JPH11115165A - Ink-jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate empty discharge during letter code printing and to improve an ink consumption efficiency a printing speed by a method in which in the longitudinal bit string of a printing buffer, a bit corresponding to the uppermost part nozzle of a print head is constituted from a means which does not fix to the uppermost part bit. SOLUTION: The uppermost part bit in a printing area 21 of first line 32 dot width is correspondence-printed to the uppermost part nozzle, 8 nozzles in the lower part corresponding to a blank area 22 of 8 bits are not used. The lowest dot of the second line area 23 is correspondence-printed in the lowest part nozzle. Since the lowest part nozzle of lowest dot position of the first line area 23 is at the lowest part dot position of the area 23, the line change quantity 27 of the second line transfer is a 32 dots portion. In the third line, similar to the first line, the uppermost dot of the area 25 is correspondence- printed in the uppermost part nozzle, the line change quantity 28 from the second line to the third is a 48 dots portion added with nozzle line portion 40 dots to 48 dots of a blank area portion. By repeating it, printing using all the nozzles is made.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printing method for a printer using an ink jet system.

[0002]

2. Description of the Related Art Printers are widely used as devices for recording information output from OA equipment, and one of such systems is an ink jet system. FIG. 7 shows the appearance of the ink jet head. Ink is ejected from each nozzle of the nozzle row 3 arranged on the nozzle plate 2. FIG.
FIG. 4 is a schematic diagram illustrating a state of a printing operation. The printing is performed by scanning the print head 1 on the print medium, controlling the timing at which ink is ejected from each nozzle, and sending the print medium at the end of each scan.

A conventional example of a printing operation when only a character code is transmitted from a host computer will be described below in a case where the maximum height of a built-in character is 32 dots. FIG. 9 shows an example of dot arrangement of built-in characters. A ROM incorporating such dot arrangement information as bit data for all characters is hereinafter referred to as a CG-ROM.

FIG. 10 is a diagram showing the correspondence between the dot arrangement of characters and the nozzles of the head. Since blanks, underlines, and ruled lines may appear between lines in actual sentences, the number of nozzles in the print head is larger than the number of bits in the height direction of the bit image of the built-in characters, and the pitch of each line in the default setting Equal to the number of corresponding dots. In the conventional example, the number of nozzles was 40.

The print buffer 5 is a RAM having a length of 40 bits corresponding to each of the 40 nozzles and a number of bits equal to the number of horizontal dots that can be placed on a print medium. . Each bit in one vertical column of the print buffer is data indicating whether to drive a corresponding nozzle. After driving one column of bit data corresponding to the nozzle, the next drive moves to the next column in the scanning direction, and the bit data of that column is driven again corresponding to the nozzle.
In this way, the data in the print buffer is printed.

[0006] The host computer transmits the control code to the printer to cause the printer to work. Among the control codes, information which is an element for actually forming dots on a print medium is printed with graphics. Bit data and character codes. The character code is a one-byte or two-byte code for designating a certain character. Upon receiving the character code, the printer reads the bit image of the specified character from the CG-ROM and writes the bit image to the print buffer.

FIG. 6 is a diagram showing a state in which print data of each line is written in a print buffer in a conventional example. In the print buffers 12, 13, and 14, the bit images of the built-in characters are written in the upper 32-bit data areas 15, 17, and 19. If there are no graphics or ruled lines, the lower 8-bit data areas 16, 17, 18 remain blank. When the print buffer is written up to the paper feed code or the end of the line, the contents of the print buffer are printed on the print medium by the print head. FIG. 5 is a diagram showing a state where characters are recorded on a print medium by a conventional printing operation. Areas 6, 8, and 10 are 32-bit print areas. Areas 7, 9, and 11 are 8-bit blank areas. The blank area corresponds to the lower eight nozzles of the nozzle row 3. 1
After the printing of the line is completed, the print medium is fed by 40 dots. If printing continues in the subsequent rows in the same manner, since the lower 8 bits of the print buffer are always blank, a state in which ink droplets are not ejected from the lower 8 nozzles of the print head continues for a long time.

[0008] In this case, the ink surface of the nozzle that has not been ejected remains in contact with air for a long time, causing a state change such as drying or thickening of the ink inside the vicinity of the ink surface. This causes a phenomenon that the ink droplets are hardly ejected from the ink, and the size of the ink droplets changes. In order to solve this, conventionally, there has been a means for periodically discharging a predetermined amount of ink droplets not related to printing. This means is hereinafter referred to as idle discharge.

[0009]

However, the conventional method described above consumes ink wastefully,
The problem of low ink consumption efficiency,
There has been a problem that the printing operation is temporarily stopped due to the idle discharge operation, and the printing speed is reduced.

In order to solve the above problems, an object of the present invention is to provide an ink jet printer which eliminates idle ejection at the time of printing a character code, thereby improving ink consumption efficiency and printing speed.

[0011]

In order to achieve the above-mentioned object, the present invention provides a print buffer comprising:
The bit is not fixed to the uppermost bit corresponding to the uppermost nozzle of the print head.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described for a case where the height of a built-in character is 32 dots, the number of head nozzles is 40, and the initial line feed amount is 40 dots.

FIG. 1 shows the printing operation of the first embodiment.
FIG. 3 is a diagram illustrating a state where characters are recorded on a print medium.
On the first line, the uppermost dot in the print area 21 having a width of 32 dots is printed in correspondence with the uppermost nozzle. The eight nozzles below the nozzles corresponding to the 8-bit wide blank area 22 are not used.

In the second line, the lowermost dot in the print area 23 is printed in correspondence with the lowermost nozzle. Therefore, 1
The lowermost nozzle located at the position of the lowermost dot of the blank area 22 on the line must be located at the lowermost dot position of the print area 23 on the second line. That is, the line feed amount 27 when shifting from the first line to the second line is 32 dots for the print area. In the printing of the second line, the bottom eight nozzles not used in the first line are used, and instead the top eight nozzles are not used corresponding to the blank area 22.

In the third line, similarly to the first line, the print area 25
The uppermost dot is printed in correspondence with the uppermost nozzle. Line feed amount 28 when shifting from the second line to the third line
In the third row, the bottom nozzle located at the bottom dot position of the print area 23 in the second row must be located at the bottom dot position of the blank area 26 in the third row.
This is equivalent to 48 dots obtained by adding 40 dots for the nozzle row to the dots. By repeating the above printing operation continuously, printing using all the nozzles is performed.

FIG. 2 is a diagram showing how the print data of each line is written in the print buffer in the first embodiment. The bit image of the built-in character is written in the upper 32-bit data area 32 of the print buffer 29 on the first line. The lower 8-bit data area 33 is blank. In the print buffer 30 on the second line, the bit image of the built-in character is written in the lower 32-bit data area 35. Top 8
The bit data area 34 becomes blank. The third line writes the bit image of the built-in character in the upper 32-bit data area 36 of the print buffer 31 in the same manner as the first line.
The bit data area 37 becomes blank.

A second embodiment of the present invention will be described for the case where the height of the built-in character is 32 dots, the number of head nozzles is 40, and the initial line feed amount is 40 dots.

FIG. 3 is a diagram showing a state in which characters are recorded on a print medium by a printing operation in the second embodiment. In the first row, printing is performed with the uppermost nozzle of the nozzle row 3 corresponding to the uppermost dot. At this time, 8
No nozzle is used.

On the second line, the uppermost dot of the print data is printed in correspondence with the fifth nozzle of the nozzle row 3. As a result, the upper four nozzles corresponding to the upper blank area 42 in the second row and the lower four nozzles are not used. The line feed amount 44 when shifting from the first line to the second line is 36 dots which is smaller by 4 dots of the blank area 42 than the initial line feed amount. .

In the third line, the lowermost dot of the print data is printed in correspondence with the lowermost nozzle. At this time, the upper eight nozzles corresponding to the upper blank area 43 in the third row are not used. Line feed amount 45 when shifting from the second line to the third line
In the third row, the lowermost nozzle located at a position four dots below the lowermost dot of the print data in the second row must be located at the lowermost dot position of the print data in the third row. This is 36 dots, which is 4 dots smaller than the dot.

On the fourth line, as in the first line, the uppermost dot of the print data is printed in correspondence with the uppermost nozzle. 3
The line feed amount 46 at the time of shifting from the line to the fourth line is such that the lowermost nozzle located at the position of the lowermost dot of the print data in the third line is located at the lowermost dot position of the nozzle array area 41 in the fourth line. Since it is indispensable, there are 48 dots obtained by adding 40 dots for the nozzle array to 8 dots for the blank area 43. Second, in the second embodiment, printing is performed using all nozzles by continuously repeating the above printing operation.

FIG. 4 is a diagram showing a state in which print data of each line is written into a print buffer in the second embodiment. A 32-bit bit image of a built-in character is written in the upper part of the print buffer 47 on the first line. The data area of the lower 8 bits is blank. Second line print buffer 4
In step 8, a 4-bit blank area is generated at the top, and a 32-bit built-in character bit image is written below it. The data area of the lower 4 bits is also blank. In the print buffer 49 on the third line, the bit image of the built-in character is written in the lower 32-bit data area. Top 8
The bit data area 43 becomes blank. The fourth line is packed at the top of the print buffer 50 in the same way as the first line,
Write a 2-bit bit image.

The printing operation for using all the nozzles may be other than two or three lines as in the above embodiment. Further, the number, pitch, and initial line feed amount of the nozzles are not limited to those of the embodiment. Of course, it does not specify the font of the character or the number of dots formed in the bit image.

[0024]

According to the present invention, during continuous printing of only character codes, the bits corresponding to the nozzles of the print head are not fixed to the uppermost bits in the vertical bit sequence of the print buffer, thereby eliminating the idle discharge operation. This has the advantage that the ink consumption efficiency and the printing speed are improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a state in which characters are recorded on a printing medium by a printing operation according to the first embodiment.

FIG. 2 is an explanatory diagram of a state in which print data of each line is written into a print buffer according to the first embodiment.

FIG. 3 is an explanatory diagram of how characters are recorded on a printing medium by a printing operation according to the first embodiment.

FIG. 4 is an explanatory diagram of a state in which print data of each line is written into a print buffer according to the first embodiment.

FIG. 5 is an explanatory view of a state in which characters are recorded on a print medium by a conventional printing operation.

FIG. 6 is an explanatory diagram of a state in which print data of each line is written to a print buffer in the related art.

FIG. 7 is a diagram illustrating an appearance of an inkjet head.

FIG. 8 is a schematic view illustrating a printing operation performed by an inkjet printer.

FIG. 9 is a diagram illustrating an example of a dot arrangement of characters in a printer.

FIG. 10 is a diagram showing a correspondence between a dot arrangement of a character and a nozzle of a head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Print head 2 Nozzle plate 3 Nozzle row 4 Print medium 5 Print buffer 6 Print area of first line print result in conventional example 7 Blank area of first line print result in conventional example 8 Second line print in conventional example Result print area 9 Blank area of print result of second line in conventional example 10 Print area of print result of third line in conventional example 11 Blank area of print result of third line in conventional example 12 First line of conventional example 13 print buffer for the second line in the conventional example 14 print buffer for the third line in the conventional example 15 print area for the print buffer for the first line in the conventional example 16 blank area for the print buffer for the first line in the conventional example 17 Print area of second line print buffer in conventional example 18 Blank area of second line print buffer in conventional example 19 Third line in conventional example Print buffer print area 20 blank area of the third line print buffer in the conventional example 21 print area of the first line print result in the first embodiment 22 blank area of the first line print result in the first embodiment Area 23 Print area of the print result of the second line in the first embodiment 24 Blank area of the print result of the second line in the first embodiment 25 Print area of the print result of the third line in the first embodiment 26 Blank area of print result of third line in first embodiment 27 Line feed amount when shifting from first line to second line in first embodiment 28 Second to third line in first embodiment Line feed amount at the time of shifting to 29 29 Print buffer for the first line in the first embodiment 30 Print buffer for the second line in the first embodiment 31 Print buffer for the third line in the first embodiment 32 First In the embodiment Print area of the print buffer in the first line 33 Blank area of the print buffer in the first line in the first embodiment 34 Print area of the print buffer in the second line in the first embodiment 35 Second line in the first embodiment The blank area of the print buffer on the third line in the first embodiment 37 The blank area of the print buffer on the third line in the first embodiment 38 The printing of the first line in the second embodiment Resulting nozzle array area 39 Nozzle array area of the second row printing result in the second embodiment 40 Nozzle array area of the third row printing result in the second embodiment 41 Fourth row in the second embodiment Nozzle array area of the print result 42 Upper blank area of the print result of the second row in the second embodiment 43 Upper blank area of the print result of the third row in the second embodiment 44 One row in the second embodiment Line feed amount when shifting from the second line to the second line 45 Line feed amount when shifting from the second line to the third line in the second embodiment 46 Shift from the third line to the fourth line in the second embodiment Line feed amount at the time 47 Print buffer for the first line in the second embodiment 48 Print buffer for the second line in the second embodiment 49 Print buffer for the third line in the second embodiment 50 In the second embodiment 4th line print buffer

Claims (1)

[Claims] 1. A ROM containing character bit image data, and a print head in which more nozzles than the number of dots in the height direction of the built-in character are arranged in parallel in the height direction of the built-in character. In the case where the print data of only the character code is continuously printed on a plurality of lines, the uppermost dot of the built-in character and the nozzle corresponding thereto are changed for each print scan, and all the nozzles are scanned in a plurality of scans. An ink jet printer characterized by being used.