JP2580965B2 - Printer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A conventional printer apparatus uses a bitmap font from a character generator for printing out 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, a small character of about 10 points or 12 points frequently used for print output uses a bitmap font prepared in advance, Other point sizes were printed out after being expanded into bitmap fonts of the required size using outline fonts. In this way, the size of characters to be printed is made variable by developing the outline font into a bitmap.

[0003]

However, in the above-mentioned prior art, since the processing of expanding the outline font into a bitmap font greatly affects the printing time, all the characters of the print data are converted from the outline font to the bitmap font. There is a problem that the printing time naturally becomes slow when the image is developed.

[0004] In addition, the font of the outline font bitmap expansion and the character of the print output by the bitmap font stored in advance are changed, and the overall balance of the printed output character is deteriorated, making it difficult to read. In some cases, there was an inconvenience.

However, a large amount of storage capacity is required to make all the character sizes of a certain font equal to the bitmap font, and printing time is required when all characters are to be printed out in the outline font. There was an inconvenience of hanging.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printer device which solves the disadvantages of the prior art, and in particular provides a high-speed print output by effectively utilizing the capacity of a memory while keeping the quality of print output characters constant. To do so.

[0007]

According to the present invention, a drawing unit for developing print data from a host device into dot data and drawing the image data in an image buffer, and a bitmap font corresponding to characters in the print data are stored in the drawing unit. In a printer device including a character generator to be supplied and a printing unit to print out dot data drawn in an image buffer, an outline font storage unit that stores an outline font in the character generator, and a normal development of the outline font A font cache ROM in which bitmap fonts obtained by output are stored in advance, and a cache ROM
A font management unit having font cache information such as a character code and a character size of a bitmap font stored in a font management unit is provided.The character generation unit extracts an outline font from an outline font storage unit and performs bitmap development by extracting the outline font. First supply means for supplying a font to a drawing unit;
A second supply means for supplying removed bitmap fonts stored in M in the drawing unit, have a selecting means for selecting on the basis of the first feed means or the second font cache information supply means for , The font management unit
Used for bitmap expansion of outline font
The outline font in bitmapped coordinates
Coordinate detecting means for detecting the coordinate information of the
Outline font using the font coordinate information detected by the column.
Minimum coordinate range when bitmap expansion of fonts
The extraction range that determines the bitmap extraction coordinates
Surrounding determination means, wherein the character generation unit
Bitmap extraction determined by the range determination means
Bitmap outline fonts within coordinate range
Extract bitmap data by expanding
, Etc. 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 selecting means 3c of the character generator 3 searches the font cache information 4a of the font manager 4 from the character code and the point size, and determines whether or not the bitmap font A of the character is stored in the cache ROM 6.

[0009] The selecting means 3c sets the font cache information 4
a, the bitmap font A is already created in the cache ROM 6 when the point size of the character code is found. The bitmap font A on the cache ROM 6 is accessed according to the information 4a, and data is transferred to the drawing unit 2. If the font information is not included in the font cache information 4a, the first supply unit is activated to start the outline font 5a as in the related art.
Is used to develop a bitmap, and a bitmap font A is created, and then data is transferred to the drawing unit 2.

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

[0011]

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 host device 1 into dot data and renders it in an image buffer 7; A character generator 3 for supplying a bitmap font A corresponding to characters in print data to a drawing unit
And a printing unit 8 for printing out dot data drawn in the image buffer 7.

The character generating section 3 includes an outline font storage section 5 for storing an outline font 5a, a font cache ROM 6 for previously storing a bitmap font A obtained by normal development output of the outline font 5a, 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.

The character generating section 3 takes out the outline font 5a from the outline font storage section 5 and develops it into a bitmap to supply a bitmap font A to the drawing section 2; A second supply unit 3b for taking out the bitmap font A stored in the ROM 6 and supplying it to the drawing unit 2;
a selecting means 3c for selecting b based on the font cache information 4a.

To describe this in more detail, the host device 1
This is a device such as a workstation or a personal computer that creates text or graphics, and print data is transmitted from one or more host devices 1 to the printer device 10 via a cable or the like. Normally, print data includes a character code and a code that describes a character size and a typeface. The character generator 3 supplies a corresponding bitmap font A to the drawing unit 2 from these character codes. The drawing unit 2 reads the number of characters per line and the number of lines per page from the print data, and writes the bitmap font A as dot data into the image buffer 7 in accordance with these formats. Here, since the printing unit 8 employs the serial printer method, the dot data stored in the image buffer 7 is printed out line by line.

An outline font storage 5 provided with the character generator 3 stores an outline font 5a expressing the outline of a character by a vector or the like. Outline fonts are excellent in workability, and can represent various point sizes from one outline font and generate italic characters. The outline font 5 a is called by the font management unit 4, developed by the character generation unit 3 into a bitmap font A at the point size described in the print data, and supplied to the drawing unit 2. Although the outline font storage unit 5 employs a ROM in this embodiment, a hard disk may be used when a large number of fonts can be printed.

Since the bitmap expansion of the outline font 5a takes time to process, the bitmap font A expanded by the character generator 3 is stored in the cache ROM 6 in advance for frequently used characters, and the outline font expansion processing is performed. By supplying the bitmap font to the drawing unit 2 without going through the process, 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 to be printed out can be reduced even if the cache ROM 6 is used. Can maintain the same high quality as when the outline font 5a is developed.

Further, the font management unit 4 has a cache RO
Font cache information 4a such as the character code and character size of the bitmap font A stored in M6 is provided. For example, when a plurality of typefaces are configured to be printable, the font cache information includes the type of typeface (type face), character code, point size which is a character size, and a bitmap font specified by the information. A and the address information in the cache ROM 6 of A. 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, the character style information is also a component of the font cache information 4a. Become.

The selecting means 3c of the character generating unit 3 extracts the bitmap font A from the cache ROM using the font cache information 4a, or extracts the outline font 5a from the outline font storage unit 5 and develops the bitmap. It is determined whether or not to supply the bitmap font A to the drawing unit 2.

According to the first embodiment described above, frequently used characters are stored in the cache R as bitmap fonts.
This character is stored in advance in the OM, and for this character, the bitmap font is supplied from the character generation unit to the drawing unit without undergoing the outline font bitmap development, so that the time required for the outline font development can be reduced. Since the bitmap font stored in the cache ROM is a bitmap font obtained by the normal expansion processing of the character generating unit, a cache for speeding up this printing output is particularly used in a printer having a relatively low resolution such as a serial dot printer. Even if a ROM is used, it is possible to print out with the same quality as a character obtained by developing an outline font into a bitmap.

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

In the second embodiment, the font management unit 4
As shown in FIG. 2, coordinate detection means 4b for detecting the coordinate information of the outline font A in the bitmap conversion coordinates 9 used for bitmap development of the outline font A, and font coordinate information 9a detected by the coordinate detection means 4b. A cutout range determining unit 4 for determining a bitmap cutout coordinate 9b, which is a minimum coordinate range when the outline font A is developed into a bitmap by using
c.

The character generating section 3 develops the outline font 4a into a bitmap within the range of the bitmap cutout coordinates 9b determined by the cutout range determining means 4c to obtain cutout bitmap data B. I have.

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

The cutout bitmap data B normally generated by the character generator 3 is previously stored in the cache ROM 6, and the cutout coordinates 9b corresponding to the cutout bitmap data B are 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 size of bitmap font data for one character is fixed, but in the case of European fonts, even if the point size is determined, the character width C required for each character depends on the character. And the height D is different. As shown in FIG. 3A, the width C1 of the character "m", the width C2 of the character "e", and the width C3 of the character "l" are different from each other, as shown in FIG. like"
The height D1 of the character "m" and the height D3 of the character "l"
And the height D5 of the character "y" are different from each other. If the size of characters is fixed at the point size in the same way as for Japanese fonts, the control will be easy. However, if the capacity per character is large, it will take more time to print out bitmaps and perform other operations, such as cache ROM6. Requires a large memory capacity.

For this reason, in the second embodiment, when the bit map is developed in the minimum range and the character is stored in the cache ROM 6 in advance, the character is stored in the minimum capacity of each character, thereby improving the quality of the character of the print output. It is an object of the present invention to provide a printer device that obtains a high-speed print output by effectively utilizing the capacity of a memory while maintaining a constant value.

The operation is, as shown in FIGS. 4 and 5,
First, the outline font 5a of the character is superimposed 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 to be represented by a straight line. The cutout range determining means 4c calculates the bitmap cutout coordinates 9b, which is the minimum range on the bitmap coordinates of the outline font, based on the font coordinate information 9a. FIG. 4 (A)
FIG. 4B shows the case of “m”, and FIG.
(C) shows the case of "y".

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 bitmap development, bitmap cutout coordinates 9b are written in addition to the character code. When the cache ROM 6 is reproduced, the reproduction means 4d reproduces a bitmap font based on the cutout bitmap data B and the bitmap cutout 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, if the resolution is 400 [dp
i] (dots / inch) When a 12-point character is bitmap-developed, if 12 points are reduced to 1 inch, a bitmap 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 bit-mapped coordinates 9a.
Has been replaced with the coordinates. As shown in FIG. 5 in which the upper left portion of "m" is enlarged, the coordinate detecting means 4b uses the given bitmap coordinates 9 to make a line p of the outline font 5a and a point which can approximate the curved line portion to a straight line. p is detected. Font coordinate information 9 composed of the coordinates of these points and the connection of the points by the coordinate detecting means 4b.
a is detected.

Usually, various processes are performed using the font coordinate information 9a in order to improve the quality of printed output characters. For example, smoothing of the edge part of the character, processing to prevent the lines that make up the character when the point size is small from overlapping, and outline fonts with the same thickness line information attached to the lines that make up the character Then, for example, a process of setting the thickness of three lines constituting the character "3" to have the same number of dots is performed at the level of the font coordinate information 9a.

The cut-out range deciding means 4c decides the bit map cut-out coordinates 9b which is the minimum range for calculating the maximum coordinate and the minimum coordinate from the font coordinate information 9a detected by the coordinate detecting means 4b and forming a bit map. .
The character generation unit 3 performs expansion processing based on the bitmap cutout coordinates 9b to obtain cutout bitmap data B. The cut-out bitmap data B cannot be supplied to the drawing unit 2 as it is, and the reproduction unit 4d of the font management unit 4
The bitmap is required to be reproduced to the bitmap font A, but the processing is speeded up because the bitmap is expanded in the minimum range. In addition, when the cut-out bitmap data B is stored in the cache ROM 6, the effect of a large capacity reduction is obtained. There is. The reproduction means 4d reproduces the data based on the lower left corner which is the minimum value of the bitmap cutout coordinates.

According to the second embodiment, in the case of a proportional font having different widths and heights depending on characters such as European fonts, the cut-out range determining means 4c determines the minimum necessary range for bitmap development and performs bitmap development. Therefore, the extracted bitmap data is stored in the cache ROM in advance, thereby reducing the capacity of the cache ROM 6 and speeding up the printing process, and at the same time as the character obtained by developing the outline font bitmap. This has the effect of maintaining quality.

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

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

Other configurations are the same as those of the first and second embodiments.

The third embodiment will be described in detail. In the first and second embodiments, only the bitmap data is used as the format of the data to be stored in the cache ROM 6. The memory capacity is small even if the bitmap data is used for small point size characters.However, for large point size characters, even if you try to increase the cache hit rate as much as small characters, the memory capacity is limited. Therefore, there is a problem that the effect of the cache cannot be obtained for characters larger than a certain size for the capacity.

For this reason, in the third embodiment, the cache ROM functions effectively regardless of the size of the point size, so that the quality of the printed output is kept constant and the capacity of the memory is effectively utilized to achieve high-speed operation. It is an object of the present invention to provide a printer device capable of obtaining a proper print output.

As shown in the second embodiment, the coordinate detecting means 4b of the font management unit 4 detects font coordinate information 9a corresponding to the resolution and point size of the printing unit 8. Unlike bitmap fonts whose capacity increases in proportion to an increase in the point size, this data has a constant information amount regardless of a change in the point size.

The font coordinate information 9a is stored in the cache R
By storing the outline font 5a from the outline font storage unit 5 and detecting the font coordinate information 9a in the bitmap coordinates 9a by storing the outline font 5a from the outline font storage unit 5 in advance, the print output can be speeded up.

In the font cache information 4a, the fact that the data stored in the cache ROM 6 is font coordinate information is also registered, and in response to this, the character generator 6 develops the bit map data from the font coordinate information 9a. Start processing.

As described above, in the third embodiment, since the cache ROM has not the bitmap data but the coordinate data, even if the character has a large point size, the cache ROM 6 functions effectively and the conventional RAM cache or the like does not. The hit rate that could not be obtained can be maintained, and the print output is kept of high quality because the coordinate information of the font generated during the normal bitmap expansion process of the outline font of the character generator is used for the data in the cache ROM. It has the effect of being able to do things.

[0045]

As described above, according to the present invention, frequently used characters are stored in the cache ROM in advance, and these characters are transferred from the character generator to the drawing unit without undergoing bitmap expansion of the outline font. The time required for outline font expansion can be reduced by supplying bitmap fonts to
Since the bitmap font stored in the character map is a bitmap font obtained by the normal expansion processing of the character generation unit, even if a cache ROM that speeds up the printing output is used, the character obtained by the outline font bitmap expansion is It is possible to provide an unprecedented excellent printer device capable of printing and outputting with no change in quality. Moreover, depending on characters such as European fonts
What are proportional fonts with different widths and heights ?
And the extraction range determination means needs to develop bitmap
Expand to determine the minimum range and expand to bitmap
The processing is fast, and this cutout bitmap data is
By storing in advance in the cache ROM, the cache RO
Reduce M capacity and speed up print processing and out
Characters by bitmap expansion of line font and what
It has the effect of maintaining the same high quality
You.

[Brief description of the 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 bit-mapped coordinates.

3A and 3B are explanatory diagrams showing characteristics of a European font, wherein FIG. 3A shows a character width and FIG. 3B shows a character height.

FIG. 4 shows an example of bit-mapped coordinates, and (A)
Is an explanatory diagram showing the case of “m”, “B” of “l”, and (C) of “y”.

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]

 Reference Signs List 1 upper device 2 drawing unit 3 character generation unit 3a first supply unit 3b second supply unit 3c selection unit 4 font management unit 4a font cache information 4b coordinate detection unit 4c cutout range determination unit 4d reproduction unit 5 outline font storage unit 5a outline font 6 cache ROM 7 image buffer 8 printing unit 9 bit-mapped coordinates 9a font coordinate information 9b bitmap cut-out coordinates 10 printer A bitmap font B cut-out bitmap data C character width D character height

Claims (4)

(57) [Claims] A rendering unit that renders print data from a host device into dot data and renders the image data in an image buffer; a character generation unit that supplies a bitmap font corresponding to characters in the print data to the rendering unit; In a printer device having a printing unit for printing and outputting dot data drawn in the image buffer, the character generating unit can be obtained by an outline font storage unit for storing an outline font and a normal development output of the outline font. A font cache ROM in which a bitmap font is stored 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 together. The outline is stored in the outline font storage unit. A first supply unit that extracts a bitmap font and supplies the bitmap font to the drawing unit by developing the bitmap, and a second supply unit that extracts a bitmap font previously stored in the cache ROM and supplies the bitmap font to the drawing unit. Supply means, and selection means for selecting the first supply means or the second supply means based on the font cache information , wherein the font management unit includes a bit for an outline font.
In the bitmap conversion coordinates used for map development,
Coordinate detection means for detecting coordinate information of an outline font
And the font coordinate information detected by the coordinate detecting means.
To expand outline fonts into bitmaps
Bitmap cutout coordinates, which is the minimum coordinate range of
And a cut-out range deciding means for deciding.
Out within the determined bitmap cutout coordinates
Line fonts can be cut by bitmap expansion.
A printer device for obtaining output bitmap data . Wherein said font management unit, printer apparatus according to claim 1, characterized in that it comprises a reproducing means for reproducing the bit map fonts by using the said cut-out bit map data and the bitmap clipping coordinates. 3. The cache ROM stores the cutout bitmap data normally generated by the character generator in advance, and the font cache information includes the cutout coordinates corresponding to the cutout bitmap data. the printer apparatus according to claim 1 or 2 wherein wherein. 4. The method of claim 1 wherein the cache for ROM, characterized in that the coordinate detection means of the font management section has previously stored font coordinate information generated in the course of the normal development process detection, or 3 A printer device according to claim 1.