JPH08132674A - Print controlling method - Google Patents

Abstract

PURPOSE: To improve the printing quality by once expanding original image data to binary data more fragmented than print resolution, converting it multi- valued data corresponding to the print resolution by averaging it at each matrix corresponding to the resolution, and then printing by using the multi-valued data. CONSTITUTION: Character data stored in an original image data storage area 9 and supplied for printing is more fragmented than print resolution, expanded as bit map data, and stored in a fragmented data storage area 11. Then, the fragmented binary data is averaged to a matrix corresponding to the print resolution, such as, for example each 4 dots, converted to multi-valued data corresponding to the resolution, and stored in a multi-valued data storage area 12. The four dots for forming the multi-valued data are contracted to be converted to one dot, and made correspond to the resolution. Then, the value of the multi-valued data is input to the print dot to form print dot data, stored in a print dot data storage area 13, and used for printing as print data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print control method suitable for printing images such as characters and illustrations output from a word processor or a computer.

[0002]

2. Description of the Related Art Generally, images such as characters and figures output from a word processor or a computer are printed on plain paper, OHP by various printers such as a thermal printer, an ink jet printer and a laser printer which are used as a kind of output device. It is printed on various recording media such as paper, cardboard, postcards, and Christmas cards.

In such a conventional print control method for a printer, original image data such as characters and illustrations output from a word processor or a computer is converted into print data having the same number of pixels as the print resolution, for example, print dots (black).
Is 1 and the non-printing dot (white) is 0, which is the bitmap data of the image (binary image) consisting of binary data.
The value image is used as print data for printing.

In recent years, characters in a word processor or a computer are mainly in an outline font, and according to the print resolution and the size of a character to be printed, image data of a typeface that has been stored in advance is used. Bit map data having the number of pixels corresponding to the print resolution is formed, and print data having a predetermined number of dots required for printing is formed from this bit map data.

[0005]

By the way, recent printers have a range of 300 to 400 dpi (300 per inch).
A printing resolution of about 300 to 400 pixels) is the mainstream, but with a printing resolution of about 300 to 400 dpi, for example, when printing a commonly used character of about 10 points, There was a problem in that the contours of the may become distorted or jagged.

In order to deal with such a problem, the print resolution is subdivided (the number of pixels to be printed per inch is increased) so that the contour of the print image is smoothed and the print quality is improved. However, if the print resolution is subdivided, there are problems that it becomes difficult to manufacture the print head, the economical burden increases, and the power consumption increases.

The present invention has been made in view of these points, and an object of the present invention is to provide a print control method capable of improving print quality without subdividing print resolution.

[0008]

In order to achieve the above-mentioned object, the print control method of the present invention according to claim 1 temporarily expands the original image data into binary data which is subdivided from the printing resolution, and divides the subdivided data. The digitized binary data is averaged for each matrix corresponding to the print resolution to be converted into multi-value data corresponding to the print resolution, and then the multi-value data is used for printing.

The print control method of the present invention according to claim 2 is a print control method for a thermal printer in which the size of dots to be printed can be made variable by controlling the energization time to the thermal head. It is characterized in that the energization time to the thermal head is controlled in correspondence with the multi-valued data converted according to the item 1.

[0010]

According to the print control method of the present invention as defined in claim 1, the original image data is expanded into binary data subdivided from the print resolution, and the binary data is provided for each matrix corresponding to the print resolution. Is averaged to convert into multi-valued data corresponding to the print resolution to form print data. Then, the print data made into this multi-valued data is
Each matrix has the content of forming a dot having a size corresponding to the size of the averaged value, and the average value of the boundary portion between the non-printing portion and the printing portion is another printing portion. Since it tends to be smaller, it is possible to obtain a high-quality printed image having a smooth contour in which dots smaller than other portions are formed in the boundary portion.

According to the print control method of the present invention as defined in claim 2, the original image data is subdivided into two print resolutions.
The binary data is developed, and the binary data is converted into multi-valued data corresponding to the printing resolution by averaging each matrix corresponding to the printing resolution to form the printing data. Then, by controlling the energization time to the print head based on the multi-valued print data, a dot smaller than the other part is formed at the boundary between the non-printing part and the printing part, and the smooth contour is formed. A printed image with a high quality thermal printer can be obtained.

[0012]

The present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 is a system block diagram showing a main part of an embodiment to which a print control method according to the present invention is applied.

As shown in FIG. 1, the system 1 of the present embodiment.
Is a main body 2 such as a word processor or a computer
The main body 2 has at least a thermal printer 3 as a printing unit for recording information such as characters on a recording medium (not shown), a display (not shown), a keyboard, a mouse, and the like. Output devices, etc. are connected.

The main body 2 has at least a CPU 4 and
A main storage device 5 formed by a ROM, RAM, other memory, etc. having appropriate capacities, desired basic data, for example, a character font corresponding to a printing resolution 400 dpi called an outline font (abbreviation of character generator). The external storage device 6 such as an HDD for storing the font data of 1), various application programs, and the like, a printer control board 7 corresponding to the thermal printer 3, and the like are provided.

The main storage device 5 is provided with a control program area 8 occupied by a control program, an original image data storage area 9 for storing an original image to be output, and the like.

In the main memory 5, the original image data stored in the original image data storage area 9 is stored.
What is developed into binary data subdivided from the printing resolution of the thermal printer 3, that is, a subdivided data storage area 11 for storing the subdivided data, and a matrix in which the subdivided binary data corresponds to the printing resolution. A multivalued data storage area 12 for storing the converted multivalued data corresponding to the print resolution by averaging for each, and a print dot corresponding to the subdivided binary data print resolution. A print dot data storage area 13 for storing data of dots to be actually printed which is formed by adding the information of the multi-valued data to the print dots and is provided with the print dot data is provided. .

Further, in the control program area 8, a history data storage area 14 for storing past print patterns of the heating elements 18 of the thermal head 17 as a print head, which will be described later, and the heating elements 18 are provided. A heat storage amount lookup table area 15 in which the relationship between the print pattern and the heat storage amount is stored in advance, and an energization time lookup in which the relationship between the heat storage amount and the energization time corresponding to each value of the multivalued data is stored in advance. A table area 16 is provided.

Further, in the main storage device 5, the print dot data stored in the print dot data storage area 13, the history data stored in the history data storage area 14, and the heat storage amount are further stored. The time to energize each heating element 18 of the thermal head 17 calculated by performing correction using the data stored in the look-up table area 15 and the data stored in the energization time look-up table area 16 A print data storage unit 19 for storing is provided.

Further, the printer control board 7 is provided with a controller 10 for controlling the sending of the print data stored in the print data storage section 19 to the thermal printer 3 and a temporary storage of the print data. Buffer 20 is provided.

The thermal printer 3 supports a recording medium such as a sheet of paper and an ink ribbon coated with a heat-meltable ink on a platen, and generates heat from a thermal head 17 in which a plurality of heating elements are arranged. The element 18 is configured to selectively generate heat based on print data to print an image such as a desired character on a recording medium.

As shown in FIG. 1, the thermal printer 3 has at least a line memory 21 for storing print data sent from the main body 2 in units of print lines, and a print data stored in the line memory 21. An energization control circuit 22 that controls energization of each heating element 18 of the thermal head 17, a thermal head 17 with a printing resolution of 400 dpi, and a mechanism control circuit 23 that controls a mechanism (not shown) of the thermal printer 3 are provided. .

The energization control circuit 22 is provided with at least a comparison arithmetic circuit 24 and an energization control clock transmission section 25.

The thermal head 17 has a printing resolution of 400 dpi (400 dots per inch) connected to at least the head drive circuit 26 and the driving power source 27.
And a plurality of heating elements 18 arranged in an array corresponding to the above, and the head drive circuit 26 is provided with a shift register 28, a latch 29, and a transistor array 30.

Next, an explanation will be given of an example of the character printing control method in the case where the printing resolution of the thermal head is 400 dpi, which is the operation of this embodiment having the above-mentioned construction.

FIG. 2 is a schematic diagram for explaining an example of creating print data.

First, a control command (print command) is issued from the CPU 4 of the main body based on information from an input device (not shown) such as a keyboard, and is stored in the control program area 8 of the main storage device 5. By the control program, character data (specifically, outline font of characters) as original image data to be printed is taken out from the external storage device 6 and stored in the original image data storage area 9 of the main storage device 5. Then, the character data for printing stored in the original image data storage area 9 is calculated by the CPU 4 based on the control program, and the printing resolution (400 dp
i) 800 dp, which is subdivided in this embodiment
It is developed as bitmap data of i (binary binary data of 0 and 1 of 800 dots per inch) and stored in the subdivided data storage area 11. That is, in this embodiment, one dot at the time of printing is doubled in the vertical direction and doubled in the horizontal direction to make a total of four dots, and these four dots are used as a matrix corresponding to the printing resolution.

Next, the binary data subdivided from the print resolution is calculated based on the control program, and the print resolution is obtained by averaging every 4 dots in the matrix corresponding to the print resolution, in this embodiment. Is converted into multivalued data and stored in the multivalued data storage area 12. That is, assuming that the data corresponding to the print dot size in the case of binary printing is 1 by averaging the binary values of 4 dots corresponding to 1 dot in printing, in the present embodiment, 0, 0.25, 0.5, 0.75,
Five-level multivalued data of 1 is formed.

Next, the 4 dots forming the multi-valued data are reduced and converted into 1 dot to make the size of the print dot corresponding to the print resolution, and the value of the multi-valued data is put in this print dot. Thus, print dot data is formed and stored in the print dot data storage area 13.

Next, the relationship between the print dot data, the past print pattern stored in the history data storage area 14, the print pattern previously stored in the heat storage amount look-up table area 15 and the heat storage amount. On the basis of,
The current heat storage amount (temperature of the thermal head 17) of each heating element 18 of the thermal head 17 is calculated.

Next, based on the current heat storage amount of each heating element 18 and the relationship between the heat storage amount corresponding to each value of the multivalued data stored in advance in the energization time lookup table area 16 and the energization time. , Print data corresponding to the energization time is calculated for each print dot corresponding to the print resolution. The print data is stored in the print data storage unit 19.

Next, the print data stored in the print data storage section 19 is sent to the printer control board 7 and the controller 10 of the printer control board 7 is controlled.
Of the line memory 21 of the thermal printer 3 via the buffer 20 in the printer control board 7.
Sent to

Next, in the line memory 21 of the thermal printer 3, the print data sent from the printer control board 7 is stored in print line units.

Next, in the comparison calculation circuit 24 of the energization control circuit 22, the print data stored in the line memory 21 is sequentially compared and calculated with a predetermined threshold value and turned ON / OFF.
It is converted into a signal and sent to the head drive circuit 26. In addition, the energization control clock sending unit 25 of the energization control circuit 22 sends an energization control clock that subdivides the energization line cycle of the heating element 18 to the head drive circuit 26.

Next, in the head drive circuit 26, an ON / OFF signal for each heating element 18 is sent to the shift register 28 by the latch 29 every energization control clock.
From each of the heating elements 1 to the transistor array 30.
8 is heated at a predetermined timing for a predetermined time, and printing is performed on a recording medium (not shown).

Next, a concrete example of a method of creating print data by the print control method of the present embodiment having the above-mentioned configuration will be described with reference to FIG.

FIG. 2 is a schematic diagram for specifically explaining the formation of print data in the case of printing a triangle, (a) is a schematic diagram for explaining a print image, and (b) is a print of the present invention. It is a schematic diagram explaining the bitmap data formed by the control method, (c) is a schematic diagram explaining the print data formed by the print control method of this invention, (d) is a conventional print control method. FIG. 6 is a schematic diagram illustrating bitmap data as print data formed by.

In order to print the triangle (outline) shown in FIG. 2A, in the conventional print control method,
As shown in FIG. 2D, at 400 dpi, which is the same as the print resolution (400 dpi) of the thermal head, the bit map data (binary 2 of 0 (non-printing portion) and 1 (printing portion)) is used.
Value data) is formed, and this 400 dpi bitmap data is used for printing as print data.

In contrast to this conventional method of creating print data, in this embodiment, first, as shown in FIG. 2B, the print resolution of the thermal head 17 (400 dp
Bitmap data (binary binary data of 0 and 1) is formed at 800 dpi which is twice as large as that of i)
By averaging the number of dots corresponding to one dot at the time of printing, a binary value in a matrix of 4 dots in this embodiment, for example, (1, 1, 1, 0) from the bitmap data of Multivalued data of 0.75 is formed. Next, as shown in FIG. 2 (c), a matrix of 4 dots corresponding to 1 dot at the time of printing is converted into 1 dot so as to correspond to the printing resolution, and a multivalue of 0.75 is added to this dot. By adding data as an attribute value, a print dot having a size of 0.75 is formed and used for printing.

That is, in the present embodiment shown in FIG. 2 (c), dots smaller than other portions are arranged at the boundary portion between the printing portion and the non-printing portion, and the dot is shown in FIG. 2 (d). As compared with the conventional example shown in FIG. 2, the shapes can be made more similar to the shapes to be actually printed, which are shown by broken lines in FIG. 2C and FIG. It is possible to obtain a smooth, high-quality printed image.

Although the dots are shown separated in FIG. 2 for the sake of explanation, when viewed from the actual printing result in the thermal printer 3, the dots are connected and the small dots are large due to the heat distribution. Since the printing is performed at a position closer to the side, it is possible to make the shape more similar to the shape to be actually printed.

In FIG. 2C, the dot printing size is changed by adjusting the energization time of one energizing pulse for each dot to change the dot printing size. It is also possible to change the size of dot printing by adjusting the number of energizing pulses for energizing the dots. It is also possible to change the size of dots to be printed by changing the value of the applied voltage or current.

Furthermore, in this embodiment, 800
When the bitmap data of dpi is set to the print data of 400 dpi, the same thick line as shown in (a) of FIG. 3 may be obtained depending on the position (coordinate) of the dot segmented as 800 dpi in the original image data. It becomes a double line consisting of 1 dot horizontal line, or as shown in FIG. 3B, one thick 1 dot horizontal line and half the thickness of the thick dots located above and below this 1 dot horizontal line. There are three main lines consisting of 0.5 dot horizontal lines. In order to obtain good print quality, it is necessary to control these so that they have the same thickness to the human eye. In view of this, in the present embodiment, in the above case, the energy of each heating element 18 (the energization time of the drive current to each heating element 18) is visually observed by the human eye as having the same thickness in the above case. To control.

More specifically, in the thermal printer 3, 0, 0.25, 0.5, 0.75,
For print data having multi-valued data of 5 levels of 1,
The energizing time is not determined by 1: 1 respectively,
When each print data is used for printing, the heat storage element 18 which is energized based on the print data stores the heat immediately before the heat generating element 18 which prints the print data depending on the duty of printing in the previous history. The amount of heat (the temperature of the thermal head 17) is obtained, and the relationship between the heat storage amount and the actually required energization time of the heating element 18 is the heat storage amount lookup table area 15 as a lookup table.
The lookup table is tuned by experiment so that the line thickness approximates to the original image data and is used.

It is also possible to change the matrix setting positions to a plurality of positions, perform actual printing, and select the matrix setting position according to the printing purpose from the printing results.

In this embodiment, 400 dpi
Although the original image data of 800 dpi is 800 dpi bitmap data that is twice as large in both vertical and horizontal directions, the resolution of the bitmap data only needs to be larger than the printing resolution of the thermal head that actually performs print output. In particular, the bitmap of this embodiment is used. It is not limited to the data resolution value. Further, the resolution of the bitmap data does not have to have an aspect ratio of 1: 1.

Further, in the present embodiment, the character data is described as an example, but image data such as an illustration formed or edited on the display or the like can be printed in the same manner.

Further, in the present embodiment, the thermal printer 3 has been described as an example of the printing means, but the size of the dots to be printed by controlling the energizing time, the voltage value, the current value, etc. when the head is driven. Of course, the present invention can be applied to a printer having a print head capable of changing the print head, such as an inkjet printer, a laser beam printer, or the like.

Further, the present invention is not limited to the above-mentioned embodiment, but can be modified as necessary.

[0050]

As described above, according to the print control method of the present invention, the print resolution of the print head is not subdivided, and the boundary between the print portion and the non-print portion is smaller than other print portions. It has an extremely excellent effect that dots can be arranged and a high-quality printed image having a smooth contour can be surely obtained.

[Brief description of drawings]

FIG. 1 is a system block diagram showing a main part of an embodiment to which a print control method according to the present invention is applied.

2 (a) to (d) are schematic diagrams for specifically explaining formation of print data when printing a triangle.
(A) is a schematic diagram illustrating a printed image, (b) is a schematic diagram illustrating bitmap data formed by the print control method of the present invention, and (c) is a print formed by the print control method of the present invention. Schematic diagram for explaining the data, (d) is a schematic diagram for explaining the bitmap data as the print data formed by the conventional print control method.

3 (a) and 3 (b) show a case where the bitmap data subdivided from the print resolution is set as print data having the same resolution as the print resolution without controlling, and FIG. Is a schematic diagram for explaining the case where it becomes, and (b) is a schematic diagram for explaining the case where there are three main lines.

[Explanation of symbols]

 1 System 2 Main Unit 3 Thermal Printer 4 CPU 5 Main Storage Device 6 External Storage Device 7 Printer Control Board 8 Control Program Area 9 Original Image Data Storage Area 11 Subdivision Data Storage Area 12 Multi-value Data Storage Area 13 Print Dot Data Storage Area 17 Thermal head 19 Print data storage 21 Line memory 22 Energization control circuit

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H04N 1/40 B41J 3/20 115 D H04N 1/40 103 B

Claims (2)

[Claims] 1. An original image data is once developed into binary data subdivided from the printing resolution, and the subdivided binary data is averaged for each matrix corresponding to the printing resolution to obtain a multivalue corresponding to the printing resolution. A printing control method, comprising converting into value data and then printing using the multivalued data. 2. A print control method for a thermal printer capable of varying the size of dots to be printed by controlling the energization time to the thermal head, the thermal control method corresponding to multi-valued data converted according to claim 1. A printing control method characterized by controlling an energization time to a head.