JP2002273922A - Head for forming image and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head for forming an image and an image forming apparatus by which image forming time is prevented from being prolonged and in addition, an image forming in which boundary parts of the image prepared by a plurality of light sources are unattractive can be performed when the image forming is performed on a heat-sensitive recording medium held by a recording medium holding drum. SOLUTION: A plurality of the light sources 4 of a plurality of sets of the light sources for forming the head 3 for forming the image are not uniformly arranged but the sets of the light sources are respectively combined in such a way that the light sources standing in a line at intervals being at most an interval of a pixel with an image resolution (a high density arrangement) are arranged on each of the boundaries of the sets of a plurality of light sources. By performing the image forming at intervals being at most the interval of the pixel on at least each of the boundary parts of the sets of the light sources, it is possible to prevent the image forming time from being prolonged and to perform the image forming in which the boundary parts are unattractive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming head and an image forming apparatus using the image forming head.
More specifically, the plurality of light sources of the plurality of light source sets forming the image forming head are not all arranged at equal intervals, and image forming is performed by combining the respective light source sets so that the light sources arranged at high density are partially arranged. The present invention relates to an image forming head and an image forming apparatus using the image forming head.

[0002]

2. Description of the Related Art As an image forming head of a recording medium on which an image is formed by heating, the following is known as a conventional example. Japanese Patent Application Laid-Open No. 7-23195 (Method and Apparatus for Correcting and Adjusting Digital Image Output) discloses a method for forming an image using a head in which a large number of light sources are linearly arranged. 2 shows a method relating to a data correction method in a case where there is a position shift in irradiation light from the camera. However, since the head used has a large number of light sources arranged at equal intervals over the entire image width, if the irradiation position intervals from each light source to the recording medium are not equal intervals, the head moves in the direction perpendicular to the drum rotation direction. Since it is necessary to make the moving amount of the image forming head shorter than the interval of the image resolution and form the image between the light sources, it is necessary to rotate the drum more, and as a result, the image forming time becomes longer. Problem.

[0003] The invention of Japanese Patent No. 02648081 (laser discharge imaging method and apparatus) describes a head in which a plurality of light sources are obliquely shifted by minute amounts at equal intervals, in addition to an image forming head having the same configuration as described above. ing. The former involves the same problem as described above, and the latter is considered to be the case where the irradiation intervals from a plurality of light sources are arranged at one pixel interval or the case where they are arranged at a plurality of pixel intervals. In the case of a head in which light sources are arranged at one pixel intervals, it is difficult to imagine arranging the number of light sources capable of irradiating the entire image area because it is disadvantageous in terms of cost and size of the head. Shorter than In this case, it is necessary to move the head by the irradiation width for each rotation of the drum, so that high-speed movement is required, and very high movement accuracy is required in accordance with the density of the formed image. Therefore, not only the head but also the entire apparatus requires extremely high mechanical accuracy, and there is a problem that the apparatus cost is significantly increased. In addition, if the number of light sources in the head is increased, the printing time can be shortened. However, if the number of light sources is increased, the irradiation width of the head is increased. Is required to be more robust, and the cost of the apparatus is further increased. Therefore, in order to reduce the cost of the apparatus, it is necessary to reduce the number of light sources or the rotational speed of the drum, and there is a drawback that the image formation time is eventually increased.

On the other hand, in the case of a head in which light sources are arranged at a plurality of pixel intervals, a head in which light sources are arranged at equal intervals over the entire image width and a head in which a plurality of light sources are arranged in a width shorter than the entire image width are considered. However, the former has the same problem as the head described in Japanese Patent Application Laid-Open No. Hei 7-23195, and the latter has the problem that the head movement control and the data transfer method become more complicated in addition to the same problem as the former. Will occur.

The invention of US Pat. No. 5,182,990 also describes a head in which a plurality of light sources are obliquely arranged at small intervals at equal intervals, similarly to the head of the invention of Japanese Patent No. 02648081. I have JP 5
In the invention of JP-A-238024 (high-resolution thermal dye transfer apparatus), image formation is performed by setting a head in which a plurality of light sources are linearly arranged at an angle of 90 ° or less with respect to a direction perpendicular to the rotation direction of the drum. Are described. However, the head used in the present invention has a problem in that since the irradiation target is a curved surface, the focal length of each light source in the head is different, and the spot shape formed on the recording medium varies. In addition, there is a description that a curvature corresponding to the curved surface of the drum is given to the end face of the head. However, such a head is difficult to manufacture, and the mounting and adjustment method of the light source becomes very complicated. IS &T's Tenth International Congress on A
dvances in Non-Impact Printing Technologies (1994)
P.337-339), “High Power Multi-Channel Writ
ing Heads "describes five types of head configurations with multiple light sources. However, the configurations are one pixel or multiple pixel-spaced and equally spaced, diagonally or zigzag or parallel to the drum axis. The configuration is such that the light sources are arranged in the directions, and all have the same problems as described above.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention does not arrange all of the plurality of light sources at equal intervals. Combine the light source sets so that the light sources arranged at intervals equal to or less than the pixel interval of the image resolution (hereinafter referred to as high-density arrangement are arranged at intervals equal to or less than the pixel interval of the image resolution) In addition, at least each boundary portion between the light source sets forms an image at an interval equal to or less than the pixel interval, thereby preventing the image forming time from being extended, and further enabling image formation in which the boundary portion is inconspicuous. And an image forming apparatus are proposed. That is, the light source set is a light source set including a single light source or a plurality of light sources arranged at a high density with respect to a plurality of light sources arranged adjacently at equal intervals, or a plurality of light sources arranged adjacent at equal intervals. It means a light source set made up of light sources, a light source set made up of a plurality of light sources arranged at high density, or a light source set made up of a single light source.

According to the first aspect of the present invention, it is possible to reduce the image forming time in comparison with the conventional method of making the boundary area of each image formed by a plurality of light sources or light source sets inconspicuous.
Further, it is another object of the present invention to provide an image forming head in which an apparatus control system can be simplified.

A second object of the present invention is to provide an image forming apparatus which forms a high-quality image in a short time by a control system having a simple configuration using the image forming head of the first embodiment. .

According to a third aspect of the present invention, the head structure is simpler than the image forming head of the first aspect, and
It is an object of the present invention to provide an image forming head in which a data transfer system can be simplified.

A fourth object of the present invention is to provide an image forming apparatus for forming a high-quality image in a data transfer system having a simple structure using the image forming head of the third embodiment.

According to a fifth aspect of the present invention, in comparison with the image forming heads of the first and third aspects, the head configuration and head fabrication can be simplified, and the transfer data and the data transfer system can be simplified. It is an object to provide a forming head.

According to a sixth aspect of the present invention, a high-quality image is formed on the image forming head of the second and fourth aspects by using a data transfer system having a simpler configuration using the image forming head of the fifth aspect. It is an object of the present invention to provide an image forming apparatus for performing the above.

According to a seventh aspect of the present invention, in the image forming head according to the first, third, and fifth aspects, it is possible to simplify the head configuration and head manufacturing and to reduce the cost of the head. It is an object to provide a head for use.

According to an eighth aspect of the present invention, there is provided an image forming apparatus in which the cost can be further reduced with respect to the image forming apparatuses of the second, fourth and sixth aspects by using the image forming head of the seventh aspect. The purpose is to:

The invention of claim 9 is the invention of claims 2, 4, 6, 8
An image forming apparatus capable of making a boundary region of an image formed by each light source or a set of light sources inconspicuous even when the arrangement of a plurality of light sources or a set of light sources is displaced with respect to the image forming apparatus. The purpose is to provide.

A further object of the present invention is to provide an image forming apparatus in which a boundary region of an image formed by each light source or a set of light sources is less noticeable than the image forming apparatus of the ninth aspect.

The invention of claim 11 is the invention of claims 2, 4, 6,
In the case where the arrangement of the plurality of light sources or the light source sets is shifted with respect to the image forming apparatuses of 8 to 10, the boundary region of the image formed by each light source or the light source set can be made less noticeable. It is an object to provide an image forming apparatus.

According to a twelfth aspect of the present invention,
In the case where the arrangement of the plurality of light sources or the light source sets is shifted with respect to the image forming apparatuses of Nos. 8 to 11, it is possible to make the boundary region of the image formed by each light source or the light source set less noticeable. It is an object to provide an image forming apparatus.

According to a thirteenth aspect of the present invention,
An object of the present invention is to provide an image forming apparatus capable of reducing the variation in the position of irradiation light on a recording medium caused by mechanical vibrations or mechanical errors of device parts for the image forming apparatuses of Nos. 8 to 12.

The invention of claim 14 is the invention of claims 2, 4, 6,
An object of the present invention is to apply the image forming apparatuses of Nos. 8 to 13 to image formation on a printing plate material.

An object of the present invention is to provide an image forming apparatus capable of forming an image with a lower energy amount than the image forming apparatus of the present invention.

An object of the present invention is to provide an image forming apparatus in which handling is improved since liquid does not need to be used at the time of forming an image.

A further object of the present invention is to provide an image forming apparatus capable of forming a large number of images on recording paper at high speed with respect to the image forming apparatuses of the present invention. .

An object of the present invention is to provide an image forming apparatus capable of forming a multi-color image by using the techniques of claims 1 to 17.

[0025]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art, and the first technical means is a recording medium which is held by a recording medium holding drum and is formed by heating to form an image. In an image forming head having a plurality of light source sets each including one or more light sources arranged to irradiate a medium, at least one of at least one light source set of the light source sets having the plurality of light sources A plurality of light sources at the end are arranged at a high density at an interval equal to or less than an image resolution pixel interval in a direction perpendicular to the recording medium holding drum rotation direction.

The second technical means is an image forming apparatus using the image forming head of the first technical means.

A third technical means is the image forming head according to the first technical means, wherein the target light source of the adjacent light source set comprising a plurality of light sources adjacent to the target light source set having the plurality of light sources arranged at high density. The plurality of light sources at the end closer to the set of high-density light sources are not densely arranged.

The fourth technical means is an image forming apparatus using the image forming head of the third technical means.

A fifth technical means is the image forming head according to the first technical means, wherein all light source sets having a plurality of light sources have light sources densely arranged, and the high density arrangement in each light source set is provided. The light source positions are all unified on the left side or right side from the image forming head toward the recording medium holding drum.

The sixth technical means is an image forming apparatus using the image forming head of the fifth technical means.

According to a seventh technical means, in the image forming head according to the first, third, or fifth technical means, the light sources at both ends of the image forming head are not arranged at high density.

The eighth technical means is an image forming apparatus using the image forming head of the seventh technical means.

According to a ninth technical means, in the image forming apparatus according to the second, fourth, sixth, or eighth technical means, the plurality of light sources arranged at high density are arranged such that an end light source among the plurality of light sources is an image. An image is formed such that a region to be formed and a region where an image is formed by a light source set adjacent to the end side light source at least partially overlap.

A tenth technical means is the image forming apparatus according to the ninth technical means, wherein an amount of overlap of images formed by adjacent light source sets is less than one pixel width of the image resolution.

The eleventh technical means includes the second, fourth, sixth, eighth to eighth technical means.
The image forming apparatus according to the ten technical means is characterized in that at least two lines at the boundary between adjacent light source sets form an image with data having the same contents.

The twelfth technical means includes the second, fourth, sixth, eighth through
In the image forming apparatus according to the eleventh technical means, the edge light sources arranged at high density based on the irradiation position shift state of the laser light emitted from each light source set on the recording medium in the direction perpendicular to the rotation direction of the recording medium holding drum. It is characterized in that the contents of the data to be transferred to are determined.

The thirteenth technical means includes the second, fourth, sixth, eighth through
An image forming apparatus according to a twelfth technical means, further comprising a drum position detecting means for detecting a position of the recording medium holding drum, and determining an image data transfer timing based on information of the drum position detecting means. And

The fourteenth technical means includes the second, fourth, sixth, eighth through
The image forming apparatus according to the thirteenth technical means is characterized in that the recording medium has a property that ink adhesion characteristics are different between a heated area and a non-heated area.

According to a fifteenth technical means, in the image forming apparatus of the fourteenth technical means, the receding contact angle decreases when the recording medium is brought into contact with a liquid in a heated state (a lyophilic state),
Further, it is characterized by having surface characteristics in which the receding contact angle increases when heated in a non-contact state with a liquid (liquid-repellent state).

According to a sixteenth technical means, in the image forming apparatus according to the fifteenth technical means, an image is formed by heating a non-image area.

A seventeenth technical means is the image forming apparatus according to the fourteenth to sixteenth technical means, further comprising a developing unit for applying ink to an image area of the recording medium, and receiving an ink image from the recording medium onto recording paper. An intermediate transfer member for transferring the ink image and an impression cylinder are provided.

The eighteenth technical means includes the second, fourth, sixth, eighth through
The thirteenth technical means of the image forming apparatus further comprises
A recording medium in the image forming apparatus according to any one of the technical means,
The multi-color image forming apparatus has a plurality of recording medium holding units and a plurality of developing units.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the embodiments shown in the drawings. (Description of the First Embodiment) The present invention relates to an image forming head 3 having a plurality of laser light sources 4 as shown in the example of FIG. Proposed image forming head 3
Is composed of a plurality of light source sets 4a. There are mainly the following four types of light source sets. That is, the first is a light source set composed of a single light source or a plurality of light sources arranged at a high density with respect to a plurality of light sources arranged adjacent at equal intervals, and the second is a plurality of light sources arranged adjacent at equal intervals. A third light source set includes a plurality of light sources arranged at high density, and a fourth light source set includes a single light source. However, configurations other than the above four light source sets can be used. The arrangement of the light source sets 4a needs to satisfy the following conditions. That is, it is necessary to combine the light source sets such that the light sources arranged at intervals equal to or less than the pixel interval of the image resolution are arranged at the boundary between the light source sets. The light source intervals in each light source set may be all the same or may be plural as shown in FIG.
In the drawing, there are an interval of one pixel or more such as d ₁ and a high density interval such as d ₂ which indicates an interval of one pixel or less of the image resolution.

The interval of one pixel or more is desirably one pixel interval of the image resolution from the configuration of the movement control system of the image forming head. In the case where the distance is larger than one pixel interval, it is necessary to be at least an integral multiple of one pixel interval.
The light sources arranged at high-density intervals always exist in a plurality of adjacent light source groups, and the optimal interval varies depending on the content of data to be written, but is preferably about half a pixel. However, the light sources may be arranged at a plurality of different intervals at a high density interval. That is, for example, other than the half pixel interval,
The light sources may be arranged at a plurality of high-density intervals such as a / 4 pixel interval and a 1/8 pixel interval. The interval between the light source sets 4a needs to be at least larger than the width of the light source sets. Also,
It is desirable that the intervals be the same in terms of device control. The light source 4 to be used may be any material as long as the laser light source is desirable. However, an inexpensive and small semiconductor laser is desirable. In the case of irradiation using an optical fiber cable or the like, the light emitting portion of the optical cable is regarded as a light source.

(Explanation of the Invention of Claim 2) The present invention relates to FIG.
The present invention relates to an apparatus for forming an image by irradiating a recording medium 1 mounted on a recording medium holding drum 2 with light by using the image forming head according to the first aspect. The target recording medium 1 may be any material as long as an image is formed by heating by light irradiation.
Note that the image formed on the recording medium 1 is not limited to a visible image, and the physical properties and molecular structure of the surface are changed by heating.
If the state can be detected by any method, it is assumed that the image has been formed. The recording medium holding drum 2 for holding the recording medium is preferably made of a metal because the eccentricity is preferably as small as possible, but may be a resin or a sintered product if the processing accuracy is good. However, the unevenness of the surface needs to be smooth, and it is desirable that the surface is a mirror surface.

Image formation on the recording medium 1 is performed such that writing is performed at high density intervals at least at each boundary between the light source sets. As an example, when an image is formed by the apparatus configuration of FIG. 2 using the image forming head 3 shown in FIG. 1A, if the moving direction of the head during writing is rightward, the recording medium holding at the start of writing is performed. The first rotation of the drum drives the three light sources on the left side of the set of light sources, the second and subsequent rotations drives the two central light sources, and finally the one rotation after writing drives the three right light sources. In this case, the image to be written by the leftmost light source in the first rotation may be any image as long as the image does not have a noticeable boundary, but the image generated by the second light source from the leftmost and the light source set adjacent to the left It is desirable that the correction data be capable of filling in the space between the image and the image generated by the right end light source.

In this way, an image of a half pixel is formed,
By increasing the image width between each light source set, the image formation of the last line can be formed at the same time as the true last line from the image data and the image for filling between the light sources,
Image formation can be performed in a short time. Further, since the image formation at the boundary of each light source set can be performed by the light sources arranged at high density intervals at the end of the light source set, it is not necessary to overuse the light sources at the end of the light sources arranged at an interval of one pixel or more, It is also possible to extend the life of the light source. In addition, when the arrangement of each light source set is shifted in the direction perpendicular to the rotation direction of the drum, a gap is formed at the boundary of the image by each light source set, resulting in a low quality image. However, by arranging a large number of light sources at high-density intervals, it is possible to obtain an image in which a boundary portion is inconspicuous. However, disposing a large number of light sources at high-density intervals has disadvantages because the head shape becomes large and the number of light sources used increases. Therefore, it is necessary to determine the shape in consideration of the required shape, the device cost, and the machine accuracy. In the example of the image forming apparatus shown in FIG. 2, by using the stepping motor 5 as a motor for driving the recording medium holding drum 2, the pixel pitch variation in the circumferential direction of the recording medium holding drum without providing a special control mechanism. Can be kept small.

(Explanation of the invention of claim 3) The present invention has the same basic structure as that of claim 1, except that only one light source set is provided at the boundary of each light source set 4a. That is, there is a light source arranged at a high density. Therefore, as an example, as shown in FIGS. 3A and 3B, a configuration in which light source groups having light sources arranged at high density at both ends and light source groups having no light sources arranged at high density are alternately arranged. Is mentioned. In particular,
In the case of a high-precision image forming head in which one line of a high-density image formed between each light source set is sufficient, the present head may require a smaller number of light sources.

(Explanation of Claim 4) The present invention relates to FIG.
The present invention relates to an apparatus for forming an image by irradiating a recording medium mounted on a recording medium holding drum 2 with light using the image forming head according to the third aspect. The light source used, the recording medium holding drum, and the like are the same as those in the second aspect. The method of driving the head is basically the same, except that the boundary of each light source set is such that only one light source set has a high-density light source. Therefore, when a light source set without a high-density light source is assembled in a manner shifted in the direction perpendicular to the rotation of the drum, correction is performed by a high-density light source in an adjacent light source set.

(Explanation of the invention of claim 5) In the present invention, there are light sources arranged in high density in all the light source sets, and the light source positions in the high density arrangement in each light source set are determined from the image forming head to the recording medium. The present invention relates to an image forming head which is all unified on the left side or the right side of the holding drum, and it is more preferable that all light source sets have the same configuration. The reason is that the same control system and components can be used for all of the data transfer control and head assembly / adjustment, so that development costs and production costs can be reduced. The configuration of the image forming head is shown in FIGS.
As shown in (C), there is one spacing arrangement having a width of one pixel or more and a plurality of high-density arrangements, a light source set including a plurality of high-density arrangement light sources, or a plurality of one-pixel arrangements. There are cases where there is an arrangement with the above intervals and one high-density arrangement. It is desirable that the intervals between the light source sets be equal.

(Explanation of Claim 6) The present invention relates to FIG.
The present invention relates to an apparatus for forming an image by irradiating a recording medium mounted on a recording medium holding drum with light using the image forming head according to the fifth aspect.
Further, a light source and a recording medium holding drum to be used are described in claim 2.
Is the same as The method of driving the heads is basically the same, but differs in that all light source sets can be driven using the same data transfer control system. Therefore, when the data transfer control is divided for each light source set, 1
Only by constructing a control system for one light source set, data transfer to all light source sets becomes possible, so that development efficiency is extremely excellent.

(Explanation of the invention of claim 7) According to the present invention, as compared with the head of claims 1, 3, and 5, an image forming head in which light sources arranged at high density at both ends of the head are not provided. It is about. Since the light sources at both ends of the head form the ends of the image, there is no adjacent light source set. Therefore, there is no need to correct the boundary with the adjacent light source set,
The need for a light source arranged at high density is low, and the absence of the light source as shown in FIG. 7 can reduce the cost required for the light source. However, as described in the sixth aspect of the invention, when there are a plurality of light source sets having different configurations, the control system becomes complicated and the cost increases. Therefore, it is advisable to compare the cost of the light source used and the cost required for the control system and the like to determine which configuration to use.

(Explanation of the Invention of Claim 8) According to the present invention, an image is formed by irradiating a recording medium mounted on a recording medium holding drum with light using the image forming head of the invention. It concerns the device. The light source and the recording medium holding drum to be used are the same as those in the second aspect. When forming an image using the head, care must be taken only when driving the high-density light sources in each light source set. In particular, when the same control system is used for all the light source sets, open the data output port for the light source removed from the head, and in the image data development unit, consider the light source removed at the head end and use the dummy data. It is necessary to make small changes such as inserting data transfer.

(Explanation of the invention of claim 9) The present invention is to make the image break at the boundary part inconspicuous by partially overlapping the mutual images generated by the adjacent light source sets. As shown in FIG. 4B, even when the image is formed by a method in which the images from the two light source sets are in contact with each other and are written at a fine pitch, the image discontinuity at the boundary can be made inconspicuous. However, if this method is used, if the arrangement of the light source sets is displaced in the direction perpendicular to the rotation direction of the drum, a gap will be formed at the boundary of the image by each light source set. It is not practical because very high precision is required for the above-mentioned methods. On the other hand, as shown in FIG. 4A, by forming images so that the image areas formed by the adjacent light source sets overlap to some extent, the dimensions, assembling, and adjustment of the mechanical parts of the image forming head are adjusted. Since it is possible to prevent a gap from being formed at the boundary of the image by each light source set even if there is a certain amount of error in the work, etc., the workability is remarkably improved, and the apparatus cost can be reduced. It becomes possible.

(Explanation of the Tenth Invention) The present invention is different from the ninth invention in that the overlapping area of the mutual images generated by the adjacent light source sets is less than one pixel width. FIG. 5 shows an image forming example of the N-th light source set and the (N + 1) -th light source set. The image line generated by the light sources arranged at high density as shown in FIG. By writing so that the line at the end of the image formed by the method overlaps less than one pixel width, noise is less likely to enter the boundary between the light source sets, and a high-quality image in which the boundary is smooth and the joint is hard to see is formed. It is possible to obtain.

(Explanation of the invention of claim 11) According to the present invention, according to claims 2, 4, 6, 8 to 10, at least two lines at the boundary between adjacent light source sets have the same contents. The method relates to a method of forming an image, for example,
By making two lines of image data generated by adjacent light source sets having an overlap of less than one pixel width as shown in FIG. 5 the same image, the boundaries between the light source sets can be made less noticeable. Becomes In the case of a light source set having light sources densely arranged on both sides as shown in FIGS. 1 and 3, when the moving direction of the image forming head during writing is rightward from the head toward the recording medium holding drum, The data written by the left end light source of the target light source set in the first rotation is
The right end of the light source set on the left side is the same as the image data to be written last, and the data written by the right end light source of the target light source set in the last rotation is the same as the image data written on the left end of the right side light source set first. By using the data of
It is possible to form an image in which the boundaries between the light source sets are inconspicuous.

It is not necessary to drive the high-density light source in areas other than the first and last image formation areas. However, FIG.
In the case where the entire light source set is composed of two high-density light sources as shown in (B), or in the case where four or more even-number high-density light sources are not shown, two adjacent light sources are used. May be used as one set to form the same image. In this case, it is preferable to adjust the amount of irradiation energy or to adjust the shape of the irradiation spot as necessary so as not to cause excessive heating. In addition, when such writing is performed, if the number of light sources in the light source set is an odd number, the light source at the end on the image head moving direction side writes only the last line, and the light source on the opposite side to the image head moving direction is written. For the light source at the end, it is preferable to use a method of writing only the first line.

(Explanation of the invention of claim 12) The present invention is directed to the invention according to claims 2, 4, 6, 8 to 11 in the direction perpendicular to the drum rotation direction on the recording medium of the laser light emitted from each light source set. The present invention relates to a method for determining the contents of data to be transferred to an edge light source arranged at high density based on the irradiation position shift state, and an image forming apparatus using the method. FIG.
FIG. 8A shows an image forming example of the N-th light source set and the (N + 1) -th light source set, and FIG.
FIG. 8B shows a state where the image of the first light source set is at a desired position, and FIG. 8B shows a state in which the image of the (N + 1) th light source set is separated from the Nth light source set. FIG. 8C shows a state in which the image of the (N + 1) th light source set is shifted in the direction approaching the Nth light source set.

In the case as shown in FIG. 8A, the image data used by the high-density light source at the right end of the N-th light source set when forming the image of the last line is that the light source adjacent to the same light source set is the last line. Or the image data formed by the (N + 1) th left end light source in the first line. In the case as shown in FIG. 8B, the image data used by the high-density light source on the right end of the N-th light source set when forming an image on the last line is formed by a light source adjacent to the same light source set on the last line. It is desirable to form the same image as the image data. In the case as shown in FIG. 8C, the image data used by the high-density light source at the right end of the N-th light source set when forming an image on the last line is the image data formed by the (N + 1) -th left-end light source on the first line. It is desirable to form the same image as. 8 (B) and 8 (C) show states in which the N-th and (N + 1) -th light source sets are misaligned. In such a case, to correct the boundary between the two light source sets, As described in claim 11, it is preferable to form and print a plurality of lines at the boundary with the same image data. However, it is desirable that the image width of two lines formed by the same image data be as narrow as possible because the boundaries are not conspicuous and the image is not disturbed. Therefore, in order to determine the image forming method of the boundary portion, each light source, and, it is necessary to examine the position information of the image formed by the light source set, since the method is different even when visible or otherwise, An appropriate method is selected and executed according to the recording medium to be used.

(Description of the Invention of Claim 13) According to the present invention, a means for detecting the position of a recording medium holding drum (hereinafter, referred to as a drum position detecting means) is provided in accordance with Claims 2, 4, 6, and 8 to 12. And an image forming apparatus which determines image data transfer timing based on information of a drum position detecting means. FIG. 9 is a diagram illustrating an image forming apparatus according to a thirteenth embodiment, and FIG. 10 is a block diagram illustrating a transfer system of image data supplied to a light source. Specifically, drum rotation position detecting means 6 for detecting the rotation position of the recording medium holding drum, such as an encoder, is arranged on the axis of the recording medium holding drum 2 for holding the recording medium 1, and the information is also stored. Then, the image data transfer control section 7 changes the transfer timing of the image data.

In the example of FIG. 10, the image data transfer control unit 7
Are a plurality of image data transfer control units 7 ₁ , 7 ₂ ,
..., 7 _n has an image data transfer clock generator 8, respectively, the data receiving unit 9, the data distribution unit 10, the delay generator 11 is formed from a light source driving signal output unit 12, sequentially the image data in each unit While transmitting a request signal and receiving image data in synchronization with the request signal, a plurality of light sources are synchronized in synchronization with an input image transfer clock or an image data transfer clock obtained from a clock signal which is a source of the image transfer clock. Has a function of distributing and transferring image data. However, since the data transfer to each light source 4 is performed at the same timing by the image transfer clock except for the delay time set for each light source, the distribution of the image data to each light source is performed by the image data transfer clock. It is necessary to use a clock having a frequency sufficiently higher than that. The number of light sources controlled by the image data transfer control units 7 ₁ , 7 ₂ ,..., 7 _n (i, j, k values in FIG. 10) may be different or the same, respectively. It is desirable that all the image data transfer control units have the same specifications in terms of development efficiency and manufacturing cost.

A method for controlling the data transfer timing based on the signal from the drum position detecting means 6 includes, for example,
By synchronizing the phase of the image data transfer clock with the output signal from the drum position detecting means by PLL control, or by resetting the image data transfer clock based on the output signal of the drum position detecting means, A method of synchronizing the phase of the output signal from the drum position detecting means is used. By changing the image data transfer timing for each light source in this manner, it is possible to irradiate an optimal position on the recording medium with light, and it is possible to obtain a high-quality image with little pixel variation.

(Explanation of Claim 14) FIG. 11 (A)
11A shows a recording medium 1 having a property that ink adheres to the heating area 1a, and FIG. 11B shows a recording medium 1 having a property that ink adheres to the non-heating area 1b. These can be used as plate materials for direct printing or offset printing. For example, a light absorbing layer is provided on the surface of a material such as aluminum or PET resin, which has excellent ink adhesion, such as metal, resin, or paper. An ink-repellent material layer such as a silicone resin is formed thereon, and the image area is heated so that the ink-repellent material in the heated area is easily removed. By removing the material, a plate can be made in which the ink adheres to the heated area. In addition, a light absorbing layer is provided on the ink repellent material, a material layer having excellent ink adhesion is formed thereon, and the non-image area is heated to remove the ink adhering material. Can be produced. Since a printing plate requires high precision, it is very important to correct and control the writing position.

(Explanation of the Invention of Claim 15) FIG. 12 is a view for explaining a recording medium used by the image forming apparatus of claim 15. FIG. 12A shows an example in which the initial state of the recording medium 1 is set to an ink-repellent state on the entire surface, the liquid 13 is brought into contact with the surface of the recording medium, and the image area is heated to form an image.
FIG. 12B shows the result of developing the ink by attaching the ink to the heating area 1 a of the recording medium 1. In the present recording medium, the receding contact angle is reduced when the recording medium is brought into contact with the liquid (lyophilic state), and the receding contact angle is increased when the recording medium is heated without being contacted with the liquid (lyophobic state). It has surface characteristics and heats the image area in a state where the surface is in contact with a member selected from liquid, vapor, and / or solid, or immediately after heating the surface of the recording medium according to the image information By contacting with a member selected from liquid, vapor, and / or solid, the receding contact angle of the recording medium surface heating portion is reduced to form an image, and is used as a plate for offset printing. This recording medium has a structure in which a light-absorbing layer is provided on the surface of a substrate such as a resin, a metal, and paper, and a recording material layer having the above characteristics is formed thereon, or a recording material layer containing a light-absorbing material is formed on the substrate. The formed structure is used.
This recording medium may not be able to see the image on the surface when heated by laser light irradiation of appropriate energy, so the irradiation position of the light source may be measured using the development result with ink,
Alternatively, it is desirable to use a CCD sensor.

(Explanation of Claim 16) FIG. 13 is a diagram for explaining the present invention. In the present recording medium, the receding contact angle decreases when the recording medium is brought into contact with a liquid in a heated state, similarly to the recording medium used in the image forming apparatus according to claim 15, (lyophilic state),
In addition, a member selected from liquid, vapor, and / or solid has a surface characteristic in which a receding contact angle increases when heated in a non-contact state with a liquid (liquid-repellent state), as shown in FIG. Heating in a state where the recording medium is in contact with the liquid, vapor, and / or immediately after heating the surface of the recording medium.
After the receding contact angle of the surface of the recording medium is reduced by contact with a member selected from solids, only the non-image area of the recording medium is selected in the absence of the contact member as shown in FIG. In this case, the image is formed by heating the film, and the image is developed with ink as shown in FIG. Since the present image forming method is a method for writing a non-image portion, it is necessary to irradiate the non-image region without omission. Therefore, it is very important to correct the writing position deviation.

(Explanation of Claim 17) FIGS. 14 to 16
17 is a diagram illustrating an example of an image forming apparatus according to claim 17. FIG. 14A shows an example of an apparatus for forming an image on a belt-shaped recording medium and attaching ink to the image area to transfer an ink image to recording paper. FIG. FIG. 16 shows an example of an offset printing press having a configuration in which a recording medium is held on a recording medium holding drum while a plate image is formed. FIG. 16 shows a configuration in which a recording medium roll is held inside a plate cylinder, and image formation is performed after feeding one plate. 1 shows an example of an offset printing press. This device can perform plate making and printing inside the device. Although it is conceivable to sacrifice the robustness of the apparatus in order to reduce the apparatus cost, in such a case, it is particularly important to control the image formation by the rotation position detecting means of the recording drum such as an encoder.

(Explanation of Claim 18) FIGS.
FIG. 17 is a diagram illustrating an example of an image forming apparatus according to claim 18. FIG. 17 shows an example of an offset printing press having one impression cylinder, and FIG. 18 shows an example of an offset printing press having two impression cylinders. In the case of a multicolor printing machine, since a plurality of recording media are used, it is necessary to adjust not only the image head position for each color individually but also the image writing position so that the image position of each color matches. In the correction method, the method of matching the second color and the subsequent colors based on the image on the recording medium of the first color does not require adjustment for all colors, so that the adjustment time can be shortened.

Hereinafter, embodiments of the present invention will be described. The common conditions for each embodiment are as follows. << Light source >> (1) 150 mW output, 830 nm wavelength semiconductor laser (DL-8032-001: Sanyo Tottori Electric Co., Ltd.) (2) 60 mW output, 780 nm wavelength semiconductor laser (LNC707PS: Matsushita Electronics) Spot shape: φ20 μm << Recording medium holding drum diameter >> φ17.854 mm

Example 1 (Claims 1 and 2) Recording medium (1) CTC film (having a light absorbing layer containing phthalocyanine dye) (2) Hot-melt ink ribbon (black: containing carbon black) + Recording paper (plain paper, synthetic paper) (3) Thermal sublimation type ink ribbon (black: 6 as light absorbing layer)
μm thick carbon black) + recording paper (PET film, synthetic paper) ● Image forming head ・ Configuration: Fig. 1 (A) ・ Light source: the above light source (1) ・ Number of light sources: 20 ・ Number of light source sets: 5・ Light source arrangement: <interval of one pixel or more> 20 μm, <high-density interval> 10 μm

The above-described head is used in an apparatus having the structure shown in FIG. 2, and each recording medium is mounted on a recording medium holding drum as shown in FIG.
As a result of forming an image at 70 dpi, it was confirmed that a high-quality image in which the boundaries of the images by each light source set were not noticeable could be formed on any of the recording media.

Example 2 (Claims 3 and 4) ● Image forming head ◆ Head 1 ・ Structure: FIG. 3 (A) ・ Light source: The above light source (1) ・ Number of light sources: 18 ・ Number of light source sets: 6・ Light source arrangement: <interval of one pixel or more> 20 μm, <high-density interval> 10 μm ◆ Head 2 ・ Configuration: FIG. 3 (B) ・ Light source: the above light sources (1) ・ Number of light sources: 18 ・ Number of light source sets: 12・ Light source arrangement: <High-density spacing> 10 μm

The above two types of heads are used in an apparatus having the structure shown in FIG. 2, and each recording medium shown in Example 1 is mounted on a recording medium holding drum as shown in FIG. 2B, and the drum is rotated at a drum rotation speed of 67 rpm. As a result of forming an image at 1270 dpi,
It was confirmed that a high-quality image in which the boundaries of the images by each light source set were inconspicuous could be formed on any of the recording media. Further, compared with the head of the first embodiment, the speed could be improved at the same cost.

[0073]

[Table 1]

Embodiment 3 (Claims 5 and 6) ● Head for image formation ◆ Head 1 ・ Structure: FIG. 7 (A) ・ Light source: The above light source (1) ・ Number of light sources: 19 ・ Number of light source sets: 10・ Light source arrangement: <high-density interval> 10 μm ◆ Head 2 ・ Configuration: FIG. 7 (B) ・ Light sources: the above light sources (1) ・ Number of light sources: 22 ・ Number of light source groups: 6 ・ Light source arrangement: <1 pixel or more Spacing> 20 μm, <high density spacing> 10 μm

The above two types of heads are used in an apparatus having the structure shown in FIG. 2, and each recording medium shown in Example 1 is mounted on a drum as shown in FIG. 2B, and the drum is rotated at a drum rotation speed of 67 rpm.
As a result of forming an image at 1270 dpi, it was confirmed that a high-quality image in which the boundaries of the images by the respective light source sets were inconspicuous could be formed on any recording medium. In addition, although the image data transfer control method differs depending on the head configuration, it was confirmed that the optimum head configuration differs depending on the shift amount of the light source.

[0076]

[Table 2]

Embodiment 4 (Claims 7 and 8) ◆ Head 1 ・ Configuration: FIG. 7 (A) ・ Light source: the above light source (1) ・ Number of light sources: 19 ・ Number of light source sets: 10 ・ Arrangement of light sources: < High-density interval> 10 μm ◆ Head 2 ・ Configuration: FIG. 7 (B) ・ Light source: the above-mentioned light sources (1) ・ Number of light sources: 22 ・ Number of light source sets: 6 ・ Light source arrangement: <interval of one pixel or more> 20 μm, <High density interval> 10 μm

Using the two types of heads in the apparatus having the structure shown in FIG. 2, each recording medium shown in Example 1 was mounted on a drum as shown in FIG. 2B, and the drum was rotated at a drum rotation speed of 67 rpm.
As a result of forming an image at 1270 dpi, it was confirmed that a high-quality image in which the boundaries of the images by the respective light source sets were inconspicuous could be formed on any recording medium.

[0079]

[Table 3]

Fifth Embodiment (Claim 9) Each recording medium shown in the first embodiment is used as shown in FIG. 2B by using the heads of the first to fourth embodiments in an apparatus having the structure shown in FIG. As a result of image formation performed at a drum rotation speed of 67 rpm and at a resolution of 1270 dpi so that images of adjacent light source sets overlap each other by 2 to 3 pixels at a drum rotation speed, each of the recording media It has been confirmed that a high-quality image in which the boundaries of the images by the light source set are not noticeable can be formed.

[0081]

[Table 4]

Embodiment 6 (Claim 10) Each recording medium shown in Embodiment 1 is used as shown in FIG. 2B by using the heads of Embodiments 1 to 4 in an apparatus having the structure shown in FIG. As a result of performing image formation at 1270 dpi resolution at a drum rotation speed of 67 rpm by attaching to a drum so that images of adjacent light source sets overlap each other by a half pixel width,
It was confirmed that a high-quality image in which the boundaries of the images by each light source set were inconspicuous could be formed on any of the recording media.

[0083]

[Table 5]

Embodiment 7 (Claim 11) Each recording medium shown in Embodiment 1 is used as shown in FIG. 2B by using the heads of Embodiments 1 to 4 in an apparatus having the structure shown in FIG. The two light sources at the end of each light source set are written with the same data at 1270 dpi resolution at a drum rotation speed of 67 rpm when mounted on the drum, and the boundary of the image by each light source set is written to any recording medium. It was confirmed that a high quality image could be formed without noticeable.

[0085]

[Table 6]

Eighth Embodiment (Claim 12) Each recording medium shown in the first embodiment is used as shown in FIG. 2B by using the heads of the first to fourth embodiments in an apparatus having the structure shown in FIG. At the drum rotation speed of 67 rpm when mounted on the drum, the data for the two light sources at the end of each light source set is the same data at 1270 dpi resolution according to the amount of shift in the direction perpendicular to the drum rotation direction. By setting and writing the same data for the light source at the end of the target light source set and the light source at the target light source side of the adjacent light source, each light source set can be written to any recording medium. It was confirmed that a high-quality image in which the boundaries of the images due to the image were not conspicuous could be formed. The amount of displacement of each light source set was read by observing the image on the recording medium with a 200 × optical microscope.

[0087]

[Table 7]

Embodiment 9 (Claim 13) Encoder: (output) 5000 pulses / rotation Each recording medium of Embodiment 1 is mounted on a drum as shown in FIG. 2 using an image forming apparatus having the configuration shown in FIG. 6 (B) and 7 (B) are used as image forming heads, and the rotation speed of the recording drum is detected by a 5000p.
A / r output encoder was provided on the recording drum shaft. Next, as for the image data transfer control unit, three image data transfer control units are manufactured using a programmable IC in the image data transfer control unit as shown in FIG. ) Or 7, 7, 5 (total 19) LDs. The main input signals to the image data transfer control unit are an encoder output signal, a 20 MHz system clock, image data, and other control signals. The output signals are mainly transmitted to two destinations. A 1 MHz clock corresponding to the number of image data desired to be acquired is transmitted to the image data supply source which is the transmission destination, and a light source corresponding to each light source is transmitted to the light source drive control unit which is the second transmission destination. It is a drive signal. The reset signal of the image data transfer clock was generated from the encoder output signal and the system clock. As a result of performing image formation using the above-described system, it has become possible to perform high-quality image formation in which the variation in the writing start position of each line is several μm.

[0089]

[Table 8]

Embodiment 10 (Claim 14) Recording medium: 180 μm thick PET film + 10 μm
1. Carbon layer containing thick wax fine particles + 1 μm thick silicone resin layer Ink used

[0091]

[Table 9]

Example 1 using the above-mentioned recording medium,
An image was formed under the same conditions as described above, and development was performed using the ink. As a result, good plate making with less variation in pixel position could be performed.

Embodiment 11 (Claim 15) Recording medium Material 1: Fluorine-containing acrylate material (LS317
[Asahi Glass]) ・ Material 2: Mixed material of fluorinated acrylate resin and urethane resin (RHC12 [Asahi Glass]) ・ Substrate 1: Direct mat PET film sheet (3
50 × 540 mm, 100 μm thickness) +6 μm thickness carbon layer (light absorbing layer) ・ Substrate 2: Direct mat PET film roll (3
1. 50 mm × 10 m, 50 μm thick) +6 μm thick carbon layer (light absorbing layer) Contact liquid used for image formation: water A transparent PET film that transmits laser light is disposed on the surface of the recording medium, and a thin layer of water is held between the recording medium and the film. Is LD under the same conditions as in Example 1 (however, the laser head uses (2)).
Image formation was performed with the drive timing determined, and development was performed using the ink of Example 10. As a result, good plate making with a low output LD and little pixel position variation in the sub-scanning direction could be performed.

Example 12 (Claim 16) Pretreatment of Recording Medium Polyethylene glycol # 600 heated to 90 ° C. was brought into contact with the surface of the recording medium having an ink-repellent surface state for 30 seconds, and then the recording medium was run with running water. The polyethylene glycol adhered to the surface is washed, and the polyethylene glycol and water are removed and dried to make the surface of the recording medium excellent in ink adhesion. An image is formed by using the recording medium and heating the non-image area under the same conditions as in the first embodiment (except that the laser head uses (2)) except for the LD drive timing. Example 10
As a result, it was possible to perform good plate making with a low output LD with little variation in the pixel position in the sub-scanning direction.

Example 13 (Claim 17) Recording paper: fine paper, lightly coated paper, coated paper, art paper,
Synthetic paper, plain paper Example 10 using each apparatus of FIGS.
When printing was performed under the conditions of Nos. And 12, good images could be obtained on the recording paper.

Embodiment 14 (Claim 18) Under the conditions of Embodiment 13, images were formed on each color plate using the apparatus shown in FIGS. 17 and 18. It was confirmed that an image was obtained.

[0097]

According to the first aspect of the present invention, in order to make the boundaries between images formed by a plurality of light sources less conspicuous than in the conventional image forming head, it is possible to achieve this with a device / data control system having a simple configuration. .

According to the second aspect of the present invention, it is possible to form a high-quality image by using a control system having a simple configuration, in which the boundaries between images formed by a plurality of light sources are less noticeable than in a conventional image forming apparatus.

According to the third aspect of the present invention, compared to the image forming head of the first aspect, the boundary between images formed by a plurality of light sources can be made less noticeable by a data transfer control system having a simpler configuration. It becomes possible.

According to the fourth aspect of the present invention, compared to the image forming apparatus of the second aspect, the data transfer control system having a simple configuration can form a high-quality image by using a plurality of light sources with less noticeable image boundaries. It becomes possible.

According to the fifth aspect of the invention, as compared with the image forming heads of the first and third aspects, the labor required for manufacturing the head can be further reduced, and a data transfer control system having a simple configuration can be realized. .

According to the sixth aspect of the present invention, compared to the image forming apparatuses of the second and fourth aspects, a data transfer control system having a simpler configuration can form a high-quality image by using a plurality of light sources with less noticeable image boundaries. It is possible to do.

According to the invention of claim 7, according to claims 1, 3,
As compared with the image forming head of No. 5, the labor and cost required for manufacturing the head can be further reduced.

According to the eighth aspect of the present invention, the second, fourth,
As compared with the image forming apparatus of No. 6, it is possible to form a high-quality image by using a lower-cost apparatus in which the boundaries between the images formed by the plurality of light sources are not noticeable.

According to the ninth aspect of the present invention, the second aspect, the fourth aspect,
Compared to the image forming apparatuses 6 and 8, the boundaries between the images formed by the plurality of light sources can be made less noticeable, and the labor required for the apparatus adjustment can be reduced.

According to the tenth aspect of the present invention, it is possible to make the boundaries between images formed by a plurality of light sources less noticeable than in the image forming apparatus of the ninth aspect.

According to the eleventh aspect, the second aspect,
As compared with the image forming apparatuses of 4, 6, 8 to 10, it is possible to make the boundaries between images formed by a plurality of light sources less noticeable, and to reduce the labor required for adjusting the apparatuses.

According to the twelfth aspect, in the second aspect,
Compared to the image forming apparatuses of 4, 6, 8 to 11, the boundaries between images formed by a plurality of light sources can be made less noticeable, and the labor required for adjusting the apparatus can be reduced.

According to the invention of claim 13, claim 2,
As compared with the image forming apparatuses of 4, 6, 8 to 12, the stability of the image quality against the apparatus vibration is improved.

According to the fourteenth aspect, the second aspect,
It becomes possible to make a printing plate material for the image forming apparatuses 4, 6, 8 to 13.

According to the fifteenth aspect, it is possible to construct a low-cost system as compared with the image forming apparatus according to the fourteenth aspect.

According to the sixteenth aspect of the present invention, it is possible to provide an apparatus having improved handleability as compared with the image forming apparatus of the fifteenth aspect.

According to the seventeenth aspect, claims 14 to
For the sixteen image forming apparatuses, it is possible to obtain high-quality images on recording paper.

According to the eighteenth aspect, claims 1 to 1 are provided.
7, a high-quality multicolor image can be obtained on recording paper.

[Brief description of the drawings]

FIG. 1 is a view showing an image forming head according to claim 1;

FIG. 2 is a diagram illustrating an image forming apparatus according to a second embodiment.

FIG. 3 is a diagram illustrating an image forming head according to a third embodiment.

FIG. 4 is a diagram for explaining mutual images generated by adjacent light source sets in the image forming apparatus according to claim 9;

FIG. 5 is a diagram for explaining mutual images generated by adjacent light source sets in the image forming apparatus according to claim 10;

FIG. 6 is a view showing an image forming head according to claim 5;

FIG. 7 is a view showing an image forming head according to claim 7;

FIG. 8 is a diagram for describing an example of image formation of an N-th light source set and an (N + 1) -th light source set in the image forming apparatus according to claim 12;

FIG. 9 is a diagram illustrating an example of the configuration of an image forming apparatus according to claim 13;

FIG. 10 is a block diagram of a transfer system of image data supplied to a light source in the image forming apparatus according to claim 13;

FIG. 11 is a diagram illustrating a recording medium used by the image forming apparatus according to claim 14;

FIG. 12 is a diagram illustrating a recording medium used by the image forming apparatus according to claim 15;

FIG. 13 is a diagram illustrating a recording medium used by the image forming apparatus according to claim 16;

FIG. 14 is a diagram illustrating an example of an image forming apparatus according to claim 17;

FIG. 15 is a diagram showing another example of the image forming apparatus according to claim 17;

FIG. 16 is a view showing still another example of the image forming apparatus according to claim 17;

FIG. 17 is a diagram illustrating an example of the image forming apparatus according to claim 18;

FIG. 18 is a diagram illustrating another example of the image forming apparatus according to claim 18;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Recording medium, 2 ... Recording medium holding drum, 3 ... Image forming head, 4 ... Light source, 4a ... Light source set, 5 ... Stepping motor, 6 ... Drum rotation position detection means, 7 ... Image data transfer control means, 8 ... Image data transfer clock generator 9
... Data receiving unit, 10 ... Data distribution unit, 11 ... Delay generation unit, 12 ... Light source drive signal output unit

Claims (18)

[Claims] 1. An image forming head comprising: a plurality of light source sets each including one or a plurality of light sources arranged to irradiate a recording medium on which an image is to be formed by heating while being held by a recording medium holding drum; A plurality of light sources at at least one end of at least one or more light source sets of a light source set having a plurality of light sources have an image resolution pixel spacing or less in a direction perpendicular to the recording medium holding drum rotation direction. And an image forming head, which is arranged at a high density. 2. An image forming apparatus using the image forming head according to claim 1. 3. The image forming head according to claim 1, wherein the target light source groups of a plurality of light source groups adjacent to the target light source group having a plurality of light sources arranged at a high density are densely arranged. The plurality of light sources at the end closer to the plurality of light sources are not arranged at high density. 4. An image forming apparatus using the image forming head according to claim 3. 5. The image forming head according to claim 1, wherein all of the light source sets having a plurality of light sources have light sources arranged at high density, and the light source positions of the high density arrangement in each of the light source sets are the image positions of the image. An image forming head which is unified on the left side or the right side from the forming head to the recording medium holding drum. 6. An image forming apparatus using the image forming head according to claim 5. 7. The image forming head according to claim 1, wherein light sources at both ends of the image forming head are not arranged at a high density. 8. An image forming apparatus using the image forming head according to claim 7. 9. The image forming apparatus according to claim 2, wherein the plurality of light sources arranged at a high density include a region where an end light source among the plurality of light sources forms an image. An image forming apparatus that forms an image such that an area where an image is formed by a light source set adjacent to the light source on the end side at least partially overlaps. 10. The image forming apparatus according to claim 9, wherein an overlapping amount of images formed by adjacent light source sets is:
An image forming apparatus, wherein the image resolution is less than one pixel width of the image resolution. 11. The image forming apparatus according to claim 2, wherein at least two lines at a boundary between adjacent light source sets form an image with data of the same content. Characteristic image forming apparatus. 12. The image forming apparatus according to claim 2, wherein a laser beam emitted from each light source set is irradiated on said recording medium in a direction perpendicular to a rotation direction of a recording medium holding drum. An image forming apparatus for determining the contents of data to be transferred to edge light sources arranged at high density based on the state of misalignment. 13. The image forming apparatus according to claim 2, further comprising: a drum position detecting unit configured to detect a position of the recording medium holding drum, and the drum position detecting unit. An image forming apparatus which determines image data transfer timing based on the information of the image forming apparatus. 14. The image forming apparatus according to claim 2, wherein the recording medium has a property that ink adhesion characteristics are different between a heated area and a non-heated area. Image forming apparatus. 15. The image forming apparatus according to claim 14, wherein when the recording medium is brought into contact with the liquid in a heated state, the receding contact angle is reduced (lyophilic state) and the recording medium is heated in a non-contact state with the liquid. An image forming apparatus having a surface characteristic in which a receding contact angle increases (a liquid repellent state) when the image forming apparatus is operated. 16. The image forming apparatus according to claim 15, wherein the non-image area is heated to form an image. 17. The image forming apparatus according to claim 14, further comprising: a developing unit for adhering ink to an image area of the recording medium, and receiving the ink image from the recording medium and forming the ink image on recording paper. An image forming apparatus comprising: an intermediate transfer body for transferring; and an impression cylinder. 18. The image forming apparatus according to claim 2, further comprising: a recording medium, a recording medium holding unit, and a developing device in the image forming apparatus according to claim 14. A multicolor image forming apparatus having a plurality of units.