JPH10278346A - Ink jet recording system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a clear character having no blur while sustaining the effect for eliminating fluctuation of an image in a print image where a character and an image are mixed. SOLUTION: Characters and other images are separated from a print image (1002) while employing a multipass print method, and they are developed alternately for each column in the main scanning direction (1005, 1006) before being printed while masking such that the column of character image is subjected to single pass printing for completing the image by single time main scanning whereas the column of other image is subjected to multi-pass printing for completing the image by plurality of times of main scanning. Since a character is subjected to single pass print, an image having uniform dot position accuracy is obtained and since a gray scale part is subjected to multipass printing, a uniform image where the fluctuation of dot position accuracy and dot diameter is distributed is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing system and a printing method, and more particularly, to a printing head having a plurality of printing elements for forming dots on a printing medium. The present invention relates to a printing system and a printing method for performing printing by relatively scanning in a direction different from the direction.

[0002]

2. Description of the Related Art In recent years, with the spread of information processing devices such as personal computers, word processors, and facsimile machines in offices and the like, various types of printers have been developed as information visualization output means of those devices. Among them, ink jet printers have advantages such as low operation noise, high quality printing on various types of print media, and easy downsizing. It is suitable.

[0003] In such an ink jet printing apparatus, an ink tank for storing ink and an electric signal are converted into heat by an electro-thermal conversion element, thereby causing film boiling of the ink and bubbles generated by the boiling. The mainstream is a configuration that uses a cartridge that can be exchanged with a print head that causes ink to fly using pressure.

This cartridge has the advantages that the ink supply path length from the print head to the ink tank is shortened, so that the cost can be reduced and the ink consumption at the time of suction recovery can be reduced. I have. Further, if the ink tank holds an amount of ink to be used until the end of the life of the print head, the user replaces the cartridge, thereby performing the maintenance of the ink replenishment and the print head replacement at the same time. There are advantages such as. Furthermore, it is possible to exchange and use the cartridges for color printing and monochrome printing in accordance with the use of the user, and such printing apparatuses have actually been proposed.

[0005] The quality of an image to be printed largely depends on the performance of the print head alone, and slight differences that occur in the print head manufacturing process, such as variations in the shape of the discharge ports of the print head and variations in the electrothermal transducers, are noted. This may affect the ejection amount of the ejected ink and the direction of the ejection direction, and may appear as density unevenness in the finally formed image, thereby deteriorating the image quality.

This will be described in detail with reference to FIGS. 1 and 2.

In FIG. 1A, reference numeral 1101 denotes a so-called multi-nozzle head having a plurality of discharge ports, which is shown as having eight discharge ports for simplicity. An ink droplet 1103 is ejected from the ejection port 1102.
Ideally, the ink is ejected in a state where the directions are aligned. Then, if such ejection is performed, FIG.
As shown in FIG. 1, dots of uniform size land on the print surface of the print medium, and a uniform image without density unevenness can be obtained as a whole (FIG. 1 (c)).

However, in practice, as described above, the discharge port or the liquid path communicating with the discharge port, and the electrothermal transducers (hereinafter referred to collectively as nozzles) disposed in connection with the liquid path. 2), there is a manufacturing variation among the nozzles. If printing is performed without taking this into account, the ink ejected from each ejection port as shown in FIG. The size and direction of the drop vary, and land on the surface to be printed as shown in FIG. According to this figure, there is a blank portion that does not periodically satisfy the area factor of 100% in the main scanning direction of the head, or dots overlap more than necessary, or the image is seen in the center of the figure. Or white streaks that occur. The collection of dots formed in such a state has a density distribution as shown in FIG. 3C in the arrangement direction of the ejection ports, and as a result,
These phenomena are usually perceived by human eyes as density unevenness.

Therefore, as a countermeasure against the density unevenness, for example, a method as disclosed in JP-A-60-107975 has been proposed.

Referring to FIGS. 3 and 4, the method will be described. In order to complete the print area shown in FIGS. 1 and 2, a multi-nozzle head 200 shown in FIG.
1 is scanned three times, but an area of a half of the ejection port arrangement range (four pixels in the figure) is completed in two passes.
The eight nozzles of this multi-nozzle head are divided into groups of four upper nozzles and four lower nozzles, and the dots formed by one nozzle in one scan form predetermined image data in a predetermined image data array. In FIG. 4 (a). In the second scan, dots are embedded in the remaining half of the image data (see FIG. 4).
(B)) The printing of the 4-pixel unit area is completed (FIG. 4C). Such a printing method is hereinafter referred to as a multi-pass or multi-scan printing method.

When such a printing method is used, even if the same one as the multi-nozzle head shown in FIG. 2 is used,
Since the influence of each nozzle on the print image is reduced by half, the printed image is as shown in FIG.
Black streaks and white streaks as seen in (b) become less noticeable.
Therefore, as shown in FIG. 3C, the density unevenness is considerably reduced as compared with the case of FIG.

When such printing is performed, the image data is divided in the first scan and the second scan in such a manner that the image data is mutually filled according to a certain arrangement. 4
As shown in (a) to (c), it is most common to use a pixel having a houndstooth check for each vertical and horizontal pixel. Accordingly, in the unit print area (here, in units of four pixels), printing is completed by the first scan for printing the staggered grid and the second scan for printing the inverted staggered grid.

[0013]

However, by forming an image by a plurality of scans, in a low-cost apparatus employing a relatively inexpensive scanning mechanism, a dot landing position is required for each scan. There is a possibility that it will be slightly deviated from the main scanning direction and the sub-scanning direction. For this reason, when the print image is a character such as a character, a numeral, or a symbol (hereinafter, simply referred to as a character), a figure formed by three print scans with respect to the character of FIG. 5 formed by one print scan. The character No. 6 is in a state where its edge is broken, which leads to deterioration of character quality.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing system and method which can maintain the effect of eliminating unevenness of an image image and eliminate blurring of characters in multi-scan printing.

[0015]

For this purpose, the present invention provides:
A printing system that uses a print head having a plurality of print elements arranged for forming print dots on a print medium and performs printing by relatively scanning the print head in a direction different from the arrangement direction Alternatively, in a printing method, an image separating means or a step of separating first image data for completing an image in one scan and second image data for completing an image in a plurality of scans, and the first image data A first developing unit or a step of developing the second image data as pixels other than the predetermined number of pixels in the scanning direction. Thinning device for thinning image data obtained by the first expansion means and the second expansion means in accordance with a thinning pattern. Or a step, that comprises a the Tokute'.

Here, the first image data is at least one of a character, a character smaller than a predetermined size, a line drawing composed of lines, and a line drawing composed of lines smaller than a predetermined width. May be used as the second image data.

The predetermined number of pixels is an odd-numbered pixel or an even-numbered pixel in the scanning direction, and the thinning-out pattern is performed by scanning the odd-numbered or even-numbered pixel portion in the scanning direction once. Complete the image with
The even-numbered or odd-numbered pixel portions in the scanning direction can be formed into a pattern that completes an image by performing a plurality of scans.

Here, the odd-numbered pixels and the even-numbered pixels in the main scanning direction may be formed so as to be displaced by a half pixel on the print medium.

In the above, the print head may have the form of an ink jet head for performing printing by discharging ink from a discharge port, and the print head discharges ink from the discharge port. As an energy generating element provided to generate the energy used for this purpose, it is possible to have an electrothermal converting element for generating thermal energy for causing film boiling of the ink.

Further, the printing system includes a printing apparatus for performing printing using the print head, and a host apparatus for supplying image data relating to printing to the printing apparatus. Means and the first and second image data developing means, and the printing apparatus is provided with the thinning means, or the host apparatus is provided with the image separating means, and the printing apparatus is provided with the first and second image data developing means. And a second image data expanding unit and the thinning unit.

Further, a printing apparatus according to the present invention is used in the above printing system or method, and is provided with the thinning means or the first and second developing means.

According to the above configuration, it is possible to complete the character portion of the print image by one scan and complete the image other than the character by a plurality of scans. High quality images can be realized.

In this specification, the terms “record” and “print” refer not only to the formation of significant information such as characters and figures, but also to the widespread formation of images, patterns, and patterns on a medium (printing). ).

The term "printing medium" refers to not only paper used in a general recording apparatus but also a wide range of cloth, plastic film, metal plate, etc., which can accept ink ejected by a head. However, in the following embodiments, such a print medium may be symbolically called "paper".

[0025]

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

(First Example) FIG. 7 is a schematic view showing an example of the configuration of a main body of an ink jet apparatus suitable for applying the present invention.

In the figure, the spiral groove 50 of the lead screw 5005 which rotates via the driving force transmission gears 5011 and 5009 in conjunction with the forward and reverse rotation of the drive motor 5013
The carriage 5014 that engages with the carriage 04 has a pin (not shown) and is reciprocated in the directions of arrows a and b. The carriage 5014 has an ink jet cartridge I
JC is mounted. A pressing plate 5002 presses the paper against the platen 5000 in the carriage moving direction. Reference numerals 5007 and 5008 denote home position detecting means for confirming the presence of the lever 5006 provided on the carriage 5014 in this area and switching the rotation direction of the motor 5013. 5
Reference numeral 016 denotes a member for supporting a cap member 5022 for capping the front surface of the print head. Reference numeral 5015 denotes suction means for sucking the inside of the cap, and performs suction recovery of the print head through an opening 5023 in the cap. 5017 is a cleaning blade, 5019 is this blade 5017
Are movable in the front-rear direction, and are supported by the main body support plate 5018. It goes without saying that the blade is not limited to this form, and a well-known cleaning blade can be applied to this embodiment.

Reference numeral 5024 denotes a temperature or humidity sensor.
The temperature or humidity at which the inkjet printing apparatus is installed can be detected. Also, it is possible to predict the temperature of the inkjet print head. This sensor may be attached to the ink jet cartridge IJC,
12, the detection may be performed.

Reference numeral 5021 denotes a lever for starting the suction recovery operation, and a cam 5020 which engages with the carriage.
The driving force from the driving motor is transmitted through a known transmitting means such as clutch switching and the movement is controlled.

The capping, cleaning, and suction recovery are performed so that desired operations can be performed at the corresponding positions by the action of the lead screw 5005 when the carriage comes to the area on the home position side. A desired operation can be performed at a timing.

The ink jet cartridge IJ in this embodiment
C is a shape in which the ink storage ratio is large, and has a shape in which the tip of the ink jet unit 5012 projects slightly from the front surface of the ink tank 5001.
The inkjet cartridge IJC is fixedly supported by appropriate positioning means and electrical contacts on a carriage 5014 provided in the inkjet printing apparatus main body IJRA, and the carriage 501
4 is detachable.

FIG. 8 is a schematic view of a heater board 100 of a head, which is a component of the ink jet unit 5012 used in this embodiment. The illustrated heater board includes a temperature control heater (sub-heater) 8d that generates thermal energy used to control the temperature of the head, and a discharge heater (sub-heater) that generates thermal energy used to discharge ink. Ejection unit row 8g in which main heaters 8c are arranged
The drive element 8h and a connector 853 for supplying power to the drive element 8h are formed on the same substrate in a positional relationship as shown in FIG. By arranging each element on the same substrate in this manner, the head temperature can be detected and controlled efficiently, and the head can be made more compact,
The manufacturing process can be simplified.

FIG. 3 also shows the positional relationship of the outer peripheral wall cross section 8f of the top plate, which is divided into a region where the heater board is filled with ink and a region where the heater board is not filled. The discharge heater 8d side of the outer peripheral wall section 8f of the top plate functions as a common liquid chamber. A liquid passage is formed by a structure formed on the discharge section row 8g of the outer peripheral wall cross section 8f of the top plate.

Next, the configuration of a control system for executing print control and the like of the above-described apparatus will be described.

FIG. 9 is a block diagram showing a schematic configuration of a control system of the entire apparatus. In the figure, reference numeral 10 denotes an interface for inputting an image signal or the like relating to printing from a host device or the like, reference numeral 11 denotes an MPU for controlling each unit in accordance with a processing procedure described later, and reference numeral 12 denotes a control program executed by the MPU 11. R0M and 13 are dynamic RAMs for storing various data (such as the print signal and print data supplied to the head), and also store the number of print dots, the number of ink print head replacements, and the like. Can be. A gate array 14 controls supply of print data to the print head 18, and includes an interface 10, an MPU 11, and a DR.
It also controls data transfer between the AMs 13.

Reference numeral 17 denotes a carriage 501 on which the print head 18 or the ink jet cartridge IJC is mounted.
Reference numeral 19 denotes a driver for controlling the driving of a motor 5013 serving as a rotational driving source for scanning the scanning unit 4; Reference numeral 15 denotes a head driver for driving the head.

FIG. 10 is a circuit diagram showing details of each of the units 14 to 16 in FIG.
41, a segment (SEG) shift register 142, a multiplexer (MPX) 143, a common (COM) timing generation circuit 144, and a decoder 145.

The print head 18 has a diode matrix configuration, and discharge heaters (H1) where the common signal COM and the segment signal SEG coincide with each other.
To H64), the ink is heated and the ejection operation is performed. The decoder 145 decodes the timing generated by the common timing generation circuit 144 and selects one of the common signals COM1 to COM8.

The data latch 141 latches the print data read from the RAM 13 in units of 8 bits, and the multiplexer 143 stores the print data in accordance with the segment shift register 142 in accordance with the segment signal SEG.
1 to SEG8.

The output from the multiplexer 143 can be variously changed according to the contents of the shift register 142, such as 1-bit unit, 2-bit unit, or all 8 bits, as described later.

The operation of the control system will be described. When a print signal is input from the host device to the interface 10,
A print signal is converted between the gate array 14 and the MPU 11 into print data for a printing apparatus. Then, the motor drivers 16 and 17 are driven, and the print head 18 is driven according to the print data sent to the head driver 15 to perform printing.

FIG. 11 is a diagram for explaining the flow of print data inside the printing apparatus.

The print data sent from the host computer H is stored in the reception buffer RB inside the printing apparatus via the interface 10. Here, the reception buffer RB has a capacity of several k to several tens k bytes.
For the print data stored in the reception buffer RB,
The command is analyzed by the command analysis unit CA and then sent to the text buffer TB. Text buffer TB
Inside, print data is held as an intermediate format for one line, and processing to add the print position, decoration type, size, character (code), font address, etc. of each character is performed. The capacity of the text buffer TB can be varied depending on the model of the printing apparatus. For example, a serial printer can have a capacity of several lines, and a page printer can have a capacity of one page.

Further, the print data stored in the text buffer TB is expanded and stored in the print buffer PB in a binarized state, and a signal is sent to the print head as print data to perform printing.

Some types of printing apparatuses do not have a text buffer, but develop print data stored in a reception buffer at the same time as command analysis and write the data in the print buffer.

The operation of the first example will be specifically described below with reference to FIGS.

In this example, the number of print elements is 64, and the feed amount of the print medium in the sub-scanning direction for each scan is set to 32 pixels, that is, the print image is completed in two scans. Hereinafter, a pixel unit in the main scanning direction of the print head is referred to as a column, and a pixel unit in the sub-scanning direction is referred to as a raster.

FIG. 12 is a diagram showing the means for realizing the operation in this example along the processing flow.

In this example, the output image 1001 is formed, and the character image 1003 and the other image 1
004 is configured in the host computer. This is because the character image and the other image images can be easily separated from the processing instructions for forming the output image.

Next, an image is developed in the image storage means 1007 on the host side. A means 1006 for developing a character image in an odd column of the image storage means 1007 and a means 1005 for developing other image images in an even column Is configured. As a result, the character image and the other image images are stored alternately for each column in the image storage unit 1007.

Next, the transfer means 1008 transfers the image data to the printing apparatus. The printing apparatus receives the image data by the receiving unit 1009, and
10, the received image is developed in the image storage means 1011.

Next, using the mask means 1012, the logical product (AND) of the image and the mask pattern in the storage means 1011 is calculated. Then, based on the data obtained by the masking means, the printing element is driven by the printing means 1013 to form an image.

FIG. 13 shows an example of a mask pattern in the mask means 1012. The mask in this example is 8 columns / 4
A mask is applied to a print buffer that stores an image to be printed using a raster pattern. FIG.
(A) is used in odd-numbered print scans, and (b) is used in even-numbered print scans. That is, the mask of the pattern of FIG. 13A and the mask of FIG.
Are alternately applied to the print buffer.

13 (a) and 13 (b), the column numbered "1" in the figure corresponds to the (8i + 1) th column (where i is an integer of 0 or more) of the print buffer. Similarly, the column numbered "n" in the figure corresponds to the 8i + nth (i is an integer of 0 or more, n is an integer of 0 to 7) of the print buffer. Also, the raster with the sign "a" in the figure corresponds to the 4j + 1th raster (where j is an integer of 0 or more) in the print buffer, and similarly, the 4j + 2th to 4j + 4th rasters (where j is The rasters assigned the reference signs “b” to “d” in the figure correspond to the rasters (integer of 0 or more).

When printing on a print medium by the printing means 1013 using the image data obtained from the mask means, the driving cycle of the printing element is determined by the dot spacing determined by the dot diameter of the printing pixels and the scanning speed of the print head. I do.

For example, when print pixels are formed at a density of 100%, dot intervals are set as shown in FIG. When the dot interval is L and the scanning speed of the print head is v, the driving cycle of the printing element is L / v.

In this embodiment, the interval between the pixels in the print buffer and the print pixels on the print medium is half the normal dot interval L as shown in FIG. That is, the relationship between the drive cycle T of the print element and the scan speed v of the print head is set so that v × T = L / 2.

Further, at the same time as switching the mask pattern during one print main scan of the print head, the print medium is conveyed by 32 rasters in the sub-scan direction, and is referred to drive the print head in the next print scan. The position of the print buffer to be moved is also moved by 32 rasters. As a result, the characters in the print image are
Since the image is printed in one main scan (one pass) when the mask of the pattern (a) is set, an image with uniform dot position accuracy is obtained, while the gray scale portion is subjected to a plurality of main scans (this example). In this case, the image is printed in two passes), so that an image having no unevenness in which the dispersion of the dot position accuracy and the dot diameter is diffused can be realized. Therefore, it is possible to realize high quality of the image in which both the character and the gray scale portion exist. Also,
According to this example, the printing apparatus main body does not need to determine the character image portion and the other image image portions, and the printing method of the character image portion and the other image image portion can be performed in one pass only by setting the mask pattern. It is possible to switch between printing and multi-pass printing.

In this embodiment, the development of the character image portion is performed by odd columns, and the development of the other image portions is performed by even columns. However, the columns to be developed may be reversed, and the number of print elements may be reversed. The number of print passes can also be selected as appropriate, and a mask pattern according to this can be adopted as a matter of course.

The configuration shown in FIG. 12 can be realized by hardware using logic elements, arithmetic elements, and the like.
At least a part of it may be realized by software,
In this case, a program corresponding to the processing procedure and fixed data such as a required pattern are stored in a ROM of a control system which the host apparatus and the printing apparatus generally have, and the CPU
May execute the procedure.

(Second Example) FIG. 16 is a diagram showing means for realizing the operation in the second example of the embodiment of the present invention along a processing flow. This embodiment is particularly different from the first embodiment in that the printing of the character image into the odd-numbered columns and the expansion into the even-numbered columns are performed on the printing apparatus main body side.

First, in this embodiment, a means 2002 for forming the output image 2001 and separating the character image 2003 from the other image images 2004 is provided in the host computer. This is because, similarly to the first example, the character image and the other image images can be easily separated from the processing instruction for forming the output image.

Next, the image data is transferred to the main body of the printing apparatus by the transfer means 2005. At this time, a code for distinguishing a character image from other image images is added to the image data.

The printing apparatus receives the image data from the receiving unit 20.
06, the character image data is sent to the odd-numbered column developing unit 2007, and the other image images are sent to the even-numbered column developing unit 20 according to the code added to the image data.
Send to 08. Then, the odd-numbered column developing unit 2007 develops the image data in the odd-numbered column of the print buffer, which is the image storage unit 2009, and the even-numbered column transferring unit 2
008 develops image data in even-numbered columns of the print buffer. As a result, in the image storage means 2009, the character image and the other image images are stored alternately for each column.

Next, a logical product (AND) of the image and the mask pattern in the storage means 2009 is calculated using the mask means 2010. Then, based on the data obtained by the masking means, the printing element is driven by the printing means 1013 to form an image.

Masking means 2010 and printing means 2
011 is the same as the masking unit 1012 and the printing unit 1013 of the first example, respectively, and the description is omitted.

According to this embodiment, the means for developing a character image in odd columns and the means for developing an image in even columns are provided on the printing apparatus main body side, so that powerful bit operations can be performed by hardware of the printing apparatus main body. And the load on the host can be reduced.

(Third Example) With the development of so-called multimedia today, characters can be handled in a variable size. The present inventors have found that the problem that the quality is degraded during multi-pass printing occurs in characters having a height of about 1 cm or less in 360 DPI (dot / inch) printing. Therefore, in a third example of the embodiment of the present invention, a character image having a size equal to or less than the above size to be printed is printed in one pass, and the other images are printed in multi-pass.

FIG. 17 is a diagram showing means for realizing the operation in the third example along a processing flow.

In this example, the output image 2101 is formed, and the character image 2104 and the other image 2
A means 2102 for separating the data from the host computer 105 is configured on the host computer side. This is because a character image and another image image can be separated more easily than a processing instruction for forming an output image.

Next, means 21 for determining the size of the printed character
In step 05, characters of a specific size or more and characters of a specific size or less are discriminated.

Next, an image is developed in the image storage means 2108 on the host side. A means 2106 for developing a character image smaller than a specific size in an odd column of the image storage means 2108
Means 2107 for developing other image images and character images of a specific size or more into even columns.
As a result, in the image storage unit 2108, the character images smaller than the specific size, the other image images, and the characters larger than the specific size are stored alternately for each column.

The following describes each means or process 1008 of the first example.
Means or processing 2109 to
By employing 2114, only characters smaller than a specific size can be printed in one pass.

In the embodiment described above, only the character image is subjected to one-pass printing.
An image such as a line drawing composed of lines such as an elliptical circumference and a polygonal side, or a line drawing whose line width is smaller than a specific size (for example, 4 dot width) can also be targeted. Like the character size determination described above, a desired process can be easily realized by developing such an image in an even or odd column of the storage unit 2108 according to the attribute of the image.

(Others) The present invention can be applied not only to the ink jet system but also to various other printing systems such as a thermal transfer system. It is excellent in print heads and printers of a type that includes means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ejection, and in which a state change of ink is caused by the thermal energy. The effect is brought about. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical structure 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. Applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding the nucleate boiling, causing the electrothermal transducer to generate thermal energy, causing film boiling on the heat acting surface of the printhead. This is effective because bubbles can be formed in the liquid (ink) corresponding to this drive signal on a one-to-one basis. Due to the growth and contraction of this bubble, the liquid (ink)
To form at least one droplet. When this drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the liquid (ink) having particularly excellent responsiveness can be obtained.
Discharge can be achieved, which is more preferable. As the pulse-shaped drive signal, US Pat. No. 4,463,359,
The one described in the specification of US Pat. No. 4,345,262 is suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the print head, in addition to the combination configuration (straight liquid flow path or right-angled liquid flow path) of the discharge port, liquid path, and electrothermal converter as disclosed in each of the above-mentioned specifications, A configuration using U.S. Pat. No. 4,558,333 or U.S. Pat. No. 4,459,600, which discloses a configuration in which a heat acting portion is arranged in a bending region, is also included in the present invention. In addition, for multiple electrothermal transducers,
JP-A-59-123670 which discloses a configuration in which a common slit is used as a discharge portion of an electrothermal transducer and JP-A-59-123670 which discloses a configuration in which an opening for absorbing a pressure wave of heat energy corresponds to a discharge portion. The effect of the present invention is effective even in a configuration based on JP-A-138461. That is, according to the present invention, recording can be performed reliably and efficiently regardless of the form of the print head.

In addition, as a form of a serial type printer as in the above example, a print head fixed to the apparatus main body, or an electric connection with the apparatus main body by being attached to the apparatus main body, or a connection from the apparatus main body, The present invention is also effective when a replaceable chip-type print head capable of supplying the above ink or a cartridge-type print head in which an ink tank is provided integrally with the print head itself are used.

It is preferable to add a print head discharge recovery unit, a preliminary auxiliary unit, and the like as the configuration of the printer of the present invention since the effects of the present invention can be further stabilized. Specifically, heating is performed on the print head using capping means, cleaning means, pressurizing or suction means, an electrothermal converter, 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.

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

In addition, in the example described above, the ink is described as a liquid. However, an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. In general, in the ink jet method, the temperature of the ink itself is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. A liquid may be used. 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 solidifying when it reaches 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. The ink in such a case is disclosed in
JP-A-4-56847 or JP-A-60-71260.
As described in Japanese Patent Application Laid-Open Publication No. H10-205, a configuration may be adopted in which a liquid sheet or a solid substance is held in a concave portion or a through hole of a porous sheet so as to face an electrothermal converter. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

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

[0083]

As described above, according to the present invention,
It has become possible to perform high-quality printing with clear character portions, while employing multi-scan printing that performs printing without unevenness on a grayscale image.

[Brief description of the drawings]

FIGS. 1A to 1C are explanatory diagrams showing a dot formation mode and a density distribution by an ideal multi-nozzle head.

FIGS. 2A to 2C are explanatory diagrams showing a dot formation mode and a density distribution by a multi-nozzle head having nozzle variations.

FIGS. 3A to 3C are explanatory diagrams showing a dot formation mode and a density distribution by a multi-pass printing method.

FIGS. 4A to 4C are explanatory diagrams for explaining a form of sequential printing dots in a sequential scanning process by a multi-pass printing method.

FIG. 5 is an enlarged view showing an example of a character formed by one print scan.

FIG. 6 is an enlarged view showing an example of a character formed by a plurality of print scans.

FIG. 7 is a schematic view illustrating an example of a configuration of a main body of an inkjet apparatus suitable for applying the present invention.

FIG. 8 is a schematic diagram illustrating a configuration example of a heater board of an inkjet head used in an embodiment of the present invention.

9 is a block diagram illustrating a schematic configuration example of a control system of the entire printing apparatus in FIG. 7;

FIG. 10 is a circuit diagram showing a detailed configuration example of a main part of FIG. 9;

FIG. 11 is a diagram for explaining a flow of print data inside the printing apparatus of FIG. 7;

FIG. 12 is a diagram showing means for realizing the operation in the first example of the embodiment of the present invention along a processing flow.

FIGS. 13A and 13B are explanatory diagrams showing mask patterns used in the first example.

FIG. 14 is an explanatory diagram showing dot formation intervals when print pixels are formed at a density of 100%.

FIG. 15 is an explanatory diagram showing dot formation according to a first example.

FIG. 16 is a diagram showing means for realizing the operation in the second example of the embodiment of the present invention along a processing flow.

FIG. 17 is a diagram showing means for realizing the operation in the third example of the embodiment of the present invention along a processing flow.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Interface 11 MPU 12 ROM 13 RAM 14 Gate array 15 Head driver 16, 17 Motor driver 18, 1101 Print head 1001, 2001, 2101 Output image 1002, 2002, 2102 Image separation means 1005, 2008, 2107 Even column developing means 1006 2007, 2106 Odd column developing means 1007, 2108 Image storing means 1008, 2005, 2109 Transfer means 1009, 2006, 2110 Receiving means 1010, 2111 Image developing means 1011, 2009, 2112 Image storing means 1012, 2010, 2113 Masking means 1013 2011, 114 Printing means 1102 Discharge port 1103 Ink droplet 2105 Character size discriminating means H Host computer Over data

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiichiro Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Daigoro Kanematsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside the corporation

Claims (15)

[Claims] 1. A print head having a plurality of print elements arranged for forming print dots on a print medium, and the print head is relatively scanned in a direction different from the arrangement direction. In a printing system for performing printing, an image separating unit that separates first image data that completes an image by one scan and second image data that completes an image by a plurality of scans, and the first image data First expanding means for expanding the image data as pixels at every predetermined number in the scanning direction; second developing means for expanding the second image data as pixels other than the pixels at every predetermined number in the scanning direction; A thinning means for thinning out the image data obtained by the expanding means and the second expanding means in accordance with a thinning pattern. Cement system. 2. The method according to claim 1, wherein the predetermined number of pixels are odd-numbered or even-numbered pixels in the scanning direction, and the thinning pattern is scanned once for odd-numbered or even-numbered pixels in the scanning direction. 2. The printing system according to claim 1, wherein the pattern is such that an image is completed by a plurality of scans for an even-numbered or odd-numbered pixel portion in the scanning direction. 3. The first image data is at least one of a character, a character having a size smaller than a predetermined size, a line drawing composed of a line, and a line drawing composed of a line having a width smaller than a predetermined width. 3. The print system according to claim 1, wherein the second image data is used. 4. The pixel according to claim 2, wherein the odd-numbered pixels and the even-numbered pixels in the main scanning direction are formed so as to be displaced by a half pixel on the print medium. Print system. 5. A printing apparatus for performing printing using the print head, and a host apparatus for supplying image data related to printing to the printing apparatus, wherein the host apparatus has the image separating unit and the first device. 5. The print system according to claim 1, further comprising: a second image data developing unit; and the thinning unit provided in the printing apparatus. 6. A printing apparatus for performing printing using the print head, and a host apparatus for supplying image data relating to printing to the printing apparatus, wherein the host apparatus is provided with the image separating unit, 5. The printing system according to claim 1, wherein the printing apparatus is provided with the first and second image data developing means and the thinning means. 7. The print system according to claim 1, wherein the print head has a form of an ink jet head that performs printing by discharging ink from a discharge port. 8. The print head, as an energy generating element provided for generating energy used for discharging ink from the discharge port, an electric heat generating thermal energy for causing film boiling of the ink. The printing system according to claim 7, further comprising a conversion element. 9. A printing apparatus used in the printing system according to claim 5. Description: 10. A print head having a plurality of print elements arranged for forming print dots on a print medium, and the print head is relatively scanned in a direction different from the arrangement direction. In a printing method for performing printing, an image separating step of separating l image data that completes an image by one scan and second image data that completes an image by a plurality of scans, and the first image data A first development step of developing the second image data as pixels other than the predetermined number of pixels in the scanning direction, a first development step of developing A thinning step of thinning out image data obtained in the expanding step and the second expanding step according to a thinning pattern. Door way. 11. The method according to claim 1, wherein the predetermined number of pixels are odd-numbered or even-numbered pixels in the scanning direction, and the thinning-out pattern is performed by scanning once for odd-numbered or even-numbered pixels in the scanning direction. 11. The printing method according to claim 10, wherein the pattern is a pattern that completes an image by a plurality of scans for an even-numbered or odd-numbered pixel portion in the scanning direction. 12. The method according to claim 12, wherein the first image data is a character,
5. The image processing apparatus according to claim 2, wherein at least one of a character having a size smaller than a predetermined size, a line drawing composed of lines, and a line drawing composed of lines smaller than a predetermined width is used, and the other image data is used as the second image data. 12. The printing method according to 10 or 11. 13. The printing apparatus according to claim 11, wherein the odd-numbered pixels and the even-numbered pixels in the main scanning direction are formed so as to be displaced by a half pixel on the print medium.
Or the printing method according to item 12. 14. The printing method according to claim 10, wherein the print head has a form of an ink jet head that performs printing by discharging ink from a discharge port. 15. The print head, as an energy generating element provided for generating energy used for discharging ink from the discharge port, an electric heat generating thermal energy for causing film boiling of the ink. The printing method according to claim 14, further comprising a conversion element.