JP2001001570A - Printer, method for printing, image processing device, method for image processing and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for quickly printing a high quality image even using a printer not having a memory with a large capacity or a high speed CPU. SOLUTION: In an image processing device for supplying image data to a printer, following image processes are executed. After a printing resolution of the printer, the number of nozzles of a print head and a nozzle pitch are obtained, the image is converted to be in a data format represented by the presence or absence of dots. Next, a forming order of the dots at a time when the dots are formed by plural dots by moving the print head for scanning in a main scanning direction is judged based on the information of the obtained number of nozzles and nozzle pitch by each dot, then the data is supplied to the printer along the order of the dots to be formed in accordance with the judged result. As a result, the printer only forms dots under the order that the printer receives the data so that an operation in the printer can be simplified. Also, it is possible to immediately print a high quality image even by a printer not having a memory with a large capacity or a high speed CPU.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a technique for printing an image by forming dots on a print medium.

[0002]

2. Description of the Related Art A printing apparatus for printing an image by forming dots on a print medium is widely used as an output apparatus of various image devices such as a computer. Such printing devices are:
A plurality of dot forming elements for forming dots on a printing medium are provided, and an image is printed as follows while changing the relative position between the dot forming elements and the printing medium. First, a dot is formed while moving a dot forming element in one direction on a print medium, and a raster as a row of dots is formed on the print medium. When the dot forming element is moved to the edge of the print medium, the print medium is slightly fed in a direction intersecting the moving direction of the dot forming element, and a raster is formed again at a new position on the print medium. Thus, the relative position between the dot forming element and the print medium is determined by the raster forming direction (main scanning direction).
The image is printed by forming rasters one after another on the print medium while moving in the direction (sub-scanning direction) intersecting with the raster direction.

As described above, a printing apparatus prints an image by forming a raster line of dots on a print medium, but an original image to be printed is not usually represented by the presence or absence of dots. That is, since the original image is generally expressed in multiple gradations, image processing for converting the original image into an expression based on the presence or absence of dots is required. Therefore, prior to printing, the image processing apparatus converts the original image into an expression based on the presence or absence of dots, and then supplies the converted image data to the printing apparatus to print the image.

Such image processing is not performed on the entire original image at once, but is performed sequentially from the end of the original image in the raster direction. In other words, a large memory is required for image processing, and a very large memory capacity and image processing time are required for image processing of the entire original image at one time. And sequentially outputting the converted data to the printing apparatus. Thus, when the image processing device converts the original image into an expression based on the presence or absence of dots,
The converted image data is sequentially output to the printing device in raster units.

When image data is sent in raster units, the printing device temporarily stores the image data in an intermediate buffer and forms dots for several rasters collectively. The printing apparatus forms a plurality of rasters corresponding to the number of dot forming elements at the same time by forming dots for each dot forming element while main scanning the dot forming elements. That is, while the image processing apparatus supplies data to the printing apparatus in raster units, the printing apparatus simultaneously forms each raster,
The dots are not formed in the order of the supplied data. For this reason, the printing apparatus temporarily stores the dot data sent from the image processing apparatus in the memory, and when data for several rasters is stored, the data of each raster is transferred to a dot forming element that forms the raster. The processing for supplying the raster little by little from the head position is performed. In this processing, dot data input in raster order is read out in the order in which dots for several rasters are formed, that is, in the order of dots arranged in a direction intersecting with the raster (row direction), and read out as dot forming elements. Since this is output processing, it is also called raster-row conversion.

Since the number of rasters that can be formed in one main scan is determined by the number of dot forming elements provided in the printing apparatus, how many rasters are converted by raster-row conversion is determined by the printing apparatus. It depends on the model. In addition, due to manufacturing problems of each dot forming element, rasters formed at the same time are formed at intervals of several rasters,
The interval between the rasters also depends on the type of the printing apparatus, and if the interval between the rasters is different, the number of rasters to be converted by the raster-row conversion also differs. Furthermore, in a printing apparatus that performs so-called bidirectional printing in which dots are formed bidirectionally in the forward and backward movements of the main scanning, the order in which data is supplied to the dot forming elements in the forward movement and the backward movement is determined. Since it is necessary to reverse the order, the order of data output by raster-row conversion differs depending on whether bidirectional printing is performed or not. As described above, the specific processing content of the raster-row conversion often differs depending on the model of the printing apparatus and the printing method. Therefore,
It is common practice to incorporate a CPU and memory in a printing apparatus, perform raster-row conversion in the printing apparatus on dot data in raster units supplied from an image processing apparatus, and supply the resulting data to dot forming elements. .

[0007]

However, the number of dot forming elements provided in a printing apparatus tends to increase in order to increase the printing image quality and increase the printing speed. High capacity memory and fast processing speed C
Unless a PU is incorporated, there is a problem that the printing speed is reduced. The incorporation of these expensive components increases the manufacturing cost of the printing device. On the other hand, unless a large-capacity memory or a high-speed CPU is used, it takes time to perform raster-row conversion, and it is difficult to realize rapid printing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and enables a high-quality image to be printed quickly without incorporating a large-capacity memory or a CPU capable of high-speed processing in a printing apparatus. It aims to provide technology.

[0009]

Means for Solving the Problems and Their Functions and Effects In order to solve at least part of the above-mentioned problems, the printing apparatus of the present invention employs the following configuration. That is, a printing apparatus that receives image data in a data format represented by the presence or absence of dots, and prints an image by forming dots on a print medium in accordance with the image data. The dot forming element of
A print head formed by arranging dots formed at intervals of one or more dots from each other, print head moving means for moving the print head relative to the print medium, and the print head Image data receiving means for receiving the image data sent in the order of forming a plurality of dots by the plurality of dot forming elements; and, in synchronization with the movement of the print head, the dots are formed in accordance with the received image data. And dot forming control means for controlling the formation of the image.

A printing method according to the present invention corresponding to the above-described printing apparatus receives an image data in a data format expressed by the presence or absence of dots and prints an image by forming dots on a print medium in accordance with the image data. A printing head that forms a plurality of dots on the print medium at a distance of one or more dots from each other, relative to the print medium, and the print head generates a plurality of dots. Receiving the image data sent in the order in which they are formed, and controlling the dot formation of the print head according to the received image data to print an image while synchronizing with the movement of the print head. Make a summary.

In this printing apparatus and printing method, the print head receives dot data sent in the order in which a plurality of dots are simultaneously formed, and the data is sent while synchronizing with the movement of the print head. Dots are formed in order. Therefore, the printing apparatus does not need to perform the raster-row conversion processing of rearranging the received image data in the order in which the print head forms dots, and the large-capacity large-capacity data required for quickly performing the raster-row conversion is eliminated. Even if a printing device not provided with a memory or a CPU capable of high-speed processing is used, rapid printing can be performed.

When the printing apparatus prints an image by forming dots while performing main scanning and sub-scanning of the print head, the image data is sent together with the image data sent in the order of forming dots. The number of dots formed by the print head in the main scanning direction and the amount of movement in the sub scanning direction may be received. Here, the main scanning direction is a direction crossing the direction in which the plurality of dot forming elements are arranged, and the sub-scanning direction is a direction crossing the main scanning direction.

Such a printing apparatus receives the number of dots formed in the main scanning direction and the moving amount in the sub-scanning direction in addition to the image data expressed by the presence or absence of the dots, and receives the data while the printing head performs main scanning. After forming the specified number of dots, the print head is sub-scanned by the received sub-scan amount. In this case, it is possible to easily perform the control of causing the print head to perform main scanning and sub scanning while forming dots.

An image processing apparatus of the present invention for supplying image data to the above-described printing apparatus receives image data, converts the image into a data format represented by the presence or absence of dots, and converts the converted image into a data format. An image processing device that outputs data to a printing device that prints an image while changing a relative position between a print head that forms dots on a print medium and the print medium, wherein the print head can form dots at a time. Dot forming information as information on the number and interval of the dots, and printing condition obtaining means for obtaining a printing resolution as an index indicating the number of dots that can be formed by the printing apparatus per unit area; and Data conversion means for converting the image data into a data format represented by the presence or absence of dots based on the image data, and the print head changes a relative position with respect to the print medium. A dot formation order determining means for determining a formation order of the plurality of dots formed based on the acquired dot formation information, and converting the converted image data according to the determined dot formation order. The gist of the invention is to provide a data output unit for outputting to a printing apparatus.

An image processing method according to the present invention corresponding to the image processing apparatus described above receives image data, converts the image into a data format represented by the presence or absence of dots, and converts the converted image data. An image processing method for outputting an image to a printing apparatus that prints an image while changing a relative position between a print head that forms dots on a print medium and the print medium, the number of dots that the print head can form at one time, The dot forming information as information on the interval between the dots and the print resolution which is an index indicating the number of dots that can be formed by the printing apparatus per unit area are obtained, and the data of the image is obtained based on the obtained print resolution. Is converted into a data format represented by the presence or absence of dots, and the print head forms a plurality of dots while changing the relative position with respect to the print medium. The judges based on the acquired dot forming information, the converted image data, and summarized in that the output to the printing apparatus in accordance with the order of forming the determined dot.

The image processing apparatus and the image processing method convert the image data into a data format expressed by the presence or absence of dots in accordance with the printing resolution of the printing apparatus, and output the converted image data to the printing apparatus. Based on the dot formation information obtained in advance, the print head of the printing apparatus determines the formation order of dots to be formed a plurality of times later while changing the relative position with respect to the print medium, and the determined Output to the printing device according to the dot formation order.

Here, the print resolution and dot formation information may be obtained by, for example, inputting numerical values to the image processing apparatus, or these numerical values may be stored in the image processing apparatus in advance for each printing model. Then, when the model is input to the printing apparatus with respect to the image processing apparatus, the image processing apparatus may read and acquire the print resolution and dot formation information stored in advance.

As described above, the image processing apparatus of the present invention outputs data in accordance with the order in which the print head of the printing apparatus forms dots. Raster-to-row conversion processing for rearranging the data is unnecessary. Therefore, the raster
Even a printing apparatus that does not have a large-capacity memory or a CPU capable of high-speed processing, which is required for performing row conversion quickly, can perform quick printing.

The image processing apparatus further includes information acquisition means for acquiring predetermined information from the printing device.
The information acquisition means may acquire the print resolution and dot formation information of the printing apparatus. For example, the image processing apparatus may communicate with the printing apparatus to acquire data such as print resolution and dot formation information, or store these values in the image processing apparatus for each type of printing apparatus. In advance, the model of the printing apparatus may be identified on the image processing apparatus side, and data such as the corresponding printing resolution may be used.

In this way, it is convenient to save the trouble of inputting the printing resolution of the printing apparatus for outputting the image data and the dot formation information. Also, there is an advantage that there is no possibility that these values are erroneously input to the image processing apparatus. In particular, when a plurality of types of printing apparatuses are used, it is preferable that the printing resolution of the printing apparatus and the dot formation information do not need to be input, because the trouble of inputting and the possibility of erroneous input are eliminated.

If the printing device that supplies the image data is a printing device that prints an image while moving a print head that forms dots relative to a printing medium, the image processing device is converted. In addition to the image data, the number of dots that the print head forms while moving in a certain direction and the amount of movement that moves the print head in a direction that intersects the movement direction after forming the dots of the number of dots are output. May be.

If the number of dots and the amount of movement of the print head are supplied from the image processing apparatus to the printing apparatus in addition to the converted image data, the printing apparatus receives the dot formation and the movement of the print head. Since the control may be performed in accordance with the data, the control load on the printing apparatus can be greatly reduced. For this reason, a large-capacity memory and a C capable of high-speed processing are used.
Even if a printing device that does not include a PU or the like is used, quick printing can be performed.

The present invention can also be realized by taking image data into a computer, applying predetermined image processing to the taken image data using the functions of the computer, and outputting the image data of the image processing to a printing apparatus. It is possible to realize. Therefore, the present invention includes an embodiment as a recording medium in which a program for realizing the image processing method is recorded so as to be readable by a computer. That is, the recording medium of the present invention is provided with a print head that receives image data, converts the image into a data format expressed by the presence or absence of dots, and converts the converted image data into dots on a print medium. A computer-readable recording medium that implements an image processing method for outputting an image to a printing apparatus that prints an image while changing a relative position with respect to a print medium, wherein the print head can be formed at one time. A function of acquiring dot formation information, which is information on the number of dots and the interval between the dots, and a print resolution, which is an index indicating the number of dots that can be formed by the printing apparatus per unit area, based on the acquired print resolution A function of converting the image data into a data format represented by the presence or absence of dots, and the print head changes a relative position with respect to the print medium. A function of determining a dot formation order based on the acquired dot formation information, and outputting the converted image data to the printing apparatus in accordance with the determined dot formation order. The function and function to be performed are recorded.

The computer reads a program for realizing such a function, converts the image data into a data format expressed by the presence or absence of dots, and converts the converted data in the order in which the print head forms dots. If output, printing can be performed quickly even in a printing apparatus that does not have a large-capacity memory or a CPU capable of high-speed processing.

[0025]

DETAILED DESCRIPTION OF THE INVENTION Device Configuration: An embodiment of the present invention will be described based on an example. FIG. 1 is an explanatory diagram showing the configuration of a printing system as an embodiment of the present invention. As shown in the drawing, the printing system has a color printer 20 connected to a computer 80, and a predetermined program is loaded and executed on the computer 80 to function as a printing system as a whole. The color original to be printed is
For example, an image or the like captured by using the color scanner 21 connected to the computer 0 or created by various application programs 91 on the computer 80 is used. The data ORG of these images is stored in a computer 80
Is converted into image data that can be printed by the color printer 20 and output to the color printer 20 as image data FNL. The color printer 20
As a result of forming ink dots of each color on a print medium in accordance with the image data FNL after the image processing, a color image corresponding to a color original is printed on printing paper. That is, the computer 80 functions as an image processing device that receives image data and converts it into a data format that can be printed by the color printer 20, and the color printer 20 functions as a printing device that prints image data that has undergone image processing.

The computer 80 includes a CPU 81 for executing various arithmetic processing and a RAM for temporarily storing data.
83, a ROM 82 for storing various programs, a hard disk 26 and the like. Also, SIO
By connecting 88 to the public telephone line PNT via the modem 24, it becomes possible to download necessary data and programs from the server SV on the external network to the hard disk 26.

The color printer 20 is a printer capable of printing a color image. In the present embodiment, a color image is formed by forming dots of a total of four colors of cyan, magenta, yellow and black on printing paper. You are using an inkjet printer to print. The ink ejection method of the ink jet printer used in this embodiment employs a method using a piezo element PE as described later, but it is also possible to use a printer having a nozzle unit for ejecting ink by another method. Good. For example, the present invention may be applied to a printer of a system in which a heater arranged in an ink passage is energized and ink is ejected by bubbles generated in the ink passage.

FIG. 2 is a block diagram conceptually showing a software configuration of a computer 80 as an image processing apparatus. In the computer 80, all application programs 91 operate under an operating system. A video driver 90 and a printer driver 92 are incorporated in the operating system, and image data output from each application program 91 is output to the color printer 20 via these drivers.

When the application program 91 issues a print command, the printer driver 9 of the computer 80
2 receives image data from the application program 91, performs predetermined image processing, and converts the image data into image data that can be printed by a printer. As conceptually shown in FIG. 2, the image processing performed by the printer driver 92 includes a resolution conversion module 93, a color conversion module 94, a halftone module 95, and an interlace module 9.
6 and a raster-row conversion module 97. Although the contents of the image processing performed by each module will be described later, the image data received by the printer driver 92 is converted by these modules,
After the raster-row conversion is completed, the image data is output to the color printer 20 as final image data FNL. The contents of the raster conversion will be described later. Note that the color printer 20 of this embodiment only plays a role of forming dots in accordance with the image data FNL, and does not perform image processing, but, of course, performs part of image conversion by the color printer 20. There may be.

FIG. 3 shows a schematic configuration of the color printer 20 of the present embodiment. As shown in the figure, the color printer 20 drives a print head 44 to 47 of each color mounted on a carriage 40 to eject ink and form dots. The mechanism includes a mechanism for reciprocating in the axial direction, a mechanism for transporting the printing paper P by the paper feed motor 35, and a control circuit 60.

The mechanism for reciprocating the carriage 40 in the axial direction of the platen 36 includes a sliding shaft 33 that slidably holds the carriage 40 erected in parallel with the axis of the platen 36.
Between the endless drive belt 3 and the carriage motor 30
1 and a position detection sensor 34 for detecting the origin position of the carriage 40.

The mechanism for transporting the printing paper P is a platen 3
6, a paper feed motor 35 for rotating a platen 36,
It comprises a paper feed auxiliary roller (not shown) and a gear train (not shown) for transmitting the rotation of the paper feed motor 35 to the platen 36 and the paper feed auxiliary roller. Printing paper P
Is set so as to be sandwiched between the platen 36 and the paper feed auxiliary roller, and is fed by a predetermined amount according to the rotation angle of the platen 36.

Since the color printer 20 of this embodiment receives image data that has undergone raster-row conversion, a simple circuit centered on a so-called one-chip microcomputer 61 is used as the control circuit 60. That is, a one-chip microcomputer 61 and an RA temporarily storing image data supplied from the computer 80 are provided inside the control circuit 60.
M62 and print heads 44 to 47
A drive buffer 63 for supplying an OFF signal, an oscillator 64 for outputting a drive waveform, and a distribution output device 65 for distributing the output of the oscillator 64 to the print heads 44 to 47 of each color at a predetermined timing are provided.

The one-chip microcomputer 61 outputs a trigger signal to the oscillator 64 while outputting a drive signal to the carriage motor 30, reads out the dot on / off signal stored in the RAM 62, and outputs the dot on / off signal to the drive buffer 63. Output. In this way, under the control of the one-chip microcomputer 61, ink droplets are ejected from the respective nozzles provided in the print heads of the respective colors while performing the main scanning of the carriage 40. The one-chip microcomputer 61 also controls the movement of the paper feed motor 35 in synchronization with the movement of the carriage. As a result, dots can be formed at appropriate positions on the printing paper.

Since the color printer 20 of this embodiment does not perform raster-row conversion, the main functions of the one-chip microcomputer 61 are the carriage motor 30 and the paper feed motor 3.
5, writing dot data in the RAM 62 into the drive buffer 63 while synchronizing with the oscillator 64. Therefore, it is relatively easy to configure the control circuit 60 using a basic logic circuit without using a microcomputer. If the control circuit 60 does not use the one-chip microcomputer 61, the manufacturing cost of the color printer 20 can be further reduced.

The carriage 40 is equipped with an ink cartridge 42 for storing black (K) ink and an ink cartridge 43 for storing a total of three colors of cyan (C), magenta (M) and yellow (Y). ing. Of course, the K ink and the multi-color ink may be stored in the same ink cartridge. If a plurality of inks can be stored in one cartridge, the ink cartridge can be made compact. When the ink cartridges 42 and 43 are mounted on the carriage 40, the respective inks in the cartridges are supplied to the print heads 44 to 47 for the respective colors through introduction pipes (not shown). The ink supplied to each nozzle unit is discharged by a method described below, and forms dots on printing paper.

FIG. 4A is an explanatory diagram showing the internal structure of the print head. The print head of each color is provided with 96 nozzles Nz, and each nozzle has an ink passage 50.
And a piezo element PE is provided on the passage. As is well known, the piezo element PE is an element that distorts the crystal structure due to the application of a voltage and converts electro-mechanical energy very quickly. In the present embodiment, by applying a voltage having a predetermined time width between the electrodes provided at both ends of the piezo element PE, the piezo element PE expands by the voltage application time as shown in FIG. One side wall of the ink passage 50 is deformed. As a result, the volume of the ink passage 50 expands and contracts in accordance with the expansion of the piezo element PE, and the ink corresponding to the contraction is ejected at high speed from the nozzle Nz as particles Ip. When the ink Ip soaks into the printing paper P mounted on the platen 36, dots are formed on the printing paper P. The size of the ejected ink droplet can be controlled by controlling the voltage waveform applied to the piezo element PE. By controlling the size of the ejected ink droplet, it is possible to control the size of the ink dot formed on the printing paper.

The color printer 20 of this embodiment uses an ink jet printer of a type in which ink droplets are ejected by changing the volume of an ink passage by a piezo element PE. It goes without saying that a printer that discharges ink, for example, a printer that generates ink bubbles by using a heater and discharges ink droplets may be used. Further, the method is not limited to the method of forming dots by ejecting ink droplets, but may be a method of forming dots by another method such as a thermal transfer method.

FIG. 5 is an explanatory diagram showing a state in which the ink discharge nozzles Nz are arranged in the print heads 44 to 47. As shown in FIG.
Six nozzles are arranged at a constant nozzle pitch k. The nozzles may be arranged in a staggered manner. If the nozzles are arranged in a staggered manner, there is an advantage that the nozzle pitch k can be easily set small in manufacturing.

As shown in FIG. 5, the print heads 44 of each color
Numerals 47 are arranged with their positions shifted in the transport direction of the carriage 40. Control circuit 60 of color printer 20
Drives the respective nozzle units at an appropriate timing while discharging the ink droplets while considering the difference in the nozzle positions while transporting the carriage 40.

Next, the control circuit 60 of the color printer 20
The one-chip microcomputer 61 built in the
By outputting the dot on / off signal to 3,
A mechanism for ejecting ink droplets will be described. FIG. 6A is an explanatory diagram showing the connection of one nozzle row of the print heads 44 to 47 as an example. FIG.
As shown in (a), the nozzle arrays of the print heads 44 to 47 are interposed between the distribution output device 65 as a source and a ground (GND) at a sink, and an output terminal of the drive buffer 63. Are connected to the print heads 44 to 47. When a dot on / off signal is written to the drive buffer 63, this signal is supplied to the print head,
Ink droplets are ejected from the nozzles to which the ON signal is supplied to form dots on the print medium.

FIG. 6B is an explanatory diagram conceptually showing the electrical connection between the drive buffer 63, the print heads 44 to 47, and the distribution output device 65. As shown in FIG. 6B, the print heads 44 to 47 can be considered by replacing them with a piezo element PE and a switching element. In the circuit thus replaced, it is assumed that the output terminal of the drive buffer 63 is connected to the base terminal B of the switching circuit, the distribution output device 65 is connected to the collector terminal C of the switching circuit, and the ground is connected to the emitter terminal E. be able to. When the dot ON signal of the drive buffer 63 is input, its output terminal becomes a high voltage state, and a drive current flows from the collector terminal C to the emitter terminal E, and the piezo element P
E is driven to eject ink droplets from the nozzles.

With this mechanism, when the one-chip microcomputer 61 incorporated in the color printer 20 outputs the on / off signal of the dot for each nozzle to the drive buffer 63, only the piezo element PE receiving the on signal drives. Is done. As a result, ink droplets are simultaneously ejected from the nozzles of the piezo element PE that have received the ON signal from the drive buffer 63, forming dots on the print medium.

In the color printer 20 having the above-described hardware configuration, the print heads 44 to 47 of each color are moved in the main scanning direction with respect to the printing paper P by driving the carriage motor 30, and the paper feeding is performed. By driving the motor 35, the printing paper P is moved in the sub-scanning direction. Under the control of the control circuit 60, while repeating the main scanning and the sub-scanning of the carriage 40, the color printer 20 prints a color image on a printing paper by driving nozzles at appropriate timings to eject ink droplets. ing.

B. Outline of Image Processing: As described above, the color printer 20 has a function of receiving a supply of image data FNL and printing a color image.
The computer 80 performs predetermined image processing on a color image to generate image data FNL to be supplied to 0. FIG.
The computer 80 transmits the image data F to the color printer 20.
9 is a flowchart illustrating an outline of a process of outputting an NL and printing an image. Such processing is performed by the computer 80
Is realized using the functions of the CPU 81 in the printer driver 92. Hereinafter, the outline of the image processing will be described with reference to FIG.

As shown in FIG. 7, when the image processing is started, the CPU 81 first acquires the printing conditions of the color printer 20 (step S100). The printing conditions of the color printer 20 are conditions such as the printing resolution, the number of nozzles provided in the print head, and the nozzle pitch k. CPU8
1 obtains these conditions of the color printer 20, converts the image data, and rearranges them in the order in which the print head forms dots and supplies them to the color printer 20. Therefore, prior to the start of the image processing, the printing conditions are acquired.

The acquisition of the printing conditions in step S100 is performed by the computer 8 in the color printer 20 of this embodiment.
This is performed by inputting a numerical value from the CRT 23 of 0, but conditions such as the printing resolution, the number of nozzles, and the nozzle pitch are stored in advance for each model of the color printer 20, and
When a model name of the color printer 20 is input from the CRT 23, a value stored in association with the model name may be automatically acquired. The computer 80 communicates with the color printer 20, and the color printer 20
The required data may be obtained from the.

When the printing conditions are obtained, the CPU 81 inputs image data (step S102). This image data is data supplied from the application program 91 as described with reference to FIG. 2. For each of the R, G, and B colors of each pixel constituting the image, 256 gradations of 0 to 255 are set. Data.

When the CPU 81 receives the image data,
Image data F that can be printed by the color printer 20 by performing predetermined image processing such as resolution conversion, color conversion, and multi-value processing.
It is converted to NL (step S104). That is, the resolution of the input image is converted to the printing resolution of the color printer 20 (resolution conversion), and the expression by additive color mixture using RGB is converted into the expression by subtractive color mixture using CMYK. (Color conversion), the image data having 256 gradations is converted into an expression format based on the presence or absence of dots (multi-value processing).

When the image processing is performed to convert the image data into dot data in an expression format based on the presence or absence of a dot, the CPU 81 starts an interlace process (step S106). In the interlace processing,
Based on the data such as the number of nozzles and nosle pitch obtained in step S100, a process of rearranging the raster order is performed as described later. As shown in FIG. 5, since the print head forms dots at the no-nose pitch k, it is impossible to form rasters of consecutive numbers in one main scan. Therefore, in each main scan, while forming a plurality of rasters at an interval of the nozzle pitch k, the forming position is slightly shifted each time a raster is formed, and the space between the rasters is gradually filled with the raster. Finally, a continuous raster is formed. In other words, the order in which the print heads form rasters is different from the order in which the rasters are arranged on the image. Therefore, the image data obtained by image processing is rearranged in raster order in the order in which the print heads form. Processing is required. Such a process is a process called an interlace process.

FIG. 8 is an explanatory diagram conceptually showing a state in which the CPU 81 performs the interlace processing. As a result of the image processing in step S104, as shown in FIG.
Since the raster is developed in a predetermined area (area A) on the AM 83, a raster formed by the print head at one time is selected from the raster and is developed on an area (area B) separately secured on the RAM 83. In FIG. 8, the numbers on the left side of the area A are the serial numbers of the rasters, and each raster stores data indicating the presence or absence of dots. The shaded raster in the area A is the raster selected by the interlace processing. In the example shown in FIG. 8, since the selection is made for every four rasters, this corresponds to the case where the nozzle pitch k of the print head is k = 4. The raster selected in this way is developed in the area B secured on the RAM 83. Since the print head of this embodiment has 96 nozzles for each color, in the interlace processing, the order of 96 rasters is rearranged for each main scan and the raster is developed in the area B.

When the 96 rasters are rearranged as described above, the CPU 81 starts a raster-row conversion process (step S108). As described above, the print head prints an image by performing main scanning on the print medium while discharging ink droplets from the 96 nozzles. Therefore,
In accordance with the main scan of the print head, data on whether or not to form dots should be supplied to each of the 96 nozzles at the same time. In the raster-row conversion process, data on the presence / absence of dots for each raster is read simultaneously from the top of 96 raster data developed in the area B and supplied to the print head of each color. Details of the raster-row conversion processing will be described later.

When the raster-row conversion processing is completed, the CP
U81 outputs the converted image data to the color printer 20 (step S110). Upon receiving the image data, the color printer 20 forms dots of each color on a print medium according to the received image data while performing main scanning of the print head. Thus, a desired image corresponding to the document is obtained on the print medium. Color printer 2
0 means that the print head can be supplied as it is when image data is received, so that raster-row conversion processing is not required, and a large-capacity memory or a CPU capable of high-speed processing can be used.
There is no need to mount

In FIG. 7, for convenience of explanation, the interlace processing is performed on the entire image (step S).
106), raster-row conversion is started (step S10).
8), it has been described as if the converted data were output together to the color printer 20 after the raster-row conversion was completed (step S110). However, as described below, in actuality, each process from the interlace process to the data output process is repeatedly performed in units of 96 rasters, which is the number of rasters formed by the print head in one main scan. .

C. Raster-row conversion processing: The raster-row conversion processing performed in the color printer 20 of the present embodiment will be described. FIG. 9 is a flowchart showing a flow of processing in which the CPU 81 reads data after the interlace processing, performs raster-row conversion, and outputs the converted data. In the color printer 20 of the present embodiment,
The raster-row conversion is not performed independently, but is performed as a part of a series of processes from the interlace process to the data output process. That is, after the image is converted into image data expressed by the presence or absence of dots by the image processing in FIG. 7, the number of raster lines formed by the print head in one main scan (96 in the color printer 20 of this embodiment) , The interlace processing, the raster-row conversion processing, and the data output processing are repeatedly performed. Hereinafter, description will be given according to the flowchart shown in FIG.

Prior to the raster-row conversion, the CPU 81
Performs an interlace process (step S200). That is, from the data after the image processing developed on the RAM 83, data for 96 raster lines that can be simultaneously formed by the print head is selected and developed on a predetermined area B on the RAM 83 (see FIG. 8). FIG. 10A shows a state in which data is expanded on the area B of the RAM 83. As shown in the drawing, 96 raster data corresponding to each of the nozzles No. 1 to No. 96 provided in the print head are developed.

Next, the CPU 81 transfers 2 bytes of data from the head of each raster developed on the area B to the high-speed memory in order to perform raster-row conversion (step S).
202). In the color printer 20 of this embodiment, a static RAM is used as a high-speed memory. In the raster-row conversion, data must be read out in bit units at the same speed as the print head forming dots, and the data is transferred from the area B on the ram 83 to the high-speed memory.

FIG. 10B shows a state where 2-byte data is transferred to the high-speed memory and expanded. 96 data corresponding to nozzles 1 to 96 of the print head are developed. The value of each bit in the 2-byte data shown in FIG. 10B determines whether or not the nozzle forms a dot. For example, bit value "1"
Is supplied to a nozzle, the nozzle ejects an ink droplet to form a dot, and when a bit value “0” is supplied, the nozzle does not form a dot.

When 2-byte data is expanded in the high-speed memory, the data of each expanded bit is read out and written to the intermediate buffer in the order in which the print head forms dots. Specifically, a variable N indicating a bit position is initialized (step S204), and the Nth bit of the 96 data is written to the intermediate buffer (step S20).
6). When the value of the Nth bit of each of the 96 2-byte data is written to the intermediate buffer, the value of the variable N is increased by one (step S208), and it is determined whether or not the variable N is 15 or less (step S210). . The value of variable N is 15
In the following cases, all the bits of 2 bytes have not been written to the intermediate buffer yet, so the flow returns to step S206 to write the data of the next bit to the intermediate buffer (step S206). As described above, raster-row conversion is a process in which the raster data selected by the interlace process is fetched into the high-speed memory every two bytes, and all the fetched data is cut out in bit units and written into the intermediate buffer.

When the value of the variable N representing the bit position becomes 16 in step S210, the raster-row conversion of the 2-byte data expanded in the high-speed memory has been completed, and the raster-row conversion has not been performed yet. Raster data is RA
It is determined whether or not it remains on M83 (step S212). In other words, the raster-row conversion uses the interlaced data developed on the RAM 83 as 2
Since the data is transferred to the high-speed memory byte by byte, when raster-row conversion for 2 bytes is completed, it is determined whether or not unprocessed data still remains. If data remains on the RAM 83 that has not yet been processed,
Data is transferred to the high-speed memory in units of 2 bytes (step S
214), and perform the processing after step S204 to perform raster-row conversion of the transferred data.

As described above, when all 96 interlaced data rasterized on the RAM 83 are raster-row converted, the raster-row converted data written in the intermediate buffer is output to the color printer 20. (Step S216). In the color printer 20 of this embodiment, the raster-row converted data is temporarily written to the intermediate buffer, and the data for one main scan is output to the color printer 20 collectively. The data may be output to the color printer 20. This has the advantage that the storage capacity of the intermediate buffer for temporarily storing the data after raster-row conversion may be small.

In the color printer 20 of the present embodiment, the output of data from the intermediate buffer is performed by serial transfer. That is, data indicating the presence or absence of dot formation is output in the order of the nozzle numbers in a unit of 96 bits, one bit at a time, from the first nozzle to the 96th nozzle provided in the print head.

It is needless to say that data output may be performed by parallel transfer. For example, data representing the presence / absence of dot formation is set to 1 for eight nozzles as one unit.
Parallel output may be performed byte by byte. 9 for print head
Since six nozzles are provided, outputting data of 12 bytes means outputting data of one dot formed by the print head. By performing the parallel transfer in this manner, it is possible to reduce the time for outputting data to the color printer 20.

When all data stored in the intermediate buffer has been output in step S216,
In 200, all 96 raster data developed on the RAM 83 are raster-row converted, and the color printer 2
This means that the value has been output to 0. Then, it is determined whether or not processing of all image data has been completed (step S218). If unprocessed image data remains, step S20 is performed.
0, select 96 raster data again, and
Deploy on M83. That is, the interlacing process is restarted, and a series of processes subsequent to step S202 are executed. Thus, all the image data is transferred to the color printer 20.
Is completed, the process shown in FIG. 9 ends.

D. Dot data processing on the color printer side: the color printer 20 of this embodiment
A process of receiving raster-row converted data from 0 and forming dots will be described. FIG. 11 is an explanatory diagram conceptually showing the flow of dot data in the color printer 20. Data output from the computer 80 is temporarily stored in the RAM 62 and is stored in the one-chip microcomputer 61.
Is transferred to the drive buffer 63.

In the color printer 20 of the present embodiment, since the raster-row converted data is received from the computer 80, the received data can be directly supplied to the print head. Therefore, since the one-chip microcomputer 61 does not require much high-speed processing, an 8-bit CPU is used for the one-chip microcomputer 61 of this embodiment. Since complicated processing is not performed, the processing program is also simplified, and can be stored in the ROM incorporated in the one-chip microcomputer 61. In addition, basic functions of the one-chip microcomputer 61 can be used for functions such as data input / output. A raster 96 is stored in the RAM 62 for each color.
Since the built-in RAM of the one-chip microcomputer 61 has a shortage of capacity because it is necessary to store the image data of the main memory, it is sufficient that the capacity is still about 600 Kbytes.

As described above, the color printer 2 of this embodiment
0 receives the raster-row converted image data from the computer 80 and does not need to perform raster-row conversion on the color printer 20 side. Therefore, it is necessary to incorporate a large-capacity memory and a CPU capable of high-speed processing. Absent. Therefore, even if the memory capacity is reduced or the CPU is changed to one with a lower processing speed, a practically sufficient printing speed can be secured. CPU with reduced memory capacity and slow processing speed
If you change to a cheap one-chip microcomputer,
As a result, the color printer 20 can be manufactured at low cost. Of course, the computer 80 must perform raster-row conversion in addition to image processing. However, in recent years, since a high-performance CPU is mounted on the computer, the computer 80 is required to perform raster-row conversion processing. The load on the CPU does not increase so much, and it is not necessary to change the CPU on the computer side to one capable of higher-speed processing or to increase the memory capacity.

Further, as described above, if the raster-row conversion is performed on the computer side, the processing of the color printer 20 becomes a simple processing. Therefore, it is relatively easy to configure a control circuit without using a CPU. Easy. FIG.
FIG. 3 is an explanatory diagram conceptually showing an example of configuring a control circuit 20 of a color printer 20 without using a PU. An outline of the principle on which the circuit of FIG. 12 operates will be briefly described.

When the computer 80 outputs dot data, it is stored in the RAM 62 via the input interface 66. The address of the RAM 62 for storing data is
The strobe signal output together with the data from the computer 80 is generated by counting by a counter 67 and supplied to the RAM 62 via the multiplexer 68. Further, in the counter 67, in addition to creating the address,
A signal for controlling the operation mode of the RAM 62 is also created. That is, the counter 67 generates a signal whose output is inverted each time the strobe signal is counted and reaches a predetermined value, and the RAM 62 controls whether to read or write data using this signal. RAM 6 stores a predetermined number of data
2, the operation mode of the RAM 62 changes from the write mode to the output mode, and the dot data is output to the drive buffer 63.

The address of the data to be written to the drive buffer 63 is created by using a signal from an encoder provided in the carriage motor. That is, when the carriage 40 is main-scanned, the carriage motor 32 rotates and outputs an encoder signal. Therefore, this signal is counted by the counter 69 to generate an address signal. If the relationship between one pulse of the encoder signal and the rotation angle of the carriage motor 32 is appropriately set, or the frequency of the encoder signal is appropriately divided, a pulse signal synchronized with the timing at which dots are to be formed can be generated. This signal is sent to counter 6
The data is counted by 9 and used as address data. still,
In order to prevent the data write address output from the counter 67 from overlapping with the data read address output from the counter 69, the multiplexer 68
And two different addresses are stored in the RAM 62
Are not supplied at the same time. Counter 69
, A trigger signal is also output to the oscillator 64 at the dot formation timing, and when the trigger signal is received, the oscillator 6
4 outputs a driving waveform of the piezo element, and this waveform is supplied from the distribution output device 65 to each nozzle, and the driving buffer 63
Ink droplets are simultaneously ejected only from the nozzles to which the ON signal is supplied to form dots.

Although only the outline of the operation has been described above, since the color printer 20 of this embodiment does not perform raster-row conversion, the control is simple and the control circuit 60 can be constructed relatively easily without using a CPU. It is also possible. If the control circuit 60 is constituted by a simple circuit as shown in FIG. 12, the manufacturing cost of the color printer 20 can be reduced.

E. Another embodiment: color printer 20
Prints an image while performing main scanning and sub-scanning of the carriage in accordance with dot formation. Therefore, the computer 80 needs to supply the color printer 20 with data on the timing of main scanning of the carriage and the amount of sub-scanning separately from the data indicating the presence or absence of dots. Data necessary for such carriage control is
The data may be supplied to the color printer 20 by being attached to the top of the raster-row converted data. If the data for controlling the carriage is supplied at the same time as the data subjected to the raster-row conversion, the processing for the color printer 20 to control the carriage can be simplified.

FIG. 13 is an explanatory diagram showing an example of the data structure output by the computer 80 according to another aspect of the present embodiment. The number of data constituting the raster is written in the first two bytes of data, and the amount of sub-scanning performed after raster formation is written in the next one byte. Then 4
Subsequent to the byte, raster-row converted dot data is written.

FIG. 14 is a flowchart showing the flow of a process for forming dots by receiving the data as shown in FIG. 13 by the color printer 20. The color printer 20 receives the data from the computer 80 (step S3).
00), the first two bytes of data are decoded to recognize how many dots of data the raster is composed of (step S302), and the value is set in a counter (step S304). Subsequently, the data of the third byte is decoded to obtain the sub-scan amount to be sub-scanned after raster formation,
The value is stored (step S306). afterwards,
The dot data after the fourth byte is transferred to the drive buffer by the number of bits corresponding to the number of nozzles of the print head (step S308), and the value of the counter is decremented by one each time the transfer is performed (step S310). By repeating such processing until the value of the set counter becomes 0, a raster is formed on the print medium.

When the value of the counter becomes 0 (step S3)
12) Since one main scan has been completed, it is determined whether a raster of all image data has been formed (step S31).
4) If an unformed raster remains, step S
Sub-scanning of the carriage is performed according to the sub-scanning amount stored in 306 (step S316).

When outputting the last raster constituting the image, the computer 80 writes a predetermined value indicating that the raster is the final raster instead of the sub-scanning amount. Can be checked to determine whether all rasters have been formed. Of course, instead of this method, another well-known method, for example, a method of writing a predetermined value indicating the end of data at the end of data may be used. The dot formation process is completed when all the rasters forming the image have been formed by repeating the above process.

As described above, in another embodiment of the present embodiment, the color printer 20 acquires the number of dots forming the raster and the sub-scanning amount together with the data indicating the presence or absence of the dots, and according to this data, the carriage of the carriage is obtained. Main scanning and sub-scanning are performed.

The values such as the number of dots constituting the raster and the amount of sub-scanning vary depending on the image to be printed. For example, when printing a small image, the number of dots forming the raster is a small value, and the printing condition box of the image depends on the print quality required. Also fluctuates. In another aspect of the present embodiment, when the computer 80 outputs the raster-row converted data to the color printer 20, information such as the number of dots constituting the raster and the sub-scanning amount is attached to the head of the data. Since the output is performed, the color printer 20 can appropriately control the movement of the carriage by simple processing. Therefore, the color printer 20 has a high processing speed C
Quick printing can be performed without incorporating a PU.

Although the example shown in FIG. 13 includes only data on the number of dots forming the raster and the amount of sub-scanning in addition to the data indicating the presence or absence of dot formation,
Of course, other data (for example, whether or not to perform bidirectional printing) may be included.

Although various embodiments have been described above, the present invention is not limited to all the above embodiments, and can be implemented in various modes without departing from the gist of the invention. For example, a software program (application program) that realizes the above functions
May be supplied to a main memory or an external storage device of a computer system via a communication line and executed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a printing apparatus according to an embodiment.

FIG. 2 is an explanatory diagram showing a configuration of software.

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

FIG. 4 is an explanatory diagram showing a dot formation principle in the printer of the present embodiment.

FIG. 5 is an explanatory diagram showing a nozzle arrangement of the printer of the embodiment.

FIG. 6 is an explanatory diagram showing a principle of forming dots by simultaneously ejecting ink droplets by nozzles of the printer of the embodiment.

FIG. 7 is a flowchart illustrating a flow of a print processing routine according to the present exemplary embodiment.

FIG. 8 is an explanatory diagram conceptually showing the contents of the interlace processing performed by the image processing of the present embodiment.

FIG. 9 is a flowchart illustrating a manner in which the image processing apparatus according to the present embodiment repeatedly performs various types of processing in units of the number of raster lines formed in each main scan.

FIG. 10 is an explanatory diagram conceptually showing raster-row conversion of the present embodiment.

FIG. 11 is an explanatory diagram showing a data flow in the color printer of the embodiment.

FIG. 12 is an explanatory diagram illustrating an example in which a control circuit of the color printer according to the present embodiment is configured by a logic circuit.

FIG. 13 is an explanatory diagram illustrating an example of a data structure output from an image processing apparatus in another aspect of the present embodiment.

FIG. 14 is a flowchart illustrating a flow of processing for forming dots by analyzing data output from the image processing apparatus in another mode of the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 ... Color printer 21 ... Color scanner 23 ... CRT 24 ... Modem 26 ... Hard disk 30 ... Carriage motor 31 ... Drive belt 32 ... Pulley 33 ... Sliding shaft 34 ... Position detection sensor 35 ... Paper feed motor 36 ... Platen 40 ... Carriage 42 43, ink cartridges 44 to 47, print head 50, ink path 60, control circuit 61, one-chip microcomputer 62, RAM 63, drive buffer RAM 64, oscillator 65, distribution output device 66, I / F 67, counter 68, etc. Multiplexer 69 ... Counter 70 ... I / F 80 ... Computer 81 ... CPU 82 ... ROM 83 ... RAM 83 ... Ram 88 ... SIO 90 ... Video driver 91 ... Application program 92 ... Printer driver 93 ... Resolution conversion module 94 ... Color conversion Module 95: Halftone module 96: Interlace module 97: Raster-row conversion module

Claims (8)

[Claims] 1. A printing apparatus for receiving image data in a data format represented by the presence or absence of dots, and printing an image by forming dots on a print medium according to the image data, comprising: A print head configured by arranging a plurality of dot forming elements to be formed so that the interval between formed dots is one or more dots apart from each other; and printing that moves the print head relative to the print medium. Head moving means, image data receiving means for receiving the image data sent in the order in which the print head forms a plurality of dots by the plurality of dot forming elements, and synchronizing movement of the print head. A dot forming control unit for controlling dot formation in accordance with the received image data. 2. The printing apparatus according to claim 1, wherein the print head moving unit moves the print head in a main scanning direction, which is a direction intersecting a direction in which the plurality of dot forming elements are arranged. Means, and sub-scanning means for moving a relative position between the print head and the print medium in a sub-scanning direction, which is a direction intersecting with the main scanning direction, wherein the image data receiving means includes hand,
A printing apparatus comprising: means for receiving the number of dots formed in the main scanning direction and the moving amount of the print head in the sub scanning direction. 3. A method for receiving image data, converting the image into a data format represented by the presence or absence of dots, and converting the converted image data between a print head for forming dots on a print medium and the print medium. An image processing apparatus for outputting an image to a printing apparatus that prints an image while changing a relative position, wherein the print head includes dot formation information that is information on the number of dots that can be formed at a time and an interval between the dots. A print condition obtaining means for obtaining a print resolution as an index indicating the number of dots that can be formed per unit area, and converting the data of the image into a data format expressed by the presence or absence of dots based on the obtained print resolution. Data conversion means for changing the relative positions of the print head and the print medium, and forming the dots in a plurality of dots at a time. An image processing apparatus comprising: a dot formation order determination unit that determines based on the dot formation information; and a data output unit that outputs the converted image data to the printing device in accordance with the determined dot formation order. 4. The image processing apparatus according to claim 3, wherein the printing condition obtaining unit includes an information obtaining unit that can obtain predetermined information from the printing device. A printing apparatus which acquires the information by the information acquiring means. 5. The image processing apparatus according to claim 3, wherein the data output unit includes, in addition to the converted image data, the number of dots formed while the print head moves in a certain direction. An image processing apparatus, which outputs a movement amount by which the print head is moved in a direction intersecting the movement direction after forming the number of dots. 6. A printing method for receiving image data in a data format represented by the presence or absence of dots, and printing an image by forming dots on a print medium according to the image data, comprising: A print head that forms dots separated by one or more dots from each other is moved relatively to the print medium, and the image data that is sent in the order in which the print head forms a plurality of dots is generated. A printing method for receiving and controlling the dot formation of the print head in accordance with the received image data to print an image while synchronizing with the movement of the print head. 7. A method for receiving image data, converting the image into a data format in which dots are formed or not, and converting the converted image data between a print head that forms dots on a print medium and the print medium. An image processing method for outputting an image to a printing apparatus that prints an image while changing a relative position, wherein the print head forms dot formation information as information on the number of dots that can be formed at one time and an interval between the dots. Obtains a print resolution, which is an index representing the number of dots that can be formed per unit area, and converts the image data into a data format expressed by the presence or absence of dots based on the obtained print resolution. Judge the forming order of the dots formed by changing the relative position with respect to the printing medium based on the acquired dot forming information, An image processing method of outputting the conversion image data, the printing apparatus according to the order of forming the determined dot. 8. A print head that receives image data, converts the image into a data format represented by the presence or absence of dots, and converts the converted image data between a print head that forms dots on a print medium and the print medium. A computer-readable recording medium that records an image processing method for outputting an image to a printing apparatus that prints an image while changing a relative position, the method comprising: A function of acquiring dot formation information, which is information on dot intervals, and a print resolution, which is an index indicating the number of dots that can be formed by the printing apparatus per unit area, and, based on the acquired print resolution, A function of converting data into a data format represented by the presence or absence of dots; and a plurality of print heads while changing a relative position with respect to the print medium. A function of determining the formation order of dots to be formed based on the obtained dot formation information; and a function of outputting the converted image data to the printing device in accordance with the determined formation order of the dots. Recording medium on which is recorded.