JP4505047B2 - Exposure equipment - Google Patents

Description

  The present invention relates to an exposure process in an exposure apparatus in which a plurality of laser light sources are discretely arranged.

  As a CTP (Computer To Plate) apparatus that directly forms an image on a printing plate, a CTP apparatus using a laser diode (LD) as an exposure head (light source) has been widely known. As an exposure method of the CTP apparatus, a multi-beam method in which exposure is performed by simultaneously irradiating light from a plurality of laser diodes is widely adopted.

  For example, an exposure head (multi-channel optical head) having a plurality of laser diodes arranged in one direction and a lens that forms an image of the laser light emitted from the plurality of laser diodes at an exposure position. A spiral exposure system that exposes almost the entire surface of a printing plate by irradiating laser light from a laser diode while moving the exposure head in the axial direction of the drum while the drum (plate cylinder) provided with the plate is rotated. A CTP device is known (see, for example, Patent Document 1).

  Further, the exposure head has an exposure head in which a plurality of laser diodes are discretely arranged at equal intervals, and the drum (plate cylinder) provided with a printing plate is rotated, and the exposure head is moved in the axial direction of the drum. By irradiating the plate directly with laser light from each laser diode while moving the distance corresponding to the interval, multiple partial areas are exposed simultaneously in parallel, and finally the plate A CTP apparatus that exposes the entire surface is also known (see, for example, Patent Document 2).

JP 2000-43317 A JP 2003-89180 A

  In Patent Document 1, when laser diodes are grouped into two parts, the first half and the second half, and the laser diode belonging to either the first half or the second half does not emit light (lights) due to damage, A technique is disclosed in which exposure is performed using only the laser diode belonging to the first half so that exposure can be continued without stopping the apparatus until the laser diode is replaced even if damage occurs. .

  However, this method has a problem that exposure cannot be performed when the laser diodes belonging to the first half and the second half are not lit.

  In the first place, such a method is intended for a spiral exposure CTP apparatus as disclosed in Patent Document 1. In the CTP apparatus in which a plurality of laser diodes are discretely arranged as disclosed in Patent Document 2, the movement range of individual laser diodes during exposure is limited. It is not possible to apply a technique as disclosed in Patent Document 1 in which the latter half of the laser diode is exposed to the area that should be originally exposed.

  The present invention has been made in view of the above problems, and is a CTP device in which a plurality of laser diodes are discretely arranged, and continues even if a state in which some of the laser diodes do not emit light due to damage or the like occurs. It is an object of the present invention to provide a CTP device that can be used in a practical manner.

In order to solve the above problems, an invention of claim 1 is an exposure apparatus that exposes an object to be exposed, a holding body that holds the object to be exposed, a plurality of light sources that can emit exposure light simultaneously, and An exposure head in which a plurality of light sources are discretely arranged at equal intervals in the arrangement direction along the object to be exposed, a moving means for moving the exposure head along the object to be exposed, and the content of exposure to the object to be exposed Exposure data input means for acquiring the described overall exposure data, exposure data generation means for each channel for generating exposure data for each channel describing the exposure contents in each of the plurality of light sources based on the overall exposure data, and the channel Exposure control means for controlling the plurality of light sources so as to emit exposure light according to the description content of the separate exposure data, and the plurality of light sources are all in a light emitting state. , The said channel-by-channel exposure data such that all of the plurality of light sources by using the exposure light emitted from the formation of the area to be exposed is generated, the plurality of light sources in the arrangement direction by said moving means The exposure control means emits exposure light from the plurality of light sources in accordance with the channel-specific exposure data while moving the exposure head only between reference intervals having distances that substantially coincide with the interval. formed, among the plurality of light sources, if the arrangement order is odd source only or the arrangement order in the arrangement direction is only the even-numbered light source is a non-emission state, in addition to the reference period, the in at least one of the front and rear of the reference interval in the arrangement direction is provided continuously to the reference section, it has a natural multiple distance of the reference interval While so moving said exposure head even complete section, said channel as odd in the arrangement order and the a non-emission state light source to form the area to be exposed by using the exposure light from the opposite light source Separate exposure data is generated, and the exposure controller moves the exposure head in the reference interval and the complementary interval by the moving means, and the exposure control means is opposite to the light source in the non-light emitting state according to the exposure data for each channel. The exposure area is formed by emitting exposure light from the light source.

According to a second aspect of the present invention, in the exposure apparatus according to the first aspect of the present invention, the exposure apparatus further includes a non-emission detection unit that detects that the plurality of light sources are in a non-emission state, and is based on detection contents of the non-emission detection unit. Te, a light source that is used for exposure with the movement range of the exposure head is determined, characterized in that.

The invention according to claim 3, in exposure apparatus according to claim 1 or claim 2, the light source in the non-emission state of the plurality of light sources, even-numbered source and the odd-numbered the arrangement order in the arrangement direction and a light source, and, if none of the light source in the the non-emission state is not adjacent in the arrangement direction, the original light source in a non-emission state, the region to be subjected to exposure, the The channel-specific exposure data is generated so that exposure is performed by one of the light sources adjacent to the light source in the non-light-emitting state while the exposure head moves in the complementary section.

A fourth aspect of the present invention, the exposure apparatus according to any of claims 1 to 3, a light source in the non-emission state, the arrangement order in the arrangement direction and the even-numbered source and the odd-numbered source And any two of the light sources in the non-light emitting state are adjacent to each other in the arrangement direction, the area where the adjacent light sources in the non-light emitting state should be originally exposed is: The channel-specific exposure data is generated so that a light source in a light emitting state adjacent to each light source in a non-light emitting state performs exposure while the exposure head moves in the complementary section. And

According to a fifth aspect of the present invention, in the exposure apparatus according to any one of the first to fourth aspects, the complementary section having a distance more than twice the reference section is provided after the reference section. And

According to the first to fifth aspects of the present invention, even if some of the plurality of light sources are in a non-light emitting state due to damage or the like, the image recording process is performed without stopping the apparatus until replacement. Can be performed continuously.

It is a perspective view which shows the main operation | movement parts of the CTP apparatus 100 which concerns on 1st Embodiment. 2 is a block diagram schematically showing elements related to operation control of the CTP device 100. FIG. FIG. 4 is a diagram for explaining a basic operation in image recording in the CTP device 100. FIG. 4 is a diagram for explaining a basic operation in image recording in the CTP device 100. It is a figure which shows the relationship between the position of the exposure head 5, and the small image recorded by exposure. It is a figure showing the relationship between the head movement area in the normal mode, the light emission / non-light emission state of the laser diode 31 of each channel, and the image recording contents in each channel. It is a figure which illustrates the relationship between the light emission state of each ch and the image recording content in each ch in the first case where there is a non-light emitting channel. It is a figure which illustrates the relationship between the light emission state of each channel, and the image recording content in each channel in the 2nd case with the channel of a non-light-emission state. It is a figure which illustrates the relationship between the light emission state of each channel, and the image recording content in each channel in the 2nd case with the channel of a non-light-emission state. It is a figure which illustrates the relationship between the light emission state of each channel, and the image recording content in each channel in the 3rd case with the channel of a non-light-emission state. It is a figure which illustrates the relationship between the light emission state of each channel, and the image recording content in each channel in the 3rd case with the channel of a non-light-emission state. It is a figure which shows a modification. It is a figure showing the relationship between the head movement area in the normal mode of 2nd Embodiment, the light emission / non-light emission state of the laser diode 31 of each channel, and the image recording content in each channel. It is a figure which illustrates the relationship between the light emission state of each channel, and the image recording content in each channel when there is a non-light emitting channel. It is a figure showing the relationship between the head movement area in the normal mode of 3rd Embodiment, the light emission / non-light emission state of the laser diode 31 of each ch, and the image recording content in each ch. It is a figure which illustrates the relationship between the light emission state of each ch, and the image recording content in each ch when there is a non-light-emission state channel in a pattern characteristic to the third embodiment.

<First Embodiment>
<Device overview>
FIG. 1 is a perspective view showing a main operation part of the CTP device 100 according to the first embodiment of the present invention. The CTP device 100 performs on / off in units of pixels based on predetermined exposure data from the laser light source provided in the exposure head 5 on the surface of the printing plate P as an exposure target disposed on the side surface of the drum 1. This is an apparatus for forming an exposure image by exposing a photosensitive material on the surface of the printing plate P as an exposed object by irradiating laser light. That is, the CTP apparatus 100 is an apparatus having a function as an exposure apparatus. In particular, as will be described later, the CTP device 100 according to the present embodiment irradiates laser beams simultaneously from N (N is a natural number) laser diodes 31 that are discretely arranged at equal intervals. A plurality of partial areas (small images) are exposed to each other, and finally one exposure image (large image) is exposed on substantially the entire surface of the printing plate.

  The drum 1 is a cylindrical member that rotates about a rotation axis AX by being driven by a drum driving unit 6 (for example, a drive motor).

  The exposure head 5 has a structure in which N LD units 30 are discretely arranged at a constant interval w along a direction parallel to the rotation axis AX. Each LD unit 30 includes a laser diode (LD) 31 as a laser light source. That is, the exposure head 5 is provided with N laser diodes 31. In the CTP apparatus 100 according to the present embodiment, no lens or calibration sensor is provided between the laser diode 31 and the drum 1 (or the printing plate P disposed on the side surface). That is, the light emitted from the laser diode 31 is directly applied to the printing plate P.

  The exposure head 5 is guided in a direction (sub-scanning direction) parallel to the rotation axis AX along an exposure head guide (not shown) by the operations of the head moving ball screw 3 and the head moving motor 4. Yes.

  In the CTP apparatus 100 according to the present embodiment, a distance ky that is k times the distance w between the laser diodes 31 (k is a natural number of 2 or more) is secured as the movement range of the exposure head 5. Here, the value of k may be appropriately determined according to the processing mode when the laser diode 31 is in a non-light emitting state, which will be described later. However, as a practical value, k = 3 or k = 4. It is.

  In the present embodiment, the N laser diodes 31 provided in the exposure head 5 are arranged in order from the laser diode 31 provided on one end side of the exposure head 5, and the laser diodes 31, 2 of one channel (1 ch). The channel (2ch) laser diode 31,... N channel (Nch) laser diode 31 or the like, or simply referred to as 1ch, 2ch,. In addition, the fact that the laser diode of each channel (each channel) is in the light emission / non-light emission state may simply be referred to as each channel being in the light emission / non-light emission state.

  FIG. 2 is a block diagram schematically showing elements related to operation control of the CTP device 100. Main control means 11, exposure data input means 12, drum drive control means 13, head drive control means 14, channel-specific exposure data generation means 15, LD control means 16, LD drive means 17, non-light emitting Detection means 18 is further provided.

  The main control unit 11 includes, for example, a CPU, a ROM, a RAM, and the like (not shown), and comprehensively controls the overall operation of the CTP device 100. The exposure data input unit 12 acquires exposure data describing on / off information of laser light (that is, equivalent to binarization information of an exposure image) in pixel units during exposure. Normally, one exposure data is given for each exposure image (large image) to be formed on one printing plate P. The drum drive control unit 13 controls the rotation operation of the drum by the drum drive unit 6. The head drive control means 14 controls the operations of the head moving ball screw 3 and the head moving motor 4. The channel-specific exposure data generating unit 15 generates channel-specific exposure data describing the on / off operation content of the laser beam by the laser diode 31 of each channel based on the description content of the exposure data acquired by the exposure data input unit 12. Generate. That is, the contents of exposure data are distributed to N channels. The LD control unit 16 controls the light emission of the laser diode 31 by the LD driving unit 17 by applying a power voltage having a predetermined voltage value to the LD driving unit 17 based on the exposure data for each channel. The LD drive unit 17 causes the laser diode 31 to emit light by giving the laser diode 31 an operation current having a predetermined current value corresponding to the power voltage applied by the LD control unit 16.

  In the CTP apparatus 100, the main control unit 11 that holds the exposure data for each channel in advance gives predetermined control instructions to the drum drive control unit 13, the head drive control unit 14, and the LD control unit 16. The drum 1 is caused to emit laser light in each laser diode 31 at the on / off timing according to the description content of the exposure data for each channel while moving the exposure head 5 in the sub-scanning direction in synchronization with the rotation. Formation of an exposure image on the held printing plate P is realized.

  Further, in the CTP device 100, the non-emission detection means 18 monitors the light emission state of each laser diode 31, and when it is determined that a certain laser diode 31 is not emitting light, a signal for specifying this is main-controlled. Communicate to means 11. The CTP device 100 determines that the laser diode 31 is in a non-light emitting state when the light emission of the laser diode 31 does not reach a predetermined light amount when the operation current is supplied to the laser diode 31 at a predetermined value or more. To do. Specifically, the non-emission detection means 18 monitors the current value of the operation current output from the LD driving means 17 to the laser diode 31, and when the current value reaches or exceeds a predetermined value, the predetermined detection signal Is given to the main control means 11.

<Basic operation of image recording>
FIG. 3 and FIG. 4 are diagrams for explaining basic operations at the time of image recording in the CTP device 100. 3 and 4, for the sake of simplicity of explanation, it is assumed that four laser diodes 31 of the a1 channel to a4 channel are provided in the exposure head 5 at an equal interval w parallel to the rotation axis AX (N = 4) will be described as an example. Further, it is assumed that the main control unit 11 causes the channel-specific exposure data generation unit 15 to generate and hold the channel-specific exposure data based on the exposure data acquired by the exposure data input unit 12 in advance. The contents described here correspond to reference image recording described later.

  First, the drum drive control means 13 drives the drum drive means 6 to rotate the drum 1 at a predetermined speed in the X1 direction (main scanning direction) around the rotation axis AX, while driving in synchronism with the rotation. The control means 14 moves the exposure head 5 in the sub-scanning direction (Y direction) parallel to the rotation axis AX at such a speed that the drum 1 moves by a distance y while making one rotation. However, it is assumed that the relationship w = my is satisfied (m is a natural number of 2 or more).

  The LD control unit 16 applies a power voltage having a predetermined voltage value to the LD driving unit 17 at an on / off timing based on the description contents of the exposure data for each channel, so that only laser light emission with a light amount necessary for exposure occurs. Is supplied to the laser diodes 31 of the a1 channel to a4 channel, and light beams (exposure light) b1 to b4 are emitted from the respective laser diodes 31.

  As a result, each time the drum 1 makes one revolution, the exposure data for each channel whose pitch (corresponding to the reciprocal of the resolution in the sub-scanning direction) is y by the laser light emitted from the laser diodes 31 of the a1 channel to the a4 channel. An exposure image according to the above is formed. By continuing the rotation of the drum 1, the movement of the exposure head 5, and the irradiation of the laser light, exposure images (small images) are formed in the small image regions im1 to im4 as shown in FIG. When the exposure head 5 moves in the sub-scanning direction from the origin position Y0 by a distance (m−1) y = w−y, the image recording is finished. At this time, a state in which small images formed in the small image regions im1 to im4 arranged in the Y direction, which is the sub-scanning direction, are sequentially adjacent to each other is realized. That is, as a whole, the image recording of one exposure image IM is completed.

  Since the relationship w = my is satisfied, the pitch of all scanning lines is constant at y, including those formed by laser beams from different laser diodes 31. Accordingly, the gap between the small images formed in the small image areas im1 to im4 is not recognized, and it is determined that one exposure image (large image) IM is composed of a plurality of small images. Absent.

<Image recording process>
Next, a specific mode of image recording processing executed in the CTP device 100 will be described. The present embodiment is characteristic in that even if some of the laser diodes 31 provided in the exposure head 5 are in a non-light emitting state, the image recording process can be continuously executed within a predetermined range. It is.

  FIG. 5 is a diagram showing the relationship between the position of the exposure head 5 and a small image recorded by exposure. In the following, the case where k = 3, that is, the case where the exposure head 5 is configured to be movable by a distance three times the distance w between the laser diodes 31 will be described. More specifically, as shown in FIG. 5, it is assumed that the exposure head 5 is movable in a section 0, a section 1, and a section 2 that are all equidistant at a distance w. As a result, the exposure head 5 can move a total distance of 3w.

  Further, in the following, when N = 6, that is, when six laser diodes 31 of 1ch to 6ch are provided, and formed in each of the six small image areas im1 to im6. A case where the entire exposure image (large image) is recorded with a small image as a constituent part will be described as an example.

  Further, FIG. 5 shows a correspondence relationship (channel-small image region correspondence relationship) between a moving section of the exposure head 5 and a small image region in which a small image is formed by the emission of laser light from each channel. Yes.

  In this embodiment, if all the laser diodes 31 emit light normally, image recording is completed when the exposure head 5 moves only in the section 1. Hereinafter, the section 1 may be referred to as a reference section, and image recording performed in the reference section may be referred to as reference image recording.

  That is, while the exposure head 5 moves in the section 1, the 1ch laser diode 31 is in the small image area im1, the 2ch laser diode 31 is in the small image area im2, and the 3ch laser diode 31 is in the small image area im3. A mode in which the 4ch laser diode 31 performs image recording in the small image area im4, the 5ch laser diode 31 in the small image area im5, and the 6ch laser diode 31 in the small image area im6 corresponds to reference image recording. In other words, with reference image recording, it can be said that image recording performed by the laser diode 31 of each channel in the reference section is performed for small image regions with the same numbers.

  On the other hand, the section 0 and the section 2 are used when the non-light emitting laser diode 31 exists, as will be described later. For example, when the exposure head moves in the section 2, the 1ch laser diode 31 can record an image in the small image area im2, and the 5ch laser diode 31 can record an image in the small image area im6. It has become. Since the section 0 is a section that moves before the exposure head 5 moves in the section 1 that is the reference section, it is referred to as a pre-complementary section, and the section 2 is after the exposure head 5 moves in the section 1 that is the reference section. Since this is a moving section, it may be referred to as a post-complement section. It can also be said that these complementary sections are provided continuously with respect to the reference section before and after the reference section.

(Normal mode)
First, a mode (normal mode) in a state where all the laser diodes 31 provided in the exposure head 5 emit light normally will be described. FIG. 6 is a diagram illustrating the relationship between the head moving section in this case, the light emission / non-light emission state of each of the laser diodes 31 of 1ch to 6ch, and the image recording contents in each ch. In FIG. 6 and the subsequent drawings, an arrow in the item “head movement section” indicates that the exposure head 5 moves in the section, and a cross indicates that the exposure head 5 does not move. Further, in the item to be recorded of each channel, the small image area code im1 and the like enclosed by a square indicates that image recording is performed on the small image area by the laser diode 31 of the channel. The mark indicates that image recording is not performed.

  In this normal mode, since all the channels are in the light emission state, the detection signal for identifying the laser diode 31 in the non-light emission state from the non-light emission detection unit 18 is not given to the main control unit 11. In this case, since only the above-described reference image recording needs to be performed, the channel-specific exposure data generating unit 15 assigns the image recording contents to each channel so that the reference image recording is performed based on the exposure data. Generate exposure data. The main control unit 11 gives predetermined control instructions to the drum drive control unit 13, the head drive control unit 14, and the LD control unit 16 so that image recording is performed according to the channel exposure-specific data. In response to this, each control object is controlled to realize image recording.

(Aspect 1 when there is a non-light-emitting channel)
Next, a processing mode when any one of the laser diodes 31 is in a non-light emitting state (when there is a channel in a non-light emitting state) will be sequentially described for each pattern of the position where the corresponding channel exists.

  In either case, the channel-specific exposure data generation means 15 generates channel exposure-specific data corresponding to each pattern, and the main control means 11 performs drum recording so that image recording according to the channel exposure-specific data is performed. A predetermined control instruction is given to the drive control unit 13, the head drive control unit 14, and the LD control unit 16, and each control unit controls each control object in response thereto, thereby realizing image recording.

  FIG. 7 is a diagram illustrating the relationship between the light emission state of each channel and the image recording content in each channel in the first case. In FIG. 7 and subsequent figures, the small image area where the laser diode 31 of each channel records an image other than the reference section is surrounded by a double line.

  FIG. 7A shows a case where only one even channel (2ch in FIG. 7) is in a non-light emitting state. In this case, image recording is performed using only odd-numbered channels.

  Specifically, the exposure head 5 moves in the sections 1 and 2, and the image recording is performed in two small image areas in which the odd-numbered laser diodes 31 are continuous. That is, in the case shown in FIG. 7A, the 1ch, 3ch, and 5ch laser diodes 31 move to the small image areas im1, im3, and im5 while the exposure head 5 moves in the section 1, which is the reference section. Image recording (reference image recording) is performed, and exposure data for each channel is generated so that image recording is performed in the small image areas im2, im4, and im6 while the exposure head 5 moves in the second complementary section. The means 15 generates channel-specific exposure data. This is because if the channel-specific exposure data generating means 15 is in a normal mode, the contents of image recording in the small image areas im2, im4, and im6 that the 2ch, 4ch, and 6ch laser diodes should bear are 1ch, 3ch, 5ch, This is equivalent to sorting out.

  Strictly speaking, in each section, if the exposure head 5 moves by the distance wy, the image recording corresponding to the section ends. However, in order to move to the next section, the distance y is moved further. It is necessary to reach the start point position of the next section. Hereinafter, for the sake of simplicity, description will be made assuming that image recording is performed by moving the distance w in each section.

  Although illustration is omitted, if only one odd channel is in a non-light emitting state, while the exposure head 5 continuously moves in the section 0 which is the front complement section and the section 1 which is the reference section, It is only necessary to perform image recording in two small image areas where even-numbered laser diodes 31 are continuous.

  Further, as shown in FIGS. 7B and 7C, if the laser diode 31 in the non-light emitting state is only odd-numbered channels or only even-numbered channels, regardless of the number (even if all light is not emitted). ) And image recording can be performed in the same manner as described above.

  That is, as a result of detection by the non-light emission detection means 18, if only even-numbered channels or odd-numbered channels are in a non-light-emitting state, the channel-specific exposure data generation means 15 performs exposure with only odd-numbered channels or even-numbered channels, respectively. In addition, channel-specific exposure data is generated.

  According to the data by channel exposure, the image recording is performed while moving the exposure head not only in the reference section but also in one of the pre-complementary section and the post-complementary section. Even if 31 is present, the image recording process can be continuously performed without stopping the apparatus until the laser diode is replaced.

(Aspect 2 when there is a non-light-emitting channel)
FIG. 8 and FIG. 9 are diagrams illustrating the relationship between the light emission state of each channel and the image recording content in each channel in the second case where there is a non-light emission channel. FIGS. 8 and 9 illustrate a case where even-numbered and odd-numbered laser diodes 31 are mixed in the non-light emitting laser diode 31 and none of them are adjacent to each other.

  In such a case, in principle, the laser diode 31 of the channel in the non-light emitting state is originally (in a normal mode), and the small image region where image recording is to be performed has one channel number smaller than the channel. The laser diode 31 of the channel (adjacent to the left in FIG. 8) performs image recording while the exposure head 5 moves in the section 2 which is the post-complementary section.

  For example, as shown in FIG. 8A, if 2ch and 5ch are in a non-light emitting state, first, a laser of 1ch, 3ch, 4ch, and 6ch while the exposure head 5 moves in the section 1 is used. Image recording is performed in the small image areas im1, im3, im4, and im6 by the diode 31, and the exposure head 5 is continuously moved in the section 2, while the 1ch and 4ch laser diodes 31 are used for the small image areas im2 and im5. Do image recording.

  However, as shown in FIG. 8B, when 1ch is in a non-light-emitting state, this principle cannot be used. In this case, the laser diode 31 of the channel in the non-light-emitting state inherently performs image recording. For the small image area that should be performed, the laser diode 31 of the channel whose channel number is one larger than that channel (the right adjacent in FIG. 8) moves the section 0 where the exposure head 5 is the pre-complement section. During this time, image recording is performed.

  For example, as shown in FIG. 8B, in the case where 1ch and 4ch are in a non-light emitting state, first, the exposure head 5 is moved in the section 0, and a small image is formed by the laser diodes 31 of 2ch and 5ch in the meantime. Image recording is performed in the areas im1 and im4, and the exposure head 5 is subsequently moved in the section 1, while image recording is performed in the small image areas im2, im3, im5, and im6 by the laser diodes 31 of 2ch, 3ch, 5ch, and 6ch, respectively. To do.

  As shown in FIG. 9, when only the channels at both ends of the exposure head 5 such as 1ch and Nch (6ch in FIG. 9) are in a non-light-emitting state, the images of only the left and right adjacent channels are used for both channels. It cannot be recorded. In this case, more exceptionally, first, the exposure head 5 is moved in the section 0 which is the preceding complementary section, and during that time, the 2ch laser diode 31 records an image in the small image area im1, and then the exposure head 5 is sectioned. In the meantime, image recording is performed on the small image areas im2, im3, im4, and im5 by the laser diodes 31 of 2ch, 3ch, 4ch, and 5ch, respectively. Further, the exposure head 5 is also moved in the section 2 which is the post-complementary section, and during that time, the image recording is performed in the small image area im6 by the 5ch laser diode 31.

  In any case, as a result of detection by the non-emission detection means 18, when even-numbered and odd-numbered laser diodes 31 are mixed in the non-light-emitting laser diode 31 and none are adjacent to each other, exposure data for each channel is generated. The means 15 exposes the channel-specific exposure data so that the laser diode 31 of the channel in the non-light-emitting state performs image recording with the laser diode 31 of one of the adjacent channels for the small image region where the image recording should be originally performed. Is generated.

  According to the data by channel exposure, the image is recorded while moving the exposure head not only in the reference interval but also in at least one of the pre-complementary section and the post-complementary section. Even with the diode 31, the image recording process can be continuously performed without stopping the apparatus until the laser diode is replaced.

(Aspect 3 when there is a non-light-emitting channel)
FIGS. 10 and 11 are diagrams illustrating the relationship between the light emission state of each channel and the image recording content in each channel in the third case where there is a non-light emission channel. FIGS. 10 and 11 illustrate a case where even-numbered and odd-numbered laser diodes 31 are mixed in the non-light emitting laser diode 31 and any two channels are adjacent to each other.

  In such a case, the laser diode 31 that is in a non-light-emitting state and that has a non-light-emitting channel next to it is originally (if it is in a normal mode), and for a small image region that is supposed to perform image recording, light emission in the reverse direction The laser diode 31 in the state performs image recording.

  For example, as shown in FIG. 10A, if 2ch and 3ch are in a non-light emitting state, the 1ch and 4ch laser diodes 31 adjacent to each other perform image recording of the small image areas im2 and im3, respectively. To do.

  Specifically, first, the exposure head 5 is moved in the section 0, and during that time, the image recording is performed on the small image area im3 by the 4ch laser diode 31, and then the exposure head 5 is moved in the section 1 while the 1ch, Image recording is performed for each of the small image regions im1, im4, im5, and im6 by the laser diodes 31 of 4ch, 5ch, and 6ch. Further, the exposure head 5 is also moved in the section 2 while the image recording is performed in the small image area im2 by the laser diode 31 of 1ch.

  Similarly, as shown in FIG. 10B, if 3ch and 4ch are in a non-light emitting state, adjacent 2ch and 5ch laser diodes 31 perform image recording on the small image areas im3 and im4. Do each one.

  Specifically, first, the exposure head 5 is moved in the section 0, and during that time, the image recording is performed in the small image area im4 by the 5ch laser diode 31, and then the exposure head 5 is moved in the section 1 while the 1ch, Image recording is performed on each of the small image regions im1, im2, im5, and im6 by the laser diodes 31 of 2ch, 5ch, and 6ch. Further, in the section 2, the exposure head 5 is moved, and in the meantime, the image recording is performed on the small image area im3 by the laser diode 31 of 2ch.

  In addition, as shown in FIGS. 10C, 10D, and 11, in addition to the adjacent non-light emitting channel, there is a non-light emitting channel that has no non-light emitting channel next to it. For the small image area where those channels should originally perform image recording, the same processing as in (Aspect 2) described above may be performed.

  For example, as shown in FIG. 10C, if 5ch is in a non-light emitting state in addition to the adjacent 2ch and 3ch, the 4ch laser diode 31 performs image recording on the small image area im5. .

  Specifically, first, the exposure head 5 is moved in the section 0, and during that time, the image recording is performed on the small image area im3 by the 4ch laser diode 31, and then the exposure head 5 is moved in the section 1 while the 1ch, Image recording is performed on each of the small image regions im1, im4, and im6 by the 4ch and 6ch laser diodes 31. Furthermore, the exposure head 5 is moved also in the section 2, and during that time, the 1ch and 4ch laser diodes 31 perform image recording in the small image areas im2 and im5, respectively.

  As shown in FIG. 10D, when 1ch is in a non-light emitting state in addition to the adjacent 4ch and 5ch, the 2ch laser diode 31 performs image recording on the small image area im1. To do.

  Specifically, first, the exposure head 5 is moved in the section 0, and during that time, the 2ch and 6ch laser diodes 31 perform image recording in the small image areas im1 and im5, respectively, and then the exposure head 5 is moved in the section 1. In the meantime, the image recording is performed for each of the small image areas im2, im3, and im6 by the laser diodes 31 of 2ch, 3ch, and 6ch. Further, the exposure head 5 is also moved in the section 2 while the image recording is performed in the small image area im4 by the laser diode 31 of 3ch.

  Furthermore, as shown in FIG. 11, when two adjacent channels (3ch, 4ch) are in a non-light emitting state, and channels (1ch, 6ch = Nch) at both ends of the exposure head 5 are also in a non-light emitting state. First, the exposure head 5 is moved in the section 0, and during that time, the 2ch and 5ch laser diodes 31 respectively record the images in the small image areas im1 and im4, and then the exposure head 5 is moved in the section 1 during the same. Image recording is performed for each of the small image regions im2 and im5 by the laser diodes 31 of 2ch and 5ch. Further, the exposure head 5 is also moved in the section 2 and during that time, the image recording is performed in the small image areas im3 and im6 by the laser diode 31 of 2ch and 5ch three times.

  In any case, as a result of detection by the non-emission detection means 18, when the even-numbered and odd-numbered laser diodes 31 are mixed in the non-light-emitting laser diode 31 and any two channels are adjacent, the channel The separate exposure data generating means 15 sets the reverse light emission state for the small image region where the laser diode 31 that is in the non-light-emitting state and has the non-light-emitting channel next to the original image recording should be used. Channel-specific exposure data is generated so that a laser diode 31 performs image recording.

  Further, in addition to the adjacent non-light emitting channel, when there is a non-light emitting channel that does not have a non-light emitting channel next to the channel, the channel is processed so as to perform the same processing as in the above (Aspect 2). Separate exposure data is generated.

  According to the data by channel exposure, the image recording is performed while moving the exposure head not only in the reference interval but also in both the pre-complementary section and the post-complementary section, so that the laser diode in the non-light emitting state with the position pattern as described above Even if 31 is present, the image recording process can be continuously performed without stopping the apparatus until the laser diode is replaced.

(Modification of aspect 3)
When channels in a non-light emitting state are detected in a pattern as shown in FIGS. 10A and 10B, it is possible to perform image recording using only a smaller number of channels. FIG. 12 is a diagram for explaining this.

  FIG. 12A shows a different image recording process when 2ch and 3ch are detected as non-light-emitting states, as in FIG. 10A.

  Specifically, first, the exposure head 5 is moved in the section 0, and during that time, the image recording is performed on the small image area im3 by the 4ch laser diode 31, and then the exposure head 5 is moved in the section 1 while the 1ch, Reference image recording is performed by the laser diodes 31 of 4ch and 6ch. Further, the exposure head 5 is also moved in the section 2 while image recording is performed on the small image areas im2 and im5 by the 1ch and 4ch laser diodes 31 in the meantime.

  In this case, it is different from FIG. 10A in that the 5ch laser diode 31 that can be used for image recording is not used. The example of FIG. 12A uses the fact that the exposure head 5 also needs to move in the section 2 that is the post-complementary section in order for 1ch to record an image on the small image area im2. The 4ch laser diode 31 that recorded the images on the small image areas im3 and im4 while moving in 0 and the section 1 was also used for forming the small image area im5 in the section 2 as it is.

  Similarly, FIG. 12B shows a different image recording process when 3ch and 4ch are detected as non-light-emitting states, as in FIG. 10B.

  Specifically, first, the exposure head 5 is moved in the section 0, and during that time, image recording is performed in the small image area im4 by the laser diode 31 of 5ch, and then the exposure head 5 is moved in the section 1 while Reference image recording is performed by laser diodes 31 of 2ch and 5ch. Further, the exposure head 5 is also moved in the section 2 while the image recording is performed on the small image areas im3 and im6 by the laser diodes 31 of 2ch and 5ch.

  In this case, the 6ch laser diode 31 that can be used for image recording is not used, which is different from FIG. The example of FIG. 12B uses the fact that the exposure head 5 must also move in the section 2 that is the post-complementary section in order for 2ch to perform image recording on the small image area im3. The 5ch laser diode 31 used for image recording on the small image areas im4 and im5 while moving in 0 and section 1 is also used for forming in the small image area im6 in section 2 as it is.

  In these embodiments, the movement distance of the exposure head 5 is the same as in FIGS. 10A and 10B, but there is an advantage that the number of laser diodes 31 to be emitted is small.

(When image recording cannot be continued)
As described above, even when two non-light emitting channels are adjacent to each other, image recording can be performed by using the laser diodes 31 of the light emitting channels adjacent to each other. In other words, in the present embodiment, image recording cannot be performed only when three or more channels are adjacent and enter a non-light emitting state. However, exceptionally, at both ends of the exposure head 5, image recording cannot be performed even if two channels are adjacent to each other.

  However, the appearance of the non-light-emitting state in such a manner is actually a very rare case in a CTP apparatus including laser diodes on the order of several tens to one hundred. Therefore, according to the present embodiment, Even if a channel that is in a non-light emitting state is generated in a normal use mode, image recording can be continued in any of the above modes.

<Second Embodiment>
In the first embodiment described above, it is assumed that image recording is performed with section 1 as a reference section, but the mode of image recording in CTP device 100 is not limited to this.

  FIG. 13 is a diagram showing the relationship between the head movement section, the light emission / non-light emission state of the laser diode 31 of each channel, and the image recording contents of each channel in the normal mode of the present embodiment.

  That is, in the CTP apparatus 100 according to the present embodiment, the movable range of the exposure head 5 is determined so that the exposure head 5 moves only in the section 0 and performs image recording in the normal mode. Shall. That is, it is assumed that the section 0 is set as the reference section, and the image recording performed while the exposure head 5 moves in the section 0 is the reference image recording. Therefore, section 1 and section 2 are post-complementary sections.

  FIG. 14 is a diagram illustrating the relationship between the light emission state of each channel and the image recording content in each channel when there is a non-light emission channel in the present embodiment.

  In the present embodiment, in principle, when there is a non-light emitting channel, the number of channels is smaller than that channel, and the laser diode of the nearest channel is the image of the laser diode of the non-light emitting channel. The exposure data for each channel is generated so that the image recording is performed on the small image area to be recorded.

  For example, in the case shown in FIG. 14A, since 2ch is in a non-light emitting state, the 1ch, 3ch, 4ch, 5ch, and 6ch lasers are moved while the exposure head moves in the section 0 which is the reference section. After each of the diodes 31 performs the standard image recording, the exposure head 5 is further moved in the section 1 which is the post-complementary section, and the 1ch laser diode having one channel number smaller than 2ch is recorded in the small image area im2. To do.

  Further, in the case shown in FIG. 14B, since 3ch and 5ch are in the non-light emitting state, the 1ch, 2ch, 4ch, and 6ch of the 1ch, 2ch, 4ch, and 6ch while the exposure head moves in the reference section 0. After the laser diode 31 performs the reference image recording, the exposure head 5 is further moved in the post-complementing section 1 so that the 2ch and 4ch laser diodes perform image recording in the small image areas im3 and im5, respectively. To.

  Alternatively, in the case shown in FIG. 14 (c), 5ch and 6ch are adjacent to each other and are in a non-light emitting state, so that the 1ch, 2ch, 3ch while the exposure head moves in the reference section 0. After the 4ch laser diode 31 has recorded the reference image, the exposure head 5 is further moved in the post-complementary section 1 and also in the section 2, and the images of the small image areas im5 and im6 are transferred to the 4ch laser diode. Make recordings continuous. In the present embodiment, since there are two post-complementary sections, section 1 and section 2, image recording in this manner can be performed.

  That is, also in this embodiment, image recording can be performed even when two non-light emitting channels are adjacent to each other. In the present embodiment, image recording cannot be performed, as a general rule, only when three or more channels are adjacent and enter a non-light emitting state. However, exceptionally, even if 1ch is in a non-light emitting state, image recording cannot be performed.

  However, the appearance of the non-light-emitting state in this manner is a very rare case in an actual CTP device. Therefore, even in this embodiment, there are channels that do not emit light in the normal usage state. Even if it occurs, image recording can be continued according to any one of the above embodiments.

<Third Embodiment>
In the first embodiment described above, the exposure head 5 moves within the range of three sections (distance 3w) of section 0, section 1, and section 2, and section 1 is set as a reference section. Although it is assumed that image recording is performed, the movement mode of the exposure head 5 in the CTP apparatus 100 is not limited to this.

  FIG. 15 is a diagram showing the relationship between the head movement section, the light emission / non-light emission state of the laser diode 31 of each channel, and the image recording contents of each channel in the normal mode of the present embodiment.

  As shown in FIG. 15, in the CTP device 100 according to the present embodiment, the point that image recording is performed using the section 1 as a reference section is the same as that of the first embodiment. The difference is that a section 3 is further provided at the end of 2. That is, in the CTP apparatus 100 according to the present embodiment, k = 4, that is, the exposure head 5 moves within the range of the distance 4w.

  As described above, also in the present embodiment, since section 1 is set as a reference section, and section 0 and section 2 are included, as in the first embodiment, an image using only these sections is used. Recording is possible. Therefore, the description about them is omitted.

  FIG. 16 is a diagram illustrating the relationship between the light emission state of each channel and the image recording contents in each channel when there is a non-light emission channel with a pattern characteristic of the present embodiment.

  First, FIG. 16A shows a case where a non-light-emitting channel exists in the same pattern as in FIG. 10C in the first embodiment.

  In the present embodiment, when two adjacent channels are in a non-light-emitting state as shown in FIG. 16A (2ch and 3ch in FIG. 16A), the number of channels is smaller than these and the nearest channel is present. The channel-specific exposure data is set so that the laser diode 31 of the channel (1ch in FIG. 16A) performs image recording on the small image region where the laser diode of the non-light emitting channel should originally perform image recording. To be generated.

  In the example shown in FIG. 16A, in addition to 2ch and 3ch, 5ch is also in a non-light emitting state, so that the laser diodes of 1ch and 4ch are moved while the exposure head is moving in the section 1, which is the reference section. After each 31 performs the reference image recording, the exposure head 5 is further moved in the post-complementary section 2 and also in the section 3, and the image recording of the small image areas im2 and im3 is continuously performed on the 1ch laser diode. The image recording of the small image areas im5 and im6 is continuously performed by the 4ch laser diode.

  In the example shown in FIG. 16A, since 6ch is in a light emitting state, reference image recording may be performed for 6ch, but in the first place, the exposure head is used to perform image recording of the small image area im3 in 1ch. 5 needs to be moved in the section 3, and the moving distance of the exposure head 5 does not change regardless of the use of 6ch. Therefore, the embodiment shown in FIG. It can be said.

  In the present embodiment, image recording can be performed even when three non-light-emitting channels continue, which could not be recorded in the first embodiment. FIGS. 16B and 16C show this.

  In such a case, among the three consecutive non-light emitting channels, the laser diode 31 of the two channels with the smaller number of channels originally has a smaller number of channels than those for a small image region where image recording is to be performed. The laser diode 31 of the latest channel performs image recording. Furthermore, the remaining one of the non-light emitting channel laser diodes 31 having the largest number of channels is originally a channel having one channel number larger than that of the non-light emitting channel for the small image region to be recorded. The laser diode 31 performs image recording.

  In the example shown in FIG. 16B, 2ch, 3ch, and 4ch are in a non-light emitting state continuously, so that the 1ch laser diode records the small image areas im2 and im3, and the 5ch laser diode Image recording of the small image area im4 is performed.

  Specifically, first, while the exposure head is moving in the section 0, the 5ch laser diode 31 records an image in the small image area im4, and then the exposure head 5 is moved in the section 1, which is the reference section. During this time, the 1ch and 5ch laser diodes 31 perform reference image recording. Further, the exposure head 5 is further moved in the post-complementary section 2 and also in the section 3, and the 1ch laser diode continuously records the small image areas im2 and im3, and the 5ch laser diode is small. Image recording of the image area im6 is performed.

  In the example shown in FIG. 16C, 3ch, 4ch, and 5ch are continuously in a non-light emitting state, so the 2ch laser diode performs image recording of the small image areas im3 and im4, and the 6ch laser diode Image recording of the small image area im5 is performed.

  Specifically, first, while the exposure head is moving in the section 0, the 2ch and 6ch laser diodes 31 perform image recording of the small image areas im1 and im5, and subsequently the section 1 which is the reference section is exposed to the exposure head. While 5 is moving, laser diodes 31 of 2ch and 6ch respectively perform reference image recording. Further, the exposure head 5 is further moved in the post-complementary section 2 and further in the section 3, and the image recording of the small image areas im3 and im4 is continuously performed by the 2ch laser diode.

  That is, in this embodiment, even when three non-light emitting channels are adjacent, image recording is performed by using the laser diodes 31 of the light emitting channels adjacent to both ends thereof. I can do it. In other words, in the present embodiment, image recording cannot be performed only when four or more channels are adjacent and enter a non-light emitting state. However, exceptionally, even if both 1ch and 2ch are not emitting light, image recording cannot be performed.

  However, the appearance of the non-light-emitting state in such a manner is actually a very rare case in a CTP apparatus including laser diodes on the order of several tens to one hundred. Therefore, according to the present embodiment, Even if a channel that is in a non-light emitting state is generated in a normal use mode, image recording can be continued in any of the above modes.

<Modification>
In the above-described embodiment, the non-light emission detection means 18 determines the non-light emission state based on the current value of the operation current. Instead, a photodiode is provided in each LD unit 30, and the photodiode is A mode in which the non-light emitting state is determined based on the detected light quantity value may be used.

  Alternatively, instead of the mode in which the non-emission detection means 18 detects the non-emission state, each emission state is visually monitored or inspected while a predetermined operation current is applied to each laser diode, and the result is illustrated. Alternatively, it may be applied to the main control means 11 by a predetermined input means, and the channel-specific exposure data is generated based on this.

  In the above-described embodiment, the printing plate P provided on the surface of the drum 1 is an object to be exposed. Instead, the surface of the drum 1 itself is an object to be exposed and an image formed on the surface is formed. May be formed such that an image can be formed by being transferred to a predetermined transfer object.

  It should be noted that the loading / unloading of the printing plate P to / from the CTP device 100 and the attachment / detachment of the printing plate P to / from the drum 1 may be performed by a predetermined device (not shown). In such a case, a control means for controlling these processes is also provided separately.

DESCRIPTION OF SYMBOLS 1 Drum 3 Head moving ball screw 4 Head moving motor 5 Exposure head 6 Drum drive means 11 Main control means 12 Exposure data input means 13 Drum drive control means 14 Head drive control means 15 Channel-specific exposure data generation means 16 LD control means 17 LD drive means 18 Non-emission detection means 30 LD unit 31 Laser diode 100 CTP device AX Rotating axis IM Exposure image P Printing plate

Claims (5)

An exposure apparatus for exposing an object to be exposed,
A holding body for holding an object to be exposed;
A plurality of light sources capable of emitting exposure light simultaneously;
An exposure head in which the plurality of light sources are discretely arranged at equal intervals in the arrangement direction along the object to be exposed;
Moving means for moving the exposure head along the object to be exposed;
Exposure data input means for acquiring overall exposure data describing the contents of exposure on the object to be exposed;
Channel-specific exposure data generating means for generating channel-specific exposure data that describes the exposure content in each of the plurality of light sources based on the overall exposure data;
Exposure control means for controlling the plurality of light sources so as to emit exposure light in accordance with the description content of the exposure data for each channel;
With
When all of the plurality of light sources are in a light emitting state, the channel-specific exposure data is generated so as to form the exposed area using the exposure light emitted from all of the plurality of light sources, The exposure control means performs exposure from the plurality of light sources in accordance with the channel-specific exposure data while moving the exposure head only between reference intervals having a distance that substantially matches the interval between the plurality of light sources in the arrangement direction by the moving means. Forming the exposed area by emitting light for use,
In the arrangement direction, in addition to the reference section, in the case where only the odd-numbered light source in the arrangement direction or only the even-numbered light source in the arrangement order is the non-light emitting state among the plurality of light sources , In the non-light-emitting state, the exposure head is moved even in the complementary section that is continuously provided in the reference section in at least one of the front and rear of the reference section and has a natural number times the reference section. The exposure data for each channel is generated so as to form the exposed area using the exposure light from the light source having the opposite evenness in the arrangement order of the light source, and in the reference section and the supplementary section by the moving means while moving the exposure head, light source and even the exposure control means is in the non-emission state in accordance with the channel-by-channel exposure data There is formed the area to be exposed by emitting the exposure light from the opposite light source,
An exposure apparatus characterized by that. The exposure apparatus according to claim 1,
Non-emission detection means for detecting that the plurality of light sources are in a non-emission state;
Further comprising
On the basis of the detected content of the non-light emitting detection means, and the light source to use for the exposure and the moving range of the exposure head is determined,
An exposure apparatus characterized by that. In the exposure apparatus according to claim 1 or 2 ,
Light source in the non-emission state of the previous SL plurality of light sources, and a the arrangement order is an even-numbered light source and the odd-numbered source in the arrangement direction, and none of the light source in the the non-emission state said In the case where the light sources in the non-light emitting state are supposed to be exposed when they are not adjacent to each other in the arrangement direction, the light sources in the non-light emitting state while the exposure head is moving in the complementary section The channel-specific exposure data is generated so that exposure is performed by any one of the light sources adjacent to the channel.
An exposure apparatus characterized by that. The exposure apparatus according to any one of claims 1 to 3 ,
Light source in the non-light emitting state, and a the arrangement order is an even-numbered light source and the odd-numbered source in the arrangement direction, and, adjacent in any two of the arrangement direction of the light source in the the non-emission state If you are, the originally adjacent light source in the non-emission state, the region to be subjected to exposure is close to the light source in each of the non-emission state while the exposure head is moved to the complementary section as the light emitting state of the light source to perform exposure for the channel-by-channel exposure data is generated,
An exposure apparatus characterized by that. The exposure apparatus according to any one of claims 1 to 4 ,
After the reference section, the supplementary section having a distance of at least twice the reference section is provided .
An exposure apparatus characterized by that.

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