JP3033501B2 - Dot printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dot printer, and more particularly to a dot printer for thinning out dot data for printing at a speed higher than that for printing dot data at a normal speed, for example, double speed or triple speed. (Dot matrix printer).

[0002]

2. Description of the Related Art In a conventional dot matrix type printer, a dot data thinning processing method for performing high-speed printing at double speed or triple speed in addition to a normal printing speed is disclosed in Japanese Patent Application Laid-Open No. 60-206666. There is a disclosed technique. In this method, dots to be thinned out are determined from dot data to be printed at a normal speed, depending on how dots are arranged in the horizontal direction. In this method, a thick vertical line composed of a row of two horizontal dots is converted into a thin line composed of a row of one horizontal dot.

Japanese Patent Application Laid-Open No. 07-052464 discloses that bitmap font data different from that used when printing at normal speed is created and stored in order to control the deterioration of the print quality of dot data after thinning. A technique for performing this is disclosed.

[0004]

However, in the prior art, when dot data to be used for printing at double speed or triple speed is created, horizontal dot arrangement is performed based on dot data when printing at normal speed. When dot data thinning processing for printing at double speed or triple speed is performed in order to perform thinning processing in consideration of only the above, a thick vertical line composed of a row of two horizontal dots is composed of a row of one horizontal dot. There is a disadvantage that it becomes a thin line.

[0005] Further, no consideration is given to preventing the print quality from deteriorating in the thinning-out process, and it is necessary to prepare dot data on the premise of the thinning-out process. In addition, when printing at double speed or triple speed is attempted, there is a disadvantage that the memory capacity for storing dot data increases.

[0006]

An object of the present invention is to improve the disadvantages of the prior art, and in particular, to increase the memory capacity required for storing dot data and reduce the print quality of dot data at 2x or 3x speed. It is an object of the present invention to provide a dot printer which can perform high-speed printing.

[0007]

Therefore, according to the present invention, there is provided editing means for editing print data transmitted from a host device into dot data, and printing means for printing dot data output from the editing means. ing. Moreover, editing means, and the dot extraction unit for extracting a successive dots constituting the lines of the print data, extracted by the dot extraction unit
If the drawn line has a thickness of 2 dots or more, the thickness
Alternate in the thickness direction while leaving the dots at the ends of the
The dots in the direction of travel of the line
And a thinning unit . This aims to achieve the above-mentioned object. When the dots are thinned out by the dot thinning unit, the dots are thinned out while maintaining the thickness of the line as in the example of the vertical line shown in FIG.

In the present invention, the dot data subjected to the thinning process for double speed or triple speed printing is dot data for printing at normal speed, and a thick vertical line composed of a row of two horizontal dots is used. When it is recognized as a vertical line, it is recognized as a thick vertical line composed of two horizontal dots,
The printing quality is not extremely reduced. For this reason, it is not necessary to prepare in advance dot data dedicated to the thinning process in consideration of the deterioration of the print quality of the dot data after the thinning process, and therefore, the memory capacity for storing the dot data does not increase.

[0009]

Next, embodiments of the present invention will be described with reference to the drawings. The dot printer includes an editing unit that edits print data transmitted from a host device into dot data, and a printing unit (printing unit) that prints dot data output from the editing unit. In addition, the editing means includes a dot extracting unit for extracting continuous dots forming the line of the print data, and a dot thinning unit for thinning out the dots in the thickness direction of the line extracted by the dot extracting unit alternately in the traveling direction of the line. Section.

The dot extracting section extracts continuous dots forming a line. Usually, the deterioration of the character quality is a problem in the Roman system, for example, the Mincho type. Therefore, in the present embodiment, the case where the photo data is the Mincho type will be described as an example.
In the case of Mincho, a line composed of two dots is a vertical line. For this reason, in the present embodiment, the processing of the dot extraction unit is to extract vertical lines. Further, in the case of realizing the double speed by printing every other dot, it is necessary to thin out one of two consecutive dots in the horizontal direction. For this reason, in the present embodiment, as shown in FIG. 1, the vertical direction thinning processing unit 7 and the horizontal direction thinning processing unit 8 realize a dot extracting unit and a dot thinning unit.

As shown in FIG. 1, the dot printer according to the present embodiment includes an overall control unit 1 for controlling the overall operation and processing, a dot data storage unit 2 including a storage device 6 for storing dot data, A thinning processing unit 3 for thinning dot data in accordance with a printing speed, a print control unit 4 for reading dot data from a dot data storage unit 2 in accordance with a print command from the general control unit 1 and performing a printing operation; A print speed determining unit 5 for determining whether to print at a normal speed, a double speed, or a triple speed in accordance with predetermined conditions such as a speed designation from the unit 1 and dot data density.

The thinning-out processing unit 3 extracts three consecutive dots in the vertical direction and, among the three dots, a vertical thinning-out processing unit 7 that thins out the central dot, and extracts two consecutive dots in the horizontal direction. And a horizontal thinning-out processing unit 8 for thinning out one of two consecutive dots. This 2
If one of the consecutive dots is thinned out, double speed printing becomes possible.

Further, the horizontal thinning processing section 8 has a triple speed thinning function for extracting two of the three dots in the horizontal direction and thinning one of the two dots. If this triple-speed thinning function is repeatedly executed, triple-speed printing can be performed.

Print speed determination unit (print speed determination means) 5
Determines the operation speed set for the printing unit. Then
The horizontal thinning-out processing unit 8 selects double speed or triple speed thinning processing based on the printing speed determined by the printing speed determining unit (thinning selection function).

Next, the operation of this embodiment will be described.

First, dot data to be printed in the storage device 6 is stored in the dot data storage section 2. Next, the printing speed determining unit 5 determines the printing speed to be one of the normal speed, double speed, and triple speed. Here, when the double speed or the triple speed is selected, the thinning processing unit 3 performs the thinning process. The thinned dot data is stored in the storage device 6. Further, the print controller 4 reads out the dot data stored in the storage device 6 and drives a print head pin corresponding to the dot data to obtain a desired print result.

[0017]

Next, embodiments of the present invention will be described with reference to the drawings. The vertical thinning processing unit 7 determines whether or not to perform thinning of a certain dot based on the continuity of dots in the vertical direction of the dot data.

Here, the vertical direction is the reference numeral 2 in FIG.
2. As an example, as a result of examining three consecutive dots in the vertical direction, as shown in FIG. 2A, when all three dots have a dot, the vertical thinning processing unit 7 removes the central dot. The result of the thinning is 10. When the thickness of the line is represented by two dots, the vertical thinning processing unit 7 thins out the left dot, and the horizontal thinning processing unit 8 thins out the right dot, so that the line alternates in the traveling direction of the line. Thinning is performed.

The horizontal thinning processing unit 8 determines whether or not to perform thinning of a certain dot based on the continuity of dots in the horizontal direction of the dot data. Here, the horizontal direction refers to FIG.
In the direction indicated by reference numeral 21. For example, in order to create dot data suitable for double speed printing, if two dots are consecutive as indicated by reference numeral 14 in FIG.
A process for thinning out the right dots as shown in FIG.

In order to create dot data suitable for triple speed printing, when there is a dot at the left end as shown by reference numeral 17 in FIG. Here, the conversion is performed as shown in FIG.

Next, the operation of the embodiment of the present invention will be described.
The storage device 6 shown in FIG.
24 dot data is stored. However,
The size of the dot data does not need to be fixed to 24 × 24 dots, but is variable as needed. Next, this 24 × 2
As shown in FIG. 4, each dot of the four dot data is represented by A
(0,0) is assigned to A (23,23) one dot at a time.

Next, the printing speed is determined by the printing speed determination unit 5. When the printing speed is determined to be double speed, the thinning processing section 3 performs the following thinning processing.

First, for a certain dot data A (m, n), in order to check the continuity of dots in the vertical direction, the upper dot A (m-1, n) and the lower dot A (m + 1, n) are checked. The presence or absence of a dot is checked to determine whether or not A (m, n) is thinned. Here, a condition is adopted that if there are upper and lower dots, thinning is performed. If this is expressed by a logical expression, a logical expression (1) is obtained. This processing is performed by the vertical thinning processing unit 7.

A (m, n) = not (A (m−1, n)) and (not (A (m, n))) and (not (A (m + 1, n))) (1) )

As shown in FIG. 2A, in the case of three consecutive dots 9 in the vertical direction, the result of thinning out the center dot is 1
0, and for other combinations 11,
In 12 and 13, it is left as it is.

Next, in order to check the continuity of dots in the horizontal direction of A (m, n), the adjacent dot A (m, n−
The presence or absence of the dot of 1) is checked, and it is determined whether or not A (m, n) is thinned. Here, the logical expression (2) is used by adopting the condition that if there is a dot on the left side, thinning is performed. This processing is performed by the horizontal thinning processing unit 8.

A (m, n) = not (A (m, n−1)) and A (m, n) (2)

As shown in FIG. 2B, when two consecutive dots 14 are arranged horizontally, the conversion is performed as shown by a result 15 obtained by thinning out the right dot.
Then let it be.

As described above, a certain dot A (m,
When the thinning determination processing for n) is completed, A (m
By performing the same thinning process on (+1, n), A (0, 0) to A (23, 0), then A
A from (0,1) to A (23,1)
The thinning-out determination process is performed on all the dots from (0,0) to A (23,23).

The resulting dot data is shown in FIG.
(B), the dot data is dot data suitable for double-speed printing of the dot data.

Next, a description will be given of a thinning process in the case where triple speed printing is selected by the printing speed determination unit 5.

First, with respect to certain dot data A (m, n), in order to check the continuity of dots in the vertical direction, the upper dot A (m-1, n) and the lower dot A (m + 1, n) are checked. The presence or absence of a dot is checked to determine whether or not A (m, n) is thinned. Here, a condition is adopted that if there are upper and lower dots, thinning is performed. This can be expressed by a logical expression (4). This processing is performed by the vertical thinning processing unit 7.

A (m, n) = not (A (m−1, n)) and (not (A (m, n)) and (not (A (m + 1, n))... (4)

As shown in FIG. 2A, when the dot 9 is three dots vertically continuous, the result of thinning out the center dot is 1
0, and for other combinations 11,
In 12 and 13, it is left as it is.

Next, in order to check the continuity of dots in the horizontal direction of A (m, n), the dot A (m, n-
2), the presence or absence of the dot of A (m, n-1) is checked;
It is determined whether (m, n) is thinned out. Here, the logical expression (5) is used by adopting the condition that if any one of the two dots on the left side has a dot, it is thinned out. This processing is performed by the horizontal thinning processing unit 8.

A (m, n) = not (A (m, n)) and not (A (m, n−1)) and A (m, n)... (5)

As shown in FIG. 2 (C), when the dot 14 consists of three horizontal dots, the result is converted as a result 18 obtained by thinning out the two dots on the right side. Leave as is.

As described above, a certain dot A (m,
When the thinning determination processing for n) is completed, A (m
By performing the same thinning process on (+1, n), A (0, 0) to A (23, 0), then A
A from (0,1) to A (23,1)
The thinning-out determination process is performed on all the dots from (0,0) to A (23,23). The dot data obtained as a result is as shown in FIG. 3C, which is dot data suitable for dot data triple speed printing.

Next, a second embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 5, the dot printer according to the second embodiment stores, as a table, a dot pattern in which dots in the line thickness direction are alternately thinned in the line traveling direction for each 3 × 3 dot block. And a block replacement unit 31 that replaces the bitmap data with a table for each block.

In the case of this configuration, in the dot data array shown in FIG. 2, the thinning-out determination is not performed for a certain dot, but is performed for each 3 × 3 dot block, for example. More specifically, for all of the 256 combinations of 3 × 3 dots, it is determined in advance how to convert the combinations, and the combinations are stored as table data. This table data needs to be prepared for each of double speed and triple speed.

In this way, the dot data stored in the storage device 30 is divided into 3 × 3 dot blocks, and a suitable pattern is searched for from the table data corresponding to the speed designation, and is converted into the conversion result at that time. For example, FIG.
In the case of the dot data array of reference numeral 32 shown in FIG.
Is converted to the pattern shown in

As described above, according to the present embodiment, the following effects can be obtained. The first effect is that even if the thinning process is performed to create dot data suitable for 2 × speed and 3 × speed printing, a thick vertical line composed of a row of 2 horizontal dots is generated.
The entire vertical line can be recognized as a thick vertical line composed of a row of two horizontal dots. The reason is that since the thinning process is performed in consideration of the dot arrangement in the vertical direction and the horizontal direction, all the one dot lines of the horizontal two dot lines constituting the vertical line are not thinned out and the dots remain alternately. is there.

The second effect is that when printing at double speed and triple speed is performed, the memory capacity for storing dot data is not different from that at normal speed printing. The reason is that it is not necessary to prepare dot data for the thinning process in order to perform the thinning process in consideration of not deteriorating the print quality.

[0044]

The present invention is constructed and functions as described above. According to this, according to this, the dot extracting unit extracts continuous dots constituting a line of print data, and the dot thinning unit extracts the continuous dots by the dot extracting unit. Since the dots in the direction of the thickness of the drawn line are thinned alternately in the traveling direction of the line, the thinning process for high-speed printing can be performed without changing the thickness of the line.
By performing this process on normal font data, it is possible to maintain a certain level of quality, so there is no need to create or store font data specially for high-speed printing. The present invention provides an unprecedented excellent dot printer capable of performing high-speed printing at double speed or triple speed without increasing the memory capacity required for printing and without lowering the print quality of dot data.

[Brief description of the drawings]

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

2A and 2B are explanatory diagrams showing a combination of dots and a pattern after thinning out. FIG. 2A is a diagram showing a combination of three vertical dots, and FIG. 2B is a diagram showing a combination of two horizontal dots. FIG. 2C is a diagram showing a combination of three horizontal dots.

FIG. 3 is an explanatory diagram showing an example of dot data for printing. FIG. 3 (A) is a diagram showing dot data for normal speed printing, and FIG. 3 (B) is a diagram showing dot data for double speed printing. FIG. 3C is a diagram showing dot data for triple speed printing.

FIG. 4 is an explanatory diagram showing an array of dot data.

FIG. 5 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a conversion example of a 3 × 3 dot block used in the embodiment shown in FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Overall control unit 2 Dot data storage unit 3 Thinning processing unit 4 Printing control unit 4B printing unit 5 Printing speed determination unit 6 Storage device 7 Vertical thinning processing unit 8 Horizontal thinning processing unit 9 Vertical 3 dot continuous dots 10 Center 11 Do not thinned out 12 Do not thinned out 13 Do not thinned out 13 Do not thin out 14 Double 2 dots continuous 15 Dot thinned out right 16 Do not thinned out 17 Horizontal 3 dots continuous 18 Non-thinned combinations 19 Non-thinned combinations 21 Horizontal direction 22 Vertical direction 32 3 × 3 dot combination example 33 3 × 3 dot conversion example

Continuation of front page (56) References JP-A-4-7166 (JP, A) JP-A-64-14049 (JP, A) JP-A-63-116858 (JP, A) JP-A-63-116859 (JP, A) JP-A-8-174909 (JP, A) JP-A-63-120663 (JP, A) JP-A-5-301378 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B41J 2/485 B41J 2/51 H04N 1/40

Claims (5)

(57) [Claims] 1. A dot printer comprising editing means for editing print data transmitted from a host device into dot data, and printing means for printing dot data output from the editing means, wherein the editing means comprises: dot extraction unit for extracting a successive dots constituting the lines of the print data, to the dot extraction unit
If the extracted line has a thickness of 2 dots or more,
In the thickness direction, leaving the dots at the end in the thickness direction
While thinning out the dots in the traveling direction of the line in an alternating state
Dot printer, characterized in that a dot thinning unit pulling. 2. A dot printer comprising editing means for editing print data transmitted from a host device into dot data, and printing means for printing dot data output from the editing means, wherein the editing means comprises: A vertical thinning-out processing unit that extracts three consecutive dots in the vertical direction and thins out the central dot among the three dots, and further extracts one of the two consecutive dots in the horizontal direction and further adds one of the two consecutive dots Docks next to
A horizontal thinning-out processing section for thinning out by referring to the presence / absence of the dot printer. 3. The apparatus according to claim 1, wherein the horizontal thinning-out processing unit is configured to execute a horizontal thinning process.
3. The dot printer according to claim 2, further comprising a triple-speed thinning-out function for extracting a dot including two of the dots and thinning out one of the two dots. 4. A printing speed judging unit for judging an operation speed of the printing unit is provided in the editing unit. 4. The dot printer according to claim 3, further comprising a thinning selection function for selecting a thinning process. 5. A dot printer comprising editing means for editing print data transmitted from a host device into dot data, and printing means for printing dot data output from the editing means, wherein the editing means comprises: Alternating in the line thickness direction while leaving the dot at the end in the line thickness direction for each 3 × 3 dot block.
A table storage unit for storing, as a table, a dot pattern in which dots are thinned out in a line traveling direction in a state where the dot map is drawn, and a block replacement unit for replacing the bitmap data with the table for each block. Printer.