JP2003091075A - Image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record an image without lowering image quality by the movement of a recording head in a forward direction and a reverse direction in the case of recording the image by moving the recording head in the axial direction of a rotary drum while rotating a printing plate wound around the rotary drum. SOLUTION: Since the image recording is performed by moving the recording head 37 in a going-path (forward direction) and a returning-path (reverse direction), working efficiency is improved more than in the conventional recorder in which the recording head 37 merely returns in the returning-path in the image recording which is performed only in the going-path. Main scanning lines are aligned by inclining the winding of the printing plate 12 round the rotary drum 16 in an opposite direction between in a forward-direction image recording mode and in a reverse-direction image recording mode, whereby color slurring is not caused and the deterioration of the image quality is restrained.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sheet-shaped recording material wound around a peripheral surface of a rotary drum, rotated at a predetermined rotational speed (main scanning), and arranged to face the peripheral surface of the rotary drum. The present invention relates to an image recording apparatus for recording an image by moving the recording head in the axial direction of the rotary drum (sub scanning).

[0002]

2. Description of the Related Art A sheet-shaped recording material, particularly a printing plate having a photosensitive layer provided on a support is used, and the printing plate is wound around the peripheral surface of a rotary drum. A technique for recording an image directly on the photosensitive layer (emulsion surface) of the printing plate with a laser beam by moving the recording head in the axial direction of the rotating drum (sub-scanning) while rotating at high speed (main scanning). Has been developed (printing plate exposure device). With such a technique, it is possible to quickly record an image on a printing plate.

Generally, the recording head has a home position on one end face side of the rotary drum, records an image when moving from the home position side to the other end face side, and after the image recording is completed. It returns to the home position again and stands by for the next image recording.

In this case, the recording head moves at the speed VH restricted by the image recording speed at the time of recording an image, but when returning to the home position, the above speed VH is provided for improving work efficiency.
It is desirable to move at a higher speed than. Therefore, a drive system such as a servo motor for moving the recording head is designed to be able to drive in a relatively wide speed range.

Here, in the conventional configuration, it takes a little time to return the recording head to the home position, and even if the printing plate is quickly wound around or unwound on the rotary drum, the return of the recording head is awaited. Time leads to low productivity.

Further, when the moving speed range of the recording head is wide as described above, the specifications of the drive system are limited, which may lead to cost increase and enlargement of the apparatus.

In order to solve this, as is well known in so-called ink jet printers, an image is recorded in both the forward direction (movement from the home position) and the reverse direction (movement to the home position) of the recording head. It is possible to continue.

However, in the printing plate exposing device,
Since the rotary drum is rotated and the recording head is moved at the same time, the main scanning line is inclined with respect to the printing plate. Since this is an inclination in a direction in which the forward pass and the backward pass are opposite to each other, for example, color misregistration occurs between the printing plates that form one set of four color images, and the image quality is deteriorated. There is a problem peculiar to the winding type exposure apparatus.

In consideration of the above facts, the present invention makes it possible to rotate a sheet-shaped recording material wound on a rotary drum,
Image recording apparatus capable of realizing image recording by moving the recording head in the forward direction and in the reverse direction without degrading the image quality when the recording head is moved in the axial direction of the rotating drum to record an image The purpose is to obtain.

[0010]

According to a first aspect of the present invention, a sheet-shaped recording material is wound around a peripheral surface of a rotating drum, and is rotated at a predetermined rotation speed (main scanning). Is an image recording apparatus for recording an image by moving a recording head, which is arranged to face the peripheral surface of the rotary drum, in the axial direction of the rotating drum (sub-scanning), and rotating the rotating drum at a predetermined speed at a constant speed. Recording for moving the control means and the recording head at a predetermined speed in each of the forward direction from one end to the other end of the rotary drum and the reverse direction from the other end to the one end. An image for reading the image data in the forward direction when the head movement control means and the recording head move in the forward direction, and an image for reading the image data in the reverse direction when moving the recording head in the reverse direction. Data reading direction setting hand And the inclination angle θ of the main scanning line at the time of image recording, which is determined by the rotation speed of the rotating drum and the moving speed of the recording head, with respect to the terminal side of the sheet-shaped recording material, when the image is recorded in either the forward direction or the reverse direction And the winding angle of the sheet-shaped recording material with respect to the rotating drum so that the image recording result of the other of the forward direction and the reverse direction becomes the inclination angle θ recognized by the inclination angle recognizing means. Wrapping angle setting means to be set,
have.

According to the first aspect of the invention, the inclination angle θ of the main scanning line can be known from the rotational speed of the rotary drum and the moving speed of the recording head.

When the image is recorded in either one of the forward direction and the reverse direction, the tilt angle is recognized so that it matches the recognized tilt angle θ when the other image is recorded in the forward direction and the reverse direction which is subsequently executed. By setting the winding angle of the sheet-shaped recording material around the rotary drum, it is possible to match the main scanning lines between the time of image recording in the forward direction and the time of image recording in the reverse direction.

According to a second aspect of the present invention, the sheet-shaped recording material is wound around the peripheral surface of the rotary drum and is rotated at a predetermined rotational speed (main scanning), and is arranged to face the peripheral surface of the rotary drum. An image recording apparatus for recording an image by moving the recording head in the axial direction of the rotary drum (sub-scanning), comprising drum rotation control means for rotating the rotary drum at a predetermined speed at a constant speed, and the recording apparatus. Recording head movement control means for moving the head at a predetermined speed in each of the forward direction from one end of the rotary drum to the other end, and the reverse direction from the other end to the one end, Image data read direction setting means for reading the image data in the forward direction when the recording head moves in the forward direction, and reading the image data in the reverse direction when moving the recording head in the reverse direction. , The forward direction And the reverse direction, the rotary drum of the sheet-shaped recording material of the main scanning line at the time of image recording in which the forward direction and the reverse direction, which are determined by the rotation speed of the rotating drum and the moving speed of the recording head, conflict with each other. Inclination angle recognizing means for recognizing the inclination angles θF, θR with respect to the terminal side in the winding direction, and the inclination angles θF, θR recognized by the inclination angle recognizing means are respectively parallel to the terminal side.
And a wrapping angle setting means for setting a wrapping angle of the sheet-shaped recording material with respect to the rotating drum during image recording in the forward direction and image recording in the reverse direction.

According to the second aspect of the invention, by recognizing the tilt angles θF and θR with respect to the terminal side of the sheet-like recording material of the sheet-shaped recording material in the main scanning line at the time of image recording, the respective main scanning is performed. The respective winding angles are set so that the line is parallel to the terminal side. As a result, it is possible to eliminate the deviation of the main scanning lines (angle difference in the scanning direction) during image recording in the forward direction and the backward direction.

According to a third aspect of the invention, in the invention of the second aspect, the inclination angle θF and the inclination angle θR.
Are inclined at the same inclination angle θ in opposite directions with respect to the terminal side.

According to the third aspect of the present invention, when the rotational speed of the rotary drum and the moving speed (absolute value) of the recording head are the same during image recording in the forward direction and the reverse direction, respectively,
Since the sheet-shaped recording material is normally wound (the leading edge in the winding direction is parallel to the axis of the rotating drum), the sheets are inclined at the same angle in opposite directions.
It suffices to incline at the same angle θ in which the inclination directions are different and to wind the rotary drum.

According to a fourth aspect of the invention, in the invention according to any one of the first to third aspects, a data buffer for accumulating image data input from the outside is further provided, and the image data reading is performed. It is characterized in that the direction setting means is executed at the time of reading from the data buffer.

According to a fifth aspect of the present invention, in the invention according to any one of the first to third aspects, a data buffer for accumulating image data input from the outside is further provided, and the image data reading is performed. The direction setting means is executed before being accumulated in the data buffer.

According to the invention described in claims 4 and 5, the image data is generally input from the outside. For example, when the image recording apparatus of the present invention is connected to a host computer via a network, image data is input from the host computer and is temporarily stored in a data buffer. At this time, the image data reading direction setting means may be executed when reading the data from the data buffer (claim 4) or externally (that is,
Here, it may be executed when the data is accumulated in the data buffer from the host computer).

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a printing plate automatic exposure apparatus 10 according to this embodiment.

The printing plate automatic exposure device 10 is provided with a printing plate 1.
It is divided into two blocks: an exposure unit 14 that exposes an image by irradiating the two image forming layers with a light beam, and a transport guide unit 18 that transports the printing plate 12 to the exposure unit 14. The printing plate 12 exposed by the printing plate automatic exposure device 10 is sent to a developing device (not shown) installed adjacent to the printing plate automatic exposure device 10.

The exposure unit 14 is mainly composed of a rotary drum 16 for winding and holding the printing plate 12 on its peripheral surface. The printing plate 12 is guided by a conveyance guide unit 18 and is rotated by the rotary drum 16. It is designed to be fed in from the tangential direction. The transport guide unit 18 includes a plate supply guide 20 and a plate discharge guide 22.

A plate feed guide 20 of the transport guide unit 18
The relative positional relationship between the plate discharge guide 22 and the plate discharge guide 22 is a horizontal V-shape, and is configured to rotate a predetermined angle around the center of FIG. By this rotation, the plate feeding guide 2
0 or the plate discharge guide 22 is selectively associated with the rotary drum 16 (arranged in the tangential direction of the rotary drum 16).
be able to.

In addition, a punching machine 24 for punching a through hole serving as a reference for winding the printing plate 12 around a plate cylinder of a rotary press (not shown) is provided near the transport guide unit 18, By allowing the plate guide 20 to face the punching machine 24, the leading edge of the printing plate 12 can be fed to the punching machine 24. That is, the printing plate 12
First, the sheet is guided by the plate feed guide 20 and fed into the punching machine 24. After punching, for example, a circular hole and a long hole at the tip of the printing plate 12, the sheet is once returned to the plate feed guide 20. After that, by rotating the transport guide unit 18, the printing plate 12 is moved to a position corresponding to the rotary drum 16.

FIG. 2 shows the transport guide unit 18 in a state where the plate discharge guide 22 is removed (that is, only the plate feed guide 20 is attached).

A pair of pusher units is provided at the end of the plate feed guide 20 opposite to the rotary drum 16 (the end on the front side in FIG. 2).

This pusher unit includes a pressing portion 68 provided on the surface (upper surface) of the plate feed guide and the pressing portion 6.
And a supporting shaft (not shown) that rotatably supports the plate 8, the supporting shaft penetrating a pair of slit holes 20A provided in the plate feeding guide 20 and the back surface (lower surface) of the plate feeding guide 20. Penetrates to the side.

Next, corresponding to the pusher unit, a pair of positioning pins 74 capable of projecting and retracting from the surface of the plate feeding guide 20 are provided at the end of the plate feeding guide 20 on the rotary drum 16 side. . Also, a pair of positioning pins 7
As shown in FIG. 5, 4 can be moved point-symmetrically in the direction toward and away from the rotary drum 16.

The positioning pin 74 can be set at two positions, that is, a projecting position that projects above the surface of the plate feeding guide 20 and a retracted position that retracts below the surface of the plate feeding guide 20.

A widthwise pusher unit 84 movable along the axial direction of the rotary drum 16 is provided at one widthwise end of the plate feed guide 20 (left end in FIG. 2).

The widthwise pusher unit 84 has a pressing portion 86 provided on the surface (upper surface) of the plate feed guide and a support shaft (not shown) for rotatably supporting the pressing portion 86.
The support shaft penetrates the slit hole 20B provided in the plate feeding guide 20 and penetrates to the back surface (lower surface) side of the plate feeding guide 20.

As shown in FIG. 2, the slit hole 20B.
Are extended in the axial direction of the rotary drum 16. As a result, the width direction pusher unit 84 can move along the slit hole 20B of the plate feed guide 20 in parallel to the axial direction of the rotary drum 16.

On the other hand, as shown in FIG. 2, the plate feeding guide 2
A pair of positioning pin units 92 movable along the axial direction of the rotary drum 16 are provided at the other widthwise end portion of 0 (the right end portion in FIG. 2).

The positioning pin unit 92 is a positioning pin 94 provided on the surface (upper surface) of the plate feed guide 20.
And a support shaft that rotatably supports the positioning pin 94.
(Not shown), the support shaft passes through a pair of slit holes 20C provided in the plate feed guide 20 and penetrates to the back surface (lower surface) side of the plate feed guide 20.

As shown in FIG. 2, the slit hole 20C
Are parallel to each other and extend in the axial direction of the rotary drum 16. As a result, the positioning pin unit 94
Can be moved in parallel with the axial direction of the rotary drum 16 along the slit holes 20C of the plate feed guide 20, and are arranged at the positioning position in advance depending on the size of the printing plate 12.

The rotating drum 16 is driven by a driving means (not shown) so that the mounting exposure direction of the printing plate 12 (direction of arrow A in FIG. 1) and the direction of removal of the printing plate 12 opposite to the mounting exposure direction (arrow B of FIG. 1). Direction).

As shown in FIG. 1, a tip chuck 26 is attached to the rotary drum 16 provided in the exposure section 14 at a predetermined position on the outer peripheral surface. Exposure unit 14
Then, when the printing plate 12 is mounted on the rotary drum 16, first, the tip chuck 26 is moved by the transport guide unit 1
Rotating drum 1 at a position (printing plate mounting position) facing the front end of printing plate 12 fed by plate feeding guide 20
Stop 6

The exposure unit 22 is provided with a mounting cam 28 facing the tip chuck 26 at the printing plate mounting position.
The tip chuck 26 can insert the printing plate 12 between itself and the peripheral surface of the rotating drum 16 by rotating the mounting cam 28 and pressing one end side thereof.

In the exposure section 14, with the front end of the printing plate 12 inserted between the front end chuck 26 and the rotary drum 16, the mounting cam 28 is returned to release the pressure on the front end chuck 26 to release the printing plate. The tip of 12 is clamped and held between the tip chuck 26 and the peripheral surface of the rotary drum 16.

At this time, the printing plate 12 is in contact with a pair of positioning pins 100 and 102, the tip surfaces of which project at predetermined positions on the peripheral surface of the rotary drum 16, and the width direction of the printing plate 12 is abutted. One end of the rotary drum 16 comes into contact with a positioning pin 104 projecting from one end of the rotary drum 16 in the axial direction, and the rotary drum 16 is finally positioned. Note that the positioning pins 100 and 102 are movable point-symmetrically with respect to each other in the circumferential direction of the rotary drum 16, as shown in FIG.

In the exposure section 14, when the front end of the printing plate 12 is fixed to the rotary drum 16, the rotary drum 16 is rotated in the mounting exposure direction. As a result, the transport guide unit 18
The printing plate 12 fed from the plate feeding guide 20 is wound around the peripheral surface of the rotating drum 16.

In the vicinity of the peripheral surface of the rotary drum 16, the squeeze roller 3 is located downstream of the printing plate mounting position in the mounting exposure direction.
0 is placed. The squeeze roller 30 moves toward the rotary drum 16 to move the rotary drum 16.
The printing plate 12 wound on the rotary drum 16 is pressed against the rotating drum 16 to bring the printing plate 12 into close contact with the peripheral surface of the rotating drum 16.

The exposure unit 14 includes a squeeze roller 3
A trailing edge chuck attachment / detachment unit 32 is arranged near the downstream side of the rotation exposure direction of the rotary drum 16 with respect to zero. A rear end chuck 36 is attached to the rear end chuck attachment / detachment unit 32 at the tip of a shaft 34 protruding toward the rotary drum 16.

In the exposure section 14, the trailing edge of the printing plate 12 wound around the rotating drum 16 is the trailing edge chuck attaching / detaching unit 3
When facing 2, the shaft 34 is projected and the rear end chuck 36 is mounted at a predetermined position on the rotary drum 16. As a result, the trailing edge chuck 36 holds and holds the trailing edge of the printing plate 12 with the rotating drum 16.

In the exposure section 14, when the front end and the rear end of the printing plate 12 are held by the rotating drum 16, the squeeze roller 30
Separate. After that, in the exposure unit 14, the rotary drum 1
While rotating 6 at a predetermined rotation speed at high speed, the recording head 37 irradiates a light beam modulated based on image data in synchronization with the rotation of the rotating drum 16. As a result, the printing plate 12 is scanned and exposed based on the image data.

In the exposure section 14, when the scanning exposure of the printing plate 12 is completed, the rotary drum 16 is moved to the position where the rear end chuck 36 holding the rear end of the printing plate 12 faces the rear end chuck attaching / detaching unit 32. Pause the rotating drum 16
Then, the rear end chuck 36 is removed. As a result, the trailing edge of the printing plate 12 is opened.

After that, by rotating the rotary drum 16 in the take-out direction of the printing plate 12, the printing plate 12 is discharged from the rear end side to the plate discharge guide 22 of the transport guide unit 18 along the tangential direction of the rotary drum 16. After that, it is conveyed to the developing device in the next step.

Here, in the present embodiment, the rotary drum 1
When moving the recording head 37 while rotating 6 to record an image, the order of recording the image while moving the recording head 37 from one end (home position side) of the rotary drum 16 to the other end The direction image recording mode and the reverse direction image recording mode in which an image is recorded while moving the recording head 37 from the other end of the rotary drum to the one end (home position side) are alternately executed. ing.

At this time, since the rotating drum 16 is rotated and the recording head 37 is moved at the same time, the main scanning line is inclined with respect to the rotating direction of the rotating drum 16. This tilt direction is the opposite direction in the forward image recording mode and the reverse image recording mode. With this, between the printing plates that will be a set for forming a color image,
This will cause color misregistration.

Therefore, in the present embodiment, when the printing plate 12 is wound around the rotary drum 16, the front end side of the printing plate 12 in the winding direction is parallel to the axis of the rotary drum 16 as a reference (0
°) as the forward image recording mode (see FIG. 5 (A))
Then, it is wound with a predetermined angle (angle + θ) tilted counterclockwise. In this case, the positioning pin 74 (or 10
(0, 102) is rotated point-symmetrically in the counterclockwise direction, whereby abutting and positioning can be performed.

On the other hand, the reverse image recording mode (FIG. 5B)
In (1), the tape is wound with a predetermined inclination (angle −θ) in the clockwise direction. In this case, the abutting positioning can be performed by rotating the positioning pin 74 (or 100, 102) in a clockwise direction symmetrically with respect to the point.

In the forward image recording mode and the backward image recording mode, the reading order of the image data is opposite, so it is necessary to execute the reading control according to each mode.

FIG. 4 shows a control system for rotating the rotary drum 16, moving the recording head 37, and recording an image by the recording head 37 based on an image signal.

The rotary drum 16 is rotated by the driving force of the servo motor 200. The rotation speed of the servo motor 200 is controlled based on a drive signal from the rotary drum drive control unit 204 of the controller 202.

In the recording head 37, the shaft 204 on which the male screw of the ball screw mechanism is formed is attached to the motor 206.
By rotating the shaft by, the moving drum 16 moves in the axial direction. This motor 206 is a controller 202
The drive speed is controlled based on the drive signal from the print head drive control unit 208.

A rotary encoder 250 is attached to one side of the rotary shaft 16A of the rotary drum 16. The rotary encoder 250 includes the rotary drum 16
A pulse signal is output in accordance with the rotation of, and this reference position signal is input to the 1 / M frequency dividing circuit 252.

The 1 / M frequency dividing circuit 252 frequency-divides the input pulse signal by 1 / M and sends it to a PLL (Phase Locked Loop) circuit 254. In this PLL circuit 254, the 1 / M frequency-divided pulse signal is converted into the 1 / N frequency divider circuit 2
By being fed back via 56, control is performed so as to match the phase with the pulse signal divided by 1 / N.
This causes the 1 / M input from the PLL circuit 254.
A pulse signal obtained by adding (N / M) to the divided pulse signal is output as an image writing clock pulse signal.

The image writing clock pulse signal output from the PLL circuit 254 is input to the exposure control section 210 of the controller 202.

The image data generated by the exposure controller 210 is sent to the head controller 218. The head controller 218 controls the recording head 37,
The printing plate 12 is irradiated with a light beam modulated based on the input image data, and an image is recorded on the printing plate 12 by the rotation of the rotary drum 16 (main scanning) and the movement of the recording head 37 (sub scanning). To do.

The exposure control section 210 includes a data reading section 2
The image data read from the data buffer 214 by 12 is input. The reading order of the data reading unit 212 from the data buffer 214 is controlled by the image recording mode signal from the image recording direction determining unit 216. The image recording mode signal from the image recording determination unit 216 is also sent to the recording head drive control unit 208.

Since the image recording direction discriminating unit 216 alternately executes the image recording mode in the forward image recording mode and the backward image recording mode, the signal inverting unit 220 inverts the signal every time an image recording instruction is issued. The image recording mode can be determined based on the signal from the. The image recording instruction signal is also sent to the recording head drive control unit 208 and the rotary drum drive control unit 204 to drive the recording head 37 and the rotary drum 16, and the image recording control of the recording head 37 by the exposure control unit 210. And are synchronized with each other.

The operation of this embodiment will be described below.

First, the printing plate 12 is placed on the plate feed guide 20. At this time, so-called manual feeding may be used, or feeding may be performed by an automatic sheet feeding device or the like.

Printing plate 12 placed on plate supply guide 20
Are supported relatively roughly (such as the placement position and the inclination with respect to the plate feed guide 20), and by operating the pusher unit in this state, the printing plate 12 is pressed to the vicinity of a predetermined temporary positioning position. At this time, since at least two pressing portions contact the printing plate 12, the inclination is corrected during the pressing movement.

In the transportation to the rotary drum 16, the positioning pin 74 provided at the end of the plate feed guide 20 on the rotary drum 16 side is positioned at the projecting position.
2 contacts the positioning pin 74 and is provisionally positioned.

Then, by moving the pressing portion 86 of the width direction pusher unit 84, the printing plate 12 comes into contact with the positioning pin 94 which is arranged at a predetermined position based on the size of the printing plate 12 in advance, thereby printing. Temporary positioning of the plate 12 in the width direction is executed.

In this temporary positioning state, after the positioning pin 74, which is the protruding position, is moved to the retracted position, the printing plate 1 is further pressed by the pressing portion 68 of the pusher unit.
2 is moved toward the rotary drum 16 and brought into contact with the pair of reference pins 100 and 102 provided on the rotary drum 16. As a result, the position and inclination of the leading edge of the printing plate 12 are corrected.

Next, in this state, the printing plate 12 is moved in the width direction by the pressing portion 86 of the width direction pusher unit 84 and brought into contact with the reference pin 104. Since the position in the width direction is substantially determined by the positioning pin 94 (temporary positioning shown in FIG. 2), an error caused by a slight movement of the printing plate 12 from the temporary positioning position is corrected. As a result, the printing plate 12 becomes the rotary drum 1.
6 is a unique position (main positioning shown in FIG. 3).

The printing plate 12 sent to the rotary drum 16 and finally positioned is tightly wound around the peripheral surface of the rotary drum 16 by the front end chuck 26 and the rear end chuck 36, and the preparation for exposure is completed.

The image data is read, and the exposure process is started by the light beam from the recording head 37. The exposure processing is so-called scanning exposure in which the recording head 37 is moved in the axial direction of the rotating drum 16 while rotating the rotating drum 16 at high speed (main scanning). This scanning exposure control will be described later.

When the exposure process is completed, the conveyance guide unit 18 is switched (the plate discharge guide 22 is made to correspond to the rotary drum 16), and then the printing plate 12 wound around the rotary drum 16 is discharged in the tangential direction. At this time, the printing plate 12 is sent to the plate discharge guide 22.

When the printing plate 12 is sent to the plate ejection guide 22, the conveyance guide unit 18 is switched to move the plate ejection guide 2
2 is made to correspond to the discharge port, and the printing plate 12 is discharged. A developing unit is provided in the discharging direction, and the printing plate 12 is continuously developed.

Here, in the printing plate automatic exposure apparatus 10 according to the present embodiment, the order in which image recording is performed while moving the recording head 37 from one end of the rotary drum 16 having the home position to the other end thereof. The direction image recording mode and the reverse direction image recording mode in which image recording is performed while moving the rotary drum from the other end to the one end are alternately performed.

At this time, as shown in FIG. 5A, in the forward image recording mode, the positioning pin 74 (or 10) is used.
(0, 102) is rotated counterclockwise in a point-symmetrical manner, and when the printing plate 12 is wound around the rotating drum 16, the front end side in the winding direction of the printing plate 12 is set to be parallel to the axis of the rotating drum 16. As (0 °), it is wound with a predetermined angle (angle + θ) tilted counterclockwise.

Further, as shown in FIG. 5B, in the reverse image recording mode, the positioning pin 74 (or 100,
102) is rotated pointwise symmetrically in the clockwise direction, and when the printing plate 12 is wound around the rotary drum 16, the front side in the winding direction of the printing plate 12 is parallel to the axis of the rotary drum 16 as a reference (0 °). ) As a predetermined angle (angle −
θ) Incline and wind.

The rotary drum 16 of the printing plate 12 as described above
By performing the above two modes alternately after winding, the image recording states in both modes (the tilting state of the main scanning line with respect to the printing plate 12) match, and especially for color image creation. In the case where the four printing plates created for each color are set, the color misregistration can be prevented.

In the following, according to the flowchart of FIG. 6, in the forward image recording mode and the backward image recording mode,
An image recording control routine including image reading control for reversing the image data reading order will be described.

In step 300, plate supply control is executed. At this time, the plate feeding control system recognizes the next image recording mode, and the position of the positioning pin 74 (100, 102) is changed according to the recognized image recording mode, and the winding on the rotary drum 16 is performed. Is executed.

At the next step 302, it is judged whether or not there is an image recording instruction, and if an affirmative judgment is made, the routine proceeds to step 304, where the inversion signal is inverted. This inversion signal is a signal that is inverted every time the image recording instruction signal is input, and by this, the next image recording mode is recognized.

In the next step 306, it is judged based on the inversion signal whether or not the forward image recording mode is set. If it is judged that the image is in the forward image recording mode, step 308 follows and the data buffer 214 reads the normal state. Then, the data is read out and the process proceeds to step 312. Further, when a negative determination is made in step 306, that is, when the reverse image recording mode is determined, the process proceeds to step 310, the data is read from the data buffer 214 in the inverted state, and the process proceeds to step 312.

In step 312, the rotation of the rotary drum 16 is started, and then in step 314, the one-way drive of the recording head 37 is started.

At the next step 316, the image data is sequentially transferred to the recording head 37, and steps 316 and 3 are executed until the transfer of all the data is completed at step 318.
Repeat 18.

If it is determined in step 318 to end, the process proceeds to step 320 to stop the rotation of the rotary drum 16, then in step 322 the plate discharge control is executed, and this routine ends.

According to the present embodiment, since the recording head 37 performs the image recording on the forward path (forward direction) and the backward path (reverse direction), the conventional method is that the backward path is only returned by the image recording on the forward path. It is possible to improve work efficiency as compared with.

Such reciprocal image recording is well known in so-called ink jet printers and the like, but the printing plate 12 is wound around the rotary drum 16 and the recording head 37 is moved along the axis of the rotary drum 16. However, in the printing plate automatic exposure device 10 that records an image, the main scanning lines incline in opposite directions during forward image recording and during reverse image recording, so that four plates are set for color image formation. When an image is recorded for each color, color shift may occur.

However, in the present embodiment, in the forward image recording mode and the backward image recording mode, the main scanning line is set to the printing plate 12 when the printing plate 12 is wound around the rotating drum 16.
Since the leading end side of the winding direction is inclined by a predetermined angle (angle + θ, −θ) in the rotation direction opposite to the axis of the rotating drum 16, as a result, the main scanning line at the time of image recording in each mode is reduced to one. However, the color shift is not caused, and the deterioration of the image quality can be suppressed.

Further, since the reading of the image data is also reversed in the forward image recording mode and the backward image recording mode, the image data can be stored in the normal state at the stage of storing in the data buffer 214. For example, the recording head 37 is driven one way, but a quick response can be taken even if a situation such as passing image recording occurs.

In this embodiment, the printing plate 12 is tilted and wound around the rotating drum 16 in both the forward image recording mode and the backward image recording mode with the rotating drum axis as a reference. Alternatively, one side may be used as a reference (that is, the printing plate 12 may be wound in a normal state), and the other side may be tilted so as to match the reference printing plate 12.

Further, in the above embodiment, the inclination angle θF of the main scanning line in the forward image recording mode and the inclination angle θR of the main scanning line in the backward image recording mode are the same (the absolute value is However, if the moving speed of the recording head 37 or the rotating speed of the rotary drum 16 is different in each mode, the inclination angles of the both may be different (θF ≠ θR). . in this case,
The winding angle may be set for each inclination angle with reference to the winding of the printing plate 12 in the normal state.

Further, in the present embodiment, the image recording direction discriminating unit 216 after reading from the data buffer 214.
Although the image data is read by the data reading unit 212 based on the result of the determination in the above, for example, when the printing plate automatic exposure device 10 of the present embodiment is connected to a host computer via a network, Before the data is input from the computer to the data buffer 214 and stored, the data may be stored based on the result determined by the image recording direction determination unit 216.

[0091]

As described above, according to the present invention, when the printing head is moved in the axial direction of the rotary drum while the printing plate is wound around the rotary drum and the image is printed, the order of the print heads is changed. It has an excellent effect that image recording can be realized by moving in the direction opposite to the direction without deteriorating the image quality.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a printing plate automatic exposure apparatus according to the present embodiment.

FIG. 2 is a perspective view of the transport guide unit with the plate discharge guide removed (temporary positioning of the printing plate).

FIG. 3 is a perspective view of the transport guide unit with the plate discharge guide removed (printing plate book positioning state).

FIG. 4 is a block diagram showing a control system for image recording control.

FIG. 5 is a plan view showing an inclined state of the printing plate.

FIG. 6 is a flowchart showing an image recording control routine.

[Explanation of symbols]

10 Automatic printing plate exposure device 12 printing plates 14 Exposure unit 20 Plate Supply Guide 37 recording head 200 servo motor 202 controller 204 shaft 206 motor 208 recording head drive controller 210 exposure control unit 212 Data reading unit 214 data buffer 216 Image record determination unit 218 Head Controller 220 signal inversion unit 250 rotary encoder

Claims (5)

[Claims] 1. A sheet-shaped recording material wound around a peripheral surface of a rotary drum is rotated at a predetermined rotation speed (main scanning), and a recording head disposed opposite to the peripheral surface of the rotary drum is rotated. Is an image recording apparatus for recording an image by moving in the axial direction of the (sub scanning), a drum rotation control means for rotating the rotary drum at a constant speed at a predetermined speed, and the recording head for one of the rotary drums. Recording head movement control means for moving at a predetermined speed in each of the forward direction from the end portion to the other end portion and in the reverse direction from the other end portion to the one end portion, and in the forward direction of the recording head. Image data reading direction setting means for reading the image data in the forward direction when moving the recording head, and image data reading direction setting means for reading the image data in the reverse direction when moving the recording head in the reverse direction, and the forward direction or the backward direction. One picture An inclination angle recognizing means for recognizing an inclination angle θ of the main scanning line with respect to the terminal side of the sheet-shaped recording material at the time of image recording, which is determined by the rotation speed of the rotary drum and the moving speed of the recording head during recording; Or, an image having a winding angle setting means for setting the winding angle of the sheet-shaped recording material with respect to the rotating drum so that the other image recording result in the opposite direction becomes the inclination angle θ recognized by the inclination angle recognizing means. Recording device. 2. A sheet-shaped recording material wound around a peripheral surface of a rotary drum is rotated at a predetermined rotation speed (main scanning), and a recording head disposed opposite to the peripheral surface of the rotary drum is rotated. Is an image recording apparatus for recording an image by moving in the axial direction of the (sub scanning), a drum rotation control means for rotating the rotary drum at a constant speed at a predetermined speed, and the recording head for one of the rotary drums. Recording head movement control means for moving at a predetermined speed in each of the forward direction from the end portion to the other end portion and in the reverse direction from the other end portion to the one end portion, and in the forward direction of the recording head. Image data reading direction setting means for reading the image data in the forward direction when the recording head moves, and image data reading direction setting means for reading the image data in the backward direction when the recording head moves in the reverse direction, and the forward direction and the backward direction. Both sides of During recording, the main scanning line at the time of image recording, which is opposite to the forward direction and the reverse direction determined by the rotating speed of the rotating drum and the moving speed of the recording head, is inclined with respect to the terminal side of the rotating drum winding direction of the sheet-like recording material. Inclination angle recognizing means for recognizing the angles θF and θR, and an image in a direction opposite to that in the image recording in the forward direction so that the inclination angles θF and θR recognized by the inclination angle recognizing means are parallel to the terminal side, respectively. An image recording apparatus having a winding angle setting means for setting a winding angle of a sheet-shaped recording material with respect to a rotating drum at the time of recording. 3. The image recording apparatus according to claim 2, wherein the tilt angle θF and the tilt angle θR are tilted at the same tilt angle θ in opposite directions with respect to the terminal side. 4. A data buffer for accumulating image data input from the outside is further provided, and the image data read direction setting means is executed at the time of reading from the data buffer. To claim 3
The image recording apparatus according to any one of 1. 5. A data buffer for accumulating image data input from the outside, further comprising: said image data read direction setting means being executed before accumulating in said data buffer. The image recording apparatus according to claim 3.