JP2001246742A - Method of resolution changeable ink-jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clearly and surely form an image of very small ink drops with a substantially high resolutions by eliminating factors for the quality and color of the image when the resolution is changed. SOLUTION: A driving condition and binary data for driving so that ink drop (an ink volume by the number of drops) of a range not exceeding a maximum quantity of ink to be hit per unit area of a recording medium can be discharged are formed in accordance with the resolution, a recording condition including the recording medium and an environmental condition.

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 for forming characters and images by depositing ink droplets on a recording medium, and more particularly to an ink jet recording head having an m (> n) resolution using an n-resolution ink jet recording head. The present invention relates to an inkjet recording method capable of performing recording, which is suitable for high-resolution recording or high-gradation recording.

The present invention relates to ordinary paper, special paper, cloth, OHP
The present invention can be applied to all devices using a recording medium such as paper.
Specific examples of applicable devices include a printer, a copying machine, a facsimile, and the like.

[0003]

2. Description of the Related Art Ink jet recording has low noise, low running cost, easy downsizing of apparatus, easy colorization,
There are advantages such as. Color ink jet recording uses three color inks of cyan (C), magenta (M), and yellow (Y), or black (B)
This is performed using four colors of ink to which k) is added. Some color recordings are performed using inks such as green (G), red (R), and blue (B).

In the conventional ink jet recording, in order to obtain an image without ink bleeding, it was necessary to use a special paper having an ink absorbing layer. In recent years, a method has been put to practical use that has been given a printing suitability for “plain paper” used in large quantities in printers, copiers, and the like due to improvements in ink.

However, at present, high-definition recording quality on "plain paper" is still at an insufficient level. The cause is largely due to bleeding of the ink adhered to the recording medium. Comparing the case of recording on special paper and the case of recording on plain paper with ink droplets of the same volume designed to reduce ink bleeding, the bleeding on plain paper is naturally worse than that of specialty paper. And the outline of the recorded area becomes ambiguous. In this way, high-resolution recording on plain paper is more disadvantageous than dedicated paper,
It is known that recording on plain paper can improve image quality by recording with a smaller volume of ink droplets.

On the other hand, there are many known techniques relating to smoothing processing as a pseudo method for increasing the resolution. For example, U.S. Pat. No. 4,809,021 describes that smoothing printing is performed using three or more types of dots.
This is a technique for smoothly recording characters, for example, using dots of various sizes. In this method, preparations for constantly recording dots of various sizes are required. For example, a recording head having various types of nozzle diameters and a part for converting an image to be recorded into data corresponding to each nozzle diameter are required.

There are also many proposals on edge enhancement as a method of improving image quality. For example, Japanese Patent Application Laid-Open No. 1-21
Japanese Patent Application Laid-Open No. 2176 discloses that an image signal is secondarily differentiated, a signal of an original image is calculated as smoothed data, and an edge portion is emphasized. This is a proposal for edge enhancement with constant resolution. There are many other proposals related to edge enhancement, and there are many known means.

Japanese Patent Laid-Open Publication No. Sho 55-132259 discloses a method in which a plurality of heating elements for discharging ink are provided for each orifice of an ink jet head, and gradation recording is performed by changing the size of discharged ink droplets. How to do it is described.

As described above, in the conventional ink jet recording, various proposals have been made to improve the recording quality of an image.

[0010]

However, using a conventional n-resolution inkjet recording head, m (>
n) In an ink jet recording method and apparatus capable of recording at a resolution, if the data is simply converted by converting the data according to the resolution and then recorded, the quality and color of the image formed on the recording medium changes, and the recording is satisfactory. Couldn't get the picture going.

[0011] The present inventors have pursued a cause of the change in resolution that affects the quality and color of an image. Originally,
It was clarified that various factors that did not significantly affect the image when performing the n-resolution inkjet recording substantially disturb the image formed by the small ink droplets for the high resolution.

Specifically, the setting is made at n resolutions.
There is a problem that the upper limit of the maximum ink ejection amount per unit area of the recording medium is exceeded with the conversion data of m resolution. In a print mode for forming a color image or performing high-quality recording, there is a problem that the image quality is particularly deteriorated. The environmental conditions such as the temperature change information of the recording head determined in the predetermined subroutine or the environmental temperature and humidity change information where the apparatus is placed are not appropriately considered at the time of resolution conversion, and the image is used as a fluctuation factor. There were some upset issues. The recording conditions such as the use of the fixing device, the moisture absorption state of the recording medium, the ink characteristics, the ink absorption characteristics of the recording medium, and the characteristics of the recording medium such as the material are not properly considered at the time of resolution conversion, and the image is disturbed as a variable factor. Problems can be mentioned. Further, in a mode for correcting the initial setting conditions such as a test print in a recording apparatus, n
One of the causes is that the setting is only made at the resolution, and the conversion recording at the m resolution is not optimized. In some cases, it is not possible to optimize the ink droplet itself because the head surface cleaning, preliminary ejection, suction recovery, or pressure recovery that stabilizes the recording head is not properly performed during resolution conversion. .

Accordingly, the present invention provides a data variation factor when changing the resolution, a variation factor of an ink droplet amount from a recording head such as an environmental condition, a variation factor of an ink droplet image on a recording medium such as a printing mode and recording conditions, or the like. The object of the present invention is to solve the problem of the related art by optimizing at least one of the setting of the initial condition of the apparatus and the optimization of the stabilizing means of the recording head at the time of resolution conversion.

In particular, in consideration of any of these, it is necessary to set a driving condition under which ink droplets (ink volume × number) can be ejected within a range not exceeding the maximum ink ejection amount per unit area of the recording medium. It is possible to provide an ink jet recording method and a recording apparatus capable of performing high-quality recording in accordance with characteristics of a recording medium regardless of input image data or recording conditions.

In any case, an object of the present invention is to provide an ink jet recording method and a recording apparatus capable of performing high resolution ink jet recording with high quality.

[0016]

According to the present invention, m (> n) is applied to a recording medium by using an n-resolution ink jet recording head.
In an inkjet recording method for recording a resolution,
setting a low-resolution recording mode for recording at n-resolution and a high-resolution recording mode for recording at m-resolution;
When the set print mode is the high-resolution print mode, the step of converting the density level of the multi-value data to be printed so as to lower the density level is appropriately performed by the inkjet printing method. Can be.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view of an ink jet recording apparatus as an embodiment to which the present invention can be applied. Recording medium 1 inserted at a paper feed position of recording apparatus 100
Reference numeral 06 is conveyed to a recordable area of the recording head unit 103 by the feed roller 109. A metal platen 108 is provided below the recording medium in the recordable area. The carriage 101 has two guide shafts 104
And 105 are movable in the direction determined by the scanning direction, and reciprocally scans the recording area. Carriage 101
Is mounted with a recording head unit 103 including an ink tank for supplying four color inks and a recording head for discharging those inks. The four color inks provided in the ink jet recording apparatus of this embodiment are black (B
k), cyan (C), magenta (M), yellow (Y)
It is. Reference numeral 107 denotes a switch unit and a display element unit for displaying various recording mode settings and the status of the recording apparatus.

FIG. 2 is a perspective view of the recording head unit 103. A black ink tank 21 for storing black ink and a color ink tank 20 for integrally storing the other three color inks are connected to a print head 102 by pipes, respectively. Supplied to The discharge port surface 22 has B
A plurality of discharge ports 23 corresponding to each color of k, C, M, and Y are linear. The number of ejection ports for each color is 32. The pitch between the 32 orifices of each color is about 70μ.
They are arranged linearly at a density of 360 dpi, which is m.
In addition, the ejection ports between the colors are arranged with an interval of 8 dot pitch. The ejection openings for each color are Bk, C,
They are arranged so as to be recorded in the order of M and Y.

In the ink jet recording apparatus according to the present embodiment, an electric / heat converter is arranged corresponding to a liquid path (nozzle) of ink, and a drive signal corresponding to recording information is applied to the electric / heat converter to make a nozzle. This adopts a recording method in which ink is ejected from the printer.

FIG. 3 is an enlarged sectional view of the vicinity of the electric / heat converter of the recording head.

The heating element 30, which is an electric / heat conversion element of the recording head, is provided with a heating element 30 capable of generating heat independently for all nozzles.

The ink in the nozzle, which is rapidly heated by the heat generated by the heating element 30, forms bubbles due to film boiling, and the ink droplets 35 are ejected toward the recording medium 31 as shown in FIG. Then, characters and images are formed on the recording medium. At this time, the volume of each color ink droplet to be ejected is 40 to 60 ng.

Each of the discharge ports 23 is provided with an ink liquid path communicating with the discharge port, and a common liquid for supplying ink to these liquid paths is provided behind the portion where the ink liquid path is provided. A chamber 32 is provided. In the ink liquid passage corresponding to each of the discharge ports, there is provided a heating element 30 which is an electric-to-heat converter for generating thermal energy used for discharging ink droplets from these discharge ports, and for supplying power thereto. Are provided. These heating element 30 and electrode wiring
It is formed on a substrate 33 made of silicon or the like by a film forming technique. A protective film 36 is formed on the heating element 30 so that the ink does not directly contact the heating element. Further, the discharge port, the ink liquid path, the common liquid chamber, and the like are formed by laminating the partition wall 34 made of a resin or a glass material on the substrate.

As described above, the recording method using the electric / heat converter uses a bubble formed by applying thermal energy when ejecting ink droplets, and is therefore generally called a bubble jet (registered trademark) recording method. ing.

FIG. 4 is a block diagram of an ink jet recording apparatus to which the present invention can be applied. Character or image data to be recorded (hereinafter, referred to as image data) is input from the host computer to the reception buffer 401 of the recording device. Further, data for confirming whether data is correctly transferred and data for notifying the operation state of the recording apparatus are returned from the recording apparatus to the host computer. The data in the reception buffer 401 is transferred to the memory unit 403 under the control of the CPU 402 and temporarily stored in a RAM (random access memory). Mechanical control unit 404
Drives a mechanical unit 405 such as a carriage motor or a line feed motor according to a command from the CPU 402. The sensor / SW control unit 406 includes various sensors and SWs.
A signal from a sensor / SW unit 407 including a (switch) is sent to the CPU 402. Display element control unit 408
Controls display elements such as LEDs of the display panel group in accordance with a command from the CPU. Recording head control unit 410
Controls the recording head 411 according to a command from the CPU. Further, temperature information indicating the state of the recording head 411 is sensed and transmitted to the CPU 402.

FIG. 5 is a flowchart of the first embodiment for processing print data.

STEP 11 is the CPU 402 of the recording apparatus.
This is the step in which the input data is sent to. The input data is data sent from the receiving buffer, data sent from the sensor / SW control unit, and data sent from the recording head control unit.

STEP 12 is a step of taking in image data (hereinafter referred to as data 1) which is a part of the input data sent from the reception buffer. When the density is adjusted by the user in the host computer or the SW unit of the printing apparatus, the image data is density-adjusted image data. Here, the case where the image data is multi-valued data is shown.

STEP 13 is a control data determining means 20.
2 is shown. Media data, mode data, and environmental data (hereinafter, data 2) that are part of the input data
3 shows the step of incorporation. Here, the medium data indicates whether the recording medium is dedicated coated paper, plain paper, transparency paper, or other.
Setting data sent from the host computer, or
This refers to data set by a sensor / SW unit in the printing apparatus. The mode data is data indicating whether the mode is the high-speed recording mode or the high-quality recording mode. Environmental data refers to data indicating environmental conditions such as the temperature of a printhead, the temperature of ink to be printed, and the temperature and humidity in a printing apparatus. The control data of the printing apparatus is determined from these data.

STEP 14 shows the steps in the maximum ink ejection rate determining means 203. From the data 2, the maximum ink ejection rate N is determined. When the usable recording medium is specified in advance, that is, when it is assumed that a special recording medium with high ink absorbency is used so that an ink droplet image for high resolution can be formed, the maximum ink ejection is performed. The reference of the rate N may be obtained by correcting the reference driving rate N stored in advance in the apparatus in accordance with the above environmental conditions and the like.

Here, a specific example will be described. "Maximum allowable ink absorption per unit area: IMax" of the recording medium
Is determined by the data 2, the maximum ink ejection rate N is determined from IMax.

Since the recording conditions serving as a reference are based on the characteristics of the ink to be used, as an example, glycerin 5.0% by weight thiodiglycol 5.0% by weight urea 5.0% by weight isopropyl alcohol 4.0% by weight Acetyleneol EH 0.5% by weight Dye 3.0% by weight Water 77.5% by weight (a dye is a dye corresponding to each of Y, M, C and Bk). Further, the conditions were as follows: dedicated coated paper, high image quality mode, temperature 25 ° C., humidity 60% RH, and head temperature 35 ° C. At this time, IMax
Was about 20 μg per square mm. This is 3
When converted to unit area in units of 60 dpi angle,
It is about 100 ng. In this manner, a relative change can be expressed by setting a certain reference for the print medium to be used and the print conditions and defining the maximum ink ejection rate N with respect to this reference. In this example, the above value of 10
The ratio was 0 ng. For example, IMax is 60ng
Under the recording condition of, N = 0.6.

The determination of IMax is performed as follows. Actually, a boundary of different colors of ink to be used is formed in a relatively large area of the recording medium, and a reference is given to the degree of the bleeding at this boundary. . In this example, a single color (Y, M, C) ink is used and the ink mixed color (R, M, C) is used.
G, B) and Bk (black) in various colors 1i
The limit value is defined as the limit value when the amount of ink recorded so as to fill the nch square surface exceeds a certain value (for example, 2 in minimum recording pixel units) between different adjacent colors. In other cases, the fixing characteristics may be determined immediately after recording.

In STEP 15, the maximum ink ejection rate N
Is a process of changing the multi-value level of the image data of the data 1 based on. The output data Dout after the change is obtained by using the conversion function Func with the input data Din and N as parameters.
And Dout = Func (N, Din).

FIG. 6 is a diagram showing a specific image data conversion process according to the first embodiment. 8-bit 2 with general gamma conversion
The input data Din of 56 gradations is also converted into output data Dout of 256 gradations of 8 bits. This example is a case where the recording paper is a specific plain paper based on the above-described reference recording conditions, and a case where N = 0.8. The volume of one ink droplet to be ejected is controlled to be constant at 50 ng.
In the case of color recording, secondary colors R, G, and B are represented by overlapping Y, M, and C, so that a total of 100 ng is recorded in a unit area of 360 dpi angle.
In the case of N = 1, this may be left as it is, but in the case of N = 0.8, it is too large. Therefore, the following conversion processing is performed to reduce the average ink ejection amount per unit area.

The conversion function is a function that becomes a straight line b obtained by translating a straight line a in which input data and output data are a one-to-one conversion function so that the maximum value of input data becomes 0.8 times in output data. And This conversion function has an advantage that the offset processing for cutting the input value is applied, particularly in a region where Din is small, and the granularity of the highlight recording unit is reduced. Here, when N is greater than 1, the input data is not converted, and Dout = Din.

This conversion process is a process for optimizing the amount of ink droplets to be recorded on the recording medium. The ejection amount of the ink droplet is the volume of the ink droplet per dot ejected toward the recording medium, the number of the ink droplets, or both. Here, the control is such that the volume of the ink droplet is always constant. Therefore, the number of ink droplets per unit area was optimized. Alternatively, 1
The volume or the volume and number of ink droplets per dot may be variably controlled.

In this example, the control is such that the volume of the ink droplet is always constant. When N is greater than 1, the input data is not converted and Dout = Din.
Is larger than 1, control is performed to increase the volume of the ink droplet correspondingly, whereby a wider range of effects can be obtained. As a specific means for increasing the volume of the ink droplet, the energy applied to the heating element of the recording head at the time of discharging the ink is increased, or the temperature of the discharged ink is increased to lower the viscosity.

Further, the conversion function for converting the multi-value level of the image data may be a conversion obtained by multiplying the input data Din by N as shown by a straight line c instead of the straight line b in FIG. Alternatively, it may be a function that is not linear.

STEP 16 is a step of binarizing the multi-value data. Here, a known error diffusion method was used.

STEP 17 is a step of fixing the binarized image data and converting it into print data for driving the print head of the printing apparatus.

The recording data processed according to the above flow is
The print data is sent to the print head controller unit 410, and print data is printed by the print head 411.

(Second Embodiment) In the first embodiment, the case where the input image data is multi-value data has been described. The present invention is not limited to this, and the present embodiment describes a case where input recording data is binary data.

FIG. 7 is a flowchart for processing print data according to the present embodiment.

STEP 21 is the CPU 402 of the recording apparatus.
Shows a process in which the input data is sent. STEP22,
Similar to STEP 12, a step of capturing data 1 as image data from input data is shown. However, the input image data is binary data.

STEP23 performs the same processing as STEP13, and STEP24 performs the same processing as STEP14.

In STEP 25, a process of converting binary data into multi-value data is performed. STEP26 is the same process as STEP15, STEP27 is the same process as STEP16, and STEP28 is the same process as STEP17.

Thus, even when the input image data is binary data, the data processing step of the present invention is effective.

Here, the portion indicated by the dashed line indicated by the processing 1 in FIG. 7 may be a processing method different from the above processing. For example, a pattern processing method may be used in which the minimum unit of a recording pixel is 1, and 16 × 16 mask data created or selected based on N is processed with image data.

(Embodiment 3) Embodiments 1 and 2 show the case where the input image data is multi-value data or binary data. In this embodiment, a case where data in which multi-value data and binary data are mixed is input will be described.

FIG. 8 is a flowchart for processing image data when multi-value data and binary data are mixed.

In STEP 31, the CPU 402 of the recording apparatus is used.
Shows a process in which the input data is sent. STEP32,
5 shows a process of capturing image data as data 1. However, what is input is data in which binary data and multi-value data are mixed.

STEP 33 performs the same processing as in STEP 13, and STEP 34 performs the same processing as in STEP 14.

STEP 35 is a process for determining whether the data is multi-valued or binary. In the case of multi-value, the binary data is converted into multi-value data in STEP 36 in the case of binary.

STEP 37 is the same processing as in STEP 15, STEP 38 is the same processing as in STEP 16,
P39 is the same processing as STEP17.

As described above, the data processing step of the present invention is effective even when the input image data is data in which binary and multi-level data are mixed.

Here, the processing 2 indicated by a broken line including the area indicated by the multi-value processing in FIG. 8 may be different from the above processing method. For example, for binary data, a pattern processing method may be used in which the minimum unit of a recording pixel is 1, and 16 × 16 mask data created or selected based on N is processed with image data.

Fourth Embodiment In the first embodiment, it is not distinguished whether the input image data is black (Bk) or color (Col = Y or M or C). There is a good effect that can be obtained by distinguishing between black and color. Since the color is obtained by superimposing and recording YMC to record RGB, the ink ejection amount to the recording medium is Bk.
More. Conversely, more Bk can be discharged. In the present embodiment, it is determined whether the input image data is black or color.

FIG. 9 is a flowchart for processing the data to be optimally recorded by distinguishing whether the image data is black or color.

STEP 41 is the CPU 402 of the recording apparatus.
Shows a process in which the input data is sent. STEP42,
5 shows a process of capturing image data as data 1. However, the image data is data in which black and color data are mixed.

In step 43, the same processing as in step 13 is performed. STEP44 is a process similar to STEP14,
Maximum driving rate N1 for black and color independently
And N2 are determined. Here, the black ink ejection amount and the color ink ejection amount are made equal to 50 ng each.
Therefore, N1 = 2 × N2.

At STEP 45, the image data is multivalued. At STEP 46, a judgment is made as to whether the image data which is multi-valued data is black or color. S for black
The process goes to STEP 47, or to STEP 48 for color. More preferably, the colors Bk, C, M, and Y are determined, and the following processing is performed separately. Here, the processing is performed to determine two types, black and color.

STEP 47 is a process similar to STEP 15 for changing the black multi-value level of the image data of data 1 based on the maximum ejection ratio N1.
Similarly, STEP 48 is a process of changing the multi-value level of the color of the image data of data 1 based on the maximum ejection rate N2. After the processing for changing the multi-value level independently of each other, the process goes to STEP49.

STEP 49 is a process similar to STEP 16, and STEP 50 is a process similar to STEP 17.

Here, the ink ejection amounts of black and color may be different. In general, in a recording system that emphasizes black, the amount of black ink discharged is increased. In this case, the same processing is performed.

Further, the determination for distinguishing black from color may be made not on Bk and C or M or Y, but on a region containing Bk in Bk and C or M or Y. this is,
For example, black in an area where a natural image such as a photograph is recorded is determined to be included in color, and is suitable for recording a natural image.

Here, the processing of the portion surrounded by the broken line shown in processing 3 in FIG. 9 may include a step of determining whether the image data is black or color, and may be processed by the pattern matching method. Good.

(Embodiment 5) In this embodiment, in addition to the first embodiment, the processing of the edge part of the image data is different from the processing of the part other than the edge part, whereby a good effect is obtained. .

FIG. 10 is a flowchart for performing different processing for the edge portion of image data and other portions.

STEP 51 is a step in which input data is sent to the CPU 402 of the printing apparatus, as in STEP 11. STEP 52 shows a step of taking in the image data which is the data 1. STEP53 performs the same processing as STEP13. In STEP54, N is determined by the same processing as in STEP14.

STEP 55 is a step showing a multi-value processing. STEP56 is to determine whether the image data is an edge portion.
This is a step of making a determination in units of minimum pixels. If it is an edge part (yes), go to STEP 57; if different (no),
Go to STEP58.

In this step 56, "whether or not an edge portion" is determined. In addition, "the input level is the maximum or near the maximum" is added to the condition. It is good also as going processing. This is because it may be better to determine that all the data expressing the halftone at the multi-value level is not an edge portion. For example, the density of a black recording pixel in an area expressing gray may be increased if the processing is performed such that the edge portion is recorded with emphasis. If the multi-value level “input level is maximum” is determined, there is no such problem of high density because the halftone level is not the maximum. In addition, the "input level near the maximum"
For example, if 250 levels or more are targeted at 256 gradations, there is no problem of relatively high density.

At STEP 58, a process of changing the multi-value level of a portion other than the edge portion of the recording data is performed. This is a process similar to STEP15.

At STEP 57, a process for changing the multilevel level of the edge portion of the recording data is performed. This process is called STE
Processing different from P15 is performed. Generally, the determination of the maximum ink absorption amount of a recording medium is determined by an image in which a relatively large recording area is filled. This is because the most severe condition is an image in which a relatively large recording area is filled. However, since the ink easily penetrates from the recording area to the non-recording area at the edge portion, the condition is somewhat relaxed. Therefore, the edge portion may change the multilevel level with a value larger than N. For example, it is set to 1.1 times N. Alternatively, it is assumed that the edge portion does not perform the multilevel level change processing. These detailed settings are determined by the ink to be used, the recording medium, and other conditions. In any case, the processing is performed so as to discharge more ink than the non-edge portion. It is generally known that the ink discharge amount at the edge portion may be larger than that at the non-edge portion, and that when printing characters and images, the higher the edge portion, the better the quality. Because it is. Also, the edge portion discharges as many ink drops as possible to increase the density of the recorded image. A region where a relatively large region other than an edge portion is recorded at a high recording density is often not reflected on a recorded image even if the resolution is increased, so it is meaningful to perform recording with priority on density.

At STEP 59, the image data separately processed at the edge portion and the other portions are subjected to a compound process to perform a binarization process. STEP60 is the same as STEP17.

Here, the processing of the portion surrounded by the broken line shown in processing 4 in FIG. 10 may include a step of judging whether or not it is an edge of the image data and separately processing it. May be processed.

The determination as to whether or not an edge is made may be made by known means. In general, an edge portion is defined as an edge portion in the unit of the minimum recording resolution of a recorded image. Here, depending on the recording conditions, not only the outermost part but also, for example, a two-pixel area in which the outermost part and the further inner part are combined may be used. Alternatively, depending on the recording conditions, 10
It may be a shell of about a layer. This is, for example, STEP
If the error diffusion method is used in the binarization process of No. 59, the error data component diffused in the processing of a natural image such as a photograph overlaps with the character written on the natural image, and the character is blurred. There is an advantage that can be reduced.

Further, the edge portions are Bk, Y, M,
C, instead of the edge part for each color, it may be the edge part of the logical OR data of each color. This is because the border of each color is
This is because each color is an edge but is not an edge as a recording area.

FIG. 11 shows an example in which the boundary between black and yellow is processed according to the flow of FIG. Black circles indicate black and white circles indicate yellow.

The input image data corresponds to a case where black and yellow are adjacent to each other at 24 × 32 pixels at the minimum recording resolution. Eight pixels at the edge of the logical OR data of black data and yellow data remain the same,
This shows a case where the data has been subjected to a / 2 conversion process.

Embodiment 6 Embodiment 6 of the present invention will be described.

FIG. 12 is a flowchart for explaining this embodiment. The image data to be recorded is a full-color image,
Processing steps when image data including various types of object image data are input will be described. Various types of object image data include character data, natural image (full color) data, graph (7 color) data,
This is binary data, multi-value data, or the like. The resolution of the input image data is 360 dpi and the image size is A
4. The description will be made assuming that the gradation level is image data of 8 bits for each color.

In STEP 61, the input data sent from the host computer is converted into data 1 as image data.
And the process of separating the data into control data 2 and sending the data to the respective steps 62 and 63.

In STEP 62, the image data is divided into header information (image resolution, image size, data depth indicating whether the number of gradations is 2 bits or 8 bits, object information, etc.) and image data, and pattern processing is performed. Send to the department.

STEP 63 shows the processing steps in the control data determining means. The number of print passes during the printing operation determined by the printing medium data, mode data, and environmental data, the mask pattern, the driving conditions of the printing head, whether the printing is unidirectional or reciprocal, and the amount of intermittent feeding of the printing medium during the printing operation. The control information is sent to the pattern processing unit. Here, a case will be described in which the recording medium is a dedicated coated paper, the number of recording passes is two, and bidirectional printing is performed.

STEP 64 shows the processing steps in the maximum ink ejection rate determining means 203. From the recording medium data, the mode data, and the environment data, the maximum ink ejection rates N1 and N2 for black and color (C, M, Y) are determined. Here, N1 = 0.9, N2
= 0.8.

Next, processing is performed in a pattern processing unit surrounded by a dotted line so that an optimum recording image is obtained from the respective conditions of data 1 and data 2.

Step 65 is a multi-value processing step. Since the image data is multi-value data here, the process directly proceeds to the next step.

At STEP 66, it is determined whether the image data is black or color. S when the image data is black
Go to STEP 67, and if it is color, go to STEP 68.

STEP 67 and STEP 68 are steps for determining whether or not the image data is an edge portion.

In STEP 67, an edge detection process of a known second-order differentiation process is performed. In STEP 68, an edge detection process of a well-known first-order differentiation process was performed. STEP67
The difference between the edge detection process in STEP 68 and that in STEP 68 is that black data is often used for character data that is data for reading, and that inking (UC
This is because it is preferable to increase the edge detection accuracy because it is used as R). On the other hand, color data has many images for viewing a recorded image, such as a natural image such as a graph or a photograph, and it is preferable to perform smooth processing compared to black. As another method, STEP67 and STEP68 may be the same edge detection processing method in order to simplify the processing steps.

STEP 69 is a process for processing black image data determined to be an edge portion. Processing 6 is performed based on the maximum black ink ejection ratio N1 determined in STEP64. As an example of the process 6, only the outermost pixels of the edge portion are recorded by a known smoothing process at a resolution of 720 dpi which is twice the resolution of the original image. Further, the data is converted into data for recording a maximum of four ink droplets into a minimum recording pixel at a resolution of 360 dpi.
At this time, the resolution of the ink ejection port of the recording head is 360d.
The recording head scans the recording area twice for recording at a resolution of 720 dpi because of the pitch.

FIG. 13 is a diagram showing scanning of the recording head according to the sixth embodiment. FIG. 9 is a diagram illustrating the number of scans (scans) of a print head and a print area for realizing printing at a resolution of 720 dpi with a print head having a resolution of 360 dpi.

STEP 70 shows a process for processing black image data which is not an edge portion. The image data is converted according to the function of the maximum black ink ejection ratio N1 determined in STEP64. In the conversion processing, the input data before the conversion processing is Din, the output data after the conversion processing is Dout, and the conversion function is func, and the calculation processing is defined as follows.

Dout = f (N1, Din) = DinxN1 STEP 71 shows a process of processing color image data determined to be an edge portion. Processing 7 is performed based on the maximum ink ejection rate N2 of the color. As an example of the process 7, only the outermost pixel of the edge portion is recorded by a known smoothing process at a resolution of 720 dpi which is twice the resolution of the original image. Further, the data is converted into data for recording a maximum of two ink droplets at the minimum recording pixel at a resolution of 360 dpi. The reason why the number of ink droplets is smaller than that in the black processing in the processing 6 is to reduce the emphasis on the edge portion.
This is because two colors of Y, M, and C are superimposed when R, G, and B are recorded, and if the same color is used in the processing 6, the ink is likely to bleed.

STEP 72 shows a process for processing color image data which is not an edge portion. The image data is converted in accordance with the function func of the color maximum printing rate N2. The conversion process was defined and operated as follows.

Dout = f (N2, Din) = DinxN2 Here, the conversion function is the same for black and color, but may be a different function.

At STEP 73, the control proceeds from STEP 69 to ST.
In order to integrate the image data processed in each step of EP72, a logical sum of each data is obtained, and the data is binarized and converted into binary image data. Here, a known error diffusion method is used for the binarization processing, but another method may be used.

At STEP 74, the binarized image data is determined and converted into print data for driving the print head of the printing apparatus.

Here, the determination in STEP 66 is black or color, but another determination may be made. Or,
Other determinations may be made and processed independently. For example, the image processing conditions may be changed for each object or image size. Specifically, it is "character data or graph data" or "not so (natural image data)", or "bit image data" or "not so". In addition, by detecting the size of the character at the time of edge detection, the condition of the processing 6 applied to the edge portion may be changed according to the character size. For relatively small characters, collapse is likely to occur due to changes in character data. Therefore, edge enhancement processing is performed on only one pixel from the edge portion, and for relatively large characters of about 12 points or more, the line density is increased. For this reason, it is desirable to perform the enhancement processing from the edge portion to several pixels.

The processing may be selected depending on the purpose of the desired image quality or recording speed.

In this embodiment, the case where 8-bit image data is input has been described. However, the present invention can be similarly applied to the case of binary image data. The above processing may be performed after converting the binary data into multi-valued data by the conversion processing. Also,
When the binary-to-multivalue conversion process is not performed, for example, 16 × 16
Edge detection and thinning processing may be performed by pattern processing having the mask size of

(Embodiment 7) FIG. 14 is a perspective view of a recording apparatus of Embodiment 7. 1 shows an example of a serial type inkjet color printer to which the present invention is applied.

The print head 1 is a device that has a plurality of nozzle rows and performs image recording by forming dots on a recording medium by discharging ink droplets. In this embodiment, a piezo element, which is an electromechanical converter, is used to positively generate ink droplet diameters of different sizes (that is, different ink ejection amounts). By controlling the voltage value applied to the piezo element, it is possible to eject different amounts of ink from the same nozzle. Further, different color inks are ejected from different print heads, and a color image is formed on a recording medium by mixing colors of these ink droplets. Print head row 1K (black), 1C (cyan),
1M (magenta) and 1Y (yellow) indicate carriage 20
1 and forms an image on a recording medium in this order during one scan in one direction.

The carriage 201 receives power from the carriage drive motor 8 and is transmitted by the belts 6 and 7 to move on a sliding shaft. Printing in the digit direction is performed during the operation in the main scanning direction. The recovery unit 400 has a function of always maintaining the state of the print head in a good state, and in a non-print state, the cap row 420 closes the ejection surface of the print head to prevent drying or the like. Therefore, the carriage 201 is moved to the recovery unit 400.
Is called a home position (hereinafter, HP). In the normal printing operation, the carriage moves from this HP to perform printing, and in this example, printing is performed from left to right in FIG. In the sub-scanning direction, the recording medium is fed by a paper feed motor (not shown). The direction A in the drawing is the paper feeding direction. Reference numeral 9 denotes a flexible cable for supplying an electric signal to the recording head. The ink is supplied from the ink cassettes 10K and 10K mounted on the carriage 201.
C, 10M, and 10Y. The supply of ink is not limited to the configuration shown in the drawing, and a configuration in which a row of tubes for supplying ink is provided in the same manner as a flexible cable from the ink tank provided in the recording apparatus body to supply a print head on the carriage for each color. It may be.

FIG. 15 shows details of the recording head shown in FIG. As a configuration of the recording head, for example,
A recording head having a configuration using an electro-mechanical converter as shown in Japanese Patent Application Laid-Open No. 3-237669 is used. It is possible to obtain two different ink volumes by changing the driving conditions for driving the piezoelectric element by using the piezoelectric element 38 which is an electromechanical variant. The drive condition is to control a voltage value and a drive time, which are conditions for varying the drive energy, and may also be a drive waveform control.

FIG. 16 is a flow chart when ink droplets of different volumes are used. 1 in high-speed recording mode
Recording is performed at a resolution of 360 dpi with a dot ejection volume of 50 ng. On the other hand, in the high quality recording mode, the ejection volume of one dot is set to 30 ng, and recording is performed at a resolution of 720 dpi. The recording operation at a resolution of 720 dpi was performed by the method shown in FIG.

In STEP 81, the input data is separated into data 1 as image data and data 2 as control data, and the flow advances to the next step.

In STEP 82, the image data is divided into recording information and resolution information, and the recording information is sent to the pattern processing section. The resolution information is sent to STEP84.

STEP83 is the control data determining means 20.
2 is shown. Data 2 which is control information of the printing apparatus at the time of the printing operation determined by the printing medium data, the mode data and the environment data is sent to the pattern processing section.

STEP 84 shows the steps in the maximum ink ejection rate determining means 203. From the resolution information and the control information, the maximum ink ejection amount N3 at low resolution and / or the maximum ink ejection amount N4 at high resolution is determined. If the resolution information is high resolution, the high quality recording mode is automatically set. Since the ejection volume of one dot differs between the high-speed recording mode and the high-quality recording mode, it is necessary to set the maximum ink ejection amount independently.

Next, processing is performed in a pattern processing section surrounded by a dotted line so that an optimum recorded image can be obtained from each condition of data 1 and data 2.

STEP 85 shows a multi-value processing step.
If the record information is binary data, the data is converted to multi-value data, and if the record information is multi-value data, the process proceeds to the next step.

In STEP 86, it is determined whether the resolution is low or high based on the resolution information of the image data. If the resolution is low, go to STEP87. If the resolution is high, STE.
Proceed to P88.

STEP 87 and STEP 88 show a process for determining whether or not the image data is an edge portion. S
In STEP 87 and STEP 88, a known edge detection process was performed in this example.

STEP 89 indicates a process for processing the low-resolution data in which the image data is determined to be an edge portion, and the process 8 is performed. As an example of the process 8, a known smoothing process is performed on the edge portion.

STEP 90 shows a process for processing low-resolution data that is not an edge portion. The recording information of the image data is converted based on the maximum ink ejection rate N3 at the low resolution determined in STEP84. In the conversion processing, the input data before the conversion processing is Din, the output data after the conversion processing is Dout, and the conversion function is func, and the calculation processing is defined as follows.

Dout = f (N3, Din) = DinxN3 STEP91 indicates a processing step of high-resolution data determined as an edge portion, and performs processing 9. As an example of the processing 9,
A known smoothing process is performed on the edge portion.

STEP 92 shows a process for processing high-resolution data that is not an edge portion. The recording information of the image data is converted based on the maximum ink ejection ratio N4 at the high resolution determined in STEP84. In the conversion processing, the input data before the conversion processing is Din, the output data after the conversion processing is Dout, and the conversion function is func, and the calculation processing is defined as follows.

Dout = f (N4, Din) = DinxN4 Here, the conversion function is the same function for the low resolution and the high resolution, but it may be a different function.

In STEP 93, the STE is changed from STEP 89.
This is a process of integrating the image data processed in each step of P92. Further, the image data is binarized and converted into binary image data. Here, the binarization processing uses a known error diffusion method, but other methods may be used.

In STEP 94, the image data subjected to the binarization processing is determined, and is converted into print data for driving the print head of the printing apparatus.

As a method for obtaining a different ink ejection amount, a recording head using a piezoelectric element, which is an electromechanical converter, has been described. However, another method may be used. For example, a bubble jet recording head using two electric / thermal mechanical converters may be used.

FIG. 17 is an enlarged front view of the vicinity of the electric / heat converter of the bubble jet recording head for obtaining different ink ejection amounts. Heating element 3 which is an electric-heat converter of the recording head
Numeral 0 is provided with two heating elements H1 and H2 which can generate heat independently for all nozzles. 360 dpi when recording at low resolution, which is the high-speed recording mode
Record at a recording density of At this time, H corresponding to each discharge port
1 and H2 are simultaneously heated. In the case of high-resolution printing in the high-quality printing mode, only the nozzles H1 or H2 are controlled to generate heat, and the volume of each color ink droplet ejected is smaller than in low-resolution printing. Such a print head system that changes the ejection amount in accordance with the resolution makes the effects of the present invention more remarkably exhibited.

(Embodiment 8) FIGS. 18 and 19 show an ink jet recording apparatus capable of recording at m (> n) resolution using an ink jet recording head at n resolution. Means for performing test printing on the predetermined recording medium under a set driving condition in which ink droplets (ink volume × number) within a range not exceeding the maximum ink ejection amount per unit area of the recording medium are provided; Means for correcting the set driving conditions according to an image;
1 is an embodiment of an ink jet recording apparatus having the following. In the ink jet recording method for performing recording with m (> n) resolution using the ink jet recording head with n resolution in each of the above embodiments, the step of converting input data into multi-value data and the printing mode according to the resolution In accordance with the setting process and the resolution, printing conditions including the printing medium, and environmental conditions, the ink droplets (ink volume × ink volume) that do not exceed the maximum ink ejection amount per unit area of the printing medium.
Number) can be set, and the resolution,
Creating binary data for recording in accordance with the converted multivalued data and the set print mode; and using the binary data for recording, an ink droplet having a size corresponding to M resolution under the driving conditions. And a step of performing recording by forming an image on the recording medium.
The description here will focus on the test mode.

In FIG. 19, when predetermined input data is sent, printing is automatically performed, and the image on the recording medium is determined (a known automatic or manual head shading can be used). And the image quality can be further improved. The apparatus may be configured so that it can be operated by a user before shipment of the apparatus or by a user. Alternatively, condition recording of m and n resolutions is printed on the same recording medium with a predetermined test pattern. The determination may be made.

In any case, this embodiment can eliminate many fluctuation factors of the recording head drive, and can solve the problems of the present invention from many aspects. If this test print is performed immediately before high-resolution recording is performed and correction is performed, each of the fluctuation conditions of the recording apparatus, the recording head, the medium to be used, and the like can be canceled, so that high-resolution recording can be performed with higher quality.

(Embodiment 9) FIGS. 20 and 21 correspond to FIGS.
This is an improvement of the ninth embodiment. Basically, a recording medium suitable for changing the resolution is set in advance, and a warning display in STEP 120 is performed on other than this recording medium to indicate that high-resolution recording cannot be sufficiently achieved. Alternatively, this embodiment discloses a step of permitting the execution of the high-resolution recording step on a recording medium other than the designated recording medium by canceling the warning by the user input in STEP 121. The description here is limited to the characteristic portions. In this embodiment, when a recording medium for performing the test print is set in advance in the entire system, a warning can be generated when a different recording medium (user selected) is provided. You can also.

The above-described ink jet recording method uses the method shown in FIG.
STEP 122 to STEP 127 of FIG. The means for determining the recording medium as the medium sensor in the recording apparatus may be performed by various known mark detection, optical detection, or the like. In this way, by predetermining the recording medium on which recording is performed, not only printing waste can be solved, but also the assurance of the recording image quality of the apparatus can be improved.

(Embodiment 10) FIG. 22 shows an ink jet recording apparatus capable of performing recording with m (> n) resolution using an ink jet recording head with n resolution.
According to the resolution, by changing the recording medium or the recording head driving conditions, means for performing recording according to the resolution, and means for stabilizing the recording head according to the change in the resolution, characterized by having In the embodiment of the ink jet recording apparatus, a flowchart applicable to the recording apparatus shown in FIG. 1 and the like is shown.

At step 129, the necessity of resolution conversion is determined.
If there is a resolution conversion as determined in step (1), the head stabilization process is immediately performed in STEP 131, and the data process is converted according to the resolution. In this manner, by performing the head stabilization processing, a head state suitable for resolution can be achieved with good timing, and thus the ink jet recording method (STEP 95 to STEP 102) of the present invention can be further improved. When the ink jet recording method changes the mode from the n-resolution recording to the m-resolution recording, the recording head stabilization processing (for example, head surface cleaning or preliminary ejection,
By providing a step of performing suction recovery or pressure recovery, ink droplets for high resolution can be made to have high precision, so that image quality can be reliably improved. In particular, when ink droplets for high resolution are made relatively small, the effect becomes particularly remarkable.

(Embodiment 11) In the first embodiment, if the maximum ink ejection amount is exceeded for all the input data,
The process of converting to lower the multi-level level to be recorded
Data conversion processing A). For this reason, the output level near the maximum value of the multi-value level of the input data also decreases,
There may be some drawbacks to the record for obtaining the highest density.

Therefore, in the present embodiment, output levels other than near the maximum value of the multi-valued level of input data are lower than the input level. Except near the maximum value, the input data is reduced at the multi-value level or at a rate that does not decrease as much as the reduction rate of the input level other than near the maximum value. The above problem is improved by processing (hereinafter, referred to as data conversion processing B).

FIG. 23 is a diagram showing a specific image data conversion process according to the eleventh embodiment. The input data Din of 8-bit 256 gradations is converted into the output data Dout of 8-bit 256 gradations by general gamma conversion. This example is a case where the recording paper is a specific plain paper based on the above-described reference recording conditions, and a case where N = 0.8. The volume of one ink droplet to be ejected is controlled to be constant at 50 ng. In the case of color recording, the secondary colors R, G, and B are Y,
In order to represent M and C in a superimposed manner, a total of 100 ng is recorded in a unit area of 360 dpi angle. N = 1
In this case, this condition is acceptable, but N = 0.8 is too large. Therefore, the output data Dou is compared with the input data Din.
This is a process for decreasing t. Data conversion processing A is performed to reduce the average ink ejection amount per unit area. For example, a straight line indicated by b is a conversion function.

However, only when the input data Din is 255 which is the maximum value, the output data Dout is assumed to be 255 which is the input data. This processing is different from the data conversion processing A, and is referred to as data conversion processing B. The point of this embodiment is that only the maximum value of the input data Din is processed differently from the others.

As a result, the data conversion function is as shown in FIG.
Is a function in which only the maximum value is P2 indicated by a black circle instead of P1 indicated by a white circle. When the input data Din has the maximum value, printing is performed at a high density even if ink overflows on the printing medium. However, if the overflow exceeds the allowable range, the input data Din
Is 255, which is the maximum value, is not the maximum output data 255 (P2), but P3, which is an extension of the conversion function of "data conversion processing A" and P3 between the above P2. P
3 is a value larger than P1.

By the effect of the data conversion processing B, an image with good gradation is obtained in a gradation image such as a landscape photograph, and an image with a particularly high density is recorded in an image such as a graph.
Optimal processing according to the recorded image was performed.

It should be noted that the conversion function for converting the multi-valued level of the image data is not the straight line shown in FIG.
And a constant (determined depending on N). It is the same that only the maximum value of Din is set to P2.

Further, the conversion function for converting the multi-value level of the image data is not limited to the linear conversion function represented by b or c, but may be a monotonically increasing curve represented by d. This is the same in that only the maximum value of Din is P2.

In any case, if the input data Din is 1 to 254 in the data conversion process,
Out performs "data conversion processing A" for lowering the multi-value level so as to convert the print data into a print data in a range not exceeding the maximum ink ejection amount per unit area according to at least the print resolution and print medium. When the input data Din is 255, which is the maximum value, Dout is “data conversion processing A”.
Perform a "data conversion process" different from that described above.

Further, the "data conversion process B" different from the "data conversion process A" is performed not only when the input data Din is at the maximum value of 255, but also when the input data Din is near the maximum value. Good.

FIG. 24 shows an example in which data conversion processing A is performed for input data 1 to 249, and data conversion processing B is performed for input data 250 to 255 near the maximum value. Show.

The function of the "data conversion process B" is always L1, which is the maximum value, L2, which is a constant value, L3, which is an output equal to the input, and the like. In each case, "Data conversion processing A"
Is smaller than the conversion ratio.

By this processing, a portion having a relatively high density can be printed with a high density, and a portion having a relatively low density can be printed with a lighter density but not overflowing with ink.

Further, the "data conversion processing B" may be performed only on the edge portion of the recorded image. This is advantageous in that, when a relatively large area is densely recorded by a process of recording a relatively high density portion, ink overflow is likely to occur, and this is prevented, and the edge portion can be recorded densely.

Further, the “data conversion processing B” may be performed on “Bk”, “character”, or “Bk character”.

This is because, in particular, the recording of Bk or a character or the character of Bk is more visually noticeable than the others, but the other recordings are less noticeable.

(Embodiment 12) In this embodiment, in low resolution mode such as n resolution, for example, 360 dpi, level conversion of multi-valued data is not performed, and m resolution, for example, 720d
In the high resolution mode such as pi, the data conversion processing A and B described in the eleventh embodiment are performed. Thus, in the high-resolution mode in which the overflow of the ink easily occurs, this can be prevented, and the portion having a relatively high density can be recorded densely.

When the data conversion processing B is applied only to the edge portion of the recorded image, it is possible to prevent the density of the edge portion from decreasing. Further, the data conversion processing B may be applied only to “Bk” or “character”, or only to “Bk character”. The density of the portion to which the data conversion processing B is applied does not decrease even in the high resolution mode.

Each data processing step of the present invention is usually performed by data processing means in the recording apparatus, but is not limited to this. For example, part of the processing may be performed by a host computer outside the recording device.

The present invention particularly provides an excellent effect in a recording apparatus using an ink jet recording head which forms flying droplets by utilizing thermal energy and performs recording, among ink jet recording systems.

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 recording information and giving a rapid temperature rise exceeding 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 the drive signal
This is effective because air bubbles in the interior can be formed. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a 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.

The configuration of the recording head may include a combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications. U.S. Pat. No. 4,558,333 and U.S. Pat.
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.

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 and the ink from the apparatus main body when 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.

It is preferable to add a recording head ejection recovery unit, a preliminary auxiliary unit, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

Also, as for the type and the number of recording heads to be mounted, two or more recording heads may be provided corresponding to a plurality of inks having different recording colors and densities. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

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 lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself 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. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, a form may be adopted in which the liquid sheet or the solid substance is held as a liquid or solid substance in the concave portion or through hole of the porous sheet and faces the 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.

[0160]

According to the present invention, with the above-described configuration, it is possible to perform high-quality recording without blurring which is suitable for input data and a recording medium at the time of resolution conversion, and high-resolution or high-gradation recording becomes possible. Was. According to the present invention, it is possible to provide an inkjet recording method capable of performing high-quality recording according to the characteristics of various recording media including plain paper, regardless of various input image data and various recording conditions. It became.

Further, according to the present invention, it is possible to perform recording with higher resolution than before.

[Brief description of the drawings]

FIG. 1 is a perspective view of a recording apparatus applicable to the present invention.

FIG. 2 is a perspective view of a recording head unit.

FIG. 3 is an enlarged sectional view of a recording head.

FIG. 4 is a block diagram of a recording apparatus applicable to the present invention.

FIG. 5 is a diagram showing a flowchart of the first embodiment.

FIG. 6 is a diagram illustrating an image data conversion process according to the first embodiment.

FIG. 7 is a view showing a flowchart of a second embodiment.

FIG. 8 is a diagram illustrating a flowchart of a third embodiment.

FIG. 9 is a diagram illustrating a flowchart of the fourth embodiment.

FIG. 10 is a diagram showing a flowchart of a fifth embodiment.

FIG. 11 is a diagram illustrating an example in which image data processing according to a fifth embodiment is performed.

FIG. 12 is a diagram showing a flowchart of a sixth embodiment.

FIG. 13 is a diagram illustrating scanning of a recording head according to a sixth embodiment.

FIG. 14 is a perspective view of a recording apparatus according to a seventh embodiment.

FIG. 15 is a diagram showing details of another recording head applicable to the present invention.

FIG. 16 is a flowchart when ink droplets of different volumes are used.

FIG. 17 is a cross-sectional view of a recording head that changes an ink ejection amount.

FIG. 18 is a schematic diagram illustrating a system according to an eighth embodiment.

FIG. 19 is a diagram showing a flowchart of the eighth embodiment.

FIG. 20 is a schematic diagram showing a system according to a ninth embodiment.

FIG. 21 is a diagram showing a flowchart of the ninth embodiment.

FIG. 22 is a flowchart showing a main part of the tenth embodiment.

FIG. 23 is a diagram illustrating image data conversion processing applied to the eleventh embodiment.

FIG. 24 is a diagram illustrating another image data conversion process applied to the eleventh embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 color ink tank 21 black ink tank 22 discharge port surface 23 discharge port 30 heating element 31 recording medium 35 ink droplet 38 piezoelectric element 100 recording device 101 carriage 102 recording head 103 recording head unit 202 control data determination means 203 maximum ink ejection rate determination Means 401 Receive buffer 402 CPU 403 Memory unit 404 Mechanical control unit 405 Mechanical unit 406 Sensor / SW control unit 407 Sensor / SW unit 408 Display element control unit 409 Display element unit 410 Recording head control unit 411 Recording head

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigetasu Nagoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yuji Akiyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Kyano (72) Inventor Fumihiro Goto 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (5)

[Claims] 1. An ink jet recording method for performing recording at a resolution of m (> n) on a recording medium using an inkjet recording head of n resolution, wherein a low resolution recording mode for recording at n resolution and a recording at m resolution. An ink jet recording method comprising: setting a high resolution recording mode; and converting the multilevel data to be recorded so as to lower the density level when the set recording mode is the high resolution recording mode. 2. The method according to claim 1, wherein when the set recording mode is a high-resolution recording mode, the density level other than near the maximum value of the multi-value data to be recorded is converted so as to decrease the level. And converting the density level so as to lower the density level as it is or at a rate smaller than the rate of reduction of the density level other than near the maximum value.
3. The inkjet recording method according to item 1. 3. The method according to claim 1, further comprising the step of determining whether or not the data to be recorded is an end of an image. When is the edge of the image, the density levels other than near the maximum value of the multivalued data to be recorded are converted to lower the level, and the density levels near the maximum value are unchanged or the density levels other than near the maximum value are lowered. When the set recording mode is the high resolution recording mode and the data to be recorded is not at the end of the image, the density level of the multi-value data to be recorded is reduced. 2. The ink jet recording method according to claim 1, wherein the conversion is performed. 4. The method according to claim 1, further comprising the step of determining whether the density level of the multivalued data to be recorded is at or near a maximum value. When the maximum value is not at or near the maximum value, conversion is performed so that the density level of the multi-value data to be recorded is lowered, and when the density level of the multi-value data to be recorded is at or near the maximum value, the multi-value data to be recorded 2. The ink jet recording method according to claim 1, wherein the conversion is performed such that the density level is reduced as it is or at a rate smaller than the reduction rate of the density level other than near the maximum value. 5. The method according to claim 1, further comprising the step of determining whether the data to be recorded is black or another color. The converting step is such that the set recording mode is a high-resolution recording mode and the data to be recorded is black. In the case of, the density level other than near the maximum value of the multi-value data to be recorded is converted so as to lower the level, and the density level near the maximum value is unchanged or at a rate smaller than the reduction rate of the density level other than near the maximum value When the set recording mode is the high-resolution recording mode and the data to be recorded is the other color, the conversion is performed to reduce the density level of the multi-valued data to be recorded. The ink jet recording method according to claim 1, wherein: