JP2006103047A - Inkjet recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a processing speed of the whole apparatus by a memory access reduction, and also to decrease power consumption. <P>SOLUTION: Only lines with effective data (data which is not white) are read out from a RAM in the image transmission of a controller and an engine. The image transmission is carried out in units of one band by adding white lines in a block which carries out communication with the engine. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus.

  In recent years, OA equipment such as personal computers, copying machines, word processors, and the like has become widespread, and a recording apparatus that performs digital image recording by an ink jet method as a kind of image forming (recording) apparatus of these equipment has rapidly developed and spread. ing. In particular, along with the enhancement of the functions of OA devices, the colorization of these devices is progressing, and various color ink jet recording apparatuses have been developed accordingly.

  In general, an ink jet recording apparatus includes a carriage on which a recording head and an ink tank are mounted, a transport mechanism that transports recording paper, and a control circuit that controls these. In such a recording apparatus, ink is ejected while serially scanning a recording head having a plurality of ejection openings for ejecting ink droplets in the direction (main scanning direction) perpendicular to the recording paper conveyance direction (sub-scanning direction). On the other hand, the recording operation is executed by intermittently conveying the recording paper by an amount equal to the recording width of the recording head while ink is not ejected from the recording head. Further, in the case of a recording apparatus capable of color recording, a color image is formed by superimposing ink droplets ejected from a plurality of recording heads.

  In the ink jet recording apparatus, as a method of ejecting ink, a heating element (electrothermal energy converter) is provided in the vicinity of the ejection port, and an electric signal is applied to the heating element to locally heat the ink to change the pressure. Conventionally, a method for causing ink to discharge from an ejection port and a method for ejecting ink by applying a mechanical pressure to the ink using a piezoelectric element such as a piezoelectric element are known.

  This ink jet recording method records characters and figures by ejecting ink as fine droplets from a discharge port onto a recording medium according to a recording signal, and has low noise because it is non-impact. Because it has advantages such as low running costs, easy downsizing, and relatively easy colorization, it can be used in combination with computers and word processors, etc. Are widely used as image forming (recording) means in recording apparatuses such as copying machines, printers, and facsimiles.

  1 and 2 are block diagrams showing schematic configurations of a controller unit and an engine unit of the ink jet recording apparatus, respectively.

  First, the function and schematic operation of the controller unit will be described. The CPU 101 is connected to the host PCs 106 and 107 via the USB interface 104 or the IEEE 1394 interface 105. The ROM 109 stores a control program, the EEPROM 110 stores an updatable control program, a processing program, various constant data, and the like, and the host PC 106. The RAM 108 for storing the command signal and image information received from is accessed, and the recording operation is controlled based on the information stored in these memories. The instruction information input from the keys of the operation panel 112 is transmitted to the CPU 101 via the operation panel interface 111, and the LED lighting and LCD display of the operation panel 112 are similarly controlled via the operation panel interface 111 according to commands from the CPU 101. Is done. The expansion interface 115 is an interface for performing function expansion by connecting an expansion card such as a LAN controller or HDD. The image information is converted into dot data of each ink color by the image data processing block 113 and output to the engine (not shown). Similarly, various commands and status information are transmitted and received between the controller and the engine via the image data processing block 113.

  Next, the function and operation outline of the engine unit will be described. The engine unit is connected to a controller (not shown) via a band memory control block 212. The band memory control block 212 converts the data format into the print head data format, and the head data generation block 215 generates data to be sent to the head in consideration of multipath, connection lines, and the like. The CPU 201 accesses a ROM 203 storing a control program, an EEPROM 204 storing an updatable control program, a processing program, various constant data, and the like, and a RAM 202 for storing command signals and image information received from a controller (not shown). The recording operation is controlled based on the information stored in these memories. By operating the carriage motor 209 via the output port 205 and the carriage motor control circuit 207, the carriage 211 is moved, and by operating the paper feed motor 208 via the output port 205 and the paper transport motor control circuit 206. The paper transport mechanism 210 such as a transport roller is operated. Further, the CPU 201 controls the band memory control block 212, the head data generation block 215, and the print head control block 214 based on various information stored in the RAM 202 to drive the print head 215, thereby causing a desired image on the recording medium. Can be recorded.

  A power supply circuit (not shown) is supplied with a logic drive voltage Vcc (for example, 3.3 V) for operating the CPU and various control circuits, various motor drive voltages Vm (for example, 24 V), and a heat voltage for driving the recording head. Vh (for example, 12V) is output.

  As in the above-described processing process, the input multi-tone image information is converted into the number of gradations (dot data) that can be output by the inkjet recording apparatus by halftone processing. A dither method and an error diffusion method are widely known as this pseudo gradation expression method.

  In the dither method, a dither matrix including threshold values configured in a matrix is prepared, and one-to-one pixel comparison between each threshold value and each pixel of input data is performed to determine ON / OFF. On the other hand, in the error diffusion method, a diffusion coefficient is assigned to a peripheral pixel for a target pixel, and a quantization error generated in the target pixel is distributed to the peripheral pixels according to the diffusion coefficient. As a result, the density of the entire image is preserved, and a favorable pseudo gradation expression is possible.

  In general, the pattern dither method tends to have a lower image quality than an image to which the error diffusion method is applied. However, since parallel processing is possible, high-speed processing is easy. In the error diffusion method, it is difficult to perform high-speed processing because it is not possible to shift to processing of the next pixel until an error propagates.

  In the conventional ink jet recording method, it was necessary to use a special coated paper having an ink absorbing layer in order to obtain a color image with high color development without ink bleeding. A method of giving printability to plain paper that is used in large quantities on a machine has been put into practical use. Furthermore, it is desired to support various recording media such as OHP sheets, cloths, and plastic sheets. In order to meet these requirements, recording media (recording media) having different ink absorption characteristics were selected as necessary. At the same time, development and commercialization of a recording apparatus capable of performing the best recording irrespective of the type of the recording medium are being promoted. In addition, regarding the size of the recording medium, large-sized posters and woven fabrics such as clothes for advertisements have been required. Such an ink jet recording apparatus is in high demand in a wide range of fields as an excellent recording means, and it can be said that there is a demand for providing higher quality images, and the demand for higher speed is further increased.

  Generally, the color ink jet recording method uses three color inks of cyan (C), magenta (M), and yellow (Y), and further uses four color inks added with black (Bk). Realizes color recording. In such a color ink jet recording apparatus, unlike a monochrome dedicated ink jet recording apparatus that records only characters, various factors such as color development, gradation expression, and uniformity of an image are recorded in recording a color image. It is necessary to consider.

  However, the quality of the recorded image largely depends on the performance of the recording head unit. The slight differences in the characteristics of each nozzle that occur during the printhead manufacturing process, such as the shape of the printhead discharge ports and the variations in the quality of the electrothermal transducer (discharge heater), are due to the amount and direction of ink discharged. The direction of the image is influenced, and these effects appear as density unevenness in the finally formed recorded image, which causes deterioration in image quality. As a result, there are “white” portions that do not meet the area factor of 100% periodically in the main scanning direction of the recording head, or conversely, the dots overlap abnormally or white streaks occur. Will be. These phenomena are usually perceived as uneven density by the human eye.

  Therefore, a method called a multi-pass recording method has been proposed as a countermeasure against such density unevenness. Here, for the sake of simplicity, a case where a recording head that performs recording using a single color ink consisting of 8 nozzles is used will be described as an example.

  In the first scan of multi-pass printing, even-numbered row patterns are used, and in the second scan, odd-numbered row patterns are used. In the first scan, print data is thinned using a staggered pattern and a second scan is an inverted staggered pattern. A case where two-pass printing is realized by adopting a fixed mask method for generating pass data according to FIG. The staggered pattern is recorded in the first scan, the paper is fed by half the recording width (4 dot width), and then the inverted staggered pattern is recorded in the second scan to complete the recording. That is, the recording area in units of 4 dots is completed for each scan by alternately performing paper feeding in units of 4 dots and recording in a zigzag / reverse zigzag pattern.

  In this multi-pass printing, there is a method of thinning out print data using a random mask pattern in which print dots and non-print dots are randomly arranged (Patent Document 1).

  A case where two-pass recording is realized by employing a table reference method for generating pass data by this method will be described. 3 is a diagram showing an example of a mask table for each recording scan, table areas A and B are complementary mask tables used in the first pass and the second pass, respectively. The table is 1 bit / dot, 0 indicates a mask target, and 1 indicates a non-mask target. Mask tables A and B are tables each having a size corresponding to 12 pixels in the main scanning direction and 4 pixels in the sub-scanning direction, and are repeatedly developed in each direction and used as mask data. The number of nozzles provided in the recording head is 8, and the number of pixels corresponding to the paper conveyance amount in 2-pass recording is 8/2 = 4, which matches the sub-scanning direction sizes of Tables A and B.

  FIG. 4 is a diagram for explaining the state of recording scanning using the mask table shown in FIG. For 8 lines of data corresponding to 8 nozzles, A and B are applied as mask patterns every 4 lines. In each recording scan, image data masking (replaces recording dots with non-recording dots) is executed using the stored mask table to generate and output pass data. Specifically, by taking the logical product of the image data and the mask data, if the mask data is 1, the image data is output as it is. If the mask data is 0, the image data is This is realized by replacing with 0. All image areas are always masked in the order of A and B by two scans to generate print data. Here, the mask OFF (1) ratios of A and B are equally about 50%.

  Thus, by recording one line using two different nozzles, it is possible to form a high-quality image with suppressed density unevenness. In addition, the multi-pass printing method has the effect of suppressing bleeding (bleeding) by printing while drying the ink, and the print head temperature rise, which causes ejection failure, by reducing the printing dots for each scan. The suppression effect can be achieved at the same time. Although the main scanning direction has been described here, it is possible to further improve the image quality by thinning out and recording continuous dots in the sub-scanning direction. Further, when it is desired to realize image formation in the sub-scanning direction at a resolution higher than the nozzle resolution, the thinning recording in the sub-scanning direction is an essential process.

As described above, the pass data for each scan is generated by thinning out the print data using a random mask pattern in which print dots and non-print dots are randomly arranged as described above. In addition to the method of generating the pass data (referred to as the table reference method), the method of generating the pass data by thinning out the recording data using the even / odd column pattern or the zigzag / reverse zigzag pattern (referred to as the fixed mask method) In addition, a method of generating pass data by performing a thinning process while paying attention to recording dots (referred to as a data mask method) or a method using these in combination is known.
JP 7-52390 A

  Recent inkjet recording apparatuses are widely used from low-cost printers to printers capable of large-scale printing not only in the consumer field but also in offices because of the advantage that the number of parts is smaller than that of an electrophotographic apparatus and the size can be reduced.

  Against this background, an interface for exchanging image information and various control information with a host computer, etc., and an image for converting input image information into dot ON / OFF data for each ink color In an ink jet apparatus constituted by a controller (FIG. 1) constituted by a data processing block and the like, and an engine (FIG. 2) for conveying a recording sheet and driving a carriage and controlling a recording head to form an image (FIG. 2) A method of reducing the number of installed memories and accessing one memory from a plurality of control blocks has been promoted for reasons such as cost reduction. In this method, if access is simultaneously generated from a plurality of control blocks, a waiting time is generated, and the memory access is a bottleneck and the processing speed may not be increased. Therefore, it is conceivable to avoid this problem by reducing memory access.

  Also, in general, a printer with a long data length of one line, such as a large stretch printer, transfers only an area where valid data is divided into bands as shown in FIG. 6 and all bands are white. On the other hand, a method of filling the white on the engine side without performing image transfer and increasing the speed is used.

However, in such a method, as shown in FIG. 7, even if there is one line or data in one band, image transfer is performed in band units. Therefore, depending on the image, a lot of useless white data is read from the memory, which hinders the improvement of the processing speed.
The present invention has been made in view of the above problems, and an object thereof is to provide an ink jet apparatus capable of improving the processing speed of the entire apparatus by reducing memory access. Another object of the present invention is to provide an ink jet recording apparatus capable of reducing power consumption.

  In order to solve the above problems, an ink jet recording apparatus of the present invention scans a print head having a plurality of ejection portions a plurality of times on the same area of a recording medium, and inks the recording medium based on input image information. Is an ink jet recording apparatus that prints an image by forming dots on each pixel, and storage means for storing image data, memory controller means for controlling the storage means, and all white data The white line detection means for detecting a line and the memory controller means read out from the storage means only the lines that are not detected as white lines by the white line detection means.

  Another ink jet recording apparatus of the present invention scans a print head having a plurality of ejection portions a plurality of times on the same area of a recording medium, and ejects ink onto the recording medium based on input image information. An ink jet recording apparatus that prints an image by forming dots on each pixel, and stores a storage unit that stores image data, a memory controller unit that controls the storage unit, and a line that is all white data White line detection means, printing means for controlling the operation of the print head, transfer means for transferring image data to the printing means in band units, and the memory controller means include white line detection means for the white line detection means. And only lines that are not detected are read from the storage means, and white lines are added by the transfer means. That.

  Another ink jet recording apparatus of the present invention scans a print head having a plurality of ejection portions a plurality of times on the same area of a recording medium, and ejects ink onto the recording medium based on input image information. An ink jet recording apparatus that prints an image by forming dots on each pixel, and stores a storage unit that stores image data, a memory controller unit that controls the storage unit, and a line that is all white data The white line detection means, the printing means for controlling the operation of the print head, the transfer means for transferring image data to the printing means, and the memory controller means are detected as white lines by the white line detection means. Only N lines that did not exist are read from the storage means, and white lines are added by the transfer means to transfer M lines (M> = N). And performing said printing means.

  As described above, a print head having a plurality of ejection units is scanned a plurality of times on the same area on the recording medium, and ink is ejected onto the recording medium based on the input image information to form dots on each pixel. In the inkjet recording apparatus that prints an image by forming, the processing speed of the entire apparatus can be improved by reducing memory access in the transfer between the controller engines. It also has excellent effects such as reducing power consumption by reducing memory access.

  The best mode for carrying out the present invention will be described below based on examples.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 5 shows a configuration of a recording unit of the ink jet recording apparatus according to the present invention.

  Reference numeral 501 denotes a recording head, which is an ink tank in which four color inks of black (Bk), cyan (Cy), magenta (Mg), and yellow (Ye) are sealed, and four independent heads corresponding to each. It is comprised by the multihead which consists of. The number of nozzles for each color is 16 nozzles. A carriage 502 supports the recording head 501 and moves them together with recording. The carriage 502 can be moved using the stay 506 in the X direction. The carriage 502 is at the home position HP shown in the drawing during standby such as a non-recording state. A paper feed roller 503 rotates while suppressing the recording paper 504 and feeds the recording paper 504 in the Y direction as needed. Reference numeral 505 denotes a paper feed roller that feeds the recording paper 504 and plays a role of suppressing the recording paper 504 in the same manner as the paper feed roller 503 and the auxiliary roller. Here, the recording head 501 has 1024 nozzles respectively arranged in the paper feed direction for the four colors Bk, Cy, Mg, and Ye.

  A basic recording operation in the above configuration will be described.

  During the standby, the carriage 502 at the home position HP is moved in the X direction in response to a recording start command, and performs recording by ejecting ink onto the recording paper 504 according to the recording data by a plurality of nozzles of the recording head 501. When the recording of the recording data to the end of the recording paper 504 is completed, the carriage 502 returns to the original home position. As the paper feed roller 503 rotates in the direction of the arrow, the paper is fed by a predetermined width in the Y direction, and the carriage 502 again ejects ink while moving in the X direction and starts recording. Data recording is realized by repeating such scanning operation and paper feeding operation.

  The ink jet recording apparatus of this embodiment converts an interface for exchanging image information and various control information with a host computer or the like, and converts input image information into dot ON / OFF data for each ink color. And a controller (FIG. 1) configured with an image data processing block, and an engine (FIG. 2) that transports recording paper and drives a carriage and controls the recording head to form an image. ing.

  Further, the ink jet recording apparatus according to the present embodiment employs a multi-pass recording method in which the same recording area is scanned a plurality of times to form an image. As described above, multi-pass printing forms an image using a plurality of nozzles for one line, thereby suppressing density unevenness due to slight differences in the ink discharge amount and discharge direction for each nozzle, and simultaneously passing This is a recording method in which the recording duty is reduced to prevent image quality deterioration due to ink bleeding or the like.

  Here, description will be given by taking two-pass printing as an example. The carriage is driven at a speed equal to or lower than the maximum ejection frequency, and each scan completes an image by two print scans while referring to a mask table. The amount of paper transport performed between scans corresponds to the width of nozzles obtained by dividing the number of used nozzles by two.

  As described above, the recording head has 1024 nozzles for each color, and the nozzle numbers are assigned as # 0, 1, 2, 3,. In the present embodiment, a fixed mask method is employed in which even columns and odd columns are alternately formed. In the first pass, only even-numbered rows of X coordinates = 2n are formed. Then, after carrying the paper having a width corresponding to half of the number of used nozzles, in the second pass, only odd-numbered dots with X coordinates = 2n + 1 are formed. Then, paper is transported with a width corresponding to half of the number of used nozzles. Thereafter, even-numbered dot formation, paper conveyance, odd-numbered dot formation, and paper conveyance are sequentially repeated.

  Hereinafter, a control method for reducing memory access in image transfer between the controller and the engine will be described in detail with reference to the drawings. FIG. 10 is a schematic block diagram of the image data processing block in the controller and the band memory memory control block in the engine, focusing on the block for controlling the image transfer between the controller and the engine and its periphery.

  The controller 1 includes a CPU 101, an SDRAM 114, a memory controller 1001 that controls reading and writing to the SDRAM 114, an engine IF control unit 1002 that performs communication with the engine 2, and a white line detection that detects whether all the lines are white data. A portion 1006 is provided.

  The engine 2 includes a CPU 201, a memory 213, a memory controller 1007 that controls reading and writing to the memory 213, a controller IF control unit 1003 that communicates with the controller 1, a print width data generation unit 1004 that aligns with print width data, a print A raster / column conversion unit 1005 for performing raster / column conversion for matching with the head is provided.

  After performing desired image processing, the image data is temporarily stored in the RAM 108 via the memory controller 103. At the time of image transfer from the controller to the engine, the white line detection unit 1006 first determines whether there is a white line, and reads only image data of lines that are not white lines from the SDRAM 114 via the memory controller 1001. The engine IF control unit 1002 internally generates white data when transferring a line determined as a white line by the white line detection unit 1006. The engine IF control unit 1002 transfers the data to the engine in units of one band. The controller 1 and the engine 2 are connected mainly by a parallel bus for transferring images and a serial bus for transmitting and receiving various commands and status information between the controller and the engine. When the data received from the controller 1 via the controller IF control unit 1003 is less than the print width, the print width data control unit 1004 performs white data fill or the like to match the data to the print width, and then the memory controller 1007 And stored in the memory 213. Then, the raster / column conversion unit 1005 converts the data stored in the memory 213 in the raster direction as shown in FIG. 9 in the column direction in accordance with the print head 217 and outputs it, and transfers it to the head data generation unit block. .

  Next, a control method for reducing memory access in image transfer between the controller and the engine, which is characteristic in the present invention, will be described in detail with reference to FIG.

  After detecting the end of the image processing, the CPU 101 of the controller instructs the image data processing block 113 to transfer the image to the engine (S1101). Next, the line counter is initialized (N = 0) (S1102). Although not shown in the figure, the CPU 101 detects in advance whether one line is all white within one band unit. If all the lines are white as shown in FIG. If there is, “1” is written to the register of the image data processing block 113. In S1104, it is determined whether the Nth line is all white. If the Nth line is all white, the engine IF control unit 1002 generates white data for all the lines without reading the data from the RAM. (S1105). If the Nth line is not all white, the image data of the Nth line is read from the RAM (S1106), and transferred to the engine in S1107. Until the image transfer for one band including all white lines is completed, the line counter is incremented in S1103, and S1104 to S1107 are repeated (S1108).

  In this embodiment, processing is performed by determining whether each line is a white line. However, it is clear that determining whether each line is a white line can also be realized with the same configuration. .

  If such control is performed, unnecessary memory access is not performed in image transfer between the controller and the engine. Therefore, even in a printer having a high-speed, high-quality head, memory access can be minimized.

(Second embodiment)
In the second embodiment, a white line is detected when bit image data is generated by the printer driver of the host computer, and the information is transferred to the controller together with the bit image data. The second embodiment will be described in detail with reference to FIG.

  FIG. 12 is a schematic block diagram of the ink jet apparatus in the second embodiment. A host computer 1201 including a personal computer, a workstation, and the like includes a printer driver 1202 that processes data passed from the upper software into data that allows the printer to operate, and an interface control unit that communicates with the printer 1220. 1205. The printer driver 1202 is provided with a bit image data generation unit 1203 that converts (rasterizes) into bit image data, and a white line detection unit 1204 that detects whether a white line is converted into bit image data.

  When document data created by an application program such as document creation software is input, the printer driver 1202 converts the document data into predetermined bit image data in the bit image data generation unit 1203. In addition, the white line detection unit detects whether or not each line is white when the bit image data generation unit 1203 converts it into bit image data. When all the lines are white as shown in FIG. Is transferred to the printer 1220 via the interface control unit 1205 as information “0” and “1” when there is data, together with the pit image data.

  The printer 1220 includes a controller (FIG. 1) and an engine (FIG. 2).

  The controller 1 includes an interface control unit 1221 for communicating with the host computer 1201, a RAM 108, a memory controller 103 for controlling reading and writing to the RAM 108, and an image processing unit 1222 for performing various image processing such as color conversion and binarization. An engine IF control unit 1223 is provided for transferring print data by performing masking, thinning, etc. in a format suitable for the engine, and for communicating with the engine.

  The controller 1 and the engine 2 are connected mainly by a parallel bus for transferring images and a serial bus for transmitting and receiving various commands and status information between the controller 1 and the engine 2.

  The engine includes a paper feed mechanism that transports paper, a print head that discharges ink droplets onto the paper at a predetermined timing, and a carriage mechanism that travels a carriage on which the print head is mounted.

  Bit image data and the like transmitted from the host computer 1201 are received by the interface control unit 1221 and temporarily stored in the RAM 108 via the memory controller 103.

  The image processing unit 1222 determines whether there is a white line based on the white line detection information transferred together with the bit image data, and reads only image data of a line that is not a white line from the RAM 108 via the memory controller 103. Then, after performing desired image processing, the engine IF control unit 1223 transfers the data to the engine in units of one band, and generates white data internally when transferring a line determined to be a white line by the white line detection unit 1204. Forward to 2.

  Next, the characteristic control method in the second embodiment will be described in detail with reference to FIG.

  The host computer 1201 converts document data into predetermined bit image data in the printer driver 1202, detects whether it is a white line, and transfers the data to the printer 1220 via the interface control unit 1205 (S1301). . The transferred bit image data is temporarily stored in the RAM (S1302). Next, the line counter is initialized (N = 0) (S1303). In step S1305, it is determined whether the Nth line is all white. If the Nth line is all white, the engine IF control unit 1223 generates white data for all the lines without reading the data from the RAM. 2 (S1306). If the Nth line is not all white, the image data of the Nth line is read from the RAM (S1307), and desired image processing such as color conversion and binarization is performed in S1308, and then to the engine 2 in S1309. Forward. The line counter is incremented in step S1304 until the image transfer for one band including all white lines is completed, and steps S1304 to S1309 are repeated (S1310).

  In the present embodiment, the method of transferring the image processing unit 1222 directly to the engine 2 via the engine IF control unit 1223 after the image processing unit 1222 has been described. The present invention is also effective in a method of transferring to an engine after image processing is completed.

  According to the present embodiment, unnecessary memory access is not performed in the two modules of the image processing unit 1222 and the engine IF control unit 1223, so that more effective memory access can be realized.

  Further, in this embodiment, an example in which the memory is not accessed in the case of data of all lines in two modules of the image processing unit 1222 and the engine IF control unit 1223 has been described. The present invention is effective even when accessing.

  Incidentally, the present invention is not limited by the operation principle or configuration of the recording head. That is, the recording head is provided with a heating element (electrical / thermal energy conversion element) in the vicinity of the discharge port, and by applying an electric signal to the heating element, the ink is locally heated to cause a pressure change, and the ink is discharged. A thermal system that ejects ink from an ejection port may be used, or a piezoelectric system that ejects ink by applying mechanical pressure to the ink using an electrical / pressure converting means such as a piezoelectric element.

  The form of the ink jet recording apparatus according to the present invention is not limited to an image output apparatus of an information processing apparatus such as a computer or a word processor, but is provided integrally or separately, and a copying apparatus or a communication function combined with a reading apparatus. It may be a facsimile machine having

It is a schematic block diagram of the controller part in an inkjet recording device. It is a schematic block diagram of the engine part in an inkjet recording device. It is a figure which shows an example of the mask table for multipass 2 pass data production | generation. It is a figure explaining the mode of multipass printing using the mask table of FIG. 1 shows a configuration of a recording unit of an ink jet recording apparatus. It is a figure explaining the band skip of a prior art example. It is a figure explaining the problem of the band skip of a prior art example. It is a figure explaining the discrimination method of all the white lines in this invention. It is a figure explaining raster column conversion. It is a schematic block diagram which shows the structure of the recording control method in the Example of this invention. 6 is a flowchart illustrating a recording control operation in the first embodiment of the present invention. It is a schematic block diagram which shows the structure of the recording control method in 2nd Example of this invention. 6 is a flowchart illustrating a recording control operation in the second embodiment of the present invention.

Explanation of symbols

101 CPU
102 Bus Bridge 103 Memory Controller 104 USB Interface 105 IEEE1394 Interface 106, 107 Host PC
108 RAM
109 ROM
110 EEPROM
111 Operation Panel Interface 112 Operation Panel 113 Image Data Processing Block 114 SDRAM
115 Extended interface 201 CPU
212 Band memory control block 213 Memory 214 Print head control block 215 Head data generation block 217 Print head 1001 Memory controller 1002 Engine IF control unit 1003 Controller IF control unit 1004 Print width data generation unit 1005 Raster / column conversion unit 1006 White line detection unit 1007 Memory controller

Claims (5)

An inkjet recording apparatus that scans a print head having a plurality of ejection units a plurality of times on the same area of a recording medium, ejects ink onto the recording medium based on input image information, and forms dots on each pixel. And
Storage means for storing image data;
Memory controller means for controlling the storage means;
White line detection means for detecting lines that are all white data;
The ink-jet recording apparatus according to claim 1, wherein the memory controller means reads only lines that have not been detected as white lines by the white line detection means from the storage means. An inkjet recording apparatus that scans a print head having a plurality of ejection units a plurality of times on the same area of a recording medium, ejects ink onto the recording medium based on input image information, and forms dots on each pixel. And
Storage means for storing image data;
Memory controller means for controlling the storage means;
White line detection means for detecting lines that are all white data;
Printing means for controlling the operation of the print head;
Transfer means for transferring image data in band units to the printing means;
The ink jet recording apparatus, wherein the memory controller means reads only lines that are not detected as white lines by the white line detection means from the storage means and adds white lines by the transfer means. An inkjet recording apparatus that scans a print head having a plurality of ejection units a plurality of times on the same area of a recording medium, ejects ink onto the recording medium based on input image information, and forms dots on each pixel. And
Storage means for storing image data;
Memory controller means for controlling the storage means;
White line detection means for detecting lines that are all white data;
Printing means for controlling the operation of the print head;
Transfer means for transferring image data to the printing means;
The memory controller means reads only N lines that are not detected as white lines by the white line detection means from the storage means, adds white lines by the transfer means, and transfers M lines (M> = N). An ink jet recording apparatus, which is performed on a printing unit.   4. The inkjet recording apparatus according to claim 1, wherein the storage unit is accessed from a plurality of control units.   5. The ink jet recording apparatus according to claim 1, wherein the memory controller means can perform control when the storage means is accessed from a plurality of control means.