JP3427847B2 - Recording device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention records a character or an image by moving a recording head in which a plurality of recording elements are arranged in the sub-scanning direction in the width direction of the recording paper and feeding the recording paper by a constant width. The present invention relates to a serial printing type recording device.

[0002]

2. Description of the Related Art A serial recording device is constructed as shown in FIG. That is, in the figure, reference numeral 1 is a recording head, and a plurality of recording elements 11 are arranged in the sub-scanning direction Y at regular equal intervals p. 2 is a carriage,
A recording head 1 is mounted. The carriage 2 is driven by a carriage motor 21 via a timing belt 24, and moves in the main scanning direction (a direction perpendicular to the paper surface in the figure) by the guide shafts 22 and 23. A paper feed drive roller 3 is arranged in front of the recording head 1. Reference numerals 321 and 322 denote paper feed driven rollers, which are pressed by the paper feed drive roller 3 with the recording medium 8 interposed therebetween. The recording medium 8 is wound around the paper feed drive roller 3 by the paper feed driven rollers 321 and 322. The paper feed drive roller 3 has a shaft portion 34 at the center, and is rotatably supported by a frame 41 via a bearing 33 that rotatably engages with the shaft portion 34. Shaft 34 of paper feed drive roller 3
A drive roller gear 31 is coupled to one end of the. The drive roller gear 31 is a paper feed motor gear 5 that forms a transmission means.
1 directly engaged, or the paper feed motor gear 5
1 and is engaged with an intermediate reduction gear forming a transmission means for multistage reduction. The paper feed motor gear 51 is coupled to the paper feed motor 5.

In such a printing apparatus, when printing a continuous pattern such as an image, the carriage 2 carrying the printing head 1 is moved in the main scanning direction,
A dot is recorded on the recording medium 8 by selectively driving the recording element 11 of the moving recording head 1 to form a first recording area (hereinafter referred to as a recording band) on the recording medium 8.

The paper feed motor 5 causes the paper feed drive roller 3 to move over the entire length of the recording head 1 in the sub-scanning direction (the recording element 11).
Is wound around the paper feed drive roller 3 by rotating the paper feed drive roller 3 by a constant angle θ determined by the distance between the elements in the sub-scanning direction is p and the number of the elements is p × n) and the diameter of the paper feed drive roller 3. The recording medium 8 is conveyed in the sub-scanning direction by the entire length of the recording head 1.

Once again, the recording head 1 is reversely moved in the main scanning direction to selectively drive the recording element during movement, thereby forming a second recording band adjacent to the first recording band. Similarly, the conveyance of the recording medium 8 in the sub-scanning direction and the movement of the recording head 1 in the main scanning direction are repeated, and the recording for one page is completed.

[0006]

However, the paper feed drive roller 3 does not rotate by a certain angle .theta. Due to the error of the drive means and the transmission means (for example, the stop position error of the paper feed motor 5 and the backlash error of the transmission gear). Even if the paper feed drive roller 3 is rotated by a certain angle θ due to an unavoidable error in manufacturing the paper feed drive roller 3 (for example, outer diameter dimension error or eccentricity error) that causes a difference in the amount of conveyance of the recording medium 8. A minute difference between the recording medium 8 and the paper feed drive roller 3 is caused by a difference in the type or state of the recording medium 8 (for example, a difference in bending strength, a surface friction coefficient, or a moisture absorption degree) that causes a difference in the conveyance amount of the recording medium 8. The gap between adjacent recording bands is defined for the reason that there is a difference in the amount of slippage and a difference in the amount of conveyance of the recording medium 8 even if the paper feed drive roller 3 of the correct size rotates by a certain angle θ. Amount (record van Recording dot interval of the inner, i.e. the inter-element spacing p of the recording element 11 arranged at equal intervals)
There is a problem that a line or gray (hereinafter referred to as banding) in the main scanning direction of the recording head is generated in a character or an image extending over the recording band as it becomes narrower or enlarged and the recording quality deteriorates. The present invention has been made in view of the above problems, and an object of the present invention is to provide a recording apparatus with high print quality by reducing the contrast of banding caused by scanning of the recording head. is there.

[0007]

In order to achieve the above object, the recording apparatus of the present invention moves a recording head having a plurality of recording elements arranged in the sub-scanning direction in the main scanning direction, and prints a recording sheet. In a recording apparatus that performs recording by feeding paper by a constant width, the number of recording elements of the recording head is n, the interval between the first recording element and the second recording element is p1, the second recording element and the third recording element are the same. The distance from the recording element is p2, (n-
1) The interval between the 1st recording element and the nth recording element is pn-
When set to 1, the average spacing (p1 + p2 + ... + pn-1) / (n-1) between each element in the sub-scanning direction of all recording elements
There is the recording elements arranged randomly as equal to the constant reference interval p predetermined, and the upper limit of the distance difference between the SL recording element becomes less transport error of the sheet feeding mechanism.

[0008]

Even if banding occurs at the boundary of the recording band due to an error in the amount of conveyance of the recording medium, the recording dots have unequal intervals in the sub-scanning direction. And banding becomes difficult to perceive.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below based on the illustrated embodiments. 1 is a perspective view showing a recording head of a recording apparatus of the present invention, FIG. 2 is a sectional view showing an embodiment of the recording apparatus of the present invention, and FIG. 3 is a perspective view thereof.

In these drawings, reference numeral 1 in the drawings is a recording head, and an ink jet head, a thermal head, a wire dot head, or the like can be applied. In the present embodiment, the ink jet head will be described as an example. The recording head 1 includes a plurality of recording elements 11 # 1 to #n arranged in the sub-scanning direction Y. Recording element 1 of recording head 1
1 is a plurality of nozzles 13 provided on the nozzle plate 12.
And a piezoelectric element or a heating element (not shown) arranged corresponding to each nozzle 13, and ink is ejected from the nozzle 13 by applying a drive voltage. The plurality of recording elements 11 arranged in the sub-scanning direction that configure the recording head 1 are selected in pitch so that the intervals in the sub-scanning direction are not uniform, as described later. The recording elements 11 may be arranged in a single row to obtain inter-element spacing in the sub-scanning direction, or the elements may be arranged in a plurality of rows in a staggered manner so that the inter-element spacing in the sub-scanning direction is increased by the plurality of rows of elements. You may get it.

Reference numeral 2 is a carriage on which the recording head 1 is fixedly mounted. The carriage 2 is a carriage motor 21.
As a result, it is driven via the timing belt 24 and moves in the main scanning direction X along the guide shafts 22 and 23.

A paper feed drive roller 3 is arranged upstream of the recording head 1 in the path of the recording medium 8. In the present embodiment, the outer diameter (outermost diameter) d of the paper feed drive roller 3 is about 3 mm, which is very small. The paper feed drive roller 3 has a shaft portion 34 smaller than the outermost diameter, and the shaft portion 34 is rotatably supported by a plurality of bearings 33 provided on a support plate 43. The paper feed drive roller 3 engages with one or more paper feed driven rollers 32 that press the outermost diameter portion of the paper feed drive roller 3 from the opposite side of the bearing 33 by a spring (not shown), and sandwiches the recording medium 8. The recording medium 8 is conveyed in the sub-scanning direction Y by rotating at. The paper feed drive roller 3 needs to have a high bending strength, a low friction coefficient with respect to the bearing 33, and a high friction coefficient with respect to the recording medium 8. For example, the metal shaft is partially coated with a thin ceramic or the like. Those that are suitable are preferred.

A drive roller gear 31 is connected to one end of the paper feed drive roller 3. In this embodiment, the drive roller gear 31 has a relatively large pitch circle diameter D of about 40 mm, and the ratio D to the outer diameter of the paper feed drive roller 3 is D.
/ D was set to a large ratio of 10 or more.

Reference numeral 5 denotes a paper feed motor, to which a paper feed motor gear 51 which is engaged with the drive roller gear 31 and serves as a transmission means is fixed. The drive roller gear 31 and the drive roller gear 31 are fixed.
The paper feed drive roller 3 connected with Ratio of number of teeth between drive roller gear 31 and paper feed motor gear 51 (reduction ratio)
Is optional. In addition, although the deceleration is a single-stage deceleration in this embodiment, the intermediate deceleration gear (not shown) serving as a multi-stage deceleration transmission means is interposed between the paper feed motor gear 51 and the drive roller gear 31 to achieve the multi-stage deceleration. It is also possible to do so. The paper feed motor 5 is of a general type, for example, 4 phase 48
A stepping motor having poles, 96 poles, 200 poles or the like can be applied. The carry amount (paper feed resolution) of the recording medium 8 per step of the paper feed motor 5 is the number of poles of the paper feed motor 5, the driving method of the paper feed motor 5, and the deceleration from the paper feed motor 5 to the drive roller gear 31. The ratio is determined by the combination of the outer diameters of the paper feed drive rollers 3. In this embodiment, the paper feed resolution is about 10 μm.

Reference numeral 6 denotes a paper feed roller, which has a built-in one-way clutch (not shown), is driven to rotate in only one direction by a paper feed roller shaft 64, and stores the recording medium 8 stored in a paper feed tray 65 in the recording apparatus. Send it to the paper feeder. A paper feed gear 63 is coupled to the paper feed roller shaft 64.

Reference numeral 61 denotes a paper feed motor, and a paper feed motor gear 62 engaging with a paper feed gear 63 is fixed to the paper feed roller 6.
To drive. A power switching mechanism is provided to switch the engagement of the paper feed motor gear 51 between the paper feed gear 63 and the drive roller gear 31 depending on the rotation direction of the paper feed motor 5, thereby eliminating the paper feed motor 61. It is also possible.

A paper edge sensor 7 detects the position of the end surface of the recording medium 8. Further, in order to discharge the recording medium 8 after recording, a pair of discharging rollers 35 and 36 may be provided on the downstream side of the path of the recording medium 8 with respect to the recording head 1.

Next, the operation of the recording apparatus having the above structure will be described. Feeding motor 6 when print data is received
1 starts rotation for feeding paper. The paper feed roller 6 is driven by the rotation of the paper feed motor 61, one recording medium 8 stored in the paper feed tray 65 is selected, and the paper feed drive roller 3 is selected.
And the paper feed driven roller 32. For the selected recording medium 8, when the leading edge of the recording medium 8 is detected by the paper edge sensor 7 between the paper feed roller 6 and the paper feed drive roller 3, the leading edge of the recording medium 8 is fed from that position. It is further fed by a fixed amount until it reaches the drive roller 3.
The front end of the recording medium 8 is pressed against the tangent portion between the paper feed drive roller 3 and the paper feed driven roller 32, and the rotation of the paper feed motor 61 is stopped in a state where the skew is corrected and the paper feed operation is completed. .

Next, the paper feed motor 5 starts to rotate so as to locate the recording medium 8. The rotation of the paper feed motor 5 drives the paper feed drive roller 3. The recording medium 8 is sandwiched between the paper feed driving roller 3 and the paper feed driven roller 32 and is fed out, and it faces the recording head 1, and the cueing operation is completed. The paper feed roller 6 idles in the drawing direction of the recording medium 8 by a built-in one-way clutch, and the recording medium 8 is drawn from the paper feeding tray 65 with a small load.

After the recording medium 8 is fed and the cueing operation is completed as described above, the carriage motor 2 is driven. The carriage 2 moves in the main scanning direction to move the carriage 2.
After the recording element 11 of the recording head 1 mounted on the recording head reaches the recording area in the main scanning direction, the recording element 1 is recorded according to the recording data.
1 is selectively driven to record an arbitrary character or image for one recording band in the recording area of the recording medium 8 in the main scanning direction.

After the printing of one recording band is completed, the driving of the carriage motor 2 is stopped, the paper feeding motor 5 is driven, and the recording medium 8 is recorded by the rotation of the paper feeding drive roller 3. 11 is conveyed by the entire length in the sub-scanning direction. After that, the carriage motor 2 is reversely driven to move the recording head 1 in the opposite direction, and the next recording band is printed adjacent to the recording band printed immediately before. Less than,
The conveyance operation of the recording medium 8 in the sub-scanning direction, the movement operation of the recording head 1 in the main scanning direction, and the recording operation are repeated.

When the recording approaches the end of the recording medium 8, the end of the recording medium 8 passes the paper edge sensor 7, and the paper edge sensor 7
Thus, the end of the recording medium 8 is detected. After that, the transport operation of the recording medium 8, the moving operation of the recording head 1 and the recording operation are repeated until the final band allocated by the end of the recording medium 8 is recorded, and the recording for one page is completed.

Here, the conveyance accuracy of the recording medium in the recording apparatus of this embodiment will be described. In this configuration,
Since the ratio D / d of the pitch circle diameter D of the drive roller gear 31 and the outer diameter d of the paper feed drive roller 3 is set to be sufficiently large, the pitch circle of the drive roller gear 31 shown in FIG. The amount 82 of the error of the driving means or the transmitting means (for example, the stop position error of the paper feed motor 5, the backlash error of the transmission gear, etc.) that occurs on the outer circumference of the paper feed drive roller 3 is reduced by the diameter ratio D / d. Is reduced to 81. Therefore, the amount of the recording medium 8 that is conveyed in close contact with the outer periphery of the paper feed drive roller 3 by the rotation of the paper feed drive roller 3 is highly accurate.

Further, in this configuration, since the paper feed drive roller 3 has a very small diameter, the moment of inertia is extremely small, and it is possible to accurately control a predetermined amount of rotation with high followability. .

Further, an error in the amount of conveyance of the recording medium 8 due to an outer diameter dimension error of the paper feed drive roller 3 can be corrected by adjusting the number of drive steps of the paper feed motor 5. That is, with respect to the number of drive steps of the paper feed motor 5 corresponding to the conveyance operation of the recording medium 8 by a predetermined amount, the paper feed drive roller 3 causes insufficient feeding (thinner than the target size).
Is corrected by adding the number of drive steps corresponding to the shortage amount, and reducing the number of drive steps corresponding to the excessive amount for the paper feed drive roller 3 that causes excessive feeding (thicker than the target size). it can. In this embodiment, the number of drive steps of the paper feed motor 5 corresponding to the conveyance operation of the recording medium 8 by a predetermined amount is set to be large (the paper feeding resolution is fine), and the conveyance accuracy of the recording medium 8 is set to ± 20 μm. I was able to hold it down.

Next, the structure of the recording head 1 will be described, for example, in which a predetermined interval (a reference interval p between elements described later) of the recording elements 11 in the sub-scanning direction is 1/300 inch and the number n of the recording elements 11 is n.
= 64 (nozzles) will be described as an example.

For the sake of explanation, the distance between the first element # 1 and the second element # 2 of the recording element 11 is p1, the distance between the second element # 2 and the third element # 3 is p2, ( n-
The interval between the 1) -th element # (n-1) and the n-th element #n is pn-1, and an arbitrary (i-1) -th element # (i-
The distance between 1) and the i-th element #i is represented by p i -1, and the reference interval between the elements, which is a preset reference resolution in the sub-scanning direction of the recording apparatus, is represented by p 1.

In the present embodiment, the arrangement of the recording elements 11 is determined as follows in consideration of the arbitrary inter-element spacing pi-1 being different from the reference spacing p in at least two locations.

First, it was determined that the average value of the arbitrary element-to-element spacing pi-1 was equal to the reference spacing p between the elements. That is, (p1 + p2 + ... + pn-1) /
The first condition was that (n-1) = p.

Further, the specific numerical value of the arbitrary element-to-element spacing pi-1 of the recording element 11 was randomly determined with the upper limit being a value slightly smaller than the carrying accuracy of the paper feeding mechanism. As an example, for example, 12 μm is set as the upper limit, and the deviation amount with respect to the reference interval p between the elements is +12 μm, +8.
μm, +4 μm, 0 μm, −4 μm, −8 μm, −12
.mu.m was set, each of the above deviation amounts was assigned to seven types of numbers from 1 to 7, and the intervals between the respective elements of the recording element 11 were provisionally determined using a random number table. Furthermore, in order to meet the first condition, the spacing between the elements thus obtained,
With some correction, the arrangement of the recording elements 11 in the sub-scanning direction was determined. As an example, in contrast to the above-mentioned reference distance p between elements of the recording head 1 of p = 1/300 inch≈85 μm, in the present embodiment, the distance between elements in the sub-scanning direction is p1 = 97 μm p2 = 89 μm. p3 = 81 μm p4 = 85 μm p5 = 93 μm p6 = 81 μm p7 = 77 μm p8 = 89 μm p9 = 85 μm p10 = 77 μm p11 = 89 μm p12 = 77 μm p13 = 85 μm ... p51 = 73 μm p53 = 81 μm p52 = 81 μm p52 = 81 μm p52 77 μm p56 = 89 μm p57 = 89 μm p58 = 85 μm p59 = 93 μm p60 = 89 μm p61 = 93 μm p62 = 81 μm p63 = 85 μm.

FIG. 5A shows an example of recording by the present recording element array, and FIG. 5B is an example of recording by a conventional recording head in which all recording elements are arranged at equal intervals. In each case, recording is performed by the lower elements # 57 to # 64 of the recording head 1 when recording a certain band, and then the recording medium 8 is conveyed and the upper element # 1 of the recording head 1 when recording the next band. To # 8 show recordings. In transporting the recording medium 8,
It is assumed that both have a transport error of +20 μm. That is, the distance between the recording dots of the lowermost element # 64 of the upper band and the recording dots of the uppermost element # 1 of the lower band is about 105 μm.

In the recording by the recording head of this embodiment shown in FIG. 5A, dots are formed slightly in the sub-scanning direction in the recording bands, so that the banding contrast generated between the recording bands is lowered. Are difficult to identify. On the other hand, in the recording example using the conventional recording head shown in FIG. 5B, banding regularly occurs at the boundaries of the recording bands, so that the banding contrast is high and very conspicuous.

Next, a second embodiment of the arrangement of the recording elements 11 in the sub-scanning direction will be shown. In this embodiment, in determining the arbitrary inter-element spacing pi-1, consideration was added in advance so that more values close to the reference spacing p appear. Further, similarly, the deviation amount with respect to the reference interval p is randomly determined with a value slightly smaller than the conveyance accuracy of the paper feeding mechanism as an upper limit. That is, for example, the upper limit is set to 12 μm, and the reference interval p
+ 8μm, + 4μm, + 2μ
m, 0 μm, 0 μm, -2 μm, -4 μm, -8 μm,
Nine patterns of + or -12 μm were set, each of the above deviation amounts was assigned to nine types of numbers from 1 to 9, and the array order was determined by the numerical sequence of the random number table using the random number table.
For a large deviation amount of 12 μm, + or − is collectively set and the appearance frequency is reduced to the other half, and +/− is determined again by the random number table. In addition, the appearance frequency of the deviation amount of 0 μm is
Doubled. Furthermore, +2, which is a value close to the reference interval p
μm and −2 μm are added. The intervals between the respective elements of the recording element 11 are provisionally set. Furthermore, the spacing between the respective elements thus obtained has the first condition (p1 + p2 + ... + p
A partial correction was made so as to match n-1) / (n-1) = p, and the arrangement of the recording elements 11 in the sub-scanning direction was determined.

As an example, for the above-mentioned reference interval p between the elements of the recording head 1, p = 1/300 inch≈85 μm,
In this embodiment, the intervals between the respective elements in the sub-scanning direction are p1 = 93 μm p2 = 85 μm p3 = 83 μm p4 = 85 μm p5 = 93 μm p6 = 89 μm p7 = 81 μm p8 = 83 μm p9 = 85 μm p11 = 85 μm p p12 = 83 μm p13 = 73 μm ... p51 = 87 μm p52 = 97 μm p53 = 85 μm p54 = 85 μm p55 = 81 μm p56 = 87 μm p57 = 87 μm p58 = 83 μm p59 = 77 μm p60 = 85 μm p61 = 85 μm p62 = 81 μm p62 It was

According to this method, with respect to the intervals between the elements in the band, it is difficult for abrupt changes in the intervals between the adjacent elements. Therefore, the print dots can be arranged in a more natural manner in the sub-scanning direction, and the print quality is further improved.

Next, a third embodiment of the arrangement of the recording elements 11 in the sub-scanning direction will be shown. In this embodiment,
An interval between each two elements at both ends of the recording element 11, that is, an interval p1 between the recording elements # 1 and # 2 and an interval p63 between the recording elements # 63 and # 64 (recording elements # (n-1) and #n). Pn-1) is arranged equal to the reference interval p, and the other elements are arranged unequally in the same manner as in the second embodiment.

According to this method, the recording dot by the lowermost element # 64 of the upper band and the uppermost element # of the lower band, which can be arranged with a relatively large deviation from the reference interval p due to the transport error of the recording medium 8. 1 and the recording dots on both sides of the recording dot (the upper band element #
The recording dots of 63 and the recording dots of the element # 2 of the lower band) can be arranged at the reference interval p. Therefore, the reference interval p is set at the connecting portion between the bands.
And large deviations overlap (+20 due to transport error, for example)
Misalignment of μm and shift amount of recording element array +8 to +12 μm
Overlap, or a deviation of -20 μm due to a transport error and the shift amount of the recording element array −8 to −12 μm overlap.)
The recording quality can be further improved particularly in a recording pattern in which recording dots are arranged every other dot.

The inventor of the present invention provided a recording medium printed by the recording apparatus of the third embodiment to a blind test of 20 monitors, and from 18 persons, the recording quality by the apparatus of this embodiment is better. 15 of them evaluated that there was a difference in the perception level of banding. From this, it was confirmed that the present invention is useful for improving print quality.

Furthermore, as another embodiment, the recording apparatus of the present invention can be realized by using a thermal head. The present inventor manufactured a thermal head with a standard resolution p = 1/360 inch and the number of elements n = 64, and the intervals between the elements were unequal. Even if the heating resistors, which are the recording elements of the thermal head, are arranged at unequal intervals, there is no particular change in the basic characteristics, such as variations in the resistance value of each heating resistor,
It was possible to put it to practical use. The recording quality was also sufficient.

The recording apparatus of the present invention further comprises another head,
For example, it can be easily realized by using a wire dot head.

The array of the n recording elements 11 of the recording head 1 has an average value (p1 + p2 +.
.. + pn-1) / (n-1) is set equal to the preset reference inter-element spacing p, and the reference inter-element spacing p is set to an arbitrary value, thereby making it compatible with any conventional recording head You can get sex.

Further, for example, in order to obtain the recording element array of the present invention in an ink jet head, among the components of the head, the nozzle 1 provided on the nozzle plate 12 is used.
It is only necessary to slightly change the hole position of No. 3, and in the thermal head, it is only necessary to slightly change the position of the heating elements that are collectively fired on the glass glaze. In any case, the present invention can be implemented without any increase in cost.

In the description of the above embodiment, an example in which the intervals between the recording elements 11 are arranged randomly is shown, but of course, they may be arranged regularly, or intentionally changed. You may put and arrange. For example, it may be changed with respect to the reference interval p of the intervals between the elements in response to the fluctuation of 1 / f which is considered to be comfortable to humans.

Further, the reference resolution and the reference element interval p and the amount of each element interval in the arrangement of the recording elements 11 can be appropriately selected according to the print resolution.

[0045]

As described above, according to the present invention,
Since the intervals between the respective elements in the sub-scanning direction of the recording elements are arranged at unequal intervals, the intervals of the recording dots in the recording band in the sub-scanning direction are random, and occur between the recording bands. The banding contrast is relatively lowered and is less perceptible, and print quality can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a recording head used in a recording apparatus of the present invention.

FIG. 2 is a sectional view showing a configuration of an embodiment of a recording apparatus of the present invention.

FIG. 3 is a perspective view of the recording apparatus shown in FIG.

FIG. 4 is a diagram for explaining a conveyance error in the above recording apparatus.

5 (a) and 5 (b) are diagrams for explaining the recording qualities of the recording apparatus of the present invention and the conventional recording apparatus, respectively.

FIG. 6 is a diagram showing an example of a conventional serial recording device.

[Explanation of symbols]

1 recording head 2 carriage 3 Paper feed drive roller 5 Paper feed motor 6 paper feed rollers 7 Paper edge sensor 8 recording media 11 Recording element 12 nozzle plate 13 nozzles 31 Drive roller gear 32 Paper feed driven roller

─────────────────────────────────────────────────── ─── Continued front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41J 2/255 B41J 2/045 B41J 2/055 B41J 2/345

Claims (2)

(57) [Claims] 1. A recording device for recording by moving a recording head having a plurality of recording elements arranged in a sub-scanning direction in a main scanning direction and feeding a recording paper by a constant width for recording. The number is n, the distance between the first recording element and the second recording element is p1, the distance between the second recording element and the third recording element is p2, and the (n-1) th recording element and the nth , The average spacing (p1 + p2 + ... + pn-1) / (n-1) between all the recording elements in the sub-scanning direction is predetermined. equal to the constant reference intervals p which are, and recording said recording elements randomly as the upper limit of the distance difference between the SL recording element <br/> child becomes less transport error of the sheet feed mechanism are arranged apparatus. 2. The recording elements are arranged so that at least two recording elements at both ends of all the recording elements of the recording head in the sub-scanning direction are equal to a reference interval p. The recording device according to claim 1.