JPH08290562A - Method for image recording and device therefor - Google Patents

Abstract

PURPOSE: To provide an image recording device which uses a low power supply, records data at high speed and realizes a high-quality recorded image in an image recording device provided with a plurality of recording elements. CONSTITUTION: This image recording device records an image by sequentially scanning with a recording head provided with a plurality of recording elements in a different direction from a recording sheet transport direction. The device comprises detection means 1, 8 which detect a printing duty for a smaller recording region than a recording region recorded in a single scan, and recording means 1, 2, 3 which reduce the number of recording heads, per unit time, used for recording data in a single scan under specified recording conditions, if the detected printing duty is higher than a specific threshold value corresponding to the specified recording conditions, and complete a recording of one single scan by recording scans.

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 an apparatus therefor, and more particularly to an image recording method and an apparatus therefor 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 inkjet system, etc. in a serial printer. Each of these devices has a plurality of recording element arrays, the recording element arrays are arranged in parallel in the recording paper conveyance direction, and the recording element arrays are sequentially scanned vertically in the paper conveyance direction, thereby
Achieve recording on a piece of recording paper.

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

[0004]

However, problems associated with such lengthening 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 cost.

With regard to power supplies, due to advances in switching power supply technology, small-sized, high-efficiency, high-power switching
Although adapters have become popular, such adapters are more expensive than conventional transformer-type AC adapters.

The increase in the power required for the power supply as described above is mainly due to the increase in the power required for recording accompanying the lengthening of the recording head. That is, as the number of recording elements increases, the number of recording elements that must be driven within a unit time also increases. For example, an image with an average Z [%] density is ejected by an inkjet recording head with n nozzles at an ejection frequency. The power Pn when recording at f [Hz] and drive pulse width T [sec] is: Pn = (I · V · n) · (T · f) · Z (Equation 1) where I: recording element The peak value of the rectangular pulse current flowing in the V is the power supply voltage value.

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

Therefore, it is necessary to reduce these parameters in order to achieve a high number of nozzles for high speed recording and reduce the power. However, Z is a value peculiar to the image, and a decrease in f causes a decrease in recording speed, which is not preferable.

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

[0010]

In order to achieve the above object, the image recording method and apparatus of the present invention include a detecting means for detecting a print duty of an area smaller than a print area printed by one scan, and The detected recording duty is
When it is larger than a predetermined threshold value corresponding to a predetermined print condition, the load per unit time of the print head used for printing in one scan under the predetermined print condition is reduced, and one scan is performed for a plurality of print scans. And recording means for completing the recording.

Another aspect of the present invention is to detect the print duty of a divided area obtained by dividing the print area to be printed by one scan into a plurality of areas, and the predetermined duty corresponding to the print duty of the divided area and a predetermined printing condition. A predetermined area of the print head based on a comparison result of the comparison means, a comparison result of the comparison means and the predetermined printing condition, and printing for one scanning is performed by a plurality of printing scans. And recording means for completing.

Another aspect of the present invention is a detection means for detecting a print duty of a divided area obtained by dividing a print area to be printed by one scan with a print width based on the type of print head and a print mode, and printing of the divided area. A recording unit that determines a use area of the recording head based on the duty, the type of the recording head, and the recording mode, and performs recording for one scan by a plurality of scans.

Another aspect of the present invention is a detection step of detecting a print duty of an area smaller than a print area printed by one scan, and the detected print duty is higher than a predetermined threshold value corresponding to a predetermined print condition. If it is also large, a printing step of reducing the load per unit time of the print head used for printing in one scan under the predetermined printing conditions to complete printing for one scan by a plurality of printing scans.

Further, according to another invention, a detection step of detecting a print duty of a divided area obtained by dividing a print area to be printed by one scan, and a predetermined duty corresponding to the print duty of the divided area and a predetermined print condition. Based on the comparison step of comparing with the threshold value, the comparison result in the comparison step, and the predetermined printing condition, a predetermined area of the print head is selected, and printing for one scan is performed by a plurality of print scans. And a recording step to complete.

Another aspect of the present invention is a detection step of detecting a print duty of a divided area obtained by dividing a print area to be printed in one scan with a print width based on the type of print head and a print mode, and printing of the divided area. A printing step of determining a use area of the print head based on a duty, a type of the print head, and the print mode, and performing printing for one scan by a plurality of scans.

[0016]

In the above structure, the detecting means detects the print duty of the area smaller than the print area printed by one scan, and the print means detects the print duty corresponding to the predetermined print condition. When it is larger than a predetermined threshold value, the load per unit time of the print head used for printing in one scan under the above-mentioned predetermined printing conditions is reduced, and printing for one scanning is completed by a plurality of printing scans.

According to another aspect of the invention, the detection means detects the print duty of a divided area obtained by dividing the print area printed by one scan into a plurality of areas, and the comparison means detects the print duty of the divided area and a predetermined print. Based on the comparison result of the comparison means and the predetermined printing condition, the printing unit selects a predetermined area of the print head by comparing with a predetermined threshold value corresponding to the condition, and performs a plurality of printing scans. Complete printing for one scan.

According to another aspect of the invention, the detecting means detects the print duty of a divided area obtained by dividing the print area to be printed by one scan with the print width based on the type of print head and the print mode, and the print means Recording duty of the divided area,
The use area of the print head is determined based on the type of the print head and the print mode, and printing for one scan is performed by a plurality of scans.

Another aspect of the present invention detects a print duty of an area smaller than a print area printed by one scan, and the detected print duty is larger than a predetermined threshold value corresponding to a predetermined print condition. The load per unit time of the print head used for printing in one scan under the predetermined printing conditions is reduced, and printing for one scan is completed by a plurality of printing scans.

Another aspect of the present invention detects the print duty of a divided area obtained by dividing a print area printed by one scan into a plurality of areas, and sets the print duty of the divided area and a predetermined threshold value corresponding to a predetermined print condition. The predetermined area of the print head is selected based on the comparison result in the comparison step and the predetermined print condition, and 1 is selected by a plurality of print scans.
Complete scan recording.

Another aspect of the invention is to detect a print duty of a divided area obtained by dividing a print area to be printed by one scan with a print width based on the type of print head and a print mode, and the print duty of the divided area, The type of the recording head,
The use area of the print head is determined based on the print mode, and printing for one scan is performed by a plurality of scans.

[0022]

First, the main points of a recording apparatus according to an embodiment of the present invention will be summarized below. The printing apparatus of the present 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 to obtain the effective pixel ratio to the total number of pixels in the buffer, and recording is performed based on the effective pixel ratio (or related value or code) and the recording mode such as the type of recording head and recording resolution. The present invention provides an image recording method and an apparatus therefor, which can determine the number of passes of the above, and can be driven by 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 image recording apparatus. Here, 1 is a CPU, which controls the entire image recording apparatus. Reference numeral 2 denotes a ROM, which stores the image recording processing program of this embodiment and the like, and is read and executed by the CPU 1. Programs corresponding to various processing flow charts described later are stored in the ROM 2. A RAM 3 is used as a work area for executing the program and as a print buffer described later. An image input unit 4 can input an image from an external computer or read it by a built-in scanner (not shown). An image forming unit 5 inputs image data from the print buffer area of the RAM 2 to form an image. An effective pixel number counting unit 6 counts the number of effective pixels, which will be described later, from the print data stored in the built-in DRAM 8. Reference numeral 20 is an operation panel for setting a recording mode and the like.

Next, FIG. 2 shows the structure of the print buffer of the recording apparatus of this embodiment. This print buffer is assigned to the DRAM 8, for example. It goes without saying that this print buffer may be assigned to the RAM 3. An internal bus 7 includes an address bus, a data bus, and a control bus.

The recording apparatus of this embodiment uses, for example, an inkjet recording head having 128 nozzles of 360 dpi (dot per inch) 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 the ink using thermal energy. However, due to the nature of conventional serial printers, the text 1 from the host computer
Since the data is transferred based on the data of the line,
The structure of the print buffer is 64 as shown in FIG.
It is based on a band structure with a dot width.

That is, as shown in FIG. 4, for example, X2
In case of 4E emulation mode, 360dpi
Resolution printers have
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 actually printing the contents of this print buffer, as shown in the right figure of FIG. 4, the area of the print buffer shown in gray (see the left figure of FIG. 2), that is, 4 dots is filled and recorded. It is necessary to. The conversion from the left diagram to the right diagram is achieved by dedicated hardware or software, but since this is a technology that is not directly related to this embodiment of the present invention, detailed description thereof will be omitted.

Returning to FIG. 2, each print buffer has 64
It has a width of dots, and these 64 dots are divided in units of 8 dots. That is, 8 dots correspond to 1 byte of 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 x 2
880 bytes). The same applies to the print buffer 2, print buffer 3, and print buffer 4.

In this embodiment, as shown in FIG. 2, four print buffers are used, the contents of print buffer 1 and print buffer 2 are recorded at the same time, and print
The contents of buffer 3 and print buffer 4 are recorded simultaneously. Since there are four buffers, the contents to be recorded next are stored in the print buffer 3 and the print buffer 4 while the contents of the print buffer 1 and the print buffer 2 are being recorded. Similarly, while recording the contents of the print buffer 3 and the print buffer 4, 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, as shown in FIG.
The 128-nozzle recording head shown in FIG. 2 was used, and this head had a power supply voltage of 24 V, a pulse current of 200 mA, and a frequency of 6.
It is driven at 25 KHz and a drive pulse width of 5 uS. This time,
When solid black recording is performed, the power consumption of the head is approximately 23 W according to (Equation 1). Assuming that the efficiency η of the DC-DC converter or the switching power supply for generating the head voltage with higher accuracy is 80%, for example, the power consumed when actually seen from the input of the power supply is about 29 watts. .

Further, in the ink jet printer used in the embodiment of the present invention, in addition to this, a logic power source (usually 5 V), a paper feed motor and a recording head
A power source for the motor for driving the carriage (may be shared with the power source for driving the head) is required, and if these are included, the total power required for the power source becomes 35 to 40 W. Providing such electric power through a dropper-type AC adapter configured by an inexpensive transformer is not practical because the shape and weight of the AC adapter increase in size and weight.

Therefore, in order to realize such a power supply, a switching type adapter is usually used, but such an adapter is small in size but expensive in 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 source.

Next, FIG. 5A shows the 128 nozzles of FIG.
It is a conceptual diagram of the Bk (black) cartridge which has the structure divided into three segments of 43-43-42 nozzles. Each of these segment units can be independently activated. FIG. 5B shows a total nozzle number of 13
An example of the configuration of a color cartridge having six pieces is shown.
This color cartridge basically has two usage 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 sequentially arranged from the top of FIG. 5B.
Printing is performed in a color mode using a total of 96 nozzles including 4 nozzles and 24 nozzles of Bk (black). Further, when printing a black color, 64 Bk in order from the bottom of FIG. 5B.
(Black) Print in black mode using nozzles.

The details of the recording method for each of the above-mentioned cartridges will be described later, but the Bk cartridge (FIG. 5A) has a total of 128 nozzles, and the color cartridge (FIG. 5B) has 13 nozzles.
However, as described above, the maximum is 96 (24 × 4) in color printing, and only 64 nozzles are used in black only printing in the color cartridge.
Cartridges require more power. for that reason,
The BK cartridge prints in 3 passes, and the color cartridge prints in 2 passes.

In the case of printing in a high-quality (fine) mode, which will be described later, in order to form an image of high quality n, a plurality of passes (Bk4 pass, color 3 pass, color B
Only K is printed in 2 passes. Next, referring to FIG.
The concept of the recording method on the recording medium will be described. Figure 6
With reference to, an effective recording area of 2880 dot width is allocated in the horizontal axis direction of the recording medium. Then, this effective recording area is divided into 15, and the partition number of each effective recording area is 1 to 1.
Set to 5. Further, one effective recording area is defined as 192 dots. Further, four drawing areas 1 to 4 are shown in the vertical axis direction of the recording medium. In each drawing area,
The print buffers 1 to 4 shown in FIG.

A plurality of types of recording are shown in each section of the drawing areas 1 and 2, and the "%" shown therein indicates the effective pixel ratio in that section, that is, the total number of dots included in each section described above. Is the ratio of the number of dots actually printed. For example, in the area of the partition number 2 of the drawing area 2, the entire area is shown as solid black recording, and the effective pixel rate is 100%. In addition, for example, the effective pixel ratio of 5 is applied to the areas of the partition numbers 6 of the drawing areas 1 and 2.
Shown with 0% halftone. Furthermore, it is shown that the ratio of the solid black recording area is 35% or less of the area of one partition in the area of partition number 13 of the drawing areas 1 and 2. Hereinafter, the effective pixel rate may be simply referred to as duty.

The 64 dots of the drawing area n (n = 1, 2, ...) In the vertical direction of the recording medium of FIG. 6 represent an example of recording, which is black printing with a color cartridge. It corresponds to using black 64 when performing. When performing color printing with a color cartridge, the number of dots is 96 corresponding to 96 nozzles (24 × 4). When recording with a Bk cartridge, 1
There are 128 dots corresponding to 28 nozzles.

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

FIG. 7 shows a detailed structure of the effective pixel number counting section 6 for calculating the above-mentioned duty. FIG. 7 illustrates a portion related to the control of the CPU 1 and the effective pixel number counting unit 6 extracted from FIG. 1 in order to facilitate the reader's understanding. Here, the effective pixel number counting unit 6 includes a DRAM 8 to which the above-mentioned image buffer is allocated and a DR.
An internal circuit including a DRAM controller 9 for controlling the input / output of data to / from the AM 8, a decoder 10 for decoding the 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 the 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 the reading of data from the DRAM 8 to the DRAM 9 and the 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 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 partition unit of the effective recording area described in FIG.
The duty value corresponding to the section finally becomes the adder 11
Can be obtained. The obtained duty value for each section is
It is transferred to the CPU 1 via the data bus 13.

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

In step S1, the recording mode, that is, the print mode (resolution: 720 dpi 360 dpi; recording speed / recording quality: high quality, normal or high speed) and the type of head mounted in the image forming section (monochrome cartridge or color cartridge) Further, in the case of a color cartridge, it determines the color print mode or the monochrome print mode.

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

The number of image recording passes is determined by the recording mode determined here and the duty described later. The number of passes will be described later with reference to FIG. Next, step S
In 2, the 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 it is stored in AM3, the data for one band to be printed is transferred to the printer buffer of DRAM8.

In step S3, the data for one band 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 print dots in one area divided in step S3, that is, the number of effective pixels is counted and set as a duty value. This processing is executed by the effective pixel number counting unit 6 described in FIG.

In step S5, a predetermined reference duty value (see FIG. 9) based on the recording mode determined in step S1.
(See) and the duty value counted in step S4, and if the counted duty value is larger, the process proceeds to step S8, and the number of passes based on the determined print mode (see the pass table in FIG. 9). Then, the divided recording is performed, and the process ends. On the contrary, 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 value for the entire area for one band is completed, and if it is completed, the process proceeds to step S7. On the contrary, if it 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,
According to the recording mode (determined by referring to the path table in FIG. 9), normal recording is performed, 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 source. It becomes possible to perform high-speed recording according to the recording data. next,
A method for selecting the number of passes for printing based on the printing mode and the counted duty value will be described with reference to the pass table (FIG. 9).

The path table of FIG. 9 is in a tabular form, and the vertical direction indicates the type of print mode, 720 dpi.
Resolution mode and 360 dpi resolution mode 2
There are modes. Further, 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 360 dpi resolution mode 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 an image at a higher speed.

The horizontal direction shows various types of cartridges (that is, types of heads), and there are two types, that is, monochrome cartridges (that is, Bk cartridges) and color cartridges. Furthermore, 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 these vertical and horizontal modes, the number of passes for image formation corresponding to the duty value range condition is described. In step 7 and step S8 described above, the number of image recording passes is determined by referring to this path table, and image recording processing is performed. The basic concept of this image recording process will be described with reference to FIGS. 10 and 11, and then the number of passes in each combination of 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 that supplies power to the image recording apparatus of FIG.
The capacity is such that 48 nozzles can be driven. In this case,
When all the nozzles of the monochrome nozzle of 128 nozzles of 0 are activated at the same time, the power source capacity is insufficient and the driving is impossible. Therefore, recording is performed by dividing the segment unit (43 or 42 nozzles) described in FIG. 5A into three passes.
That is, at the same time, it is possible to drive a maximum of 43 nozzles, and therefore it is possible to drive with the power source.

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 recording, and the head power consumption is about 20% less than that of the monochrome head.
Two-pass divided recording is possible. That is, Y in the first pass
(Yellow) and M (Magenta) are recorded, and C is used in the second pass.
(Cyan) and Bk (black) are recorded.

Next, returning to FIG. 9, the number of paths in each combination of path tables will be described. (4,1). <360dpi-normal-monochrome cartridge>
Case: The number of nozzles of the monochrome cartridge is 128, and the maximum capacity of the power source is 48 nozzles as described above. Therefore, the boundary of the reference duty of whether or not to perform divided recording is 48/128 = 37. Although it is 5%, three times of divided recording, that is, image recording processing in three passes is required to execute recording with a duty of 100%. Therefore, the boundary of the reference duty of whether or not the recording is divided is 100 / 3≅34%. (4, 2). <360 dpi-normal-color cartridge-color print>: Since the number of nozzles in the color cartridge is 136 as described with reference to FIG. The boundary of is 48/136 = 35%.

On the other hand, the actual driving in the 136 nozzles is
96 (Yx24, Mx24, Cx24, Bkx
24), 96/136 = 70%, and a maximum duty of 100% does not occur, so 70/35 = 2 and print processing can be performed in two passes. (4,3). <360dpi-normal-color cartridge-monochrome print>: Bk of color cartridge
The (black) nozzle consumes slightly 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 divided recording is 42 / 136≈31%.

Further, since the number of monochrome nozzles is 64, the maximum is 64 / 136≅47%, and a 2-pass printing process is sufficient. (5, 1). <360 dpi-high speed-monochrome cartridge>: In the high speed recording mode, the recording ink ejection frequency is 9.19 KHZ for high speed image recording. On the other hand, in the normal mode, the recording ink ejection frequency is 6.25 KHZ.
To record the 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 37.5 (%) × 6.25 / 9. In the high-speed recording mode where the threshold is 19 = 25.5%, the recording data is thinned in half immediately before recording, so the maximum is 50%, and 2
Even when recording with a pass, the maximum is 50 (%) / 2 = 25%. Therefore, the boundary of the reference duty for whether or not the recording is divided is 25%. (5, 2). <360dpi-high speed-color cartridge-color print>: The boundary of the reference duty of whether or not to record in division is 35 (%) x 6. 25 / 9.19 = 24%.

On the other hand, due to the number of actual driving nozzles, the maximum duty is 70%, and since it is decimated to less than half, the maximum duty is 35%, so 35 (%) / 24 (%) = 1.5. It becomes <2, and the recording process can be performed in two passes. (5,3). <360dpi-high speed-color cartridge-monochrome print>: As in the case of (5,2), 31 (%) x 6.25 / 9.19 = 22% is recorded in divided areas. It becomes the boundary of the reference duty. (2,1). <720dpi-normal-monochrome cartridge>
Case: As compared with the case where the resolution is 360 dpi, it is necessary to print double density dots, that is, the ejection energy is 2
Since it is doubled, the threshold is half that in the case of 360 dpi.

34 (%) / 2 = 17% is the boundary of the reference duty of whether or not recording is performed in division. On the other hand, the data in the case of 720 dpi is decimated to half, and the maximum duty is 50%, so that 50 (%) / 17% = 2.9 <3, and the printing process can be performed in three passes. (2,2). <720dpi-Normal-Color Cartridge-Color Print>: The ejection frequency in the case of (4,2) is 6.25KHZ, whereas the ejection frequency in this mode is 4 It will be .6KHZ.

When hitting at this frequency, the operation of "halving the threshold value" unlike the case of the monochrome cartridge is unnecessary. This is because the discharge becomes slow and the discharge energy does not change. Therefore, the conversion with the frequency ratio is performed, and 35 (%) × 4.6 (k) /6.25 (k) = 26% becomes the boundary of the reference duty of whether or not the recording is performed by division.

On the other hand, the maximum duty is input at 50% as in the case of monochrome, so that the recording process can be performed in two passes. (2,3). <720dpi-Normal-Color Cartridge-Monochrome Print>: Just like the case of the monochrome cartridge, the threshold is half of 360dpi and 31 (%) / 2 = 15% is divided and recorded. It becomes the boundary of the reference duty. (1,1)-(1,3), (5,1)-(5,3). High quality mode:
The printing in the high-quality mode is to complete the printing of one band (width of the printhead) complementarily by a plurality of scans using different areas of the printhead in order to reduce the connecting stripes (banding) of the serial scan. This means a recording method for recording a high quality image.

The concept of the recording method in the high quality mode will be described with reference to FIGS. 12A, 12B and 12C. To facilitate the reader's understanding, the number of head nozzles is eight.
In the high quality mode, as shown in FIGS. 12A, 12B, and 12C, printing is performed in a zigzag manner with a plurality of passes. For example, 2
In the case of a pass, the paper feed amount is set to ½ of the head width, and the print data is thinned to ½ in one scan (a staggered pattern and an inverted zigzag pattern), and printing is completed by two scans.

FIGS. 12A, 12B, and 12C illustrate how the recording of a certain area is completed when the zigzag and inverse zigzag patterns are used, using a multi-head having 8 nozzles. It is a thing. First, in the first scan, the staggered pattern (marked with diagonal lines) is recorded 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 reverse zigzag pattern (white circle mark) is recorded (FIG. 12).
B). Further, in the third scan, the paper is fed by 4 pixels (1/2 of the head length) again, and the staggered pattern is recorded again (FIG. 12C).

In this manner, the paper feed in units of 4 pixels and the recording of the staggered and reverse zigzag patterns are alternately performed in order to complete the recording area in units of 4 pixels for each scan. As described above, by completing recording with two different types of nozzles in the same area, it is possible to obtain a high-quality image without density unevenness. In the monochrome cartridge, 128 nozzles are divided into four, so that 32 nozzles are substantially divided. In the color mode of the color cartridge, 24 nozzles for each of the four colors are divided into three, so 32 nozzles, and in the monochrome mode 64 black nozzles are divided. Since it is divided into two, 32 nozzles are needed.

As described above, in any case, since the nozzles are driven within 48 nozzles, which is the upper limit of the power supply capacity,
It is not necessary to 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. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

As described above, according to the embodiment of the present invention, in the recording apparatus using the long recording head,
Before actually recording on the recording paper, the effective pixel ratios of the multiple print buffers corresponding to the drawing area to be recorded next are investigated, and based on the investigation result 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 that can use a low-power and low-cost power supply. As a result, in actual use, an image with a low effective pixel rate such as a text that is frequently generated can be recorded at high speed by using all 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 that flexibly respond to the characteristics of print contrast, such as performing multiple scans.

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

[0070]

As described above, according to the present invention, it is possible to record a high-quality image at high speed according to the recording data and a predetermined recording mode without using a large capacity power source. .

[0071]

[Brief description of drawings]

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

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

FIG. 3 is a diagram showing an example of a monochrome recording head used in this embodiment.

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

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

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

FIG. 6 is a diagram illustrating a 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 image recording processing in the image recording apparatus of the present embodiment.

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

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

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

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

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

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

[Explanation of symbols]

 1 CPU 2 ROM 3 RAM 4 Image data input unit 5 Image forming unit 6 Effective pixel number counting unit

Claims (50)

[Claims] 1. An image recording apparatus for recording an image by sequentially scanning a recording head having a plurality of recording elements in a direction different from a conveyance direction of a recording sheet, in an area smaller than a recording area recorded by one scan. A detecting unit for detecting a print duty; and a print head used for printing in one scan under the predetermined print condition when the detected print duty is larger than a predetermined threshold value corresponding to the predetermined print condition. An image recording apparatus comprising: a recording unit that reduces a load per unit time and completes recording for one scan by a plurality of recording scans. 2. 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. 1. The image recording device described in 1. 3. The print duty of the print data in an area smaller than a print area printed in one scan,
The image recording apparatus according to claim 1, wherein the image recording apparatus is the number of recording data that is actually recorded. 4. The detection means decodes print data in an area smaller than a print area printed by the one scan, and outputs the number of print data actually included in the print data. The image recording apparatus according to claim 1, further comprising a decoding unit. 5. The detecting means decodes print data in an area smaller than a print area smaller than a print area printed in one scan, and is actually recorded in the print data in the smaller area. The first decoding means for outputting the number of print data to be printed, and the number of print data actually printed included in the print data of the smaller area outputted from the first decoding means, to the one scan. The image recording apparatus according to claim 1, further comprising: an addition unit configured to perform the addition over the entire area smaller than the recording area recorded in. 6. The image recording apparatus according to claim 1, wherein the predetermined recording condition includes a type of recording head. 7. The image recording apparatus according to claim 6, wherein the type of the recording head includes a monochrome head for recording black and a color head for recording color. 8. The image recording apparatus according to claim 7, wherein the color head includes a head that outputs each color of yellow, cyan, magenta, and black that records a color. 9. The color head uses a head that outputs each color of yellow, cyan, magenta, and black that records a color, a color mode that outputs a composite color, and a black head of the color heads. The image recording apparatus according to claim 8, further comprising a black mode for outputting black by using the black mode. 10. The image recording apparatus according to claim 1, wherein the recording condition includes an image recording resolution. 11. The image recording apparatus according to claim 10, wherein the resolution includes low resolution and high resolution. 12. The image recording apparatus according to claim 1, wherein the recording unit reduces the number of recording elements used by the recording head per unit time. 13. The image recording apparatus according to claim 1, wherein the recording condition includes a high quality mode for forming a high quality image. 14. The image recording apparatus according to claim 1, wherein the recording condition includes a high speed mode for forming an image at high speed. 15. The image recording apparatus according to claim 1, wherein the recording condition includes a normal mode for forming an image of normal quality. 16. The predetermined threshold value corresponding to the predetermined recording condition is set for each of the combination of the recording head type, the resolution type, the high-quality mode, the high-speed mode, and the normal mode. The image recording apparatus according to any one of claims 6, 10, 13, 14, and 15, which is set correspondingly. 17. An image recording apparatus for recording an image by sequentially scanning a recording head having a plurality of recording elements in a direction different from a conveyance direction of a recording sheet, wherein a recording area to be recorded by one scanning is divided into a plurality of areas. A detection unit that detects the recording duty of the divided area, a comparison unit that compares the recording duty of the divided area with a predetermined threshold value that corresponds to a predetermined recording condition, and a comparison result of the comparison unit and the predetermined recording condition. An image recording apparatus comprising: a recording unit that selects a predetermined area of the recording head based on the above and completes recording for one scan by a plurality of recording scans. 18. The image recording apparatus according to claim 17, wherein the recording head has a plurality of heads capable of simultaneously recording different pixels. 19. The image recording apparatus according to claim 18, wherein the plurality of heads record black pixels. 20. The image recording apparatus according to claim 18, wherein the plurality of heads include a head that outputs each color of yellow, cyan magenta, and black that records a color. 21. The image recording apparatus according to claim 17, wherein the predetermined area of the recording head is an area in units of a plurality of predetermined segments forming the recording head. 22. An image recording apparatus for recording an image by sequentially scanning a recording head having a plurality of recording elements in a direction different from a recording paper conveyance direction, the recording width being based on a type of the recording head and a recording mode. 1
A detection unit that detects a print duty of a divided area obtained by dividing a print area to be printed by scanning, a print duty of the divided area, a type of the print head, and a usage area of the print head based on the print mode. An image recording apparatus comprising: a recording unit that determines and performs recording for one scanning by scanning a plurality of times. 23. The image recording apparatus according to claim 22, wherein the recording head has a plurality of heads capable of simultaneously recording different pixels. 24. The image recording apparatus according to claim 23, wherein the plurality of heads record black pixels. 25. The image recording apparatus according to claim 23, wherein the plurality of heads include a head that outputs each color of yellow, cyan magenta, and black that records a color. 26. An image recording method for recording an image by sequentially scanning a recording head having a plurality of recording elements in a direction different from a recording paper conveyance direction, wherein an area smaller than a recording area to be recorded in one scan is used. A detecting step of detecting a print duty, and a print head used for printing in one scan under the predetermined print condition when the detected print duty is larger than a predetermined threshold value corresponding to a predetermined print condition. An image recording method, comprising a recording step of reducing a load per unit time and completing recording for one scanning by a plurality of recording scans. 27. 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. 26. The image recording method according to 26. 28. The print duty according to claim 26, wherein the print duty is the number of print data actually printed out of print data in an area smaller than a print area printed in one scan. Image recording method. 29. The detecting step decodes print data of an area smaller than a print area printed by the one scan, and outputs the number of print data actually included in the print data. 27. The image recording method according to claim 26, further comprising a decoding step. 30. The detecting step decodes print data in an area smaller than a print area smaller than the print area printed in one scan, and is actually printed in the print data in the smaller area. A first decoding step of outputting the number of print data to be recorded, and the number of print data to be actually printed included in the print data of the smaller area output from the first decode step, 27. The image recording method according to claim 26, further comprising: an addition step of performing addition over the entire area smaller than the recording area recorded in. 31. The image recording method according to claim 26, wherein the predetermined recording condition includes a type of a recording head. 32. The image recording method according to claim 31, wherein the types of the recording head include a monochrome head for recording black and a color head for recording color. 33. The image recording method according to claim 32, wherein the color head includes a head that outputs each color of yellow, cyan, magenta, and black that records a color. 34. The color head uses a head for outputting each color of yellow, cyan, magenta, and black for recording a color, a color mode for outputting a composite color, and a black head of the color heads. The image recording method according to claim 33, further comprising a black mode for outputting black by using the black mode. 35. The image recording method according to claim 26, wherein the recording condition includes a resolution of image recording. 36. The image recording method according to claim 35, wherein the resolution includes a low resolution and a high resolution. 37. The image recording method according to claim 26, wherein in the recording step, the number of recording elements used by the recording head per unit time is reduced. 38. The recording condition comprises a high quality mode for forming a high quality image.
The image recording method described in. 39. The image recording method according to claim 26, wherein the recording condition includes a high speed mode for forming an image at high speed. 40. The image recording method according to claim 26, wherein the recording condition includes a normal mode for forming an image of normal quality. 41. The predetermined threshold value corresponding to the predetermined recording condition is set for each combination of the type of the recording head, the type of the resolution, the high quality mode, the high speed mode, and the normal mode. The image recording method according to any one of claims 31, 35, 38, 39, and 40, which is set correspondingly. 42. An image recording method for recording an image by sequentially scanning a recording head having a plurality of recording elements in a direction different from a conveyance direction of a recording sheet, wherein a recording area to be recorded by one scanning is divided into a plurality of areas. A detection step of detecting the recording duty of the divided area, a comparison step of comparing the recording duty of the divided area with a predetermined threshold value corresponding to a predetermined recording condition, a comparison result in the comparison step and the predetermined recording condition Based on the above, a recording step of selecting a predetermined area of the recording head and completing recording for one scan by a plurality of recording scans is provided. 43. The image recording method according to claim 42, wherein the recording head has a plurality of heads capable of simultaneously recording different pixels. 44. The image recording method according to claim 43, wherein the plurality of heads record black pixels. 45. The image recording method according to claim 43, wherein the plurality of heads include a head that outputs each color of yellow, cyan magenta, and black that records a color. 46. The image recording method according to claim 42, wherein the predetermined area of the recording head is an area in units of a plurality of predetermined segments forming the recording head. 47. An image recording method for recording an image by sequentially scanning a recording head having a plurality of recording elements in a direction different from a conveyance direction of a recording sheet, the recording width being based on a type of the recording head and a recording mode. 1
A detection step of detecting a print duty of a divided area obtained by dividing a print area to be printed by scanning, a print duty of the divided area, a type of the print head, and a use area of the print head based on the print mode. And a recording step of performing recording for one scan by scanning a plurality of times. 48. The image recording method according to claim 47, wherein the recording head has a plurality of heads capable of simultaneously recording different pixels. 49. The image recording method according to claim 48, wherein the plurality of heads record black pixels. 50. The image recording method according to claim 48, wherein the plurality of heads include a head that outputs each color of yellow, cyan magenta, and black that records a color.