JPH10146977A - Drive device of ink jet printing head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the printing density irregularity of a unit head boundary inconspicous by controlling the emitting block of a printing head so as to minimize the emitting time difference of emitting blocks adjacent to each other between unit heads. SOLUTION: A printing head is constituted of a plurality of unit heads and each of the unit heads is divided into eight blocks (e.g; blocks 1B-1-1B-8) and, when these blocks are heated in the order of 1B-1, 1B-8, 1B-2, 1B-7..., a temp. rise of (TMP-b)-(TMP-a) is generated from the emission of the block 1B-1 to that of the block 1B-8 and this temp. rise is about 1 deg.C. That is, it is shown that the temp. difference of emitted ink can be suppressed to about 1 deg.C between the emission of the block 1B-1 and that of the block 1B-8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head driving apparatus in an ink jet printing apparatus, and more particularly to a print head control for performing print head ejection control in a divided manner.

[0002]

2. Description of the Related Art An ink jet system, in particular, a bubble jet system in which ink is ejected by the pressure of bubbles generated by using thermal energy, is a system widely used as a printing apparatus in printers, copiers, facsimile machines, and the like. . Further, recently, since it has advantages such as the necessity of an original plate, it is being used in an electronic textile printing apparatus for printing on a cloth.

In these types of printing apparatuses,
There is a demand for an improvement in printing speed, and as one of the methods, a long head has been proposed and used.

Head Configuration An example of the configuration of the main part of the long head will be described with reference to FIG. The example shown in FIG.
i (ejection port pitch 70.5 μm), number of ejection ports 1408
(Print width 99.3 mm).

In FIG. 12, eleven unit substrates (hereinafter referred to as heater boards) 1 to 11 (3 to 7 are not shown) have elements 1A to 11A for generating energy used for ejection.
(3A to 7A not shown) is 128 at a density of 360 dpi.
Are provided. Here, electrothermal conversion elements (hereinafter, heaters) for applying heat to the ink are used as the elements 1A to 11A. Further, the heater boards 1 to 11 are provided with a signal pad (not shown) for enabling supply of an external electric signal at an arbitrary timing, and a power pad (not shown) for supplying electric power and the like. ing.

[0006] The heater boards 1 to 11 configured as described above.
Are bonded and fixed to a portion along a side in the longitudinal direction of a support (hereinafter, base plate) 300 formed of a material such as metal or ceramics. Also, the control circuit board 4 similarly adhered and fixed to the base plate 300
A drive circuit (60 in FIG. 15) for selectively driving each of the heaters 1A to 11A according to the print data
0) is formed. Further, the base plate 300
The top plate 200 is joined to the heater boards 1 to 11 so as to overlap the heater boards 1 to 11. The top plate 200 is formed with a groove and a discharge port (hereinafter, nozzle) array 201 for forming an ink path for each of the heaters 1A to 11A, and communicates with each ink path in common. A common liquid chamber groove (hereinafter, liquid chamber) for supplying ink to these is formed.

As described above, a heater board having a plurality of heaters provided on one surface side of a base plate,
An ink jet can be obtained by attaching a long top plate (grooved member) that covers the heaters of the plurality of heater boards to the plurality of arrayed substrates.

Heater Board FIG. 13 shows the structure of the heater 1A of the heater board 1 as a representative of the heater boards 1 to 11. The heaters 2A to 11A of the heater boards 2 to 11 have the same configuration as that shown in FIG.

The 128 discharge heaters 1 in the heater board
A is 1A-1 on the end face of the heater board as shown in FIG.
~ 1A-128. With this heater, 128 ink jets can be obtained from one heater board through a nozzle row. A signal line (not shown) from a drive circuit (600 in FIG. 15) is connected to each of the 128 heaters, and is heated by block heat control of the drive circuit. Here, the block heat control is a discharge control method performed for distributing electric power for driving a heater and reducing interference due to discharge of adjacent nozzles. The heat block is divided into eight by 16 nozzles (1B-1 to 1B-8), and each block is further divided into two by odd-numbered nozzles (a) and even-numbered nozzles (b).

[0010] The divided nozzles are discharged in time series as shown in FIG. FIG. 14 schematically shows the ink jets ejected from the heater board 1 with the horizontal axis representing the time axis. The inkjet ejected from the nozzle of the heater 1A-1 is represented as 1A-1d, and the inkjet ejected from the nozzle of the heater 1A-2 is represented as 1A-2d, and "a row of the 1B-1 block (odd number nozzle)" →
“B row of 1B-1 block (even nozzle)” → “1B
-A column of -2 block "→" b column of 1B-2 block "->
... → “a row of 1B-8 blocks” → “b row of 1B-8 blocks”.

As described above, by performing block-divided time-sequential discharge, the power required for discharge is dispersed, and interference between adjacent nozzles is reduced by divided-discharge of even-numbered nozzles and odd-numbered nozzles to achieve high quality. Image formation is realized.

[0012] The block diagram of the block heating control block heat control circuit 600 shown in FIG. 15. The block heat control circuit 600 is located on the control circuit board 400 and controls the heater boards 1 to 11.
In the figure, reference numeral 601 denotes a pattern generator which generates a predetermined block heat signal in response to a clock CLK from a printer control circuit (not shown) and a print trigger signal ST-SP. Control is performed so that a block heat signal is output when the trigger signal ST-SP is at the [H] level. From the pattern generator 601, the block heat control signal 6
02, 603, 604, 605 and 606 are outputted, and these signals are outputted to the heater boards 1 to 11 in parallel, respectively.

FIG. 16 is a logic table of the block heat signal. Reference numerals 602 and 603 denote signals for selecting odd nozzles and even nozzles. Odd nozzles are provided under the condition of 602 = [1] and 603 = [0], and even nozzles are provided under the condition of 602 = [0] and 603 = [1]. Is selected. Together with these two signals, 60
Three signals of 4,605,606 are output, and these are used to select an eight-division block. 604 = [0], 605 =
[0], 606 = First block (B-
1) is selected. The selection conditions for each block are shown in FIG.
As shown in FIG.

FIG. 17 is a diagram schematically showing an output pattern of a general block heat signal and an ink jet state at that time. Here, ejection control is performed from block 1 to block 8 in the order of odd number → even number with time. In this state, distribution of heat power and prevention of interference between adjacent nozzles, which are the objects of block control, are realized.

[0015]

With the structure described above, even a long head having a large number of nozzles can realize a stable ink jet with a small driving power by means of ejection control.

However, even in the ink jet head having the above-described structure, there is a problem of printing quality stability due to a time lag of a printing block due to block heat control.

FIG. 18 is a diagram showing a change in the ink temperature of the liquid chamber in the ink jet by the block control of FIG. Block 1B-
During the period between the first discharge and the discharge between the blocks 1B-8, the temperature of the liquid chamber, in which the heat generated by the discharge heater is deposited on the ink in the liquid chamber, rises. As the eight blocks (1B-1 to 1B-8) in the upper diagram of FIG. 18 are sequentially heated,
As shown in the lower diagram of FIG. 18, the temperature of the liquid chamber increases. In this figure, the horizontal axis shows the time required for block heat discharge,
The vertical axis shows the temperature rise of the ink near the nozzles when ink jet is performed from all 128 nozzles of the heater board 1. As is apparent from the figure, (TMP-TMP) is required between the ejection of block 1B-1 and the ejection of block 1B-8.
b) The temperature rise of-(TMP-a) occurs and this temperature rise reaches about 8 ° C. In other words, it indicates that there is a temperature difference of about 8 ° C. between the ejection ink in the ejection of the block 1B-1 and the ejection of the block 1B-8.

FIGS. 19 and 20 illustrate the effect of the temperature increase on the ink jet.

FIG. 19 shows the temperature of ink near the nozzle on the horizontal axis and the amount of ink-jet ink droplets ejected from the nozzle on the vertical axis. In the ink jettable area, when the temperature of ink at the time of ejection rises, the amount of ejected ink drops changes. The correlation between the ejection amount and the temperature has a proportional relationship as shown in FIG. Where Δt
A change in the discharge amount of Δd is caused with respect to the change in temperature. In the ink jet print head of this embodiment, 1
A change in the ink temperature of ° C. results in a difference in the ejection amount of about 2 pl. The average amount of ink ejected at about 40 ° C. is 5
0 pl, so 4%
A variation in the amount of ejected ink occurs to the extent.

FIG. 20 shows the influence on the actual printing due to the fluctuation of the discharge ink amount. The left diagram in FIG. 20 shows the same thing as the upper diagram in FIG. 18 (schematic diagram of the discharge of the heater board) continuously from heater boards 1 to 11, and the right diagram shows the discharge amount of the ink droplets 1408. The horizontal axis indicates the ink ejection amount, and the vertical direction indicates the nozzle row direction. The discharge amount increases as going to the right in the figure and decreases as going to the left. In the figure, the amount of ink droplets ejected from the heater block 1B-1 is 1B-1b.
Indicated by. Similarly, the heat blocks 1B-8, 2B-1,... Discharge the ink droplet amounts 1B-8b, 2b-1b,.

In FIG. 20, the ink droplet amounts 1B-1b and 1
For B-8b, as described above, about 3
1B-8b has a larger ink amount than 0% 1B-1b. Since the heater boards 1 to 11 are driven in a similar manner in parallel, the ejection conditions are almost the same. Therefore, there is a large difference in the amount of ink discharged between adjacent heater boards.

For example, the eighth block 1 of the heater board 1
B-8 and a boundary 1C between ink droplets 1B-8b and 2B-1b output from the first block 2B-1 of the heater board 2.
In this case, an ink jet with a different ink droplet amount of about 30% is performed. This difference in ink droplet volume of about 30% causes unevenness in printing depending on the printing medium. In particular, when printing is performed on a print medium having low perpendicular absorption, the unevenness tends to be remarkable. This print unevenness similarly occurs between adjacent heater boards 1C, 2C,..., 9C, and 10C.

Here, the uneven printing 1D, 2, 3,..., 7D between the blocks in the heater board has a small density difference.
This is not a level that causes printing problems.

As described above, in the conventional heat block control, printing unevenness between heater boards in a print head has been a problem.

It is an object of the present invention to provide an ink jet print head driving apparatus which has solved the above-mentioned problems.

[0026]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of discharge ports are arranged in series, and each of the discharge ports is independently controlled by energy from a discharge energy generating element. When a plurality of unit heads for ejecting ink from the ejection ports are arranged in the ejection port arrangement direction, and when the ink ejection is performed by temporally shifting each of the ejection blocks obtained by dividing the inside of the unit head into a plurality of ejection blocks. And a discharge control means for controlling the discharge energy generating element so as to minimize a difference in ink discharge timing between two adjacent discharge blocks between adjacent unit heads.

According to a second aspect of the present invention, in the first aspect, the ejection control means alternately ejects ink from each of the ejection blocks at both ends in the ejection port arrangement direction in the unit head toward the center. It is characterized by.

According to a third aspect of the present invention, in the first aspect, the discharge control means sequentially performs ink discharge from one end of the discharge block along the direction of arrangement of the discharge ports in the unit head, and Are characterized in that the ejection order directions are mutually opposite ejection port arrangement directions between adjacent unit heads.

Further, according to a fourth aspect of the present invention, in the third aspect, the discharge control means changes the direction of the ink discharge order in the unit head according to the scan switching of the print head. .

Further, according to a fifth aspect of the present invention, in the second aspect, the discharge control means includes a pattern generator for supplying discharge order information of each discharge head in the unit head.

According to a sixth aspect of the present invention, in the third aspect, the discharge control means includes a pattern generator for supplying a single discharge order information for each discharge head in the unit head, and a pattern generator for every other pattern generator. And an inverter for inverting and supplying the ejection order information from the pattern generator to the unit head.

According to a seventh aspect of the present invention, in the fourth aspect, the discharge control means includes a pattern generator for supplying a single discharge order information for each discharge head in the unit head, and a pattern generator for every other one. A first inverter for inverting and supplying the ejection order information from the pattern generator to the unit head, and inverting the single ejection order information at the output end of the pattern generator in response to the scan switching every other time And a second inverter that performs the operation.

Further, the invention of claim 8 is based on claims 1 to 7
In any one of the above, the ejection control means alternately performs ink ejection from odd-numbered ejection ports and ink ejection from even-numbered ejection ports in the ejection block.

Further, the invention of claim 9 is the invention of claims 1 to 8
In any one of the above, the discharge energy generation element is an electrothermal conversion element.

Further, the invention of claim 10 is the invention of claims 1 to
9, wherein the number of the unit heads is an odd number.

[0036]

DETAILED DESCRIPTION OF THE INVENTION A block diagram of a block control circuit 700 of the block control unit according to the present invention in a first embodiment Figure 1. Block control circuit 70
0 is on the control circuit board 400 and the heater boards 1 to 1
1 is controlled. In the figure, reference numeral 601 denotes a clock CLK and a print trigger signal ST from a printer control circuit (not shown).
A pattern generator that generates a predetermined block heat signal by using -SP. Control is performed such that a block heat signal is output when the trigger signal ST-SP is at the [H] level. The block heat control signals 602, 603, 604, 60
5, 606 are output in parallel with heater boards 1 to 11, and 604 to 606 are output in parallel with heater boards 1, 3, 5, 7, 9, 11 and signal inverting circuits 701, 702, 703, respectively. , 704, 705. The signal inverting circuits 701 to 705 respond to a control signal 706 from a printer control circuit (not shown) to invert or invert the block heat control signals 604 to 606 input to the signal inverting circuits 701 to 705. The block heat control signals (701a to 705c) are output to the heater boards 2, 4, 6, 8, and 10. The signal inverting circuits 701 to 705 are controlled so as to output normal rotation when the control signal 706 is “1” and to output inverted when the control signal 706 is “0”.

FIG. 2 shows an output pattern of the block heat signals 602 to 606 in FIG. 1 and a schematic diagram of the ink jet state at that time, using the heater board 1 as an example. The logic of the block heat signal is the same as in FIG.

By the block heat control shown in FIG. 2, the arrangement of the eight heat blocks in the heater board becomes an inverted "-" shape, and the printing interval between adjacent blocks falls within one or two blocks. In particular, the blocks at both ends of 1B-1 and 1B-8 have a printing interval of one block.

FIG. 3 is a diagram showing a change in the ink temperature of the liquid chamber in the ink jet by the block control of FIG.
In the time-series ejection by the block control, the heat generated by the ejection heater is accumulated in the ink in the liquid chamber between the ejection of the block 1B-1 and the ejection between the blocks 1B-5, and the temperature of the liquid chamber rises. As the eight blocks in the upper diagram of FIG. 3 are heated in the order shown in FIG. 2, the temperature of the liquid chamber increases as shown in the lower diagram of FIG. In this figure, the horizontal axis indicates the time required for block heat ejection, and the vertical axis indicates the temperature rise of the ink near the nozzles when ink jetting is performed from all 128 nozzles of the heater board 1. As is clear from the figure, the ejection of the block 1B-1 starts with the ejection of the block 1B-
By the discharge of No. 8, a temperature rise of (TMP-b)-(TMP-a) occurs, and this temperature rise is about 1 ° C. That is, it is shown that the temperature difference between the ejected inks can be suppressed to about 1 ° C. between the ejection of the block 1B-1 and the ejection of the block 1B-8. Also, at most block 1B-
1 to the discharge of block 1B-2, (TMP
-C) The temperature rise of (TMP-a) can be suppressed to about 2 ° C.

FIG. 4 shows the effect of this temperature rise on the ink jet. Here, the relationship between the temperature of the ink near the nozzle and the amount of the ink droplet of the ink jet ejected from the nozzle is as described with reference to FIG.

The left diagram in FIG. 4 is the same as the upper diagram in FIG. 3 (schematic diagram of the ejection of the heater board), and shows continuously the heater boards 1 to 11, and the right diagram is the ejection of the ink droplets. The amount is expressed over a 1408 nozzle print head. The horizontal axis is the ink ejection amount, and the vertical direction is the nozzle row direction. The discharge amount increases as going to the right in the figure and decreases as going to the left. In the figure, the amount of ink droplets ejected from the heat block 1B-1 is indicated by 1B-1b. Similarly, 1B-
Each heat block of 8, 2B-1, ... is 1B-8b,
2b-1b,... Are ejected.

In FIG. 4, the ink droplet amounts 1B-1b and 1B
In -8b, the difference in ink temperature is about 1 ° C. as described above,
Although the amount of ink is slightly larger in 1B-8b than in 1B-1b, the amount of change can be minimized. Since the heater boards 1 to 11 are driven in a similar manner in parallel, the ejection conditions are almost the same. Therefore, the difference in the amount of ejected ink between the adjacent heater boards can be minimized.

For example, the eighth block 1 of the heater board 1
B-8 and a boundary 1C between ink droplets 1B-8b and 2B-1b output from the first block 2B-1 of the heater board 2.
In this case, ink jet is performed with the minimum change in the amount of ink droplets. Therefore, it is possible to minimize the occurrence of unevenness in the printing state of the printing medium. This printing state is between the adjacent heater boards 1C, 2C,.
This can be similarly realized with 10C.

Here, the printing unevenness 1D, 2, 3,..., 7D between blocks in the heater board is a density difference of up to two blocks, but the change amount is small and not a level that causes a printing problem. .

Second Embodiment In the block diagram of the block control circuit 700 of the block control means according to the present invention shown in FIG.
The control signals 706 of 01 to 705 are always “0”.
FIG. 5 shows an output pattern of the block heat signals 602 to 606 when the heater board 1 is fixed to FIG. Here, the logic of the block heat signal is the same as in FIG.

By always fixing the control signal 706 to "0", the heater boards 1, 3, 5, 7, 9, 1
1 is the order of the heat blocks 1 to 8 (for example, the order of 1B-1 to 1B-8 in the heater board 1), and the heater boards 2, 4, 6, 8, and 10 are the order of the heat blocks 8 to 1 ( For example, in heater board 2, 2B-8 to 2B-8
Heat control is performed in the order of (B-1). As a result, as shown in FIG. 5, the block heat control of the different heater boards causes the arrangement of the 16 heat blocks of the adjacent heater boards to be in the shape of a “ku” or the shape of an inverted “ku”. The printing interval between blocks (for example, 1B-8 and 2B-1) is "0", and the difference in ejection temperature is close to zero. Further, adjacent heat blocks (for example, 1B-1 and 1B-2) in the heater block have one printing interval.

FIG. 6 is a diagram showing a change in the ink temperature of the liquid chamber in the ink jet by the block control of FIG.
In the time-series discharge by the block control, heat generated by the discharge heater is generated in the liquid chamber between the discharge of the block 1B-1 and the discharge of the block 2B-8 and the discharge of the block 2B-8 to the block 2B-1. And the temperature of the liquid chamber rises. The 16 blocks in the upper diagram of FIG.
As the heating is performed in the order shown in FIG. 6, the temperature of the liquid chamber rises as shown in the lower diagram of FIG. In this figure, the horizontal axis indicates the time required for block heat ejection, and the vertical axis indicates the temperature rise of the ink near the nozzles when ink jetting is performed from all 256 nozzles of the heater boards 1 and 2. As is clear from the figure, (TMP-b)-(TMP-b) is required between the ejection of block 1B-8 and the ejection of block 2B-1.
The temperature change of a) occurs, and this temperature change is almost zero. That is, the ejection of block 1B-8 and the ejection of block 2
The ejection of B-1 indicates that there is almost no temperature difference between the ejected inks. Further, at the maximum, between the ejection of the block 2B-2 and the ejection of the block 2B-1, (TMP-
c) The temperature rise of-(TMP-b) can be suppressed to about 1 ° C.

FIG. 7 shows the effect of the temperature increase on the ink jet. Here, the relationship between the temperature of the ink near the nozzle and the amount of the ink droplet of the ink jet ejected from the nozzle is as described with reference to FIG.

The left diagram in FIG. 7 is the same as the upper diagram in FIG. 6 (schematic diagram of the discharge of the heater board), and shows continuously the heater boards 1 to 11, and the right diagram is the discharge of the ink droplets. The amount is expressed over a 1408 nozzle print head. The horizontal axis is the ink ejection amount, and the vertical direction is the nozzle row direction. The discharge amount increases as going to the right in the figure and decreases as going to the left. In the figure, the amount of ink droplets ejected from the heat block 1B-1 is indicated by 1B-1b. Similarly, 1B-
Each heat block of 8, 2B-1, ... is 1B-8b,
2b-1b,... Are ejected.

In FIG. 7, the ink droplet amounts 1B-1b and 1B
As described above, in the adjacent block in the -2b heater board, the difference in ink temperature is about 1 ° C., and 1B-
Although the amount of ink is slightly larger in 2b, the amount of change can be minimized.

The heater boards 1, 3, 5, 7, 9, 11 and the heater boards 2, 4, 6, 8, 10 are driven in parallel, so that the inks of 1B-8b and 2B-1b As described above, there is almost no difference in the ink temperature between the droplet amounts, and the difference in the ink amount between 1B-8b and 2B-1b can be minimized.

For example, the eighth block 1 of the heater board 1
B-8 and a boundary 1C between ink droplets 1B-8b and 2B-1b output from the first block 2B-1 of the heater board 2.
In this case, ink jet is performed with the minimum amount of ink droplets. Therefore, it is possible to minimize the occurrence of unevenness in the printing state of the printing medium. This printing state is determined between the adjacent heater boards 1C, 2C,.
This can be realized similarly at 0C.

Here, the printing unevenness 1D, 2, 3,..., 7D between blocks in the heater board has a density difference of one block at the maximum, but the change amount is small and is not at a level that causes a printing problem. .

Third Embodiment FIG. 8 is a block diagram of a block control circuit 800 of the block control means according to the present invention. 601 and 701 in the figure
Reference numeral 705 (partially not shown) is the same as in the first and second embodiments. The block heat control signal output from the pattern generator 601 passes through the signal inverting circuit 801 to each of the heater boards 1 to 11 (a part of the signal passes through the inverting circuits 701 to 705. This part is the second embodiment). Same as the form.) Output. The signal inversion circuit 801
Control signal 8 from printer control circuit (not shown)
02, the block heat control signal from the pattern generator 601 is output in the normal or inverted state. The signal inverting circuit 801 is controlled so as to output a normal output when the control signal 802 is “0” and to output an inverted output when the control signal 802 is “1”.

In the present embodiment, as shown in FIG. 9, the control signal 802 of the signal inverting circuit 801 is set to "0" at the time of forward scan and "1" at the time of backward scan of the printing apparatus of the reciprocating serial scan printing system. Is controlled. The reciprocating serial scan printing method is a serial scanning printing apparatus that forms a two-dimensional image while moving a print medium such as paper in the Y direction by moving the ink jet print head in the X direction. It refers to one that forms an image while moving in both positive and negative directions.

FIG. 11 shows output patterns of the block heat signals 805 to 807 in FIG.
2 shows the control state of the heater board 1 as an example. The logic of the block heat signal is the same as in FIG. As can be seen from FIG. 11, at the time of switching (t2) between the first scan (forward path) and the second scan (return path), the control signal 802 of the signal inversion circuit 801 switches, and the block heat control signals 805 to 807 are inverted. ing. The block heat control in one-way scanning is the same as the control method of the second embodiment.

By the block heat control shown in FIG. 11, the arrangement of the 16 heat blocks in the heater board becomes a "-" shape or an inverted "-" shape, and the printing interval between adjacent blocks is minimized. , As described in the second embodiment.

The left diagram of FIG. 10 schematically shows a continuous discharge state from the heater boards 1 to 11, wherein the upper portion is for the first scan and the lower portion is for the second scan. The right diagram of FIG. 10 shows the discharge amount of ink droplets over a print head of 1408 nozzles. The horizontal axis indicates the ink discharge amount, and the vertical direction indicates the nozzle row direction. The discharge amount increases as going to the right in the figure and decreases as going to the left. In the figure, 11B-8b discharged from the block 11B-8 at the time of the first scan and the second
1B-1 ejected from block 1B-1 during scanning
At the boundary with b, the change in the ejection condition is small (504), and the unevenness of the print density at the boundary (501) between the first scan and the second scan is not noticeable.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

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 is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. 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 a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US 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.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, 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 on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, the recording head fixed to the apparatus main body or the electric connection with the apparatus main body or the ink from the apparatus main body is attached to the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

Further, it is preferable to add ejection recovery means for the recording head, 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. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of recording heads to be mounted are, for example, not only one provided for single color ink, but also a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not limited to those used as image output terminals of information processing equipment such as computers, copying apparatuses combined with readers and the like, and facsimile apparatuses having a transmission / reception function. It may take a form.

[0068]

As is clear from the above description, according to the present invention, the ejection block control of the print head is controlled so as to minimize the ejection time difference between adjacent ejection blocks between the unit heads. It is possible to make the print density unevenness at the unit head boundary inconspicuous.

[Brief description of the drawings]

FIG. 1 is a block diagram of a heat block control unit according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a block heat control signal and an ink jet.

FIG. 3 is a diagram illustrating a change in ink temperature in heat block control.

FIG. 4 is a diagram illustrating a change in the ejection ink amount.

FIG. 5 is a schematic diagram of a block heat control signal and an inkjet according to another embodiment of the present invention.

FIG. 6 is a diagram illustrating a change in ink temperature in heat block control.

FIG. 7 is a diagram illustrating a change in the amount of ejected ink.

FIG. 8 is a block diagram of a heat block control unit according to still another embodiment of the present invention.

FIG. 9 is a diagram schematically illustrating a print state of reciprocal serial scan.

FIG. 10 is a diagram illustrating a change in a discharge ink amount.

FIG. 11 is a diagram of a block heat control signal during reciprocal serial scanning.

FIG. 12 is an exploded perspective view of a long print head.

FIG. 13 is an internal explanatory diagram of the heater board.

FIG. 14 is a diagram schematically showing a state of ink jet from a heater board.

FIG. 15 is a block diagram of a heat block control unit according to the technology;

FIG. 16 is a diagram showing a logic table of a heat block control signal.

FIG. 17 is a schematic diagram of a block heat control signal and an ink jet according to the related art.

FIG. 18 is a diagram illustrating a change in ink temperature in heat block control according to the related art.

FIG. 19 is a diagram showing a relationship between ink temperature and ink ejection amount.

FIG. 20 is a diagram illustrating a change in the amount of ejected ink in the related art.

[Explanation of symbols]

1-11 Heater board 1B-1-8 Ink jet from heater board 1 1B-1b-8b Amount of ink ejected from heater board 1 2B-1-8 Ink jet from heater board 2 2B-1b-8b Heater board 2 600, 700, 800 Block heat control unit 601 Block heat control signal creation unit 701-705 Logical inversion control unit 801 Logical inversion control unit

Claims (10)

[Claims] 1. A unit head in which a plurality of ejection ports are arranged in series, and a unit head that ejects ink from each ejection port with energy from an ejection energy generating element that is independently controlled is arranged in the ejection port arrangement direction. A plurality of print heads, and ink ejection timing of two adjacent ejection blocks between adjacent unit heads when performing ink ejection with a time shift for each ejection block obtained by dividing the inside of the unit head into a plurality. An ink jet print head driving device, comprising: an ejection control means for controlling the ejection energy generating element so as to minimize the difference. 2. The ink jet print head according to claim 1, wherein the discharge control means performs ink discharge alternately toward the center from each of the discharge blocks at both ends in the discharge port arrangement direction in the unit head. Drive. 3. The discharge control unit according to claim 1, wherein the discharge control means sequentially discharges ink from one end of the discharge block along a discharge port arrangement direction in the unit head, and the discharge order of the ink is adjacent. An ink jet print head driving device, wherein the discharge port arrangement directions are opposite to each other between unit heads. 4. The ink jet print head driving device according to claim 3, wherein the discharge control means changes the direction of the ink discharge order in the unit head in accordance with the scan switching of the print head. 5. The ink jet print head driving device according to claim 2, wherein the discharge control means has a pattern generator for supplying discharge order information of each discharge head in the unit head. 6. The discharge control unit according to claim 3, wherein the discharge control unit supplies a single discharge order information for each discharge head in the unit head, and the pattern generator supplies a single discharge order information to every other unit head. An ink-jet printhead driving device, comprising: an inverter that inverts and supplies the ejection order information from a generator. 7. The discharge control unit according to claim 4, wherein the discharge control means supplies a single discharge order information for each discharge head in the unit head, and the pattern generator supplies the pattern control information to every other unit head. A first inverter for inverting and supplying the discharge order information from the generator, and a second inverter for inverting the single discharge order information at the output end of the pattern generator in response to the scan switching every other time. An ink-jet printhead driving device, characterized in that: 8. The ejection control unit according to claim 1, wherein the ejection control unit alternately performs ink ejection from odd-numbered ejection ports and ink ejection from even-numbered ejection ports in the ejection block. An ink-jet printhead driving device, characterized in that: 9. The ink-jet printhead driving device according to claim 1, wherein the ejection energy generating element is an electrothermal conversion element. 10. The ink jet print head driving device according to claim 1, wherein the number of the unit heads is an odd number.