JP2005266467A - Image exposure apparatus and image exposure method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image exposure apparatus capable of efficiently recording a predetermined image by exposure even in a printing original plate having no overcoat layer applied, and to provide an image exposure method. <P>SOLUTION: The image exposure apparatus is equipped with an exposure means to irradiate a printing original plate with a light beam modulated based on image signals and with a moving means to relatively move the printing original plate to the exposure means so as to two-dimensionally scan the printing original plate with the light beam, and the apparatus carries out image exposure on the printing original plate by using a light beam. The apparatus has a gas supply means to supply gas containing substantially no oxygen to the region of the printing original plate to be irradiated with the beam so as to keep the region in an atmosphere of the gas containing substantially no oxygen. The printing original plate is exposed in an atmosphere of the gas containing substantially no oxygen. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image exposure apparatus and an image exposure method for exposing a printing plate precursor in a gas atmosphere substantially free of oxygen.

  Conventionally, in printing plate precursors in which a photosensitive layer is formed on an aluminum support, a technique is generally known in which a photosensitive layer is polymerized and cured in an area exposed by laser light using a radical polymerization reaction. It has been. In this case, oxygen in the air has the property of deactivating radicals in the photosensitive layer generated by exposure, and is a factor that hinders the radical polymerization reaction in the above-described printing plate precursor. For this reason, there is a problem that the sensitivity of the printing plate precursor cannot be increased, and it is necessary to increase the intensity of the laser beam for exposure.

  As a measure for solving the above-described problems, generally, an overcoat layer is formed on a photosensitive layer formed on an aluminum support to block oxygen in the air. In order not to enter the layer, for example, refer to Patent Document 1.

  In the planographic printing plate precursor disclosed in Patent Document 1, as shown in FIG. 12, an anodized film 204 is formed on a support 202 made of aluminum, and a photosensitive layer 206 is formed on the anodized film 204. Has been. An overcoat layer 208 is provided on the photosensitive layer 206 in order to prevent polymerization inhibition due to oxygen in the air in the photosensitive layer 206 and to improve the stability of sensitivity. This overcoat layer 208 is made of polyvinyl alcohol (hereinafter also referred to as PVA) in consideration of the point that it can form a thin film with excellent oxygen barrier properties and a water-soluble polymer that can be easily removed during development. Consists of.

JP 2000-23350 A

  However, in the planographic printing plate precursor disclosed in Patent Document 1, after the exposure, in order to obtain a printing plate 210 on which a polymer layer 206a constituting a predetermined image pattern as shown in FIG. Since the overcoat layer 208 is water-soluble, there is a problem that the overcoat layer 208 dissolves into the developer in the developing machine and contaminates the water tank of the developing machine. For this reason, an image exposure apparatus and an image exposure method capable of performing predetermined exposure without providing the overcoat layer 208 are desired. However, when the overcoat layer is not provided, the printing plate precursor is increased as described above. Sensitivity cannot be achieved.

  An object of the present invention is to provide an image exposure apparatus and an image exposure method capable of solving the problems based on the prior art and efficiently recording a predetermined image by exposure even if the printing plate precursor is not provided with an overcoat layer. It is to provide.

  To achieve the above object, according to a first aspect of the present invention, there is provided an exposure means for irradiating a printing plate precursor with a light beam modulated based on an image signal, and the printing plate precursor in a two-dimensional manner by the light beam. An image exposure apparatus that has a moving means for relatively moving the exposure means and the printing plate precursor for scanning, and performs image exposure on the printing plate precursor using the light beam, A gas supply unit configured to supply a gas substantially free of oxygen to a region irradiated with the light beam in the printing plate precursor and maintain the region in a gas atmosphere substantially free of oxygen; The printing plate precursor is exposed in an atmosphere of a gas substantially free of oxygen, and an image exposure apparatus is provided.

  Moreover, in this invention, it is preferable to have further a gas collection | recovery means which collect | recovers the gas substantially not containing the said oxygen supplied to the area | region where the said light beam is irradiated by the said gas supply means.

  Furthermore, in the present invention, the apparatus may further include a circulation unit that removes oxygen from the gas recovered by the gas recovery unit and supplies the gas supply unit with a gas substantially not containing oxygen again. preferable.

  Furthermore, in the present invention, it is preferable that the gas supply means supplies the gas substantially free of oxygen to a region irradiated with the light beam so as to be in a laminar flow state.

  According to a second aspect of the present invention, a printing plate precursor is two-dimensionally scanned using a light beam modulated based on an image signal, and image exposure is performed on the printing plate precursor using the light beam. An image exposure apparatus, wherein a gas substantially free of oxygen is supplied to at least a region irradiated with the light beam in the printing plate precursor, and the region is maintained in a gas atmosphere substantially free of oxygen. And a step of performing image exposure on the printing plate precursor using the light beam in a gas atmosphere substantially free of oxygen.

According to the image exposure apparatus of the present invention, the gas supply means supplies a gas substantially free of oxygen to an area exposed in the printing plate precursor, and the vicinity of the area is changed to an atmosphere in which oxygen is substantially blocked. can do. By exposure in an atmosphere in which oxygen is substantially blocked in this way, for example, in a printing plate precursor having a photosensitive layer that undergoes a polymerization reaction by a light beam, the sensitivity of the photosensitive layer can be improved even if there is no overcoat layer. Since it is not dropped, it is possible to record an image by exposure with an intensity equivalent to the light beam intensity required for a printing plate precursor having an overcoat layer. Thus, according to the image exposure apparatus of the present invention, an image can be efficiently recorded even on a printing plate precursor having no overcoat layer.
Further, according to the image exposure apparatus of the present invention, since the printing plate precursor having no overcoat layer is exposed, the developing machine is not contaminated.

According to the image exposure method of the present invention, a step of supplying a gas substantially free of oxygen to at least a region of the printing plate precursor irradiated with a light beam, and a light beam in a gas atmosphere substantially free of oxygen For example, a printing plate precursor having a photosensitive layer that undergoes a polymerization reaction by a light beam, even if the overcoat layer is not present, the sensitivity of the photosensitive layer Therefore, it is possible to record an image by exposure with an intensity equivalent to the light beam intensity required for a printing plate precursor having an overcoat layer. As described above, according to the image exposure method of the present invention, an image can be efficiently recorded even on a printing plate precursor having no overcoat layer.
Further, according to the image exposure method of the present invention, since the printing plate precursor having no overcoat layer is exposed, the developing machine is not contaminated.

Hereinafter, an image exposure apparatus and an image exposure method of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
FIG. 1 is a schematic perspective view showing an image exposure apparatus according to the first embodiment of the present invention, and FIG. 2 is a schematic sectional side view showing the image exposure apparatus according to the first embodiment of the present invention. It is.

  The image exposure apparatus 10 of this embodiment is an outer drum type (cylindrical outer surface scanning type) plate exposure apparatus, and is a printing plate precursor that is wound and fixed around the outer surface of a cylindrical drum 30 that rotates at a constant speed. A light beam modulated based on the image signal by the lens unit that is always focused is formed on the surface of P by an autofocus mechanism provided in the exposure head 40, and the rotation direction r is determined by the rotation of the drum 30. The exposure head 40 is scanned in the sub-scanning direction M substantially parallel to the axial direction of the drum 30 while scanning in the recording direction R (main scanning direction) opposite to the recording direction R, and the surface of the printing plate precursor P is two-dimensionally irradiated with a light beam. Exposure (image recording, strictly speaking, latent image formation).

  As shown in FIG. 1, the image recording apparatus 10 basically includes a base 12, a guide rail 14, a main scanning motor (main scanning means) 22, a sub scanning motor (sub scanning means) 28, and a drum. 30, an exposure head 40 (exposure means), a controller 70, and a gas supply means.

  In the present embodiment, the gas supply means includes a blowout nozzle (hereinafter referred to as a nozzle) 82 whose tip is directed to the exposure region, a pipe 80, a gas cylinder 90 provided on the pipe 80 via a valve 92, and a pipe. And an open / close valve 94 provided at 80.

The pipe 80 is provided with a nozzle 82 at its front end, and a gas cylinder 90 is provided at its rear end via a valve 92. The pipe 80 is provided with an open / close valve 94 between the front end and the rear end.
The pipe 80 is flexible and has a sufficient length that allows the exposure head 40 to move in the sub-scanning direction M during exposure.

The nozzle 82 is disposed with its discharge port directed at the focal position of the lens unit 60, that is, at the focal position f in the printing plate precursor P and in the vicinity thereof.
The gas cylinder 90 is filled with a gas not containing oxygen. In the present invention, “substantially free of oxygen” means that the oxygen concentration is not more than a concentration that does not deactivate radicals in the photosensitive layer generated by exposure. The oxygen concentration that does not deactivate radicals is determined by the composition of the photosensitive layer.
In the present invention, the gas not containing oxygen is preferably an inert gas such as nitrogen gas, argon gas, and helium gas, or a gas such as carbon dioxide gas, from the viewpoint of safety and ease of handling.

The valve 92 is for adjusting the flow rate of the gas substantially not containing oxygen. The valve 92 is not particularly limited, and a known valve used for gas flow rate adjustment can be used.
The on-off valve 94 controls whether nitrogen gas is supplied from the nozzle 82 or not. The opening / closing valve 94 is controlled by the control unit 70 to open and close the valve.
As the on-off valve 94, for example, an electromagnetic valve (solenoid valve) may be mentioned.

  Here, in the present embodiment, nitrogen gas is preferably supplied in a laminar flow state at and near the focal position f of the light beam B. By making the focus position f and the state in the vicinity thereof laminar, exposure can be performed in a state where oxygen is blocked without involving oxygen in the atmosphere.

The base 12 is provided with a guide rail 14 on which the sub-scanning motor 28, the drum 30 and the exposure head 40 are placed.
The drum 30 has a cylindrical shape having an outer peripheral surface around which a printing plate precursor P such as a PS plate (Presensitized Plate) is wound, and the drum 30 has a fixed holding means (not shown) for fixing and holding the printing plate precursor P. Z).
The fixing and holding means has a number of suction holes provided on the surface of the drum 30 and a pressure reducing means for reducing the pressure inside the drum 30. By depressurizing the inside of the drum 30 by the decompression means, the printing plate precursor P is fixedly held on the surface of the drum 30. Note that the fixed holding means is not limited to a decompression type, and may be an electrostatic adsorption type.
The drum 30 is rotatably supported by a pair of support members 16 provided on the base 12 via bearings (not shown) on both sides of a rotating shaft (not shown). A rotary encoder 26 is provided at the end of one rotating shaft of the drum 30. The rotary encoder 26 detects the rotation angle of the drum 30, and the position of the printing plate precursor P is specified thereby.

As shown in FIG. 1, the main scanning motor 22 is a rotation driving unit that rotates the drum 30, has a rotation shaft (not shown), and is provided with a pulley 24 at an end thereof. The main scanning motor 22 constitutes a main scanning unit for the light beam B.
The drum 30 is provided with a pulley 18 at the end of the other rotating shaft. For example, the pulley 18 and the pulley 24 are connected via a winding transmission means such as a belt 20. The rotation of the main scanning motor 22 is transmitted to the drum 30 via the rotation shaft of the main scanning motor 22, the pulley 24, the belt 20, the pulley 18, and the rotation shaft of the drum 30, and the drum 30 rotates in the rotation direction r. The rotation driving means and the winding transmission means are not particularly limited to those described above, and a known rotation driving means and a winding transmission means such as a chain can be used. The main scanning motor 22 and the drum 30 are not limited to those in which power is transmitted by the winding transmission means, and may be transmission means such as a gear.

  The guide rail 14 guides the exposure head 40 in the axial direction of the drum 30 (sub-scanning direction M). The guide rails 14 are a pair of rails provided at the edge of the base 12 and extend along the axial direction of the drum 30. A ball screw 15 is provided between the guide rails 14 along the axial direction.

The sub-scanning motor 28 is a driving unit for moving the exposure head 40 in the sub-scanning direction M, and is connected to one end of the ball screw 15. The sub-scanning motor 28 constitutes a sub-scanning unit for the light beam B.
The sub-scanning motor 28 is preferably a pulse motor because it is necessary to control the amount of movement of the exposure head 40 in the sub-scanning direction M. Note that the sub-scanning motor 28 may be coupled to the ball screw 15 via the above-described transmission means, for example.
As described above, the exposure head 40 is moved in the sub-scanning direction M along the guide rail 14 by the sub-scanning motor 28.

  As shown in FIG. 2, the exposure head 40 converts light emitted from a light source 54 such as an LD or LED into parallel light by a collimator lens 56, and then converts the parallel light to a printing plate precursor P by a lens unit 52 described later. The image is formed on the surface.

  The exposure head 40 is provided with a lower base 40a, and a guide member 40b extending in the axial direction of the drum 30 is provided at a position aligned with the guide rail 14 on the lower surface of the lower base 40a. Between the guide members 40b, 40b, a guide 40c having a female screw portion that is screwed with the ball screw 15 is provided. In addition, the guide member 40b is not specifically limited, For example, what can guide in the rolling state or sliding state with the guide rail 14 is mentioned.

  Further, the exposure head 40 includes an actuator (driving means) 50 that drives the lens unit 52, a distance sensor (not shown) that measures the distance between the lens unit 52 and the surface of the printing plate precursor P, and the lens unit 52. And a lens displacement measuring sensor 60 for measuring the displacement.

  The lens unit 52 includes a lens barrel and one lens or a combination lens in which a plurality of lenses are combined, and restricts the incident light so as to have a predetermined spot diameter at the focal position.

  The distance sensor is not particularly limited, and a known distance sensor can be used. For example, a distance sensor having the same configuration as a lens displacement measurement sensor 60 described later can be used.

  The lens displacement measurement sensor 60 measures the movement amount of the lens unit 52. As the lens displacement measuring sensor 60, for example, a sensor including a reflecting plate 62 provided on the upper part of the lens unit 52 and a measuring unit 64 having a light source and a light receiving element can be cited. Based on the distance between the lens unit 52 obtained by the distance sensor and the printing plate precursor P and the amount of movement of the lens unit 52 obtained by the lens displacement measuring sensor 60, the actuator is driven by the control unit 70, and the lens unit. The distance between 52 and the surface of the printing plate precursor P is made constant. That is, the beam diameter of the light beam B on the surface of the printing plate precursor P is made constant.

  Further, in this embodiment, the present invention is not limited to image recording by one light beam emitted from one light source 54, and a plurality of light sources combining LED arrays or optical fibers and LDs as light sources are arranged. Therefore, the present invention can be suitably used for image recording using so-called multi-beam exposure, in which a plurality of recordings are simultaneously performed using a light source or the like.

  As shown in FIG. 1, the control unit 70 includes a main scanning motor 22, a sub scanning motor 28, a transport unit (not shown), an exposure head 40, an actuator 50, a valve 92, and an open / close valve 94 (see FIG. 1). 2).

The control unit 70 rotates the main scanning motor 22 at a predetermined rotation speed, and thereby the drum 30 is rotated at a predetermined rotation speed.
The control unit 70 rotates the sub-scanning motor 28 at a predetermined rotational speed, and the rotational movement of the sub-scanning motor 28 is converted into a linear movement by the ball screw 15 so that the exposure head 40 moves in the sub-scanning direction M. Moving. When the sub-scanning motor 28 is a stepping motor, the position of the exposure head 40 in the sub-scanning direction M and the scanning speed of the exposure head 40 in the sub-scanning direction M can be adjusted by controlling the rotation speed and the rotation amount. Further, the control unit 70 synchronizes the operations of the main scanning motor 22 and the sub scanning motor 28.

  The transport unit is a mechanism for supplying and discharging the printing plate precursor P, and supplies the printing plate precursor P to the drum 30 during image recording, and discharges the printing plate precursor P from the drum 30 after the image recording is completed. It is. Supply and discharge of the printing plate precursor P to the drum 30 are controlled by the control unit 70.

  The control unit 70 calculates the movement amount of the lens unit 52 based on the distance between the lens unit 52 obtained by the distance sensor and the surface of the printing plate precursor P, and moves the lens unit 52 by the actuator 50 as necessary. The distance between the exposure head 40 (lens unit 52) and the printing plate precursor P (drum 30) is always constant.

The control unit 70 controls the exposure head 40 to emit from the light source 54 a modulated light beam B necessary for image exposure created by an image signal as will be described later. The control unit 70 includes a modulation unit 57 and a driver 58 connected to the modulation unit 57.
The modulation unit 57 receives an image signal and creates a modulation signal based on the image signal.
In this embodiment, for example, when producing a printing plate, the image signal has halftone dot information for each color of C (cyan), M (magenta), Y (yellow), and K (black). The modulation unit 57 creates a modulation signal for forming a halftone image for each color. Examples of the modulation method include pulse number modulation and pulse width modulation.
The driver 58 turns on or off the light source 54 based on the modulation signal.

The controller 70 measures the position of the printing plate precursor P on the drum 30 based on the output signal of the rotary encoder 26.
For example, when an LD or LED is used as the light source 54, the control unit 70 compensates for a change in light amount due to a change in temperature.

Further, the control unit 70 adjusts the degree of opening and closing of the valve 92 to adjust the flow rate of nitrogen gas supplied from the gas cylinder 90 to the focal position f.

FIG. 3 is a schematic cross-sectional view showing the structure of a printing plate precursor used in the image exposure apparatus of this embodiment.
As shown in FIG. 3, the printing plate precursor P used in the present embodiment is different from the conventional lithographic printing plate precursor 200 shown in FIG. 12 in that the overcoat layer 208 is not provided. Since the configuration is the same as that of the lithographic printing plate precursor 200, a detailed description thereof will be omitted.

  In the present embodiment, a gas substantially free of oxygen, for example, nitrogen gas (hereinafter, nitrogen gas is a representative example) is moved from the gas cylinder 90 of the gas supply means to the focal position f of the light beam B and its vicinity. Can be supplied. For this reason, the printing plate precursor P that is not provided with the overcoat layer that acts as an oxygen blocking film can be exposed in a nitrogen gas atmosphere (hereinafter also simply referred to as nitrogen gas) that does not substantially contain oxygen. Thus, since it exposes in the state which interrupted oxygen, the radical which generate | occur | produced by exposure is not deactivated, radical polymerization reaction is not inhibited, and a sensitivity does not fall. Therefore, it is not necessary to reduce the sensitivity of the photosensitive layer. That is, the printing plate precursor P can be exposed without increasing the light intensity of the light beam to be exposed. For this reason, since it can expose without using a high output light source, apparatus cost can be reduced. Furthermore, since exposure can be performed without increasing the light intensity of the light beam to be exposed, the light source is not overused, and the life of the light source can be extended.

In the present embodiment, since it is not necessary to provide an overcoat layer on the printing plate precursor P, the developing device is not contaminated when developing after exposure.
Furthermore, in this embodiment, it is only necessary to supply nitrogen gas substantially free of oxygen to the focal position and to perform exposure in an atmosphere of nitrogen gas substantially free of oxygen, so there is no need to seal the surroundings. Since the structure can be simplified as compared with the case where oxygen is blocked by sealing the periphery, a highly reliable product can be obtained at a low cost.

  In the present embodiment, as long as the periphery of the focal position of the light beam B is filled with nitrogen gas, the present invention is not limited to the one in which nitrogen gas is locally supplied to the focal position by the nozzle 82. . For example, nitrogen gas may be supplied over the entire length of the printing plate precursor P in the sub-scanning direction M.

Next, an image exposure method using the image exposure apparatus of this embodiment will be described.
4A to 4D are schematic views showing the image exposure method of this embodiment in the order of steps. In FIG. 4, only the photosensitive layer 206 shown in FIG. 3 is illustrated, and the other configuration of the printing plate precursor P is not illustrated.

In the image exposure method of this embodiment, first, the printing plate precursor P is supplied to the drum 30 by the transport unit. Next, the inside of the drum 30 is decompressed by the fixing and holding means, and the printing plate precursor P is fixed and held on the outer peripheral surface of the drum 30.
Next, the exposure head 40 is moved to the exposure preparation position. Next, the main scanning motor 22 is driven to rotate the drum 30 at a predetermined rotational speed.

Next, after the drum 30 reaches a predetermined rotational speed and stabilizes, nitrogen gas is supplied to the focal position f and its vicinity by the gas supply means.
Next, after a predetermined time has elapsed, after the focal position f and its vicinity are filled with nitrogen gas, a modulation signal generated based on the image signal of the image to be reproduced by the modulation unit 57 is supplied to the driver 58. The driver 58 emits a modulated light beam B from the light source 54, and image exposure is performed while the exposure head 40 is conveyed in the sub-scanning direction M to form a latent image on the printing plate precursor P.

In this embodiment, in order to obtain a latent image of an image to be recorded by image exposure, the driver modulates whether the light beam B is emitted from the light source 54 or not.
However, in the present invention, the modulation of the light beam is not limited to that by the driver. For example, when the light source is a continuous wave laser, a modulator may be used to modulate the light beam and control whether the light beam is incident on the surface of the printing plate precursor. In this case, examples of the modulator include an AOM (Acousto Optic Modulator), an EOM (Electro Optic Modulator), and a spatial modulation element.

In this embodiment, autofocus control is performed, image exposure is performed to the end of the printing plate precursor P while keeping the beam spot diameter of the light beam B constant, and a latent image is formed on the printing plate precursor.
At this time, as shown in FIG. 4A, when the photosensitive layer 206 is irradiated with the light beam B, radicals 230 are generated. Next, the radical 230 causes a chain polymerization reaction, and the region irradiated with the light beam B is an ink-philic (hydrophobic) or ink-phobic (hydrophilic) polymer as shown in FIG. Region 232 is formed.

Next, after the exposure is completed, the light source 54 is turned off by the driver. Next, the supply of nitrogen gas is stopped by closing the valve 92 and the open / close valve 94. Next, the rotation of the drum 30 is stopped.
Next, after the drum 30 stops, the decompressed state by the fixed holding means is released, and the printing plate precursor P is removed from the drum 30. Next, the printing plate precursor P is unloaded by the transport unit.

  At this time, as shown in FIG. 4C, since the polymerization reaction is stopped in the photosensitive layer 206, the radical 230 is generated by the ambient light Lamb from the fluorescent lamp, for example, even in the bright room. Even so, the generated radicals 230 react with oxygen molecules m in the air that have entered the photosensitive layer 206 and are deactivated. For this reason, a latent image other than the image to be reproduced that has been image-exposed by the image exposure apparatus 10 is not formed on the printing plate precursor P.

When the time further elapses, as shown in FIG. 4D, all of the polymerization initiator in the photosensitive layer 206 is used up, radicals are not generated, and a stable state is obtained.
A printing plate can be obtained by developing the printing plate precursor P on which a latent image of an image to be reproduced is developed with a developing machine as described above. In the present embodiment, since the overcoat layer is not formed on the printing plate precursor, the developing machine is not contaminated.
In the image exposure method of the present embodiment, the nitrogen gas is supplied until the radical polymerization reaction of the image-exposed photosensitive layer 206 is stopped in order to improve the image quality of the image to be reproduced. preferable.

Next, a second embodiment of the present invention will be described.
FIG. 5 is a schematic sectional side view showing an image exposure apparatus according to the second embodiment of the present invention.
In the present embodiment, the same components as those of the image exposure apparatus 10 of the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, the image exposure apparatus 10a of the present embodiment is provided with a gas recovery means 100, a circulation means 101, and a flow rate adjustment valve 114, as compared with the image exposure apparatus 10 of the first embodiment. And the control unit 72 further controls the gas recovery means 100, the circulation means 101, and the flow rate adjustment valve 114, and other configurations are the same as those of the image exposure apparatus 10 of the first embodiment. Since it is the same, the detailed description is abbreviate | omitted.

The gas recovery means 100 recovers the nitrogen gas supplied to the focal position f and the vicinity thereof, and further ensures that the atmosphere at the focal position f and the vicinity thereof is a nitrogen gas atmosphere.
The gas recovery means 100 includes a hood 102, a dust collection filter 104, and a fan 106. The circulation unit 101 includes an oxygen separation filter (separation unit) 108 and a pump 110.

The hood 102 is a cover for sucking nitrogen gas supplied to the focal position f and the vicinity thereof. The hood 102 is provided along the outer peripheral surface of the drum 30 on the downstream side in the main scanning direction R near the focal position f, and is provided over the entire area of the drum 30 in the sub-scanning direction.
The shape of the hood 102 is not particularly limited as long as nitrogen gas can be efficiently recovered. However, in consideration of the nitrogen gas suction efficiency, it is preferable to dispose as close as possible to the focal position f and its vicinity.

  The hood 102 is not limited to the entire area of the drum 30 in the sub-scanning direction. For example, the hood 102 has the same width as the exposure head 40 in the sub-scanning direction of the drum 30. It may cooperate in the scanning direction.

  A fan 106 is provided inside the hood 102, and a dust collection filter 104 is provided on the suction port side of the fan 106. An oxygen separation filter 108 is provided on the downstream side of the suction port of the fan 106.

  The dust collection filter 104 removes dust or dust in the air, and further removes ablation gas generated during image exposure. The dust collection filter 104 is not particularly limited, and can be appropriately selected depending on the performance of the removal object or the fan 106.

  The fan 106 sucks in a gas containing nitrogen gas near the focal position f and supplies the gas to an oxygen separation filter 108 provided via a pipe 80a.

  The oxygen separation filter 108 separates oxygen gas from the gas sucked by the fan 106. An example of the oxygen separation filter 108 is one that separates into nitrogen gas and oxygen gas. In the present embodiment, nitrogen gas is separated in the gas suction direction, and oxygen gas is separated in a direction orthogonal to the suction direction. For this reason, a pipe 84 for discharging oxygen gas to the outside of the image exposure apparatus 10a is provided.

This circulating means 101 is arranged in a pipe 80a provided with a nozzle 82 at the tip.
The pump 110 supplies again the nitrogen gas separated by the oxygen separation filter 108 from the nozzle 82 provided at the tip of the pipe 80a toward the focal position f and the vicinity thereof. That is, the pump 110 circulates the nitrogen gas supplied to the focal position f and its vicinity.

  The flow rate adjusting valve 114 adjusts the flow rate of nitrogen gas supplied to the focal position f and the vicinity thereof. The flow rate adjusting valve 114 is not particularly limited, and a known valve used for gas flow rate adjustment can be used.

  A gas cylinder 90 is provided between the pump 110 and the flow rate adjustment valve 114 via the valve 112. This gas cylinder 90 is the same as that of the first embodiment, and is filled with, for example, nitrogen gas. The gas cylinder 90 serves as a supply source of nitrogen gas (a gas that does not substantially contain oxygen). The valve 112 of this embodiment can be the same as the valve 92 of the first embodiment. Also in this embodiment, the gas supply means basically includes a nozzle 82, a pipe 80 a, a gas cylinder 90, a valve 112, and an opening / closing valve 94.

  The control unit 72 is further different from the first embodiment in that it controls the operations of the fan 106 and the pump 110 and the degree of opening and closing of the flow rate adjusting valve 114, and other configurations are the same as those in the first embodiment. It is the same as that of the control part 70 (refer FIG. 1) of a form. For this reason, the detailed description about the control part 72 is abbreviate | omitted.

  In the present embodiment, the same effects as those of the image exposure apparatus of the first embodiment can be obtained. In addition, oxygen gas can be removed by the oxygen gas separation filter 108 to obtain nitrogen gas substantially free of oxygen gas. Further, the nitrogen gas substantially free of oxygen gas obtained by the separation can be supplied again from the nozzle 82 to the focal position f and the vicinity thereof by the pump 110. For this reason, useless use of nitrogen gas is eliminated.

Further, since the nitrogen gas supplied to and near the focal position f is sucked by the fan 106 of the gas recovery means 100, the focal position f and the area near the focal position f can be surely brought into a nitrogen gas atmosphere.
In the present invention, the gas is not particularly limited to nitrogen gas as long as the gas does not substantially contain oxygen. For this reason, the gas filled in the gas cylinder 90 may not be the same type as the gas separated by the oxygen separation filter 108.

  Further, in the present embodiment, the concentration of the nitrogen gas can be increased to, for example, 99% by mass or more by the oxygen separation filter 108, and such a high concentration of nitrogen gas is steadily focused until the end of exposure and the focus position f. If it can be supplied in the vicinity, the gas cylinder 90 can be dispensed with.

Furthermore, the gas recovery means 100 of the present invention may be a suction means as long as the focal position f and its vicinity can be in a nitrogen gas atmosphere.
Moreover, in this invention, although it was set as the structure which has the gas collection | recovery means 100 and the circulation means 101, this invention is not limited to this. Only the gas recovery means 100 may be provided.

Next, the image exposure method of this embodiment will be described.
Compared with the image exposure method of the first embodiment, the image exposure method of the present embodiment sucks and collects the nitrogen gas supplied to the focal position f and its vicinity by the fan 106 of the gas recovery means 100, and The oxygen gas is removed from the recovered gas, and nitrogen gas substantially not containing oxygen gas is circulated and reused by the circulation means 101. Other image exposure methods are the same as those in the first embodiment. Therefore, the detailed description thereof is omitted.

  In the present embodiment, the drum 30 is driven at a predetermined rotational speed, and then the flow rate adjusting valve is configured so that the nitrogen gas supplied from the nozzle 82 to the focal position f and its vicinity flows in a laminar flow along the drum surface. 114 is adjusted. In this case, the flow rate adjustment valve 114 is adjusted so that the linear velocity on the outer periphery of the drum 30 and the flow rate of nitrogen gas are the same. Next, the fan 106 is rotated to suck the gas at and near the focal position f, and the focal position f and the vicinity thereof are surely made into an atmosphere substantially free of oxygen.

Next, image exposure is performed with a light beam B modulated based on the image signal of the image to be reproduced in an atmosphere substantially free of oxygen at and near the focal position f, and a latent image is formed on the printing plate precursor P. Form. At this time, the nitrogen gas flowing along the drum 30 is recovered by the fan 106 of the gas recovery means 100. At this time, the dust collection filter 104 removes dust or dust generated during image exposure, ablation gas, and the like.
Next, the gas containing nitrogen gas sucked by the fan 106 is passed through the oxygen separation filter 108 to remove the oxygen gas component, and the oxygen gas is discharged from the pipe 84 to the outside.
On the other hand, the nitrogen gas obtained by passing through the oxygen separation filter 108 is transported through the pipe 80a by the pump 110, and the nitrogen gas is supplied again from the nozzle 82 to the focal position f and the vicinity thereof. Thus, the nitrogen gas from which the oxygen gas has been removed is recovered, and the nitrogen gas is reused. Such a process is repeated until after the exposure is completed.
In the image exposure method of the present embodiment, the same effect as the image exposure method of the first embodiment can be obtained also in the image exposure method of the present embodiment.

Next, a third embodiment of the present invention will be described.
FIG. 6 is a schematic sectional side view showing an image exposure apparatus according to the third embodiment of the present invention.
In the present embodiment, the same components as those in the image exposure apparatus 10a of the second embodiment shown in FIG. 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The image exposure apparatus 10b of this embodiment differs from the image exposure apparatus 10a of the second embodiment shown in FIG. 5 in that it has an oxygen concentration sensor 120, an oxygen concentration meter 122, and a warning device 124. Since this configuration is the same as that of the image exposure apparatus 10a of the second embodiment, a detailed description thereof will be omitted.

  In the image exposure apparatus 10b of this embodiment, an oxygen concentration meter 122 is connected to the oxygen concentration sensor 120. The oxygen concentration meter 122 is connected to the control unit 74. A warning device 124 is connected to the control unit 74.

The oxygen concentration sensor 120 outputs a signal corresponding to the oxygen concentration. The oxygen concentration sensor 120 is not particularly limited, and a known sensor can be used.
The oxygen concentration meter 122 displays the oxygen concentration based on the output signal of the oxygen concentration sensor 120. Further, the result of the detected oxygen concentration is output to the control unit 74.

  The warning device 124 notifies the user by display or sound when the oxygen concentration exceeds a predetermined value (oxygen concentration that does not deactivate radicals generated in the photosensitive layer). Examples of the warning device 124 include display devices using various display methods such as LCD, PDP, or CRT, speakers, and lights.

The control unit 74 turns off the light source 54 when the oxygen concentration exceeds a predetermined value based on the oxygen concentration by the oxygen concentration meter 122, as compared with the control unit 72 (see FIG. 5) of the second embodiment. Then, the exposure is stopped, and further, the warning device 124 notifies that the oxygen concentration exceeds a predetermined value by display or sound. Here, the predetermined oxygen concentration in the present embodiment refers to a concentration that deactivates radicals generated in the photosensitive layer as described above.
If the oxygen concentration exceeds a predetermined value, the controller 74 turns off the light source 54 to stop the exposure, closes the open / close valve 94, and stops the supply of nitrogen gas to the focal position f and its vicinity. May be.

  Since the image exposure apparatus 10b of this embodiment can measure the oxygen concentration, the oxygen concentration is always adjusted by adjusting the valve 112 by the control unit 74 and increasing the supply amount of nitrogen gas from the gas cylinder 90. Can be reliably maintained below a predetermined concentration. For this reason, it is possible to perform image exposure in a nitrogen gas atmosphere that does not substantially contain oxygen even more than the image exposure apparatus 10a of the second embodiment. Further, since the oxygen concentration can be managed, the amount of nitrogen gas supplied from the gas cylinder 90 can be optimized.

Next, the image exposure method of this embodiment will be described.
Compared with the image exposure method of the second embodiment, the image exposure method of the present embodiment measures nitrogen gas so as not to deactivate radicals generated in the photosensitive layer by irradiation with the light beam B while measuring the oxygen concentration. Since the other supply methods are the same as those of the second embodiment, detailed description thereof is omitted.

In the image exposure method of the present embodiment, exposure can be performed in a gas atmosphere that does not substantially contain oxygen even more than the image exposure apparatus 10a of the second embodiment. Moreover, since the oxygen concentration can be managed, the amount of nitrogen gas supplied from the gas cylinder 90 can be optimized.
In the present embodiment, it goes without saying that the same effects as those of the image exposure apparatus and the image exposure method of the second embodiment can be obtained.

Next, a fourth embodiment of the present invention will be described.
FIG. 7 is a schematic sectional side view showing an image exposure apparatus according to the fourth embodiment of the present invention.
In the present embodiment, the same components as those in the image exposure apparatus 10a of the second embodiment shown in FIG. 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

Compared with the image exposure apparatus 10a of the second embodiment shown in FIG. 5, the image exposure apparatus 10c of the present embodiment is provided with a flow rate sensor 126 in the pipe 80a in the vicinity of the nozzle 82. The difference is that it has a connected anemometer 128, and the rest of the configuration is the same as that of the image exposure apparatus 10a of the second embodiment, and a detailed description thereof will be omitted.
In the image exposure apparatus 10 c of this embodiment, the velocimeter 128 is connected to the control unit 76.

The flow rate sensor 126 outputs a signal corresponding to the flow rate of the nitrogen gas flowing in the pipe 80a. Examples of the flow rate sensor 126 include a Pitot tube and a hot-wire anemometer.
The anemometer 128 displays the flow velocity based on the output signal of the flow velocity sensor 126. Further, the result of the detected flow velocity is output to the control unit 76.

Compared with the control unit 72 (see FIG. 5) of the second embodiment, the control unit 76 causes the nitrogen gas to become a laminar flow based on the flow rate measured by the flow meter 128 (flow rate sensor 126). For example, the flow rate adjustment valve 114 is adjusted using feedback control.
In the present embodiment, the flow velocity that is a laminar flow changes depending on the rotation speed of the drum 30, and is thus calculated as appropriate according to the image exposure conditions. For example, the flow rate at which the calculated flow velocity is obtained is set as a target value, and the flow rate adjusting valve 114 is adjusted by the control unit 76.

  Since the image exposure apparatus 10c of this embodiment can measure the flow rate of the nitrogen gas to be supplied, the control unit 76 adjusts the flow rate adjusting valve 114, so that the nitrogen gas is always supplied to the focal position f and its vicinity. Can be laminar. For this reason, since entrainment of the air by a turbulent flow can be prevented, mixing of oxygen gas in the air can be suppressed. Thereby, it is possible to perform image exposure in a nitrogen gas atmosphere that does not substantially contain oxygen even more than the image exposure apparatus 10a of the second embodiment. Further, since the flow rate of the nitrogen gas is controlled so that the flow rate of the supplied nitrogen gas becomes a laminar flow, the amount of nitrogen gas supplied from the gas cylinder 90 can be optimized.

Next, the image exposure method of this embodiment will be described.
In the image exposure method of the present embodiment, the flow rate of nitrogen gas is adjusted by the control unit 74 so that the laminar flow is always obtained while measuring the flow velocity as compared with the image exposure method of the second embodiment. In other respects, the other methods are the same as those in the second embodiment, and thus detailed description thereof is omitted.

In the image exposure method of the present embodiment, nitrogen gas can be supplied to the focal position f and its vicinity so that the nitrogen gas always becomes a laminar flow, so that oxygen is further increased more than the image exposure apparatus 10a of the second embodiment. Image exposure can be performed with the modulated light beam B in a nitrogen gas atmosphere not included. Further, since the flow rate of the supplied nitrogen gas can be managed, the amount of nitrogen gas supplied from the gas cylinder 90 can be optimized.
In the present embodiment, it goes without saying that the same effects as those of the image exposure apparatus and the image exposure method of the second embodiment can be obtained.

  In the present invention, the image exposure apparatus of the fourth embodiment (see FIG. 1) or the image exposure apparatus of the fourth embodiment (see FIG. 6) is added to the image exposure apparatus of the fourth embodiment (see FIG. 1). It is good also as a structure which provides the anemometer provided in FIG.

Next, a fifth embodiment of the present invention will be described.
FIG. 8 is a schematic perspective view showing an image exposure apparatus according to the fifth embodiment of the present invention.
As shown in FIG. 8, the image exposure apparatus 130 in this embodiment is of an inner drum type. The sub-scanning direction M in the image recording apparatus 130 of the present embodiment is a direction parallel to the axial direction of the central axis of the inner drum 132.

  The image exposure apparatus 130 according to the present embodiment includes an inner drum 132 on which a printing plate precursor P on which an image or the like is recorded is mounted on a cylindrical inner peripheral surface 132a, an exposure unit (exposure means) 40a that generates a light beam L, an inner drum 132 A spinner 140 arranged concentrically with respect to the central axis of the drum 132 and scanning the light beam L with respect to the printing plate precursor P, a motor 142 for rotating the spinner 140, and a light beam emitted from the exposure unit 40a. Basically from the mirrors 144a and 144b that make L incident on the spinner 140, the baffle 134, the gas supply means, the baffle 134 and the gas supply means, and the moving means (not shown) for moving the spinner 140 and the motor 142. Composed. Also in this embodiment, the printing plate precursor P shown in FIG. 3 is used.

The baffle 134 is provided along the cylindrical inner peripheral surface 132a with a gap provided on the printing plate precursor P in order to prevent irregular reflection of the light beam E that exposes the printing plate precursor P.
The baffle 134 is formed with a rectangular opening 134a in the longitudinal direction at the center in the width direction of the belt-like plate material, and both edges of the plate material are at a predetermined angle on the opposite side of the printing plate precursor P. It is bent. The baffle 134 is formed in an arc shape along the cylindrical inner peripheral surface 132a of the inner drum 132 in the longitudinal direction.
The opening 134a of the baffle 134 is a region through which the light beam E by the spinner 140 passes.

  The spinner 140 has a reflecting surface 140a set at an inclination angle of about 45 ° with respect to the incident direction of the light beam L. The spinner 140 is connected to a motor 142 that rotates the spinner 140 about the optical axis of the light beam L. The motor 142 is connected to the control unit 78, and the rotation of the spinner 140 is controlled by the control unit 78.

Blowing nozzles (hereinafter referred to as nozzles) 136 and 138 are provided on both sides of the opening 134a of the baffle 134 in the sub-scanning direction M so that the tips thereof are directed toward the exposure position e of the printing plate precursor P. The nozzles 136 and 138 are provided over the entire length of the opening 134a.
Each nozzle 136, 138 is connected to a gas cylinder (not shown) filled with nitrogen gas via a pipe (not shown) and a valve. In the present embodiment, the gas supply means is composed of nozzles 136 and 138, piping (not shown), an open / close valve (not shown), a gas cylinder (not shown) attached via a valve (not shown), and the like. Is done.

  In addition, about the gas cylinder, the thing similar to the gas cylinder 90 (refer FIG. 1) of 1st Embodiment can be used, and the gas with which it fills can also be made the same as that of 1st Embodiment. .

The moving means moves the spinner 140 in the sub-scanning direction M together with the motor 142 in order to scan the printing plate precursor P two-dimensionally. The moving means is not particularly limited as long as it can move the spinner 140 and the motor 142 concentrically with respect to the central axis of the inner drum 132.
The light beam E reflected by the spinner 140 passes through the opening 134 a of the baffle 134. For this reason, the baffle 134 also needs to cooperate with the spinner 140. Further, since the nozzles 1346 and 138 need to supply nitrogen gas to the exposure position e, it is necessary to cooperate with the spinner 140.
As described above, in the present embodiment, driving means for moving the baffle 134 and the nozzles 1346 and 138 in the sub-scanning direction is provided. These moving means and driving means are both controlled by the controller 78, and in cooperation with the movement of the spinner 140 by the moving means, the baffle 134 and the nozzles 136, 138 are moved by the driving means. The opening 134a is moved in the sub-scanning direction M so that the light beam E passes therethrough.
Also in this embodiment, as in the first embodiment, the exposure unit 40a uses an LD as a light source. In addition, the control unit 78 includes a modulation unit and a driver as in the first embodiment.
In the present embodiment, the light beam may be modulated using the above-described modulator.

  The image exposure apparatus 130 of the present embodiment is different from the image exposure apparatus 10 of the first embodiment only in the recording form, and can obtain the same effect.

Next, the image exposure method of this embodiment will be described.
FIG. 9 is a schematic cross-sectional view for explaining an image exposure method according to the fifth embodiment of the present invention.

First, the valve is opened, and nitrogen gas filled in the gas cylinder is supplied from the nozzles 136 and 138 to the exposure position e.
Next, a modulation signal generated based on the image signal by the modulation unit is output to the driver, and a modulated light beam L necessary for image exposure is emitted from the exposure unit 40a.
The modulated light beam L is reflected by the mirrors 144 a and 114 b and is incident on the reflection surface 140 a of the spinner 140. At this time, the motor 142 is rotated at a predetermined rotation number, the spinner 140 is rotated, and the light beam L is reflected by the reflection surface 140a of the spinner 140. The reflected light beam E passes through the opening 134a of the baffle 134 and is scanned in the main scanning direction. As a result, the printing plate precursor P is image-exposed to form a latent image.

  In this case, the light beam E is scanned by the rotating spinner 140 while moving on the printing plate precursor P at high speed, while the spinner 140 and the baffle 134 cooperate with each other by the moving means and the driving means. While being moved to M, the printing plate precursor P is image-exposed with the light beam E modulated in accordance with the image signal.

Needless to say, the present embodiment can provide the same effects as those of the image exposure method of the first embodiment.
Also in this embodiment, the nitrogen gas is preferably laminar at the exposure position e of the printing plate precursor P.
Furthermore, in the present embodiment, the two nozzles 136 and 138 are provided, but the present invention is not limited to this. For example, the number of nozzles may be one as in the first embodiment.

Next, a sixth embodiment of the present invention will be described.
FIG. 10 is a schematic sectional view showing an image exposure apparatus according to the sixth embodiment of the present invention.
The same components as those of the image exposure apparatus 130 according to the fifth embodiment of the present invention shown in FIGS. 8 and 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 10, the image exposure apparatus 130a in the present embodiment has a gas supply means, a gas recovery means 100a, a circulation means 101, and a flow rate adjustment valve, as compared with the image exposure apparatus 130 of the fifth embodiment. 114, and the control unit 78a further controls the gas recovery means 100a, the circulation means 101, and the flow rate adjustment valve 114, and other configurations are the same as those of the fifth embodiment. Since it is the same as that of the image exposure apparatus 130, the detailed description is abbreviate | omitted.

Further, since the circulation means 101 and the flow rate adjustment valve 114 in this embodiment are the same as those provided in the image exposure apparatus 10a of the second embodiment, detailed description thereof will be omitted.
Furthermore, in the image exposure apparatus 130a of the present embodiment, the gas recovery unit 100a is different from the gas recovery unit 100 of the second embodiment except that the shape of the hood 102a is different from that of the second embodiment. Since it is the same as the means 100, the detailed description is abbreviate | omitted.

In the gas recovery means 100a of this embodiment, a hood 102a that is a part of the gas recovery means 100a is integrated with a baffle 135, and the hood 102a is curved along the cylindrical inner peripheral surface 132a of the inner drum 132. Yes.
Further, in the present embodiment, the tip of the nozzle 82 does not face the exposure position e from the opening 135 a but is provided along the bent portion 135 b of the baffle 135.

  In the present embodiment, since the gas recovery means 100a and the circulation means 101 are provided, the same effects as the image exposure apparatus 10a of the second embodiment can be obtained, and nitrogen gas can be used effectively. .

  The image exposure method in the present embodiment is the same as the image exposure method in the second embodiment, and a detailed description thereof will be omitted.

Needless to say, the present embodiment can provide the same effects as those of the image exposure method of the first embodiment.
Further, in the present embodiment, as in the second embodiment, it is needless to say that only the gas recovery means 100a may be provided without providing the circulation means 101.
Further, the image exposure apparatus 130 according to the fifth embodiment and the image exposure apparatus 130a according to the sixth embodiment include an oximeter of the image exposure apparatus 10a according to the third embodiment and an image exposure apparatus 10c according to the fourth embodiment. Needless to say, an anemometer is provided.

Next, a seventh embodiment of the present invention will be described.
FIG. 11 is a schematic sectional view showing an image exposure apparatus according to the seventh embodiment of the present invention.
The same components as those of the image exposure apparatus 10a according to the second embodiment of the present invention shown in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 11, the image exposure apparatus 150 in the present embodiment is of a flat bed type using a flat bed 152 on which the printing plate precursor P is placed and transported as a sub-scan transport means for the printing plate precursor P. A flat bed 152 on which the printing plate precursor P is placed is conveyed and recorded in the sub-scanning direction _Mf . The sub-scanning direction _Mf in the image recording apparatus 150 of the present embodiment is the left-right direction on the paper surface.

The image exposure apparatus 150 of this embodiment basically includes a flat bed 152 on which a printing plate precursor P on which an image or the like is recorded is placed, and a moving unit (not shown) that moves the flat bed 152 in the sub-scanning direction _Mf. And an exposure unit (exposure means) 40b for generating a light beam B and scanning the light beam B in a main scanning direction orthogonal to the sub-scanning direction _Mf , and an image forming means for printing the light beam B. The image forming apparatus includes an f-θ lens 156 that forms an image on the original plate P, a control unit 79, a gas recovery unit 100b, a circulation unit 101, and a gas supply unit. In this embodiment, for example, a polygon mirror, a galvano mirror, or a resonant scanner is used as a deflector for scanning the light beam B in the main scanning direction.

An exposure unit 40b is provided above the flat bed 152. An f-θ lens 156 is provided between the exposure unit 40 b and the flat bed 152.
In the sub-scanning direction _Mf , a nozzle 82 and a hood 102b are provided across the focal position f of the light beam B by the f-θ lens 156.
The hood 102b has an opening over the entire area of the printing plate precursor P in the main scanning direction orthogonal to the sub-scanning direction _Mf .

In the image exposure apparatus 150 of the present embodiment, the configuration of the gas recovery means 100b, the circulation means 101, and the gas supply means is the same as that of the image exposure apparatus 10a of the second embodiment, and detailed description thereof is omitted. To do.
The control unit 79 is different in that it controls the moving means of the exposure unit 40b and the flat bed 152, and is otherwise configured in the same manner as the control unit 72 of the image exposure apparatus 10a of the second embodiment. Is omitted.

Next, the image exposure method of this embodiment will be described.
In the image exposure method of the present embodiment, compared with the image exposure method of the second embodiment, the light beam B scanned in the main scanning direction by the exposure unit 40b is applied to the printing plate precursor P by the f-θ lens 156. Image exposure is performed by forming an image. At this time, the point that the flat bed 152 is intermittently conveyed in the sub-scanning direction _Mf every time the light beam B is scanned by one line is different, and the other exposure methods are the same as the image exposure method of the second embodiment. Therefore, detailed description thereof is omitted.
Also in this embodiment, image exposure can be performed in a nitrogen gas atmosphere substantially free of oxygen.
Thus, in this embodiment, the same effect as the image exposure apparatus 10a and the image exposure method of the second embodiment can be obtained.

In the image exposure apparatus 150 of the present embodiment, the gas recovery means 100b and the circulation means 101 are provided. However, the present invention is not limited to this and is the same as the first embodiment. The gas recovery means 100b and the circulation means 101 may be omitted. Moreover, it is good also as a structure which provides only the gas collection | recovery means 100b.
Furthermore, the image exposure apparatus 150 of the present embodiment may be configured to include the oxygen concentration meter of the image exposure apparatus 10a of the third embodiment and the velocimeter of the image exposure apparatus 10c of the fourth embodiment.

  The present invention is basically as described above. Although the image exposure apparatus and the image exposure method of the present invention have been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements or modifications may be made without departing from the spirit of the present invention. Of course.

1 is a schematic perspective view showing an image exposure apparatus according to a first embodiment of the present invention. It is a typical sectional side view which shows the image exposure apparatus which concerns on the 1st Embodiment of this invention. It is a typical sectional view showing the structure of the printing plate precursor used for the image exposure apparatus of this embodiment. (A)-(d) is a schematic diagram which shows the image exposure method of this embodiment in order of a process. It is a typical sectional side view which shows the image exposure apparatus which concerns on the 2nd Embodiment of this invention. It is a typical sectional side view which shows the image exposure apparatus which concerns on the 3rd Embodiment of this invention. It is a typical sectional side view which shows the image exposure apparatus which concerns on the 4th Embodiment of this invention. It is a typical perspective view which shows the image exposure apparatus which concerns on the 5th Embodiment of this invention. It is typical sectional drawing for demonstrating the image exposure method which concerns on the 5th Embodiment of this invention. It is typical sectional drawing which shows the image exposure apparatus which concerns on the 6th Embodiment of this invention. It is typical sectional drawing which shows the image exposure apparatus which concerns on the 7th Embodiment of this invention. It is typical sectional drawing which shows the conventional lithographic printing plate precursor. FIG. 5 is a schematic cross-sectional view showing a conventional lithographic printing plate precursor that has been exposed and developed.

Explanation of symbols

10, 10a, 10b, 10c, 130, 130a, 150 Image exposure apparatus 12 Base 14 Guide 16 Support member 22 Main scanning motor 26 Rotary encoder 28 Sub scanning motor 30 Drum 40 Exposure head 40a Exposure unit 50 Actuator 52 Lens unit 54 Light source 60 Displacement sensor 70, 72, 74, 76, 78, 78a, 79 Control unit 80, 80a Piping 82, 136, 138 Nozzle 90 Gas cylinder 92, 112 Valve 94 Open / close valve 100, 100a, 100b Gas recovery means 101 Circulation means 104 Collection Dust filter 106 Fan 108 Oxygen separation filter 110 Pump 114 Flow adjustment valve 132 Inner drum 134 Baffle 140 Spinner 142 Motor 152 Bed 200, P Printing plate precursor 202 Support 204 Anodized film 206 Photosensitive layer 206a Polymer layer 208 Overcoat layer 210 Printing plate 230 Radical 232 Polymer region B, L Light beam e Exposure position f Focus position Lamb Ambient light m Oxygen molecule

Claims (5)

Exposure means for irradiating a printing plate precursor with a light beam modulated based on an image signal;
Moving means for relatively moving the exposure means and the printing plate precursor in order to two-dimensionally scan the printing plate precursor with a light beam;
An image exposure apparatus that performs image exposure on the printing plate precursor using the light beam,
Gas supply means is provided for supplying a gas substantially free of oxygen to at least a region of the printing plate precursor to which the light beam is irradiated, and maintaining the region in a gas atmosphere substantially free of oxygen. And
2. The image exposure apparatus according to claim 1, wherein the printing plate precursor is exposed in a gas atmosphere substantially free of oxygen.   2. The image exposure apparatus according to claim 1, further comprising a gas recovery unit that recovers the gas substantially not containing oxygen supplied to the region irradiated with the light beam by the gas supply unit.   The image exposure apparatus according to claim 2, further comprising a circulation unit that removes oxygen from the gas collected by the gas collection unit and supplies the gas supply unit with a gas substantially free of oxygen. .   The image exposure apparatus according to claim 1, wherein the gas supply unit supplies the gas substantially free of oxygen to a region irradiated with the light beam in a laminar flow state. . An image exposure apparatus that two-dimensionally scans a printing plate precursor using a light beam modulated based on an image signal, and performs image exposure on the printing plate precursor using the light beam,
Supplying a gas substantially free of oxygen to a region irradiated with the light beam in at least the printing plate precursor, and maintaining the region in a gas atmosphere substantially free of oxygen;
And a step of performing image exposure on the printing plate precursor using the light beam in a gas atmosphere substantially free of oxygen.

Images