JP3774527B2 - Image recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image recording apparatus having a plurality of replaceable print head units, and more particularly to an image recording apparatus configured to be able to correct a deviation in the nozzle arrangement direction between a plurality of units.
[0002]
[Prior art]
A recording apparatus such as a printer or a facsimile is configured to drive a recording element of a head based on print data and to form an image composed of a dot pattern while conveying (sub-scanning) a recording material. . As a recording method, a line recording method in which recording is performed only by conveyance (sub-scanning) by a recording head in which recording elements for one line are arranged, and recording is performed by a recording head that is conveyed line by line and mounted on a carriage. There is a serial recording method in which recording is performed while scanning in the width direction (main scanning direction) of the material.
[0003]
For color printing, a plurality of recording heads are mounted according to ink colors such as black, cyan, magenta, and yellow. Such a recording apparatus is generally configured so that a recording head unit including a recording head, a head drive circuit, and the like are unitized and exchangeable for each unit. However, in a serial printer, dot misalignment occurs when each color is overlaid due to mechanical variations between color heads or mechanical displacements after replacing the head unit. It was necessary to adjust so as to make it small, and accurate adjustment was difficult.
[0004]
Japanese Patent Laid-Open No. 61-222746 describes a technique for solving such a problem in a line printer apparatus. In the technique described in Japanese Patent Application Laid-Open No. 61-222746, print data sent from a host computer is put in a shift register having an arbitrary length, and an arbitrary shift output line of this shift register is selected and latched. The horizontal registration between the color head units is adjusted.
[0005]
[Problems to be solved by the invention]
The above conventional example relates to the adjustment of the lateral registration between the head units in the line printer device. However, the serial printer device having a plurality of head units also has the same problem, and FIG. It is necessary to correct the print data in order to adjust the vertical deviation (nozzle arrangement direction) between the plurality of head units A and B as shown in B). Furthermore, in recent years, the printing resolution tends to be high, and the dot diameter of one dot is small, and a slight mechanical shift appears as a large number of dot shifts on the image, causing a reduction in image quality. ing.
[0006]
Therefore, in the conventional serial printer, as shown in FIG. 10, in order to print, for example, 128 nozzles, (128 + n) nozzle head units A and B are used, and the amount of deviation in the nozzle arrangement direction between both head units A and B is increased. On the other hand, correction was made within the equivalent of n nozzles, and printing with 128 nozzles was made possible. However, as the dot diameter of one nozzle decreases, the value of n for correction must be increased, which is not suitable for a long head having a large number of nozzles.
[0007]
The present invention has been made in view of the above problems, and an image recording apparatus capable of obtaining a high-quality image without dot displacement by correcting displacement in the nozzle arrangement direction between a plurality of head units. The purpose is to provide.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the image recording apparatus of the present invention provides the first recording head and the second recording head each having a nozzle row composed of M nozzles arranged in a predetermined direction . The second recording head is shifted by N nozzles in the predetermined direction with respect to the recording head, and the first recording head and the second recording head scan the recording material for recording. A memory unit that holds data corresponding to the nozzle row in units of L bits, and a first holding unit that holds data of 2 × L bits from consecutive addresses along the predetermined direction with respect to the memory unit. And 2 × L bits of data held by the first holding means, and a boundary between L bit unit data held by the memory means and a boundary of data used in printing of each scan After shifting on the basis of the difference between, and the first shift output means for outputting the L-bit data, the L bits of data to which the first shift output means outputs inputted sequentially to the M nozzle Second holding means for holding corresponding M-bit data, and second shift output for shifting and outputting the M-bit data held by the second holding means in accordance with a deviation of N nozzles in the predetermined direction And transfer means for transferring the M-bit data output from the second shift output means to the second recording head .
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0020]
(First embodiment)
FIG. 1 is a block diagram of a control system of a serial printer suitable for carrying out the present invention.
[0021]
Reference numeral 111 denotes an MPU that controls the printer driver 112 and the like. A ROM 104 stores a program executed by the MPU 111. Reference numeral 101 denotes an interface (I / F) that receives data from a host computer or the like. The received data is stored in a reception buffer (not shown) in the storage area of the memory 102 such as a DRAM. The data stored in the reception buffer is held in an image buffer (not shown) in a storage area of a memory 102 such as a DRAM (hereinafter also referred to as DRAM 102) after command analysis.
[0022]
Reference numeral 103 denotes an ASIC that performs interface control, image conversion, print data processing, print data transfer, print timing control, and the like in the present embodiment. 106 in the ASIC 103 performs resolution conversion, sequential data in the main scanning direction (carriage scanning direction), and sequential data in the sub-scanning direction (conveyance direction) substantially perpendicular to the main scanning direction, with respect to the data held in the image buffer. This is an image conversion circuit that performs HV conversion or the like for conversion into the image data. The print data processing circuit 107 in the ASIC 103 performs a mask process for the data after HV conversion and a print data process for correcting a shift in the vertical direction (arrangement direction of nozzles as recording elements) between the plurality of head units.
[0023]
Reference numeral 108 in the ASIC 103 is a printing timing control circuit that generates a driving signal for driving the recording head 110 and sets a driving timing delay between the heads. 109 in the ASIC 103 is a print data transfer circuit that transfers data to be actually printed (recorded) to which the print data processing has been performed, to the recording head 110. In this way, the recording head 110 performs printing at a predetermined timing by the print data transferred from the print data transfer circuit 109 and the drive signal supplied from the print timing control circuit 108.
[0024]
In the present embodiment, a serial printer having a recording head composed of a plurality of head units in which 128 nozzles are arranged substantially in the sub-scanning direction will be described.
[0025]
FIG. 2 is a detailed block diagram of the print data processing circuit in the present embodiment.
[0026]
Reference numerals 201a, 201b, and 201c denote registers that set values corresponding to the upper-end mask value, lower-end mask value, and data shift amount of the recording head. Here, the upper end is the end on the upstream side in the transport direction, and the lower end is the end on the downstream side in the transport direction. Reference numeral 202a denotes a latch, which is data DATA [15. . 0] is latched. A latch 202b latches data from the latch 202a. The latches 202a and 202b constitute a 16-bit wide shift register. A bit shift circuit 203 shifts data by the value set in the register 201c from the current latest data output from the latch 202a and the previously read data output from the latch 202b. The bit shift circuit 203 can shift from 0 to 15 bits according to the set value, and the used nozzle can be arbitrarily changed.
[0027]
Reference numeral 204 denotes a 16-bit × 8 data latch. The data after the bit shift by the bit shift circuit 203 is converted into eight latch signals DTLT [7. . 0] to latch in 16-bit units. Therefore, the output data of the data latch 204 is 128 bits corresponding to the recording width of the recording head. A mask pattern generation circuit 205 generates a mask pattern for 128 nozzles in accordance with the values set in the registers 201a and 201b.
[0028]
A mask circuit 206 masks the data latched by the data latch 204 with the mask pattern generated by the mask pattern generation circuit 205. A shift clock generation circuit 207 generates a shift clock to be supplied to the shift register 208 for correction of the shift according to the shift amount of the head unit. Reference numeral 208 denotes a shift register, which corrects a deviation in the nozzle arrangement direction between the head units for the data masked by the mask circuit 206.
[0029]
In the present embodiment, with the above-described configuration, a dot shift in the vertical direction (nozzle arrangement direction) between a plurality of head units juxtaposed in a direction substantially perpendicular to each nozzle arrangement direction is corrected and a recording pass is performed. Printing is performed by arbitrarily changing the nozzle used according to the number.
[0030]
The present embodiment will be described below along the data flow. First, input data sent from a host computer is received via the interface 101, and the received data is stored in a reception buffer in a storage area of a memory 102 such as a DRAM. The data stored in the reception buffer is held in the image buffer in the storage area of the memory 102 such as DRAM after command analysis.
[0031]
Since the data stored in the image buffer is sequential data in the main scanning direction, image conversion is performed when raster data (sequential line data in the main scanning direction) corresponding to the recording width of the recording head is stored in the image buffer. The circuit 106 converts the data into sequential data in the sub scanning direction (HV conversion), and writes the converted data back to the image buffer. In this way, after the print data corresponding to one scan of the printhead is stored, the print data corresponding to each print element of the printhead is read from the image buffer, and print data processing is performed.
[0032]
Incidentally, in a serial printer having a plurality of (here, two) head units juxtaposed in a direction substantially perpendicular to each nozzle arrangement direction, as shown in FIG. Occurs. In FIGS. 9A and 9B, they are shifted in the opposite direction by 2 dots. In the case of FIG. 9 (A) or (B), in order for the dots printed by unit A and the dots printed by unit B to overlap, the data of the other unit is corrected based on either unit. There must be.
[0033]
For example, in the case of FIG. 9A, the data of unit A must be corrected by 2 dots with unit B as a reference. That is, the data of unit A is shifted by 2 dots in the nozzle lower end direction with the upper end of unit B as a reference. In the case of FIG. 9B, correction is performed by shifting the data of unit B by two dots in the same direction with the upper end of unit A as a reference. Hereinafter, the case of FIG. 9A will be described.
[0034]
Due to the deviation of 2 dots in the nozzle arrangement direction between the head units, a maximum of 126 nozzles out of 128 nozzles are used during 2-pass printing, and a maximum of 124 nozzles are used during 4-pass printing. Do. At this time, for example, at the time of 2-pass printing, as shown in FIG. 3 (A), multi-pass printing is performed by conveying 63 nozzles for each line printing, and at the time of 4-pass printing, FIG. As shown, multi-pass printing is performed by conveying 31 nozzles for each line printing.
[0035]
FIG. 4 is an explanatory diagram showing the correspondence between data on the DRAM and each nozzle of the recording head when 2-pass printing is performed using 126 nozzles. A solid line on the recording head represents a delimiter in units of 16 nozzles, and a broken line represents a delimiter of data on the DRAM (in units of 16 bits).
[0036]
As shown in FIG. 4, when 2-pass printing is performed using 126 (= 2 × 63) nozzles, the carry amount is equivalent to 63 nozzles as described above. However, since the bus width of the DRAM is 16 bits, there is a case where the boundary of each scan is different from the boundary of the data on the DRAM because there is no relation between the two numbers when carrying 63 passes by carrying 63 nozzles. For example, 1 dot is different in the second scan, 2 dots are different in the third scan, and 3 dots are different in the fourth scan. Therefore, as described later with reference to FIG. 7, 16-bit data is read twice from the DRAM, and the data is shifted by the bit shift circuit 203 based on the value set in the bit shift setting register 201c. Data corresponding to each of the 16 nozzles divided into 8 from the upper end of the head is sequentially generated, and printing is performed using this data.
[0037]
In FIG. 2, 16-bit data read from the DRAM is sequentially latched in the latch 202a by the latch clock LTCLK signal, but the latches 202a and 202b constitute a 16-bit width shift register, so that The data latched in the latch 202a by the latch clock signal LTCLK is latched in the latch 202b. That is, if the data latched in the latch 202a is the nth read data, the data latched in the latch 202b is the (n-1) th read data. Data shifted from these data by the bit shift circuit 203 is sequentially latched in the data latch 204 in units of 16 bits.
[0038]
FIG. 5 shows the timing until data is read from the DRAM and latched in the data latch 204 as described above.
[0039]
Data DATA [15 .. read from DRAM in synchronization with the system clock SYSCLK (FIG. 5A). . 0] (FIG. 5B) is latched in the latch 202a by the latch clock LTCLK signal (FIG. 5C), and at the same time, the data latched in the latch 202a is latched in the latch 202b. Bit-shifted data SFTDAT [15. . 0] (FIG. 5D) is generated and latched at the upper 16 bits of the data latch 204 by the latch signal DTLT7. The latch clock LTCLK signal and the latch signal DTLT are synchronized with the system clock SYSCLK.
[0040]
Thereafter, the data SFTDAT [15. . 0] (FIG. 5D) is generated and is sequentially latched in the data latch 204 in units of 16 bits by the latch signals DTLT6,..., DTLT1, DTLT0 (FIGS. 5E to 5H). In order to generate data for 128 nozzles, 16-bit data is read out from the DRAM nine times.
[0041]
Here, 128-bit data corresponding to the recording width of the recording head is generated. Since the data to be used is 126-bit data from the upper end, it is necessary to mask the 2-bit data at the lower end.
[0042]
Therefore, a mask pattern is generated by the mask pattern generation circuit 205 based on the values set in the upper end mask setting register 201a and the lower end mask setting register 201b, and the lower 2 bits of data are masked by the mask circuit 206. Since the 126-bit data to be actually printed is generated by the processing so far, the deviation in the nozzle arrangement direction between the actual head units is corrected next.
[0043]
In the positional relationship between the head units in FIG. 9A, since the unit B is used as a reference, the MSB of the generated data may correspond to the position of the third nozzle from the upper end of the recording head of the unit A. Therefore, the shift in the nozzle arrangement direction between the head units is corrected by shifting the data by 2 dots in the shift register 208 using the shift clock generated by the shift clock generation circuit 207. Since unit B is a reference, no shift clock is generated for this data, so the data is not shifted.
[0044]
For the two-dot displacement as shown in FIG. 9A, the physical displacement in the nozzle arrangement direction between the head units is corrected by the print data processing as described above, and a high-definition image without dot displacement is obtained. Obtainable. When the shift amounts are different, the shift amount by the shift clock of the shift clock generation circuit 207 is varied. In this embodiment, the nozzle is used from the uppermost nozzle of the recording head. However, the shift amount of the bit shift circuit 203 and the latch of the data latch 204 that latches data in units of 16 bits are set. It is possible to print data corresponding to nozzles at arbitrary positions of the recording head. For example, as shown in FIG. 6, it is possible to obtain a high-quality image with no dot deviation by performing printing while arbitrarily changing the number of used nozzles to, for example, 126 nozzles according to the number of recording passes.
[0045]
(Second Embodiment)
In the above embodiment, a method has been described in which the amount of displacement is corrected with respect to the displacement in the nozzle arrangement direction between the plurality of head units, and the number of used nozzles is changed according to the amount of displacement and the number of recording passes. . Further, in the present embodiment, paper or the like is obtained after correcting a deviation in the nozzle arrangement direction between a plurality of recording head units by adding a small-scale circuit to the serial printer having the above-described configuration. The control for printing the lower end of the recording material will be described.
[0046]
FIG. 7 is a detailed block diagram of the print data processing circuit in the present embodiment.
[0047]
Reference numerals 701a, 701b, and 701c are registers that set values corresponding to the mask value at the upper end of the print head, the mask value at the lower end, and the data shift amount. Reference numeral 702a denotes a latch, which is data DATA [15. . 0] is latched. A latch 702b latches data from the latch 702a. The latches 702a and 702b constitute a 16-bit wide shift register. A bit shift circuit 703 shifts data by the value set in the register 701c from the current latest data output from the latch 702a and the previously read data output from the latch 702b. In the bit shift circuit 703, 0-15 bits can be shifted by this set value, and the used nozzle can be arbitrarily changed.
[0048]
Reference numeral 704 denotes a 16-bit × 8 data latch. The data after the bit shift by the bit shift circuit 703 is converted into eight latch signals DTLT [7. . 0] to latch in 16-bit units. Therefore, the output data of the data latch 704 is 128 bits corresponding to the recording width of the recording head. A mask pattern generation circuit 705 generates a mask pattern for 128 nozzles according to the values set in the registers 701a and 701b.
[0049]
A mask circuit 706 masks the data latched by the data latch 704 with the mask pattern generated by the mask pattern generation circuit 705. A shift clock generation circuit 707 generates a shift clock to be supplied to the shift registers 708 and 709 in accordance with the shift amount for correcting the shift. Reference numeral 708 denotes a shift register, which corrects a deviation in the nozzle arrangement direction between the head units for the data masked by the mask circuit 706. Reference numeral 709 denotes a shift register, which shifts data in the reverse direction of the shift register 707. A selector 710 selectively switches and outputs the output data of the shift register 708 and the output data of the shift register 709.
[0050]
Considering the case where there is a deviation shown in FIG. 9A as in the above embodiment, when performing lower end printing, the data of unit B is shifted by 2 dots in the nozzle upper end direction with reference to the lower end of unit A. Therefore, the amount of deviation must be corrected.
[0051]
Here, FIG. 8 is a diagram showing print data processing at the time of lower end printing. For example, it is assumed that the hatched dots in the data stored at addresses $ 00a0h to $ 00aah on the DRAM of the print image represent valid print data. Of the 16-bit data stored at address $ 00aah corresponding to the lowermost end of the print image, the lower LSB to the second bit are invalid. Therefore, in order to perform the lower-end printing, the third bit data from this LSB is used. Must be corrected to correspond to the lowest nozzle of the recording head.
[0052]
Therefore, in FIG. 8, a value is set so that the data read into the bit shift setting register 701c is shifted by 14 bits. As described above, the data SFTDAT [15. . 0] and latched in the data latch 704 by the latch signal DTLT4. Thereafter, every time data is read from the DRAM, the data SFTDAT [15. . 0] and is sequentially latched in the data latch 704 in units of 16 bits by the latch signal DTLT3,... DTLT0.
[0053]
Here, the effective print data (dotted lines in FIG. 8) is stored at positions corresponding to the nozzles of the recording head, but the other nozzle data (open dots 80 in FIG. 8) I don't know the value, so I need to mask it. Therefore, the number of masks is set so as to mask invalid data in the upper end mask setting register 701a and the lower end mask setting register 701b, and the mask pattern generation circuit 705 generates a mask pattern based on the values. A mask circuit 706 masks data other than nozzles in which valid print data is stored.
[0054]
Since the nozzle data to be actually printed has been generated by the processing so far, the deviation in the nozzle arrangement direction between the actual head units is corrected next. In the positional relationship between the head units in FIG. 9A, since the unit A is used as a reference, the LSB of the generated data should correspond to the position of the third nozzle from the lower end of the recording head of the unit B. Therefore, the shift in the nozzle arrangement direction between the head units is corrected by appropriately shifting the data in a predetermined direction corresponding to the print location of the recording material by the shift clock generated by the shift clock generation circuit 707.
[0055]
The shift register 708 shifts the data from the MSB to the LSB direction (from the upper end to the lower end of the recording head) of the data in the same manner as the shift register 208 in FIG. For printing), the selector 710 selectively outputs the data in the shift register 708 and outputs the data to the print data transfer circuit 109. The shift register 709 is configured to shift data in the direction from LSB to MSB (from the lower end to the upper end of the recording head). When printing is performed at the lower end position of the recording material, the selector 710 causes the shift register 709 to shift. The data is selected and output to the print data transfer circuit 109.
[0056]
With the printing process as described above, the shift amount is corrected with respect to the shift in the nozzle arrangement direction between the plurality of head units, and the control for performing the lower end printing of the recording material such as paper is realized. Accordingly, it is possible to maximize the print area of the recording material such as paper, and it is possible to provide a high-quality image without dot deviation even at the lower end of the recording material such as paper.
[0057]
(Other)
The present invention includes means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used for ejecting ink, particularly in the ink jet recording system, and the ink is generated by the thermal energy. In the recording head and the recording apparatus of the type that causes the state change, excellent effects are brought about. This is because such a system can achieve high recording density and high definition.
[0058]
As for the typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid and, as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable that the drive signal has a pulse shape, since the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve discharge of a liquid (ink) having particularly excellent responsiveness. As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.
[0059]
As the configuration of the recording head, in addition to the combination configuration (straight liquid channel or right angle liquid channel) of the discharge port, the liquid channel, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting part The configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose the configuration in which the lens is disposed in the bending region, are also included in the present invention. In addition, for a plurality of electrothermal transducers, Japanese Patent Application Laid-Open No. Sho 59-123670 that discloses a configuration in which a common slit is used as a discharge portion of the electrothermal transducer or an aperture that absorbs pressure waves of thermal energy is provided. The effect of the present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461 which discloses a configuration corresponding to the discharge unit. That is, whatever the form of the recording head is, according to the present invention, recording can be performed reliably and efficiently.
[0060]
Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by the recording apparatus. As such a recording head, either a configuration satisfying the length by a combination of a plurality of recording heads or a configuration as a single recording head formed integrally may be used.
[0061]
In addition, even the serial type as shown in the above example can be connected to the main body of the recording head or attached to the main body of the device so that electrical connection with the main body of the device and ink supply from the main body are possible. The present invention is also effective when a replaceable chip type recording head or a cartridge type recording head in which an ink tank is integrally provided in the recording head itself is used.
[0062]
In addition, it is preferable to add a recording head ejection recovery means, a preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention, since the effects of the present invention can be further stabilized. Specifically, heating is performed using a capping unit, a cleaning unit, a pressurizing or suction unit, an electrothermal transducer, a heating element different from this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.
[0063]
Also, regarding the type or number of recording heads to be mounted, for example, a plurality of recording heads corresponding to a plurality of inks having different recording colors and densities are provided in addition to one provided corresponding to a single color ink. May be used. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be configured by integrally configuring the recording head or by combining a plurality of colors. Alternatively, the present invention is extremely effective for an apparatus having at least one of full-color recording modes by color mixing.
[0064]
In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, ink that is solidified at room temperature or lower and that softens or liquefies at room temperature may be used. In the ink jet system, the temperature of the ink itself is adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within a stable discharge range. A liquid material may be used. In addition, it is solidified and heated in an untreated state in order to actively prevent the temperature rise caused by thermal energy from being used as the energy for changing the state of the ink from the solid state to the liquid state, or to prevent the ink from evaporating. You may use the ink which liquefies by. In any case, by applying thermal energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case of using ink having the property of being liquefied for the first time. The ink in such a case is in a state of being held as a liquid or a solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, the electrothermal converter may be opposed to the electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.
[0065]
In addition, the ink jet recording apparatus according to the present invention may be used as an image output terminal of an information processing device such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function. The thing etc. may be sufficient.
[0066]
【The invention's effect】
According to the present invention described above, in accordance with the displacement of the nozzle arrangement direction of the recording head, Ru can perform correction processing of the data easily.
[Brief description of the drawings]
FIG. 1 is a block diagram of a control system of a serial printer suitable for carrying out the present invention.
FIG. 2 is a detailed block diagram of a print data processing circuit in the first embodiment.
FIG. 3 is an explanatory diagram illustrating how the recording head is used during two-pass printing and four-pass printing in the first embodiment.
FIG. 4 is an explanatory diagram showing correspondence between data on a DRAM and each nozzle of a recording head when two-pass printing is performed in the first embodiment.
FIG. 5 is a timing chart showing timings until data is read from a DRAM and latched in a data latch 204;
FIG. 6 is an explanatory diagram illustrating a method of correcting a deviation between head units according to the first embodiment.
FIG. 7 is a detailed block diagram of a print data processing circuit in the second embodiment.
FIG. 8 is an explanatory diagram showing data processing at the time of bottom-end printing in the second embodiment.
FIG. 9 is a diagram illustrating a positional relationship between a plurality of head units.
FIG. 10 is an explanatory diagram illustrating a method of correcting a deviation between head units in a conventional example.
[Explanation of symbols]
101 Interface 102 Memory 103 ASIC
104 ROM
105 Interface Control Unit 106 Image Conversion Circuit 107 Print Data Processing Circuit 108 Print Timing Control Circuit 109 Print Data Transfer Circuit 110 Recording Head 111 MPU
112 Printer driver 201a, 201b, 201c, 701a, 701b, 701c Register 202a, 202b, 702a, 702b Latch 203, 703 Bit shift circuit 204, 704 Latch 205, 705 Mask pattern generation circuit 206, 706 Mask circuit 207, 707 Shift Clock generation circuit 208, 708, 709 Shift register 710 selector

Claims (8)

With respect to the first recording head and the second recording head, each of which has a nozzle row composed of M nozzles arranged in a predetermined direction, the second recording head is in the predetermined direction with respect to the first recording head. And an image recording apparatus that records the first recording head and the second recording head by scanning the recording material with respect to the recording material.
Memory means for holding data corresponding to the nozzle rows in units of L bits;
First holding means for holding data of 2 × L bits from consecutive addresses along the predetermined direction with respect to the memory means;
2 × L bits of data held in the first holding means are input, and based on the difference between the L-bit unit data boundary held by the memory means and the data boundary used in printing for each scan. after shifting Te, a first shift output means for outputting the L-bit data,
Second holding means for sequentially inputting data for L bits output by the first shift output means, and holding M bit data corresponding to the M nozzles ;
Second shift output means for shifting and outputting the M bit data held by the second holding means in accordance with a deviation of N nozzles in the predetermined direction;
An image recording apparatus comprising: transfer means for transferring the M-bit data output from the second shift output means to the second recording head .   The second shift output means includes shift output means for shifting the M-bit data toward the downstream side in the conveyance direction of the recording material, and shift output means for shifting toward the upstream side in the conveyance direction. The image recording apparatus according to claim 1.   2. The apparatus according to claim 1, further comprising data extraction means for extracting valid data of the M-bit data according to the number of passes when multipass printing is performed by the first recording head and the second recording head. Item 3. The image recording apparatus according to Item 1 or 2.   The image recording apparatus according to claim 1, further comprising a shift number setting unit that sets an amount of shifting by the first shift output unit.   The image recording apparatus according to claim 1, further comprising a mask unit that masks a part of the M bit data in accordance with the deviation of the N nozzles. The image recording apparatus according to claim 1, wherein the first holding unit reads data from the memory unit in units of L bits . 2. The image recording apparatus according to claim 1, wherein the L-bit unit reading of the first holding unit and the L-bit data output of the first shift output unit are performed based on the same clock signal . The image recording apparatus according to claim 1, wherein the data corresponding to the nozzle row is data obtained by sequentially converting line data in the main scanning direction in the sub-scanning direction .

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