JPH0740597A - Printer - Google Patents

Abstract

PURPOSE:To provide the high speed printing output by utilizing effectively the capacity of memory while keeping constant the quality level of characters of printing output. CONSTITUTION:A printer comprises a plotting section 2 for plotting a printing data from a higher-order device 1 on an image buffer 7, a character forming section 3 for feeding bit map fonts A to the plotting section and a printing section 8 for print outputting dot data plotted on the image buffer 7. Also an outline font storing section 5 for storing outline fonts 5a into the character forming section 3, a font cache ROM 6 in which bit map fonts A provided by the regular development output and a font control section 4 provided with font cache informations 4a such as character codes, character sizes and the like of the bit map fonts A stored preliminarily in the cache ROM 6 are provided combinedly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer device for printing out print data from a host device, and more particularly to a printer device for shortening the printing time and improving the quality of printout of characters.

[0002]

2. Description of the Related Art A conventional printer device uses a bit map font from a character generation unit for print output of characters in received print data. The font data that can be used by the character generator includes a bitmap font and an outline font. For example, for small characters of 10 points or 12 points that are frequently used for printout, a prepared bitmap font is used. For other point sizes, the outline font was used to expand to a bitmap font of the required size and then printed out. In this way, by expanding the outline font into a bitmap, the size of characters to be printed is variable.

[0003]

However, in the above-mentioned conventional example, since the process of expanding the outline font into the bitmap font has a great influence on the printing time, all the characters of the print data are converted from the outline font to the bitmap font. Naturally, there was a problem that the printing time would be delayed when expanded.

Further, the font of the outline font that is expanded into a bitmap and the character of the print output that is stored in advance in the bitmap font are changed, and the overall balance of the characters that are printed out is deteriorated, making it difficult to read. In some cases, there was the inconvenience.

However, a large amount of storage capacity is required to align all the character sizes of a certain font with a bitmap font, and when all characters are printed out with an outline font, the printing time is too long. There was an inconvenience that it would be hung up.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printer apparatus which improves the disadvantages of the prior art, and in particular makes it possible to obtain a high-speed print output by effectively utilizing the capacity of the memory while keeping the quality of characters of the print output constant. The purpose is to do.

[0007]

According to the present invention, a drawing unit for developing print data from a higher-level device into dot data and drawing it in an image buffer, and a bitmap font corresponding to a character in the print data as a drawing unit. In a printer device including a character generation unit to be supplied and a printing unit to print out dot data drawn in an image buffer, an outline font storage unit to store an outline font in the character generation unit and a normal expansion of outline fonts. A font cache ROM that stores in advance bitmap fonts obtained by output, and this cache ROM
A font management unit that has font cache information such as the character code and character size of the bitmap font stored in is also provided, and the character generation unit extracts the outline font from the outline font storage unit and expands it into a bitmap. A first supplying means for supplying a font to the drawing unit, and the cache RO in advance.
A second supply means for extracting the bitmap font stored in M and supplying it to the drawing unit; and a selection means for selecting the first supply means or the second supply means based on the font cache information. Etc. are adopted. This aims to achieve the above-mentioned object.

[0008]

When the print data is received from the host device 1, the drawing unit 2 sends the character code and the point size to the character generating unit 3 and requests the bitmap font A. The selection unit 3c of the character generation unit 3 searches the font cache information 4a of the font management unit 4 from the character code and the point size to determine whether the bitmap font A of the character is stored in the cache ROM 6.

The selection means 3c controls the font cache information 4
When the point size of the character code is found in a, it means that the bitmap font A has already been created in the cache ROM 6, so the second supply means 3b of the character generation unit 3 is activated to activate the font cache. The bitmap font A on the cache ROM 6 is accessed according to the information 4a and the data is transferred to the drawing unit 2. If it is not included in the font cache information 4a, the first supplying means is activated and the outline font 5a as in the conventional case.
Is used to develop a bitmap to create a bitmap font A, and then data is transferred to the drawing unit 2.

The drawing unit 2 reads the number of characters per line or the number of lines per page from the print data, and writes the bitmap font A as dot data in the image buffer 7 according to these formats. When the printing unit 8 is, for example, a serial printer method, the printing unit 8 prints out the dot data accumulated in the image buffer 7 line by line.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention, in which a printer device 10 develops print data from a higher-level device 1 into dot data and draws it in an image buffer 7, A character generator 3 that supplies a bitmap font A corresponding to characters in print data to a drawing unit
And a printing unit 8 that prints out the dot data drawn in the image buffer 7.

The character generation unit 3 includes an outline font storage unit 5 for storing an outline font 5a, a font cache ROM 6 in which a bitmap font A obtained by a normal expansion output of the outline font 5a is stored in advance, and this cache. A font management unit 4 having font cache information 4a such as a character code and a character size of the bitmap font A stored in the ROM 6 is also provided.

Further, the character generator 3 fetches the outline font 5a from the outline font storage 5 and develops the bitmap into the bitmap font A by supplying the bitmap font A to the drawing unit 2 and a cache in advance. The second supply means 3b for extracting the bitmap font A stored in the ROM 6 and supplying it to the drawing unit 2, and the first supply means 3a or the second supply means 3
The selection means 3c selects b based on the font cache information 4a.

More specifically, the host device 1
The device is a device such as a workstation or a personal computer that creates sentences and graphics, and print data is transmitted from one or a plurality of host devices 1 to the printer device 10 through a cable or the like. Usually, the print data includes a character code and a code that describes the character size and typeface. The character generating unit 3 supplies the corresponding bitmap font A from these character codes to the drawing unit 2. The drawing unit 2 reads the number of characters per line or the number of lines per page from the print data, and writes the bitmap font A as dot data in the image buffer 7 in accordance with these formats. Here, since the printing unit 8 employs the serial printer method, the dot data accumulated in the image buffer 7 is printed out line by line.

An outline font storage unit 5 provided along with the character generation unit 3 stores an outline font 5a in which the outline of a character is represented by a vector or the like. The outline font has excellent workability, and various point sizes can be expressed from one outline font, and italic characters can be generated. The outline font 5a is called by the font management unit 4, then expanded by the character generation unit 3 into the bitmap font A at the point size described in the print data, and then supplied to the drawing unit 2. Although the ROM is adopted as the outline font storage unit 5 here, if a large number of typefaces can be printed, this may be used as a hard disk.

Since the bitmap expansion of the outline font 5a takes a long time to process, a bitmap font A expanded in advance by the character generator 3 is stored in the cache ROM 6 for a character that is frequently used, and the outline font expansion process is performed. By supplying the bitmap font to the drawing unit 2 without going through, the printing process is speeded up. Since the bitmap font A stored in the cache ROM 6 is created by the bitmap expansion of the outline font 5a by the character generation unit 3, the quality of the characters printed out is not limited to that of the characters even if the cache ROM 6 is used. The same high quality as when the outline font 5a is expanded can be maintained.

Further, the font management unit 4 is a cache RO.
The font cache information 4a such as the character code and the character size of the bitmap font A stored in M6 is provided. For example, when it is configured to print multiple fonts, the font cache information is the type of font (typeface), the character code, the point size that is the character size, and the bitmap font specified by these information. Address information in the cache ROM 6 of A. Note that when a plurality of character styles are expressed from one typeface, for example, when italic characters and shaded characters are generated from the outline font 5a, these character style information is also a component of the font cache information 4a. Become.

The selecting means 3c of the character generating section 3 takes out the bitmap font A of the cache ROM by utilizing the font cache information 4a, or takes out the outline font 5a from the outline font storage section 5 and expands the bitmap. Determines whether to supply the bitmap font A to the drawing unit 2.

According to the above-described first embodiment, the frequently used characters are cached as a bitmap font in the cache R.
This character is stored in advance in the OM, and since this character is supplied from the character generation unit to the drawing unit without a bitmap expansion of the outline font, the time required for the outline font expansion can be shortened. Since the bitmap font stored in the cache ROM is a bitmap font obtained by the normal expansion processing of the character generation unit, a cache that speeds up this print output especially in a printer with a relatively low resolution such as a serial dot printer. Even if the ROM is used, there is an effect that it is possible to print out with a quality that is no different from the character by the bitmap expansion of the outline font.

Next, a second embodiment according to the present invention will be described with reference to the drawings.

In the second embodiment, the font management unit 4 is
As shown in FIG. 2, coordinate detecting means 4b for detecting the coordinate information of the outline font A at the bitmapped coordinates 9 used for bitmap expansion of the outline font A, and font coordinate information 9a detected by the coordinate detecting means 4b. The clipping range determining means 4 for determining the bitmap clipping coordinates 9b, which is the minimum coordinate range when the outline font A is bitmap-developed by using.
and c.

Further, the character generating section 3 is adapted to obtain the cut-out bitmap data B by expanding the outline font 4a into a bitmap within the range of the bitmap cut-out coordinates 9b determined by the cut-out range determining means 4c. There is.

Further, the font management unit 4 reproduces the bitmap font A by using the cutout bitmap data B and the bitmap cutout coordinates 9b.
have d.

The cut-out bitmap data B normally generated by the character generator 3 is stored in the cache ROM 6 in advance, and the cut-out coordinate 9b corresponding to the cut-out bitmap data B is registered in the font cache information 4a. .

The other structure is the same as that of the first embodiment.

The second embodiment will be described in detail. In the case of Japanese fonts, if the point size to be printed out is determined, the capacity of one-bit bitmap font data is constant, but in the case of European fonts, the width C of the character required per character depending on the character even if the point size is determined. And the height D are different. As shown in FIG. 3 (A), the width C1 of the character "m", the width C2 of the character "e", and the width C of the character "l".
3 is different from each other, and as shown in FIG.
Character height D1 and "l" character height D3 and "y"
The height D5 of the character is different. As with Japanese fonts, if the character size is fixed at the point size, the control becomes easier, but if the capacity per character is large, it takes longer to print out the bitmap expansion processing and the cache ROM 6 etc. Will require a large amount of memory.

Therefore, in the second embodiment, when the bitmap is expanded in the minimum range and the characters are stored in the cache ROM 6 in advance, the characters are stored in the minimum capacity, so that the character quality of the printed output is improved. It is an object of the present invention to provide a printer device that can obtain a high-speed print output by effectively utilizing the memory capacity while keeping it constant.

The operation is as shown in FIG. 4 and FIG.
First, the outline font 5a of the character is overlaid on the bit-mapped coordinates 9 corresponding to the resolution of the printing unit 8 according to the point size of the character, and the coordinate detecting means 4b detects each coordinate when the character is represented by a straight line. The cutout range determining means 4c calculates the bitmap cutout coordinates 9b which is the minimum range on the bitmapped coordinates of the outline font based on the font coordinate information 9a. Figure 4 (A)
The case of "m" is shown in FIG. 4 and the case of "l" is shown in FIG.
The case of "y" is shown in (C).

Next, the character generator 3 develops a normal outline font bitmap according to the bitmap cutout coordinates 9b. In the font cache information 4a relating to the cut-out bitmap data B obtained by this bit map expansion, a bit map cut-out coordinate 9b is written in addition to the character code and the like. When the cache ROM 6 is reproduced, the reproduction means 4d reproduces the extracted bitmap data B and a bitmap font based on the bitmap extraction coordinates included in the font cache information 4a.

There are various methods for the bitmapped coordinates 9, but the maximum value of the coordinates is determined by the resolution and point size of the printing unit 8. For example, the resolution is 400 [dp
i] (dots / inch), when a 12-point character is bitmap-developed, assuming that 12 points are reduced to 1 inch, a bitmapped coordinate 9 of 400 dots × 400 dots is obtained.

The coordinate detecting means 4b converts the vector data of the outline font 5a into the bitmapped coordinates 9
Are replaced with the coordinates. As shown by enlarging the upper left part of "m" in FIG. 5, the coordinate detecting means 4b is a point p which makes a straight line of the outline font 5a on the given bit-mapped coordinates 9 and a point which can approximate the curved line part to a straight line. p and are detected. The font coordinate information 9 composed of the coordinates of these points and the connection between the points by the coordinate detecting means 4b.
a is detected.

Usually, various processings are performed to improve the quality of print-output characters by using the font coordinate information 9a. For example, smoothing the edges of characters, processing to prevent the lines that make up characters from overlapping when the point size is small, and outline fonts that have line information of the same thickness attached to the lines that make up characters. Therefore, for example, a process of making the thicknesses of three lines forming the character "three" have the same number of dots is performed at the level of the font coordinate information 9a.

The cut-out range fixing means 4c calculates the maximum coordinates and the minimum coordinates from the font coordinate information 9a detected by the coordinate detecting means 4b and fixes the bitmap cut-out coordinates 9b which is the minimum range for bit map. .
The character generation unit 3 performs a development process based on the bitmap cutout coordinates 9b to obtain the cutout bitmap data B. This cut-out bitmap data B cannot be supplied to the drawing unit 2 as it is, and the reproduction means 4d of the font management unit 4 is used.
Although it is necessary to reproduce A into the bitmap font by using, the processing speed is increased because the bitmap is expanded in the minimum range, and a large capacity reduction is achieved when the cut-out bitmap data B is stored in the cache ROM 6. There is. The reproducing means 4d reproduces based on the lower left which is the minimum value of the bitmap cutout coordinates.

According to the second embodiment described above, in the case of a proportional font such as a European font having different widths and heights depending on characters, the cut-out range determining means 4c determines the minimum necessary range for bitmap expansion and bitmap expansion. Therefore, the expansion processing is fast, and by storing the cut-out bitmap data in the cache ROM in advance, the capacity of the cache ROM 6 can be reduced and the printing processing can be speeded up. It has the effect of maintaining dignity.

A third embodiment will be described with reference to the drawings.

In the third embodiment, the cache ROM 6
In advance, font coordinate information 9a generated by the coordinate detecting means 4b of the font management unit 4 and generated in the course of the normal expansion processing is stored in advance.

Other configurations are similar to those of the first and second embodiments.

The third embodiment will be described in detail. The target data format of the cache ROM 6 is only bitmap data in the first and second embodiments. Even if you have bitmap data for a character with a small point size, the memory capacity will be small, but for a character with a large point size, even if you try to increase the cache hit ratio as much as a small character, the memory capacity is limited. Therefore, there is a problem that the cache effect cannot be obtained for a large character over a certain amount for the capacity.

Therefore, in the third embodiment, the cache ROM is allowed to function effectively regardless of the size of the point size, so that the quality of the characters of the printed output can be kept constant and the capacity of the memory can be effectively utilized to achieve high speed. It is an object of the present invention to provide a printer device that obtains a stable print output.

As shown in the second embodiment, the coordinate detecting means 4b of the font managing section 4 detects the font coordinate information 9a according to the resolution and point size of the printing section 8. Unlike bitmap fonts whose capacity increases in proportion to the increase in point size, the amount of information is constant regardless of changes in point size.

This font coordinate information 9a is cached in R
By storing it in the OM 6 in advance, the steps of extracting the outline font 5a from the outline font storage unit 5 and detecting the font coordinate information 9a in the bitmap coordinates 9a can be omitted, and the print output can be sped up.

The font cache information 4a is also registered with the fact that the data stored in the cache ROM 6 is font coordinate information, and accordingly, the character generator 6 develops a bitmap from the font coordinate information 9a. Start processing.

As described above, in the third embodiment, since the cache ROM has coordinate data instead of bitmap data, even if a character having a large point size is used, the cache ROM 6 is made to function effectively, and in the conventional RAM cache or the like. The hit ratio that cannot be obtained can be maintained, and the font coordinate information generated during the normal bitmap expansion process of the outline font of the character generation part is used for the cache ROM data, so the print output is kept high quality. It has the effect of being able to do things.

[0045]

As described above, according to the present invention, a frequently used character is stored in advance in the cache ROM, and the character is converted from the character generation unit to the drawing unit without bit map expansion of the outline font. Since the bitmap font is supplied to, the time required for developing the outline font can be shortened and the cache ROM can be used.
Since the bitmap font stored in is a bitmap font obtained by the normal expansion processing of the character generation unit, even if a cache ROM that speeds up this print output is used, it is possible to identify the character by the bitmap expansion of the outline font. It is possible to provide an unprecedented excellent printer device that can print out with the same quality.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram showing a configuration of a second embodiment of the present invention and showing bitmapped coordinates.

FIG. 3 is an explanatory diagram showing the characteristics of a European font, where (A) shows the width of a character and (B) shows the height of the character.

FIG. 4 shows an example in bitmap coordinates, (A)
It is explanatory drawing showing the case where "m" is set to (b), "l" is set to (B), and "y" is set to (C).

FIG. 5 is an enlarged view of the upper left portion of “m” for explaining the operation of the coordinate detecting means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper device 2 Drawing part 3 Character generation part 3a First supply means 3b Second supply means 3c Selection means 4 Font management part 4a Font cache information 4b Coordinate detection means 4c Cutout range determination means 4d Reproduction means 5 Outline font storage part 5a Outline font 6 Cache ROM 7 Image buffer 8 Printing section 9 Bitmapped coordinates 9a Font coordinate information 9b Bitmap cutout coordinate 10 Printer device A Bitmap font B Cutout bitmap data C Character width D Character height

Claims (5)

[Claims] 1. A drawing unit that expands print data from a higher-level device into dot data and draws it in an image buffer, and a character generation unit that supplies a bitmap font corresponding to characters in the print data to the drawing unit. In a printer device including a printing unit that prints out dot data drawn in the image buffer, an outline font storage unit that stores an outline font in the character generation unit and a normal expansion output of the outline font can be obtained. A font cache ROM storing a bitmap font in advance and a font management unit having font cache information such as a character code and a character size of the bitmap font stored in the cache ROM are provided side by side, and the character generating unit is Outliner from the outline font storage section And a second supplying means for supplying the bitmap font to the drawing unit by extracting the bitmap font and expanding the bitmap, and a second supplying means for extracting the bitmap font stored in advance in the cache ROM and supplying the bitmap font to the drawing unit. A printer apparatus comprising: a supply unit; and a selection unit that selects the first supply unit or the second supply unit based on the font cache information. 2. The font management unit uses coordinate detection means for detecting coordinate information of the outline font in bitmap coordinates used for bitmap expansion of the outline font, and font coordinate information detected by the coordinate detection means. And a clipping range determining means for determining bitmap clipping coordinates, which is the minimum coordinate range when the outline font is bitmap-expanded, and the character generator is a bitmap determined by the clipping range determining means. 2. The printer device according to claim 1, wherein the clipped bitmap data is obtained by expanding the outline font into a bitmap within the clipping coordinate range. 3. The printer device according to claim 2, wherein the font management unit has a reproducing means for reproducing a bitmap font using the clipped bitmap data and the bitmap clipped coordinates. 4. The cache ROM stores in advance the cut-out bitmap data normally generated by the character generation unit, and the font cache information includes the cut-out coordinates corresponding to the cut-out bitmap data. The printer device according to claim 2 or 3, wherein: 5. The cache ROM stores in advance font coordinate information generated in the course of a normal expansion process detected by the coordinate detecting means of the font management unit. 4. The printer device according to item 4.