JPH08194461A - Character processing method and character processing device - Google Patents

Abstract

PURPOSE: To hold and use character patterns having a high using frequency without erasing them by judging whether or not the respective character patterns must be stored in a cache area on the basis of the bit map size after the character patternes are developed. CONSTITUTION: Processing is started by reading out data equivalent to a single character from a page buffer area 29b, and information of a registered character existing in the cache area 29a is searched, and whether or not read-out character data is stored in the cache area 29a is judged. When the character data is registered, a character pattern is read out of a pattern data area 32 in the cache area 29a, and is developed to a bit map area 29c, and the processing ends. When a read-out character is not registered in the cache area, font information of an outline is read out of a font memory 28, and whether or not the size falls within a cache object range is judged by information of the upper limit and the lower limit of the cache object size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a printing apparatus such as a laser beam printer capable of executing an electrophotographic process, and a character processing method for generating a character pattern based on outline font data read from an outline font memory, and a character processing method. It relates to a character processing device.

[0002]

2. Description of the Related Art Conventionally, an outline font is often used in a printing apparatus such as a laser beam printer capable of executing an electrophotographic process. The features of outline fonts are ease of character processing and sharpness, but the time required to generate a character pattern is longer than that using a dot pattern. Therefore, a character pattern that has been used once is registered in the cache memory in the state of being expanded into the same pattern, and when the same code is input again, the character pattern is read from the cache memory and used, thereby It suppresses the long time required for deployment.

Further, high-speed printing has been achieved by holding characters, which are often used in size, in a storage area in a printing device in a state of being developed in a dot pattern in advance.

[0004]

However, in the above-described conventional character processing method, when the cache memory area becomes full and the next character cannot be expanded, a special character pattern (large (Patterns such as characters and decorative characters) are removed from the cache memory, and if the cache memory area is insufficient, all the character patterns not used on the page are deleted and the characters are expanded.

Therefore, a large character such as a headline or special data different from the document data of an application which is normally used (special data different from the document data of an application using a different font) is printed. If this happens, this special data will be registered in the cache memory, and the frequently used character pattern data that has been learned and accumulated in the cache memory will be erased, and the printing speed will decrease accordingly. There was a problem.

Furthermore, in order to achieve high-speed printing, characters of a commonly used size which are stored in the printing device in advance in the state of being developed into a dot pattern are increased in the type of font and the purpose of use of the printing device. Diversification has made it difficult to limit it. In order to cope with the increase in font types and diversification of purposes of use, it is necessary to increase the memory capacity, and there is a problem that the cost of the device is significantly increased.

In view of the above-mentioned conventional problems, the present invention enables a character pattern to be stored and used without erasing a frequently used character pattern when registering a character pattern in a storage medium such as a cache memory. An object of the present invention is to provide a character processing method and a character processing device that can improve speed and reduce cost.

[0008]

In order to achieve the above object, the character processing method of the first invention stores each character pattern generated based on the outline font pattern of each character read from the outline font memory. A first storage area and a second storage area for storing a criterion based on a character size of whether or not to store a character pattern in the first storage area are secured, and the second storage area is stored in the second storage area. It is also configured to determine whether or not to store each character pattern in the first storage area based on the stored determination criteria.

Further, in the above-mentioned first invention, it is desirable that the criterion based on the character size is a bitmap size after the character pattern is developed.

In order to achieve the above object, the character processing device of the second invention is based on an outline font memory for storing outline font data of each character and outline font data of each character read from the outline font memory. First storage means for storing each generated character pattern, second storage means for storing determination information for determining whether or not to store the character pattern in the first storage means, and the second storage means. The determination means refers to the determination information stored in the storage means and determines whether or not to store each character pattern in the first storage area.

Further, in the second aspect of the invention, it is preferable that the determination information is a bitmap size after the character pattern is developed.

[0012]

With the above arrangement, according to the character processing method of the first aspect of the present invention, the first storage area is based on the judgment standard (for example, the bit map size after the character pattern expansion) stored in the second storage area. Since it is determined whether or not to store each character pattern in the cache area (for example, in the cache area), character patterns with a high probability of erasing character patterns with a high hit rate and character patterns with a low hit rate can be determined. Therefore, such a character pattern is not stored in the first storage area, and only the character pattern that meets the condition is stored. This makes it possible to hold and use a frequently used character pattern in the first storage area without erasing it, even though it is a simple character processing method.

According to the character processing device of the second invention, the judgment means refers to the judgment information stored in the second storage means, and whether or not each character pattern is stored in the first storage means. Therefore, it is possible to determine a character pattern having a high probability of erasing a character pattern having a high hit rate and a character pattern having a low hit rate. The pattern is not stored, but only the character pattern that meets the conditions is stored. This allows
It becomes possible to hold and use a frequently used character pattern in the first storage means without erasing it.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the internal structure of a character processing apparatus for carrying out a character processing method according to an embodiment of the present invention.

The character processing device is composed of a laser beam printer (hereinafter referred to as LBP) capable of registering a character pattern and a fixed form (form data) from an external data source. That is, this LBP inputs and stores character information (character code), form information, macro commands, or the like supplied from an external device (21 in FIG. 2) such as a host computer connected to the outside and stores them. It has a function of forming a corresponding character pattern, form pattern, or the like according to the information of 1, and forming an image on a recording paper as a recording medium.

In the figure, 10 is an LBP main body, 11 is an operation panel on which switches for operation and an LED display are arranged, and 12 is overall control of the LBP and character information supplied from an external device. Is a printer control unit (controller) for analyzing the. This control unit 12
Mainly converts character information into a video signal having a corresponding character pattern and outputs the video signal to the laser driver 13.

The laser driver 13 is a semiconductor laser 14.
Is a circuit for driving the laser beam, and turns on / off the laser beam 15 emitted from the semiconductor laser 14 according to the input video signal. The laser light 15 is the rotating polygon mirror 1.
It is shaken in the left-right direction at 6 and scans on the electrostatic drum 17. As a result, an electrostatic latent image having a character pattern is formed on the electrostatic drum 17. The latent image is developed by the developing unit 18 around the electrostatic drum 17 and then transferred to the recording paper.

A cut sheet is used for this recording paper,
The cut sheet recording paper is stored in the paper cassette 19 mounted on the LBP 10, and the paper feed roller 20 and the transport roller 2
1, 22 is taken into the apparatus and the electrostatic drum 17
Supplied to

FIG. 2 is a block diagram showing the internal structure of the controller 12 shown in FIG.

The controller 12 inputs print information mainly from an external device 21 such as a host computer,
Image data such as a corresponding character pattern is created according to the print information. Further, the created image data is output to the printer engine 22, and the printer engine 2
2 is made to form an image on a recording medium such as paper or an OHP sheet.

In FIG. 2, 23 is an input interface for receiving print data from the external device 21, 25 is a system bus for internal communication of the controller 12, and 26 is for controlling the entire apparatus. Reference numeral 27 is a CPU, and 27 is a ROM for storing the operating procedure of the CPU 26.
28 is a font memory for storing outline font data. Reference numeral 29 is a RAM used to store a work area of the CPU 26, a cache area described later, and the like, and 30 is an output interface for transmitting image data to be formed to the printer engine 22.

Here, the RAM 29 is, as shown in the figure, a cache area 29a for storing the pattern data expanded into a dot pattern and its management information, and a page buffer area 2 for storing the received data from the external device 21.
9b and a bitmap area 29c for storing image data to be output to the printer engine 22.

FIG. 3 is a diagram showing the structure of the cache area 29a shown in FIG. 2. Reference numeral 31 denotes a cache management table, which includes cache target information 33, which will be described later, and registered character information. Reference numeral 32 is a pattern data area for storing the pattern data expanded into a dot pattern, and 33 is the cache target information stored in the cache management table 31.

The cache target information 33 has information on the upper and lower limits of the cache target size of a character pattern in addition to the size information of the cache memory itself, and is used for determining whether or not the character pattern can be stored in the cache area 29a. Will be referred to in the procedure described later. Further, here, the cache target size is defined as the cache memory usage after the character pattern expansion.

Next, the character data processing operation (character processing method) in the character processing apparatus having the above configuration will be described with reference to the flowchart shown in FIG. FIG. 4 is a flowchart showing an example of a character data processing procedure in the character processing device of this embodiment. For the sake of explanation, it is assumed that characters are registered in the cache area 29a prior to receiving print data. Further, it is assumed that a value is set also in the cache target information 33 by a procedure (not shown) from the operation panel 11 or the like. The print data is received from the external device 21 in parallel with the process of this embodiment, and the received print data is stored in the page buffer area 29b via the input interface 23 and the system bus 25. .

First, the processing is started by reading the data for one character from the page buffer area 29b (step S41). Then, the information of the registered character in the cache area 29a is searched to determine whether the read character data is already stored in the cache area 29a (step S42).

If it is determined in step S42 that the read character data is registered, the process proceeds to step S43, the corresponding character pattern is read from the pattern data area 32 in the cache area 29a, and the bit map area is read. 29c (step S44), 1
Terminates character processing.

On the other hand, if it is determined in step S42 that the read character is not yet registered in the cache area, the process proceeds to step S45 to read the font information of the corresponding outline data from the font memory 28. Then, when a character pattern is generated based on the read data, whether the size of the character pattern falls within the cache target range is determined by the upper and lower limit information of the cache target size in the cache target information 33. Is determined (step S46).

If it is to be cached, a normal caching process is executed (step S47), then the corresponding character pattern is read (step S43) and expanded in the bitmap area 29c (step S44) to process one character. To finish.

If it is determined in step S46 that the size of the character pattern is not within the cache target range, the character area is expanded using the work area of the CPU 26 (step S48), and then the bitmap area is created. 29c (step S44), and the processing for one character is completed.

The present invention is not limited to the illustrated embodiment, and various modifications can be made. For example, there are the following modifications.

(1) Although the immediate value is used in the cache target information 33 in the above-described embodiment, this may be configured as shown in FIG. 5 and may be a value relatively obtained by the ratio to the cache size. In this case, it is also possible to dynamically change the upper and lower limit sizes according to the cache size by automatically performing recalculation when the cache size changes.

(2) In the modified example (1), the method of designating the upper limit and the lower limit may be combined with the direct value designating method of the above embodiment. In this case, only the upper limit value, which has a large effect on the cache capacity, can be dynamically changed in proportion.

(3) In the above-described embodiment and the modified examples (1) and (2), the setting of the value to the cache target information 33 is performed not by the operation panel 11 but by the external device 21.
It may be based on a control command to the printing device from an external device such as. In this case, the operation from the user's panel can be eliminated, and the cache registration condition can be dynamically changed in the print data, which enables more detailed cache control.

(4) In the above-described embodiment and the above-described modified examples (1) and (2), the value of the cache target information 33 is set only by the system default value, and only the specification of whether cache restriction can be executed or not is executed. It may be possible to execute. In this case, since the system recommended value is used, the user does not have to be aware of the set cache size.

(5) In the above-described embodiment, the cache size specifying method may be an indirect specifying method such as font size specification by the number of points. In this case, an internal recalculation is necessary, but the specification method is easy for the user to understand.

(6) In the above embodiment, the setting value for the cache target information 33 may be the value set in the nonvolatile memory such as NVRAM.

(7) In the above-mentioned embodiments, the laser beam printer device has been described as an example, but the present invention is not limited to this, and a printer of another printing system such as an ink jet printer or a thermal transfer printer is used. It is also applicable to the device.

(8) The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. The present invention can also be applied to the case where it is achieved by supplying a program for implementing the present invention to a system or an apparatus.

[0041]

As described above in detail, according to the character processing method of the first invention, each character pattern generated based on the outline font pattern of each character read from the outline font memory is stored. 1
And a second storage area for storing a criterion based on the character size of whether or not to store a character pattern in the first storage area, and stored in the second storage area. It is determined whether or not each character pattern is stored in the first storage area based on the determination criteria.
Only the character patterns that meet the conditions are stored in the storage area of. As a result, it is possible to retain and use a frequently used character pattern in the first storage area without erasing, even though it is a simple character processing method. The area can be used efficiently, the cost of the execution apparatus can be reduced, and the printing speed can be improved when the present invention is applied to, for example, a printing apparatus.

According to the character processing apparatus of the second invention, an outline font memory for storing outline font data of each character and each character generated based on the outline font data of each character read from the outline font memory. A first storage unit that stores a pattern; a second storage unit that stores determination information for determining whether to store a character pattern in the first storage unit; and a second storage unit that stores the determination information. Since the determination means for determining whether or not to store each character pattern in the first storage area is provided with reference to the determination information stored in the first storage area, the first storage means stores characters that meet the conditions. Only patterns are stored. As a result, the frequently used character pattern can be retained and used in the first storage unit without being erased, and the storage area of the first storage unit can be efficiently used without increasing the storage capacity. This makes it possible to reduce the cost of the printing apparatus and improve the printing speed when the present invention is applied to, for example, a printing apparatus.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an internal configuration of a character processing device for carrying out a character processing method according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a controller 12 in FIG.

FIG. 3 is a diagram showing a configuration of a cache area 29a in FIG.

FIG. 4 is a flowchart showing an example of a character data processing procedure in the embodiment.

FIG. 5 is a diagram showing cache target information in a modified example.

[Explanation of symbols]

 10 LBP 12 controller 21 external device 26 CPU 27 ROM 28 font memory 29 RAM 29a cache area 29b page buffer area 29c bitmap area 31 cache management table 33 cache target information

Claims (4)

[Claims] 1. A first storage area for storing each character pattern generated based on an outline font pattern of each character read from an outline font memory, and whether or not to store the character pattern in the first storage area. A second storage area for storing a criterion based on the character size, and based on the criterion stored in the second memory area,
A character processing method, comprising: determining whether or not to store each character pattern in the first storage area. 2. The criterion based on the character size is
2. The character processing method according to claim 1, wherein the bitmap size after the character pattern is expanded is used. 3. An outline font memory for storing outline font data of each character, and a first storage means for storing each character pattern generated based on the outline font data of each character read from the outline font memory. With reference to the second storage unit that stores determination information for determining whether to store a character pattern in the first storage unit and the determination information stored in the second storage unit, A character processing device comprising: a determination unit that determines whether or not to store each character pattern in the first storage area. 4. The character processing device according to claim 3, wherein the determination information is a bit map size after character pattern expansion.