JP2984432B2 - Printer control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer control device for controlling a printer which scans a recording head and records an image on a recording medium.

[0002]

2. Description of the Related Art Conventionally, when recording low-resolution image data using a high-resolution printer, if the image data is output to a printer as it is and recorded, the size of the recorded image is reduced. For this reason, image data is interpolated or thinned out and converted so that the resolution of the image data is apparently increased. FIG. 16 is a diagram showing an example of such conventional resolution conversion of image data.
6 (A) and 6 (B) show a state where 200 dpi image data (A) arranged one-dimensionally is converted into 360 dpi image data (A). Here, in order to simplify the description, the converted image data (a) is also shown one-dimensionally.

[0003] As shown in this figure, the resolution is 200 dpi.
In order to convert the image data (A) into image data with a resolution of 360 dpi, first, as shown in FIG. 16A, the original image data (A) is thinned out to 9/10 and then doubled. . That is, of the first to tenth pixels, 1
The 0th pixel is thinned out, and each of the other pixels is doubled. Another method is as shown in FIG.
One pixel out of five is not converted and the other pixels are doubled. That is, there are two methods in which the first to fourth and sixth to ninth pixels are doubled, and the fifth and tenth pixels are left as they are. As described above, in the case of FIG. 16A, the operations of thinning and interpolation are performed, and in the case of FIG. 16B, the operation of interpolation is performed.
No faithful image conversion was performed.

FIG. 1 shows an example of printing such an image.
7 shows the case where the resolution is converted by the method shown in FIG. In FIG. 17, FIG.
Indicates an original image (200 dpi), and FIG. 17B shows a resolution 360 recorded by conversion according to the method shown in FIG. 16B.
4 shows a recorded image of dpi. 171 in FIG. 17 (B)
Not only does image distortion occur as shown at １７174, but there is a lot of jaggies despite recording at 360 dpi resolution as shown at 175 and dimensional misalignment as shown at 175 (200 dpi resolution). (It does not change) It became an image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and is intended for image data having a resolution different from a predetermined resolution of a printer, which is close to the predetermined resolution and which does not require thinning of the image data. An object of the present invention is to provide a printer control device capable of recording a high-quality image by converting the image data into an image data and recording the image data.

[0006]

[0007]

In order to achieve the above object, a printer control device according to the present invention has the following arrangement. That is, a printer control device that controls a printer that scans a recording head and records an image on a recording medium at a predetermined resolution based on image data, and changes the scanning speed of the recording head to convert the image data into the image data. Recording control means capable of recording at a resolution different from the predetermined resolution, and when the resolution of the input image data is different from the predetermined resolution, the resolution of the image data is close to the predetermined resolution, and Converting means for converting the image data into image data having a resolution that can be converted without requiring thinning, wherein the recording control means scans the recording head at a scanning speed corresponding to the resolution of the image data converted by the converting means. Then, control is performed so as to record the image data whose resolution has been converted by the conversion means.

[0008]

In the above configuration, when the resolution of the input image data is different from the predetermined resolution, the resolution of the image data is close to the predetermined resolution, and the resolution of the resolution which can be converted without the need for thinning out the image data. The image data is converted into image data, the recording head is scanned at a scanning speed corresponding to the resolution of the converted image data, and control is performed so as to record the image data whose resolution has been converted.

[0009]

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

FIG. 7 is an external perspective view showing an example of a system using the apparatus according to the present embodiment. The printer M9 is connected to the apparatus M1 via an interface cable, and prints based on a signal from the apparatus M1. This device M1 is roughly divided into a main unit M1, a display unit M2, a keyboard M
3, a handset unit M4 is provided.

The main unit M1 is composed of a bottom cover M5, a main cover M6, and an upper cover M7, in which a control circuit such as a CPU board and an external interface are provided. A floppy disk drive, a hard disk drive, a speaker and the like are arranged. In addition, a document reading unit (hereinafter, referred to as a scanner) can be arranged as an option on the back side of the main unit M1.

In this system configuration, the printer M9
Accordingly, facsimile reception images, document data created by a word processor or the like can be printed. This printer M
9 is 360 dpi × 360 dpi in this case, the characters of the word processing document are converted to a character size of 10.5.
, High-definition recording can be performed with 48 dots × 48 dots. The resolution of the facsimile reception image is 200 ×
Since the resolution is 200 dpi, high-quality printing can be realized by image conversion for high image quality according to the present embodiment and printing control of the printer.

FIG. 2 is an exploded perspective view showing the internal structure of the printer M9 shown in FIG.

Reference numeral 9 denotes a head cartridge having an ink jet recording head, which will be described in detail later with reference to FIG. 4, and reference numeral 11 denotes a carriage on which the cartridge is mounted and scans in the S direction (sub-scanning direction) in the drawing. . Reference numeral 13 denotes a hook for attaching the head cartridge 9 to the carriage 11, 1
5 is a lever for operating the hook 13. Reference numeral 19 denotes a support plate that supports an electrical connection to the head cartridge 9. Reference numeral 21 denotes a flexible cable for connecting the electric connection unit and the main body control unit. 23 is a guide shaft for guiding the carriage 11 in the S direction,
It is inserted into a bearing 25 of the carriage 11. Reference numeral 27 denotes a timing belt to which the carriage 11 is fixed and which transmits power for moving the carriage 11 in the S direction, and is stretched around pulleys 29A and 29B arranged on both sides of the apparatus. Here, a driving force is transmitted from the carriage motor 31 to the pulley 29B via a transmission mechanism such as a gear.

Reference numeral 33 denotes a platen roller for regulating a recording surface of a recording medium such as paper (hereinafter, also referred to as recording paper) and transporting the recording medium during recording or the like. Reference numeral 37 denotes a paper pan for guiding the recording medium to a recording position by a sheet feeding tray (not shown). Reference numeral 39 denotes a paper pan which is disposed in a recording medium feeding path and presses the recording medium toward a platen roller 33. It is a feed roller for conveying. Reference numeral 41 denotes a discharge roller that is disposed downstream of the recording position in the transport direction of the recording medium and discharges the recording medium toward a discharge port (not shown). Reference numeral 42 denotes a spur provided corresponding to the paper discharge roller 41, which presses the roller 41 via the recording medium to generate a conveyance force of the recording medium by the paper discharge roller 41. Reference numeral 43 denotes a release lever for releasing the urging of each of the feed roller 39, the pressing plate 45, and the spur 42 when setting a recording medium or the like.

Reference numeral 45 denotes a pressing plate for suppressing the floating of the recording medium in the vicinity of the recording position and ensuring the state of close contact with the platen roller 33. On this side, an ink jet recording head that performs recording by discharging ink is employed as a recording head. Therefore, the distance between the ink discharge port forming surface of the recording head and the recording surface of the recording medium is relatively small, and the distance must be strictly controlled to avoid contact between the recording medium and the discharge port forming surface. Therefore, the arrangement of the holding plate 45 is effective.

Reference numeral 51 denotes a cap formed of an elastic material such as rubber facing the ink discharge port forming surface of the recording head at the home position, and is supported so as to be capable of coming into contact with and detaching from the recording head. The cap 51 is used for protection of the recording head at the time of recording and the like, and for ejection recovery processing of the recording head. This ejection recovery process is to drive the energy generating element provided inside the ink ejection port and used for ink ejection to eject ink from all ejection ports, thereby causing bubbles, dust, and thickening. This is a process (preliminary ejection) for removing an ejection failure factor such as ink that is no longer suitable for printing, or a process for removing the ejection failure factor by forcibly ejecting ink from an ejection port separately from this.

Reference numeral 53 denotes a suction force for forcibly discharging the ink, and a cap 5 for performing a discharge recovery process by the forced discharge and a discharge recovery process by the preliminary discharge.
1 is a pump used to suck the ink received. Reference numeral 55 denotes a waste ink tank for storing the waste ink sucked by the pump 53, and reference numeral 57 denotes a tube that connects the pump 53 and the waste ink tank 55.

Reference numeral 59 denotes a blade for wiping the ejection port forming surface of the recording head, which protrudes toward the recording head and engages with a position for wiping in the process of moving the recording head and engages with the ejection port forming surface. It is movably supported with no retracted position. Reference numeral 61 denotes a recovery motor, and reference numeral 63 denotes a cam device for receiving the power transmitted from the recovery motor 61 and driving the pump 53 and moving the cap 51 and the blade 59, respectively.

Reference numeral 64 denotes a photo sensor for detecting the home position of the carriage 11, which is shielded from light by a light shielding plate (not shown) provided on the lower surface of the carriage 11, and emits a signal. The pulse count value of the carriage motor 31 is converted based on this signal, and is reset to 0 pulse when the carriage motor 31 is at the home position.

FIG. 3 is a block diagram showing a schematic configuration of the printer M9, and portions common to the above-mentioned drawings are denoted by the same reference numerals.

In FIG. 3, reference numeral 65 denotes a printer controller, which controls each unit based on image data from the host M1 and performs recording. Reference numeral 66 denotes a head drive circuit, which controls a voltage applied to each discharge heater corresponding to each of the 64 nozzles.

Next, the details of the head cartridge 9 will be described.

FIG. 4 is a perspective view of the head cartridge 9 used in the printer M9 of the present embodiment, which is of a disposable type in which an ink storage unit as an ink supply source is integrated.

The recording head 17 of the cartridge 9
Is provided with a heater board (not shown) in which an electrothermal conversion element (ejection heater) and wiring such as gold (Au) for supplying electric power are formed on a silicon (Si) substrate by a film forming technique. ing. The recording head 17 has a supply tank, receives ink supply from an ink storage unit 47 serving as an ink supply source, and functions as a subtank for guiding ink to a common liquid chamber formed by joining a heater board and a top plate.
The ink reservoir 47 contains an absorber for impregnating the ink, and is arranged in the ink tank body 9b. Reference numeral 49 denotes an atmosphere communication port provided in the lid member for communicating the inside of the cartridge 9 with the atmosphere. A liquid-repellent material is disposed inside the air communication port 49, thereby preventing ink from leaking from the air communication port 49.

The ink is supplied from the inside of the cartridge 9 into the supply tank constituting the recording head 17 from the supply port, and after passing through the inside, the appropriate supply pipe and the ink introduction port of the top plate are connected from the outlet. The ink flows into the common liquid chamber via the common liquid chamber. Then, based on a predetermined print signal, the discharge heater is caused to generate heat, and the thermal energy is used to discharge ink to obtain a desired print image.

FIG. 5 is a diagram showing an example of the nozzle arrangement of the recording head 17 of the embodiment.

In FIG. 5, 64 nozzles from number to (64) are arranged in one row in the N direction (main scanning direction). Here, the interval a between the nozzles is 1/360 inch, that is, it corresponds to a resolution of 360 dpi. Then, the recording head 17 moves together with the carriage 11 in the direction of the arrow S, that is, in the sub-scanning direction by the rotation drive of the carriage motor 31 shown in FIG. 2, thereby enabling two-dimensional image formation.

The amount of recording paper transported by the paper transport motor 35, which is executed each time the carriage 11 scans, corresponds to the length of the nozzle row. That is, the recording paper is conveyed for each scan by the length (64/360 inch) corresponding to the length of the image formed by ejection from the 64 nozzles in the main scanning direction, that is, 64 dot pitches, and the next row. I am preparing for the record.

The printer M9 uses a recording head and a recording apparatus of a bubble jet system among the ink jet recording systems as described above. According to such a method, it is possible to achieve higher recording density and higher reproduction.

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 of the continuous type, in particular, in the case of the on-demand type, an electrothermal transducer arranged corresponding to a sheet holding a liquid (ink) or a liquid path, By applying at least one drive signal that provides a rapid rise in temperature exceeding the nucleate boiling corresponding to the recorded information, heat energy is generated in the electrothermal transducer and film boiling occurs on the heat-acting surface of the recording head. As a result, the liquid (ink) corresponding to this drive signal on a one-to-one basis
This is effective because air bubbles inside 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.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angle liquid flow path) as disclosed in the above specification,
U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is disposed in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, JP-A-59-123670 discloses a configuration in which a slit common to a plurality of electrothermal transducers is used as a discharge section of the electrothermal transducer, or an aperture that absorbs pressure waves of thermal energy is discharged. A configuration based on JP-A-59-138461, which discloses a configuration corresponding to each unit, may be employed. That is, the recording can be performed reliably and efficiently regardless of the form of the recording head.

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

Regarding the type and number of recording heads to be mounted, for example, in addition to the recording head having only one recording head corresponding to a single color ink, the recording head also corresponds to a plurality of recording heads having different recording colors and densities. A plurality may be provided.

FIG. 6 shows the host M1 of the system of this embodiment.
FIG. 2 is a block diagram showing a schematic configuration of FIG. Hereinafter, each unit in FIG. 6 will be described.

Reference numeral 71 denotes a CPU which has a role of controlling and calculating the entire system.
The operating frequency of one basic clock is 10 MHz. 7
Reference numeral 2 denotes a scanner which reads a document image, converts it into an electric signal, and outputs the signal. The scanner 72 is provided inside the upper surface of the rear portion of the main body as described above. The light source for irradiating the original with the scanner 72 is an LED, and its reading resolution is 200 dpi. By combining the scanner 72 and the scanner controller 73, image data read by the scanner 72 can be processed by a binary or error diffusion method and input to the CPU 71. The scanner controller 73 performs mechanical control and driving of the entire scanner 72 and performs image reading such as binary / halftone (error diffusion method). The printer M9 is provided separately in this embodiment, and is an ink-jet printer using thermal energy as described above, but the present invention is not limited to this.

Inside the host M1, a resolution of 200
Although an image of dpi is processed, since image conversion and recording control of the printer are performed by the printer controller 74 described below, the image data having a resolution of 200 dpi must be printed using a printer having a resolution of 360 dpi. Can be. That is, the printer controller 74 converts the image data input from the I / O controller 75 into a parallel signal, and outputs the parallel signal to the printer M9 through the printer interface. I / O controller 7
5 controls the standard I / O other than the memory. That is, an address, data, and control information are inputted from the CPU 71, and these are input to a floppy disk (not shown), a controller (not shown), a real-time clock (not shown), a hard disk controller (not shown), a telephone, a facsimile apparatus, a sound source controller ( (Not shown) or the like, performs 8-bit / 16-bit bus conversion and address decoding. Further, it also performs bus control (DMA control and the like) for transferring data to the scanner controller 73, the printer M9, and the printer controller 74.

FIG. 1 is a flowchart showing a printer control process in the printer controller 74. The printer controller 74 includes an I / O controller 75
Image data with a resolution of 200 dpi sent from an inkjet printer M having a resolution of 360 dpi
In order to output high-quality images, various image data conversion processes and the like are performed.

An outline of this processing will be described. When the resolution of print data (image data) is 360 dpi, which is the same as the resolution of the printer M9, only vertical / horizontal conversion is performed to match the print data with the print order by the print head 17. Is good. However, if the resolution of the print data is different from the resolution of the printer M9, for example, 200 dpi, the print data is temporarily expanded and converted to a resolution of 400 dpi, and at this time, the height of the print image accompanying the resolution correction in the sub-scanning direction is performed later. In order to correct the density, the density correction and smoothing processing of the recording data are performed. Next, resolution correction for converting the resolution of the printer M9 in the main scanning direction to 360 dpi, and further,
A vertical / horizontal conversion of recording data for performing an image arrangement for matching the arrangement of 4 dots is performed. Further, in order to convert the resolution in the sub-scanning direction of the printer M9 to 400 dpi, the rotation speed of the carriage motor 31 for scanning the recording head 17 in the S direction is controlled. FIG. 1 is a flowchart showing these processes.

First, in step S1, when resolution data of the recording data is sent together with the recording data from the I / O controller 75, the resolution is determined. That is, here, the recording data has a resolution of 200 dpi.
Facsimile received image data or resolution is 360 dp
It is determined whether the document data is document data of the word processor i. If the resolution is facsimile reception image data of 200 dpi, the process proceeds to step S3. In order to output this image data to a printer of 360 dpi, the resolution in the S direction (sub-scanning direction) is 400 dpi and the resolution in the N direction (main scanning direction) is A resolution extension conversion for setting the resolution to 360 dpi is performed. At this time, density correction is further performed in order to correct higher density of the recorded image accompanying resolution correction in the subsequent sub-scanning direction. Next, the process proceeds to step S4, in which the resolution-converted print data is subjected to vertical / horizontal conversion.

On the other hand, in the case of word processing document data having a resolution of 360 dpi, no resolution conversion is necessary, so the process proceeds to step S2, and similarly to step S4, 360 dpi.
Only the vertical / horizontal conversion of the image data of 360 dpi is performed.

Next, proceeding to step S6, the print data converted in step S2 or steps S3 to S5 generates a print command adapted to each, and is transferred to the printer M9 together with the print command (step S6).
7).

Next, the details of the image data conversion processing method shown in steps S3 to S5 in the flowchart of FIG. 1 will be described.

The resolution in the sub-scan (S direction) is 200 dp
i, input image data having a main scanning (N direction) resolution of 200 dpi is output to a 360 × 360 dpi printer M9. First, the resolution in the S direction is set to 400 dpi.
The resolution in the N direction is converted to 360 dpi. In this resolution conversion processing, the resolution in the S direction is set to 400 dpi, and in the sub-scanning direction (S direction) resolution correction performed in step S5, the rotation speed of the carriage motor 31 is set to 360/400 (9/10) at the time of 360 dpi recording. The image is recorded with the image resolution in the sub-scanning direction set to 400 dpi by recording at a variable speed (this will be described later in detail). As a result, there is an advantage that information is not lost due to dot thinning in the sub-scanning direction and image distortion does not occur, but the dot density in the sub-scanning direction is (400/360) times the dot density in the main scanning direction. Therefore, there is a disadvantage that the density of the output image is increased. Therefore, as described above, in the process of step S3,
Density correction is being performed. Next, the density correction will be described.

FIG. 8 shows resolutions of 360 dpi and 400 dpi.
FIG. 6 is a diagram showing a relationship between recording dots recorded by i.

FIG. 8A shows the case where the resolution is 1 at 360 dpi.
FIG. 8B shows a case where dots are arranged every other dot at a resolution of 400 dpi. Here, since the recording area per dot is the same in each case,
In the case of (b), the dot interval is smaller, and the ratio of dots in a predetermined recording area is larger. The dots recorded by the inkjet printer are recorded by ejecting ink droplets, and thus each dot has a circular shape. As shown in FIG. 8C, this is about 1.5 times the actual expected recording area S, and there is a slight increase in the recording area ratio even in normal recording with a resolution of 360 dpi.

As a result, the entire recorded image becomes dark, which is a serious problem particularly when recording an image in the sub-scanning direction at a resolution of 400 dpi. Therefore, in order to correct such an increase in the density of the recorded image,
In step S3, the resolution in the S direction is set to 400 dpi.
In the process of converting the resolution in the N direction to 360 dpi,
At the same time, density correction by dot operation is performed.

FIG. 9 shows that the resolution of the recording data in the main scanning direction (N direction) is 360 dpi and the sub scanning direction (S direction).
FIG. 7 is a diagram for explaining a conversion method when converting the resolution of the image into 400 dpi. Here, the resolution is 200 dpi
The density correction by the dot operation which is performed simultaneously when the resolution is converted to 360 dpi is not shown.

FIG. 9A shows image data having a resolution of 200 dpi, and is represented by dots arranged in the vertical direction (N direction) from the first line to the tenth line. The number "1" assigned to each dot represents a dot on the first line, "2" represents a dot on the second line, and so on, and "10" represents a dot on the tenth line. . The dot row in the N direction is converted to a resolution of 360.
FIG. 9B shows a state where the image data is converted into dpi image data.

In FIG. 9B, the dots "1" on the first line are four "1a", "1b", "1c", and "1d".
Similarly, the dot “2” has four dots “2a” to “2d”, and the dots “3” to “4” and “6” to “9” have one dot of four dots. Has been converted to. Then, each of the dots “5” and “10” is “5”.
a "," 5b "and two dots" 10a "and" 10b ". As a result, as shown in FIG. 9, the dots" 1 "to" 10 "of the image data having a resolution of 200 dpi are obtained. 10 dots are 1.8 times 18 in the N direction (main scanning direction).
It is enlarged to dots (360 dpi) and doubled in the S direction
This means that the resolution has been converted to dots (400 dpi). Therefore, the resolution R _N after conversion of the N-direction, also 25.4 / 200 × 10 = 25.4 / R N × 18 ∴R N = 360 (dpi), the resolution R _S after conversion S direction, 25.4 / 200 × 1 = 25.4 / R S × 2 ∴R S = 400 (dpi) , and this conversion is performed to the extent that the presence of the image data with the S-direction and the direction N, eventually A4 Size 20
The image data of 0 × 200 dpi is 400 × 360 dpi.
It is converted to i image data.

Next, the density correction performed simultaneously with the resolution conversion will be described.

A case where one dot is converted into four dots, such as dots "1" to "4" and "6" to "9" in FIG. A case where one dot is converted into two dots, such as dots “5” and “10”, is called a 1-2 conversion pattern.

FIG. 10 is a block diagram of a processing unit for performing the above-described resolution conversion and density correction (processing in step S3).
Although this processing unit is provided in the printer controller 74 in the present embodiment, it is a matter of course that the processing unit may be provided in the printer controller 65 in the printer M9.

Reference numeral 67 denotes a line buffer constituted by, for example, a dynamic RAM, which can store image data 91 inputted from the CPU 71 for three lines.
Reference numeral 68 denotes a 3 × 3 matrix extraction unit,
7 of the bit image 92 input from the
3 × 3 composed of a total of 9 pixels consisting of 8 pixels around _{i and j}
Pixels are extracted. Reference numeral 69 denotes an image processing unit that processes the image 93 extracted by the 3 × 3 matrix extraction unit 68 to create recording pixels 95. Reference numeral 70 denotes a buffer which can temporarily store print data and output 64 lines of image data (print data) in order to output the print pixels 95 processed by the image processing unit 69 to a printer.

Now, when the A4 size image data 91 is sent to the line buffer 67, the image data stored in the line buffer 67 is cut out by the 3 × 3 matrix extraction unit 68 by 9 pixels, and is sent to the image processing unit 69. Is output. The image processing unit 69 converts the resolution of 9 pixels of data and performs density correction processing to determine the center pixel (x _{i, j} ) of the 3 × 3 matrix as 4 dots or 4 dots as described above with reference to FIG. This is converted into a recording pixel of 2 dots (a multiple pixel of 5). By sequentially performing this operation, all the A4 size image data is converted.

FIG. 11 is a flowchart showing an image conversion process in the image processing section 69. The input 3 × 3 matrix image data is processed according to this flowchart to generate a recorded image.

First, according to the pixel array of the 3 × 3 pixel matrix, that is, the eight patterns shown in FIG. FIG. 12B shows a 1-4 conversion pattern, and FIG. 12C shows a 1-2 conversion pattern.

As shown in FIG. 12A, a 3 × 3 mat
9 pixels x extracted as ricks_{i- 1, j-1} ・ X_{i, j-1} ・
x_{i + 1, j-1} ・ X_{i-1, j} ・ X_{i, j} ・ X_{i + 1, j} ・ X_{i-1, j + 1} 
・ X _{i, j + 1} ・ X_{i + 1, j + 1} Depends on the pixel arrangement
Are classified into patterns. In these ~ patterns
Accordingly, the target pixel x_{i, j} X in the 1-4 conversion pattern
_ij1 ~ X_ij4 Up to four pixels (FIG. 12B)
X in the conversion pattern_{ij 1} , X_ij2 12 pixels (FIG. 12
(C)). Here, in FIG.
In a 3 × 3 pixel matrix that is a pattern of
“□” indicates a white pixel before conversion, and “■” indicates a black pixel before conversion.
And “□” with “x” is white before conversion
Or black pixels.

Further, “□” in FIGS. 12B and 12C
Indicates a white pixel after conversion, and “■” indicates a black pixel after conversion. For example, in the 1-4 conversion pattern of FIG. 12B, when the 3 × 3 matrix pattern is a pattern in which black pixels are arranged in an obliquely upper right direction, the _target pixel x _ij is represented in FIG. As shown by the conversion pattern 111, a recording pixel is composed of three dots x _ij2 , x _ij3 , and x _ij4 . Therefore, not only the connection between the two pixels x _{i + 1, j-1} and x _{i-1, j + 1} is not broken, but also the slanted line has a sharp corner and becomes a smooth line. In the same manner, in the pattern (1) to (4), since the operation of extracting the recording pixel on the white pixel side instead of the adjacent black pixel side is performed, the recording and the smoothing of the line are performed while maintaining the connection between the pixels. Can be played. Further, in the case of a pattern other than 〜, the target pixel x _{i, j} is simply multiplied by 2 × 2, so that even in the case of black on one side, no image deterioration due to missing dots occurs.

Since such density correction processing is performed by patterning the processing of oblique lines as described above,
It also has a smoothing effect to convert to less jagged characters and figures. Thereby, not only is the pre-conversion image data having a resolution of 200 dpi converted to image data adapted to a dot density of 360 dpi but is also converted to high-resolution image data having a resolution of 360 dpi. Fine, high-quality images will be recorded.

The image data having the resolution converted as described above and having a resolution of 400 dpi × 360 dpi is transferred in blocks of 64 dots in the N direction in accordance with the serial recording output of the ink jet printer M9. Done.

FIGS. 13A and 13B are diagrams for explaining such vertical / horizontal conversion.

As shown in FIG. 13A, recording data converted to a resolution of 400.times.360
The dots are sequentially arranged in the S direction, such as 3,... N−1, n, and are stored in the line buffer 70 for 64 lines. This recording data is transferred to the printer M9 in units of blocks from the first block to the n-th block, as shown in FIG. 13B, with 64 dots in the N direction as one block. At this time, the recording data of 64 dots constituting each block is divided into 8 dots each, and is transmitted as recording data of 1 byte each, in order of 8 bytes, as recording data of a total of 64 dots (for the nozzle of the recording head 17). Have been.

In the case of a word processing document image having a resolution of 360.times.360 dpi, a vertical / horizontal conversion process is similarly performed and transferred to the printer M9. In this way, the image data that has been vertically and horizontally converted and transferred in block units of 64 dots is recorded by the printer M9.

Next, a method of recording at a resolution of 400 dpi in the sub-scanning direction (S direction) will be described with reference to FIG.

FIG. 14 shows the recording head 17 of the printer M9.
FIG. 5 is a diagram showing a relationship between an ejection pulse for ejecting ink droplets from the nozzles and a drive pulse for driving the carriage motor 31.

(A) shows an ejection pulse of an ink droplet ejected from the recording head 17 in synchronization with the scanning of the carriage 11 in the S direction. For one pulse of this ejection pulse,
One ink droplet is ejected, and an image of one dot is formed on the recording paper surface. The frequency of this ejection pulse is 3 KHz,
3000 dots can be recorded in one second. FIG.
4B shows the drive pulses of the carriage motor 31 when printing at a resolution of 360 dpi, and the carriage 11 (recording head 17) is driven by 0.71 at each pulse.
mm. Between each of these pulses, the ejection pulse is 1
Since 0 pulses are output, an image (pixel) of 10 dots can be recorded within a recording length of 0.71 mm. The driving speed of the carriage motor 31 at this time is 300
pps.

FIG. 14C shows the driving pulses of the carriage motor 31 when the carriage 11 is scanned in the S direction to record image data having a resolution of 400 dpi. Here, in order to correspond to a resolution of 400 dpi, 11 dots must be recorded while the carriage 11 moves by 0.71 mm. Here, since the cycle of the ejection pulse for ejecting ink from the recording head 17 is constant at 3 KHz, the driving pulse of the carriage motor 31 is changed to 273 pps to reduce the scanning speed of the recording head 17 and to reduce the scanning speed for the predetermined recording length. The density of recording dots is increased.

FIG. 15 shows a recording example in which recording is performed by performing the density correction processing as described above.

FIG. 15A shows a recorded image having a resolution of 200 dpi recorded based on the image data before the density correction, and FIG. 15B shows the resolution after the density correction. Indicates a recorded image of 400 × 360 dpi. Note that FIG. 15B is an example of recording by an ink jet printer, and thus the recorded dots are circular in shape.

In the present embodiment, the printer M9 is described as an ink jet printer, but the present invention is not limited to this, and the recording method is not particularly limited as long as it is a serial printer. Also, the printer M
Reference numeral 9 denotes a separate type connected via an interface cable, but may be an integrated type.

In this embodiment, the image data to be processed is described as a received image of a facsimile of 200 dpi and a document image of a resolution of 360 dpi. However, the types and resolutions of these image data are not limited to this embodiment. Not something.

The conversion pattern for density correction shown in FIG. 12 is not limited to this embodiment, and an optimum pattern may be created or selected according to the characteristics of the printer used, the resolution to be converted, and the like. .

The present invention may be applied to a system constituted by a plurality of devices or to an apparatus constituted by a single device. Needless to say, the present invention can also be applied to a case where the present invention is achieved by supplying a program for implementing the present invention to a system or an apparatus.

As described above, according to the present embodiment, when recording low-resolution image data using a high-resolution printer, the resolution of the image data is converted, and at that time, conversion is performed according to the situation of peripheral pixels. By determining the arrangement of pixels, a high-quality image without image distortion can be recorded.

Also, by changing the scanning speed of the recording head for recording to change the resolution, the original image data can be converted without thinning out, and the uniform interpolation operation can be performed. Smooth, high-resolution image recording without distortion is possible.

[0077]

As described above, according to the present invention, for image data having a resolution different from the predetermined resolution of the printer, the resolution of the image data which is close to the predetermined resolution and which does not require the thinning of the image data is required. By converting the image data into the image data and recording it, there is an effect that the resolution of the image data can be easily converted and a high-quality image can be recorded.

Also, by determining the arrangement of pixels to be interpolated for resolution conversion by judging from the state of the peripheral pixels of the original recording data, for example, jaggies generated in image distortion or oblique lines of the image can be obtained. There is an effect that can be reduced.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating image data conversion processing in a printer controller according to an embodiment.

FIG. 2 is an exploded perspective view showing an internal configuration of the printer of the embodiment.

FIG. 3 is a block diagram illustrating a schematic configuration of a printer according to the embodiment.

FIG. 4 is an external perspective view of an ink cartridge of a recording head in the printer according to the embodiment.

FIG. 5 is a diagram illustrating a nozzle arrangement example of a recording head in the printer according to the embodiment.

FIG. 6 is a block diagram illustrating a schematic configuration of a host according to the present embodiment.

FIG. 7 is an external perspective view illustrating an example of a system using the device according to the present embodiment.

FIG. 8 is a diagram illustrating a relationship between dots printed at resolutions of 360 dpi and 400 dpi and a dot shape.

FIG. 9 is a diagram for explaining a conversion method when converting the resolution of print data.

FIG. 10 is a block diagram illustrating a configuration of a processing unit that performs resolution conversion and density correction shown in step S3 of FIG.

11 is a flowchart illustrating a density conversion process in the correction unit in FIG.

12 is a diagram illustrating an example of a pattern for determining the arrangement of recording dots in the correction unit in FIG. 10;

FIG. 13 is a view for explaining a vertical / horizontal conversion process of rearranging print data in accordance with a nozzle row of a print head of the printer of the embodiment.

FIG. 14 is a diagram illustrating a relationship between an ejection pulse for ejecting an ink droplet from a nozzle of a recording head of a printer and a driving pulse for driving a carriage motor.

FIG. 15 is a diagram illustrating a recording example of a printer device of the system according to the present embodiment.

FIG. 16 is a diagram for explaining a conventional resolution conversion method.

FIG. 17 is a diagram for explaining a recorded image recorded using a conventional technique.

[Explanation of symbols]

 M1 Host M9 Printer 9 Ink cartridge 11 Carriage 17 Recording head 31 Carriage motor 65, 74 Printer controller 67 3 line buffer 68 3 × 3 matrix extraction unit 69 Image processing unit 70 64 line buffer

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI H04N 1/413 B41J 3/12 G 3/10 101T (72) Inventor Osamu Yamada Canon Inc. 3- 30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Soji Hamano 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (56) References JP-A-63-252751 (JP, A) JP-A-2-198876 (JP, A (58) Fields surveyed (Int.Cl. ⁶ , DB name) B41J 2/51 B41J 2/485 G09G 5/26 G09G 5/28 610 H04N 1/387 101 H04N 1/413

Claims (6)

(57) [Claims] 1. A printer control device for controlling a printer that scans a recording head and records an image on a recording medium at a predetermined resolution based on image data, wherein the image is obtained by changing a scanning speed of the recording head. Recording control means capable of recording data at a resolution different from the predetermined resolution, and when the resolution of the input image data is different from the predetermined resolution, the resolution of the image data is close to the predetermined resolution, and Converting means for converting the image data into image data having a resolution that can be converted without requiring thinning of the image data, wherein the recording control means performs the recording at a scanning speed corresponding to the resolution of the image data converted by the converting means. A printer control unit that scans a head and records the image data whose resolution has been converted by the conversion unit. apparatus. 2. The apparatus according to claim 1, wherein said converting means converts the resolution of the input image data to a resolution close to the predetermined resolution and an integral multiple of the resolution of the input image data. Printer control device as described. 3. The printer control according to claim 1, wherein the conversion unit determines a pixel arrangement of the image data after resolution conversion based on a pixel arrangement near a target pixel of the input image data. apparatus. 4. The apparatus according to claim 1, wherein said conversion means performs density correction of the image data after the resolution conversion based on a resolution of the image data after the resolution conversion and the predetermined resolution. Printer control device. 5. The printer control device according to claim 1, wherein the recording head discharges ink. 6. The recording head is provided for each of a plurality of ejection ports for ejecting ink and a corresponding ejection port, and causes a state change due to heat in the ink to cause the ink to flow from the ejection port based on the state change. 6. The printer control device according to claim 5, further comprising: a thermal energy generating unit configured to discharge and form flying droplets.