JP3307123B2 - 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 head for performing recording by ejecting ink droplets from nozzles by ink droplet ejecting means provided in a flow path corresponding to the nozzles.

[0002]

2. Description of the Related Art The ink jet recording system is capable of high-speed recording, and has almost no noise generated at the time of recording.
Since it can print on plain paper and does not require a fixing process or the like, attention has been paid to the fact that the apparatus can be downsized.

In the ink jet recording method, an electromechanical transducer (for example, a piezoelectric element) is used as means for ejecting ink from a nozzle, and an ink droplet is ejected by a movement accompanying mechanical deformation by an input signal. There is a so-called thermal ink jet system in which a heater generates heat by applying a voltage pulse using an electro-thermal conversion element (heater), and the ink droplet is ejected by the pressure of a vapor bubble generated on the heater due to the generated heat. .

FIG. 13 shows an example of a thermal ink jet recording head described in JP-A-5-155020. FIG. 13A is a cross-sectional view taken along a direction perpendicular to the axial direction of a channel groove. FIG. 13B is a cross-sectional view of FIG.
FIG. 13C is a plan view taken along the line B, and FIG. 13C is a front view as viewed from the nozzle side. In the figure, 1 is a channel substrate, 2 is a heater substrate, 3 is a channel groove, 4 is an ink reservoir, 5 is a nozzle, 6 is an unetched portion, 7, 7a, 7b, 7c are heaters, 8 is an insulating layer, and 9 is an insulating layer. A thick resin layer, a first concave portion,
11 is a second concave portion, 12 is a partition, 13 is an ink droplet, 14
Denotes a recording medium, 15 denotes an ink supply port, and P denotes a nozzle interval.

A channel groove 3 and an ink reservoir 4 are formed in the channel substrate 1 by anisotropic etching, and an opening of the channel groove 3 serves as a nozzle 5. The heater 7 is provided on the heater substrate 2, and an electrode for supplying a drive signal to the heater 7, a protective film, and the like are formed on the heater 7. Further, an insulating layer 8 and a thick resin layer 9 are formed on the heater substrate 2. These two substrates are joined and cut and separated into individual head chips to form a recording head.

[0006] The ink supplied from the ink supply port 15 to the ink reservoir 4 is guided to the channel groove 3 serving as an ink flow path through the second recess 11, and is provided at the bottom of the first recess 10. 7, the pressure of the bubble generated by the heat generation of the recording medium
4 and printing is performed.

As a means for realizing higher-speed printing using such an ink jet recording head, it is conceivable to increase the frequency of repeatedly ejecting ink droplets from one nozzle. However, since the ink must be refilled (refilled) in the flow path after the ink droplet is ejected and before the next ink droplet is ejected, the repetition frequency cannot be made too high. At present, the frequency upper limit is considered to be 4 to 6 kHz for a head corresponding to a resolution of 300 spi.

In order to improve the upper limit of the repetition frequency, the flow path structure in the head and the driving order have been devised. An example of the driving sequence is a so-called interlace driving method as described in JP-A-61-266253.

FIGS. 14 and 15 are explanatory views of a heater driving method in the recording head, and are shown in FIGS.
(A) is the driving voltage of the heater, FIG. 14 (B), FIG.
FIG. 2B is an explanatory diagram of pixels printed on a recording medium.
In the figure, 5a, 5b, 5c, 5d, 5e are nozzles arranged in order, 7a, 7b, 7c, 7d, 7e are heaters of each nozzle, 16 is a drive pulse, 17a, 17b, 17c, 17
d and 17e are pixels, t is a cycle (second) of a drive pulse, and P is a nozzle interval.

FIG. 14A shows a sequential drive system which is not an interlace drive system. In the sequential driving method, the heaters corresponding to the respective nozzles are driven in the order of arrangement from the end. When the heaters 7a, 7b, 7c, 7d, and 7e corresponding to the nozzles 5a, 5b, 5c, 5d, and 5e are sequentially driven by the drive pulse 16 having the cycle t, as shown in FIG. The pixels 17a, 17b, 17c, 17d, and 17e are printed obliquely. FIG. 14B shows the nozzles 5a,
This shows a case where the recording head having 5b, 5c, 5d and 5e moves upward from below in the drawing, or a case where the recording medium moves downward from above. In this case, the driving direction of the heater is referred to as a main scanning direction, and the relative moving direction of the recording medium and the recording head is referred to as a sub-scanning direction.
Therefore, in this example, the nozzles 5a, 5b, 5c, 5
heaters 7a, 7b, 7c, 7d, 7 corresponding to d, 5e
It can be said that e is sequentially driven by one scan in the main scanning direction.

A printing situation on a recording medium will be described. The heater 7a is driven, and the pixel 17a is printed. After t seconds, the heater 7b is driven and the pixel 17b is printed. However, the pixel 17b is printed with a shift of the moving distance between the recording medium and the recording head in t seconds with respect to the pixel 17a. Printing is performed on the recording medium at a position delayed in the sub-scanning direction by an amount corresponding to t. Hereinafter, the pixels 17c, 17d, 17
e is also sequentially printed at a position delayed by t. Since the nozzles 7a, 7b, 7c, 7d, 7e are arranged at a distance of the nozzle interval P, the printed pixels 17a, 1
7b, 17c, 17d, and 17e are printed at an angle as shown in FIG.

In the sequential driving method, since a nozzle which uses an ink droplet to discharge is adjacent to a nozzle which immediately discharges an ink droplet, it takes time to refill ink (refill), which is not suitable for high-speed printing. It is.

On the other hand, in an interlace drive system in which adjacent heaters are driven as far apart as possible in time,
Since the nozzle that ejected ink immediately before is separated from the nozzle that is going to eject ink droplets, the refill time can be reduced, and the repetition frequency can be reduced compared to the case where the adjacent heater is driven continuously. It is known that it can be increased up to about twice.

FIG. 15A shows a driving order of an example of the interlace driving method. In this example, each nozzle 5a,
Each heater 7a, 7 corresponding to 5b, 5c, 5d, 5e
b, 7c, 7d and 7e are drive pulses 16 having a period t,
It is driven every third. That is, the heaters 7a, 7d,
7b, 7e, 7c. The printing status on the recording medium is, as shown in FIG.
7a, 17b, and 17c are separated from the pixel 17c by 17 times as much as t in the sub-scanning direction, pixels 17c to 17d are separated from the pixel 17c by 3 times as much as t in the sub-scanning direction, and pixels 17d to 17e are separated from the pixel 17d to 17e by t in the sub-scanning direction. The resulting pattern is twice as far apart.

[0015] In the interlace driving method, as described above, the distance from a specific nozzle to another nozzle,
After the heater corresponding to a specific nozzle is driven,
Since the relationship with the time until the heater corresponding to another nozzle is driven is not constant, as shown in FIG. 15B, the dot position in the main scanning direction is shifted on the printing medium, for example, printing. By ink drops from all nozzles of the head,
When printing a straight line in the main scanning direction, there is a problem that the pattern becomes uneven (jagged) and linearity is impaired.

Increasing the number of nozzles in the recording head is another means for achieving high-speed printing. For example, it is conceivable to increase the number of nozzles corresponding to the width of the recording paper. In this case, a method of covering the entire width of the recording paper with one recording head, that is, a method of using an elongated head, and a method of linearly connecting a plurality of recording heads to cover the entire width of the recording paper are as follows. is there.

In the former case using a long head, since a thermal ink jet recording head usually uses Si as its substrate material, for example, an A4 short size (2
10 mm) requires a Si wafer of about 203.2 mm (8 inches) or more, and the number of heads that can be manufactured from one wafer is extremely small. Fabrication costs are extremely high. Further, since the number of nozzles per head increases, it becomes very difficult to manufacture a head in which all nozzles, heaters, wirings, etc. are defect-free.

On the other hand, the latter method of connecting a plurality of recording heads in a straight line makes it possible to relatively easily produce a recording head corresponding to the paper width using a recording head produced by a conventional technique. FIG. 16 shows one example.

FIG. 16A is a view from the nozzle side, and FIG.
FIG. 6B is a diagram viewed from the ink supply port side. In the figure, 3
Is a channel groove, 4 is an ink reservoir, 5 is a nozzle, 15
Denotes an ink supply port, 18 denotes a recording head, and 19 denotes an end nozzle. The recording head 18 has the same structure as the recording head described with reference to FIG. In this case, the interval between the end nozzles 19 of the adjacent recording heads must be arranged at a distance P of one pixel.
8, the distance m from the end nozzle 19 to the head end is shortened, so that processing is difficult and the end nozzle 19
Does not have enough capacity for the ink reservoir 4,
There is a problem that printing defects are likely to occur.

To solve this problem, a so-called staggered connection as shown in FIG. 17 can be considered. FIG. 17A is a view from the nozzle side, and FIG.
FIG. 3 is a diagram viewed from the ink supply port side. In the figure, the same parts as those in FIG. 16 are denoted by the same reference numerals, and description thereof will be omitted. In this arrangement, in the recording head 18, the distance m from the end nozzle 19 to the head end can be sufficiently set, so that the above-described problem of the printing failure of the end nozzle does not occur. However, even in this arrangement, the problem that linearity in the scanning direction is lost when the interlace driving method is adopted has not been solved.

[0021]

[0022]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an ink jet recording apparatus which does not impair the linearity in the main scanning direction when interlaced printing is employed. The purpose is to do so.

[0023]

According to a first aspect of the present invention, there are provided a plurality of nozzles arranged at equal intervals on a straight line, ink flow paths corresponding to the respective nozzles, ink droplet ejecting means, and respective ink flows. An ink jet recording head having a common liquid chamber and an ink supply port for supplying ink to a path, and an ink jet recording apparatus having control means for controlling the driving of the ink droplet ejecting means, wherein the control means is apparently from the top With respect to the nozzles divided by a predetermined number, each section is sequentially selected, and in the selected section, one nozzle sequentially selected from the head side is driven for each selection of the section. In the direction in which the nozzles are arranged, the dot arrangement of printing by the nozzles in the same section is the same as that of the recording paper. And it is characterized in that it is inclined by an angle perpendicular to the direction of relative movement between Kujetto recording head.

According to a second aspect of the present invention, ink is supplied to a plurality of nozzles arranged at equal intervals on a straight line, ink flow paths corresponding to the respective nozzles, ink droplet ejecting means, and respective ink flow paths. An ink jet recording head having a common liquid chamber and an ink supply port for controlling the driving of the ink droplet ejecting means, the control means are apparently divided by a predetermined number from the top. For each nozzle, each section is divided into a first half and a second half, and each section in the first half and the second half is alternately and sequentially selected. In the selected section, each section is selected. The jump drive is performed so that one nozzle sequentially selected from the head side is driven, and the nozzles are arranged in the same direction. It is characterized in that the dot array of printing by the nozzles in the minute is inclined by an angle perpendicular to the direction of relative movement between the recording sheet wherein an ink jet recording head.

According to a third aspect of the present invention, ink is supplied to a plurality of nozzles arranged at regular intervals on a straight line, ink flow paths corresponding to the respective nozzles, ink droplet ejecting means, and respective ink flow paths. An ink jet recording head having a common liquid chamber and an ink supply port for controlling the driving of the ink droplet ejecting means, the control means are divided into a plurality of groups in apparent arrangement order. In each of the groups, for each of the nozzles divided by a predetermined number from the top of each group, each section is sequentially selected, and in the selected section, the nozzle is sequentially selected from the top for each selection of the section. And controls the interlaced driving so that one selected nozzle is driven in the direction in which the nozzles are arranged. , It is characterized in that the dot array of printing by the nozzles in the same segment is inclined by an angle perpendicular to the direction of relative movement between the recording paper ink jet recording head.

A plurality of recording heads mounted so that the arrangement direction of the nozzles is inclined by a predetermined angle may be arranged in a direction perpendicular to the relative movement direction between the recording medium and the recording head.

[0027]

In order to increase the repetition frequency at which ink droplets are repeatedly ejected, when an interlace driving method is employed in which a plurality of ink droplet ejecting means are jumped at predetermined intervals, the ink droplet ejecting means corresponding to a certain nozzle is driven. There is a time delay from when the ink droplet ejecting means corresponding to the adjacent nozzle is driven after being performed. According to the present invention, since the nozzle arrangement direction is inclined by an amount corresponding to the print shift amount due to the time delay, the linearity disturbance in the direction perpendicular to the relative movement direction of the recording medium and the recording head ( Jagged) does not occur.

The above-described driving method is applied to a case where a plurality of recording heads are connected in a direction perpendicular to the relative movement direction of the recording medium and the recording head to further improve the recording speed. Since the head is inclined by a predetermined angle defined by the driving method, the linearity in the direction perpendicular to the direction of relative movement between the recording medium and the recording head is not impaired.

Since the recording head is inclined with respect to the direction perpendicular to the direction of relative movement between the recording medium and the recording head,
The arrangement pitch of the nozzles and ink droplet ejecting means can be made larger than the pixel pitch determined by the printing density, and a high printing resolution can be accommodated without increasing the printhead manufacturing technology.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermal ink jet recording head used in the embodiment has the same structure as the ink jet recording head described in Japanese Patent Application Laid-Open No. 5-155020 described with reference to FIG. In this example, one recording head includes:
There are 64 nozzles used for printing at equal intervals on a straight line, and each of the 64 nozzles has a heater 7 in a corresponding flow path. No. 64 nozzles and heaters were sequentially set to NO. 1, NO. 2, ..., NO. A description will be given with the number 64. The number of nozzles provided in one recording head is 64, for example, and the number of nozzles of the recording head in the present invention is not limited to 64.

Before describing the embodiments, a driving method as a premise of the present invention will be described. 1 and 2 are explanatory diagrams of a heater driving order. FIG. 1 is an explanatory diagram of an example of an interlace driving method, and FIG. 2 is an explanatory diagram of a sequential driving method. In each case, 64 heaters are driven.

In the sequential driving method shown in FIG.
As shown in FIG.
In one printing cycle in the order of 1, 2, 3,..., 64, all the nozzles are driven by one scan, and the adjacent heaters are sequentially driven. FIG. 2B shows a drive voltage waveform. When this driving method is used, when the ink is resupplied (refilled) into the flow path of the nozzle that has ejected the ink droplet, the adjacent heaters are continuously driven, so that the ink refilling is performed at substantially the same time. The negative pressure of the ink in the ink reservoir is locally increased, and the ink refill speed is reduced. For this reason, as described above, the sequential driving method has a problem that the printing repetition frequency F cannot be increased. In addition, since the pressure of the bubble generated on the heater propagates to the adjacent flow path and causes crosstalk, and unnecessary meniscus fluctuation occurs in the nozzle portion, it is necessary to allow time for the meniscus fluctuation to sufficiently stop. The repetition frequency at which ink droplets can be ejected stably decreases.

FIG. 1 shows an example of the interlace driving method.
As shown in (A), as shown in FIG. 1,6,11, ..., 56,61,2,
7, ..., 62,3, ..., 63,4, ..., 6
, 60 are driven in this order. In this interlace driving method, the NO. Focusing on heater No. 1, NO. At the next timing after one heater is driven, the NO. Six heaters are driven. In this manner, intermittent nozzles are driven in one scan, and all nozzles are driven in five scans in one print cycle. FIG. 1B shows a drive voltage waveform.

As described above, the first heater No. No. 1 is driven at the next timing by being driven. The spatial distance to the 6 heaters (the number of heaters: 4 in this example) is M, and M + 1 is called the skip number. In addition, No. 1 is driven, and the adjacent NO. The number of heaters until two heaters are driven is represented by L (12 in this example). This L
Let +1 be called the interlace level.

As can be seen from FIG. 1, M and L are the same regardless of which heater is focused. In such an interlace system, in order to make M and L the same regardless of which heater is focused, the number of heaters N covered by one interlace in one cycle (here, equal to the total number of nozzles) 64), the relationship of N = (M + 1) × (L + 1) -1 needs to be established. Therefore, when this relationship is established, the interlace level is determined by the total number of nozzles and the number of jumps.

The tilt arrangement of the recording head will be described.
As described above, the direction of relative movement between the recording medium and the recording head is called the sub-scanning direction, and the direction perpendicular to the sub-scanning direction is called the main scanning direction. In this case, the relative moving speed V between the recording medium and the recording head is calculated. As shown in FIG. 1, the time required to advance the distance of one pixel is the total number of nozzles × t, where t is the time until the next heater is driven.
Assuming that the pixel pitch is P, V = P / 64t.

In the case of the sequential driving method, the relative movement amount between the recording medium and the recording head is one pixel during one printing cycle in which 64 nozzles are driven. Therefore, if the head is arranged so that the nozzle arrangement direction is perpendicular to the sub-scanning direction, the print pattern is inclined as described with reference to FIG. Referring to FIGS. 14 (B) and 14 (C), after the heater 7a corresponding to the nozzle 5a for printing the pixel 17a is driven, the heater corresponding to the nozzle 5b for printing the pixel 17b adjacent to the pixel 17a is driven. Is driven after t, the pixel 17b is printed at a position separated by V × t = P × (1/64) from the pixel 17a. Therefore,
By arranging the nozzle 5b adjacent to the nozzle 5a at a position shifted by P × (1/64), the pixel 17b is printed on the recording medium at a position which is linear in the main scanning direction. become. To realize this, the recording head may be tilted by θ in advance, and this θ
Can be obtained by θ = tan ⁻¹ (1/64), and in this case, it is about 0.895 °.

In the conventional interlace driving method, the relative movement amount between the recording medium and the recording head is one pixel during one printing cycle in which 64 nozzles are driven. Also in this driving method, the recording head can be arranged to be inclined by the angle described above. However, even if the recording head is arranged at an angle, the printing order changes, so that when a straight line is printed, disturbance of the linearity cannot be avoided as described with reference to FIG.

A first embodiment of the present invention will be described with reference to the above-mentioned conventional example. The order of driving the nozzles is shown in FIG.
The order is the same as described in.

Here, it is considered that the heads are arranged so that the nozzle arrangement direction is perpendicular to the sub-scanning direction. This will be described with reference to FIG. Since the heater corresponding to the nozzle adjacent to one nozzle a is driven after 13t,
The ink droplet ejected from the nozzle located at b1 adjacent to a is printed at the position of b2 separated by V × 13t = P × (13/64). Therefore, if the adjacent nozzle is arranged at the position of b3 shifted by 13P / 64, printing is performed at the position of b1 on the recording medium, and it is aligned with a in the main scanning direction. In order to realize this, as shown in FIG. 3, the recording head may be tilted by θ in advance, and θ can be obtained by θ = tan ⁻¹ (13/64). .48 ゜.

FIG. 4 schematically shows a part of a dot array on a recording paper used as a recording medium when all the 64 nozzles are ejected by the driving method shown in FIG.
For the sake of explanation, a case where the head is not intentionally tilted (the sub-scanning direction and the nozzle arrangement direction remain vertical) is shown. The scales in the vertical and horizontal directions are different, and the scale of the dot size is different from the actual scale.

As described above, according to the present invention, when one straight line is formed in the main scanning direction, ink ejected by, for example, 64 heaters driven during one printing cycle T (1 / F) is used. Rather than printing one straight line with dots by drops, in the case of the driving sequence shown in FIG. 1, one dot is formed by using ink droplets ejected from 64 nozzles during 13 printing cycles. It prints a straight line. For example, focusing on the straight line 20a, the straight line formed in the first printing cycle is No. No. 1, 2, 3, 4, and 5 nozzles. 6,7,8,
Straight line 2 printed at the first print cycle with nozzles 9 and 10
0a is printed on the extension of No. 0a.
The nozzles 11, 12, 13, 14, and 15 further perform printing on the extension of the straight line 20a printed in the second printing cycle, and similarly perform printing on the extension of the straight line 20a in the same manner. In the last thirteenth printing cycle, N
o. 61, 62, 63, 64 nozzles, the same straight line 20
a is printed over the extension of a
Two straight lines 20a are printed.

The dots within a certain printing cycle which are not used for printing this straight line are also used for the other straight lines 20b, 20c, 20d, 2
0e,... Are not wasted, and the printing of (13-1) is performed when the printing medium and the printing head perform printing by one relative movement in the sub-scanning direction. It only takes an extra period. If the repetition frequency F is 5 kHz, the twelve periods are 2.4 msec, which does not lower the printing speed at all. Consider the case where the recording head performs printing while moving by the carriage, and in one carriage return cycle,
It can be said that the printing time only increases by 2.4 msec.

FIG. 5 is a schematic diagram of a dot array when solid printing is performed by the interlace driving method. The numbers given as line numbers in the figure are lines perpendicular to the sub-scanning direction (lines in the main scanning direction)
, And each line has a length corresponding to the nozzle arrangement width. FIG. 9 shows a state in which printing is performed by the recording head having the above-described 64 nozzles, and the number shown above each of the five dots indicates the order of the printing cycle, and the first printing cycle To the (n + 12) th printing cycle. Therefore, the lower five dots of each number are dots to be printed in the printing cycle. In addition, since each line has an interval of one dot, there is no gap. However, in order to make the figure easier to understand, the lines are intentionally spaced and illustrated. As can be seen from this figure, when printing n lines in the sub-scanning direction, it is necessary to repeat the printing cycle of n + 12.

When the number of nozzles in one head is tilted by the tilt angle θ calculated from the interlace level, in order to realize a pixel pitch P to be printed on paper, the nozzle pitch P in the print head is required. Is Pn = P / cos θ. If the pixel density is 300 spi, the pixel pitch P is about 84.5 μm, and the nozzle pitch Pn is 86.2 μm, which is wider than this.

FIG. 6 shows a driving order in the second embodiment of the present invention. This is one in which the scanning direction is bent a plurality of times before driving the adjacent heater, and is called high-order interlace driving. Here, the case where the interlace level L + 1 = 11 and the number of jumps M + 1 = 35 is described. In this interlace, N = K = (L + 1) (M + 1) -1 holds where K = 6. This K is called an interlace order. That is, the interlace shown in FIG. 1A can be said to be an interlace in which the interlace order K is 1. Here, the number of heaters existing up to the heater driven at the next timing is 34 or 29. In the method described in FIG. 1, L + 1 = 1
3, L + 1 = 11 in this method, and the effect of avoiding the influence of meniscus vibration due to crosstalk in the adjacent nozzle is not significantly changed. However, the spatial distance (M + 1) of the heater driven at the next timing becomes larger in this method, and at a position where the bubble pressure generated by a certain heater is sufficiently attenuated, that is, in a state without unnecessary meniscus vibration. , Bubbles can be generated and ink droplets can be ejected. In this method, the angle θ at which the recording head is inclined is given by θ = tan ⁻¹ (11/64), and is about 9.75 °.

FIG. 7 is an explanatory view of a third embodiment of the heater driving method. In the driving method described in the first embodiment and the second embodiment, the number of heaters driven at exactly the same timing is one. However, in this embodiment, FIG.
, Two heaters are simultaneously driven. That is, No. The interlace level (L
+1) is 11 and the number of jumps (M + 1) is 3 K = 1
The interlaced driving method is applied. As shown in FIG. 7 (B), the same interlace driving method is performed at the same timing with the No. This is applied to heaters 33 to 64. Also in this case, one interlace is 1
The relationship of N × K = (M + 1) (L + 1) −1 is established when the number of heaters N covered in the cycle is 32. In this case, the angle θ at which the recording head is inclined is θ = tan ⁻¹ (11/32) = 18.97 °.

If this is expressed using the total number of nozzles N and the interlace level L + 1, then θ = tan ^-1 {(L + 1) / N}. In this case, a 300 spi pixel pitch of 8
For 4.5 μm, the nozzle pitch is about 89.4 μm.

The number of all nozzles N and the number of jumps M
Expressed as +1, θ = tan ⁻¹ {(N + 1) / N · (M + 1)}.

Next, a description will be given of a fourth embodiment in which the number of nozzles is increased to 264 in the ink jet recording head shown in FIG. In this case, the number of heaters to be simultaneously injected is 1, and an interlace of L + 1 = 53, M + 1 = 5, and K = 1 is applied. FIG. 8A shows the driving order, and FIG. 8B shows the driving voltage waveform. In this embodiment, the angle at which the recording head is inclined with respect to the main scanning direction is given by θ = tan ⁻¹ (53/264), and is about 11.35 °.

In the recording head of this embodiment, since the number of nozzles is large, as shown in FIG.
If the heater driven at the next timing is driven after the driving of one heater is completely completed, the time T (one printing cycle) required to drive the same heater again becomes very long. For example, assuming that one voltage pulse length is 2.4 μs and the time until driving at the next timing is 0.25 μs, t = 2.65 μs, and 1
The printing cycle is T = 264 × 2.65 = 699.6 μs, and the repetition frequency is about 1.4 kHz, which is far below the limit frequency upper limit.

In order to shorten the T, as in the driving method of the embodiment shown in FIG. 7, the same interlace drive is applied plurally in one head, and plural heaters are driven at the same time. In this case, if the simultaneous driving heater is 4,
T becomes 1/4 and F becomes 4 times. However, an embodiment using another method will be described here.

As shown in FIG. 8B, the number of heaters driven at exactly the same timing is one, but a certain voltage pulse and a part of the voltage pulse driven at the next timing are overlapped. Here, the time t from the start of applying a certain voltage pulse to the application of the next voltage pulse is 0.3 μm.
s. In this driving method, a voltage pulse is applied to a maximum of eight heaters at a certain time. In this way, T = 79.2 μs, and the maximum repetition frequency is about 12.6 kHz.

A plurality of the recording heads described above are connected,
A case corresponding to a wide printing width will be described.

FIG. 9 is a conceptual diagram of a head arrangement in a fifth embodiment of the ink jet recording apparatus of the present invention. In this embodiment, a plurality of heads are arranged so as to be connected. In the figure, reference numeral 22 denotes a nozzle group in each head,
Reference numeral 21 denotes a nozzle (for example, No. 1 nozzle) to be driven first in each nozzle group. Since the position of the nozzle (No. 1 nozzle) to be driven first is on the same side in each head, and the inclination angle θ of each nozzle group is the same, the same No. Are located in the same main scanning line direction. The interval between the nozzles at the opposite end of the adjacent nozzle group 22 is the pixel pitch P. The heaters corresponding to the respective nozzles have the same No. in each nozzle group. Are driven simultaneously. As described in each of the above-described embodiments, the driving order employs the interlace driving method.

FIG. 10 is a conceptual diagram of a head arrangement in a sixth embodiment of the ink jet recording apparatus of the present invention.
In this embodiment, as in the fifth embodiment, a plurality of heads are arranged so as to be joined together. However, the nozzle 21 to be driven first is located on the opposite side in the nozzle group 22 of the adjacent recording head. I have. Also in this embodiment, since the inclination angle θ of each nozzle group is the same, the same No. Are located in the same main scanning line direction. The interval between the nozzles at the opposite end of the adjacent nozzle group 22 is the pixel pitch P. The heaters corresponding to the respective nozzles have the same No. in each nozzle group. Are driven simultaneously. As for the driving order, an interlaced driving method is adopted as in the fifth embodiment.

When a plurality of recording heads are connected and arranged as in the fifth and sixth embodiments, each recording head is positioned at the same position in the main scanning direction so as to print within the same recording print width. It was explained that it was arranged in.

However, having 264 nozzles, L + 1
= 53 and M + 1 = 5 using a recording head to which interlace driving is applied, and when the inclination angle is small so that the inclination angle θ is 11.35 °, as shown in FIG. 9 and FIG. It is difficult to arrange the position of the nozzle driven first of the head on one straight line in the main scanning direction.

FIG. 11 is an explanatory view of the arrangement of recording heads in a modification of the fifth embodiment, and is an arrangement method suitable for a case where the inclination angle is small. In the figure, 18a, 18b, 1
8c, 18d, 18e are recording heads, 21a, 21b,
Nos. 21c, 21d and 21e are Nos. 1 nozzle, 22a, 2
2b, 22c, 22d, 22e are nozzle groups, 23a, 2
3b, 23c, 23d and 23e are joint portions.
As shown in FIG. In a so-called staggered arrangement in which the position of one nozzle is shifted by a distance d in the sub-scanning direction, the nozzle is inclined by an angle θ. With such an arrangement, the distance between the nozzles at both ends of each recording head and the ends of the recording heads can be made sufficiently large, and the ink reservoir can be made sufficiently large. Also, there is no need for high processing accuracy such as making the distance from the nozzles at both ends to the head end half the pixel pitch P. Of course, in this case, the recording head 1
The printing start timing of the recording head 8a and the recording head 18b must be shifted by the time during which the paper moves the distance d, but such printing control is very easy.

FIG. 12 is an explanatory view of the arrangement of recording heads in a modification of the sixth embodiment, and is an arrangement method suitable for a case where the inclination angle is small. In the figure, the same parts as those in FIG. In order to supply ink from the ink tank to the ink reservoir of the thermal ink jet recording head as described in FIG. 13, it is necessary to install a joint for connection with the outside at the ink supply port of the recording head. It is often located just above the supply port. Therefore, when the recording heads are connected as shown in FIG. 9, it is necessary to increase the distance d so that the joint 23c and the recording head 18b do not interfere with each other, and the entire print head in which a plurality of heads are connected becomes large. . In FIG. 12, since the joints of the adjacent heads are attached in opposite directions to each other, the distance d can be smaller than the arrangement of FIG.
The size of the device can be reduced.

In addition to the interlace order shown in the above embodiment, L,
The values of M and K can be appropriately selected. At this time, if the numbers N, L, and M are selected so that the inclination angle θ of the nozzle row becomes large, the staggered arrangement shown in FIGS. The print head can be further miniaturized. If the inclination angle θ is increased, the arrangement pitch of the nozzles and heaters can be made larger than the required pixel pitch, and the head production becomes easier. Further, when ink is ejected from a certain nozzle and ink is refilled from the ink reservoir to the ink flow path, if L is selected so that a bubble is generated from an adjacent heater, the bubble pressure from the adjacent heater can be reduced. And the repetition frequency can be increased.

In the above-described embodiment, a thermal ink jet system using a heater as an ink droplet ejecting means has been described as an example.
It is obvious that the present invention is applied to other types of ink jet recording methods. In the case of color printing, high-speed printing can be performed by applying the above-described method for each color.

[0063]

As is apparent from the above description, according to the present invention, each nozzle is divided into a predetermined number from the head, and each nozzle is divided into the selected nozzles. Each time is selected, the interlaced drive is controlled so that one nozzle selected sequentially from the head side is driven, and the arrangement of the nozzles is the dot arrangement of printing by nozzles in the same section. By being inclined by an angle perpendicular to the relative movement direction between the paper and the ink jet recording head, there is an effect that linearity in the main scanning direction is not impaired.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an example of an interlace driving method.

FIG. 2 is an explanatory diagram of a sequential driving method.

FIG. 3 is an explanatory diagram of an inclined arrangement of a recording head.

FIG. 4 is an explanatory diagram schematically showing a part of a dot array in a printing state according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram of a dot array in a case where solid printing is performed in the first embodiment.

FIG. 6 is an explanatory diagram showing a driving order in an ink jet recording apparatus according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram of a third embodiment of the ink jet recording apparatus of the present invention.

FIG. 8 is an explanatory diagram of a fourth embodiment of the ink jet recording apparatus of the present invention.

FIG. 9 is a conceptual diagram of a head arrangement in a fifth embodiment of the ink jet recording apparatus of the present invention.

FIG. 10 is a conceptual diagram of a head arrangement in a sixth embodiment of the ink jet recording apparatus of the present invention.

FIG. 11 is an explanatory diagram of an arrangement of recording heads in a modified example of the fifth embodiment of the ink jet recording apparatus of the present invention.

FIG. 12 is an explanatory diagram of the arrangement of recording heads in a modification of the sixth embodiment of the ink jet recording apparatus of the present invention.

13A and 13B show an example of a conventional thermal inkjet recording head, in which FIG. 13A is a cross-sectional view taken along a direction perpendicular to the axial direction of a channel groove, and FIG. 13B is a plan view taken along line BB of FIG. FIG. 3C is a front view as viewed from the nozzle side.

FIG. 14 is an explanatory diagram of a printing state of the sequential driving method.

FIG. 15 is an explanatory diagram of a printing state of an example of an interlace driving method.

FIG. 16 is a layout diagram of recording heads in a linear arrangement.

FIG. 17 is a layout diagram of a recording head in a staggered arrangement.

[Explanation of symbols]

1 is a channel substrate, 2 is a heater substrate, 3 is a channel groove,
4 is an ink reservoir, 5, 5a, 5b, 5c, 5d, 5
e is a nozzle, 6 is an unetched portion, 7, 7a, 7b, 7
Reference numerals c, 7d, and 7e denote heaters, 8 denotes an insulating layer, 9 denotes a thick resin layer, 10 denotes a first concave portion, 11 denotes a second concave portion, 12 denotes a partition, 13 denotes an ink droplet, 14 denotes a recording medium, and 15 denotes a recording medium. Ink supply port 16, drive pulse 17a, 17b, 17c, 1
7d and 17e are pixels, 18 is a recording head, 19 is an end nozzle, 20a, 20b, 20c, 20d and 20e are printed straight lines, and 21a, 21b, 21c, 21d and 21e are No. 1 nozzle, 22a, 22b, 22c, 22d, 2
2e is a nozzle group, 23a, 23b, 23c, 23d, 2
3e is a joint part.

Claims (3)

(57) [Claims] 1. A plurality of nozzles arranged at equal intervals on a straight line, an ink flow path corresponding to each nozzle, an ink droplet ejecting means, a common liquid chamber for supplying ink to each ink flow path, and ink. In an ink jet recording head having a supply port, and an ink jet recording apparatus having a control means for controlling the driving of the ink droplet ejecting means, the control means, for the nozzles that are apparently divided by a predetermined number from the top, each Sections are sequentially selected, and in the selected section, control is performed such that jump driving is performed such that one nozzle sequentially selected from the head is driven for each selection of the section, The direction in which the nozzles are arranged depends on the relative movement between the recording paper and the ink jet recording head. An ink jet recording apparatus characterized by being inclined by an angle perpendicular to the direction. 2. A plurality of nozzles arranged at equal intervals on a straight line, an ink flow path corresponding to each nozzle, an ink droplet ejecting means, a common liquid chamber for supplying ink to each ink flow path, and ink. In an ink jet recording head having a supply port, and an ink jet recording apparatus having a control means for controlling the driving of the ink droplet ejecting means, the control means, for the nozzles that are apparently divided by a predetermined number from the top, each The division is divided into the first half and the second half, and the respective divisions in the first half and the second half are alternately and sequentially selected. In the selected division, the division is sequentially selected from the head side for each selection of the division. Control is performed so that jump driving is performed such that one nozzle is driven, and the direction in which the nozzles are arranged is determined by printing by nozzles in the same section. Wherein the dot arrangement is inclined by an angle perpendicular to the relative movement direction of the recording paper and the ink jet recording head. 3. A plurality of nozzles arranged at equal intervals on a straight line, an ink flow path corresponding to each nozzle, an ink droplet ejecting means, a common liquid chamber for supplying ink to each ink flow path, and ink. In an ink jet recording head having a supply port, and an ink jet recording apparatus having a control means for controlling the driving of the ink droplet ejecting means, the control means is divided into a plurality of groups in apparent arrangement order, For each of the nozzles divided by a predetermined number from the top of the group, each section is sequentially selected, and in the selected section, one nozzle sequentially selected from the top for each selection of that section Are controlled so that the interlaced drive is performed so that the nozzles are driven. An ink jet recording apparatus characterized in that the dot arrangement for printing is tilted by an angle perpendicular to the relative movement direction between the recording paper and the ink jet recording head.