JP2005335400A - Image recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dramatically increase selectable sizes of recording sheets by well maintaining a balance among suction force applied on the recording sheet changeable by the sizes of the recording sheets by a vacuum means, centrifugal force applied on the recording sheet changeable by the rotating speed of a rotating drum, and releasing force by an air flow, without decreasing the quality of the image recorded. <P>SOLUTION: The image recording apparatus is equipped with the rotating drum which is hollow and is provided with a plurality of through-holes penetrating inward from the peripheral face, and holds the recording sheet wound and rotates, and the vacuum means making the inside of the rotating drum vacuum, and records the image on the recording sheet wound on the rotating drum. The image recording apparatus is characterized by making the density of the holes provided in a region on which the recording sheet is wound in the vicinity of the edge positions of the recording sheet higher than the density of the holes provided in other region when the recording sheet is wound on the rotating drum. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image recording apparatus for recording an image on a recording sheet wound around a rotary drum.

  Conventionally, as an image recording apparatus for recording an image on a recording sheet, the recording sheet is wound around a rotating drum, and an image is recorded on the recording sheet wound around the rotating drum. A rotating drum that is provided with a plurality of through holes and that rotates while holding the wound recording sheet; and a decompression unit that decompresses the inside of the rotating drum, and the rotation drum is decompressed by the decompression by the decompression unit. It is known that an image is recorded on the recording sheet by closely contacting the recording sheet wound around the circumferential surface of the recording sheet to the rotating drum.

  However, in such an image recording apparatus, the suction force by the decompression unit applied to the recording sheet varies depending on the size of the recording sheet, and depending on the rotational speed of the rotating drum, the centrifugal force and the air current applied to the recording sheet The peeling force is superior, and there is a problem that the recording sheet peels from the rotating drum.

  An object of the first invention is to solve the above-described problems, and increases the suction force by the pressure reducing means applied to the recording sheet at a low cost to increase the rotational speed of the rotating drum to the recording sheet. The recording speed can be increased, the allowable range for the deviation of the edge position of the recording sheet can be increased, and further, the image can be stably recorded on the recording sheet without deteriorating the quality of the recorded image. Is to do so.

  It is also conceivable to provide a connecting groove for connecting the plurality of holes on the peripheral surface of the rotating drum of the conventional image recording apparatus so that the recording sheet is uniformly adhered to the rotating drum. However, if the connecting groove is simply provided, air leaks from the connecting groove straddling the edge position of the recording sheet, and the suction force by the decompression means applied to the recording sheet becomes insufficient. Depending on the rotational speed of the rotating drum, the recording The centrifugal force applied to the sheet and the peeling force due to the air current are superior, and there is a problem that the recording sheet peels from the rotating drum.

  The object of the second invention is to solve the above-mentioned problems, suppress air from leaking from the connecting groove at low cost, increase the suction force by the decompression means applied to the recording sheet, and The recording sheet is increased without increasing the recording speed on the recording sheet, increasing the allowable range for deviation of the edge position of the recording sheet, and further reducing the quality of the recorded image. This is to enable stable recording of images.

  Further, in the conventional image recording apparatus, the rotating drum and the recording head unit for recording an image on a recording sheet wound around the rotating drum are provided horizontally in the center of the apparatus, so that the vibration of the rotating drum is Is easily transmitted to the recording head, and the vibration of the entire apparatus tends to be large. Therefore, if a heavy strength member is provided around the rotating drum in order to suppress vibration of the rotating drum, the weight of the entire apparatus increases, the load bearing strength of the housing increases, and the entire apparatus increases. Weight increases. Further, since the recording head is arranged horizontally with the rotating drum, the workability of adjustment work such as parallel adjustment of the axis of the rotating drum and the scanning axis of the recording head is poor, and the space on one side of the rotating drum in the horizontal direction is also poor. Is occupied by the recording head unit, and the degree of freedom of installation of a mechanism for feeding / discharging the recording sheet is small, and the whole apparatus tends to be enlarged.

  The object of the third invention is to solve the above-mentioned problems. A rotating drum which is a main cause of apparatus vibration is provided at the bottom of the apparatus, and heavy strength members for preventing apparatus vibration are collected at the bottom of the apparatus. The overall weight is reduced, the vibration of the entire device and the load bearing strength of the housing are suppressed, and the workability of adjustment work such as parallel adjustment of the axis of the rotating drum and the scanning axis of the recording head is improved. In addition, the space on both sides of the rotating drum in the horizontal direction is secured, the degree of freedom of installation of the mechanism for feeding and discharging recording sheets is increased, and the entire apparatus can be downsized. is there.

  Further, in the conventional image recording apparatus, as the edge position of the recording sheet wound around the rotating drum deviates from the normal position, the suction force by the decompression unit applied to the recording sheet changes. It was necessary to prevent the edge position of the wound recording sheet from deviating from the normal position with high accuracy. Therefore, in the conventional image recording apparatus, the position accuracy of the pressure bonding position of the squeeze roller when feeding the recording sheet to the rotating drum is made high, and the position of the recording sheet is adjusted to the pressure bonding position of the rotating drum and the squeeze roller. Positioning the tip position has been performed.

  However, according to this method, it is difficult to stably position the leading end position of the recording sheet at the correct position, and the position accuracy of the pressing position of the squeeze roller when feeding the recording sheet to the rotating drum is high. There was a need to make things.

  The object of the fourth invention is to solve the above-mentioned problems, and high accuracy is not required for the position accuracy of the squeeze roller pressing position when feeding the recording sheet to the rotating drum, and the accuracy is assured. It is possible to position the leading edge of a recording sheet having a high height, and to suppress the peeling force caused by the air current acting on the leading edge of the recording sheet when recording an image on the recording sheet wound around the rotating drum, with a simple structure. In other words, the quality of the recorded image can be stably improved.

  The object of the fifth invention is to solve the above-described problems, and the recording sheet changes depending on the suction force by the decompression means applied to the recording sheet, which changes according to the size of the recording sheet, and the rotational speed of the rotating drum. Is to maintain a good balance with the centrifugal force and the peeling force due to the air current, and to dramatically increase the size of the selectable recording sheet without deteriorating the quality of the recorded image.

  Further, in the conventional image recording apparatus, as the edge position of the recording sheet wound around the rotating drum deviates from the normal position, the suction force by the decompression unit applied to the recording sheet changes. It was necessary to prevent the edge position of the wound recording sheet from deviating from the normal position with high accuracy.

  The object of the sixth invention is to solve the above problems, and even if the edge position of the recording sheet changes, the suction force by the decompression means applied to the recording sheet and the rotational speed of the rotary drum By maintaining a good balance with the centrifugal force applied to the recording sheet and the peeling force due to the airflow, etc., and by widening the allowable range of the deviation of the edge position of the recording sheet without deteriorating the quality of the recorded image. is there.

  Further, in the conventional image recording apparatus, the suction force by the pressure reducing unit applied to the recording sheet changes according to the pressure inside the rotating drum, and the centrifugal force applied to the recording sheet depends on the rotation speed of the rotating drum. Further, there is a problem that the peeling force due to the air current is superior and the recording sheet peels from the rotating drum.

  The object of the seventh invention is to solve the above-mentioned problems, and the suction force by the decompression means applied to the recording sheet, which changes depending on the pressure inside the rotary drum, and the rotation speed of the rotary drum change. Maintaining a good balance between the centrifugal force applied to the recording sheet and the peeling force caused by the air current, and a stable mechanism for recording an image on the recording sheet without degrading the quality of the recorded image. Is to do so.

  Further, in the conventional image recording apparatus, the suction force by the decompression unit applied to the recording sheet is insufficient, and depending on the rotational speed of the rotating drum, the centrifugal force applied to the recording sheet and the peeling force by the air current are superior. There is a problem that the recording sheet is peeled off from the rotating drum.

  The above-described object of the present invention can be achieved by all the matters for specifying the invention described in each claim. Each claim will be described below. However, items that overlap with the explanation in the cited paragraph may be omitted. In each claim, unless otherwise specified, it is needless to say that one element of the present invention may be composed of a plurality of members, and one or more members represent a plurality of elements of the present invention. It goes without saying that it may also be combined.

[Invention of Claim 1] (First Invention) “A hollow, a plurality of holes penetrating from the circumferential surface to the inside, a rotating drum that holds and rotates a wound recording sheet;
Decompression means for decompressing the inside of the rotating drum,
In an image recording apparatus for recording an image on a recording sheet wound around the rotating drum,
The density of the holes provided in the area where the recording sheet is wound in the vicinity of the edge position of the recording sheet when the recording sheet is wound around the rotating drum is higher than the density of the holes provided in other areas. An image recording apparatus characterized by high density. ]
According to the first aspect of the present invention, it is possible to increase the suction force by the pressure reducing unit applied to the recording sheet at a low cost, and increase the rotational speed of the rotating drum to increase the recording speed on the recording sheet. In addition, an allowable range for deviation of the edge position of the recording sheet is increased, and further, an image can be stably recorded on the recording sheet without deteriorating the quality of the recorded image.

[Invention of Claim 2] “The image recording apparatus according to claim 1, wherein a connecting groove for connecting the plurality of holes is provided on a peripheral surface of the rotating drum. ]
According to the second aspect of the present invention, the recording sheet can be uniformly adhered to the rotating drum without providing a large number of holes on the peripheral surface of the rotating drum, and the large number of holes can be formed on the peripheral surface of the rotating drum. Since it does not need to be provided, the strength of the rotating drum can be maintained, and the suction force from each hole can be increased without a strong pressure reduction.

[Invention of Claim 3] (Second Invention) “A hollow, a plurality of holes penetrating from the circumferential surface to the inside, and a rotating drum that rotates while holding a wound recording sheet;
Decompression means for decompressing the inside of the rotating drum,
In an image recording apparatus for recording an image on a recording sheet wound around the rotating drum,
A connection groove for connecting the plurality of holes to the peripheral surface of the rotating drum is provided,
The image is characterized in that the density of the connecting groove across the edge position of the recording sheet when the recording sheet is wound around the rotating drum is lower than the density of the connecting groove provided in another region. Recording device. ]
According to the third aspect of the present invention, it is possible to suppress air from leaking from the connecting groove at low cost, increase the suction force by the pressure reducing means applied to the recording sheet, and increase the rotation speed of the rotating drum. The recording speed on the recording sheet can be increased, the allowable range for the deviation of the edge position of the recording sheet is increased, and the image on the recording sheet is stabilized without degrading the quality of the recorded image. Can be recorded.

[Invention of Claim 4] “The image recording apparatus according to claim 3, wherein the connecting groove straddling the edge position of the recording sheet when the recording sheet is wound around the rotating drum is absent. ]
According to the fourth aspect of the present invention, even when the edge position of the recording sheet is deviated, the peeling from the edge of the recording sheet can be prevented from growing, and more stable image recording can be performed.

[Invention of Claim 5] (Third Invention) “A hollow, a plurality of holes penetrating from the peripheral surface to the inside, and a rotating drum that holds and rotates the wound recording sheet;
Decompression means for decompressing the inside of the rotating drum;
A recording head unit for recording an image on a recording sheet wound around the rotating drum;
In an image recording apparatus having
An image recording apparatus, wherein the rotary drum is provided at the bottom of the apparatus, and the recording head part is provided above the rotary drum. ]
According to the invention described in claim 5, since the rotating drum which is the main cause of the apparatus vibration is provided at the bottom of the apparatus, heavy strength members for preventing the apparatus vibration can be collected at the bottom of the apparatus, and the weight of the entire apparatus can be reduced. In addition, the vibration of the entire apparatus and the load bearing strength of the housing can be suppressed, and the recording head is arranged above the rotating drum, so that the axis of the rotating drum and the scanning axis of the recording head The workability of the adjustment work such as parallel adjustment is greatly improved. Further, a space on both sides of the rotating drum in the horizontal direction is secured, the degree of freedom of installation of a mechanism for feeding and discharging recording sheets is increased, and the entire apparatus can be downsized.

[Invention of Claim 6] (Fourth Invention) “Having a rotating drum that holds and rotates a wound recording sheet,
In an image recording apparatus for recording an image on a recording sheet wound around the rotating drum,
A squeeze roller that is pressed toward the rotating drum to bring the recording sheet into close contact with the rotating drum when feeding the recording sheet to the rotating drum;
An image recording apparatus, wherein a step is provided on a peripheral surface corresponding to a leading end of the recording sheet of the rotating drum. ]
According to the invention of claim 6, high accuracy is not required for the positional accuracy of the squeeze roller pressing position when feeding the recording sheet to the rotating drum, and the leading end positioning of the recording sheet can be performed reliably and accurately. When the image is recorded on the recording sheet wound around the rotating drum, it is possible to suppress the peeling force due to the air current acting on the leading edge of the recording sheet, and thus to stably improve the quality of the recorded image with a simple structure. Can do.

[Invention of Claim 7] “When feeding the recording sheet to the rotating drum, when the squeeze roller is pressed in the vicinity of the step of the rotating drum, the leading edge of the recording sheet becomes the step. The image recording apparatus according to claim 6, wherein the image recording apparatus is applied. ]
According to the seventh aspect of the present invention, the leading edge of the recording sheet is positioned reliably and accurately, and the peeling force due to the air current acting on the leading edge of the recording sheet when an image is recorded on the recording sheet wound around the rotating drum. Therefore, it is possible to reliably improve the quality of the recorded image with a simple structure.

[Invention of Claim 8] “The rotating drum is hollow, provided with a plurality of holes penetrating from the circumferential surface to the inside, and rotates while holding the wound recording sheet,
The image recording apparatus according to claim 6, further comprising a decompression unit that decompresses the inside of the rotary drum. ]
According to the invention described in claim 8, the deviation of the edge position of the recording sheet can be remarkably reduced at a low cost, and the recording speed is increased by increasing the rotational speed of the rotating drum without deteriorating the quality of the recorded image. The recording speed on the sheet can be increased, and the size of selectable recording sheets can be dramatically increased.

  The above object of the present invention can also be achieved by the invention described below.

(Fifth Invention) “A hollow, a plurality of holes penetrating from the circumferential surface to the inside, a rotating drum that holds and rotates the wound recording sheet;
Decompression means for decompressing the inside of the rotating drum,
In an image recording apparatus for recording an image on a recording sheet wound around the rotating drum,
Images can be recorded on recording sheets of multiple sizes,
An image recording apparatus characterized in that the rotational speed of the rotary drum is changed in accordance with the size of a recording sheet wound around the rotary drum. ]
According to the fifth invention, the balance between the suction force by the decompression means applied to the recording sheet that changes depending on the size of the recording sheet, the centrifugal force applied to the recording sheet that changes according to the rotational speed of the rotating drum, and the peeling force caused by the air current. Can be maintained well, and the size of the selectable recording sheet can be dramatically increased without degrading the quality of the recorded image.

(Sixth invention) “A hollow, a plurality of holes penetrating from the circumferential surface to the inside, and a rotating drum that rotates while holding a wound recording sheet;
Decompression means for decompressing the inside of the rotating drum,
In an image recording apparatus for recording an image on a recording sheet wound around the rotating drum,
Edge position detecting means for detecting the edge position of the recording sheet wound around the rotating drum;
An image recording apparatus characterized in that the rotational speed of the rotary drum is changed in accordance with the edge position of the recording sheet detected by the edge position detecting means. ]
According to the sixth invention, by changing the rotational speed of the rotating drum according to the edge position of the recording sheet detected by the edge position detecting means, the suction force by the decompression means on the recording sheet, It is possible to maintain a good balance with the centrifugal force applied to the recording sheet, which varies depending on the rotational speed of the rotating drum, and the peeling force due to the air current, and without degrading the quality of the recorded image, the deviation of the edge position of the recording sheet can be prevented. The tolerance is widened.

(Seventh invention) “A hollow, rotating drum that is provided with a plurality of holes penetrating from the circumferential surface to the inside, and rotates while holding the wound recording sheet;
Decompression means for decompressing the inside of the rotating drum,
In an image recording apparatus for recording an image on a recording sheet wound around the rotating drum,
Pressure detecting means for detecting the pressure inside the rotating drum when a recording sheet is wound around the rotating drum;
An image recording apparatus characterized in that the rotational speed of the rotary drum is changed according to the pressure inside the rotary drum detected by the pressure detection means. ]
According to the seventh invention, the rotation force of the rotating drum is changed according to the pressure inside the rotating drum detected by the pressure detecting means, so that the suction force by the decompressing means on the recording sheet and the rotation The balance between the centrifugal force applied to the recording sheet, which varies depending on the rotation speed of the drum, and the peeling force due to the airflow, can be kept good, and the image can be transferred to the recording sheet with a simple mechanism without reducing the quality of the recorded image. Can be recorded stably.

  In any one of the fifth to seventh inventions, by providing a connecting groove for connecting the plurality of holes to the peripheral surface of the rotating drum, the rotating drum can be provided without providing a large number of holes on the peripheral surface of the rotating drum. In addition, the recording sheet can be uniformly adhered to each other, and since it is not necessary to provide a large number of holes on the peripheral surface of the rotating drum, the strength of the rotating drum can be maintained, and even without strong decompression, The suction force from each hole can be increased.

[Terminology and other explanations]
The recording sheet is a sheet on which an image is recorded by the image recording apparatus of the present invention. Even if the latent image is recorded by the image recording apparatus of the present invention, the recording sheet is a sheet on which a visible image is recorded. May be. The image recording apparatus of the present invention may record an image on a recording sheet with light, may record an image on a recording sheet with X-rays, or may record another image on a recording sheet. An image may be recorded by a method, but the present invention is particularly useful and preferable for recording an image on a recording sheet by irradiating the recording sheet with a laser beam. The image recording by the laser beam may be one in which the recording sheet is altered by the thermal energy of the laser beam, the recording sheet may be exposed by the light energy of the laser beam, or other It may depend on the form.

  According to the first invention, the suction force by the decompression means applied to the recording sheet is increased at a low cost, the rotational speed of the rotating drum is increased to increase the recording speed on the recording sheet, and the recording sheet It is possible to stably record an image on the recording sheet without increasing the allowable range for the deviation of the edge position and further reducing the quality of the recorded image.

  According to the second invention, it is possible to suppress the leakage of air from the connection groove at low cost, increase the suction force by the pressure reducing means applied to the recording sheet, and increase the rotational speed of the rotating drum to perform recording on the recording sheet. The image can be stably recorded on the recording sheet without increasing the speed, increasing the allowable range for the deviation of the edge position of the recording sheet, and further reducing the quality of the recorded image.

  According to the third invention, since the rotating drum which is the main cause of the apparatus vibration is provided at the bottom of the apparatus, heavy strength members for preventing the apparatus vibration can be collected at the bottom of the apparatus, and the weight of the entire apparatus is reduced. In addition, the vibration of the entire apparatus and the load bearing strength of the housing can be suppressed. Further, since the recording head is arranged above the rotating drum, the parallel adjustment of the axis of the rotating drum and the scanning axis of the recording head is possible. The workability of such adjustment work is greatly improved. Further, a space on both sides of the rotating drum in the horizontal direction is secured, the degree of freedom of installation of a mechanism for feeding and discharging recording sheets is increased, and the entire apparatus can be downsized.

  According to the fourth invention, high accuracy is not required for the position accuracy of the pressure bonding position of the squeeze roller when feeding the recording sheet to the rotating drum, and the leading edge positioning of the recording sheet can be performed reliably and accurately. When recording an image on a recording sheet wound around a rotating drum, the peeling force due to the air current acting on the tip of the recording sheet can be suppressed, and the quality of the recorded image can be stably improved with a simple structure. .

  According to the fifth invention, the balance between the suction force by the decompression means applied to the recording sheet that changes depending on the size of the recording sheet, the centrifugal force applied to the recording sheet that changes according to the rotational speed of the rotating drum, and the peeling force caused by the air current. The recording sheet size that can be selected can be dramatically increased without deteriorating the quality of the recorded image.

  According to the sixth invention, even if the edge position of the recording sheet is changed, the suction force by the pressure reducing means applied to the recording sheet, and the separation by the centrifugal force and the air current applied to the recording sheet that changes depending on the rotation speed of the rotating drum. It is possible to widen the allowable range of the deviation of the edge position of the recording sheet without degrading the quality of the recorded image while maintaining a good balance with the force.

  According to the seventh invention, the suction force by the pressure reducing means applied to the recording sheet that changes according to the pressure inside the rotating drum, the centrifugal force applied to the recording sheet that changes according to the rotational speed of the rotating drum, and the peeling force caused by the air current The image can be stably recorded on the recording sheet with a simple mechanism without degrading the quality of the recorded image while maintaining a good balance.

  Examples of specific examples relating to the present invention are shown below as embodiments and examples, but the present invention is not limited to these. In addition, although there are assertive expressions for terms and the like in the embodiments and examples, they show preferred examples of the present invention and do not limit the meaning or technical scope of the terms of the present invention.

  The image recording apparatus of this embodiment is an apparatus for recording a latent image on a photographic film for plate making, which is a silver halide monochrome photographic material provided with a photosensitive layer sensitive to red light, and a plurality of laser beams of red light. Are simultaneously generated and irradiated on the plate-making photographic film that moves in the sub-scanning direction while being aligned in the main scanning direction MSD, so that the plate-making photographic film (hereinafter, this plate-making photographic film is the present invention). This is a recording sheet, and is called a recording sheet.) A device for recording a latent image. FIG. 1 shows a schematic front view of the image recording apparatus of this embodiment, FIG. 2 shows a schematic side view of the image recording apparatus of this embodiment, and FIG. 3 shows a partially enlarged side view of FIG. Hereinafter, the image recording apparatus according to the present embodiment will be described with reference to FIGS. 1, 2, and 3.

  In the recording head unit 1, a plurality of (for example, 10) laser diodes LD 10 to LD 19 are arranged and arranged, and a plurality of laser diodes LD 10 to LD 19 emitted from the light source unit 10 are emitted. A beam alignment optical system 20 is provided on the recording surface of the plate-making photographic film in which the two laser beams are wound around the rotary drum 2 to align the laser beams in the main scanning direction MSD.

  The rotating drum 2 winds and fixes a photographic film for plate making. When an image is recorded, the rotating drum 2 rotates at a constant speed, and thereby a plurality of laser beams emitted from a plurality of laser diodes LD10 to LD19 and the plate making. The photographic film is relatively moved in the sub-scanning direction SSD. The rotating drum 2 is hollow and has a large number of holes penetrating from the peripheral surface to the inside, as will be described later, and rotates while holding the wound recording sheet.

  The rotating drum 2 is connected to a drum motor 27 for rotating the rotating drum 2 via a shaft 28 of the rotating drum 2, and is rotated by the drum motor 27.

  The rotating drum 2 has a cylindrical shape with a closed surface on the shaft 28 side, and the other cylindrical inner surface is rotatably held by a disk-shaped holding plate 31 and has a hole penetrating from the circumferential surface to the inside. Except for this, the structure is such that outside air does not leak into the rotary drum 2. A decompression pump 29 that decompresses the inside of the rotary drum 2 is connected via a pipe 30 through a hole provided in the holding plate 31. Then, when the decompression pump 29 is operated, the inside of the rotary drum 2 is decompressed. Further, the holding plate 31 is provided with a pressure detector 32 for detecting the pressure inside the rotating drum 2 when the recording sheet is wound around the rotating drum 2.

  The recording head unit 1 is fixed to the shaft 12 of the actuator 11 and can be moved in the main scanning direction MSD by the actuator 11. A shaft 13 is also provided on the opposite side of the shaft 12, and a shaft holding member 14 is provided for slidably holding the shaft 13, so that the recording head unit 1 can be stably moved in the main scanning direction MSD. Can be moved. The recording head unit 1 moves in the main scanning direction MSD with respect to the rotating drum 2 to record a latent image on the entire plate-making photographic film wound and fixed on the rotating drum 2. .

  The rotary drum 2 was provided at the bottom of the apparatus, and the recording head unit 1 was provided above the rotary drum 2. Thereby, since the rotating drum 2 which is the main cause of the apparatus vibration is provided at the bottom of the apparatus, heavy strength members for preventing the apparatus vibration can be collected at the bottom of the apparatus, and the weight of the entire apparatus can be reduced. Further, the vibration of the entire apparatus and the load resistance strength of the housing can be suppressed, and furthermore, since the recording head unit 1 is disposed above the rotating drum 2, the axis of the rotating drum 2 and the scanning axis of the recording head unit 1 are provided. The workability of the adjustment work such as parallel adjustment with is greatly improved. Further, a space on both sides in the horizontal direction of the rotating drum 2 is secured, the degree of freedom of installation of a mechanism for feeding and discharging recording sheets is increased, and the entire apparatus can be miniaturized.

  The light receiving element 3 is provided on the same plane as the recording surface of the photographic film for plate making using a plurality of laser beams. Then, the recording head unit 1 moves in the main scanning direction MSD so that a plurality of laser beams are incident on the light receiving element 3, so that the light receiving element 3 is emitted from the plurality of laser diodes of the light source unit 10. The beam intensity of each laser beam is measured.

  Then, the control unit 4 shown in FIG. 4 which is a block diagram of the image recording apparatus of the present embodiment makes the beam intensity of each laser beam equal according to the beam intensity of each laser beam measured by the light receiving element 3. In addition, each laser diode of the plurality of laser diodes of the light source unit 10 is controlled.

  The light source unit 10 is provided with ten laser diodes LD10 to LD19 aligned at a predetermined interval. The ten laser diodes LD <b> 10 to LD <b> 19 are arranged so as to irradiate the laser beam toward the center point CP before the lens 21.

  The beam alignment optical system 20 includes the following. The lens 21 collimates the ten laser beams emitted from these ten laser diodes. The mirror 22 reflects the 10 laser beams parallel with the lens 21 at a right angle, and the mirror 23 reflects the 10 laser beams at a right angle and enters the converging lens unit 24. Let Then, the 10 laser beams incident on the converging lens unit 24 are converged to the convergence point CS. Then, ten laser beams that have passed through the convergence point CS are incident on the reduction optical lens group 25. Then, the reduction optical lens group 25 reduces the incident 10 laser beams on the recording surface RS on the recording sheet wound on the rotary drum 2 to form an image. The ten laser beams emitted from the reduction optical lens group 25 are incident on the cylindrical lens 26. The cylindrical lens 26 is a lens having a refractive power only in the sub-scanning direction. The cylindrical lens 26 is converged so that the positions of the ten laser beams in the recording surface RS in the sub-scanning direction are constant, and has a constant beam diameter BR. These 10 laser beams are aligned on the recording surface RS with a constant beam pitch BP in the main scanning direction MSD.

  Then, while the rotating drum 2 makes one rotation, the recording head unit 1 moves around the rotating drum 2 by moving a certain amount of movement FQ (= 10 × BP) in the main scanning direction MSD with respect to the rotating drum 2. The latent image is recorded uniformly on the entire plate-making photographic film that is rotated and fixed. The beam diameter BR and the beam pitch BP are on the order of several μm to several tens of μm.

  The light receiving element 3 can simultaneously detect the light amount distribution in the main scanning direction MSD on the recording surface RS, like a one-dimensional CCD image pickup element or a two-dimensional CCD image pickup element. When the recording head unit 1 moves so as to be incident, the beam intensity for each laser beam emitted from the plurality of laser diodes LD10 to LD19 can be detected. Then, the control unit 4 controls each laser diode of the plurality of laser diodes of the light source unit 10 so that the beam intensity of each laser beam becomes equal according to the beam intensity of each laser beam measured by the light receiving element 3. To do.

  Next, a mechanism for cutting the recording sheet stored in the magazine 5 into a predetermined size and winding it around the rotary drum 2 will be described. In the magazine 5, a web-shaped recording sheet having a certain width is stored in a roll shape. The feeding unit 6 feeds the recording sheet from the magazine 5 to the rotary drum 2, and operates the cutter 62 when a predetermined length from the leading end of the recording sheet reaches the cutting position of the cutter 62. The recording sheet is cut at a predetermined length from the leading end of the recording sheet, and the recording sheet having a predetermined length is wound around the rotary drum 2.

  The feeding section 6 is provided with feeding roller pairs 61 and 63 so as to sandwich the cutting position of the cutter 62. The feeding is stopped only when the cutter 62 cuts the recording sheet, and the feeding roller 6 is stabilized at a predetermined length. So that it can be disconnected.

  The recording sheet fed by the feeding roller pair 61 and 63 of the feeding unit 6 is guided to the rotary drum 2 by the guides 64 and 65. In addition, a squeeze roller 42 is provided that is pressed against an area where the recording sheet is guided by the guides 64 and 65 of the rotary drum 2. When the recording sheet is fed to the rotating drum 2, the squeeze roller 42 is pressed toward the rotating drum 2, presses the fed recording sheet so as to be in close contact with the rotating drum 2, and records on the rotating drum 2. When the sheet has been fed, the sheet is retracted from the rotating drum 2.

  Further, a step 41 is provided on the circumferential surface corresponding to the leading edge of the recording sheet of the rotary drum 2. When the recording sheet is fed to the rotating drum 2, when the squeeze roller 42 is pressed near the step 41 of the rotating drum 2, the leading end of the recording sheet is applied to the step 41 and the leading end of the recording sheet is stepped. 41 is positioned. As a result, high accuracy is not required for the position accuracy of the crimping position of the squeeze roller 42 when the recording sheet is fed to the rotating drum 2, and the leading end positioning of the recording sheet is performed reliably and accurately. Since the peeling force due to the airflow acting on the leading edge of the recording sheet when the image is recorded on the rotated recording sheet can be suppressed, the quality of the recorded image can be reliably improved with a simple structure. Further, the deviation of the edge position of the recording sheet can be significantly reduced at low cost, and the recording speed on the recording sheet is increased by increasing the rotational speed of the rotary drum 2 without deteriorating the quality of the recorded image. In addition, the size of selectable recording sheets can be dramatically increased.

  Further, the image recording apparatus of the present embodiment can record images on a plurality of sizes of recording sheets. As shown in FIG. 4, a size selection input unit 47 is connected to the control unit 4. An edge position detection sensor 43 that detects the edge position of the recording sheet wound around the rotary drum 2 is provided on the outer periphery of the rotary drum 2.

  Then, the control unit 4 determines whether or not the size input to the size selection input unit 47 can be supplied from the magazine 5 currently set, and the size input to the size selection input unit 47 is currently set. When it is determined that the magazine 5 cannot be supplied, a display for instructing replacement of the magazine 5 is performed, and it is determined that the size input to the size selection input unit 47 can be supplied from the magazine 5 currently set. In this case, the rotary drum 2 and the squeeze roller 42 are controlled so that the squeeze roller 42 presses in the vicinity of the step 41 of the rotary drum 2.

  Next, the recording unit 6 is controlled to cut and feed the recording sheet by a predetermined length according to the input size, and when the leading end of the recording sheet reaches the step 41, the decompression pump 29 is activated. Thus, the pressure inside the rotating drum 2 is reduced, and the rotating drum 2 is rotated slowly (rotating at a remarkably slower rotational speed than when recording an image), and the squeeze roller 42 is pressed toward the rotating drum 2. Then, the recording sheet is brought into close contact with the rotating drum 2, and after rotating the rotating drum 2 once, the squeeze roller 42 is retracted.

  The pressure detector 32 detects the pressure inside the rotating drum 2 when the recording sheet is wound around the rotating drum 2.

  Then, the edge position of the recording sheet is detected by the edge position detection sensor 43. The control unit 4 is preset with an allowable range of edge positions, and the control unit 4 determines whether the edge position of the recording sheet detected by the edge position detection sensor 43 is within the preset allowable range. Judge whether or not. When the control unit 4 determines that it is out of the allowable range, the control unit 4 controls each unit so that the fed recording sheet is discharged and a new recording sheet is fed again.

  Then, the control unit 4 responds to the edge position PE of the recording sheet detected by the edge position detection sensor 43, the pressure PD in the rotary drum 2 detected by the pressure detector 32, and the input size SS. The rotational speed of the rotary drum 2 is obtained. The control unit 4 has a three-dimensional LUT in which the rotation speed of the rotary drum 2 can be obtained from the variables PE, PD, and SS. By inputting the variables PE, PD, and SS into the three-dimensional LUT, the rotary drum 2 is provided. Find the rotation speed of. Note that the LUT data of the three-dimensional LUT may be obtained by experiments.

  Then, the drum motor 27 is controlled so that the rotation speed of the rotary drum 2 becomes the calculated rotation speed of the rotary drum 2, and the light source unit of the recording head unit 1 is controlled according to the rotation speed of the rotary drum 2. 10, the light amount of the laser beam emitted from the light source unit 10, the light emission interval, and the light emission timing are controlled, and the actuator 11 is controlled according to the rotational speed of the rotary drum 2, so that the recording head unit 1 The relative moving speed in the main scanning direction MSD is controlled to record an image on a recording sheet wound around the rotary drum 2.

  When the recording of the image on the recording sheet is completed, the control unit 4 controls the rotating drum 2 to rotate slowly, stops the decompression pump 29, and discharges the recording sheet by a discharge mechanism (not shown).

  Thus, the rotational speed of the rotary drum 2 is controlled according to the input size, the edge position of the recording sheet detected by the edge position detection sensor 43, and the pressure inside the rotary drum 2 detected by the pressure detector 32. Therefore, it is possible to maintain a good balance between the suction force of the decompression pump 29 applied to the recording sheet, the centrifugal force applied to the recording sheet that changes depending on the rotation speed of the rotary drum 2, and the peeling force caused by the air current. The size of selectable recording sheets can be dramatically increased without degrading the quality of the recorded image, the allowable range of deviations in the edge position of the recording sheet is widened, and images are stably recorded on the recording sheet. Can be made.

  Next, the holes 44 and 45 and the connecting groove 46 provided in the example of the rotating drum 2 will be described with reference to FIG. 5 which is a partially developed view of the example of the rotating drum 2.

  Since the leading edge of the recording sheet is abutted against a step 41 provided on the outer peripheral surface of the rotary drum 2, the recording sheet is substantially positioned at a predetermined position according to the size. For example, the minimum size recording sheet is substantially positioned in the area A1 indicated by the one-dot chain line in FIG. 5, and the second smallest recording sheet of the second size is approximately positioned in the area A2 indicated by the one-dot chain line in FIG. The third smallest recording sheet is approximately positioned in the area A3 indicated by the two-dot chain line in FIG. 5, and the maximum recording sheet is approximately positioned in the area A4 indicated by the two-dot chain line in FIG. Is done.

  As apparent from FIG. 5, the edge position of the recording sheet when the recording sheet is wound around the rotating drum 2 (in FIG. 5, the one-dot chain line), regardless of the size of the recording sheet wound around the rotating drum 2. And the density of the holes 44 provided in the area where the recording sheet is wound near the position of the two-dot chain line) is higher than the density of the holes 45 provided in the other areas. Thereby, the suction force by the decompression pump 29 applied to the recording sheet can be increased at a low cost, the rotational speed of the rotary drum 2 can be increased, and the recording speed on the recording sheet can be increased. An allowable range for the deviation of the edge position of the recording sheet is increased, and an image can be stably recorded on the recording sheet without deteriorating the quality of the recorded image.

  In addition, a large number of connecting grooves for connecting a plurality of holes to the peripheral surface of the rotating drum 2 are provided. As apparent from FIG. 5, the edge position of the recording sheet when the recording sheet is wound around the rotating drum 2 (in FIG. 5, the one-dot chain line or the like), regardless of the size of the recording sheet wound around the rotating drum 2. There is no connecting groove straddling the position of the two-dot chain line), and the density of the connecting grooves 46 provided in other regions is high. Thereby, it is possible to suppress air leakage from the connection groove 46 at a low cost, and it is possible to increase the suction force by the decompression pump 29 applied to the recording sheet, and to increase the rotation speed of the rotary drum 2 to the recording sheet. The recording speed can be increased, the allowable range for the deviation of the edge position of the recording sheet is increased, and further, the image can be stably recorded on the recording sheet without deteriorating the quality of the recorded image. .

  Next, the holes 44 and 45 and the connecting groove 46 provided in the other example of the rotating drum 2 will be described based on FIG. 6 which is a partially developed view of another example of the rotating drum 2. The difference from the example shown in FIG. 5 is that the density of the holes 44 provided in the area where the recording sheet is wound in the vicinity of the edge position of the recording sheet in the area A1 is different from the area A2 or the area A3. The density of the hole 44 provided in the area where the recording sheet is wound near the edge position of the recording sheet in the area, and the edge of the recording sheet in the area A2 other than the area A1 or the area A3 The density of the holes 44 provided in the area where the recording sheet is wound near the position is equal to the hole provided in the area where the recording sheet is wound near the edge position of the recording sheet in the area A4 other than the area A3. The density is higher than the density of 44.

  By doing so, compared to the above example, when the recording sheet of the minimum size is wound around the rotary drum 2, the number of holes for sucking outside air that does not contribute to the adhesion of the recording sheet is small, A recording sheet of the minimum size can be more closely attached.

1 is a schematic front view of an image recording apparatus according to an embodiment. 1 is a schematic side view of an image recording apparatus according to an embodiment. FIG. 2 is a partially enlarged side view of the image recording apparatus according to the embodiment. 1 is a block diagram of an image recording apparatus according to an embodiment. FIG. 3 is a partial development view of an example of a rotating drum of the image recording apparatus according to the embodiment. FIG. 6 is a partial development view of another example of the rotating drum of the image recording apparatus according to the embodiment.

Explanation of symbols

A1 Area occupied when the recording sheet of the minimum size is wound and fixed at the normal position A2 Area occupied when the recording sheet of the second size is wound and fixed at the normal position A3 Third size of the recording sheet Area occupied when the recording sheet is wound and fixed at the regular position A4 Area occupied when the recording sheet of the maximum size is wound and fixed at the regular position CP Center point CS Convergence point MSD Main scanning direction RS recording surface SSD Sub-scanning direction 1 Recording head section 2 Rotating drum 3 Light receiving element 4 Control section 5 Magazine 6 Feeding section 10 Light source section 11 Actuator 12, 13 Axis 14 Axis holding member 20 Beam alignment optical system 21 Lens 22, 23 Mirror 24 Converging Lens Unit 25 Reduction Optical Lens Group 26 Cylindrical Lens 27 Drum Motor 28 Axis 29 Depressurization Port Pump 30 Tube 31 Holding plate 32 Pressure detector 41 Step 42 Squeeze roller 43 Edge position detection sensor 44, 45 Hole 46 Connecting groove 47 Size selection input section 61, 63 Feed roller pair 62 Cutter

Claims (8)

A hollow, a plurality of holes penetrating from the circumferential surface to the inside, a rotating drum that holds and rotates the wound recording sheet,
Decompression means for decompressing the inside of the rotating drum,
In an image recording apparatus for recording an image on a recording sheet wound around the rotating drum,
The density of the holes provided in the area where the recording sheet is wound in the vicinity of the edge position of the recording sheet when the recording sheet is wound around the rotating drum is higher than the density of the holes provided in other areas. An image recording apparatus characterized by high density. The image recording apparatus according to claim 1, wherein a connecting groove for connecting the plurality of holes is provided on a peripheral surface of the rotating drum. A hollow, a plurality of holes penetrating from the circumferential surface to the inside, a rotating drum that holds and rotates the wound recording sheet,
Decompression means for decompressing the inside of the rotating drum,
In an image recording apparatus for recording an image on a recording sheet wound around the rotating drum,
A connection groove for connecting the plurality of holes to the peripheral surface of the rotating drum is provided,
The image is characterized in that the density of the connecting groove across the edge position of the recording sheet when the recording sheet is wound around the rotating drum is lower than the density of the connecting groove provided in another region. Recording device. The image recording apparatus according to claim 3, wherein the connecting groove straddling the edge position of the recording sheet when the recording sheet is wound around the rotating drum is absent. A hollow, a plurality of holes penetrating from the circumferential surface to the inside, a rotating drum that holds and rotates the wound recording sheet,
Decompression means for decompressing the inside of the rotating drum;
A recording head unit for recording an image on a recording sheet wound around the rotating drum;
In an image recording apparatus having
An image recording apparatus, wherein the rotary drum is provided at the bottom of the apparatus, and the recording head part is provided above the rotary drum. A rotating drum that holds and rotates the wound recording sheet;
In an image recording apparatus for recording an image on a recording sheet wound around the rotating drum,
A squeeze roller that is pressed toward the rotating drum to bring the recording sheet into close contact with the rotating drum when feeding the recording sheet to the rotating drum;
An image recording apparatus, wherein a step is provided on a peripheral surface corresponding to a leading end of the recording sheet of the rotating drum. The front end of the recording sheet is abutted against the step when the recording sheet is fed to the rotating drum and the squeeze roller is pressed in the vicinity of the step of the rotating drum. 6. The image recording apparatus according to 6. The rotating drum is hollow, provided with a plurality of holes penetrating from the peripheral surface to the inside, and rotates while holding the wound recording sheet,
The image recording apparatus according to claim 6, further comprising a decompression unit that decompresses the inside of the rotary drum.

Images