JPH1120232A - Image-recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrange groups of light-emitting elements at a proper position even when a speed is changed, by arranging the groups of light-emitting elements at positions shifted by a specific distance at the opposite side to a movement direction of a sub scan direction when the groups of light-emitting elements and a recording medium are relatively moved in the sub scan direction thereby recording images. SOLUTION: Heads 31-33 each having a plurality of light-emitting elements are loaded on a carriage 30. While a recording medium held at a drum 20 is rotated in a main scan direction, the carriage 30 is moved in a sub scan direction to record images. At this time, groups of the plurality of light-emitting elements of different recording colors, namely, heads 31-33 are arranged at positions shifted by a distance S=L×A/360+n×p at the opposite side to a movement direction of the sub scan direction wherein the L is a feed amount in the sub scan direction at one rotation in the main scan direction, A is an arrangement angle of the group of light-emitting elements to a reference group of light-emitting elements seen from a center of the drum, (n) is an integer and P is a pitch of dots formed by the light-emitting elements on the image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium and a light emitting element group which are relatively rotated in a main scanning direction with a plurality of light emitting element groups and a recording medium (such as a photosensitive material) disposed on a cylindrical surface. More specifically, the present invention relates to an image recording apparatus that records an image on a recording medium by relatively moving the image recording medium in a sub-scanning direction, and particularly relates to an image recording apparatus that takes into consideration a change in speed in the sub-scanning direction.

[0002]

2. Description of the Related Art A plurality of R, G, and B light emitting element groups and a recording medium disposed on a cylindrical surface are relatively rotated in a main scanning direction, and the recording medium and the light emitting element group are subordinate. 2. Description of the Related Art An image recording apparatus that records an image on a recording medium by relatively moving the recording medium in a scanning direction is known.

In this type of image recording apparatus, exposure is performed spirally on a cylindrical surface by main scanning by rotation of a cylinder on which a recording medium is arranged and sub-scanning by movement of a light emitting element group. In this case, in order to obtain a clear image, a plurality of light emitting element groups need to expose the recording medium at the same point.

The fine adjustment of the alignment of a plurality of light emitting element groups in such an image recording apparatus is described in, for example, JP-A-63-31171 and JP-A-63-3121.
No. 09478.

[0005]

According to the above-described fine adjustment, it is possible to perform exposure alignment between a plurality of light emitting element groups, but the speed of either the main scanning or the sub-scanning is changed. In this case, the exposure of each color does not match.

That is, in the conventional fine adjustment, no consideration is given to a change in the speed of the main scanning or the sub-scanning, and the image quality is deteriorated due to a color shift. When trying to adjust such a problem mechanically, it is difficult to adjust, and the type of spacer increases. Further, if all of them are to be adjusted electrically, an interpolation process or the like is required, and there is a problem that the circuit scale becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and has been made in consideration of the above problem. When recording an image on a recording medium by relatively moving the light emitting element group in the sub-scanning direction, the light emitting element group can be properly positioned even when either the main scanning or the sub scanning speed is changed. It is an object of the present invention to provide an image recording apparatus that can be arranged in a computer.

[0008]

Accordingly, the invention as a means for solving the problem is described below. (1) According to the first aspect of the present invention, while rotating a plurality of light emitting element groups and a recording medium arranged on a cylindrical surface relatively in a main scanning direction, the recording medium and the light emitting element groups are moved in a sub scanning direction. An image recording apparatus for recording an image on a recording medium by relatively moving, S = L × A / 360 + n × P, where L is a feed amount of a sub-scan in one rotation of a main scan, and A is a center of a cylinder. The arrangement angle of the light emitting element group with respect to the light emitting element group as a reference when viewed from the viewpoint, n is an integer, P is the pitch between dots formed by the light emitting elements on the image, and An image recording apparatus, wherein a plurality of different light emitting element groups are arranged at a position shifted by S from a reference light emitting element group on a side opposite to a moving direction in a sub-scanning direction.

In this invention of the image recording apparatus, the shift position of the light emitting element group is determined based on the feed amount L of the sub-scan in one rotation of the main scan, so that even if the speed of the main scan or the sub-scan changes, Exposure consistent with each light emitting element group is performed.

Further, a rough position adjustment for each line in the sub-scanning direction corresponding to n × P is electrically selected by image data, and a deviation in the sub-scanning direction within one line is mechanically determined based on the L. Just do it.

As a result, the recording medium and the light emitting element group are relatively moved in the sub-scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. As a result, when recording an image on a recording medium, the light emitting element group can be arranged at an appropriate position even when the speed of either the main scanning or the sub scanning is changed, and the deterioration of the image quality due to color shift is prevented can do.

(2) According to the second aspect of the present invention, while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction, the recording medium and the light emitting element group are subordinately rotated. An image recording apparatus for recording an image on a recording medium by relatively moving in a scanning direction, wherein S = LAV × A / 360 + n × P, where LAV is a feed amount of a sub-scan in one rotation of a main scan. The average value when the feed amount changes, A is the arrangement angle of the corresponding light emitting element group with respect to the reference light emitting element group when viewed from the center of the cylinder, n is an integer, and P is formed by the light emitting element on the image. When the pitch between dots is different, the plurality of light emitting element groups having different recording colors are arranged on the opposite side of the moving direction in the sub-scanning direction at a position shifted by S from the reference light emitting element group. Image recording apparatus characterized by the above-mentioned. It is.

In the invention of this image recording apparatus, the shift position of the light emitting element group is determined based on the average value LAV of the feed amount of the sub-scan in one rotation of the main scan. However, the same exposure is performed by each light emitting element group.

Further, rough position adjustment for each line in the sub-scanning direction corresponding to n × P is electrically selected by image data, and a deviation in the sub-scanning direction within one line is mechanically determined based on the L. Just do it.

As a result, the recording medium and the light emitting element group are relatively moved in the sub scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. As a result, when recording an image on a recording medium, the light emitting element group can be arranged at an appropriate position even when the speed of either the main scanning or the sub scanning is changed, and the deterioration of the image quality due to color shift is prevented can do.

(3) According to the third aspect of the present invention, while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction, the recording medium and the light emitting element groups are rotated in the sub scanning direction. An image recording apparatus for recording an image on a recording medium by relatively moving in a scanning direction, wherein: S = L × A / 360 + n × P, where L is a feed amount of a sub-scan in one rotation of a main scan, A Is the arrangement angle of the light emitting element group with respect to the light emitting element group as a reference when viewed from the center of the cylinder, n is an integer, and P is the pitch between dots formed by the light emitting elements on the image. Position adjustment means for adjusting the arrangement of the plurality of light emitting element groups having different recording colors on the opposite side of the moving direction in the sub-scanning direction so as to be arranged at a position shifted by S from the reference light emitting element group. An image recording apparatus characterized by the following:

In the invention of this image recording apparatus, the shift position of the light emitting element group is determined based on the feed amount L of the sub-scan in one main scan, and the shift position is adjusted by the position adjusting means. Even if the speed of sub-scanning changes, the same exposure is performed by each light emitting element group.

Further, rough position adjustment for each line in the sub-scanning direction corresponding to n × P is electrically selected by image data, and a deviation in the sub-scanning direction within one line is mechanically determined based on the L. Just do it.

As a result, the recording medium and the light emitting element group are relatively moved in the sub scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. As a result, when recording an image on a recording medium, the light emitting element group can be arranged at an appropriate position even when the speed of either the main scanning or the sub scanning is changed, and the deterioration of the image quality due to color shift is prevented can do.

[0020]

Next, an embodiment of the present invention will be described with reference to the drawings. <Configuration of Image Recording Apparatus> First, the configuration of the image recording apparatus of the present embodiment will be described with reference to FIG. This figure 1
The control unit 10 is a control unit that controls the entire image recording apparatus. In particular, the control unit 10 controls the recording medium while rotating the plurality of light emitting element groups and the recording medium disposed on the cylindrical surface relatively in the main scanning direction. When recording an image on a recording medium by relatively moving the light emitting element group in the sub-scanning direction, the light emitting element group can be properly positioned even when either the main scanning or the sub scanning speed is changed. Is controlled so that

The recording medium 1 such as a photosensitive material is adhered to the drum 20 and rotates at a predetermined speed. The main scanning drive section 21 drives the drum 20 to rotate in the main scanning direction. The carriage 30 constitutes a head holding / driving unit for driving the heads 31 to 33 in a sub-scanning direction while holding the heads 31 to 33 at predetermined positions.

Here, an example is shown in which a first head 31, a second head 32, and a third head 33 are arranged on a carriage 30. Each of the heads 31 to 33 is provided with a plurality of light emitting elements (LED, laser diode, etc.), and each of the light emitting elements is configured to be capable of emitting light modulated independently.

The first head 31 to the third head 33 are provided to form different recording colors on the recording medium 1, and for example,
A head that emits light in R, G, and B to emit C, M, and Y, and a head that emits light in far-infrared, near-infrared, and red to emit light in C, M, and Y, are applicable. In other words, it is a head that outputs light having different wavelengths (including infrared rays, etc.) in order to produce a predetermined recording color. Therefore, “a plurality of light-emitting element groups having different recording colors” in the claims means the heads 31 to 33 configured as described above. In this embodiment, R,
A description will be given by taking a head that emits light in G and B as an example.

As shown in FIG. 2, the first head 3
1 as a reference, A
It is assumed that the second head 32 is arranged at 12 ° and the third head 33 is similarly arranged at A13 °.

The carriage 30 has a guide shaft 3
While being supported by 5 and 36, it is driven by the sub-scanning drive unit 34 to move in the sub-scanning direction. Note that, in FIG. 2, the near side perpendicular to the paper surface, and in FIG. 3, the right side is treated as the sub-scanning direction in which the carriage 30 should move.

The image processing section 40 is image processing means for receiving image data from an external device (such as a computer) and developing the image data into a format for image recording, and includes a frame memory and the like.

The line buffer 50 is timing adjustment means for receiving image data from the image processing unit 40 and outputting the data in accordance with the exposure timing of each head.
Data such as the amount of sub-scanning delay from the data.
The line buffer 50 includes line buffers 51 to 53 so as to correspond to each color of RGB.

The LED driver 60 includes a line buffer 50
Is an electric drive unit that receives data from the CPU and generates a signal for driving a light emitting element (LED) group built in each head, and is configured by LED drivers 61 to 63 so as to correspond to each color of RGB. Have been. Note that, in this embodiment, an example in which an LED is used as a light emitting element group is used. However, when a laser diode is used as a light emitting element group, a driver for a laser diode may be used.

The position adjusting unit 71 receives an instruction from the control unit 10 and arranges a plurality of heads having different recording colors.
As shown in FIG. 3, on the opposite side of the moving direction in the sub-scanning direction,
The position adjusting means 72 and 72 are arranged at positions shifted from the reference head by a predetermined amount (S described later).
Is to adjust.

Here, the position adjusting means 72 and 73 include various kinds of position adjusting means such as a cam controlled by a motor or the like and a combination of an actuator, a piezo element, and a feedback sensor. When it is not necessary to change the value after the adjustment, a spacer or the like may be used.

In this embodiment, the drum 20
The main scanning and the sub-scanning are performed by rotating the carriage 30 and the sub-scanning is performed by way of example. However, as long as the main scanning and the sub-scanning are relatively moved, either side may be moved. .

<Operation> The arrangement of the heads 31 to 33 will now be described. Here, the position of the head 32 and the position of the head 33 will be described with reference to the head 31.

As shown in FIGS. 3 and 4, the head 32 is arranged at a position shifted from the head 31 by S12 in the direction opposite to the sub-scanning direction by the position adjusting means 72. In the same manner, the head 3
Reference numeral 3 is disposed at a position shifted from the head 31 by S13 in the direction opposite to the sub-scanning direction.

Here, as an example of the light-emitting element group, eight LEDs are arranged in one line in each head. However, more LEDs are arranged in one line, or LEDs in a plurality of lines are arranged. It may be arranged.

Here, L is the feed amount of the sub-scan in one rotation of the main scan, and A is the arrangement angle of the light-emitting element group with respect to the light-emitting element group as a reference when viewed from the center of the cylinder. S = L × A / 360.

That is, in the head 32 disposed at A12 ° with respect to the head 31, the position is adjusted by the position adjusting means 72 so as to be arranged at a position shifted by the shift amount S12 obtained as S12 = L × A12 / 360. .

Similarly, in the head 33 arranged at A13 ° with respect to the head 31, the position adjusting means 73 adjusts the head 33 so as to be arranged at a position shifted by the shift amount S13 calculated as S13 = L × A13 / 360. I do.

In this case, as shown in FIG. 5, it is possible to follow a locus where the LEDs of the respective heads coincide with each other on the main scanning line by exposure. Even when the speed of the sub-scanning is changed by changing the sensitivity of the recording medium or the like, by changing the shift amounts S12 and S13 in accordance with the speed of the sub-scanning, each head can be moved on the main scanning line by exposure. The trajectory where the LEDs match can be followed, and no color shift occurs.

Since L is the feed amount of the sub-scan in one rotation of the main scan, when the speed of the main scan is changed in addition to the speed of the sub-scan, the speed of both the main scan and the sub-scan is changed. Even when there is a change, it is possible to arrange each head at a predetermined position so that color shift does not occur.

As a result, the recording medium and the light emitting element group are relatively moved in the sub-scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. This makes it possible to realize an image recording apparatus in which the light emitting element group can be arranged at an appropriate position even when the speed of either the main scanning or the sub scanning is changed when performing image recording on a recording medium.

<Operation> Here, a second operation example regarding the positional relationship between the heads 31 to 33 will be described.

A description will be given with reference to FIG. 6 corresponding to FIG. As shown in FIG. 6, the head 32 is arranged at a position shifted from the head 31 by S12 in the direction opposite to the sub-scanning direction by the position adjusting means 72. Similarly, the head 33 is moved to the head 3 by the position adjusting means 73.
It is arranged at a position shifted from the sub-scanning direction by 1 relative to 1 in the sub-scanning direction.

Here, L is the feed amount of the sub-scan in one rotation of the main scan, A is the arrangement angle of the light emitting element group with respect to the light emitting element group as a reference when viewed from the center of the cylinder, n is an integer, P Is the pitch between dots formed by the light emitting elements on the image, and S = L × A / 360 + n × P.

That is, in the head 32 arranged at A12 ° with respect to the head 31, mechanical adjustment is performed by the position adjusting means 72 so that the head 32 is arranged at a position shifted by the shift amount S12 calculated as S12 = L × A12 / 360. And adjust
n × P is electrically shifted. In the example of FIG. 6, n = 3 because the lines are shifted by three lines.

As a result, assuming that S2 = L × A12 / 360 + 3 × P, fine adjustment in the line is mechanically performed, and rough adjustment for each line is adjusted at electrical timing.

Similarly, in the head 33 arranged at A13 ° with respect to the head 31, S3 = L × A13 / 360 + 6 × P. Rough adjustments are made at electrical timing.

In this case, even when the scanning as shown in FIG. 6 is performed, it is possible to follow the locus where the LEDs of the respective heads coincide on the main scanning line by exposure. When the trajectories are made to coincide with each other in this manner, it is not necessary to actually arrange the LEDs corresponding to each head on the same line in the scanning direction by using the electric adjustment.

Even when the sub-scanning speed is changed by changing the sensitivity of the recording medium, etc.,
By changing the shift amounts S2 and S3, it is possible to follow the trajectory where the LEDs of the respective heads coincide on the main scanning line by exposure, and no color shift occurs.

Since L is the feed amount of the sub-scan in one rotation of the main scan, not only the speed of the sub-scan but also the speed of the main scan is changed. Even when there is a change, it is possible to arrange each head at a predetermined position so that color shift does not occur.

By combining the electrical rough adjustment (adjustment for each main scanning line) and the mechanical fine adjustment (adjustment of less than one line), the speed of the main scanning and the sub-scanning is greatly reduced. It is possible to cope with a case where a significant change occurs, and it is possible to effectively prevent the occurrence of color shift.

As a result, the recording medium and the light emitting element group are relatively moved in the sub-scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. This makes it possible to realize an image recording apparatus in which the light emitting element group can be arranged at an appropriate position even when the speed of either the main scanning or the sub scanning is changed when performing image recording on a recording medium.

The configuration of the line buffer 50 for electrically adjusting the timing as described above is as shown in FIG. FIG. 7 shows the circuit configuration of any one of the line buffers 51 to 53.
In the case of three colors of GB, it is assumed that three equivalent circuits are provided.

The image data from the image processing section 40 is taken into the memory 50b via the controller 50a. At this time, the address according to the number of pixels / line data from the control unit 10 is written into the write address generator 50d.
Is generated, and the image data is written into the memory 50b according to the address.

When recording an image, the read address generator 50e outputs the value (n)
XP), an address suitable for reading out image data corresponding to the LED of each head is generated. In this case, the value of the sub-scanning delay may be changed by changing the initial value of the count value.

Then, the image data read from the memory 50b by such address data is supplied to the LED driver via the controller 50f.
The read address generator 50 shown in FIG.
e includes a sub-scanning position adjustment unit and a sub-scanning counter.
The same operation is possible even if the order is reversed.

Although the memory 50b has a ring-like counter configuration in the example of FIG. 7, the same operation can be performed by using a decoder (look-up table) for sub-scanning position adjustment. It is possible to do.

As described above, when the mechanical adjustment of less than one line is combined with the rough electric adjustment of each line, the shift amount of 0.5 line or more is changed by one line of the electrical adjustment. By replacing the adjustment with an adjustment, the mechanical adjustment is reduced to 0.1.
It can be less than 5 lines. In this case, the control unit 10 may perform an arithmetic process for incorporating a shift amount of 0.5 line or more into the electrical adjustment of one line.

By doing so, the mechanical adjustment range is narrowed, so that the position adjusting means 72, 73 can be made smaller (thinner), and the accuracy can be improved.

As described above, when the electrical adjustment and the mechanical adjustment are combined, if the mechanical adjustment is performed with a spacer or the like, the type and number of required spacers can be reduced. And it can be easily configured.

As described above, when the adjustment is performed by the spacer, the feed amount L of the sub-scan is calculated using the average value LAV of several different Ls, and S = LAV.times.A / 360 + n.times.P. It is also possible to use

When several different L's are relatively close values, a sufficient effect can be obtained even by adjusting the average value LAV.

[0062]

As described in detail above, according to the inventions described in this specification, the following effects can be obtained.

(1) According to the first aspect of the invention, the main scanning 1
Since the shift position of the light emitting element group is determined based on the feed amount L of the sub scanning in the rotation, even if the speed of the main scanning or the sub scanning changes, the same light exposure is performed by each light emitting element group. .

Further, rough position adjustment for each line in the sub-scanning direction may be electrically performed by selecting image data, and a shift within one line in the sub-scanning direction may be mechanically performed based on the L.

As a result, the recording medium and the light emitting element group are relatively moved in the sub scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. As a result, when recording an image on a recording medium, the light emitting element group can be arranged at an appropriate position even when the speed of either the main scanning or the sub scanning is changed, and the deterioration of the image quality due to color shift is prevented can do.

(2) According to the second aspect of the invention, the main scanning 1
Since the shift position of the light emitting element group is determined based on the average value LAV of the feed amount of the sub scanning in the rotation, even if the speed of the main scanning or the sub scanning changes, the same light exposure is performed by each light emitting element group. Become like

The rough position adjustment for each line in the sub-scanning direction corresponding to n × P is electrically selected by image data, and the deviation in the sub-scanning direction within one line is mechanically determined based on the L. Just do it.

As a result, the recording medium and the light emitting element group are relatively moved in the sub scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. As a result, when recording an image on a recording medium, the light emitting element group can be arranged at an appropriate position even when the speed of either the main scanning or the sub scanning is changed, and the deterioration of the image quality due to color shift is prevented can do.

(3) According to the third aspect of the present invention, the main scanning 1
The shift position of the light emitting element group is determined based on the feed amount L of the sub-scan in the rotation, and the shift position is adjusted by the position adjusting means. Therefore, even if the speed of the main scanning or the sub-scan is changed, each light emitting element group is changed. , The matching exposure is performed.

The rough position adjustment for each line in the sub-scanning direction corresponding to n × P is electrically selected by image data, and the deviation in the sub-scanning direction within one line is mechanically determined based on the L. Just do it.

As a result, the recording medium and the light emitting element group are relatively moved in the sub-scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. As a result, when recording an image on a recording medium, the light emitting element group can be arranged at an appropriate position even when the speed of either the main scanning or the sub scanning is changed, and the deterioration of the image quality due to color shift is prevented can do.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of an image recording apparatus used in an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a configuration of a main part of the image recording apparatus used in the embodiment of the present invention.

FIG. 3 is a configuration diagram showing a configuration of a main part of the image recording apparatus used in the embodiment of the present invention.

FIG. 4 is a configuration diagram showing a configuration of a main part of an image recording apparatus used in an embodiment of the present invention and a state of scanning.

FIG. 5 is a schematic diagram schematically showing a scanning state of the image recording apparatus used in the embodiment of the present invention.

FIG. 6 is a configuration diagram showing a configuration of a main part of an image recording apparatus used in an embodiment of the present invention and a state of scanning.

FIG. 7 is a configuration diagram showing a configuration of a main part of the image recording apparatus used in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording medium 10 Control part 20 Drum 21 Main scanning drive part 30 Carriage 31-33 Head 40 Image processing part 50 Line buffer 60 LED driver 71 Position adjustment part 72,72 Position adjustment means

Claims (3)

[Claims] 1. A recording medium and a light emitting element group are relatively moved in a sub-scanning direction while a plurality of light emitting element groups and a recording medium arranged on a cylindrical surface are relatively rotated in a main scanning direction. An image recording apparatus for performing image recording on a recording medium according to claim 1, wherein a plurality of light emitting element groups having different recording colors are arranged on a side opposite to the moving direction in the sub-scanning direction with respect to a reference light emitting element group. An image recording apparatus, wherein the image recording apparatus is disposed at a position shifted only by a distance. S = L × A / 360 + n × P where L is the feed amount of the sub-scan in one rotation of the main scan, and A is the arrangement angle of the light-emitting element group with respect to the reference light-emitting element group when viewed from the center of the cylinder. , N is an integer, and P is the pitch between dots formed by the light emitting elements on the image. 2. A method according to claim 1, wherein the recording medium and the light emitting element group are relatively moved in the sub-scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. An image recording apparatus for performing image recording on a recording medium according to claim 1, wherein a plurality of light emitting element groups having different recording colors are arranged on a side opposite to the moving direction in the sub-scanning direction with respect to a reference light emitting element group. An image recording apparatus, wherein the image recording apparatus is disposed at a position shifted only by a distance. S = LAV × A / 360 + n × P Here, LAV is a feed amount of the sub-scan in one rotation of the main scan.
The average value when the feed amount changes, A is the arrangement angle of the corresponding light emitting element group with respect to the reference light emitting element group when viewed from the center of the cylinder, n is an integer, and P is formed by the light emitting element on the image. Pitch between dots 3. The recording medium and the light emitting element group are relatively moved in the sub-scanning direction while the plurality of light emitting element groups and the recording medium arranged on the cylindrical surface are relatively rotated in the main scanning direction. An image recording apparatus for performing image recording on a recording medium according to claim 1, wherein a plurality of light emitting element groups having different recording colors are arranged on a side opposite to the moving direction in the sub-scanning direction with respect to a reference light emitting element group. An image recording apparatus comprising: a position adjusting unit that adjusts the position of the image recording apparatus so as to be arranged at a position shifted only by the position. S = L × A / 360 + n × P where L is the feed amount of the sub-scan in one rotation of the main scan, and A is the arrangement angle of the light-emitting element group with respect to the reference light-emitting element group when viewed from the center of the cylinder. , N is an integer, and P is the pitch between dots formed by the light emitting elements on the image.