JPH03234668A - Recording device and driving method for recording head - Google Patents

Abstract

PURPOSE:To make the difference in shifted pattern of dots uniform and obtain a favorable recording grade by setting the sequence of drivings for a time- division driving device in response to the direction of movement of a recording head and/or in response to a range of recording elements to be used for recording among a plurality of recording elements. CONSTITUTION:Accompanying with the movement of a carriage to the right, dots are recorded in such a manner that the right side of dots becomes lower. On the contrary, when recording to the left is performed without changing the driving sequence of driving signals H1-H4, the left side of dots becomes lower, and the directions of the slip of dots are recorded to be different. In order to correct this, for recording to the left, the driving sequence for driving signals is made such as H4, H3, H2, H1. Thus, when recording to the right is performed by the driving sequence of driving signals, i.e., the driving sequence of division blocks such as (a), (b), (c), (d), for recording to the left, driving is performed by the sequence of (d), (C), (b), (a), and by this method, even in the case of both direction recording, shifted patterns of dot become the same.

Description

[Problem to be solved by the invention]

However, when time-division driving is performed as the print head moves in the main scanning direction as described above, the dots printed by the ejection ports arranged in the sub-scanning direction of the print head are originally one in the sub-scanning direction. Where it should be arranged in columns,
When viewed microscopically, dot rows are recorded obliquely in each block, or the dot rows are shifted from block to block and recorded obliquely as a whole, resulting in so-called dot misalignment. In particular, in the bubble jet method, the pulse width of the drive pulse for driving the recording head, that is, the pulse application time is l.
Since it is relatively short, less than Oμsec, the driving frequency can be increased, and the carriage speed can be increased accordingly. For this reason, the above-mentioned dot misalignment becomes particularly noticeable when a bubble jet recording head is used. As described above, when time-division driving is performed in a serial type recording apparatus, the above-mentioned dot misalignment is unavoidable, and in this case, the following problems particularly occur. In other words, some printing devices perform bidirectional printing in order to improve throughput, and in this case, the scanning direction of the printhead is changed such that when printing in the right direction, the print head goes down to the right, and when printing in the left direction, it goes down to the left. The deviation of the dot rows differs depending on the Therefore, even if the same pattern is printed, the printing results will differ depending on the scanning direction. The same thing can be said when recording dots in a bidirectional manner such as in full-color recording. Also, depending on the recording device, fine adjustment of the recording area may be performed using ejection ports arranged at minute intervals. Recording may be performed limited to M (M<N). In this case, depending on how the ejection ports are selected, the dot row may start or end in the middle of the block at both ends of the dot row recorded by the entire limited ejection ports. In this way, even if an attempt is made to record the same pattern, microscopically, the recorded dot pattern will have several patterns depending on the selected ejection port. The secondary disadvantage of time-division driving that occurs during bidirectional printing or printing with limited ejection ports, as described above, is that the dot misalignment described above is inconsistent, which impairs the quality of the printing result and This causes instability in the quality of the recorded results. The present invention has been made in view of the above problems, and
The purpose of this is to change the order of the blocks to be driven when time-divisionally driving the recording head depending on the scanning direction and the limited ejection ports, thereby making the dot misalignment constant and achieving a good print quality. An object of the present invention is to provide a recording device and a recording head driving method that can obtain high recording quality. [Means for Solving the Problems] To this end, the present invention provides a recording apparatus that includes a recording head disposed with a plurality of recording elements and performs recording as the recording head moves. A time-division driving means for dividing the element into a plurality of recording element groups and driving the plurality of recording element groups in a time-division manner, and a driving order in the time-division driving means in the direction of movement of the recording head and/or The present invention is characterized by comprising a drive order setting means for setting a range of recording elements to be used for recording among the plurality of recording elements. In addition, in a method of driving a recording head in which a plurality of recording elements are disposed and recording is performed as the recording elements move, a method for driving a recording head that corresponds to each of a plurality of recording element groups obtained by dividing the plurality of recording elements is provided. setting the transfer order of the drive signals to be transferred according to the direction of movement of the recording head and/or the range of recording elements to be used for recording among the plurality of recording elements;
The plurality of recording element groups are sequentially driven by transferring the drive signals in accordance with the set order.

[For use]

According to the above configuration, when a print head having a plurality of print elements is time-divisionally driven for each divided element group, the order of the time-division drive is determined by the scanning direction of the printhead and the range of the print elements used for printing. It will be set accordingly. Thereby, it is possible to always keep the pattern of dot misalignment that occurs inherently in time-division driving associated with movement of the recording head to be a constant pattern. [Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic perspective view showing essential parts of an inkjet recording apparatus according to an embodiment of the present invention. In Fig. 1, reference numeral 1 denotes a recording head that has 64 ejection ports arranged in the sub-scanning direction, and a liquid path communicating with each ejection port has an electric heater that generates thermal energy used to eject ink. A conversion element is provided. Reference numeral 2 denotes a carriage on which a recording head is mounted and reciprocated along a guide shaft 3 by a drive means (not shown) such as a carriage motor. 4 is
The recording surface of the recording sheet 5 as a recording medium is moved to the recording head 1.
This conveyance roller functions as a platen held at a position facing the ejection opening of the recording sheet 5, and conveys the recording sheet 5 in the direction of the arrow in the figure, which is rotatably driven by a drive means (not shown) such as a paper feed motor. FIG. 2 is a block diagram showing the control structure of the recording apparatus shown in FIG. In FIG. 2, 6 is a CPU that executes control related to operations and processing in the recording device, 7 is a ROM that stores programs and various data for the above operations and processing, and 8 is a
RAM 9 is used as an area for temporarily storing data from the host and as a work area for the CPU 6. R.O.
M7. This is a control section composed of a RAM 8 and the like, and is constructed on a board disposed at a predetermined portion of the recording apparatus. lO
is a host device that sends recording data and control codes to the recording device of this example, and is, for example, a microcomputer,
It is configured as a word processor, a document reading section of a copying machine, etc. 11 is a data receiving unit that receives various signals from the host. 12 is a head driver (hereinafter referred to as
(also referred to as a recording head drive circuit), 21 is a drive control circuit to be described later, which controls the drive of the head driver 12 in accordance with a control signal from the control section 9. Reference numeral 14 denotes an information signal input unit, such as a keyboard, for inputting control signals to the control unit 9 via the input board 13. Reference numeral 16 denotes a drive unit driven by a control signal transferred from the control unit 9 via the output boat 15. It consists of a paper feed motor etc. FIG. 3 is a block diagram showing details of the head driver 12 shown in FIG. 2. In FIG. 3, reference numeral 18 denotes a latch circuit for sequentially storing serially transferred recording data, holding this data in response to a latch signal, and outputting it after recording. Reference numeral 19 denotes an AND gate, which is provided corresponding to each of the electrothermal transducers R1 to R64 of each discharge port. Corresponding recording data output from the latch circuit 18 is input to one input terminal of the AND gate 19 . The other end of the AND gate 19 is manually supplied with one of the drive signals H1 to H4. Here, the drive signal H1 is the ejection port number l, 5°9,...
, 1+4(k-1), . . .61 are input to the corresponding AND gate 19. Hereinafter, the drive signal H2 is similarly applied to ejection port numbers 2, 6, . ..., 2+4(k-1), ...,
The drive signal H3 is sent to the AND gate 19 corresponding to the discharge port number 3°7, . . . , 3+4(k-11, . . .
, 63, and the drive signal H4 is input to the AND gates 19 corresponding to ejection port numbers 4, 8°4+4 (k-IL..., 64).In this configuration, the drive signal H1 Time-division driving is performed by sequentially setting H4 to "1". Reference numeral 20 denotes a drive element made of, for example, a transistor, which operates in accordance with the output of each AND gate 19, thereby causing electrothermal conversion elements R1 to R64. A drive pulse is applied to each. The following will explain the case where 64 ejection ports are driven in four parts, that is, the case where each block of 16 ejection ports is driven. Note that the drive signal On the other hand, if the ejection ports that are driven have periodicity, the present invention can be applied.For example, when driving every y ejection ports in X-divided drive, or in the case of X-divided drive, A case may be considered in which y consecutive ejection ports are regarded as one block and the ejection ports are driven every , a case will be described in which the recording head is driven to be the same for rightward recording and leftward recording. Normally, the drive signals H4 to H4 are the old, H2, H3, and H4 as shown in FIG. 7, for example. Therefore, when rightward recording is performed, dots are recorded downward to the right as the carriage 2 moves to the right, as shown in FIG. Signal H1-84
If recording is performed in the left direction without changing the driving order of the dots, the dots will fall downward to the left as shown in FIG. 5, and the dots will be recorded in a different direction as explained in the conventional example. In order to correct this, the driving order of the drive signals in leftward recording is changed to H4, H3, H2, Hl as shown in FIG. 8, as shown in FIG. As a result, the same pattern of dot displacement as shown in FIG. 4 is obtained. In this way, when recording in the right direction, the drive order of the drive signals, and therefore the drive order of the divided blocks, is set to a, b. When performing in the order of c and d, in the case of leftward recording, d and c
, b, and a, the pattern of dot displacement becomes the same even in bidirectional recording. Note that in this embodiment, the same effect can be obtained regardless of how the electrothermal transducer is connected to the drive signal. For example, the same effect can be obtained by connecting the electrothermal transducer elements of several consecutive ejection ports in the ejection port array with the same drive signal. In this case, the dots printed by the ejection ports of each block are not diagonally arranged but are arranged in the sub-scanning direction, and these arrangements are shifted for each block and are printed diagonally. Table 1 shows the relationship between the recording direction and the driving order in the first embodiment. In this table, Fl is a control signal indicating the recording direction; when Fl is "O", it indicates rightward recording, and when it is "1", it indicates leftward recording. Second Embodiment This example takes as an example the case where printing is performed using 60 consecutive ejection ports out of 64 ejection ports, and by determining the driving order of the blocks according to the selection of the ejection ports, a constant dot is always maintained. An example of obtaining a shift pattern is shown below. When the ejection ports are not used in a limited manner, the recording data of dot 1 is given to the ejection port with ejection port number 1, and assuming that the same applies to the following ejection ports in sequence, by activating the same drive signal, Dots 1, 5, 9, . . . are recorded. Therefore, if the drive signal is driven in the order of old, H2, H3, and H4, when ejection port numbers 1 to 60 are selected, in the case of rightward printing, the pattern shown by A in FIG. 4.5 to 8. ... is recorded downward to the right. On the other hand, for example, if the ejection port No. 61 is selected from the ejection ports No. 2, the recording data of dot 1 is given to the ejection port No. 2, and dot 1 is recorded by activating the drive signal H2. . Therefore, as explained in the example related to the background art, if the drive order of the drive signals is not changed and the drive signals are driven in the order of old, H2, H3, and H4, the pattern shown by B in FIG. 9 is obtained by dots 1 to 3. 4 to 7, 8 to 11, and so on are recorded in a downward direction to the right. As is clear from the recording pattern B shown in FIG. 9, the recording dot row is cut off in the middle of the block at both ends of the recording dot. As shown in FIG. 9, the manner in which the recording dot rows are cut differs depending on the range of the ejection ports used, so the print dot pattern differs depending on the range of the ejection ports used. On the other hand, as shown in FIG.
, H3, H4, Hl, as shown in recording pattern C in Figure 1O, which is the same pattern as in recording range A in Figure 9, dots 1 to 4.5 to 8... are on the right. It is recorded on the decline. If you select the outlet number 3 to outlet number 62, the dots 1, 5, 9 will be placed at outlet 1, 7, and 11 of number 3.
. . . is given, and by activating the drive signal H3, the dot l is generated. 5.9... is recorded. Therefore, in this case, if the drive signals are driven in the order of H3, H4, Hl, and H2, the first
As shown in dot pattern D in Figure 1, one of the dots
From 4, 5 to 8. ... is recorded downward to the right. As described above, when the recording data of dot 1, which is normally set at the first ejection port, is shifted to the second ejection port, third ejection port, etc. due to the selection of the ejection port to be used, If the driving order of the driving signals is also shifted accordingly,
Recording can always be performed with the same dot shift pattern. Table 2 shows the relationship between the shift of the ejection ports and the drive order described above. In this table, Sl and Sl represent control signals indicating the amount of shift of the ejection port, and represent how the drive signal corresponding to the ejection port for the first dot is shifted from H1 to any one of H1 to H4. When the shift destination is Hl, that is, when not shifting, the shift amount is 0 (S1 = S2 = “O”), and in the case of H2,
Shift amount 1 (S1="l", Sl: "O"), shift amount 2 when H3 (S1="O", S2="l"), H
4, the shift amount is 3 (S1=32=“1”). Table 2 The above shift amount signals, that is, drive order selection signals Sl, S
2, the driving order of the driving signals H1 to H4 is determined. Third Embodiment This example shows a case where the first embodiment described above and the second embodiment described above are combined. Here, the first. Since the second embodiment can be considered as mutually independent processes, these processes are summarized as shown in Table 3. ↓ ↓ ↓ ↓ ↓ ↓ ↓ FIGS. 13 to 18 are circuit block diagrams showing configurations for realizing the relationships between selection signals and drive orders shown in Tables 1 to 3. FIG. 13 shows a drive pulse generation circuit 130 configured as a part of the drive control circuit 21 shown in FIG. A signal a for increasing or decreasing the counter value, four driving pulses b, and a signal for increasing or decreasing the counter value every time one driving pulse b is output are output. FIG. 14 is a circuit block diagram of a drive order control circuit according to the first embodiment of the present invention. This order control circuit is also configured in the drive control circuit 21. When the signal a from the drive pulse generation circuit 130 described above is input, the initial value of the binary counter 140 is set. That is, in the case of rightward recording, since the control signal F1 is "O", the initial value of the counter is "00", and UP is selected for the counter. Therefore, depending on the signal, the counter outputs Q, , QB are “0”.
0", "Ol", "lO", and "11". These signals are decoded by the decoder 141, and drive signals are sequentially output in the order of H1, 82, H13, and H4. In the case of leftward recording Since the control signal Fl is "1", the initial value is "11", and Down is selected for the counter. Therefore, the drive signals are output in the order of H4, H3, H2, and old. FIGS. 15 and 16 are circuit block diagrams showing two sides of a drive order control circuit according to a second embodiment of the present invention. In the circuit shown in FIG. 15, the control signals SL and S2 are
In the case of "O", the initial value "00" is loaded into the counter 150, and the drive signals from the decoder 151 are changed to old, H2, H3,
They are output in the order of H4. When S1="l" and S2="O", the initial value "01" is loaded into the counter 150, and the drive signals are output in the order of H2, H3, old, and H2. Similarly, if S1="O" and S2="1", H
3, H4, old, H2 in this order, S1="1", S2="1"
”, )14.Hl, H2, and H3 are output in this order. In the circuit shown in FIG. 16, the initial value set in the counter 160 and the direction of UP/Down are constant;
Therefore, the decoder 161 always outputs Y,,Y,. Output signals in the order of Y, Y4. However, the control signals St, S2 manually input to each of the selectors 162 to 165 are
The signal output from each selector according to (input terminal A,
B, C, D) is set, which causes the signals Y1 to
Drive signals are sequentially output in accordance with Y4 as in the case shown in FIG. FIGS. 17 and 18 are circuit block diagrams showing two sides of a drive order control circuit according to a third embodiment of the present invention. In the circuit shown in FIG. 17, the control signals Sl and S2 set the signals output from each of the selectors 172 to 175, and the control signal F1 sets the signals output from the counter 170.
An initial value is set and an up-count or down-count is selected. In the circuit shown in FIG. 18, control signals Fl and Sl
The signals Sl, S2 . The signals output by selectors 182 and 183 from among SL and S2 are set, and thereby the initial value of counter 180 is set. Further, the up-count or down-count of the counter is set by the control signal F1. The present invention is particularly effective when performing color recording using an inkjet method. This means that when performing color recording using some of the multiple ejection ports of the head provided for each color, if the number of ejection ports used for each head is limited, dot misalignment for each color of ink will occur. This is because although there is a possibility that the patterns may be different, the present invention can solve such a problem. In each of the above embodiments, a recording apparatus using a so-called bubble jet type recording head has been described, but the present invention is not limited to these apparatuses, but can also be applied to inkjet recording apparatuses other than bubble jet type, or The present invention can also be applied to thermal type recording apparatuses such as thermal transfer type and heat sensitive type. (Others) The present invention brings about excellent effects particularly in a bubble jet type recording head and recording apparatus among inkjet recording types. This is because such a system can achieve higher recording density and higher definition. As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and the continuous type, but especially in the case of the on-demand type, it is applicable to the sheet holding the ink and the return trip. generating thermal energy in the electrothermal transducer by applying at least one drive signal corresponding to recorded information and causing a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer disposed at the This is effective because it causes film boiling on the heat-active surface of the recording head, resulting in the formation of bubbles in the ink that correspond one-to-one to this drive signal. The growth and contraction of the bubble causes ink to be ejected through the ejection opening to form at least one drop. It is more preferable to use a pulsed drive signal for this drive signal, since the growth and contraction of bubbles can be carried out immediately and appropriately, making it possible to eject the t-form product (ink) with particularly excellent responsiveness. This pulse-shaped drive signal is described in US Pat. No. 4,463,359 and US Pat.
Those described in US Pat. No. 45,262 are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed. The configuration of the recording head includes a combination configuration of an ejection port, a return path, and an electrothermal converter (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, as well as a heat acting section. US Pat. No. 4,558,333 and US Pat. No. 4,459,600 disclose a configuration in which the
The present invention also includes a configuration using the specification of the above specification. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. Japanese Unexamined Patent Application Publication No. 1983-1989 discloses a configuration corresponding to a discharge part.
The effects of the present invention are also effective even with a configuration based on Publication No. 9-138461. In other words, regardless of the form of the recording head, recording can be performed reliably and efficiently. Furthermore, even the serial type shown above has a replaceable chip-type recording head that can be attached to the main body of the device to enable electrical connection with the main body of the device and supply of ink from the main body of the device, or The present invention is also effective when using a cartridge type recording head that is provided integrally with the recording head itself. Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing. In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there is also a plurality of recording heads that correspond to multiple inks with different recording colors and densities. It may be something that can be done. In addition, the inkjet recording apparatus of the present invention can be used as an image output terminal for information processing equipment such as a computer, or as a copying apparatus combined with a reader or the like, or as a facsimile apparatus having a transmitting and receiving function. It may also be one that takes [Effects of the Invention] As is clear from the above description, according to the present invention, when a print head having a plurality of print elements is time-divisionally driven for each divided element group, the order of the time-division drive is determined by the time-division driving order of the printhead. It is set depending on the scanning direction and the range of printing elements used for printing. Thereby, it is possible to always keep the pattern of dot misalignment that occurs inherently in time-division driving associated with movement of the recording head to be a constant pattern. As a result, even when recording is performed in both directions or within a limited range of recording elements by time-division driving, the recording quality can be made good and kept constant.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of an inkjet recording apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing a control configuration of the apparatus shown in FIG. 1, and FIG. FIG. 4 is a conceptual diagram showing the state of dot misalignment during rightward recording according to the first embodiment of the present invention, and FIG. 5 is a circuit block diagram showing a recording head drive circuit according to the background art. FIG. 6 is a conceptual diagram showing an example of dot misalignment during recording, and FIG. 6 is a conceptual diagram showing an example of dot misalignment during leftward recording according to the first embodiment of the present invention. FIG. An example of a timing chart of such a drive signal, FIG. 8 is a timing chart of a drive signal according to the first embodiment of the present invention, and FIG. 10 and 11 are conceptual diagrams illustrating the dot misalignment according to the second embodiment of the present invention, respectively, and FIG. 12 is a conceptual diagram showing the driving signal according to the second embodiment of the present invention. FIG. 13 is a conceptual diagram showing the operation mode of the drive pulse generation circuit according to the first embodiment of the present invention, and FIG. 14 is a timing chart showing an example of the drive sequence control circuit according to the first embodiment of the present invention. FIGS. 15 and 16 are circuit block diagrams showing a drive order control circuit according to a second embodiment of the present invention, and FIGS. 17 and 18 are circuit block diagrams showing a drive order control circuit according to a third embodiment of the present invention, respectively. FIG. 2 is a circuit block diagram showing a drive order control circuit according to an example. 1... Recording head, 2... Carriage, 6... CPU. 7...ROM. 8...RAM. 12... Head driver (recording head drive circuit), 21... Drive control circuit, 130... Drive pulse generation circuit, 140, 150.160.170.180... Counter, 141, 151.161. 17.181...decoder, 162, 163.164.165.172.17
3.174.175.182.183゜...Selector, Fl, SL, S2...Control signal, old, 82. l (3, 84... Drive signal. Figure 3 Figure 5 Figure Figure 5 Figure Figure (1) (2) (31 (4) (G, G) 111 )-IHH)-1 (Kokuho Poetry'2341 (Kutn) I CI) (2) (3) + 4>Figure 10 Niko Sho 1) (J1 Odonto) 111 HHHH (3mukai fortune-telling '3412 (Kori-do Yokotan 1 (1>+2) (3)+4) 4 yarn・l
Figure 11

Claims (1)

[Scope of Claims] 1) A printing apparatus that includes a print head disposed with a plurality of print elements and performs printing as the print head moves, the plurality of print elements being divided into a plurality of print element groups. and a time-division driving means for time-divisionally driving the plurality of recording element groups, and a driving order in the time-division driving means according to the direction of movement of the recording head and/or the direction of the recording among the plurality of recording elements. 1. A printing apparatus comprising: drive order setting means for setting a drive order according to a range of printing elements to be provided. 2) The drive order setting means reverses the transfer order of drive signals transferred to each of the plurality of recording elements in the time division drive means in one direction and the other direction of movement of the recording head. 2. The recording apparatus according to claim 1, wherein the recording apparatus is set in the following order. 3) The drive order setting means sets the transfer order of drive signals to be transferred to each of the plurality of recording element groups in the time division drive means according to the range of recording elements to be used for recording. The recording device according to claim 1, wherein the recording device shifts. 4) The recording element has an ejection opening for ejecting ink droplets, a liquid path communicating with the ejection opening, and an electrothermal conversion element for causing film boiling in the ink in the liquid path. 4. The recording device according to claim 1, wherein: 5) In a recording head driving method for disposing a plurality of recording elements and performing recording as the recording elements move, a method for driving a recording head that corresponds to each of a plurality of recording element groups obtained by dividing the plurality of recording elements. The transfer order of drive signals transferred by
The driving signals are set according to the direction of movement of the recording head and/or the range of recording elements to be used for recording among the plurality of recording elements, and the driving signals are transferred in accordance with the set order. A method for driving a recording head, comprising sequentially driving a group of recording elements. 6) The recording head driving method according to claim 5, wherein the transfer order of the driving signals is set to be opposite to each other in one direction and the other direction of movement of the recording head. 7) The recording head driving method according to claim 5, wherein the transfer order of the drive signals is set by shifting according to the range of recording elements used for the recording. 8) The recording element has an ejection opening for ejecting ink droplets, a liquid path communicating with the ejection opening, and an electrothermal conversion element for causing film boiling in the ink in the liquid path. 8. The method of driving a recording head according to claim 5.