CN107991845B

CN107991845B - Image recording apparatus and image recording method

Info

Publication number: CN107991845B
Application number: CN201710971380.7A
Authority: CN
Inventors: 时政隆三; 藤本守; 古川典子
Original assignee: Screen Holdings Co Ltd
Current assignee: Screen Holdings Co Ltd
Priority date: 2016-10-26
Filing date: 2017-10-18
Publication date: 2020-03-10
Anticipated expiration: 2037-10-18
Also published as: JP6718793B2; CN107991845A; JP2018069485A

Abstract

The invention provides an image recording apparatus and an image recording method capable of preventing the edge of a printing plate from being arranged at a specific position when the printing plate is mounted on the outer periphery of a drum. The image recording device judges whether or not a specific state is present in which the edge of the printing plate (9) in the sub-scanning direction overlaps a specific position. Then, in the case of a specific state, the position of the printing plate (9) in the sub-scanning direction is moved by a predetermined displacement amount. This prevents the printing plate (9) from being arranged at a specific position at the end edge in the sub-scanning direction.

Description

Image recording apparatus and image recording method

Technical Field

The present invention relates to an image recording apparatus and an image recording method for recording an image on a printing plate.

Background

Conventionally, an image recording apparatus (ctp (computer to plate) apparatus) is known, which attaches a thin plate-like printing plate to the outer peripheral surface of a drum and irradiates the printing plate with a laser beam to record an image on the surface of the printing plate. A structure of a conventional image recording apparatus is described in patent document 1, for example. The image recording apparatus of patent document 1 includes a front end jig for fixing a front end edge of a printing plate to an outer peripheral surface of a drum and a rear end jig for fixing a rear end edge of the printing plate to the outer peripheral surface of the drum.

Patent document 1: japanese patent laid-open publication No. 2000-56482

In such an image recording apparatus, the rear end jig can be attached to and detached from the drum in order to cope with a plurality of printing plates having different sizes. The rear end jig can be attached to any position of the arc-shaped jig groove provided on the outer peripheral surface of the drum.

However, when the edge of the printing plate is arranged at a position just overlapping the jig groove, the vicinity of the edge of the printing plate may be lifted from the outer peripheral surface of the drum by attaching the rear end jig. Further, when the printing plate is locally raised, it is difficult to record an image on the surface of the printing plate with high accuracy.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide an image recording apparatus and an image recording method capable of preventing an edge of a printing plate from being arranged at a specific position when the printing plate is attached to an outer circumferential surface of a drum.

In order to solve the above problem, a first aspect of the present invention is an image recording apparatus for recording an image on a printing plate, comprising: the printing apparatus includes a drum having a cylindrical outer peripheral surface on which a printing plate is mounted, a rotation driving unit configured to rotate the drum about a central axis, a recording head configured to irradiate recording light onto the outer peripheral surface of the drum, a head moving mechanism configured to move the recording head in a sub-scanning direction parallel to the central axis, a positioning mechanism configured to position the printing plate in the sub-scanning direction, and a control unit configured to control the rotation driving unit, the recording head, the head moving mechanism, and the positioning mechanism. The control unit includes: an information acquiring unit that acquires offset information indicating whether or not a specific state in which an edge of the printing plate in the sub-scanning direction overlaps a specific position is present, and a first shift instructing unit that moves the position of the printing plate in the sub-scanning direction by a predetermined shift amount by the positioning mechanism when the offset information indicates the specific state.

A second invention of the present application is the image recording device according to the first invention, wherein the drum has: a jig groove provided at the specific position of the outer peripheral surface, and a jig engaged with the jig groove. An edge of the printing plate in a main scanning direction, which is a rotation direction of the drum, is fixed between the outer circumferential surface of the drum and the jig.

A third aspect of the present invention is the image recording apparatus of the first or second aspect, wherein the control unit further includes a second shift instructing unit that moves an irradiation position at which the recording light is irradiated onto the outer peripheral surface of the drum in accordance with the shift amount when the information on whether or not the shift is in the specific state is indicated.

A fourth aspect of the present invention is the image recording apparatus according to the first aspect, further comprising an input unit that receives input of the information on whether or not to shift.

A fifth aspect of the present invention is the image recording apparatus according to the first aspect, further comprising an input unit that receives an input of a type of printing plate to be processed. The control unit further includes a storage unit that stores the information on whether or not the printing plate is shifted for each type of printing plate to be processed. The information acquiring unit reads the information on whether or not to shift from the storage unit, the information on whether or not to shift corresponding to the type of printing plate input from the input unit.

A sixth aspect of the present invention is the image recording apparatus of the first aspect, further comprising an input unit that receives an input of a size of a printing plate to be processed in the sub-scanning direction. The information acquiring unit generates the information on whether or not to shift according to the size input from the input unit.

A seventh aspect of the present invention is the image recording apparatus of the first aspect, further comprising a detection unit that detects a position of an edge of the printing plate in the sub-scanning direction. The information acquisition unit generates the offset information based on the detection result output from the detection unit.

An eighth invention of the present application is the image recording apparatus of the first invention, wherein a punching unit is further provided, which forms a punch hole in the printing plate before the printing plate is mounted on the drum. The positioning mechanism positions the printing plate at a standard position before the punched hole is formed by the punching unit, and shifts a position of the printing plate in the sub-scanning direction by only the displacement amount after the punched hole is formed by the punching unit and before the printing plate is mounted to the drum.

A ninth aspect of the present invention is the image recording apparatus of the first aspect, wherein two printing plates are attached to the outer peripheral surface of the drum in the sub-scanning direction, and a plurality of the specific positions are arranged symmetrically with respect to a center of the drum in the sub-scanning direction. The first shift instructing unit moves the two printing plates in the sub-scanning direction in directions opposite to each other by the positioning mechanism.

A tenth aspect of the present invention is an image recording method for recording an image on a printing plate by attaching the printing plate to a cylindrical outer peripheral surface of a drum and irradiating recording light from a recording head moving in a sub-scanning direction parallel to a central axis of the drum while rotating the drum, the image recording method comprising: a) a step of determining whether or not a specific state is present in which the edge of the printing plate in the sub-scanning direction overlaps a specific position, and b) a step of, in the case of the specific state, shifting the position of the printing plate in the sub-scanning direction by a predetermined displacement amount.

An eleventh invention of the present application is the image recording method of the tenth invention, wherein the drum has: a jig groove provided at the specific position of the outer peripheral surface, and a jig engaged with the jig groove. The image recording method further includes a step c) of, after the step b), attaching a printing plate to the outer peripheral surface of the drum, and fixing an edge of the printing plate in a main scanning direction, which is a rotation direction of the drum, between the outer peripheral surface and the jig.

A twelfth aspect of the present invention is the image recording method according to the eleventh aspect, further comprising a step d) of irradiating the recording light from the recording head after the step c), wherein in the step d), an irradiation position of the recording light is moved in accordance with the displacement amount.

A thirteenth aspect of the present invention is the image recording method of the tenth aspect, wherein, before the step b), the method further comprises: the method includes a process of positioning a printing plate in a standard position, and a process of forming a punch hole on the printing plate positioned in the standard position.

A fourteenth aspect of the present invention is the image recording method according to the tenth aspect, wherein two printing plates are attached to the outer peripheral surface of the drum in the sub-scanning direction, and the specific positions are plural and are arranged symmetrically with respect to a center of the drum in the sub-scanning direction. The step b includes: b-1) moving one of the two printing plates in one direction in the sub-scanning direction; b-2) moving the other of the two printing plates in the other direction in the sub-scanning direction.

According to the first to ninth aspects of the present invention, when the printing plate is mounted on the outer circumferential surface of the drum, the position of the printing plate in the sub-scanning direction can be moved based on the information on whether or not the printing plate is offset. This can prevent the printing plate from being arranged at a specific position at the end edge in the sub-scanning direction.

In particular, according to the second aspect of the present invention, when the printing plate is attached to the outer circumferential surface of the drum, the end edge of the printing plate in the sub-scanning direction can be prevented from being arranged at a position overlapping the jig groove. This can prevent the printing plate from floating from the outer circumferential surface of the drum.

In particular, according to the third invention of the present application, the irradiation position of the recording light is moved in accordance with the displacement amount of the printing plate. This makes it possible to record an image at a predetermined position on the printing plate.

In particular, according to the fourth invention of the present application, the user directly inputs whether or not to offset information. Therefore, whether or not to move the position of the printing plate in the sub-scanning direction can be set according to the user's judgment.

In particular, according to the fifth invention of the present application, whether or not to move the position of the printing plate in the sub-scanning direction can be easily set according to the type of the printing plate as the processing target.

In particular, according to the sixth invention of the present application, whether or not to move the position of the printing plate in the sub-scanning direction can be automatically determined according to the size of the printing plate in the sub-scanning direction.

In particular, according to the seventh invention of the present application, it is possible to automatically determine whether or not to move the position of the printing plate in the sub-scanning direction based on the detection result output from the detection section.

In particular, according to the ninth aspect of the present invention, it is possible to avoid the edges of the two printing plates from being arranged at specific positions.

Further, according to the tenth to fourteenth inventions of the present application, when the printing plate is mounted on the outer circumferential surface of the drum, it is possible to avoid the end edge of the printing plate in the sub-scanning direction from being arranged at a specific position.

In particular, according to the eleventh aspect of the present invention, when the printing plate is attached to the outer circumferential surface of the drum, the end edge of the printing plate in the sub-scanning direction can be prevented from being arranged at a position overlapping the jig groove. This can prevent the printing plate from floating from the outer circumferential surface of the drum.

In particular, according to the twelfth invention of the present application, the irradiation position of the recording light is displaced according to the displacement amount of the printing plate. This makes it possible to record an image at a predetermined position on the printing plate.

In particular, according to the fourteenth invention of the present application, it is possible to avoid the edges of the two printing plates from being arranged at specific positions.

Drawings

Fig. 1 is a diagram showing the structure of an image recording apparatus.

Fig. 2 is a plan view of the positioning mechanism and the punching unit.

Fig. 3 is a perspective view of the drum.

Fig. 4 is a plan view of the drum and the light irradiation section.

Fig. 5 is a view showing a state in which the rear end clip is detached from the clip groove and the rear end clip is attached to the clip groove.

Fig. 6 is a block diagram showing connections of the control section and the respective sections.

Fig. 7 is a diagram conceptually showing a part of functions implemented in the control unit.

Fig. 8 is a flowchart showing the flow of operations at the time of image recording.

Fig. 9 is a diagram illustrating the state of the processing in step S3.

Fig. 10 is a diagram illustrating the state of the processing in step S6.

Fig. 11 is a diagram showing an example of an input screen of whether or not offset information is input.

Fig. 12 is a plan view of a positioning mechanism and a punching unit according to a modification.

Fig. 13 is a plan view of a drum and a light irradiation section according to a modification.

Fig. 14 is a flowchart showing an example of the detection operation of the second sensor.

Wherein the reference numerals are as follows:

1 image recording device

9 printing plate

10 conveying mechanism

11 conveyor belt

20 positioning mechanism

21a, 21b clamp pin

22-pin driving mechanism

30 punching unit

31 gap part

32 stop pin

33 punching pin

40 drum

41 peripheral surface

42 rotary driving part

43 front end clamp

44 rear end clamp

45 clamp groove

50 light irradiation part

51 recording head

52 head moving mechanism

60 operating part

61 display part

62 input part

70 control part

71 information acquisition unit

72 first Shift Command section

73 second shift instruction unit

81 first sensor

82 second sensor

91 recording surface

441 clamp bolt

P computer program

R reference information

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. Hereinafter, the rotation direction of the drum (circumferential direction along the outer circumferential surface of the drum) is referred to as "main scanning direction", and the direction parallel to the central axis of the drum is referred to as "sub-scanning direction".

1. Structure of image recording device

Fig. 1 is a diagram showing a configuration of an image recording apparatus 1 according to an embodiment of the present invention. The image recording apparatus 1 is an apparatus (CTP apparatus: direct plate making apparatus) that exposes the recording surface 91 of the printing plate 9 based on input image data and records an image on the printing plate 9. In a commercial color printing process, the image recording apparatus 1 produces a printing plate 9 corresponding to each monochrome image constituting image data. Then, the images of the printing plates 9 are superimposed on the printing paper, thereby forming a color image on the surface of the printing paper.

As shown in fig. 1, the image recording apparatus 1 of the present embodiment includes a conveying mechanism 10, a positioning mechanism 20, a punching unit 30, a drum 40, a light irradiation unit 50, an operation unit 60, and a control unit 70.

The conveying mechanism 10 is a mechanism that conveys the printing plate 9 before exposure. For example, the printing plate 9 is a rectangular metal plate, and a photosensitive material is coated in advance on a recording surface 91 which is one surface of the metal plate. The printing plate 9 is set at a predetermined conveyance start position in the image recording apparatus 1 by an automatic feeding apparatus or a user. The conveying mechanism 10 conveys the printing plate 9 set at the conveyance start position by rotating the conveyor belt 11.

The conveying mechanism 10 is configured to be capable of changing the position and inclination of the conveyor belt 11 between a punching facing position P1 indicated by a solid line in fig. 1 and a drum facing position P2 indicated by a two-dot chain line in fig. 1 by a swing mechanism, not shown. When the conveyor belt 11 is disposed at the punch facing position P1 and the conveyor belt 11 is rotated in the forward direction, the printing plate 9 is fed to the punch unit 30. Further, in this state, when the conveyor belt 11 is rotated in the reverse direction, the printing plate 9 can be pulled back from the punching unit 30. Further, when the conveyor belt 11 is disposed at the drum opposing position P2 and the conveyor belt 11 is rotated in the normal direction, the printing plate 9 is fed to the drum 40.

The positioning mechanism 20 is a mechanism that positions the position of the printing plate 9 in the sub-scanning direction at a desired position. The positioning mechanism 20 has a function of positioning the printing plate 9 at a standard position in the sub-scanning direction, and a function of moving the position of the printing plate 9 in the sub-scanning direction away from the standard position as necessary. Fig. 2 is a plan view of the positioning mechanism 20 and the punching unit 30. As shown in fig. 2, the positioning mechanism 20 has a pair of

clamp pins

21a, 21b and a pin driving mechanism 22. The pin drive mechanism 22 moves the pair of

clamp pins

21a, 21b individually in the sub-scanning direction. For the pin drive mechanism 22, for example, a mechanism is used which converts the rotational motion of a servomotor into a linear forward motion via a ball screw. The positioning mechanism 20 positions the position of the printing plate 9 in the sub-scanning direction at a desired position by pushing both side edge portions of the printing plate 9 in the sub-scanning direction with a pair of

clamp pins

21a, 21 b.

Punch unit 30 is a unit that forms punches in printing plate 9 before mounting printing plate 9 on drum 40. As shown in fig. 1, the punching unit 30 has a gap portion 31 into which the leading edge (edge on the downstream side in the conveying direction) of the printing plate 9 is inserted. As shown in fig. 1 and 2, the punching unit 30 includes a pair of stop pins 32 provided in the gap portion 31 and a plurality of punching pins 33 for forming a punching hole in the printing plate 9.

The front end edge of the printing plate 9 inserted into the gap portion 31 contacts a pair of stop pins 32. Thereby, the position of the printing plate 9 in the conveying direction is positioned at a predetermined position. The pair of punch pins 33 are moved up and down by a drive mechanism, not shown, and pierce a part of the front edge of the printing plate 9. Thereby, a punched hole is formed at a predetermined position of the leading edge of the printing plate 9.

The punched holes formed in the printing plate 9 are used for positioning the printing plate 9 in a printing apparatus using the exposed and developed printing plate 9. Thus, the printing plates 9 of the respective colors are positioned with high accuracy in the printing apparatus. As a result, the problem of positional deviation of images of respective colors from each other in the printed matter output from the printing apparatus can be suppressed.

The drum 40 is a rotary body disposed below the punching unit 30. The drum 40 has a cylindrical outer peripheral surface 41 extending in the sub-scanning direction. As shown by the broken line in fig. 1, the drum 40 is connected to a rotary drive section 42. The rotation driving unit 42 is composed of, for example, a motor and a power transmission mechanism such as a timing belt (timing belt) for transmitting a driving force of the motor to the drum 40. When the rotation driving unit 42 is operated, the drum 40 rotates about a central axis extending in the sub-scanning direction.

Fig. 3 is a perspective view of the drum 40. Fig. 4 is a plan view of the drum 40 and the light irradiation section 50. As shown in fig. 1, 3, and 4, a plurality of leading end jigs 43 and a plurality of trailing end jigs 44 are provided on the outer circumferential surface 41 of the drum 40. The plurality of front end clamps 43 fix the front end edges of the printing plates 9 conveyed from the conveying mechanism 10 to the outer peripheral surface 41 of the drum 40. The plurality of rear end clamps 44 fix the rear end edge (the edge on the upstream side in the conveying direction) of the printing plate 9 to the outer peripheral surface 41 of the drum 40. Thereby, the printing plate 9 is attached to the outer peripheral surface 41 of the drum 40 with the recording surface 91 facing outward.

As shown in fig. 3 and 4, a plurality of jig grooves 45 are provided on the outer circumferential surface 41 of the drum 40. At a specific position in the sub-scanning direction, each of the jig grooves 45 extends in the main scanning direction. The rear end gripper 44 can be attached or detached at any position in the main scanning direction of the gripper groove 45.

Fig. 5 is a view showing a state in which the rear end jig 44 is detached from the jig groove 45 and the rear end jig 44 is attached to the jig groove 45. As shown in fig. 5, the rear end clamp 44 has a T-shaped clamp bolt 441. When the rear end jig 44 is fixed to the outer circumferential surface 41 of the drum 40, the jig bolt 441 of the rear end jig 44 is inserted into the jig groove 45, and the jig bolt 441 is rotated. Thereby, the jig bolt 441 engages with the jig groove 45. The rear end edge of the printing plate 9 is held between the outer peripheral surface 41 of the drum 40 and the rear end jig 44.

The light irradiation unit 50 is a unit that irradiates the outer peripheral surface 41 of the drum 40 with recording light. The light irradiation unit 50 includes a recording head 51 that emits recording light such as laser light, and a head moving mechanism 52 that moves the recording head 51 in the sub-scanning direction. When recording an image on the printing plate 9, the recording head 51 is moved in the sub-scanning direction by the head moving mechanism 52 while rotating the drum 40 on which the printing plate 9 is mounted, and laser light is irradiated from the recording head 51 to the recording surface 91 of the printing plate 9. Thereby, an exposure area according to a monochrome image is formed on the recording surface 91 of the printing plate 9.

The exposed printing plate 9 is carried out from the drum 40 to a predetermined carrying-out position in the image recording apparatus 1 by a carrying-out mechanism not shown.

The operation unit 60 is a part serving as a user interface. The operation unit 60 includes a display unit 61 and an input unit 62. The display section 61 displays various information related to the processing of the image recording apparatus 1 on a screen. A liquid crystal display, for example, is used as the display section 61. The input section 62 receives input of various information from the user. The input section 62 uses, for example, a keyboard or a mouse. The user of the image recording apparatus 1 can input various information to the control unit 70 by operating the input unit 62 while checking the display unit 61.

In addition, both the function of the display unit 61 and the function of the input unit 62 may be realized by a single device such as a touch panel display.

The control unit 70 is a method for controlling the operation of each unit in the image recording apparatus 1. Fig. 6 is a block diagram showing the connection of the control unit 70 to each unit in the image recording apparatus 1. As conceptually shown in fig. 6, the control Unit 70 is configured by a computer having a processor 701 such as a CPU (Central processing Unit), a Memory 702 such as a RAM (Random Access Memory), and a storage Unit 703 such as a hard disk drive. The storage unit 703 is provided with a computer program P for executing each process implemented in the image recording apparatus 1 and reference information R described later.

As shown in fig. 6, the control unit 70 is electrically connected to the conveyance mechanism 10, the pin drive mechanism 22, the punching unit 30, the rotation drive unit 42, the front end gripper 43, the rear end gripper 44, the recording head 51, the head movement mechanism 52, and the operation unit 60. The control unit 70 temporarily reads the computer program P stored in the storage unit 703 to the memory 702, and the processor 701 performs arithmetic processing based on the computer program P to control the operations of the above-described respective units. This allows the printing plate 9 to be conveyed, positioned in the sub-scanning direction, punched, and recorded with an image, in this order.

Fig. 7 is a diagram conceptually showing a part of the functions implemented in the control section 70. As shown in fig. 7, the control unit 70 includes an information acquisition unit 71, a first shift instruction unit 72, and a second shift instruction unit 73. The control section 70 realizes, by these respective sections, processing for avoiding the end edge of the printing plate 9 mounted on the drum 40 in the sub-scanning direction from overlapping the jig groove 45. The specific processing performed by the information acquisition unit 71, the first shift instructing unit 72, and the second shift instructing unit 73 will be described later.

2. Regarding the action during image recording

Next, an operation when an image is recorded on the printing plate 9 in the image recording apparatus 1 will be described. Fig. 8 is a flowchart showing the flow of operations at the time of image recording.

When an image is recorded on the printing plate 9, first, the type of the printing plate 9 to be processed is input (step S1). Specifically, the user inputs the type of printing plate 9 to control unit 70 by operating input unit 62. The memory 703 in the control unit 70 stores reference information R unique to each type of printing plate 9 in advance. The reference information R includes the size of the printing plate 9, the processing conditions for the printing plate 9, and the like. In the present embodiment, whether or not offset information described later is also stored as one piece of reference information R in the storage unit 703. The control unit 70 can read out the information from the storage unit 703 according to the type of the printing plate 9 input from the input unit 62.

When the input of the kind of printing plate 9 is completed, the automatic feeding apparatus or the user sets the printing plate 9 to the image recording apparatus 1. The user inputs an instruction to start the operation through the operation input unit 62. In this way, the image recording apparatus 1 starts carrying in the printing plate 9 by the carrying mechanism 10.

First, the conveying mechanism 10 arranges the conveyor belt 11 at the punch hole facing position P1. Then, by rotating the conveyor belt 11 in the forward direction, the printing plate 9 is conveyed toward the punching unit 30 (step S2). The front edge of printing plate 9 passes between the pair of clamp pins 21a and 21b of positioning mechanism 20 and is inserted into gap 31 of punching unit 30. When the leading edge of the printing plate 9 comes into contact with the stop pin 32, the conveying mechanism 10 immediately stops the rotation of the conveyor belt 11.

Next, the positioning mechanism 20 positions the position of the printing plate 9 in the sub-scanning direction at the standard position (step S3). Fig. 9 is a diagram showing the positioning in step S3.

As shown in fig. 9, first, the positioning mechanism 20 operates the pin driving mechanism 22 to bring one holding pin 21a into contact with one end edge of the printing plate 9 in the sub-scanning direction. Next, the printing plate 9 is pushed by the clamp pin 21a, and the printing plate 9 is moved to the other side in the sub-scanning direction (see the first drawing from the top in fig. 9). At this time, the printing plate 9 is temporarily moved to a position further to the other side in the sub-scanning direction than the standard position C shown by the one-dot chain line in fig. 9.

Next, the positioning mechanism 20 separates one clamp pin 21a from the printing plate 9, and brings the other clamp pin 21b into contact with the other end edge of the printing plate 9 in the sub-scanning direction. Next, the printing plate 9 is pushed by the clamp pin 21b, and the printing plate 9 is moved to one side in the sub-scanning direction. The clamp pin 21b moves to one side in the sub-scanning direction until the position of the printing plate 9 in the sub-scanning direction coincides with the standard position C. Thereby, the position of the printing plate 9 in the sub-scanning direction is positioned at the standard position C (refer to the second from the top of fig. 9).

When the position of the printing plate 9 in the sub-scanning direction is positioned at the standard position C, the positioning mechanism 20 moves one clamp pin 21a to the other side in the sub-scanning direction (see the third from the top in fig. 9). Then, one holding pin 21a is brought into contact with one end edge of the printing plate 9 in the sub-scanning direction again. Thereby, the position of the printing plate 9 is fixed (see the fourth from the top of fig. 9). In this state, the punching unit 30 moves the pair of punching pins 33 up and down. Thus, a part of the leading edge of the printing plate 9 is punched through. As a result, a punched hole is formed at a predetermined position of the leading edge of the printing plate 9 (step S4).

Next, the control section 70 determines whether or not a specific state is present in which the end edge of the printing plate 9 in the sub-scanning direction overlaps the position of the jig groove 45 in the sub-scanning direction (step S5). Specifically, the information acquiring unit 71 of the control unit 70 reads the reference information R corresponding to the type of printing plate 9 input in step S1 from the storage unit 703. In this way, the information acquiring unit 71 acquires the preset offset information as one of the reference information R. The information on whether or not the offset is present indicates whether or not the printing plate 9 disposed at the standard position C is in a specific state in which the edge in the sub-scanning direction overlaps the jig groove 45. The control section 70 identifies whether or not a specific state is present in which at least one end edge of the printing plate 9 in the sub-scanning direction overlaps with the position of the jig groove 45 in the sub-scanning direction, by referring to the information on whether or not the deviation is present.

When it is determined in step S5 that the printing plate is in the specific state, the first shift instructing unit 72 of the control unit 70 controls the positioning mechanism 20 to move the position of the printing plate 9 in the sub-scanning direction (step S6). Fig. 10 is a diagram illustrating the state of the processing in step S6.

In step S6, a control signal is transmitted from the first shift instructing unit 72 to the positioning mechanism 20. Thus, first, the pair of clamp pins 21a and 21b of the positioning mechanism 20 are separated from both end edges of the printing plate 9 in the sub-scanning direction (see the first upper drawing of fig. 10). Thereby, the fixing of the printing plate 9 is released. Next, either one of the pair of

clamp pins

21a, 21b (clamp pin 21a in the example of fig. 10) pushes the end edge of printing plate 9 in the sub-scanning direction (see the second from the top in fig. 10). Thereby, the position of the printing plate 9 in the sub-scanning direction is moved by a predetermined displacement amount. As a result, the end edge of the printing plate 9 in the sub-scanning direction becomes not in a specific state of overlapping the position of the jig groove 45 in the sub-scanning direction. When the movement of the printing plate 9 in the sub-scanning direction is completed, the pair of holding

pins

21a, 21b are separated from both end edges of the printing plate 9 in the sub-scanning direction (see the third from the top in fig. 10).

For example, the displacement amount of the printing plate 9 may be stored in the storage unit 703 as one of the reference information R. Further, it is preferable that the displacement amount of the printing plate 9 is smaller than the interval of the adjacent jig grooves 45 in the sub-scanning direction.

On the other hand, in step S5, when it is determined that the specific state is not present, the first displacement instructing unit 72 of the control unit 70 does not operate the positioning mechanism 20. That is, the process of step S6 of moving the position of the printing plate 9 in the sub-scanning direction is not performed.

When it is determined in step S5 that the conveyance mechanism 10 is in the unspecified state or step S6 is completed, the control unit 70 operates the conveyance mechanism 10 again. Thereby, printing plate 9 is pulled out from punching unit 30, and printing plate 9 is mounted on drum 40 (step S7).

In step S7, first, the conveyance mechanism 10 rotates the conveyor belt 11 in the reverse direction. Thereby, the front edge of printing plate 9 is pulled out from gap portion 31 of punching unit 30. Then, the entire printing plate 9 is disposed again on the conveyor belt 11. Subsequently, the conveying mechanism 10 switches the position of the conveyor belt 11 from the punch facing position P1 to the drum facing position P2. Then, the conveying mechanism 10 rotates the conveyor belt 11 in the forward direction. Thereby, the leading edge of the printing plate 9 is supplied to the drum 40.

The leading edge of the printing plate 9 fed to the drum 40 is brought into contact with a plurality of leading edge jigs 43. Thereby, printing plate 9 stops. When printing plate 9 stops, control section 70 closes the plurality of leading-end clamps 43. The leading edge of the printing plate 9 is thereby fixed between the outer peripheral surface 41 of the drum 40 and the leading edge clamp 43. Then, the control unit 70 rotates the drum 40, and transfers the printing plate 9 from the conveying mechanism 10 to the drum 40. After the entire printing plate 9 is disposed on the outer circumferential surface 41 of the drum 40, the plurality of rear end clamps 44 are closed, and the rear end edge of the printing plate 9 is fixed between the outer circumferential surface 41 of the drum 40 and the rear end clamps 44. As a result, printing plate 9 is mounted on outer circumferential surface 41 of drum 40.

When printing plate 9 is mounted on outer circumferential surface 41 of drum 40, control unit 70 operates head moving mechanism 52. Thereby, the recording head 51 is moved in the sub-scanning direction to a position opposite to the recording start position of the printing plate 9 (step S8). Here, in step S6 described above, when the printing plate 9 is moved in the sub-scanning direction, the second shift instructing unit 73 of the control unit 70 moves the position of the target of movement of the recording head 51 in accordance with the amount of displacement in step S6. Thereby, even when step S6 is executed, the recording head 51 can be accurately moved to the recording start position of the printing plate 9.

Then, the control unit 70 operates the rotation driving unit 42, the head moving mechanism 52, and the recording head 51. Thereby, while rotating the drum 40 and moving the recording head 51 in the sub-scanning direction, the recording light is irradiated from the recording head 51 to the printing plate 9. Thereby, an image is recorded on the recording surface 91 of the printing plate 9 (step S9).

In the present embodiment, step S6 described above is executed as necessary. Therefore, when the printing plate 9 is attached to the outer peripheral surface 41 of the drum 40, the clamp groove 45 can be prevented from overlapping with both end edges of the printing plate 9 in the sub-scanning direction. Therefore, local floating of printing plate 9 from outer circumferential surface 41 of drum 40 in the vicinity of the end edge in the sub-scanning direction due to the influence of jig groove 45 can be suppressed. That is, the printing plate 9 can be firmly brought into contact with the outer peripheral surface 41 of the drum 40 in the vicinity of the end edge in the sub-scanning direction. As a result, in step S9, the image can be recorded on recording surface 91 of printing plate 9 with high accuracy.

In particular, in the image recording apparatus 1, whether or not offset information is set in advance for each type of printing plate 9 to be processed. Therefore, when the user inputs the kind of the printing plate 9, the image recording apparatus 1 can automatically recognize whether the process of step S6 should be executed. Therefore, the process of step S6 can be appropriately performed on printing plate 9 that requires the process of step S6.

In step S8, the image recording apparatus 1 moves the position of the target of movement of the recording head 51 in accordance with the displacement amount in step S6. Thereby, the irradiation position of the recording light on the outer peripheral surface 41 of the drum 40 is moved in accordance with the displacement amount of step S6. Therefore, even when the process of step S6 is executed, the image can be recorded at a predetermined position on the printing plate 9 with high accuracy.

3. Modification example

While the main embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. Hereinafter, various modifications will be described mainly in differences from the above-described embodiment.

3-1. first modification

In the above-described embodiment, the storage unit 703 in the control unit 70 stores information on whether or not to shift as one of the reference information R, and executes the movement of the printing plate 9 in the sub-scanning direction in accordance with the information. However, it is also possible that the user inputs whether or not to perform the movement of the printing plate 9 in the sub-scanning direction by operating, for example, the input section 62 each time the image recording process is performed on the printing plate 9. Fig. 11 is a diagram showing an example of an input screen that selects whether to perform movement of the printing plate 9 in the sub-scanning direction. As shown in fig. 11, it is only necessary to select whether or not to perform the movement of the printing plate 9 in the sub-scanning direction from two options of "ON" (ON: perform movement) and "OFF" (OFF: not perform movement). Accordingly, control unit 70 only needs to execute the movement of printing plate 9 in the sub-scanning direction when the input is "ON". In this way, if it is set that the user can directly input whether or not to move the printing plate 9, the user can randomly select whether or not to execute the processing of step S6.

3-2. second modification

Further, the user can input the size of the printing plate 9 as a processing target in the sub-scanning direction from the input section 62. In this case, the information acquisition unit 71 of the control unit 70 automatically determines whether or not a specific state in which the edge of the printing plate 9 in the sub-scanning direction overlaps the jig groove 45 is present by arithmetic processing based on the dimension input from the input unit 62. That is, the information acquiring unit 71 generates the offset information based on the size input from the input unit 62. Thus, it is not necessary to separately input the size of the printing plate 9 and the information on whether or not to shift. Therefore, the input load of the user can be reduced.

3-3. third modification

Fig. 12 is a plan view of the positioning mechanism 20 and the punching unit 30 of the image recording apparatus 1 according to the third modification. The image recording apparatus 1 of the example of fig. 12 has a pair of first sensors 81. The first sensor 81 is a detection unit that detects the position of the printing plate 9, the leading edge of which is inserted into the punching unit 30, in the sub-scanning direction. As the first sensor 81, a non-contact sensor such as an optical sensor is used. The first sensor 81 detects the presence or absence of light shielding at each position by moving along the sub-scanning direction, thereby detecting the position of the edge of the printing plate 9 in the sub-scanning direction. The detection result is transmitted from the first sensor 81 to the control unit 70.

The information acquisition unit 71 of the control unit 70 determines whether or not a specific state is present in which the end edge of the printing plate 9 in the sub-scanning direction overlaps the position of the jig groove 45 in the sub-scanning direction, based on the detection result output from the first sensor 81. That is, the information acquisition unit 71 generates whether or not to shift information based on the detection result output from the first sensor 81. In this way, it is possible to accurately acquire whether or not the offset information is based on the measured value. Further, the user does not have to input the size of the printing plate 9 in the sub-scanning direction or whether to shift information.

In the example of fig. 12, the clamp pin 21 and the first sensor 81 are integrally attached to the moving element of the pin driving mechanism 22 of the positioning mechanism 20. Therefore, the first sensor 81 can be moved in the sub-scanning direction by the pin driving mechanism 22. In this way, it is not necessary to provide a moving mechanism inherent to the first sensor 81, except for the pin driving mechanism 22. Therefore, the number of components constituting the image recording apparatus 1 can be reduced.

3-4. fourth modification

Fig. 13 is a plan view of the drum 40 and the light irradiation section 50 of the image recording apparatus 1 according to the fourth modification. The image recording apparatus 1 of the example of fig. 13 has a second sensor 82. The second sensor 82 is a detection portion that detects the position of the printing plate 9 attached to the outer circumferential surface 41 of the drum 40 in the sub-scanning direction. As the second sensor 82, a non-contact sensor such as an optical sensor is used. The second sensor 82 detects a change in the reflection state of light at each position by moving along the sub-scanning direction, thereby detecting the position of the edge of the printing plate 9 in the sub-scanning direction. The detection result is sent from the second sensor 82 to the control unit 70.

The control section 70 identifies a recording start position at which an image is recorded on the printing plate 9 mounted on the drum 40, based on the detection result output from the second sensor 82. In this way, the recording start position at which an image is recorded on the printing plate 9 attached to the drum 40 can be identified more accurately based on the measured value.

In the example of fig. 13, the recording head 51 and the second sensor 82 are integrally attached to the moving element of the head moving mechanism 52. Therefore, the second sensor 82 can be moved in the sub-scanning direction by the head moving mechanism 52. In this way, it is not necessary to provide a unique moving mechanism in the second sensor 82 in addition to the head moving mechanism 52. Therefore, the number of components constituting the image recording apparatus 1 can be reduced.

Fig. 14 is a flowchart showing an example of the detection operation of the second sensor 82. When printing plate 9 is mounted on outer circumferential surface 41 of drum 40, control unit 70 operates head moving mechanism 52. Thereby, the second sensor 82 is arranged in the vicinity of the end edge of the printing plate 9 in the sub-scanning direction (step S11). Then, while the second sensor 82 is moved slowly in the sub-scanning direction, the position of the end edge of the printing plate 9 in the sub-scanning direction is detected (step S12).

In step S11, the second sensor 82 is moved at a speed higher than that in step S12. By moving the second sensor 82 to the vicinity of the target position at high speed in this manner, the time for detecting the position of the printing plate 9 in the sub-scanning direction can be reduced. In particular, in step S6 described above, when the position of printing plate 9 in the sub-scanning direction is moved, control unit 70 calculates the position of printing plate 9 after the movement in the sub-scanning direction. Then, in step S11, the second sensor 82 is disposed in the vicinity of the end edge of the printing plate 9 after the movement in the sub-scanning direction. That is, the second sensor 82 is moved in consideration of the movement of the printing plate 9. Thereby, the second sensor 82 can be moved to the vicinity of the target position more quickly and accurately.

In the case of having both the first sensor 81 and the second sensor 82 described above, it is preferable that the first sensor 81 and the second sensor 82 detect the same position of the printing plate 9 in the main scanning direction. In this manner, in step S12, the second sensor 82 can be moved more accurately in consideration of the detection result of the first sensor 81.

3-5. fifth modification

In the above-described embodiment, the image recording apparatus 1 processes the printing plates 9 one by one. However, in the image recording apparatus 1, the number of printing plates 9 to be processed simultaneously may be two. For example, two printing plates 9 may be attached in parallel in the sub-scanning direction on the outer circumferential surface 41 of the drum 40.

In this case, the plurality of jig grooves 45 of the drum 40 and the two printing plates 9 are arranged symmetrically with respect to the center in the sub-scanning direction of the drum 40. Therefore, when the process of step S6 is performed, it is preferable that the two printing plates 9 are moved in the directions opposite to each other in the sub-scanning direction. That is, one of the two printing plates 9 is moved by a predetermined displacement amount in one direction in the sub-scanning direction, and then the other of the two printing plates 9 is moved by a predetermined displacement amount in the other direction in the sub-scanning direction. This can prevent the end edges of the two printing plates 9 in the sub-scanning direction from overlapping the jig groove 45.

In the image recording apparatus 1, the number of printing plates 9 to be processed simultaneously may be three or more.

3-6. others

In the above-described embodiment, the case where the end edge of the printing plate 9 in the sub-scanning direction is prevented from overlapping the jig groove 45 for fixing the rear end jig 44 has been described. That is, the description has been made regarding the case where the "specific position" in the present invention is the position of the jig groove 45. However, a recess or a hole other than the jig groove may be provided on the outer circumferential surface of the drum. The "specific position" in the present invention may be a position of a recess or a hole other than the jig groove in the sub-scanning direction.

Further, the configuration of the details of the image recording apparatus may be different from those of the drawings of the present application. In addition, the respective elements appearing in the above-described embodiments or modified examples may be appropriately combined within a range in which no contradiction occurs.

Claims

1. An image recording apparatus for recording an image on a printing plate, comprising:

a drum having a cylindrical outer peripheral surface on which the printing plate is mounted,

a rotation driving unit configured to rotate the drum around a central axis,

a recording head for irradiating the outer peripheral surface of the drum with recording light,

a head moving mechanism that moves the recording head in a sub-scanning direction parallel to the central axis,

a positioning mechanism that positions the printing plate in the sub-scanning direction by pushing an end edge of the printing plate orthogonal to the sub-scanning direction, and

a control unit that controls the rotation driving unit, the recording head, the head moving mechanism, and the positioning mechanism;

grooves, recesses or holes are provided on the outer circumferential surface of the drum,

the control unit includes:

an information acquisition unit that acquires offset information indicating whether or not a specific state is present in which an edge of the printing plate in the sub-scanning direction overlaps a specific position in which the groove, the recess, or the hole is provided, and

a first shift instruction section; the position of the printing plate in the sub-scanning direction is shifted by a predetermined displacement

When the control unit determines that the printing plate is in the specific state based on the information on whether or not the printing plate is shifted, the first shift instructing unit controls the positioning mechanism to move the position of the printing plate in the sub-scanning direction by a predetermined shift amount,

the first shift instructing section does not execute the movement of the position of the printing plate in the sub-scanning direction when the control section determines that the printing plate is not in the specific state based on the information on whether or not the printing plate is shifted.

2. The image recording apparatus according to claim 1,

the drum has:

a jig groove as the groove, and

the clamp is clamped in the clamp groove;

an end edge of the printing plate in a main scanning direction, which is a rotation direction of the drum, is fixed between the outer circumferential surface of the drum and the jig.

3. The image recording apparatus according to claim 1 or 2,

the control unit further includes a second shift instructing unit that moves an irradiation position at which the recording light is irradiated onto the outer peripheral surface of the drum in accordance with the displacement amount when the presence/absence of the shift information indicates that the specific state is present.

4. The image recording apparatus according to claim 1,

the device further comprises an input unit for receiving the input of the information on whether to shift.

5. The image recording apparatus according to claim 1,

further comprises an input unit for receiving an input of a type of printing plate to be processed,

the control unit further includes a storage unit that stores the information on whether or not the printing plate is shifted for each type of printing plate to be processed,

the information acquiring unit reads the information on whether or not to shift from the storage unit, the information on whether or not to shift corresponding to the type of printing plate input from the input unit.

6. The image recording apparatus according to claim 1,

further having an input section that receives an input of a size of a printing plate as a processing object in the sub-scanning direction,

the information acquiring unit generates the information on whether or not to shift according to the size input from the input unit.

7. The image recording apparatus according to claim 1,

further comprising a detection unit that detects a position of an edge of the printing plate in the sub-scanning direction,

the information acquisition unit generates the offset information based on the detection result output from the detection unit.

8. The image recording apparatus according to claim 1,

also having a punch unit that forms a punch in the printing plate prior to mounting the printing plate to the drum;

the positioning mechanism positions the printing plate at a standard position before the punch unit forms the punch, and moves the position of the printing plate in the sub-scanning direction by only the displacement amount after the punch unit forms the punch and before the printing plate is mounted to the drum.

9. The image recording apparatus according to claim 1,

mounting two printing plates on the outer circumferential surface of the drum in the sub-scanning direction,

the specific position is present in plural and is arranged symmetrically with respect to the center of the sub-scanning direction of the drum,

the first shift instructing unit moves the two printing plates in the sub-scanning direction in directions opposite to each other by the positioning mechanism.

10. An image recording method for mounting a printing plate on a cylindrical outer peripheral surface of a drum provided with a groove, a recess, or a hole, and recording an image on the printing plate by irradiating recording light from a recording head moving in a sub-scanning direction parallel to a central axis of the drum while rotating the drum,

the image recording method includes:

a) a step of judging whether or not a printing plate is in a specific state in which an edge of the printing plate in the sub-scanning direction overlaps a specific position where the groove, the recess, or the hole is provided, and

b) and a step of, when the printing plate is in the specific state, pushing an edge of the printing plate orthogonal to the sub-scanning direction to move the position of the printing plate in the sub-scanning direction by a predetermined displacement amount.

11. The image recording method according to claim 10,

the drum has:

a jig groove as the groove, and

the clamp is clamped in the clamp groove;

the image recording method further includes a step c) of, after the step b), attaching a printing plate to the outer peripheral surface of the drum, and fixing an end edge of the printing plate in a main scanning direction, which is a rotation direction of the drum, between the outer peripheral surface and the jig.

12. The image recording method according to claim 11,

further comprising a step d) of irradiating the recording light from the recording head after the step c),

in the step d), the irradiation position of the recording light is moved according to the displacement amount.

13. The image recording method according to claim 10,

the method further comprises the following steps before the step b):

a process of positioning the printing plate in a standard position, and

and a step of forming a punched hole on the printing plate positioned at the standard position.

14. The image recording method according to claim 10,

the specific positions are plural and arranged symmetrically with respect to the center of the sub-scanning direction of the drum;

the step b) includes:

b-1) moving one of the two printing plates in one direction in the sub-scanning direction;

b-2) moving the other of the two printing plates in the other direction in the sub-scanning direction.