… ROM, 21c …… RAM, 22
... Vector font storage unit, 23 vector / dot conversion unit, 24 font cache memory, 25 management table memory, 26 frame buffer, 27 printer unit.

Claims (4)

(57) [Claims] 1. A character output control device for reading non-dot data corresponding to a character code input from the outside from a predetermined storage means, creating dot data and outputting the dot data at an output unit, wherein the input character code is A character which comprises: a counting means for counting the frequency of the data; a cache memory for storing the created dot data; and a control means for controlling the cache memory based on the frequency counted by the counting means. Output control device. 2. The character output control device according to claim 1, wherein said counting means updates frequency information indicating a frequency of said character code in units of one page. 3. A character output control method in a character output control device for reading non-dot data corresponding to a character code input from the outside from a predetermined storage means, creating dot data, and outputting the dot data at an output unit. A counting step of counting the frequency of the input character code; and a control step of controlling a cache memory for storing the created dot data based on the frequency counted in the counting step. Character output control method. 4. The character output control method according to claim 3, wherein in the counting step, frequency information indicating the frequency of the character code is updated for each page.