JP2986123B2 - Ink jet 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 ink jet recording method and apparatus for performing recording by discharging ink droplets on a recording medium, and more particularly to an ink jet recording method and apparatus for performing thinned multi-pass printing.

[Background of the Invention] In recent years, OA equipment such as computers, word processors, and copying machines have become widespread, and many recording methods for these recording apparatuses have been developed. The ink jet recording apparatus has an excellent feature that high definition is easy, high speed, excellent in quietness, and inexpensive as compared with other recording methods.

In an ink jet recording apparatus, paper, OHP
Various recording modes are prepared in addition to the simple one-scan recording mode for the purpose of preventing the problem of ink fixing property on a recording medium such as a film and the density unevenness inherent to the recording head.

Among such print modes, so-called multi-pass printing, in which the same print head scans the same area on a print medium a plurality of times to perform printing, is often used for various purposes.

For example, when printing is performed on a recording medium having no or very low ink absorption or when performing color recording on a recording medium having low ink absorption using a plurality of recording heads having different ink colors, Ink overflows on the recording medium, causing streaky unevenness (called "beading")
And bleeding at the boundary of different colors and densities ("Border bleeding"
) And image quality may be significantly reduced. In order to prevent "beading" and "border bleeding" due to ink overflow, print data printed by one scan is skipped in a zigzag pattern and multiple thinning patterns are not printed at once. Is performed a plurality of times to perform thinning-out multi-pass printing in which an image corresponding to all print data is finished.

[0006] In this thinning multi-pass printing, (1) the amount of ink printed in each pass is reduced as compared with one-pass printing, and absorption into a recording medium is performed in a short time. In between, the two effects of drying the ink reduce ink overflow, "beading"
It is thought to prevent "border bleed".

FIG. 19 schematically shows a conceptual diagram of a conventional ink jet recording apparatus for performing thinned-out multi-pass printing. In the drawing, reference numeral 1 denotes a recording head, which has a plurality of ink ejection ports and a plurality of electrothermal transducers provided as ejection energy generating elements corresponding to the ink ejection ports. The ink droplets are supplied to the converter, and the ink bubbles are ejected from the ejection ports by causing a change in the state of the ink by the bubbles generated thereby. Reference numeral 2 denotes a carriage for holding a recording head, and 3 denotes a guide shaft for supporting the carriage 2, which is interposed and arranged with a recording medium P intermittently moved in a direction of an arrow (sub-scanning direction) by a sub-scanning roller (not shown). A carriage belt for reciprocating (main scanning) the carriage 2 along the guide shaft 3 and a main scanning motor 5 for driving the carriage belt. Reference numeral 6 denotes a print mode switching unit that switches a print mode by a manual switch operation by a user or automatically, and 7 denotes an input image signal (hereinafter referred to as a print signal) when the thinning multi-pass printing is selected by the print mode switching unit 6. 3) Thinning-out print signal creating means for creating a thinning-out print signal for performing thinning-out multi-pass printing from S, and 8 denotes a head driving means for driving the recording head 1 in accordance with a signal from the thinning-out print signal creating means 7. Reference numeral 9 denotes a main scanning motor driving signal generating unit that generates a signal for driving the main scanning motor. When the printing mode switching unit 6 selects the thinning multi-pass printing,
Drive signals for the number of passes are sequentially created. Reference numeral 10 schematically shows main scanning motor driving means for controlling driving of the main scanning motor 5 by a signal from the motor driving signal generating means.

In such an ink jet recording apparatus, thinning-out multi-pass printing is performed as follows. When the print mode switching means 6 selects the thinning multi-pass printing by the manual switch operation by the user or automatically, the input image signal as shown in FIG. The data is thinned out according to the pattern (FIG. 20B), and is divided into a thinned print signal S1 and a thinned print signal S2 as shown in FIGS. 20C and 20D. First, the thinned print signal S1 is sent to the head driving means 8 to drive the recording head 1, and ink droplets are ejected from the ejection openings of the recording head 1. In synchronization with this (actually, a predetermined time before the head drive), a main scan drive signal for the carriage is generated by the main scan motor drive signal creating means 9 and the main scan motor is driven according to the signal from the drive means. , Carriage 2
Moves along the guide shaft 3 to perform the first pass printing. After the printing is completed, the main scanning motor 5 is driven in the reverse direction, and the carriage 2 returns to the start position. further,
After a lapse of a predetermined time (hereinafter referred to as a multi-pass print interval), the thinned print signal S2 remaining by the thinning is sent to the head driving means 8 to drive the print head 1, and the second pass is performed in the same manner as the first pass. After printing, prepare for printing the next line.

During this time, a sub-scanning roller (not shown) is controlled so that the recording medium does not move, so that thinning two-pass printing is realized. In the above description, the case of thinning two-pass printing has been described.
It will be described similarly.

[0010]

When performing thinning multi-pass printing as described above, the number of multi-pass printings and the multi-pass printing interval are assumed to be used in order to prevent the ink from overflowing on the recording medium. In an environment where the ink drying speed is the slowest among the environmental conditions, the setting is usually such that “bleeding” does not occur when the assumed highest ink density is printed on the recording medium.

Therefore, when thinning multi-pass printing is performed, the time required for printing does not change even when used in an environment where the ink drying speed is high, or when printing with a low ink density, and is unnecessary. There was a problem that the throughput was reduced.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and has as its object to provide an ink jet recording method and apparatus capable of recording a high quality image on a recording medium without unnecessary decrease in throughput. .

[0013]

Means and Action for Solving the Problems That is, the present invention provides:
In an ink-jet recording method in which ink is ejected from a recording means having a plurality of ejection elements onto a recording medium to record characters or figures, a desired image is obtained by recording a thinned image a plurality of times in the same area of the recording medium. It is another object of the present invention to provide an ink jet recording method characterized by appropriately controlling a recording interval at the time of the plurality of recordings according to a predetermined condition.

The present invention is also an ink jet recording method for recording a color image using a plurality of recording means for discharging inks of different colors, wherein a thinned color image is recorded a plurality of times in the same area of a recording medium. In this way, a desired color image is obtained, and the print ink density of the mixed-color printing section is predicted based on the print duty of each color recording unit, and the recording interval at the time of the multiple recording is changed according to the predicted value. The present invention provides an ink jet recording method characterized by the following.

According to the present invention, there is provided a recording means including a plurality of ejection elements for ejecting ink onto a recording medium, a data generating means for generating a plurality of thinned-out image data from desired image data, Means for recording a thinned image a plurality of times in the same area of the recording medium based on the thinned image data output from the means, and control means for appropriately controlling a recording interval in the plural times of recording in accordance with a predetermined condition The present invention provides an ink jet recording apparatus characterized by having the following.

According to the present invention, a plurality of recording means having a plurality of ejection elements for ejecting ink droplets of different colors to a recording medium, and a plurality of thinned image data for each color are generated from desired image data. Data generating means, means for recording a thinned image a plurality of times in the same area of the recording medium based on a plurality of thinned image data output from the data generating means by the recording means, print duty of each of the plurality of recording means Control means for appropriately controlling the recording interval at the time of the plurality of recordings based on the above.

According to the present invention, a plurality of thinned images are recorded at an appropriate interval based on a predetermined condition in the same area of a recording medium a plurality of times to obtain a desired image without blurring.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

The present invention is not limited to the embodiments described below, but includes various modifications as long as they fall within the scope described in the claims.

First Embodiment FIG. 1 shows a conceptual diagram of an ink jet recording apparatus applied to the present invention. In the figure, reference numerals 1 to 6 denote constituent members similar to those in FIG. Reference numeral 17 denotes a print duty detecting means for detecting a maximum print duty in one line of the print signal S, and reference numeral 18 determines a multi-pass print interval according to a signal from the print duty detecting means 17, and creates a multi-pass interval control signal. Multipass interval control signal generating means, 19 denotes a thinned-out print signal generating means, 20 denotes a head driving means, 21 denotes a main scanning motor driving signal generating means, and 22 denotes a main scanning motor driving means.

The control of the multi-pass printing interval by the printing duty by the ink jet recording apparatus having such a configuration is performed as follows.

When the print mode switching means 6 selects thinning multi-pass printing by a manual switch operation by a user or automatically, an input image signal is first sent to a print duty detecting means 17 and the print duty of one line is determined. The maximum value is detected, and the detected maximum value is sent as a signal to the multipath interval control signal creating means 18.

The method of detecting the maximum value of the print duty in this embodiment is as follows.

As shown in FIG. 2A, assuming a pixel range B (hatched portion in the figure) having a specific number N of pixels (N = 9 in this embodiment), the number of print pixels within the range is assumed. n (FIG. 2 (a)
In the range B, n = 1) is checked, and n / N is calculated to be the print duty D at the center pixel C. The printing duty determined in this way is obtained for all the pixels in the printing area, and the maximum value is set as the maximum value of the printing duty in one line. In the case of the print pattern illustrated in FIG.
FIG. 2B shows the print duty of each pixel obtained by the above method. In this case, the maximum value of the print duty is D = 9/9 (= 1) at the pixel surrounded by the thick line in FIG.
00%).

The multi-pass interval control signal creating means 18 determines the multi-pass interval according to the signal indicating the maximum print duty input from the print duty detecting means 17, and creates a multi-pass interval control signal. This signal is sent to the thinned-out print signal creating means 19. The multi-pass interval is determined based on, for example, a table showing the correspondence between the maximum print duty and the multi-pass print interval (arbitrary unit in FIG. 3) as shown in FIG. 3, and printing is performed at the determined multi-pass interval. A multi-pass interval control signal for controlling the transfer interval of the thinned-out print data is created and sent to the thinned-out print signal creating means 19. In the thinned-out print data creating means 19, the print signal is divided into a thinned-out print signal S1 and a thinned-out print signal S2 in the same way as in FIG. Then, the recording head 1 is driven.
Further, in synchronization with this, the main scanning motor drive signal generating means 21
Then, a main scanning motor drive signal is created, sent to the main scanning motor control means 22, and the main scanning motor 5 is driven to move the carriage 2 to perform two-pass printing on the first line.

In our experiment, a bubble ink jet head (360 dpi, 5 kHz drive) of a printer BJ330 manufactured by Canon Inc. was used as a recording head, black ink of the printer was used as ink, and polyvinyl alcohol (PET) was used as a recording medium on a polyethylene terephthalate (PET) film. An experiment was carried out in an environment at a temperature of 35 ° C. and a relative humidity of 90% using 2 μm of PVA). When a solid image was printed by conventional thinning-out 2-pass printing, the first pass and the second pass were performed. Unless the interval between them was not less than 3 seconds, the above-mentioned occurrence of beading could not be prevented. When the conventional thinning printing pass method is used, if the pass interval of two-pass printing is set to 3 seconds, A4
It takes about 200 seconds longer printing time per sheet than in one-pass printing.

However, according to our experiment, the pass interval required to prevent the occurrence of "beading" when performing two-pass printing tends to be shorter as the print duty is lower, as shown in the graph of FIG. . Therefore, a table of the maximum print duty and the pass interval as shown in the table of FIG. 5 was created, and the multi-pass interval control described in the above embodiment was performed. At this time, when the upper half of the A4 size image is a 100% solid image and the lower half is an image with a print duty of 30%, the print image is about 1% smaller than the conventional thinned multi-pass print.
Time saving of 00 seconds is possible, and "beading"
Thus, an image having no image quality deterioration was obtained, and a great effect was exhibited.

Note that the required pass interval in FIG. 4 does not include the time t from when the carriage 2 returns to the home position after the start of printing in the first pass and when scanning in the second pass becomes possible. Therefore, the pass interval is actually longer by the time t than the time obtained from FIG. 5 based on the maximum print duty.

[Second Embodiment] Next, another embodiment of the present invention will be described.

FIG. 6 shows an embodiment in which the present invention is applied to an ink jet recording apparatus for recording a color image having a plurality of recording heads for ejecting inks of different colors.

In the drawing, reference numerals 31K, 31C, 31M, and 31Y denote recording heads that eject black, cyan, magenta, and yellow inks, 32 denotes a carriage that holds these four recording heads, and 37 denotes a color mixing unit of the present invention. 2 shows a printing ink density detecting unit. Incidentally, reference numerals 3 to 6 and 18 to 22 denote constituent members similar to those in FIG.

The control of the multi-pass printing interval by the printing duty by the ink jet recording apparatus having such a configuration is performed as follows.

When the print mode switching means 6 selects thinning multi-pass printing by manual switch operation or automatic by the user, the input image signal is first sent to the mixed color portion printing ink density detecting means 37, and the input image signal is sent to one line. The maximum value of the print ink density is predicted, and the predicted maximum value is sent as a signal to the multi-pass interval control signal creating means 8.

The method of estimating the maximum value of the printing ink density in the mixed color portion of the color image in this embodiment is as follows.

First, the print duty per pixel for each color is determined by the method described with reference to FIG. 2 of the first embodiment. Next, the print duties per pixel of the same pixel of each color are added together to obtain the mixed color print duty of the pixel, and this is regarded as the density of the mixed color print ink in each pixel, and the maximum value is obtained. FIG. 7 shows an example. In the drawing, regarding the pixel of interest (the pixel surrounded by a thick line), the K print duty is 6/9, the C print duty is 4/9, the M print duty is 0/9, and the Y print duty is 5/9.
The desired mixed color printing duty (that is, printing ink density) is
6/9 + 4/9 + 0/9 + 5/9 = 15/9.

The multi-pass interval control signal generating means 18 determines the multi-pass interval in accordance with the signal indicating the maximum print duty input from the mixed color portion printing ink density detecting means 37, and generates a multi-pass interval control signal. This signal is sent to the thinned-out print signal creating means 8. In the thinned-out print data creating means 9, the print signals are converted to thinned-out print signals S1 (for four colors) and thinned-out print signals S2 in the same manner as in FIG.
(For four colors), which are sequentially sent to the head driving means 20 at corresponding time intervals according to the multipath interval control signal, and the recording heads 31K, 31C, 31M, and 31Y are driven. In synchronization with this, the main scanning motor drive signal generating means 21 generates a main scanning motor drive signal and sends it to the main scanning motor control means 22 to drive the main scanning motor 5 to move the carriage 32 to move the first line. Two-pass printing is performed.

In our experiment, a bubble ink jet head (360 dpi, 5 kHz drive) of a printer manufactured by Canon BJ330 was used as a recording head, and black and cyan, magenta, and black ink of the same printer were used as inks. Color ink mixed with yellow dye, PPC paper as recording medium, temperature 3
Experiments were conducted in an environment of 5 ° C. and a relative humidity of 90%. As a result, with conventional thinning 2-pass printing and 100% solid two-color mixed printing, “border bleeding” occurred at different color boundaries, resulting in poor image quality. Because of the remarkable decrease, a satisfactory image could not be obtained unless the interval between the first pass and the second pass was made longer than 6 seconds. When using the conventional thinning printing pass method, if the pass interval for 2-pass printing is set to 6 seconds, the printing time is about 400 seconds per A4-size sheet compared to 1-pass printing regardless of the printing ink density. Will take a lot of time.

However, according to our experiment, as shown in the graph of FIG. 8, the pass interval required to prevent the occurrence of “border bleeding” during two-pass printing becomes sharper as the maximum print ink density becomes lower. Tends to be shorter. Therefore, a table of the maximum ink density and the pass interval as shown in the table of FIG.
The multipath interval control described in the above embodiment was performed. At this time, as the print image, the upper half of the A4 size is a solid 100%.
%, And the lower half prints a two-color image with a print duty of 30%, which takes about 200 seconds compared to the conventional thinning multi-pass printing. The time can be reduced, and an image free from image quality deterioration such as "border blur" can be obtained, and a great effect is exhibited.

In this embodiment, the path interval is actually longer than the time obtained from FIG. 9 by the time t.

[Third Embodiment] FIG. 10 shows a third embodiment of the present invention. In the drawing, those denoted by the same reference numerals as those in FIG. 6 are the same components. 47 is a relative humidity detecting device (semiconductor humidity sensor or the like) provided on the carriage 32, 48 is a relative humidity detecting means for receiving a signal from the relative humidity detecting device 47 and detecting the relative humidity near the recording section, and 49 is a relative humidity detecting device. A multi-pass interval control signal creating unit that determines a multi-pass interval according to a signal from the humidity detecting unit and creates a multi-pass interval control signal;
Is a thinned-out print signal creating means, 51 is a head driving means, 5
Reference numeral 2 denotes a main scanning motor driving signal generating unit, and 53 denotes a main scanning motor driving unit.

The control of the multi-pass printing interval by the printing duty by the ink jet recording apparatus having such a configuration is performed as follows.

When the printing mode switching device selects thinning multi-pass printing by a manual switch operation by a user or automatically, the relative humidity detecting means 48
Drives the relative humidity detector 47 to detect the relative humidity in the vicinity of the relative humidity detector 47 and sends it to the multipath interval control signal creation means 49 as a signal. The multipath interval control signal creating means 49 determines the multipath interval according to the input relative humidity signal, creates a multipath interval control signal, and sends the signal to the thinned print data creating means 50. The multi-pass interval is determined based on, for example, a table showing the correspondence between the relative humidity and the multi-pass printing interval (arbitrary unit in FIG. 11) as shown in FIG. 11, and printing is performed at the determined multi-pass interval. A multi-pass interval control signal for controlling the transfer interval of the thinned-out print data is created and sent to the thinned-out print signal creating means 50.

In the thinned print data generating means 50, the print signal is divided into a thinned print signal S1 (for four colors) and a thinned print signal S2 (for four colors) in the same manner as in FIG. The heads are sequentially sent to the head driving unit 51 at corresponding time intervals to drive the head. In synchronization with this, the main scanning motor drive signal generating means 52 generates a main scanning motor drive signal and the main scanning motor control means 5
3, the main scanning motor 5 is driven to move the carriage, and two-pass printing of the first line is performed.

In our experiments, a bubble ink jet head (360 dpi, 5 kHz drive) of a printer manufactured by Canon Canon BJ330 was used as a recording head, and black and cyan ink, magenta ink and clear ink (ink excluding dye) of the printer were used as ink. Color ink mixed with yellow dye, PPC paper as recording medium, temperature 3
Experiments were conducted in an environment of 5 ° C. and a relative humidity of 90%. As a result, with conventional thinning 2-pass printing and 100% solid two-color mixed printing, “border bleeding” occurred at different color boundaries, resulting in poor image quality. Because of the remarkable decrease, a satisfactory image could not be obtained unless the interval between the first pass and the second pass was made longer than 6 seconds.

In the case of using the conventional thinning printing pass method, if the pass interval of two-pass printing is set to 6 seconds, it takes about 400 seconds per A4 size sheet per sheet, regardless of the printing ink density. It takes a lot of time for printing.
However, according to our experiments, the pass interval required to prevent the occurrence of “border bleeding” when performing two-pass printing is 35 ° C.
In the environment, as shown in the graph of FIG. 12, the lower the relative humidity in the vicinity of the print portion, the shorter the relative humidity tends to be. Therefore,
A table of the relative humidity and the path interval as shown in the table of FIG. 13 was created, and the multipath interval control described in the above embodiment was performed. At this time, as a print image, an entire A4 size solid 10
When an image in which block patterns are arranged so that different colors are arranged side by side in a mixed color of 0% is printed in an environment of a relative humidity of 50%, it is about 2 times less than the conventional thinning multi-pass printing.
The time can be reduced by 00 seconds, and an image free from image quality deterioration such as “border bleeding” can be obtained.

In this embodiment, the path interval is actually longer than the time obtained from FIG. 13 by the time t.

[Fourth Embodiment] FIG. 14 shows a fourth embodiment of the present invention. 6, the same reference numerals as those in FIGS. 6 and 10 denote the same components, and 54 denotes a multi-pass interval control signal generating means, which is based on a signal from the humidity detecting means 48 and a signal from the mixed color portion printing ink density detecting means 54. To determine a multi-pass printing interval to create a multi-pass interval control signal. This signal is sent to the thinned-out print data creating means 50, and multi-pass printing is performed in the same manner as in the third embodiment.

Here, the relationship between the relative humidity and the multi-pass interval when the print ink density is used as a parameter has characteristics as shown in FIG. That is, the higher the printing ink density, the longer the multi-pass interval, and the higher the humidity even at a constant printing ink density, the longer the multi-pass interval. Therefore, based on this characteristic, a table of the maximum ink density and the relative humidity is created in the same manner as in the previous embodiment, and a table of the pass intervals is created.
The multipath interval may be controlled.

[Fifth Embodiment] FIG. 16 shows an embodiment in which the present invention is applied to a multi-pass printing method in which four colors are sequentially printed. 6, the same reference numerals in FIG. 6 denote the same constituent members, 67 denotes a print duty detecting means of the present invention,
8 is a multipath interval control means, and 69 is a multipath interval control signal creation means.

The control of the multi-pass printing interval by the ink jet recording apparatus having such a configuration is performed as follows. When the print mode switching means 6 selects thinning multi-pass printing by a manual switch operation by a user or automatically, an input image signal is first sent to the printing ink duty detecting means 67, and one for each color.
The maximum print duty in the line is detected in the same manner as in the first embodiment. The detected maximum printing duty is sent as a signal to the multi-pass interval control signal creating means 69. The multi-pass interval control signal creating means 69 determines a multi-pass interval according to the input maximum printing duty of each color, creates a multi-pass interval control signal, and sends the signal to the multi-pass interval control means 68.

As means for determining the multi-pass interval from the maximum print duty of each color, a table of the maximum print duty and the multi-pass interval is created in the same manner as in the above-described embodiment based on the maximum print duty of the color to be printed. Then, the multipath interval is determined based on this.

The print signals SY, SM, SC, and SK sent to the multi-pass interval control means 68 are sequentially sent to the head drive means 20 one color per pass at a multi-pass interval determined by the multi-pass interval control signal. Transferred to the recording head 31
Y, 31M, 31C and 31K are driven. In synchronization with this, a main scanning motor driving signal is created in the main scanning motor driving means 21 and sent to the main scanning motor driving means 22 to drive the main scanning motor to move the carriage 32 to print the first line in the 4-pass printing. Is performed.

In our experiment, a bubble ink jet head (360 dpi, 5 kHz drive) of a Canon printer BJ330 was used as a recording head, and black and cyan ink, magenta ink and clear ink (ink excluding dye) of the printer were used as ink. Color ink mixed with yellow dye, PPC paper as recording medium, temperature 3
In the environment of 5 ° C. and a relative temperature of 90%, four-pass printing was sequentially performed in the order of cyan, magenta, yellow, and black. In the mixed printing of 100% solid two colors, “border bleeding” occurred at different color boundaries. And the image quality was remarkably deteriorated, so that a satisfactory image could not be obtained unless the interval between each pass was at least 6 seconds. When using the conventional thinning printing pass method, if the interval between each pass is set to 6 seconds, it takes about 1200 seconds more printing time per A4 size sheet than 1 pass printing regardless of the printing duty. Become.
However, according to our experiment, as shown in the graph of FIG. 17, 100% solid printing is first performed for the pass interval required to prevent the occurrence of “border bleeding” when performing color sequential multi-pass printing. In such a case, the lower the maximum printing duty to be printed later, the shorter the printing duty tends to be. Therefore, a table of the maximum print duty and the multi-pass interval as shown in the table of FIG. 18 was created, and the above-described multi-pass interval control was performed. At this time, as the print image, the upper half of the A4 size is a solid 100%.
%, And the lower half prints a two-color image with a print duty of 30%, which takes about 800 seconds compared to the conventional thinned multi-pass printing. The time can be reduced, and an image free from image quality deterioration such as "border blur" can be obtained, and a great effect is exhibited. Further, there is no need to know the ink density in the mixed color portion, and there is no need to create thinned-out print data, so that there is also an effect that an electric circuit is not required and the cost can be significantly reduced.

[Other Embodiments] In the above embodiment, when performing color image recording, it is more effective to control the multi-pass interval differently depending on the difference between a single color and a mixed color. For example, when the “border bleed” is conspicuous, such as at the boundary between yellow and black, it is necessary to increase the pass interval as compared with the others, or to change the print duty of each color added when calculating the print ink density. It is conceivable that weighting is performed.

For example, in the fifth embodiment, the same pass interval is set for each color at the time of color sequential multi-pass printing. However, if a different multi-pass interval is set depending on the color, it is more effective. "Boundary blur" can be prevented.
In experiments, when performing four-pass printing in order of cyan, magenta, yellow, and black in order of color, it is possible to effectively prevent "border bleed" by setting the printing interval of yellow and black longer than others to make "border bleed" more conspicuous. Was.

In the above-described embodiment, as an example of thinning multi-pass printing, a method of thinning multi-pass printing of print data for each single color in a zigzag or inverted zigzag manner has been described. .

In the above-described embodiment, the print duty detecting means and the printing ink density estimating means are placed before the thinned-out print data creating means. If the multipath interval is finely controlled by each signal, an even higher effect is exhibited.

Further, in the above-described embodiments, it has been described that the control of the multi-pass interval is performed independently. However, a plurality of signals of (monochromatic) print duty, (mixed color) print ink density, and relative humidity are used. It goes without saying that finer control of the multipath interval is more effective.

Further, the control of the multi-pass interval according to the difference in the type of the recording medium (PPC paper and ink-coated paper) and the difference in the recording mode (two-pass and four-pass, etc.) is also used. May be.

In the first embodiment, the control is performed using the maximum value of the print duty. However, the control may be performed by detecting the average value of the entire line.

Further, in the third embodiment, when the means for detecting not only the relative humidity but also the temperature is used to finely control the multi-pass interval based on both the relative humidity and the temperature in the vicinity of the recording section, a higher effect is exhibited. You.

[Others] It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for discharging ink, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When this drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are appropriately performed immediately, so that the ejection of the liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in each of the above-mentioned specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, the recording head fixed to the apparatus main body or the electric connection with the apparatus main body or the ink from the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

Further, it is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like provided as a configuration of the printing apparatus in the present invention, since the effects of the present invention can be further stabilized. . If these are specifically mentioned, capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof, Performing a preliminary ejection mode in which ejection is performed separately from printing is also effective for performing stable printing.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or below and which softens or liquefies at room temperature, or an ink jet system In general, the temperature of the ink itself is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Anything can be used. In addition, the temperature rise due to thermal energy can be positively prevented by using it as energy for changing the state of the ink from a solid state to a liquid state, or ink that solidifies in a standing state to prevent evaporation of the ink can be used. In any case, the ink is liquefied by the application of the thermal energy according to the recording signal, and the ink is liquefied, and the liquid ink is discharged. The present invention is also applicable to a case where an ink that liquefies for the first time by energy is used. In such a case, the ink is disclosed in JP-A-54-56847 or JP-A-60
As described in JP-A-71260, a configuration may be adopted in which a liquid or solid substance is held in a concave portion or through hole of a porous sheet and opposed to an electrothermal converter. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also for a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. It may take a form.

[0070]

As described above, according to the present invention, the recording interval when a desired image is obtained by recording a thinned image a plurality of times in the same area of a recording medium depends on predetermined conditions such as print duty and environmental conditions. And appropriate control, it is possible to obtain a high-quality image without blurring without lowering the throughput.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an ink jet recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a method for obtaining a print duty.

FIG. 3 is a diagram showing a table indicating a correspondence between a maximum printing duty and a multi-pass printing interval.

FIG. 4 is a diagram showing a relationship between a print duty and a pass interval necessary for preventing occurrence of beading.

FIG. 5 is a diagram illustrating a correspondence between a maximum print duty and a multi-pass interval.

FIG. 6 is a conceptual diagram of an ink jet recording apparatus according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating a method for obtaining a mixed-color printing duty.

FIG. 8 is a diagram illustrating a relationship between a print ink density and a required pass interval.

FIG. 9 is a diagram showing a correspondence between a maximum print ink density and a pass relationship.

FIG. 10 is a conceptual diagram of an ink jet recording apparatus according to a third embodiment of the present invention.

FIG. 11 is a diagram showing the correspondence between relative humidity and multipath intervals.

FIG. 12 is a diagram illustrating a relationship between relative humidity and a required path interval.

FIG. 13 is a diagram showing the correspondence between relative humidity and multipath intervals.

FIG. 14 is a conceptual diagram of an ink jet recording apparatus according to a fourth embodiment of the present invention.

FIG. 15 is a diagram illustrating a relationship between a relative humidity and a pass interval when a print ink density is used as a parameter.

FIG. 16 is a conceptual diagram of an ink jet recording apparatus according to a fifth embodiment of the present invention.

FIG. 17 is a diagram illustrating a relationship between a print duty of a post-strike color and a multi-pass interval.

FIG. 18 is a diagram illustrating a correspondence between a maximum print duty and a multi-pass interval.

FIG. 19 is a conceptual diagram of a conventional inkjet recording apparatus that performs multi-pass printing.

FIG. 20 is a diagram illustrating a thinning pattern.

[Explanation of symbols]

 1, 31Y, 31Y, 31C, 31K Recording head 2, 32 Carriage 3 Guide shaft 4 Carriage belt 5 Main scanning motor

Continued on the front page (72) Inventor Miyuki Matsubara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shigetasu Nagoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yuji Akiyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-4-21466 (JP, A) JP-A-4-37250 (JP, A JP-A-4-259566 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2/205 B41J 2/05 B41J 2/21 B41J 2/485

Claims (19)

(57) [Claims] An ink jet recording method in which ink is ejected from a recording means having a plurality of ejection elements onto a recording medium to record characters or graphics, etc., by recording a thinned image multiple times in the same area of the recording medium. An ink jet recording method comprising: obtaining a desired image; and appropriately controlling a recording interval during the plurality of recordings according to a predetermined condition. 2. The ink jet recording method according to claim 1, wherein a recording interval at the time of the plurality of recordings is changed according to a print duty of the recording unit. 3. The ink jet recording method according to claim 1, wherein an environmental condition near the recording unit is detected, and the recording interval is changed according to the detected environmental condition. 4. The ink jet recording method according to claim 3, wherein at least one of temperature and relative humidity near the recording section is detected as the environmental condition. 5. The ink jet recording method according to claim 1, wherein the recording interval is determined based on a table indicating a correspondence between the predetermined condition and the recording interval. 6. The ink jet recording method according to claim 1, wherein said recording means causes the ink to eject by causing a state change in the ink by thermal energy. 7. An ink jet recording method for recording a color image by using a plurality of recording means for discharging inks of different colors, wherein a thinned color image is recorded a plurality of times in the same area of a recording medium. A color image is obtained, and the print ink density of the mixed-color printing unit is predicted based on the print duty of each color recording unit, and the recording interval during the multiple recording is changed according to the predicted value. Inkjet recording method. 8. The ink jet recording method according to claim 7, wherein the recording interval is determined based on a table indicating a correspondence between the printing duty and the recording interval. 9. The ink jet recording method according to claim 6, wherein said recording means causes a state change in the ink by thermal energy to discharge the ink. 10. A recording unit having a plurality of ejection elements for ejecting ink to a recording medium, a data generation unit for generating a plurality of thinned image data from desired image data, and an output from the data generation unit by the recording unit Means for recording a thinned image a plurality of times in the same area of the recording medium based on the thinned image data to be performed, and control means for appropriately controlling a recording interval in the plurality of times of recording in accordance with a predetermined condition. An ink jet recording apparatus comprising: 11. The apparatus according to claim 10, wherein said control means includes a detection means for detecting a print duty of said recording means, and changes said scanning interval according to a detection signal from said detection means. Ink jet recording device. 12. When the detection signal indicates that the printing duty is higher than a predetermined value, the control means sets the scanning interval to a first interval and determines that the printing duty is lower than a predetermined value. The ink jet recording apparatus according to claim 11, wherein a second interval shorter than the first interval is set when the detection signal indicates. 13. The apparatus according to claim 1, wherein said control means includes a detection means for detecting an environmental condition near a recording position of said recording means, and changes said scanning interval according to a detection signal from said detection signal. An ink jet recording apparatus according to claim 10. 14. An ink jet recording apparatus according to claim 13, wherein said detecting means is at least one of a temperature and a relative humidity near said recording position. 15. The ink jet recording apparatus according to claim 10, wherein the control unit determines the recording interval based on a table indicating a correspondence between the predetermined condition and the recording interval. 16. The recording apparatus according to claim 10, wherein the recording means causes a state change in the ink by thermal energy to discharge the ink.
Item 6. The ink jet recording apparatus according to item 1. 17. A plurality of recording means having a plurality of ejection elements for ejecting ink droplets of different colors to a recording medium, and a data generation means for generating a plurality of thinned image data for each color from desired image data. Means for recording a thinned image a plurality of times in the same area of the recording medium based on a plurality of thinned image data output from the data generating means by the recording means, based on a print duty of each of the plurality of recording means An ink jet recording apparatus, comprising: control means for appropriately controlling a recording interval at the time of the plural times of recording. 18. The ink-jet recording apparatus according to claim 17, wherein said control means determines said recording interval based on a table indicating a correspondence between said printing duty and said recording interval. 19. The ink jet recording apparatus according to claim 17, wherein said recording means causes a state change of the ink by thermal energy to discharge the ink.