JP3227241B2 - Ink jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for performing recording by discharging ink from a recording head to a recording material, and more particularly to an ink jet recording apparatus for controlling the driving of a recording head.

[0002]

2. Description of the Related Art Recording devices such as printers, copiers, and facsimile machines are configured to record an image composed of dot patterns on a recording material such as paper or a plastic thin plate based on image information. I have.

[0003] The recording apparatus can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type and the like according to a recording system. An ink (recording liquid) droplet is ejected and ejected from an ejection port of a recording head, and is adhered to a recording material to perform recording.

[0004] In recent years, a large number of recording apparatuses have been used, and high-speed recording, high resolution, high image quality, low noise, and the like have been required for these recording apparatuses. The above-mentioned ink jet recording apparatus can be cited as a recording apparatus that meets such demands. In this inkjet recording apparatus, non-contact printing is possible because recording is performed by discharging ink from the recording head, and therefore, a very stable recorded image can be obtained.

However, in the ink jet recording system, various inconveniences of hydrodynamics occur when the recording head is used at or above the limit printing speed in order to handle ink which is a fluid. Further, since ink is a liquid, its physical state, such as viscosity and surface tension, always fluctuates greatly depending on the environmental temperature and the standing time of the ink. For this reason, even if printing is possible in a certain state, printing may become difficult due to an increase in negative pressure due to a decrease in the ambient temperature or the remaining amount of ink in the ink tank, or the like.

Conventionally, there have been many attempts to discharge all of the plurality of nozzles in as short a time as possible so that vertical ruled lines can be printed as linearly as possible. Therefore, in most cases, several tens of nozzles are collectively discharged to some extent from several nozzles to about ten nozzles at the same time to shorten the time as much as possible. In this way, when the ink is used near the limit ejection cycle, the ink cannot be refilled (refilled) into the nozzle in time, and the next ejection starts before the ink is refilled. The situation will be reduced to In particular, when a large number of nozzles are discharged in a short time, the negative pressure level in the common liquid chamber temporarily becomes extremely high, so that refilling cannot be performed in time or large vibrations occur, causing ink to rise from the nozzle surface. Since the next ejection starts, the ejection becomes a splash-like ejection, and in the past, a problem often occurred.

As a countermeasure, by preventing ink from being simultaneously ejected from adjacent ejection ports, the degree of freedom in the inflow direction of ink flowing from the common liquid chamber toward the nozzles is increased, and the ink supply amount to the nozzle entrance is increased. Of the present invention has the effect of simultaneously increasing
No. 411.

[0008] According to this control, it is possible to obtain a damping effect of the vibration and an improvement of the refill speed due to the pulsation by the phase difference of the vibration at the adjacent nozzle. Particularly, the effect of improving the refill of other nozzles by the discharge reaction pressure wave is very large.

There are two major factors in the improvement by the discharge reaction pressure wave. One is to discharge the other nozzles, preferably the adjacent nozzles, to the nozzles that have just completed the discharge, that is, the nozzles before the ink in the nozzles are discharged and reach the maximum meniscus retreat amount, and apply a reaction pressure wave to the maximum meniscus. An object of the present invention is to attenuate the inertial force of the ink to retreat before reaching the retreat amount. As a result, the effect of shortening the distance that must be refilled can be obtained, and the refill time can be shortened.

Another effect is to obtain the effect of increasing the refill speed itself by applying a large number of ejection reaction pulses to the refilling nozzle after reaching the maximum meniscus retreat amount. Hereinafter, the above-described driving method is referred to as “shift driving”.

As the shift driving means, there is a shift driving means which shifts the drive timing every other dot and divides the nozzles into even nozzles and odd nozzles, and also a shift drive means which shifts the drive timing every plural dots such as every two dots. .

[0012]

However, in the shift driving method, although the time required for completing the refill is greatly reduced and high-frequency driving is enabled, one of the even-numbered dots and the odd-numbered dots is rarely performed. The recording dot has a phenomenon that the ejection failure occurs. Specifically, when the even-numbered nozzle is driven after the completion of the driving of the odd-numbered nozzle, the ejection of the odd-numbered nozzle becomes defective. Discharge tends to be poor. In other words, in rare cases, the ejection of the first-shot nozzle becomes defective during the shift driving.

[0013] The present invention solves the above-mentioned problems, and performs a shift control to perform high-frequency driving using a fluid pressure wave while performing a drive control for realizing high-frequency driving. It is an object of the present invention to provide an ink jet recording apparatus capable of performing high-speed and high-quality image recording by solving the problem described above.

[0014]

According to the present invention, there is provided a recording head having a plurality of ejection sections for ejecting ink, and a common liquid chamber for supplying ink to the plurality of ejection sections. Of the plurality of ejection units of the print head, a driving unit that ejects ink from an adjacent ejection unit non-simultaneously and one of the adjacent ejection units that performs the non-simultaneous ejection operation ejects ink in advance. A drive control means for switching the discharge from the discharge unit to the subsequent discharge and switching the discharge from the discharge unit that performs the discharge to the other of the adjacent discharge units to the preceding discharge.

[0015]

According to the above-mentioned structure, it is possible to prevent the ejection failure of the first-shot nozzle, which is rarely caused, which is an adverse effect of alternate hitting, and to reduce the maximum refill amount of refill and reduce the refill speed, which are the effects of alternate hitting. In addition, it is possible to prevent the ejection failure of the first-shot nozzle while realizing the effect of speeding up the printing, and to realize high-speed printing and high image quality.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an ink jet recording apparatus according to an embodiment of the present invention.

FIGS. 1 to 5 show a preferred ink jet unit IJU, an ink jet head IJH, an ink tank IT, an ink jet cartridge IJC, an ink jet recording apparatus main body IJRA, and a carriage HC to which the present invention is applied or applied. FIG. 7 is an explanatory diagram for explaining the respective relationships. Hereinafter, the configuration of each unit will be described with reference to these drawings.

(I) Schematic description of the apparatus main body FIG. 1 shows an ink jet recording apparatus I to which the present invention is applied.
FIG. 2 is a schematic view of JRA. In FIG.
13 and the driving force transmission gears 5011 and 5
The carriage HC that engages with the spiral groove 5004 of the lead screw 5005 rotating via 009 has a pin (not shown) and is reciprocated in the directions of arrows a and b.
The carriage HC is equipped with an ink cartridge IJC. 5002 is a paper presser plate,
The paper is pressed against the platen 5000 in the carriage movement direction. Reference numerals 5007 and 5008 denote home position detecting means for confirming the presence of the carriage lever 5006 in this region and switching the rotation direction of the motor 5013. Reference numeral 5016 denotes a member for supporting a cap member 5022 for capping the front surface of the recording head. Reference numeral 5015 denotes suction means for suctioning the inside of the cap, and recovering the suction of the recording head through the opening 5023 in the cap. Reference numeral 5017 denotes a cleaning blade.
Reference numeral 19 denotes a member which enables the blade to move in the front-rear direction, and these members are supported by a main body support plate 5018.
It goes without saying that the blade is not limited to this form, and a well-known cleaning blade can be applied to this embodiment. Also, 50
Reference numeral 12 denotes a lever for starting suction for suction recovery, which moves with the movement of the cam 5020 engaging with the carriage, and the driving force from the drive motor is controlled by a known transmission means such as clutch switching. .

These capping, cleaning, and suction recovery are configured so that when the carriage comes to the home position side area, desired processing can be performed at the corresponding positions by the action of the lead screw 5005. If the desired operation is performed at the timing described above, any of the embodiments can be applied.

Ink cartridge IJ in this embodiment
C, as can be seen from the perspective view of FIG. 2, has a large ink storage ratio, and has a shape in which the tip of the ink jet unit IJU projects slightly from the front surface of the ink tank IT. The inkjet cartridge IJC is fixedly supported by positioning means and electrical contacts, which will be described later, of a carriage HC (FIG. 1) mounted on the inkjet recording apparatus main body IJRA, and is attached to and detached from the carriage HC. Possible types.

(Ii) Description of the structure of the ink jet unit IJU In the ink jet unit IJU, recording is performed using an electrothermal converter that generates thermal energy for causing film boiling to occur in ink in response to an electric signal. Is a unit.

In FIG. 2, reference numeral 100 denotes a plurality of electrothermal transducers (discharge heaters) arranged in a plurality of rows on a Si substrate, and electrical wiring of Al or the like for supplying electric power thereto, formed by a film forming technique. It is a heater board composed of:

Reference numeral 200 denotes a wiring board for the heater board 100. When a wiring corresponding to the wiring of the heater board 100 (for example, connected by wire bonding) is located at an end of the wiring and receives an electric signal from the main unit. And a pad 201.

Reference numeral 1300 denotes a grooved top plate provided with a partition for dividing a plurality of ink flow paths and a common liquid chamber, etc., and an ink receiving port 1500 for receiving ink supplied from an ink tank and introducing the ink into the common liquid chamber. And an orifice plate 400 having a plurality of discharge ports. Polysulfone is preferred as these integrally molded materials,
Other molding resin materials may be used.

Reference numeral 300 denotes a support made of, for example, metal which supports the back surface of the wiring board 200 in a plane, and serves as a bottom plate of the ink jet unit. Reference numeral 500 denotes an M-shaped pressing spring which presses the common liquid chamber at the center of the M-shape,
At 01, a part of the liquid path is pressed with a linear pressure. Heater board 10
0 and the top plate 1300 and the foot of the spring
By being engaged with the back side of the support body 300 through the hole 3121 of the support board 300, the two are engaged with each other in a state where they are sandwiched, so that the urging force of the pressing spring 500 and the front drooping portion 501 causes the heater board 100 The top plate 1300 is fixed by crimping. Further, the support 300 is provided with the ink tank IT 2.
Positioning protrusions 1012 and positioning holes 31 that engage with positioning and heat fusion holding protrusions 1800 and 1801.
2,1900,2000
Positioning projections 2500 for the carriage HC,
2600 on the back side. In addition, the support 300 also has a hole 320 that can penetrate an ink supply pipe 2200 (described later) that allows ink to be supplied from the ink tank. The attachment of the wiring board 200 to the support 300 is performed by sticking with an adhesive or the like. The recesses 2400 and 2400 of the support 300 are respectively provided with the positioning projections 2.
It is provided in the vicinity of 500 and 2600.

The cover member 800 forms the outer wall of the ink jet cartridge IJC and also forms a space for accommodating the ink jet unit IJU. The ink supply member 600 is provided with the ink supply pipe 2200 described above.
Is formed as a fixed cantilever on the supply pipe 2200 side, and a sealing pin 602 for securing a capillary phenomenon between the fixed side of the ink pipe and the ink supply pipe 2200 is inserted. Reference numeral 601 denotes a packing for connecting and sealing the ink tank IT and the supply pipe 2200, and 700 denotes a filter provided at the tank side end of the supply pipe.

(Iii) Description of Ink Tank IT Configuration In the ink tank, the cartridge body 1000, the ink absorber 900, and the ink absorber 900 are inserted from the side of the cartridge body 1000 opposite to the unit IJU mounting surface. It is composed of a lid member 1100 for sealing this.

Reference numeral 900 denotes an absorber for impregnating the ink, which is arranged in the cartridge body 1000. 1
200 is a unit IJ consisting of the above parts 100 to 600
U is a supply port for supplying ink to U, and the unit is
It is also an injection port for performing ink impregnation of the absorber 900 by injecting ink from the supply port 1200 in a process before the arrangement at 010.

In this embodiment, the ink supply portions are the air communication port and the supply port, but the rib 2300 in the main body 1000 and the cover member for improving the ink supply from the ink absorber. 1100 partial rib 2302, 2
301 and the air presence area in the tank formed by
The ink supply port 12 is continuously connected from the air communication port 1401 side.
Since the configuration is formed over the corner region farthest from 00, it is important that relatively good and uniform ink supply to the absorber is performed from the supply port 1200 side. This method is extremely effective in practice. The rib 2300 has four ribs parallel to the carriage movement direction on the rear surface of the main body 1000 of the ink tank, and prevents the absorber from sticking to the rear surface.
Also, the partial ribs 2302 and 2301 are similarly
Although it is provided on the inner surface of the lid member 1100 which is on an extension corresponding to 0, it is in a divided state unlike the rib 2300, so that the air existence space is increased from the former. Note that the partial ribs 2302 and 2301 are
00 are distributed on a surface that is less than half of the total area of 00. With these ribs, the ink in the corner region farthest from the tank supply port 1200 of the ink absorber could be more stably guided to the supply port 1200 side by capillary force. Reference numeral 1401 denotes an atmosphere communication port provided in the lid member for communicating the inside of the cartridge with the atmosphere. Reference numeral 1400 denotes a liquid-repellent material disposed inside the atmosphere communication port 1401;
This prevents ink from leaking from the air communication port 1401.

The above-described arrangement of the ribs is particularly effective because the ink storage space of the above-described ink tank IT has a rectangular shape and has long sides on the side surfaces. In the case of having a side or a cube, by providing a rib on the entire lid member 1100, the ink supply from the ink absorber 900 can be stabilized.

The ink tank IT has a shape surrounding the unit IJU except for the lower opening by covering the unit IJU with the lid 800 after the unit IJU is mounted. However, the ink cartridge ITJ is mounted on the carriage HC as the ink cartridge IJC. Because the lower opening to perform is close to the carriage HC,
A substantial four-sided surrounding space is formed. Therefore, the heat generated from the head IJH in the surrounding space is effective as a heat retaining space in the space, but the temperature rises slightly for long-term continuous use. For this reason, in this example, a slit 1700 having a width smaller than this space is provided on the upper surface of the cartridge IJC in order to assist the natural heat radiation of the support, and the temperature distribution of the entire unit IJU is uniform while preventing the temperature rise. Was made independent of the environment.

When assembled as an ink cartridge IJC, the ink is supplied from the inside of the cartridge to the supply tank 1200 through the supply port 1200, the hole 320 provided in the support 300, and the introduction port provided on the inside and back side of the supply tank 600. After passing through the inside, an appropriate supply pipe and an ink inlet 15 of the top plate 1300 are provided from the outlet.
00 and flows into the common liquid chamber. A packing made of, for example, silicon rubber or butyl rubber is provided at the connection portion for ink communication described above, whereby sealing is performed to secure an ink supply path.

(Iv) Description of the Heater Board FIG. 3 is a schematic view of the heater board 100 of the head used in this embodiment. A temperature control (sub) heater 8d for controlling the temperature of the head, a discharge section array 8g provided with a discharge (main) heater 8c for discharging ink, and a drive element 8h are positioned as shown in FIG. In relation, they are formed on the same substrate. By arranging each element on the same substrate in this manner, the head temperature can be detected and controlled efficiently, and the head can be made compact and the manufacturing process can be simplified. Also, FIG. 7 shows the positional relationship of the outer peripheral wall cross section 8f of the top plate, which is separated into a region where the heater board is filled with ink and a region where the heater board is not filled. The discharge heater 8d side of the outer peripheral wall section 8f of the top plate functions as a common liquid chamber. A liquid passage is formed by a groove formed on the discharge section row 8g of the outer peripheral wall section 8f of the top plate.

(Vi) Description of Control Configuration Next, a control configuration for executing recording control of each section of the above-described apparatus configuration will be described with reference to a block diagram shown in FIG. In FIG. 1 showing a control circuit, 10 is an interface for inputting a recording signal, 11 is an MPU, 12
Reference numeral denotes a program ROM for storing a control program executed by the MPU 11, and reference numeral 13 denotes a dynamic RAM for storing various data (such as the recording signal and recording data supplied to the head). A gate array 14 controls supply of print data to the print head 18, and also controls data transfer between the interface 10, the MPU 11, and the RAM 13. Reference numeral 20 denotes a carrier motor for transporting the recording head 18, and reference numeral 19 denotes a transport motor for transporting the recording paper. Reference numeral 15 denotes a head driver for driving the head, and reference numerals 16 and 17 denote motor drivers for driving the transport motor 19 and the carrier motor 20, respectively.

FIG. 5 is a circuit diagram showing the details of each part of FIG. The gate array 14 includes a data latch 141, a segment (SEG) shift register 142, a multiplexer (MPX) 143, a common (COM) timing generation circuit 144, and a decoder 145. Recording head 18
Has a diode matrix configuration, and a drive current flows through the ejection heaters (H1 to H64) where the common signal COM and the segment signal SEG coincide, whereby the ink is heated and ejected.

The decoder 145 decodes the timing generated by the common timing generation circuit 144 and selects one of the common signals COM1 to COM8. The data latch 141 latches the recording data read from the RAM 13 in 8-bit units, and the multiplexer 143 stores the recording data in the segment shift register 1.
In accordance with 42, it is output as segment signals SEG1-8. The output from the multiplexer 143 can be variously changed according to the contents of the shift register 142 in 4-bit units as described later.

The operation of the above-described control structure will be described. When a recording signal enters the interface 10, the recording signal is converted between the gate array 14 and the MPU 11 into recording data for printing. Then, the motor drivers 16 and 17 are driven, and the recording head is driven according to the recording data sent to the head driver 15 to perform printing. At this time, since the head side has a diode matrix as shown in FIG. 5, the common signal COM. And the segment signal SEG. The pulse current flows through the ejection heaters (H1 to H64) where the values match, and the ink is heated and ejected. Here, the heaters H1 to H64 are connected to the common side and the segment side in 8-bit units.
The segment signal SEG. Are started at the same time, the timing chart is as shown in FIG.
M. 1 rises and SEG. The nozzle whose signal has risen starts discharging. That is COM. 2, CO
M. 3 to COM. Repeated in a short time until 8
The discharge of the nozzle is completed.

(Embodiment 1) In this embodiment, the shift drive is performed to drive the print head at high speed. Hereinafter, the concept of shift control and the details of the means in this embodiment will be specifically described with reference to the drawings.

FIG. 8 (A) shows the case where the discharge reaction pressure wave shown in FIG. 8 (B) is received many times, and the case where FIG. 8 (C) itself does not receive any reaction pressure wave. It shows the behavior of the meniscus receding amount. According to this, it can be seen that the maximum meniscus retreat amount is smaller when the ejection reaction pressure wave is received, and the refill speed is faster because the refill (ink refill) curve is steep.

The maximum meniscus retreat amount is usually determined by the negative pressure level in the common liquid chamber and the impedance design value of the nozzle. However, if the momentary positive pressure wave generated by the reaction of the discharge toward the common liquid chamber by the discharge at the next timing within the same continuous discharge cycle is applied before reaching the maximum meniscus retreat point, the momentary The meniscus which has been retreated at high speed in the nozzle by the inertia force of the ejection reaction by the strong pressure wave loses the inertia force by the impact, and the maximum retreat position becomes shallow.

Next, the refill speed is normally determined by the negative pressure level in the common liquid chamber and the impedance design value of the nozzle. However, the momentary positive pressure wave generated by the recoil of the discharge toward the common liquid chamber due to the discharge after the next timing in the same continuous discharge cycle is also received many times during refilling. Increase refill speed.

From this point of view, let us look at the meniscus retreat fluctuation with and without the shift drive. FIG. 7 shows an example without shift drive. In FIG. 7B, the nozzle 1 of COM1, the nozzle 9 of COM2, the nozzle 17 of COM3,
It can be seen that the maximum meniscus retreat amount and the refill speed gradually change with the nozzle 57 of COM8. Those discharged at the timing of COM1 have the highest refill speed because they receive all the discharge reaction pressure waves from the initial refill to the subsequent discharge. COM2, COM3, C
As the number of nozzles in the latter half of OM8 increases, the number of ejection reaction pressure waves received at the beginning of refilling decreases, and the refilling speed decreases. Further, as for COM8, the maximum amount of meniscus retreat is also maximized, so that a further refill time is required.

On the other hand, in this embodiment, the shift drive shown in FIG. 9 is performed. In this example, the timing of the segment signal SEG is shifted so that adjacent nozzles do not discharge simultaneously. Further, since the common signal COM is originally shifted, the discharge heaters H1 to H64 discharge four nozzles at a time without discharging adjacent nozzles. FIG.
(B) shows the maximum meniscus retreat amount of the nozzle for each common in the figure. As is clear from the figure, unlike the case where the shift drive is not performed, the nozzle driven by each common is different. It was found that there was no difference in the meniscus retreat amount, and the nozzles driven by COM8, which is the final drive common, were within the range of the allowable meniscus retreat amount.

As described above, in this embodiment, by performing the shifting drive, the refilling of the ink to the nozzles is actively supported, and a control means that responds to the recent demand for high-speed printing apparatuses is realized.

However, in the case of the shift driving means, the ejection failure of the first-shot nozzle rarely occurs. Therefore, in the following, how to cause adverse effects by the shift control means,
A result of studying the method of eliminating the adverse effects will be described, and a control means for preventing the above-mentioned adverse effects of the shift control means and extracting only the effects will be described below.

As a representative example of the manner of occurrence of a discharge failure which is an adverse effect of the shift control means, as a result of an experiment, the dot diameter of the previously ejected dot is reduced by about 10 to 20% as compared with the normal dot diameter. -What was originally a single dot was a so-called splash-like print of a collection of multiple small dots. Also, the adverse phenomena are:-Once recurred, they tend to persist over several copies.

The higher the printing duty such as solid printing, the higher the frequency of the adverse effects.

As described above, an adverse effect appears on the first-stroke side of the even-numbered nozzle or the odd-numbered nozzle. However, the adverse effect is eliminated as soon as the printing is performed by changing the way of striking (the relationship between first-strike and second-stroke).

If the applied energy is increased by setting the applied pulse longer or increasing the applied voltage, the problem can be solved. The fact was confirmed.

Based on the above-mentioned defect phenomenon (appearance) and countermeasure effects, the present inventor has assumed that the direct cause of the problem is insufficient applied energy. Although the above phenomena and countermeasure effects can be explained without contradiction by this assumption, there remains a problem as to what principle the shortage of applied energy to the first-shot nozzle occurs due to the shift driving. Since the above-mentioned failure phenomenon does not occur at the time of initial printing, it can be determined that the minimum energy level required for ejection of the first-shot nozzle is increased by performing the shift driving.

For the purpose of confirming the increase in the energy level, a comparison was made between the minimum energy levels at which regular dots can be ejected before and after the occurrence of a defect. I got

In order to investigate the cause of the increase in the energy level, the following confirmation and examination were performed using the head in which the above-mentioned defect occurred.

There was no change in the resistance value of the discharge heater before and after the occurrence of the defect.

No abnormality was observed when the heater surface was observed with a metal microscope.

(Eyepiece; 3.5 × / substantial lens 60)
-No difference was observed in the applied voltage value / current value and the rise / fall characteristics of the pulse between the first hit and the second hit.

To summarize the above results, there is no difference in the input energy to each of the heaters for post-strike and pre-strike due to the shift drive, and there is no difference in the electrothermal conversion efficiency. From the gas phase). That is, a difference may occur in the thermal conductivity from the heater to the ink near the heater, and once the difference occurs, the difference is continued for a while.

As described above, in order to increase the speed of refilling, which is the effect of the shift driving, before the maximum meniscus retreats after ejection and foaming, the effect of heating the nozzles before and after the relevant nozzle to stop the meniscus retreat is reduced; There are two different actions to improve the refill speed by heating the nozzles before and after the relevant nozzle before retreating the maximum meniscus after the refill start discharge foaming. Although it is difficult to completely explain the cause of the failure at this stage, the timing of foaming of alternate hitting differs between the first hit and the last hit of the shift drive, and the time of ejection caused by the second hit. From the negative pressure level difference in the common liquid chamber and the like, it can be easily assumed that the dominant rate (dominance) of the above two actions is different between the first-shot nozzle heater and the second-shot nozzle heater. Further, for example, the improvement of the refill speed, which is the effect of the shift drive, may increase the cavitation at the time of bubble defoaming and may damage the heater. The present inventor assumes that the negative effects of the later shot and the recovery of the negative effects have appeared.

From the above results, it has been found that if the input energy is increased, the adverse effect does not appear as a defect phenomenon. However, the increase in the input energy decreases the life of the heater, the heat storage of the recording head, and the energy consumption. Of course (especially when the battery is driven), and it is needless to say that this is a means to be avoided as much as possible.

The present invention is intended to solve the above-mentioned problems and prevent a decrease in recording quality while realizing a high-speed recording apparatus by using the shift driving means. The prevention of the above-mentioned adverse effects is based on the fact that after-driving of the shift drive has an effect of restoring the adverse effects caused by the first hit of the shift drive,
In the present embodiment, recording is performed while switching the driving timing of the first shot and the second shot for each column.

That is, control for switching the pre-driving of the odd-numbered nozzles shown in FIG. 9 and the pre-driving of the even-numbered nozzles shown in FIG. 10 for each column (one column in this example is 1 horizontal × 64 vertical). Means for preventing the above-mentioned adverse effects is achieved by using means. The control of switching between first and last shot is as follows:
SEG shift register 14 in gate array 14 of FIG.
Switching is performed for each column at 2.

FIG. 11 is a circuit diagram showing the details of the SEG shift register 142, which comprises a shift register 1420, a selector 1421, and data registers 1422 and 1423. The shift register 1420 is configured in the form of a ring in which the uppermost output terminal Q1 is connected to the input terminal I,
The selector 1421 selects the data registers 1422 and 1423 for loading the initial value of the shift register 1420 according to the flag signal input to the selection terminal S. When the data register 1422 is selected, the initial drive is an odd-numbered nozzle, and when the data register 1423 is selected, the initial drive is an even-numbered nozzle, and switching control between first-shot and second-shot can be realized. Then, by applying the clock signal to the clock terminal CK, the even-numbered / odd-numbered driving is switched. The flag signal is switched and output for each column by the MPU 11 in FIG.

In the present embodiment, the switching control is performed for each column. However, the switching control is performed for each column, even for a plurality of columns, or even for each row if possible as a product positioning. There may be. A circuit for automatically switching and outputting the flag signal for each column is provided in the gate array 1.
4.

As described above, by realizing the drive control means that alternately repeats the adverse effects of the shift driving and the effect of repairing the adverse effects, it is possible to suppress the image defect, which is the adverse effect of the shift driving, and obtain the effect of speeding up refilling. It is possible to perform high-speed and high-quality image recording.

(Embodiment 2) Next, a description will be given of an embodiment 2 for controlling the relationship of the first hit and the second hit during the shift driving.

In the above-described embodiment, the order of the first hit and the second hit is switched by the gate array 14 for each column. It seems that the occurrence frequency is low, but the printing ratio is very different for each column, for example, one vertical dot line
In the case where printing is performed at dot intervals, it is assumed that the control method of the above-described embodiment hardly produces the effect of switching and controlling the relationship between first-shot and second-shot. That is, the actual recording is made only at the timing of the first hit. The same problem is likely to occur regardless of the method of automatically switching every two columns or the method of automatically switching every three columns. The control is performed so that the switching effect can be obtained.

That is, the relationship of the first hit and the second hit can be designated.
A / 0 register (hereinafter referred to as a flag) is arranged in the GA 104 in FIG. 11 and 1/0 information is set in the flag by the MPU 11 as necessary, so that
This is for controlling the relationship of the last shot. In this embodiment, M
The shift drive is controlled so that when the PU set value to the above flag is 0, odd-numbered nozzle pre-firing is performed, and when the set value is 1, even-number nozzle pre-firing.

The MPU 11 counts the number of first-shot and second-shot dots of odd-numbered nozzles and even-numbered nozzles, and monitors the switching timing by the flag. In the present embodiment, the average number of dots of the post-discharge nozzle is 10
Switching is made between first-stroke and second-stroke based on the fact that the value exceeds 00 dots. That is, since the recording head of this embodiment has a 64-nozzle configuration as described above, the total number of dots is 640.
When the number of dots exceeds 00 dots, first-after-first-shot is switched.

Next, the operation when printing is performed using the printing apparatus having the above-described configuration will be described with reference to the flowchart of FIG.

When the power of the printing apparatus is turned on in step S100, the counter of the number of dots to be first-shot is reset / set (S110). Thereafter, the process waits until a print signal is input (S120), and after receiving the print signal, printing of one column is performed first (S130). Next, in step S140, the number of first-shot dots in the one column is incremented (updated) in the counter, and the updated value is equal to the first-shot number.
If the later-running switching level has been exceeded (S15
0), that is, as described above, in the present embodiment, when the counter of the number of first-shot dots exceeds 64000 dots, the value of the first-shot / last-shot switching flag of the gate array 14 is switched, and the value of the counter is changed. Is reset / set (S160), and the process returns to the standby state for the print command. Hereinafter, the control is similarly repeated.

In the present embodiment, the determination of the switching of the pre-firing and post-firing is made based on the total number of dots of the pre-firing nozzle.
A method in which the number of dots is counted for each nozzle and switching is performed with the maximum number of print dots may be employed. The purpose of this embodiment is that the switching timing is unconditionally performed in the above-described embodiment, whereas in this embodiment, the number of printing dots is counted as a substitute characteristic, and the switching timing is determined according to the count value. It is in the point. Therefore, the present invention is not limited by the number of dots for switching. Furthermore,
Instead of counting the number of dots, the printing time or the transition of the recording head temperature may be used as a judgment material.

The structure and operation other than the switching timing detecting means for judging the switching between the first hit and the second hit at the time of the shift driving are the same as those of the above-described embodiment, and the description thereof will be omitted.

(Embodiment 3) Next, a description will be given of an embodiment 3 for restoring the adverse effect given to the first-shot nozzle by the shift driving.

In the second embodiment, the harmful effect is repaired by appropriately switching between first-stroke and last-stroke during printing.
A system that performs a repair operation by heat other than printing may be used.

As is well known, in an on-demand type ink jet recording apparatus that performs recording by driving a necessary heater when necessary, a position other than a printing unit is used for the purpose of preventing a discharge failure of a non-recording nozzle. Discharges all nozzles (hereinafter, referred to as preliminary discharge) on a regular basis.

In this embodiment, at the time of the preliminary ejection, a repair operation of the first-shot nozzle at the time of printing is performed. That is, during the preliminary ejection, the preliminary ejection drive control is performed so that the order of the first ejection and the second ejection is opposite to that of the printing, and the above-described restoration is performed.

Specifically, at the time of printing, as in the above-described conventional example,
Odd nozzles are hit first, and even nozzles are hit first during the preliminary ejection. Further, in the preliminary ejection, the ejection heat is performed 100 times / times / number of nozzles at a timing of once every 12 seconds during printing.

By performing the printing heat and the preliminary discharge heat as described above, it becomes possible to simultaneously realize the refreshing of the unused nozzle and the recovery from the adverse effect of the shift drive each time the preliminary discharge is performed.

In the first and second embodiments, since the drive order is switched during the printing heat, the gate array set value is changed for the switching (the flag is rewritten).
However, in this embodiment, the switching is not performed at the time of printing.
MPU1 at the time of printing where U11 performs the processing most frequently
One load can be reduced.

In the present embodiment, the above-mentioned restoration means is established by reversing the order of the first-shot and the second-shot at the time of the preliminary ejection. Alternatively, a method of switching between first-stroke and second-strike may be used. Also, count the number of first-shot dots,
A method of controlling the number of first-shot and second-shot firings at the time of preliminary ejection according to the count value may be employed.

Further, since the interval and the number of shots for performing the preliminary ejection are originally performed for the purpose of preventing the ejection failure of the nozzle exposed for a long time without performing printing, the condition setting of the interval and the number of shots is performed. Is determined by the discharge reliability,
When the restoration function is also used as in this embodiment, a condition that satisfies the restoration function may be set.

The other constructions and operations other than the harmful repair means of the first-shot nozzle are the same as those of the above-described embodiment, and the description thereof will be omitted.

In each of the above embodiments, the drive timing is shifted every other nozzle. However, the drive timing may be shifted every two or more nozzles. Just change the order.

The present invention brings about an excellent effect particularly in a recording head and a recording apparatus which use thermal energy among ink jet recording methods.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method 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, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, to the electrothermal transducer arranged corresponding to the sheet or liquid path in which is held, This is effective because heat energy is generated in the electrothermal transducer, and the film is boiled on the heat-acting surface of the recording head. As a result, bubbles in the liquid (ink) can be formed in one-to-one correspondence with the drive signal. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. Examples of the drive signal in the form of a pulse include those described in U.S. Pat.
Suitable are those described in US Pat. No. 45,262. If the conditions described in U.S. Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,558,333 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 459600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication (Kokai) No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing pressure waves of thermal energy. The present invention is also effective as a configuration based on JP-A-59-138461 which discloses a configuration corresponding to a discharge unit.

In addition, the form of the ink jet recording apparatus of the present invention is not only one used as an image output terminal of an information processing apparatus such as a computer, but also a copying apparatus combined with a reader or the like, and further a facsimile apparatus having a transmission / reception function. And the like.

[0087]

According to the present invention, the alternate hitting control means for appropriately controlling the relationship between the first hitting and the second hitting during the shift driving is provided. Prevents discharge failure of a certain pre-shot nozzle and achieves the effect of shortening the maximum refill retreat amount and increasing the refill speed, which are the effects of alternate printing, while preventing discharge failure of the pre-print nozzle and achieving high-speed printing. And high image quality can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a main body of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is an exploded perspective view showing the ink jet cartridge.

FIG. 3 is a diagram for explaining a heater board.

FIG. 4 is a block diagram illustrating a control circuit according to the embodiment.

FIG. 5 is a block diagram showing a control configuration shown in FIG. 4;

FIG. 6 is a diagram for explaining a conventional recording head driving method.

FIG. 7 is a diagram for explaining a conventional recording head driving method.

FIG. 8 is a diagram showing a difference between a maximum meniscus retreat amount and a refill time due to a refill speed difference when a first nozzle receives and does not receive a discharge reaction pressure wave after discharge.

FIG. 9 is an explanatory diagram for explaining odd-numbered nozzle pre-driving drive according to the embodiment of the present invention.

FIG. 10 is an explanatory diagram for explaining an even-numbered nozzle pre-driving drive according to the embodiment of the present invention.

FIG. 11 is a block diagram showing details of a control configuration shown in FIG. 5;

FIG. 12 is a flowchart showing the operation of the embodiment of the present invention.

[Explanation of symbols]

 8c Discharge heater 11 MPU 12 ROM 13 RAM 14 Gate array 18 Recording head

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Atsushi Arai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tsutomu Iwasaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Daigoro Kanematsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (56) References JP-A-64-5161 (JP, A) JP-A-3-227637 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B41J 2/01 B41J 2/05 B41J 2/175

Claims (6)

(57) [Claims] A plurality of ejection portions for ejecting ink [1 claim], a recording head having a plurality of common liquid chamber for supplying ink to the ejection portion of, among the plurality of ejection of the recording head, the adjacent ejection portions and a driving unit for non-simultaneously ejecting ink from one of the adjacent ejection units where the non-simultaneous ejection operation is performed.
The discharge from the discharge section where the discharge is performed first
To the other end of the adjacent discharge section
The discharge from the discharge section where the discharge is performed
An ink jet recording apparatus characterized by comprising a drive control means for changing. 2. An ink jet recording apparatus according to claim 1, wherein said driving means performs alternate ejection driving for alternately ejecting ink from adjacent ejection units among a plurality of ejection units of the recording head. 3. The method according to claim 2, wherein the driving control unit controls the driving of the adjacent discharge port.
Average of the count value that counted the number of discharges from one side of the unit
Switch the order of ejection drive when the value exceeds the specified value
An ink jet recording apparatus according to claim 1, wherein the that. 4. An ink jet recording apparatus according to claim 1, wherein said drive control means switches the order of ejection drive at the time of preliminary ejection without recording. 5. The apparatus according to claim 1, wherein the drive control unit is configured to perform the preceding operation every time the ejection drive to all the ejection units of the recording head is completed.
2. The ink jet recording apparatus according to claim 1 , wherein the order of ejection and subsequent ejection is switched . 6. The ink jet recording apparatus according to claim 1, wherein the recording head causes a state change in the ink by heat, and discharges the ink based on the state change.