JPH10119283A - Recorder, method for driving recording head and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high quality image having a small dot shift by performing divisional driving in terms of a recorder, a method for driving a recording head and a recording medium. SOLUTION: A recording head wherein a plurality of recording elements are arranged is moved in a direction (a) and the recording elements are divided into (k) groups A1-A4 each having (n) blocks D1-D4 (k, n = positive integer numbers). Divisional printing is executed such that the recording elements are driven sequentially by each block during the moving of a head carriage. At that time, driving in each of the blocks D1-D4 is optimally performed in an order in which a difference between driving times of a first block D1 in a (j+1) group A2 and (n)th block D4 in (j) group A1 becomes smaller than a maximum difference between driving times of the first block D1 in the (j+1) group A2 and the other blocks D2, D3 in the (j) group A1. The orders of the driving in the inward and outward directions are opposed with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus, a recording head driving method, and a recording medium, and more particularly, to a recording apparatus and a recording apparatus for forming an image corresponding to an image signal by driving a plurality of recording elements in blocks. The present invention relates to a head driving method and a storage medium.

[0002]

2. Description of the Related Art In recent years, recording apparatuses having recording elements such as ink jet recording apparatuses, thermal transfer recording apparatuses, and thermal recording apparatuses have been used for various purposes.
Many technical improvements have been made. Among them, methods for improving the recording speed include a method of increasing the number of recording elements (for example, nozzles) in the recording head and a method of increasing the driving frequency. By increasing the number of printing elements, the area that can be printed in one scan can be increased, and by increasing the driving frequency, the scanning speed can be increased, and the printing speed can be improved.

However, when the number of print elements of the print head is increased, the current consumed in one scan increases in proportion to the number of print elements, and as a result, it is necessary to increase the power supply capacity, which increases the cost of the apparatus. There was a problem.

In order to solve this problem, what originally drive all the printing elements in the print head at the same time is divided into several blocks, and each block is separated by a small time difference t within a driving cycle. There has been proposed a block division driving method in which current consumption is reduced at a time by sequentially driving.

[0005]

However, in the conventional block division driving method of the recording head, the driving order of the recording elements is not optimized. As a result, the positional deviation of the adjacent dots in the main scanning direction is large. There was a problem that unevenness was noticeable.

FIGS. 7 and 8 are plan views showing print dot patterns formed by nozzles driven by a conventional recording head driving method.

The recording head has a plurality of nozzle groups each composed of a plurality of recording elements arranged in a direction substantially perpendicular to the main scanning direction. In FIG.
1, A2, A3, and A4 indicate dot rows recorded by one nozzle group during forward scanning. In FIG. 8, b indicates the backward scanning direction, and B1, B2, B3, and B4 indicate dot rows recorded by one nozzle group during backward scanning. The printing elements of each nozzle group are divided into blocks,
D2, D3, and D4 are first, second, third, and fourth, respectively.
3 shows a dot row recorded by a block. Although the dots are recorded on the recording material by the adjacent blocks as shown in FIGS. 7 and 8, due to the drive time difference between the dot rows D4 and D1, the positional deviation of the adjacent dots on the recording material as described above. d ₀ had occurred.

Also, a so-called reciprocal recording is performed in which recording is performed in both the reciprocating direction of the scanning direction of a head carriage equipped with a recording head for relatively scanning the recording material in a main scanning direction different from the arrangement direction of the recording elements. In this case, in order not to control the driving order of the blocks, dot rows A1 and A1 to be recorded at the time of forward scanning of the head carriage as shown in FIGS.
2, A3, A4 and dot rows B1, B recorded at the time of backward scanning
The recording patterns 2, 3, and 4 have a mirror image relationship that is line-symmetric with respect to the alternate long and short dash line, and there is a problem that uniformity of an image cannot be maintained during reciprocal recording.

The present invention has been made in view of the above-mentioned conventional problems, and is a recording apparatus and a recording head drive capable of solving the above-mentioned problems and obtaining a high-quality image while performing block division driving. It is intended to provide a method and a storage medium.

[0010]

According to another aspect of the present invention, there is provided an apparatus according to the present invention, comprising: a recording head having a plurality of recording elements arranged in a first direction; Moving means for moving the moving means in a second direction different from the first direction; and moving the moving means by dividing the plurality of recording elements into k groups (k and n are positive integers) each comprising n blocks. Wherein the division driving means comprises: a first block of a (j + 1) -th group and an n-th group of a j-th group in the first direction. The driving time difference from the block is (j)
+1) Each block is driven in a driving order that is smaller than the maximum driving time difference between the first block in the group and the other blocks in the j-th group.

Here, the driving order by the divided driving means is mod (k, n) + 1, mod (n-1 + k, n) at a constant period for the n blocks of the k group.
+1, mod (1 + k, n) +1, mod (n−2 +
(k, n) +1,... (k = 0, 1, 2,..., n−1).

Here, the n blocks can be driven with a time difference of m times a fixed time so that the maximum drive time difference does not exceed the fixed cycle. Here, the plurality of printing elements are driven by the divided driving means during the reciprocating movement of the moving means in the second direction, and are moved in the reverse order in the driving order during the movement in one direction. Inside, each block can be driven in the reverse order to the drive order.

Further, the recording head may be an ink jet recording head.

According to a sixth aspect of the present invention, there is provided a recording head having a plurality of recording elements arranged in a first direction, the recording head being different from the first direction.
And a dividing step in which the plurality of recording elements are divided into k groups (k and n are positive integers) each consisting of n blocks and sequentially driven for each of the blocks while the moving means is moving. And a driving time difference between the first block of the (j + 1) -th group and the n-th block of the j-th group in the first direction in the division driving step. Each block is driven in a drive order that is smaller than the maximum drive time difference between the first block in the (j + 1) group and the other blocks in the j-th group.

Here, the driving order in the divided driving step is such that mod (k, n) +1, mod (n-1 + k,
n) +1, mod (1 + k, n) +1, mod (n-2
+ K, n) +1,... (K = 0, 1, 2,..., N−1) n
It can also be optimized in any of the following order.

Here, in the division driving step,
The n blocks may be driven with a time difference of m times a predetermined time so that the maximum driving time difference does not exceed the predetermined period.

Here, in the division driving step,
The plurality of recording elements are driven during the reciprocating movement of the moving unit in the second direction. The driving order is in the driving order during the movement in one direction, and is opposite to the driving order during the movement in the reverse direction. The blocks may be driven in order.

Further, the recording head may be an ink jet recording head.

In order to achieve the above object, a storage medium according to the present invention as set forth in claim 11, further comprises a recording head having a plurality of recording elements arranged in a first direction, a recording head having a second arrangement different from the first direction. And a dividing step in which the plurality of recording elements are divided into k groups (k and n are positive integers) each consisting of n blocks and sequentially driven for each of the blocks while the moving means is moving. A storage medium storing a program of a recording head driving method including a driving step, wherein in the division driving step, a first block of a (j + 1) th group and an nth block of a jth group in the first direction are provided. Of the recording head driving method for driving each block in a driving order in which the driving time difference of the first block of the (j + 1) -th group is smaller than the maximum driving time difference of the other blocks of the j-th group. And characterized by storing the ram.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic perspective view of an ink jet recording apparatus to which the present invention is applied.

In the ink jet recording apparatus 1, reference numeral 2 denotes a head carriage, which has a nozzle row in which a plurality of nozzles (ink discharge ports) are arranged in the sub-scanning direction, and which has a recording head fixing lever for discharging ink droplets. 3 makes the head carriage 2 detachable. The head carriage 2 is provided with a connector for positioning and mounting the printhead and transmitting a signal for driving the printhead and the like, and is electrically connected to the printhead. In addition, the head carriage 2 positions and mounts the ink tank 4 so that the ink jet head communicates with the ink tank 4 to supply ink.

Reference numeral 5 denotes a scanning rail which extends in the main scanning direction of the head carriage 2 and slidably supports the head carriage 2. The head carriage 2 reciprocates in the directions of arrows a and b on the scanning rail 5 via a head carriage driving motor 6, a motor pulley 7, a driven pulley 8, and a timing belt 9. At this time, reciprocal printing can be performed by the print head. Also, 10, 11, and 12,
A transport roller pair 13 is disposed before and after the recording position of the recording head and nips and transports the recording material.

Reference numeral 14 denotes a recording material such as paper.
Is pressed against a platen that regulates the recording surface flat. At this time, the recording head mounted on the head carriage 2 protrudes downward from the head carriage 2 and is positioned between the recording material conveying rollers 11 and 13, and the discharge port forming surface of the recording head is pressed against the guide surface of the platen. Recording material 14
To face in parallel. The image data is transmitted from the electric circuit of the printer body to the recording head by a flexible cable.

In the ink jet recording apparatus 1, the recovery system unit 15 is disposed on the home position on the left side of FIG. In the recovery system unit 15, caps 16 and 17 are provided corresponding to a plurality of nozzle rows of the recording head, respectively, and can be moved up and down. When the head carriage 2 is at the home position, the head carriage 2 is joined to the recording head and capped, and the ink in the ejection openings of the recording head evaporates to increase the viscosity.
It prevents sticking and ejection failure.

The caps 16 and 17 are connected to the pump unit via tubes or the like, and in the event that the recording head fails to discharge, suction recovery performed by joining the cap and the recording head using the pump unit. Negative pressure is generated for processing and the like. The recovery unit 15 includes a wiper blade 1 formed of an elastic member such as rubber.
8 is provided to wipe off the ink droplets adhered to the ejection port surface and to clean it.

FIG. 2 is a block diagram showing a system configuration of the ink jet recording apparatus according to one embodiment of the present invention.

Reference numeral 20 denotes a bus line for transmitting an address signal, a control signal, and data inside the printing apparatus.
Denotes an image input unit for inputting an image signal. Reference numeral 22 denotes a CPU that controls the entire recording apparatus based on various programs in the R0M 23. In the CPU 22, R0M 23 stores a recording head movement control program, an error processing program, a recording operation program, a program for operating the CPU 22, and the like according to the method of the present invention. Reference numeral 24 denotes a RAM used as a work area for various programs in the ROM 23 and a temporary save area for error processing.

Reference numeral 25 denotes an image signal processing unit for performing signal processing of the input image signal obtained by the image input unit 21, and reference numeral 26 denotes an operation unit for performing operations such as recording start. An ejection timing control unit 29 controls the driving order of each nozzle of the recording head as described later, and optimally controls the dot position on the recording material. The sub-scanning unit 27 rotates the transport motor by a predetermined amount at a predetermined timing. The main scanning unit 28 rotates the head carriage driving motor 6 by a predetermined amount at a predetermined timing. Reference numeral 30 denotes a recording unit, which forms an image by discharging ink onto the recording material 14 by a recording head with a drive pulse at a timing described later.

Next, the recording head of the ink jet recording apparatus having the above-described configuration is configured such that four nozzle groups of 32 nozzles (total of 12 nozzles) are provided.
A recording head driving method for a multi-nozzle inkjet head having eight nozzles will be described. In the present embodiment, each nozzle group is divided into four blocks for every eight adjacent nozzles and driven. Here, the first block, the second block, the third block, and the fourth block are referred to as the first block, the second block, the third block, and the fourth block from the end block in the nozzle group of 32 nozzles. , A fourth group (four in total).

FIG. 3 is a timing chart showing the order of driving the recording head when the head carriage moves forward.

In FIG. 3, P1 is a drive pulse applied to the nozzles of the first block, P2 is a drive pulse applied to the nozzles of the second block, P3 is a drive pulse applied to the nozzles of the third block, and P4 is a fourth drive pulse. This represents a drive pulse applied to the nozzles of the block. T is the period of each drive pulse and takes a constant value. The blocks corresponding to each nozzle group are driven simultaneously.

As shown in FIG. 3, in the present embodiment, P4 is set to a high level at time t = 0 and then P4
However, P2 is set to a high level after 2Δt, and P3 is set to a high level after 3Δt, and each block is driven with a time difference. The maximum drive time difference 3Δt does not exceed the period T. Therefore, the four blocks of the dot rows A1, A2, A3, and A4 to be recorded at the time of forward scanning of the head carriage are driven in the order of the first block → the fourth block → the second block → the third block (1). Will be. In this order, assuming that n blocks are numbered from the end as 1, 2,..., N (here, n = 4), mod (k, n) +1, mod (n−
1 + k, n) + 1, mod (1 + k, n) + 1, mod
(N−2 + k, n) +1,..., (Where k = 0, 1,
2..., N−1; here, k = 0). Here, mod (a, b) represents a remainder when a is divided by b.

When the four blocks are divided and driven in this order, the fourth block is driven in the same order as the first block → second block → third block → fourth block shown in FIG. while dot position shift d ₀ generated between the fourth block and the (j + 1) th first block of group j group is away three blocks, the print result the dot position deviation inconspicuous as follows Will not be.

FIG. 4 is a plan view showing the landing positions of dots of ink droplets on the recording material when the four blocks are driven at the timing shown in FIG.

In FIG. 4, D1 is the nozzle row of the first block, D2 is the nozzle row of the second block,
Reference numeral 3 denotes a dot row recorded by the nozzle row of the third block, and D4 denotes a dot row recorded by the nozzle row of the fourth block. Also,
A1 is the first group of nozzle rows, A2 is the second group of nozzle rows, A3 is the third group of nozzle rows, and A4 is the fourth group of nozzle rows.
Each row of dots represents a dot row recorded by the nozzles of the group during forward scanning in the direction a of the head carriage.

As described above, the dot displacements d ₁ , d ₂ , d ₃ , and d ₄ in the a direction during the forward scan in FIG.
This corresponds to +1, -2, and -1 blocks, and the dot misalignment can be dispersed. Here, the sign “+” indicates that the printing dot position is shifted in the forward direction with respect to the previously driven block, and the sign “−” indicates that the printing dot position is shifted in the backward direction. Therefore, it is possible to suppress the dot position shift of the adjacent block to make it inconspicuous and to obtain a high-quality image while performing the block division driving.

The effect of the head driving sequence of the present invention increases as the number of blocks increases. For example, in the case of 8 blocks,
In the conventional head drive, a dot position shift of up to seven blocks occurs, but according to the drive order of the present invention,
Although illustration is omitted here, +2, +2, +2, +1 and-
It is possible to suppress the dot position shift of 2, -2, -2, -1 blocks.

Next, a description will be given of a so-called reciprocal printing in which a printing head is mounted and printing is performed in both directions of a scanning direction of a head carriage which scans a printing medium relatively in a direction different from the direction of a printing element array. . At the time of forward scanning, it is the same as in FIGS.

FIG. 5 is a timing chart showing the order of driving the recording heads when the head carriage moves backward.

In FIG. 5, P1 is a driving pulse applied to the nozzles of the first block, P2 is a driving pulse applied to the nozzles of the second block, P3 is a driving pulse applied to the nozzles of the third block, and P4 is a fourth driving pulse. This represents a drive pulse applied to the nozzles of the block. T is the period of each drive pulse and takes a constant value. The blocks corresponding to each nozzle group are driven simultaneously.

The driving sequence at the time of forward scanning is the sequence of (1) as shown in FIG. 3, while at the time of backward scanning, as shown in FIG. Δ
P2 after t, P4 after 2Δt, and P1 after 3Δt, respectively, and each block is driven with a time difference. The maximum drive time difference 3Δt does not exceed the period T. Therefore, the four blocks of the dot rows A1, A2, A3, and A4 to be recorded at the time of forward scanning of the head carriage are represented by (1) as shown in the third block → the second block → the fourth block → the first block (2). ) Is reversed and driving is performed in the reverse order.

FIG. 6 is a plan view showing the landing positions of dots of ink droplets on the recording material when the four blocks are driven at the timing shown in FIG.

In FIG. 6, D1 is the nozzle row of the first block, D2 is the nozzle row of the second block,
Reference numeral 3 denotes a dot row recorded by the nozzle row of the third block, and D4 denotes a dot row recorded by the nozzle row of the fourth block. Also,
B1 is a nozzle row of the first group, B2 is a nozzle row of the second group, B3 is a nozzle row of the third group, and B4 is a fourth row of nozzles.
Each row of dots represents a dot row recorded at the time of the backward scanning of the head carriage in the direction b by the nozzle rows of the group.

In the conventional case shown in FIGS. 7 and 8 in which the same scanning is performed in both the forward scan and the backward scan, since the scanning direction of the head carriage is different by 180 degrees, the dots recorded in the forward scan are different. Although the recorded patterns of the rows A1, A2, A3, and A4 and the dot rows B1, B2, B3, and B4 recorded at the time of the backward scanning are mirror images that are line-symmetric with respect to the alternate long and short dash line, image uniformity cannot be maintained. On the other hand, in the present embodiment, by driving in the order of (2) at the time of backward scanning, as shown in FIG. 6, dot rows A1, A2,.
A3, A4 and dot rows B1, B2,
The recording patterns of B3 and B4 can be arranged in the same order in the sub-scanning direction, and the uniformity of the reciprocating recording image can be maintained.

That is, the data of the adjacent block in the b direction
Offset d_Five, D₆, D₇, D ₈Are +2,
+1, -2, -1 blocks, and d_Five= D₁, D₆
= D_Two, D₇= D_Three, D₈= D_FourIt is. Of this deviation width
Dot row A recorded during forward scan with periodicity (repetition)
1, A2, A3, A4 and dot row B recorded at the time of backward scanning
1, B2, B3, and B4 are also stored, and
Uniform and high quality
There is an effect that an image can be obtained.

The method of the present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Needless to say, the method of the present invention can also be applied to a case where the method is achieved by supplying a program to a system or an apparatus. In this case, by reading out a storage medium storing a program represented by software for achieving the method of the present invention into a system or an apparatus, the system or apparatus can receive the effects of the method of the present invention. Become.

[0048]

As described above, according to the present invention, a recording head having a plurality of recording elements arranged in a first direction is moved in a second direction, and a plurality of recording elements are respectively moved to n.
The first block of the (j + 1) th group in the first direction at the time of divided driving in which the driving unit is divided into k groups (k and n are positive integers) and sequentially driven for each block while the moving unit is moving. And the driving time difference between the n-th block of the j-th group is (j + 1)
Since each block is optimized so as to be driven in a driving order that is smaller than the maximum driving time difference between the first block of the group and the other blocks of the j-th group, and the driving order is reversed in each of the reciprocating directions, This has the effect of minimizing the dot displacement while performing the division drive, and obtaining a uniform and high-quality image regardless of the moving direction of the recording head.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a block diagram illustrating a system configuration of the inkjet recording apparatus according to the embodiment of the present invention.

FIG. 3 is a timing chart of a recording head driving method during forward movement of a head carriage according to an embodiment of the present invention.

FIG. 4 is a plan view showing a pattern of print dots at the time of forward scanning by nozzles driven by the print head driving method according to one embodiment of the present invention.

FIG. 5 is a timing chart of a printhead driving method at the time of head carriage return movement according to an embodiment of the present invention.

FIG. 6 is a plan view showing a print dot pattern at the time of backward scanning by a nozzle driven by the print head driving method according to one embodiment of the present invention.

FIG. 7 is a plan view showing a pattern of print dots at the time of forward scanning by nozzles driven by a conventional recording head driving method.

FIG. 8 is a plan view showing a print dot pattern at the time of re-scanning by nozzles driven by a conventional print head driving method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 inkjet recording device 2 head carriage 3 recording head fixing lever 4 ink tank 5 scanning rail 6 head carriage driving motor 7 motor pulley 8 driven pulley 9 timing belt 14 recording material 15 recovery system unit 16, 17 cap 18 wiper blade 20 bus line 21 image input unit 22 CPU 23 ROM 24 RAM 25 image signal processing unit 26 operation unit 27 sub-scanning unit 28 main scanning unit 29 ejection timing control unit 30 recording unit

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[Procedure amendment]

[Submission date] December 19, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 7

[Correction method] Change

[Correction contents]

FIG. 7

Claims (11)

[Claims] A recording head having a plurality of recording elements arranged in a first direction; moving means for moving the recording head in a second direction different from the first direction; and the plurality of recording elements. To k groups (k, n
Is a positive integer) and divided driving means for sequentially driving each block while the moving means is moving is provided. The driving time difference between the first block of the (j + 1) group and the n-th block of the j-th group is the difference between the first block of the (j + 1) -th group and the j-th block.
A printing apparatus, wherein each block is driven in a drive order that is smaller than a maximum drive time difference between the group and other blocks. 2. The driving sequence by the divided driving means is such that m is performed at a constant cycle for the n blocks in the k group.
od (k, n) +1, mod (n-1 + k, n) +1,
mod (1 + k, n) +1, mod (n-2 + k, n)
2. The recording apparatus according to claim 1, wherein optimization is performed in any one of n types of +1,... (K = 0, 1, 2,..., N−1). 3. The divided driving means drives the n blocks with a time difference of m times a fixed time so that the maximum drive time difference does not exceed the fixed cycle. Recording device. 4. The plurality of printing elements are driven by the divided driving means during reciprocation of the moving means in the second direction, and in the driving order during movement in one direction and in the opposite direction during movement in one direction. 4. The recording apparatus according to claim 1, wherein the respective blocks are driven in an order reverse to the driving order during the movement of the recording medium. 5. The recording apparatus according to claim 1, wherein the recording head is an ink jet recording head. 6. A moving step of moving a recording head having a plurality of recording elements arranged in a first direction in a second direction different from the first direction, and moving the plurality of recording elements from n blocks. A division driving step of dividing the group into k groups (k and n are positive integers) and sequentially driving each block while the movement unit is moving. The driving time difference between the first block of the (j + 1) -th group and the n-th block of the j-th group in the first direction is different from that of the first block of the (j + 1) -th group and the other blocks of the j-th group. A driving order for driving each block in a driving order that is smaller than the maximum driving time difference. 7. The driving sequence in the divided driving step is such that mod (k, n) +1, mod (n−1 + k, n) at a constant period for the n blocks in the k group.
+1, mod (1 + k, n) +1, mod (n−2 +
7. The printhead driving method according to claim 6, wherein the optimization is performed in any one of n orders of (k, n) +1,... (k = 0, 1, 2,..., n-1). 8. The divided drive step according to claim 6, wherein the n blocks are driven with a time difference of m times a fixed time so that the maximum drive time difference does not exceed the fixed cycle. Recording head driving method. 9. The method according to claim 1, wherein in the dividing drive step, the plurality of recording elements are driven during reciprocation of the moving unit in the second direction, and in the driving order during movement in one direction.
9. The apparatus according to claim 6, wherein the respective blocks are driven in an order reverse to the driving order during the movement in the reverse direction.
The recording head driving method according to any one of the above. 10. The printhead driving method according to claim 6, wherein said printhead is an ink jet printhead. 11. A moving step of moving a recording head having a plurality of recording elements arranged in a first direction in a second direction different from the first direction, and moving the plurality of recording elements from n blocks. K groups (k and n are positive integers)
And a division driving step of sequentially driving each of the blocks during the movement of the moving means, wherein a program of the recording head driving method is stored. The driving time difference between the first block of the (j + 1) th group and the nth block of the jth group is larger than the maximum driving time difference between the first block of the (j + 1) th group and the other blocks of the jth group. A storage medium storing a program for a recording head driving method for driving each block in a driving order that also reduces the size.