JP2002326347A - Apparatus and method for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder which records uniform images without a density change without conducting suction of a large amount and preliminary discharge even when a non printing state continues for a long time. SOLUTION: For example, when it is judged that a predetermined time indicating a non recording time has passed (S13, S14 and S15), a density signal is corrected to decrease the value with the use of a correction table corresponding to the judgment (S16, S17 and S18). Recording by a predetermined amount at least at a recording start time is carried out on the basis of the corrected density signal. Therefore, even when recording is carried out at the recording start time with an ink having a dye concentration or the like increased during the non recording time, the density is decreased as a whole of the predetermined amount of recording and can be agreed approximately with a density when recording is carried out with a normal-concentration ink.

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 apparatus and an ink-jet recording method, and more particularly to a method for correcting a density in a case where recording is carried out with an ink having a high dye density due to an increase in viscosity during non-printing time. Things.

[0002]

2. Description of the Related Art In a recording apparatus for forming an image using a recording head in which a plurality of recording elements are arranged, there have already been proposed some methods of converting original recording data into signal values for correction.

In particular, in an ink jet recording apparatus that forms an image by discharging ink droplets from each recording element called a nozzle, the discharge amount of each nozzle tends to vary, and as a result, density unevenness is likely to be sensed. As a method for solving this problem, there is a method for correcting density unevenness by performing signal value conversion for each recording element.

This method has already been disclosed in Japanese Patent Application Laid-Open No. 8-108547. In the process, first, a test pattern recorded by each nozzle on the recording head is irradiated with light from a light source and its reflected light is read. Thereby, the density unevenness of the test pattern, that is, the variation of the printing characteristics of each nozzle is detected. Further, the density signal for each nozzle is converted based on the detected value, and as a result, the density unevenness of the image is reduced. This method is called a so-called head shading method. Here, the conversion of the input signal is performed by updating a plurality of correction tables provided in advance.

In this method, even when the print ratio changes rapidly due to the frequency of the nozzles used, or when the print ratio changes to a low print ratio or a high print ratio, the density changes in the entire range from low density to high density. The contents which can correct unevenness are disclosed. Furthermore, there is an example that discloses a technique for updating a correction table even during image formation.

[0006]

In an ink jet recording apparatus, when the recording head is left for a long time, water evaporates from the tips of the nozzles arranged as ink flow paths in the recording head, and the viscosity of the ink is reduced. And the phenomenon that the dye concentration increases. If the ink is further left in this state, the ink having the increased viscosity will clog the nozzles, and eventually will form a non-discharge nozzle that cannot be printed. Further, if the ink viscosity and the dye concentration are slightly increased, even if the ink does not reach the non-discharge nozzle, even if the ink can be ejected, the image is recognized as having a higher density than usual. Then, for example, several dots or several lines immediately after the start of printing have a high density, and a density change such that the density returns to a normal density after the thickened ink is consumed to some extent by ejection is sensed, causing a problem on an image.

One solution to this problem is to remove the thickened ink having a high density existing in the head. Therefore, the density is increased by preliminary ejection or suction before the start of printing.
What is necessary is just to discard the ink with high viscosity. In particular, suction recovery is an effective means for recovering printing even for nozzles that have become non-discharge nozzles due to thickened ink.

[0008] However, ink may be unnecessarily consumed by the preliminary ejection for the nozzles capable of printing, and this is not always a reasonable solution.

Further, in the conventional head shading method, even if the density variation between the nozzles arranged in the head is suppressed, it is not possible to cope with the temporary density unevenness immediately after the start of printing as described above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object thereof is to perform a large amount of suction or preliminary ejection without performing a long time non-printing state even when a non-printing state continues. An object of the present invention is to provide an ink jet recording apparatus and an ink jet recording method for recording a uniform image without a change in density.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an ink jet recording apparatus which performs recording using a recording head in which a plurality of nozzles for ejecting ink droplets are arranged. Time measuring means for measuring an elapsed time until the start; a plurality of density correction tables for converting a density signal to a value lower than a density value indicated by the density signal; and a plurality of correction tables according to the elapsed time. Selecting means for selecting one, and control means for recording at least a predetermined amount to be recorded at the start of the recording based on the density signal corrected using the correction table selected by the selecting means. It is characterized by.

Further, in an ink jet recording method for performing recording using a recording head in which a plurality of nozzles for discharging ink droplets are arranged, a plurality of density corrections for converting a density signal into a value lower than a density value indicated by the density signal. A table is prepared, the elapsed time from the previous recording to the start of recording is measured, one of the plurality of correction tables is selected according to the elapsed time, and a correction is made using the correction table selected by the selection. A step of recording at least a predetermined amount to be recorded at the start of the recording based on the density signal thus obtained.

According to the above arrangement, the density signal is corrected so that its value becomes smaller, for example, using a correction table corresponding to the elapsed time indicating the non-recording time, and at least recording is performed based on the corrected density signal. Since a predetermined amount of recording is performed at the start, even when recording is performed with ink whose density such as occupation has increased during the non-recording at the start of recording, the density of the predetermined amount of recording is reduced as a whole. Can be made to substantially match the density recorded with the ink having the density of

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the ink jet recording apparatus according to the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing the structure of an ink jet recording apparatus according to the present invention. 101
Denotes a recording head, which is composed of an ink tank in which a single color ink or a plurality of color inks are respectively enclosed, and a multi-head in which heads corresponding to the respective inks are integrated. Reference numeral 102 denotes a recovery processing unit, which is a place where ink suction, capping, and preliminary ejection of the recording head 101 are performed. A belt 103 reciprocates the recording head 101 in the X direction together with recording. Reference numeral 104 denotes a paper feed roller which rotates while holding down the recording paper 106 and feeds the recording paper 106 in the Y direction as needed. Also one
Reference numeral 05 denotes a paper feed roller that feeds the recording paper 106 and, like the paper feed roller 104,
The role of suppressing.

FIG. 2 is a block diagram relating to data control of the ink jet recording apparatus according to the present invention. Reference numeral 201 denotes an image data input unit, which serves as a receiving port when print data enters from outside. 203 is a time measuring unit (timer)
The elapsed time from the last printing to the next printing, that is, the time when the recording apparatus is not used is measured.

Reference numeral 205 denotes a correction table for referring to correction values, which are prepared in several stages so that selection can be made according to the elapsed time measured at 203 or the recording amount at each time. The correction table 205 may be configured to be able to simultaneously perform, for example, head shading for correcting the density variation for each nozzle. In this case, one set of correction table for each nozzle for the purpose of head shading is provided,
What is necessary is that a configuration is provided in which a plurality of sets of the above-mentioned correction tables are provided for correction for each elapsed time.

Reference numeral 202 denotes a control unit which transfers the input image data to the image processing unit 204. At this time, as will be described later, control is performed to selectively instruct the correction table 205 to the image processing unit 204 in accordance with the elapsed time from the previous printing measured by the time measuring unit 203. The image processing unit converts the received image data based on the selected correction table, and transfers the final print data to the print head 101.

FIG. 3 is a view showing a recording state in the case where solid printing with a single color is performed without performing a recovery operation or preliminary ejection after a long non-printing state. “The phenomenon that the ink density increases immediately after the start of printing caused by the passage of time” means that even though all the same density data is recorded as the print data, the print density after printing starts as shown in the print example 301 in FIG. The several lines indicate the phenomenon that the density increases. This high-density portion is considered to be a portion recorded with the ink having a high dye concentration due to increased viscosity as a result of being left for a long time. Then, as the recording proceeds, the thickened ink is consumed, so that the density gradually returns to the normal density.

FIG. 4 is a graph illustrating a state in which the density of the ink changes according to the idle time in the non-printing state. The horizontal axis represents the time during which the printing is left in the non-printing state, and the vertical axis represents the density of the print head when solid printing is performed after the printing. From this graph, it can be seen that the ink density tends to be saturated when the elapsed time exceeds 25 hours.

FIG. 5 is a diagram showing how the recording density of each print line changes when solid printing, that is, printing at 100% duty is performed over the entire A4 width paper with respect to the elapsed time. . In the figure, + X% shown under each condition indicates what percentage of the recording density is increased as compared with the standard density when printing is performed using ink that has not been thickened.

According to this figure, when the elapsed time from the last printing is 5 to 12 hours, the printing on the first line is recognized in a state where the density on the recording medium is increased by about 5%. Next, it can be seen that the desired density is obtained in the printing of the second line, and the desired density is obtained in the subsequent printing.

The elapsed time from the last printing is 1
In the case of 2 to 24 hours, the first line is recognized in a state where the density on the recording medium is increased by about 15%. Next, in the printing of the second line, the image is recognized in a state where the density is increased by about 5%, and the desired density is obtained in the third line.

The time elapsed since the last printing is 2
In the case of 4 hours or more, the first line is recognized in a state where the density on the recording medium is increased by about 20%. Next, in the second line printing, the image is recognized in a state where the density is increased by about 15%, and in the second line printing, the image is recognized in a state where the density is increased by about 5%, and the desired density is obtained in the fourth line. .

FIG. 6 is a graph showing the state of FIG. 601 represents an elapsed time of 5 to 12 hours, and similarly, 6
02 represents an elapsed time of 12 to 24 hours, and 603 represents an elapsed time of 24 hours or more.

FIG. 7 is a graph showing a correction table used in the present embodiment. Here, the horizontal axis represents the input signal value,
The corrected output signal value is shown on the vertical axis. In the present embodiment, a recording apparatus capable of expressing a density of 256 gradations is used.
The recording density is determined by the value of .about.255.

Reference numeral 701 denotes a correction table in the case where no correction is performed, and the signal value conversion is performed such that “output value” = “input value”.

Reference numeral 702 denotes a correction table for obtaining a density 0.8 times that of 701 (table-through), where “output value” = “input value” × 0.8.

Reference numeral 703 denotes a correction table for obtaining a density 0.9 times that of 701 (table-through), where “output value” = “input value” × 0.9.

Reference numeral 704 denotes a correction table for obtaining a density 0.95 times that of 701 (table through), where "output value" = "input value" x 0.95.

FIGS. 8 to 11 show correction tables shown in the graph of FIG. 7 as actual signal value conversion tables. The actual signal value is expressed by 256 gradations of 8 bits. The upper 4 bits of the input signal are described in the leftmost column of the drawing, and the lower 4 bits are described in the top row of the drawing. The corrected output signal value is described in 8 bits at a location where a row and a column corresponding to each input signal are combined.

FIG. 8 shows a table-through 701, in which the input signal value and the output signal value are the same. FIG. 9 shows a correction table 702 in which the output signal value is about 0.8 times the input signal value. FIG. 10 shows a correction table 703 in which the output signal value is about 0.9 times the input signal value. FIG. 11 shows a correction table 704 in which a value 0.95 times the input signal is described as an output signal.

FIG. 12 is a flowchart showing a flow of a series of corrections performed in this embodiment.

First, in step S11, the presence or absence of a print command is checked. If there is no print command, the process returns to the start. If there is a print command, the process proceeds to S12.

In S12, the print data is input to 201 in FIG.

In the next steps S13, S14, and S15, a correction mode to be selected is determined based on the value obtained by the time measuring unit 203 in FIG. And the elapsed time is 0 hours or more 5
If the time is less than the time, the through mode of S16, the elapsed time is
If the time is equal to or longer than 12 hours, the correction mode 1 of S17,
When the elapsed time is 12 hours or more and less than 24 hours, the correction mode 2 of S18, and when the elapsed time is 24 hours or more, S19.
Correction mode 3 is selected.

Here, each correction mode will be described in detail.

<S16 Through Mode: Elapsed time 0 hours or more and less than 5 hours> Based on information from the time measurement unit 203,
When the elapsed time is 0 hours or more and less than 5 hours, the control unit 202 notifies the image processing unit of the input data to select the table through for the first line recorded by the head. The image processing unit creates output data by referring to the table through of the contents of FIG. The same processing is continued for the second and subsequent lines.

<S17 Correction mode 1: Elapsed time of 5 hours or more and less than 12 hours> According to the information from the time measurement unit 203, if the elapsed time is 5 hours or more and less than 12 hours, the control unit 2
In the case of printing the first line of the recording head with respect to the input data, 02 is transmitted to the image processing unit to select the table 704 for the input data. The image processing unit creates output data by referring to the table through of the contents of FIG. 11 from the plurality of correction tables existing in 205. In the next second line, the control unit 202 notifies the image processing unit to select the table through 701 (FIG. 8) for the input data. The image processing unit creates output data by referring to the table through of the contents of FIG. After the third line, the same processing as that for the second line is continued.

<S18 Correction Mode 2: Elapsed time of 12 hours or more and less than 24 hours> If the elapsed time is 12 hours or more and less than 24 hours according to the information from the time measurement unit 203, the control unit 202 sends the first line to the input data. Is printed, the image processing unit is instructed to select the table 703 (FIG. 10) for the input data. The image processing unit creates output data by referring to the table having the contents shown in FIG. In the next second line, the control unit 202 stores the input data in the table 704 (FIG. 1).
The image processing unit is instructed to select 1). The image processing unit creates output data by referring to the table having the contents shown in FIG. Next 3
At the line, the control unit 202 notifies the image processing unit to select the table through 701 (FIG. 8) for the input data. The image processing unit creates output data with reference to the table having the contents shown in FIG. From the fourth line onward, the processing is continued with the same table through as the third line.

<S19 Correction Mode 3: Elapsed Time 24 Hours or More> According to the information from the time measurement unit 203, if the elapsed time is 24 hours or more, the control unit 202 applies the input data to the input data in the first line printing. Table 7
02 (FIG. 9) is notified to the image processing unit. The image processing unit creates output data by referring to the table having the contents shown in FIG.
In the next second line, the control unit 202 notifies the image processing unit to select the table 703 (FIG. 10) for the input data. The image processing unit creates output data by referring to the table having the contents shown in FIG. In the next third line, the control unit 202 notifies the image processing unit to select the table 704 (FIG. 11) for the input data. The image processing unit creates output data by referring to the table having the contents shown in FIG. In the next fourth line, the control unit 202 notifies the image processing unit to select the table through 701 (FIG. 8) for the input data.
The image processing unit creates output data with reference to the table having the contents shown in FIG. From the fifth line onward, the processing is continued with the same table through as the fourth line.

As described above, when the output data is arranged according to the respective correction modes, the corrected data is transferred to the recording head in S20. Subsequently, printing is performed in S21 to complete the printing.

As described above, according to the present embodiment, by using four correction modes depending on the elapsed time,
It is possible to reduce the phenomenon that the density increases at the start of printing.

As described above, according to the present embodiment,
Even if the recording head is left for a certain period of time since the last printing and the ink density has increased, a change in the density is detected in the output image during one-pass printing without performing suction recovery or a large amount of preliminary ejection. It is possible not to let them.

(Embodiment 2) As a second embodiment of the present invention, processing during multi-pass printing will be described. Here, an example of two-pass printing will be described. The configuration of the recording device is the same as in the first embodiment.

FIG. 13 shows the state of printing scan during two-pass printing. 1301, 1302,... Each represent a print scan area by the head, where 1301 is the first scan,
1302 is the width of the area recorded by the second scan. That is, during each printing scan, a paper feed of half of the printing width is performed, and an image is completed in two consecutive printing scans in any area on the printing paper.
Also, the data actually printed in each printing scan is generally a thinned-out version of the original image by about half, and in two successive printing scans, data that are complementary to each other Have recorded.

Each line in the figure corresponds to the number of lines shown in the first embodiment, and the width of each line is determined by the number of nozzles arranged in the print head. Also in the present embodiment, if the same data is recorded, the number of recording dots included in each line area matches the number of recording dots in the first embodiment. Therefore, in the present embodiment, similar to the first embodiment, the same operation and effect can be obtained by switching the correction table every time recording of this line is completed.

Also in this embodiment, the correction is performed by the configuration shown in FIG. The control unit 202 selects a correction table for each line from 205 based on the measurement result of the time measurement unit 203 as in the first embodiment. The image processing unit performs signal value conversion on each line using the selected correction table. After the output signal value of each line is adjusted, the present embodiment further performs two-pass printing. Therefore, the number of data is reduced according to a predetermined thinning method, and the result is transferred to the print head 206.

Hereinafter, a portion related to the correction mode will be described.

<Through mode: elapsed time 0 hours or more 5
If the elapsed time is from 0 hours to less than 5 hours based on the information from the time less than the time measuring unit 203, the control unit 202 informs the image processing unit to select the table through for the first line area for the input data. . The image processing unit 205
The output data is created by referring to the table through having the contents shown in FIG. The same processing is continued in the subsequent second line area and thereafter.

<Correction mode 1: Elapsed time 5 hours or more 1
If the elapsed time is 5 hours or more and less than 12 hours according to the information from the time measurement unit 203, the control unit 202 determines that the input data is in a table 704 (FIG. 11) in the first line area. To the image processing unit to select. The image processing unit creates output data by referring to the table through of the contents of FIG. 11 from the plurality of correction tables existing in 205. In the area of the next second line, the control unit 202 notifies the image processing unit to select the table through 701 (FIG. 8) for the input data.
The image processing unit creates output data by referring to the table through of the contents of FIG. After the third line area, the same processing as that for the second line is continued. In the correction mode 1 by the above control, the correction conversion by the table 704 is performed for the line 1 and the table through 701 is performed for the line 2 and thereafter.

As a result of performing the above control in two passes, the recording operation of the head is as follows. First, in the printing scan 1301 in which only the first line area is formed, 7
04 is applied. In 1302, the correction of 704 is applied to the upper half nozzle area, and the lower half area is 701 table through. Subsequent steps 1303 and thereafter are converted by table through 701 in all areas.

<Correction mode 2: Elapsed time 12 hours or more and less than 24 hours> According to information from the time measurement unit 203, if the elapsed time is 12 hours or more and less than 24 hours, the table 703 ( (FIG. 10)
However, in the second line area, the table 704 (FIG. 11)
In the third line area, the table through 701 (FIG. 8)
After the fourth line area, the same table through 701 as that of the third line is selected.

As a result of performing the above control in two passes, the recording operation of the head is as follows. First, in the printing scan 1301 in which only the first line area is formed, 7
03 correction has been applied. In 1302, the correction of 703 is applied to the area of the upper half nozzle, and the correction of 702 is applied to the area of the lower half. Continue 13
03 is subjected to 702 correction in all areas. 1
In 304, the upper half has been corrected by 702, and the lower half has 701 table through. All the areas after 1305 are converted by 701 table through.

<Correction mode 3: Elapsed time 24 hours or more> According to the information from the time measurement unit 203, if the elapsed time is 24 hours or more, the table 702 (FIG. 9) for the input data in the area of the first line is The table 703 (FIG. 10) in the second line area, the table 704 (FIG. 11) in the third line area, the table through 701 (FIG. 8) in the fourth line area, and the fourth line after the fifth line area Table through 701 is selected.

As a result of recording the above control in two passes, the recording operation of the head is as follows. First, in the printing scan 1301 in which only the first line area is formed, 7
02 correction is applied. In 1302, the area of the upper half nozzle is corrected by 702, and the area of the lower half is corrected by 703. Continue 13
03 is subjected to 703 correction in all areas. 1
In 304, the upper half is corrected by 703, and the lower half is corrected by 704.
At 1305, the correction of 704 is applied to all the areas. In 1306, the upper half is corrected by 704, and the lower half is subjected to 701 table-through. In the subsequent print scan, all areas are converted by 701 table-through.

As described above, even in two-pass printing, 1
By using the same table data for the image data forming the same line as at the time of the pass, it is possible to cope with this.

Further, a plurality of passes (4 passes, 8 passes...)
In the same manner, it is possible to cope with printing by using the same table data for the image data forming the same line.

The most basic feature of the present invention resides in that "the state where the density is high immediately after the start of printing" is corrected by converting the signal value of the input data. As described above, it is known that the above problem is gradually solved as the thickened ink is consumed by some method such as suction recovery, preliminary ejection, or actual printing. That is, originally, a signal location conversion such as using a correction table according to the consumed ink amount is the most effective method of the present invention. In the above embodiments, the method of switching the correction table according to the number of recorded lines has been disclosed, but the present invention is not limited to this. As an indicator of the amount of ink consumed other than the number of lines, for example, the number of ejection dots, the number of printing scans, and the like are given. If the correction table is switched according to a predetermined threshold using these parameters, the effect of the present invention should be obtained more than in the above embodiment. In the above-described embodiment, the method of switching the table for each fixed line region is adopted in consideration of the simplicity and cost of data processing, the processing time, and the like, for ease of implementation.

In each embodiment, the correction table 702 is used.
Although the description has been made on the assumption that the correction is made in three steps of 0.8 to 0.95 as ７０ to 704, the present embodiment and the present invention are not limited to this. Each table may be set at a finer stage, and may not have the same proportional distribution for all input values. In other words, the present invention is also effective for a non-linear correction table in which the correction ratio from the through signal differs depending on the input signal.

In the above embodiment, the correction method for one color has been mainly described. However, each embodiment can also cope with color ink jet recording in which a plurality of color inks are mounted as described with reference to FIG. is there. In that case, the correction table and the time division (threshold) may be independent for each color.

Further, although not described in the above description,
Actually, the evaporation state of water in the nozzle and the increase in viscosity and dye concentration are greatly affected by the surrounding environmental temperature and humidity. That is, even if the same 5 hours are left, the ink concentration does not increase so much in a high humidity environment, but when the device is placed in a low humidity environment, the ink viscosity and The dye concentration near the discharge port increases. In this case, it is more accurate to provide a hygrometer, a thermometer, and the like, and to independently provide the correction mode according to each environment, instead of uniquely determining the correction mode based on the leaving time as described above. Density correction can be performed.

[0063]

As described above, according to the present invention, for example, a correction table corresponding to the elapsed time indicating the non-recording time is used,
The density signal is corrected so that its value becomes smaller, and based on the corrected density signal, at least a predetermined amount of recording at the start of recording is performed. Even when printing is performed with the ink thus formed, the density of the above-described predetermined amount of printing can be reduced overall, and can be made substantially equal to the density printed with the ink having the normal density.

As a result, it is possible to record a uniform image without a change in density without performing a large amount of suction or preliminary ejection.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an ink jet recording apparatus used in an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration for performing signal value processing in the embodiment of the present invention.

FIG. 3 is a diagram illustrating a phenomenon in which the density at the start of printing increases.

FIG. 4 is a graph showing elapsed time and a density change rate.

FIG. 5 is a table showing an elapsed time and a density change rate in the number of print lines.

FIG. 6 is a diagram showing a density graph of FIG. 5;

FIG. 7 is a diagram in which a correction table is graphed.

FIG. 8 is a diagram of a correction table (output value = input value).

FIG. 9 is a diagram of a correction table (output value = input value × 0.8).

FIG. 10 is a correction table (output value = input value × 0.85)
FIG.

FIG. 11 is a correction table (output value = input value × 0.95)
FIG.

FIG. 12 is a diagram illustrating a processing flow according to the embodiment of the present invention.

FIG. 13 is a diagram illustrating two-pass printing.

[Explanation of symbols]

Reference Signs List 101 inkjet head 102 recovery processing unit 103 belt 104 paper feed roller 105 paper feed roller 106 recording paper 201 image data input unit 202 control unit 203 time measurement unit 204 image processing unit 205 correction table 206 recording head 601 elapsed time 5 to 12 hours Density curve for number of recording lines 602 Density curve for number of recording lines with elapsed time of 12 to 24 hours 603 Density curve for number of recording lines with elapsed time of 24 hours or more 701 Table-through correction curve 702 0.8-times correction curve 703 0. 85 times correction curve 704 0.95 times correction curve 1301 2-pass printing, print area in first print scan 1302 2-pass print, print area in second print scan

Claims (12)

[Claims] 1. An ink jet printing apparatus for printing using a print head having a plurality of nozzles for ejecting ink droplets, comprising: a time measuring means for measuring an elapsed time from the previous printing to the start of printing; A plurality of density correction tables for converting to a value lower than the density value indicated by the density signal; and one of the plurality of correction tables according to the elapsed time.
Selecting means for selecting one, and control means for performing recording at least a predetermined amount to be recorded at the start of the recording based on the density signal corrected using the correction table selected by the selecting means. Characteristic inkjet recording device. 2. The apparatus according to claim 1, wherein the selection unit sequentially switches and selects one of the plurality of correction tables according to the elapsed time and a recording amount from a recording start time. Ink jet recording device. 3. The ink jet recording according to claim 2, wherein the recording amount is the number of line areas recorded in a single scan of the recording head, recorded from the start of recording. apparatus. 4. The ink jet recording apparatus according to claim 2, wherein the recording amount is the number of scans of the recording head recorded from the start of recording. 5. The ink-jet recording apparatus according to claim 2, wherein the recording amount is the number of ejections of ink droplets of the recording head from the start of recording. 6. The ink jet recording apparatus according to claim 1, wherein the plurality of recording heads corresponding to a plurality of ink colors are used, and the plurality of correction tables are provided for each of the plurality of recording heads. 6. The ink jet recording apparatus according to any one of 1 to 5. 7. The apparatus according to claim 1, wherein the density correction table is provided for each of the plurality of nozzles.
3. The ink jet recording apparatus according to claim 1. 8. An ink jet recording method for performing recording using a recording head in which a plurality of nozzles for ejecting ink droplets are arranged, wherein a plurality of density corrections for converting a density signal into a value lower than a density value indicated by the density signal. A table is prepared, the elapsed time from the previous recording to the start of recording is measured, and one of the plurality of correction tables is determined according to the elapsed time.
An ink jet recording method comprising the steps of: selecting at least a predetermined amount to be recorded at the start of the recording based on the density signal corrected by using the correction table selected by the selection. . 9. The method according to claim 8, wherein in the selecting step, one of the plurality of correction tables is sequentially switched and selected in accordance with the elapsed time and a recording amount from a recording start time. Inkjet recording method. 10. The inkjet recording according to claim 9, wherein the recording amount is the number of line areas recorded in a single scan of the recording head and recorded from the start of recording. Method. 11. The ink jet recording method according to claim 9, wherein the recording amount is the number of scans of the recording head recorded from the start of recording. 12. The ink jet recording method according to claim 9, wherein the recording amount is the number of ejections of ink droplets of the recording head from the start of recording.