JP3179674B2 - Image recording method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording method and apparatus, and more particularly to an image recording method and apparatus capable of low-power and high-speed recording using a recording head having a plurality of recording elements.

[0002]

2. Description of the Related Art Conventionally, there are a thermal transfer system, an ink jet system and the like in serial printers. Each of these apparatuses has a plurality of printing element arrays, arranges the printing element arrays in parallel to the recording paper conveyance direction, and sequentially scans the recording element arrays perpendicularly to the paper conveyance direction to achieve one-by-one printing.
Achieve the recording of a sheet of recording paper.

In recent years, there has been a remarkable tendency to increase the number of recording elements included in the above-mentioned recording element array (lengthening of the recording head) in order to achieve a higher recording speed.

[0004]

However, problems associated with such an increase in the length of the power supply include problems such as an increase in the capacity of the power supply, an increase in the size of the power supply, and an increase in the cost.

As for power supplies, with the advancement of switching power supply technology, small, high-efficiency, high-power switching
Although adapters have become widespread, such adapters are more expensive than conventional transformer-type AC adapters.

[0006] The increase in power required for the power supply as described above is mainly due to the increase in power required for recording as the recording head becomes longer. That is, as the number of printing elements increases, the number of printing elements that must be driven within a unit time increases. For example, an image having an average Z [%] density can be ejected by an n-nozzle inkjet printing head. The power Pn when recording with f [Hz] and a drive pulse width T [sec] is as follows: Pn = (IVn) ・ (TF) Z (Equation 1) where I: each recording element The peak value V of the rectangular pulse current flowing through V is the power supply voltage value.

As can be understood from (Equation 1), the power P
It can be seen that n increases as the number of nozzles n increases, as the ejection frequency f increases, and as the average density Z further increases.

Therefore, it is necessary to reduce these parameters in order to increase the number of nozzles for high-speed printing and reduce the power. However, Z is a value specific to an image, and a decrease in f is not preferable because it causes a decrease in recording speed.

The present invention has been made in view of the above conventional example, and achieves a reduction in power of a power supply, an increase in recording speed, and high quality image recording when a recording head having a plurality of recording elements is used. It is an object to provide an image recording method and an apparatus thereof.

[0010]

In order to achieve the above-mentioned object, an image recording apparatus according to the present invention records an image by sequentially scanning a recording head having a plurality of recording elements in a direction different from a conveying direction of a recording medium. Detecting means for detecting a print duty of an area smaller than a print area to be printed by one scan in an image printing apparatus for performing image printing by selecting a print mode from a plurality of print modes. A threshold corresponding to the selected recording mode is selected from among a plurality of different thresholds corresponding to the recording modes of the above. When the detected recording duty is larger than the selected threshold, 1 Printing means for completing printing for one scan in a plurality of printing scans in order to reduce the load on the print head per unit time when printing by scanning. That.

Another recording apparatus according to the present invention performs image recording by sequentially scanning a recording head having a plurality of recording elements in a direction different from a conveying direction of a recording medium, and simultaneously records a plurality of different types of recording. In an image recording apparatus that performs image recording by selectively using a head, a detecting unit that detects a recording duty of an area smaller than a recording area that is recorded by one scan, and a different detector corresponding to the types of the plurality of recording heads A threshold is selected from a plurality of thresholds in accordance with the printhead to be selected and used, and when the detected print duty is greater than the selected threshold, printing is performed in one scan using the printhead. In order to reduce the load per unit time, a printing unit for completing printing for one scan by a plurality of printing scans is provided.

Further, according to the image recording method of the present invention, image recording is performed by sequentially scanning a recording head having a plurality of recording elements in a direction different from the conveying direction of a recording medium. In an image recording method for performing image recording by selecting a recording mode, a detecting step of detecting a recording duty of an area smaller than a recording area recorded by one scan, and a plurality of thresholds different from each other corresponding to the plurality of recording modes. From among them, a threshold according to the selected print mode is selected, and when the detected print duty is larger than the selected threshold, printing per unit time when printing in one scan in the print mode is performed. A printing step of completing printing for one scan by a plurality of printing scans in order to reduce the load on the head.

Further, another image recording method according to the present invention comprises:
An image recording method for performing image recording by sequentially scanning a recording head having a plurality of recording elements in a direction different from the transport direction of a recording medium and selectively performing image recording using a plurality of different types of recording heads A detecting step of detecting a print duty of an area smaller than a print area to be printed in one scan; and a plurality of thresholds corresponding to the types of the plurality of print heads, according to a print head selected and used. When the print duty is larger than the selected threshold value, one or more print scans are performed in a plurality of print scans in order to reduce the load per unit time for printing in one scan using the selected print head. A printing step for completing printing for the scanning.

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the main points of a recording apparatus according to an embodiment of the present invention will be summarized below. The printing apparatus of this embodiment has a plurality of print modes for printing a predetermined print area corresponding to the effective print width of the print head by a single scan or a plurality of scans. Is counted before recording, an effective pixel ratio with respect to the total number of pixels in the buffer is obtained, and recording is performed based on the effective pixel ratio (or a value or sign related thereto) and a recording mode such as a type of recording head and a recording resolution. To provide an image recording method and apparatus capable of determining the number of passes and driving with a small-capacity power supply.

Hereinafter, embodiments according to the present invention will be described in detail.

FIG. 1 is a diagram showing an outline of the present image recording apparatus. Here, reference numeral 1 denotes a CPU, which controls the entire image recording apparatus. Reference numeral 2 denotes a ROM which stores the image recording processing program of the present embodiment and the like, and is read and executed by the CPU 1. Programs corresponding to various processing flowcharts described later are stored in the ROM 2. Reference numeral 3 denotes a RAM which is used as a work area for executing the program or as a print buffer described later. Reference numeral 4 denotes an image input unit, which can input an image from an external computer or read the image by a built-in scanner (not shown). An image forming unit 5 inputs image data from a print buffer area of the RAM 2 and forms an image. Reference numeral 6 denotes an effective pixel number counting unit that counts the number of effective pixels described below from print data stored in the built-in DRAM 8. Reference numeral 20 denotes an operation panel for setting a recording mode and the like.

Next, FIG. 2 shows the configuration of the print buffer of the printing apparatus of the present embodiment. This print buffer is allocated to the DRAM 8, for example. It goes without saying that this print buffer may be allocated to the RAM 3. Reference numeral 7 denotes an internal bus, which includes an address bus, a data bus, and a control bus.

The recording apparatus of this embodiment uses, for example, a 360 dpi (dot per inch) 128 nozzle ink jet recording head shown in FIG. In this embodiment, the recording head is of a type that ejects ink droplets from nozzles by causing a state change in ink using thermal energy. However, due to the nature of conventional serial printers, text 1 is sent from the host computer.
In order to transfer data based on data for a row,
The configuration of the print buffer is 64 bytes as shown in FIG.
It is based on a band configuration with a dot width.

That is, as shown in FIG.
360dpi for 4E emulation mode
Resolution printer, the print buffer contains
Characters having a typical width of 36 dots and a height of 60 dots are stored in a maximum of 80 digits corresponding to A4 size recording paper. That is, the number of effective dots in the horizontal direction is 2880 dots (36 × 80) (see FIG. 2). When the contents of the print buffer are actually printed, as shown in the right figure of FIG. 4, the gray area of the print buffer (see the left figure of FIG. 2), that is, the recording is performed by packing 4 dots. It is necessary to. The conversion from the left diagram to the right diagram is achieved by dedicated hardware or software. However, since this is a technology not directly related to the present embodiment according to the present invention, a detailed description is omitted.

Returning to FIG. 2, each print buffer is 64
It has a dot width, and these 64 dots are divided in units of 8 dots. That is, 8 dots correspond to 1-byte data. The numbers in FIG. 2 indicate the lower 8 bits of the byte address, and the address advances toward the right of the buffer. 1
One print buffer is 23040 bytes (8 × 2
880 bytes). The same applies to the print buffer 2, the print buffer 3, and the print buffer 4.

In this embodiment, as shown in FIG. 2, four print buffers are used, the contents of the print buffer 1 and the print buffer 2 are simultaneously recorded, and
The contents of the buffer 3 and the print buffer 4 are simultaneously recorded. Since four buffers are provided, the contents to be recorded next are stored in the print buffers 3 and 4 while the contents of the print buffers 1 and 2 are being recorded. Similarly, while the contents of the print buffer 3 and the print buffer 4 are being recorded, the contents to be recorded next are stored in the print buffer 1 and the print buffer 2.

By the way, in the recording apparatus of this embodiment, FIG.
And a recording head having a power supply voltage of 24 V, a pulse current of 200 mA, and a frequency of 6.
Drive is performed at 25 KHz and a drive pulse width of 5 uS. At this time,
When solid black recording is performed, the power consumption of the head is approximately 23 W from (Equation 1). Assuming that the efficiency η of a DC-DC converter or a switching power supply for generating a more accurate head voltage is, for example, 80%, the power consumed when viewed from the input of the power supply is about 29 watts. .

Further, in the ink jet printer and the like used in the embodiment according to the present invention, in addition to the above, a power supply for logic (usually 5 V), a paper feed motor and a recording head
A power supply for the carriage driving motor (which may be shared with the head driving power supply) is required, and if these are included, the total power required for the power supply is 35 to 40 W. Providing such power with a dropper-type AC adapter constituted by an inexpensive transformer is impractical because the shape and weight of the AC adapter increase in size and weight.

Accordingly, in order to realize such a power supply, a switching type adapter is usually used. However, such an adapter achieves miniaturization but is expensive in terms of cost. Therefore, in the present embodiment, the recording mode is determined by counting the number of black dots, as described below, and operation is possible even with a low power supply.

Next, FIG. 5A shows the 128 nozzle of FIG.
It is a conceptual diagram of a Bk (black) cartridge having a configuration divided into three segments of 43-43-42 nozzles. Each of these segments can be independently activated. FIG. 5B shows the total number of nozzles 13
1 shows an example of a configuration of a color cartridge having six cartridges.
This color cartridge basically has two use modes.

First, when a color image other than black is generated, 24 nozzles of Y (yellow), 24 nozzles of M (magenta), and 2 nozzles of C (cyan) are arranged in order from the top in FIG. 5B.
Printing is performed in a color mode using a total of 96 nozzles of 4 nozzles and 24 Bk (black) nozzles. When printing black, 64 Bks are printed in order from the bottom in FIG. 5B.
(Black) Print in black mode using nozzles.

The details of the recording method for each cartridge described above will be described later. The Bk cartridge (FIG. 5A) has a total number of nozzles of 128, and the color cartridge (FIG. 5B) has a total number of 13 nozzles.
However, as described above, up to 96 (24 × 4) colors are used in color printing, and only 64 nozzles are used in black printing in a color cartridge.
Cartridges require more power. for that reason,
The BK cartridge performs printing in three passes, and the color cartridge performs printing in two passes.

In the case of printing in a high-quality (fine) mode to be described later, a plurality of passes (Bk 4 passes, color 3 passes, color B
Printing is performed with K only (2 passes). Next, referring to FIG.
The concept of a recording method on a recording medium will be described. FIG.
, An effective recording area having a width of 2880 dots is allocated in the horizontal axis direction of the recording medium. Then, this effective recording area is divided into 15 sections, and the section numbers of each effective recording area are 1 to 1
5 is assumed. One effective recording area is defined as 192 dots. In addition, four drawing areas 1 to 4 are shown in the vertical axis direction of the recording medium. Fig. 2
Correspond to the print buffers 1 to 4 shown in FIG.

In each section of the drawing areas 1 and 2, a plurality of types of recording are shown, and the "%" display shown therein indicates the effective pixel rate in that section, that is, the total number of dots included in each section described above. Is the ratio of the actually recorded dot number to For example, in the area of section number 2 in the drawing area 2, the entire area is shown as solid black recording, and the effective pixel rate is 100%. Further, for example, the area of section number 6 of the drawing areas 1 and 2 has an effective pixel rate of 5
Shown at 0% halftone. Furthermore, the area of the section number 13 of the drawing areas 1 and 2 indicates that the ratio of the solid black recording area is 35% or less of the area of one section. Hereinafter, the effective pixel rate may be simply referred to as a duty.

Note that 64 dots in the drawing area n (n = 1, 2,...) Length in the vertical axis direction of the recording medium in FIG. 6 show an example of recording, and this is black printing by a color cartridge. Is performed when black 64 is used. When color printing is performed using a color cartridge, 96 dots are formed corresponding to 96 nozzles (24 × 4). Further, when recording with a Bk cartridge, 1
128 dots correspond to 28 nozzles.

Here, as described with reference to FIG. 5A, the Bk cartridge is composed of three segments 43-43-42 and can be activated in segment units.
It goes without saying that the number of nozzles in each segment can be used. Similarly, as described with reference to FIG. 5B, when performing black recording with the color cartridge, the black nozzle 64 is used.
Is composed of two segments (having 32 nozzles each) and can be activated in segment units. It goes without saying that the drawing area length can be the number of nozzles in each of these segments.

FIG. 7 shows a detailed configuration of the effective pixel number counting section 6 for calculating the duty. FIG. 7 illustrates a portion related to the control of the CPU 1 and the effective pixel number counting section 6 extracted from FIG. 1 in order to facilitate the reader's understanding. Here, the effective pixel number counting unit 6 includes the DRAM 8 to which the above-described image buffer is allocated,
An internal unit including a DRAM controller 9 for controlling the input and output of data to and from the AM 8, a decoder 10 for decoding data read from the DRAM 8 and outputting the number of effective pixels, and an adder 11 for sequentially adding the number of effective pixels The bus 7 is an address bus 1 for the DRAM controller 9.
2, a data bus 13 for inputting / outputting data between the DRAM 8 and the CPU 1, and a read control line 14 for controlling reading of data from the DRAM 8 to the DRAM 9 and reading of addition result data from the adder 11.

When the DRAM controller receives a predetermined duty calculation instruction command from the CPU 1, the DRAM controller
The print data stored in the image buffer in the DRAM 8 is sequentially read and sent to the decoder 10. Reading is performed for each section of the effective recording area described with reference to FIG.
The duty value corresponding to the section is finally added to the adder 11.
Is obtained. The obtained duty value for each section is
The data is transferred to the CPU 1 via the data bus 13.

For example, at 360 DPI, the number of effective dots of each data of the block size is counted in units of 192 horizontal dots in blocks, and at 720 DPI, every 384 dots, the duty is calculated. Next, a print processing procedure according to the present embodiment will be described with reference to the flowchart in FIG. The program code corresponding to this flowchart is RO
It is stored in advance in M2, and is read, interpreted, and executed by CPU1.

In step S1, a recording mode, that is, a print mode (resolution: 720 dpi, 360 dpi; recording speed / recording quality: high quality, normal, or high speed) and the type of head (monochrome cartridge or color cartridge) mounted on the image forming unit are set. Then, in the case of a color cartridge, it is determined whether the mode is the color print mode or the monochrome print mode.

The print mode described above may be specified, for example, based on an input command from the operation panel 20, according to a mode specified in the ROM 2 in advance, or printed from the image data input unit 4. A print mode command may be input together with the image data to be printed. The type of the head is determined by inquiring of the image forming unit about the type of the head mounted on the image forming unit 5. When the image forming unit 5 includes a plurality of heads and is selectable, the operation panel 20 and the RO
The determination may be performed using M2 or each unit of the image data input unit 4.

The number of passes for image printing is determined based on the printing mode determined here and the duty described later. This number of passes will be described later with reference to FIG. Next, step S
In step 2, image data for one band is stored in the printer buffer of the DRAM 8. For example, if all image data is already R
If the data is stored in the AM 3, the data for one band to be printed therefrom is transferred to the printer buffer of the DRAM 8.

In step S3, one band of data stored in the printer buffer of the DRAM 8 is divided into areas having a predetermined number of recording dots. In step S4, the number of recording dots in one area divided in step S3, that is, the number of effective pixels is counted and set as a duty value. This process is executed by the effective pixel number counting unit 6 described with reference to FIG.

In step S5, a predetermined reference duty value (FIG. 9) based on the recording mode determined in step S1.
Compare the duty value counted in step S4 with the duty value counted in step S4. If the counted duty value is larger, the process proceeds to step S8, and the number of passes based on the determined recording mode (see the pass table in FIG. 9). Is performed, and the process is terminated. Conversely, if the counted duty value is not larger, the process proceeds to step S6.

In step S6, it is checked whether or not the counting of the duty values for the entire area of one band has been completed. If the counting has been completed, the process proceeds to step S7. Conversely, if the processing has not been completed, the process returns to step S4, and the same processing is performed for the next area in the same band. In step S7,
Normal recording is performed in accordance with the recording mode (determined by referring to the path table in FIG. 9), and the process ends.

As described above, by selecting an appropriate recording method based on the comparison between the reference duty range determined by the type of recording mode and the counted duty value, it is possible to use a large-capacity power supply. Thus, high-speed recording can be performed according to the recording data. next,
With reference to the pass table (FIG. 9), a method of selecting the number of printing passes based on the printing mode and the counted duty value will be described.

The path table shown in FIG. 9 is in a table format, and the vertical direction indicates the type of print mode, and 720 dpi.
Resolution mode and 360 dpi resolution mode
There is a mode. Furthermore, the 720 dpi resolution mode is divided into a high quality mode for forming a higher quality image and a normal mode for forming a normal quality image. Also,
The mode of the resolution of 360 dpi is divided into a high-quality mode for forming a higher-quality image, a normal mode for forming a normal-quality image, and a high-speed mode for forming a higher-speed image.

The horizontal direction indicates various types of cartridges (namely, types of heads), and there are two types of monochrome cartridges (namely, Bk cartridges) and color cartridges. Further, as described above, the color cartridge has two modes: a color print mode for printing a color other than black, and a monochrome print mode for printing black (that is, a black print mode).

In each element column of the table of FIG. 9 corresponding to the combination of the vertical and horizontal modes, a duty value range condition and the number of image forming passes corresponding to the duty value range condition are described. In steps 7 and S8 described above, the number of passes for image recording is determined by referring to this path table, and image recording processing is performed. After the basic concept of the image recording process is described with reference to FIGS. 10 and 11, the number of passes in each combination in FIG. 9 will be described.

FIG. 10 is a diagram for explaining the concept of a printing method in a plurality of passes when a monochrome head (Bk cartridge) is used. To make it easier for readers to understand,
The maximum capacity of the power supply for supplying power to the image recording apparatus of FIG.
The capacity is such that 48 nozzles can be driven. In this case, FIG.
If all the nozzles of the 0-128 monochrome head are activated at the same time, the drive cannot be performed due to insufficient power capacity. Therefore, the data is divided into the segment units (43 or 42 nozzles) described with reference to FIG.
That is, at the same time, since the driving of a maximum of 43 nozzles is sufficient, the driving can be performed by the power supply.

FIG. 11 is a diagram for explaining the concept of a printing method in a plurality of passes when a color head (color cartridge) is used. The color head has 96 actual driving nozzles at the time of color printing, and the power consumption of the head is about 20% less than that of the monochrome head.
Two-pass split recording is possible. That is, in the first pass, Y
(Yellow), M (magenta) and C on the second pass
(Cyan) and Bk (black) are recorded.

Next, returning to FIG. 9, the number of paths in each combination of the path tables will be described. (4,1). <360dpi-normal-monochrome cartridge>
In the case of, the number of nozzles of the monochrome cartridge is 128 and the maximum capacity of the power supply is 48 nozzles as described above. Therefore, the boundary of the reference duty of whether or not to perform divisional recording is 48/128 = 37. However, in order to execute printing with a duty of 100%, three divided printings, that is, image printing processing in three passes is required. Therefore, the boundary between the reference duties of whether or not to perform division recording is eventually 100/3 ≒ 34%. (4, 2). In the case of <360 dpi-normal-color cartridge-color print>: Since the number of nozzles of the color cartridge is 136 as described in FIG. Is 48/136 = 35%.

On the other hand, the actual driving among the 136 nozzles is as follows.
96 (Yx24, Mx24, Cx24, Bkx
24), so that 96/136 = 70%, and a duty of 100% is not generated at the maximum, so that 70/35 = 2, and printing processing can be performed in two passes. (4,3). <360dpi-normal-color cartridge-monochrome print>: Bk of color cartridge
The (black) nozzle consumes a little more energy than the color nozzle and has a power supply capacity of 42 nozzles. Therefore, the boundary of the reference duty of whether or not to perform divisional printing is 42/136 ≒ 31%.

Further, since the monochrome nozzles are 64 nozzles, the maximum is 64/136 と な り 47%, so that two-pass printing processing is sufficient. (5,1). <360 dpi-high-speed-monochrome cartridge>: In the high-speed recording mode, high-speed image recording is performed at a recording ink ejection frequency of 9.19 KHZ. On the other hand, in the normal mode, the ejection frequency of the recording ink is 6.25 KHZ.
To record an image.

When the threshold in the normal mode is converted by the ratio of these frequencies, the threshold in the recording mode of (4,1) is 37.5%, so that 37.5 (%) × 6.25 / 9. In the high-speed recording mode in which the threshold value is 19 = 25.5%, the recording data is decimated by half immediately before recording, so that the maximum is 50%,
Even when recording with a pass, the maximum is 50 (%) / 2 = 25%. Therefore, the boundary of the reference duty for determining whether or not to perform divisional printing is 25%. (5,2). In the case of <360 dpi-high-speed-color cartridge-color print>: The boundary of the reference duty of whether or not to record in division is calculated by converting the threshold value in the normal mode to 35 (%) × 6. 25 / 9.19 = 24%.

On the other hand, in relation to the number of actual driving nozzles, the duty is 70% at the maximum, and it is thinned out to less than half. Therefore, the duty is 35% at the maximum, so that 35 (%) / 24 (%) = 1.5. <2, and printing can be performed in two passes. (5,3). <360dpi-high-speed-color cartridge-monochrome print>: As in the case of (5,2), 31 (%) × 6.25 / 9.19 = 22% is divided and recorded. It is a boundary of the reference duty of whether or not. (2,1). <720dpi-normal-monochrome cartridge>
In the case of: Since it is necessary to form double-density dots as compared with the case where the resolution is 360 dpi, that is, the ejection energy 2
Since the threshold value is doubled, the threshold value is halved compared to the case of 360 dpi.

34 (%) / 2 = 17% is the boundary of the reference duty for determining whether or not to perform divisional recording. On the other hand, the data in the case of 720 dpi is thinned out by half, and the duty is 50% at the maximum, so that 50 (%) / 17% = 2.9 <3, and the recording process can be performed in three passes. (2,2). In the case of <720 dpi-normal-color cartridge-color print>: the ejection frequency in the case of (4,2) is 6.25 KHZ, whereas the ejection frequency in this mode is 4 .6KHZ.

When hitting at this frequency, the operation of "halving the threshold value" as in the case of a monochrome cartridge is unnecessary. This is because the discharge becomes slower and the discharge energy does not need to be changed. Therefore, the conversion is performed using the frequency ratio, and 35 (%) × 4.6 (k) /6.25 (k) = 26% is the boundary of the reference duty for determining whether or not to perform division recording.

On the other hand, the maximum duty is input at 50% as in the case of monochrome, so that printing processing can be performed in two passes. (2,3). In the case of <720 dpi-normal-color cartridge-monochrome print>: As in the case of the monochrome cartridge, the threshold value is set to half of 360 dpi, and 31 (%) / 2 = 15% is recorded by division. It is a boundary of the reference duty of whether or not. (1,1)-(1,3), (5,1)-(5,3). High quality mode:
Printing in the high-quality mode is to complete the printing of one band (width of the print head) in a plurality of scans using different areas of the print head in order to reduce a streak (banding) in a serial scan. This means a recording method for recording a high-quality image.

With reference to FIGS. 12A, 12B and 12C, the concept of the recording method in the high quality mode will be described. To facilitate the reader's understanding, the number of nozzles in the head is eight.
In the high-quality mode, as shown in FIGS. 12A, 12B, and 12C, printing is performed in a plurality of passes in a staggered manner. For example, 2
In the case of the pass, the paper feed amount is set to の of the width of the head, and the print data is thinned to で in one scan (in a zigzag and inverted zigzag pattern), and printing is completed in two scans.

FIGS. 12A, 12B, and 12C illustrate how printing in a fixed area is completed using the staggered and inverted staggered patterns, respectively, using a multi-head having eight nozzles. Things. First, in the first scan, a staggered pattern (hatched circles) is printed using the lower four nozzles (see FIG. 12A). Next, in the second scan, the paper is fed by 4 pixels (1/2 of the head length), and the inverted zigzag pattern (open circles) is recorded (FIG. 12).
B). Further, at the third scan, the paper is fed again by four pixels (１ of the head length) again, and the staggered pattern is recorded again (FIG. 12C).

In this manner, by sequentially performing paper feed in units of four pixels and recording in a staggered and inverted zigzag pattern, a recording area in units of four pixels is completed for each scan. As described above, by completing printing in the same area using two different types of nozzles, it is possible to obtain a high-quality image without density unevenness. In the monochrome cartridge, 128 nozzles are divided into four, so that in the color mode of the color cartridge, 32 nozzles are practically divided into 32 nozzles. Since it is divided into two, it is equivalent to 32 nozzles.

As described above, in each case, the driving is performed within 48 nozzles which is the upper limit of the power supply capacity.
There is no need to perform control based on the duty.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Needless to say, the present invention can be applied to a case where the present invention is achieved by supplying a program to a system or an apparatus.

As described above, according to the embodiment of the present invention, in a recording apparatus using a long recording head,
Before actually recording on recording paper, the effective pixel ratios of a plurality of print buffers corresponding to the drawing area to be recorded next are investigated, and based on the investigation results and the predetermined recording mode, the used portion of the recording nozzle is determined. By selecting and selecting the number of recording passes, it is possible to provide a recording method and apparatus capable of using a low-power and low-cost power supply. Thus, in practical use, an image with a low effective pixel rate such as a text that frequently occurs can be recorded at high speed using all the recording elements of the long recording head, and a graphic with a high effective pixel rate can be obtained. Alternatively, for an image or the like, it is possible to provide a printing method and apparatus for performing printing processing flexibly in response to print contrast characteristics, such as performing multiple scans.

Although the method of reducing the load on the recording head by using a plurality of passes has been described, it may be realized by lowering the drive frequency. Further, in the above-described embodiment, as a determination method for reducing the load on the printhead,
The recording duty is detected by dividing one line into a plurality of regions. However, it is needless to say that any method may be used as long as the recording duty of the local data is detected without being fixed to this method.

[0070]

As described above, according to the present invention, high-speed and high-quality images can be recorded in accordance with recording data and a predetermined recording mode without using a large-capacity power supply. .

[0071]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of an image recording apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a print buffer configuration of a recording apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a monochrome recording head used in the present embodiment.

FIG. 4 is a diagram showing how characters actually recorded are stored in the print buffer of FIG. 2;

FIG. 5A is a diagram showing a segment configuration of a Bk (black) cartridge.

FIG. 5B is a diagram showing a segment configuration of the color cartridge.

FIG. 6 is a diagram illustrating the concept of image recording on a recording medium.

FIG. 7 is a diagram showing a detailed structure of an effective pixel number counting unit.

FIG. 8 is a diagram illustrating a procedure of an image recording process in the image recording apparatus according to the present embodiment.

FIG. 9 is a diagram illustrating a path table for determining a method of image recording processing in the image recording apparatus according to the present embodiment.

FIG. 10 is a diagram for explaining a division recording method when a monochrome head is used.

FIG. 11 is a diagram for explaining a division recording method when a color head is used.

FIG. 12A is a diagram for explaining a recording method in a high quality mode.

FIG. 12B is a diagram for explaining a recording method in the case of a high-quality mode.

FIG. 12C is a diagram for explaining a recording method in the case of the high-quality mode.

[Explanation of symbols]

 Reference Signs List 1 CPU 2 ROM 3 RAM 4 Image data input unit 5 Image forming unit 6 Effective pixel count unit

Claims (44)

(57) [Claims] An image recording is performed by sequentially scanning a recording head having a plurality of recording elements in a direction different from a conveying direction of a recording medium , and recording is performed from among a plurality of recording modes.
An image recording apparatus for performing image recording by selecting a recording mode , comprising: detecting means for detecting a recording duty of an area smaller than a recording area recorded in one scan; and a plurality of thresholds corresponding to the plurality of recording modes. During ~
A threshold corresponding to the selected printing mode is selected, and when the detected printing duty is larger than the selected threshold , printing is performed in one scan by the printing mode.
Reduced <br/> load of the recording head per unit time Ji when Rubeku, an image recording apparatus comprising: a recording means for completing recording of one scanning in the plurality of print scans. 2. The method according to claim 1, wherein the plurality of threshold values are one for each recording mode.
2. The image recording apparatus according to claim 1, wherein the threshold value reflects a difference in load of a recording head per unit time when recording by scanning. 3. The image recording apparatus according to claim 1, wherein the recording mode includes a resolution mode . 4. The image recording apparatus according to claim 2, wherein the resolution mode includes a low resolution mode and a high resolution mode . 5. The image recording apparatus according to claim 1, wherein the recording mode includes a high-quality mode for forming a high-quality image. 6. The image recording apparatus according to claim 1, wherein the recording mode includes a high-speed mode for forming an image at high speed. 7. The image recording apparatus according to claim 1, wherein the recording mode includes a normal mode for forming a normal quality image. 8. Image recording is performed by sequentially scanning a recording head having a plurality of recording elements in a direction different from the transport direction of the recording medium, and image recording is performed by selectively using a plurality of different types of recording heads. And a detecting means for detecting a print duty of an area smaller than a print area printed by one scan, and a plurality of different thresholds corresponding to the types of the plurality of print heads. A threshold corresponding to the printhead to be selected, and when the detected print duty is greater than the selected threshold, one is determined using the printhead.
An image recording apparatus comprising: recording means for completing recording for one scan by a plurality of recording scans in order to reduce a load per unit time for recording by scanning. 9. The printing apparatus according to claim 8, wherein the plurality of thresholds are thresholds reflecting a difference in load on a print head per unit time when printing in one scan for each type of print head. Image recording device. 10. The print duty is a ratio of the number of print data actually printed to the number of print data in an area smaller than a print area printed in one scan. 9. The image recording device according to 1 or 8 . Wherein said recording duty, the of the recording data in smaller areas than the recording area recorded by one scan, claim 1 or 8, characterized in that the number of recording data to be actually recorded The image recording apparatus according to claim 1. 12. The detection means decodes print data in an area smaller than the print area printed in one scan, and outputs the number of print data actually recorded included in the print data. the image recording apparatus according to claim 1 or 8, characterized in that it comprises a decoding means. 13. The recording device according to claim 1, wherein the detecting unit decodes print data in an area smaller than an area smaller than the print area recorded in the one scan, and records the actually recorded data included in the print data in the smaller area. First decoding means for outputting the number of pieces of print data to be printed, and the number of pieces of print data actually printed included in the print data of the smaller area output from the first decode means, which is calculated by one scan. in an image recording apparatus according to an adding means for adding throughout a region smaller than the recorded the recording area to claim 1 or 8, characterized in. 14. The image recording apparatus according to claim 8 , wherein the types of the recording head include a monochrome head for recording black and a color head for recording color. 15. The image recording apparatus according to claim 14 , wherein the color head includes a head for outputting each color of yellow, cyan, magenta, and black for recording a color. 16. A color mode for outputting a synthesized color using a head for outputting each color of yellow, cyan, magenta, and black for recording a color, and a black head among the color heads. The image recording apparatus according to claim 15 , further comprising a black mode for outputting black by using a black mode. 17. The recording unit, image recording apparatus according to claim 1 or 8, characterized in that to reduce the number of used recording element per unit of the recording head time. 18. The method according to claim 18, wherein the recording means selects the detection result and
A predetermined area of the printhead is selected based on the comparison with the threshold value, and printing for one scan is completed by the plurality of print scans .
9. The image recording apparatus according to claim 1, wherein: 19. The image recording apparatus according to claim 18 , wherein the recording head has a plurality of heads that can record another pixel at the same time. 20. The image recording apparatus according to claim 19 , wherein said plurality of heads record black pixels. 21. The image recording apparatus according to claim 19 , wherein the plurality of heads include a head for outputting each color of yellow, cyan magenta, and black for recording a color. 22. The image recording apparatus according to claim 18 , wherein the predetermined area of the recording head is an area in a plurality of predetermined segments constituting the recording head. 23. Image recording is performed by sequentially scanning a recording head having a plurality of recording elements in a direction different from the conveying direction of a recording medium , and a plurality of recording modes are selected.
An image recording method for performing image recording by selecting a recording mode , comprising: a detecting step of detecting a recording duty of an area smaller than a recording area recorded by one scan; and a plurality of thresholds different from each other corresponding to the plurality of recording modes. During ~
A threshold corresponding to the selected printing mode is selected, and when the detected printing duty is larger than the selected threshold , printing is performed in one scan by the printing mode.
Image recording method characterized in that it comprises load reduction <br/> the Ji Rubeku unit of recording head in per time for and a recording step of completing recording of one scanning in the plurality of print scans. 24. The image according to claim 23, wherein the plurality of thresholds are thresholds reflecting a difference in load on a print head per unit time when printing in one scan for each print mode. Recording method. 25. The recording mode is a resolution of image recording.
24. The image recording method according to claim 23 , comprising the following modes . 26. The image recording method according to claim 25 , wherein the resolution mode includes a low resolution mode and a high resolution mode. 27. The recording mode, according to claim 2, characterized in that it comprises a high-quality mode for forming an image of high quality
3. The image recording method according to 3 . 28. The recording apparatus according to claim 23 , wherein the recording mode includes a high-speed mode for forming an image at high speed.
The image recording method described in 1. 29. The image recording method according to claim 23 , wherein the recording mode includes a normal mode for forming a normal quality image. 30. Image recording is performed by sequentially scanning a recording head having a plurality of recording elements in a direction different from the transport direction of a recording medium, and image recording is performed by selectively using a plurality of different types of recording heads. A detection step of detecting a print duty of an area smaller than a print area printed in one scan; and a plurality of different threshold values corresponding to the types of the plurality of print heads. A threshold corresponding to the recording head to be selected, and when the recording duty is greater than the selected threshold, one is determined by using the selected recording head.
A printing step of completing printing for one scan by a plurality of printing scans in order to reduce a load per unit time for printing by scanning. 31. The apparatus according to claim 30, wherein the plurality of thresholds are thresholds reflecting a difference in load of a print head per unit time when printing is performed in one scan for each type of print head. Image recording method. 32. The print duty is a ratio of the number of print data actually printed to the number of print data in an area smaller than the print area printed by the one scan. 30. The image recording method according to 23 or 30 . 33. The print duty according to claim 23 , wherein the print duty is the number of print data actually printed out of print data in an area smaller than the print area printed in one scan. The image recording method described in 1. 34. The detecting step decodes print data in an area smaller than the print area printed in the one scan, and outputs the number of print data actually recorded included in the print data. 31. The image recording method according to claim 23, further comprising a decoding step. 35. The detecting step, wherein the recording data in an area smaller than the area smaller than the recording area recorded in the one scan is decoded, and the actual recording included in the recording data in the smaller area is performed. A first decoding step of outputting the number of pieces of print data to be printed, and the number of pieces of print data actually printed included in the print data of the smaller area output from the first decode step, which is calculated by one scan. 31. The image recording method according to claim 23, further comprising: an adding step of adding over an entire area smaller than the recording area recorded in the step (c). 36. The image recording method according to claim 30 , wherein the types of the recording head include a monochrome head for recording black and a color head for recording color. 37. The image recording method according to claim 36 , wherein the color head includes a head for outputting each color of yellow, cyan, magenta, and black for recording a color. 38. A color mode for outputting a composite color using a head for outputting each color of yellow, cyan, magenta, and black for recording a color, and using a black head among the color heads. 38. The image recording method according to claim 37 , further comprising a black mode for outputting black by using a black mode. 39. The image recording method according to claim 23 , wherein in the recording step, the number of recording elements used per unit time of the recording head is reduced. 40. The printing step, wherein a predetermined area of the printing head is selected based on a comparison between the detection result and the selected threshold, and printing for one scan is performed by the plurality of printing scans. 31. The image recording method according to claim 23, wherein the image recording method is means for completing the image recording. 41. The image recording method according to claim 40 , wherein the recording head has a plurality of heads capable of recording another pixel at the same time. 42. The image recording method according to claim 41 , wherein said plurality of heads record black pixels. 43. The image recording method according to claim 41 , wherein the plurality of heads include a head for outputting each color of yellow, cyan magenta, and black for recording a color. 44. The image recording method according to claim 40 , wherein the predetermined area of the recording head is an area in a unit of a plurality of predetermined segments constituting the recording head.