JPH09118002A - Laser printing plate engraving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size and weight of a laser block by providing a fixed semiconductor laser part having at least a semiconductor laser, an imaging optical system part moving corresponding to a laser beam emitted position, and an optical fiber for coupling the laser part to the optical system part. SOLUTION: A semiconductor laser part 31 is connected to one end of an optical fiber 72 through an optical fiber connector 71-1. The other end of the fiber 72 is connected to the focusing optical system part 30 through an optical fiber connector 71-2, and the length of the fiber 72 is formed longer than the width of a printing plate in the axial direction of a plate cylinder. Since only a laser block having the optical system may be mounted at the laser moving stage 28 of the semiconductor laser and optical system, the size and weight of the moving part can be reduced. The problem of the inertia at the time of moving is substantially eliminated by the reduction of the weight of the moving part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser plate making apparatus for producing a printing plate used for gravure printing.

[0002]

[Prior art]

[Laser Plate Making Apparatus] First, general items of the laser plate making apparatus related to the present invention will be described. The laser plate making device is also called an electronic gravure system plate making device, and is a device for creating a printing plate (intaglio) used at the time of gravure printing.

Conventionally, in gravure printing, a metal plate is used as a printing plate (intaglio plate) used for printing, and the metal plate sheet is made up of a set of minute recesses by photolithography of the image density and the etching technique. A two-dimensional halftone image plate was formed. In the next printing stage, the printing plate is dipped in an ink reservoir, and then excess ink is scraped off and pressed onto the paper surface to complete printing. Gravure printing is widely used because it can easily print hundreds to thousands of sheets.

In recent years, an electronic gravure technique using a resin sheet as a printing plate has been put into practical use. This laser plate making apparatus is an apparatus as shown in FIG. 4, which uses a laser beam to form recesses corresponding to the light and shade of an image on a resin sheet of a printing plate. The resin sheet of the printing plate has a surface layer coated with a thermoplastic resin such as modified polyester.

As shown in FIG. 4, the laser plate making apparatus generally comprises a plate body 1 which is driven to rotate about an axis 4 (in the direction A or B) as a main scanning unit, a semiconductor laser and an optical system. The laser block units 10 and 21 and the sub-scanning unit that linearly drives the laser block units 10 and 21 in the axial direction of the plate cylinder 1 (in the C direction or the D direction) are provided. A resin sheet 2, which is a workpiece, is wound around the plate body 1.

The main scanning unit comprises a plate cylinder unit 1, a plate cylinder rotation driving motor 7, and the like. The plate cylinder 1 is drivingly connected to a plate cylinder rotation driving motor 7 via a plurality of timing belts 5 and a plurality of pulleys 6, and is rotationally driven in the A direction or the B direction.

The laser block section has a semiconductor laser 10 for emitting a laser beam and a laser optical system 21 for focusing the laser beam on a resin sheet (workpiece) 2.

The sub-scanning portion is connected to a laser block moving motor 24 and a rotor (not shown) of the motor 24, and is bridged in the axial direction of the plate body portion 1 between bearing portions 23R and 23L. The ball screw 26, the moving element 27 screwed to the ball screw 26, etc., and the laser block moving motor 24 rotationally drives the ball screw 26, and the rotational movement of the ball screw 26 is converted into the linear movement of the moving element 27. The laser blocks 10 and 21 (on the moving stage 28) connected to the linearly moving mover 27 via an arm 29.
Moves along a trajectory defined by two rails 22 in a very precise manner in parallel to the axial direction (direction C or D).

FIG. 5 is a block diagram of the main functions of the laser plate making apparatus of FIG. 4, and the operation of the laser plate making apparatus will be described using this.

The microcomputer (CPU) 32 is
Controls the operation of the entire laser plate making device. Image data of an image to be printed is stored in a data RAM 38 connected to the CPU 32. For example, for color printing,
C (cyan), M (magenta), Y (yellow), BK
(Black) different digital image data and the like.

Gamma table 4 connected to the CPU 32
Reference numeral 2 is a non-linear conversion table stored in, for example, a ROM. The CPU 32 compares the image data 40 stored in the data RAM 38 with the gamma table 42, and determines the concave portion having a shape corresponding to the image data 40 to the resin sheet 2
The value of the output relationship between the laser intensity and the emission time required for forming the above is determined. For color printing, C (cyan),
The value of the output relationship between the laser intensity and the light emission time of each pixel of each of the M (magenta) and Y (yellow) printing plates is determined. If necessary, B (black) printing plate data is also included.

A rotation control signal is sent from a microcomputer (CPU) 32 to a plate cylinder rotation driver (plate cylinder rotation drive device) 35. From the rotation control signal, the plate cylinder rotation driver 35 drives the plate cylinder rotation motor. A driving pulse signal is sent to 7, and the plate cylinder 1 rotates stepwise in synchronization with this driving pulse. On the other hand, the CPU 32 determines the laser intensity and the light emission time according to the gamma table 42 from the image data stored in the data RAM 38, and sends this data to the laser driver (laser driving device) 43.

The laser driver 43 sends a pulse signal corresponding to this data to the semiconductor laser 10 to cause the semiconductor laser 10 to emit light in synchronism with the drive pulse of the plate cylinder rotating motor 7, and the irradiation spot on the resin sheet 2 is irradiated. The resin is melted and scattered and sublimated to form a predetermined recess on the resin sheet 2. The semiconductor laser 10 sequentially forms recesses corresponding to image data along the circumference of the resin sheet 2 wound around the plate cylinder 1. The spot shape of the laser is typically a square shape of about 50 [micron], and the depth of the concave portion formed on the resin sheet is 5 to 6 [micron], which is irradiated according to the gradation of the image. .

A recess corresponding to the image is formed until the plate cylinder 1 makes one rotation, and the laser block 1 is synchronized with the end of one rotation.
A motor driver 33 for moving the laser block transmits a movement control signal for moving 0, 21 in the axial direction of the plate cylinder 1 by one pixel.
To drive the laser block moving motor 24 to move the laser block 21.

In this way, while rotating the plate cylinder 1 to form a concave portion for one rotation, and thereafter, the operation of moving the laser blocks 10 and 21 by one pixel is repeated to form an image on the resin sheet 2 having a predetermined area. To form a concave portion corresponding to.

As described above, the laser plate making apparatus radiates the semiconductor laser 10 while synchronizing the rotation of the plate cylinder 1 by the plate cylinder rotating motor 35 and the linear movement of the laser block 21 by the laser block moving motor 24. This is an apparatus for forming a set of concave portions corresponding to the image data 38 on the resin sheet 2.

FIG. 6 is a view showing a main part of a laser plate making apparatus using a 2 W semiconductor laser having a higher output.
In the laser plate making apparatus using the semiconductor laser having an output of 1 W shown in FIG. 4, natural air cooling is sufficient for cooling the semiconductor laser. However, as shown in FIG. 6, when a semiconductor laser having a higher output of 2 [W] is used, it is necessary to attach a semiconductor cooling device (heat sink) 70 to the semiconductor laser in order to forcibly cool it. Become.

Actually, for example, when a near infrared laser diode model SLD324 with a light output of 2000 mW manufactured by Sony Corporation, which is the applicant of the present invention, is used as a heat sink attached to this model model APF6020 manufactured by Daiei Seiki Co., Ltd.
You are using This heat sink has an external shape of □ 60.
mm × H20mm, with 1,7 pins on the rectangular heat sink
Forty of them are implanted, and a fan motor is installed at the tip of the pin to blow air to the pin.

FIG. 7 is a diagram showing an actual configuration of such a laser block. The laser block unit includes the semiconductor laser 10 and the optical system 21. The optical system 21 includes a collimator lens 5 arranged adjacent to the semiconductor laser 10.
0, an anamorphic prism 51, an objective lens 52, and a cover glass (CG) 53 are sequentially arranged along the optical axis.

A laser beam is emitted from the semiconductor laser 10. A semiconductor laser cooling device (heat sink) 70 for cooling the semiconductor laser 10 is attached to the back surface side of the semiconductor laser 10 to cool the semiconductor laser 10 during operation.

The laser beam from the semiconductor laser 10 is collimated by the collimator lens 50 into light parallel to the optical axis. The laser beam made into this parallel light is beam-shaped by the anamorphic prism 51. For this reason,
The anamorphic prism 5 has two triangular prisms in order to independently change the image magnification in the horizontal and vertical directions along the optical axis.

The laser beam emitted from the anamorphic prism is focused by the objective lens 52, passes through the cover lens 53, and a desired image is formed on the resin sheet (not shown) wound around the plate body 1. To tie.

With such an optical system, the semiconductor laser 10 is held by the LD (laser diode) holder 61, the collimator lens 50 is held by the collimator lens holder 62, and the anamorphic prism 51 is held by the anamorphic prism holder 63. The objective lens 52 is held by the objective lens holder 64.

[Multi-Beam Type Laser Plate Making Apparatus] The laser beam currently used in the laser plate making apparatus is
It is a single laser beam source (single beam), and requires an average working time of 40 minutes to form a recess on an A3 size printing plate, for example. Therefore, as one of the shortening of the plate making time, the applicant of the present application has already proposed a multi-beam type laser plate making apparatus in which a plurality of laser sources are arranged around the plate cylinder in the circumferential direction or the rotation axis direction.

FIG. 8 is a diagram showing the overall construction of a multi-beam type laser plate making apparatus already proposed by the applicant of the present application. In the multi-beam method shown in FIG. 8, four laser blocks 10A and 21A, 10B and 21B, 10C and 21C, 10D and 21D are fixed on the same laser block mounting base 28 and are integrated along the rail 22. Are moving. Here, the laser blocks 10A and 21A are a partial area A of the plate-making area of the resin sheet 2, the laser blocks 10B and 21B are areas B, the laser blocks 10C and 21C are areas C, and the laser blocks 10D and 21D are The regions D are respectively configured to form the recesses. This multi-beam method reduces the plate making area of each laser beam source and is effective for shortening the plate making time.

[0026]

As described with reference to FIG. 6, the semiconductor laser cooling device 70, the semiconductor laser 10 and the laser optical system 21 are integrally attached to the moving stage 28 in the laser block portion. There is.

Therefore, the laser block moving motor 7
Since the laser block portion which is linearly moved by the ball screw 26 connected to is large in size and heavy in weight, there is a problem that the motion inertia during movement is large and accurate positioning becomes difficult. Further, since the size of the laser block becomes large and occupies a large space, there arises a problem that the degree of freedom around the plate cylinder is small in designing.

Further, even when the number of semiconductor lasers as shown in FIG. 8 is increased to form a multi-beam, a certain limitation occurs due to the size of the laser block portion being considerably large. For example, in a typical example, when the dimension of the plate in the sub-scanning direction (width direction) is about 318 mm, the width dimension of the laser block is about 50 mm, so that the number of beams is limited to 6 beams due to space limitations ( 318 mm / 50
mm = 6).

In the future, it is planned to use a semiconductor laser having a higher output in order to reduce the plate making time. However, in response to the increase in the output of the semiconductor laser 10, a semiconductor laser cooling device 70 having a larger weight and a larger size is provided. This is required, which further increases the size and weight of the laser blocks 70, 10, 21.

Next, in the conventional semiconductor laser plate making apparatus, the stripes of the semiconductor laser are directly imaged on the resin sheet on the printing plate to form a striped spot shape corresponding to the light emitting stripes. In a semiconductor laser, the emission stripe width generally increases with the output. For example, a near infrared laser diode manufactured by Sony Corporation, each having a line width of about 1 μm, and having an output of 1 [W], model number SILD
The emission stripe width of 323 (corresponding to the length of the stripe, but generally referred to as "stripe width") is 100.
[Μm], output 2 [W] model number SILD324 is 200
[Μm], output 3 [W] model number SILD325 is 500
As in [μm], the higher the output, the larger the emission stripe width.

On the other hand, in order to form the concave portion with the same precision as the conventional one on the resin sheet, it is necessary to realize the same focal stripe width as the conventional one on the resin sheet. Therefore, the laser beam having a large emission stripe width must be corrected by the optical system at the subsequent stage, and the optical system is inevitably changed.

As the stripe width of the laser beam emitted from the semiconductor laser increases, the ineffective beam increases and it becomes more difficult to narrow the focal stripe width. Therefore, in order to obtain a predetermined coupling efficiency, A lens with a large NA value (that is, a bright lens)
An optical system using is required.

Here, the coupling efficiency means the ratio of the effective laser beam. In practice, a computer simulation is used to draw the laser beam flow from the emission of the semiconductor laser to the image formation on the resin sheet by computer simulation. The ratio of the light amount of the imaging laser beam to the light amount of the emitted laser beam is calculated as a percentage.

NA (numerical aperture) is also called a numerical aperture, and is one of the quantities representing the optical performance relating to the brightness and resolving power of an optical system including a lens, etc., and is a light beam entering or exiting an optical system or an optical element. It is represented by a half-angle sine of the maximum cone angle of the bundle. NA = n · sin α where n: refractive index of medium in object space (usually 1 in air) α: half-angle of maximum cone angle in medium in object space

For example, in the conventional optical system shown in FIG. 7, the semiconductor laser 10 has an output of 2 [W] (model number SLD324).
Is used, the emission stripe width is 200 μm.
In order to make this the same focal stripe width as the conventional one, 66.7 μm, each school element of the optical system has the following specifications.

Optical element characteristic value Collimator lens 50 Focal length f1 = 4.5 mm, NA0.53 Anamorphic prism 51 Magnification m = 6 times Objective lens 52 Focal length f2 = 9.0 mm, NA0.50

In the optical system of FIG. 7, the following equation holds as the relationship between the emission stripe width and the focal stripe width of the semiconductor laser 10. (Focus stripe width) / (Light emission stripe width) = (f2 / f1) × (1 / m) (1)

Further, the coupling efficiency of this optical system (using a semiconductor laser model number SLD324 having an output of 2 [W]) is 95.2% when obtained by simulation.

When the semiconductor laser having an output of 2 [W] is changed to a semiconductor laser having an output of 3 [W] (model number SLD325), the emission spectrum width is 200 μm to 500 μm.
In order to achieve the same focal stripe width of 66.7 μm as before, it is necessary to change the optical system.

Here, the collimator lens 50 and the anamorphic prism 51 are the same as the conventional ones, and only the objective lens is changed so that the change can be minimized when changing the optical system. And In order to realize the same focal stripe width of 66.7 μm as in the conventional case, the required specification of the focal length f2 of the objective lens is as follows from the formula (1). Focal length f2 = (focus stripe width x f1 x anamorphic prism magnification) / (light emission stripe width) = (66.7 µm x 4.5 x 6) / 500 µm = 3.6 mm

With respect to the optical system incorporating the objective lens with the focal length f2 = 3.6 mm, the coupling efficiency is obtained by simulating the objective lens with various NAs, and the following results are obtained. To be

Semiconductor objective lens Laser focal length of objective lens NA (numerical aperture) Coupling efficiency Power increase rate 3W 3.6mm 0.5 46.9% 0.76 ^{* 1} 3W 3.6mm 0.7 72.5% 1.14 ^{* 2} 3W 3.6mm 0.9 87.5% 1.38 ^{* 3}

Note) Calculation of power increase rate * 1 ... 0.76 = (3W × 46.9%) / (2W × 95.2%) * 2 ... 1.14 = (3W × 72.5%) / (2W × 95.2%) * 3 ... 1.38 = (3W × 87.5%) / (2W × 95.2%)

A description will be added to the above table. At present, the maximum objective lens used in optical disk drive devices is about 0.5. When one lens is used, NA 0.5 is the brightest lens. Further, a 0.7 lens having a larger NA is conventionally used in a microscope or the like, but it is difficult to form one lens, and a plurality of combined lenses is used. Furthermore, if the lens has an NA of 0.9, the number of combined lenses will increase, and the total thickness of the lenses will increase, and the weight will increase accordingly. When the weight becomes heavy, it cannot be actually used as a laser block for a laser plate making device.

Further, in the objective lens having NA of about 0.5, the power increase rate is 0.74 times, which is actually decreased, and the laser output is not increased. However, as the NA increases, it becomes difficult to manufacture the lens itself, and the manufacturing cost also increases. A lens having a large NA is a combination of a plurality of lenses, and the size and size increase, which makes it unsuitable as a laser block for a laser plate making apparatus.

Further, a semiconductor laser or the like in which the output stripe profile of the semiconductor laser was changed to be arranged in an array to increase the output was examined, but it could not be used in principle.

In view of the above problems, it is an object of the present invention to reduce the size and weight of a laser block in a laser plate making apparatus.

A further object of the present invention is to provide a laser plate making apparatus to which a semiconductor laser cooling device having a high cooling capacity can be easily attached as the output power of the semiconductor laser increases.

A further object of the present invention is to provide a laser plate making apparatus capable of easily increasing the number of beams when adopting the multi-beam method.

[0050]

A laser plate making apparatus according to the present invention comprises a fixed semiconductor laser portion having at least a semiconductor laser, an imaging optical system portion which moves corresponding to a laser beam irradiation position, and An optical fiber for connecting the semiconductor laser portion and the image forming optical system portion is provided. In this case, a semiconductor laser cooling device can be attached to the semiconductor laser.

Further, the laser plate making apparatus according to the present invention adopts a multi-beam method, and includes a plurality of fixed semiconductor laser portions each having at least a semiconductor laser,
A plurality of image forming optical system portions provided corresponding to the plurality of semiconductor laser portions and moving corresponding to the laser beam irradiation location, and each of the semiconductor laser portions and the image forming corresponding thereto. And a plurality of optical fibers for respectively coupling the optical system part. In this case, a semiconductor laser cooling device may be attached to each of the semiconductor lasers.

In the laser plate making apparatus of the present invention, only the image forming optical system portion of the laser beam is arranged as the moving portion, and the semiconductor laser portion is separately arranged, so that the moving portion can be made compact and lightweight. Since the semiconductor laser part does not exist in the moving part, it is not limited in size and weight,
If desired, a semiconductor laser cooling device with higher performance can be attached to the semiconductor laser.

[0053]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a laser plate making apparatus and a plate making method which are suitable for applying the present invention will be described below with reference to the accompanying drawings. The same elements will be denoted by the same reference symbols, without redundant description.

[One Embodiment of Laser Plate Making Apparatus] FIG. 1 is a diagram showing a main part of a laser plate making apparatus according to this embodiment.
This embodiment is characterized in that the laser block of the conventional laser plate making apparatus is separated into a semiconductor laser portion 31 and an optical system portion 30 for focusing a laser beam, and both portions are coupled by an optical fiber 72. .

As shown in the figure, a ball screw 26 is drivingly connected to the laser block moving motor 24. A mover 27 is screwed onto the ball screw 26,
It moves linearly in the C direction or the D direction by the rotational movement of. The moving stage 28 is connected to the mover 28. Of the conventional laser block, only the imaging optical system portion 30 is fixed to the moving stage 28. The image forming optical system portion 30 includes a collimator lens, an objective lens, an objective lens, and the like.

On the other hand, the remaining semiconductor laser portion 31 does not exist on the moving stage 28 but is arranged at the end of the rail 22, for example. The semiconductor laser portion 31 includes the semiconductor laser 10 and the semiconductor laser cooling device 70. The semiconductor laser 10 includes the semiconductor laser cooling device 7 and the like.
It is hidden behind 0 and does not appear in the figure.

This semiconductor laser portion 31 is connected to one end of an optical fiber 72 via an optical fiber connector 70-1. The other end of the optical fiber 72 is connected to the imaging optical system portion 30 via an optical fiber connector 71-2.
The length of the optical fiber 72 is longer than the plate-making width in the axial direction of the plate cylinder.

FIG. 2 (1) is a diagram showing details of the semiconductor laser portion 31 and the imaging optical system portion 30, and FIG.
FIG. 3 is a diagram showing details of an imaging optical system portion 30. FIG.
As shown in (1), the semiconductor laser portion 31 includes the semiconductor laser 10 and a semiconductor laser cooling device (heat sink).
70.

The image forming optical system portion 30 has a collimator lens 50, an objective lens 52, and a cover glass 53.

One end of an optical fiber 72 is connected to the semiconductor laser 10 via an optical fiber connector 71-1. The other end of the optical fiber 72 is the optical fiber connector 7
The end of the optical fiber 72 is connected to the imaging optical system portion 30 via 1-2 so that the end portion of the optical fiber 72 is optically aligned with the collimator lens 50.

The laser beam emitted from the semiconductor laser enters the optical fiber 72 from the optical fiber connector 71-1, is guided by the optical fiber 72, exits from the optical fiber connector 71-2, and enters the imaging optical section. To do. At this time, what is attached to the moving stage 28 of the laser plate making apparatus of FIG. 1 is the imaging optical system part 3 shown in FIG.
Only 0, which is smaller and lighter than the conventional plate making apparatus (FIG. 6).

As for the beam profile of the laser beam, the pattern of the laser beam emitted from the optical fiber 72 (for example, 20 W for the model SLD324 of 2 W) is used.
The 0 μm × 1 μm P-polarized stripe) is mode-converted while being guided by the optical fiber 72. That is, since the pattern of the laser beam does not depend on the characteristics of the emitted laser beam of the semiconductor laser and is determined by the core diameter and NA of the optical fiber 72, the range of selection of the semiconductor laser used in this laser plate making apparatus becomes wide, As a laser plate making apparatus, there is an advantage that the possibility of performance improvement is high.

FIG. 2B shows the details of the optical system after the optical fiber 72. The laser beam emitted from the optical fiber 72 is collimated into parallel light by the collimator lens 50, focused by the objective lens 52, and focused on the resin sheet 2 through the cover glass 53. In this prototype, the following optical elements were used.

Optical fiber 72 ... Sony Corporation model number SLU304XR, GI (great index) type fiber, core diameter 400 μm, NA = 0.2, L (length) = 2 m Collimator lens 50 ... EFL (effective focal length effective focal length) length) = 24 mm, NA = 0.2 Objective lens 52 ... EFL = 24 mm, NA = 0.2

At this time, the spot diameter d is the optical fiber 72.
Depends on the core diameter. Spot diameter d = fiber core diameter × (objective lens EFL / collimator EFL) = 400 μm × (3 mm / 24 mm) = 50 μm

The spot diameter d is 50 μm, which is approximately equal to the focal stripe width 66.7 μm in the conventional laser plate making apparatus.

As described above, since it does not depend on the characteristics of the radiation beam of the semiconductor laser, for example, as a semiconductor laser,
Near infrared laser diode manufactured by Sony Corporation Model number SLD4
02 laser diode with an output of 15 [W], SDL, Inc. of California, USA. Model number DL3450
-S output linear array laser diode with 15 [W] output, company's model number DL3460-S output 20 [W] linear array laser diode, or semiconductor laser of the type in which a plurality of laser diodes are connected by a branch fiber It becomes possible to adopt. The same optical fiber 72 can be used for both semiconductor lasers without changing the imaging optical system part 30.

[Multi-Beam Laser Plate Making Apparatus] FIG. 3
Is an embodiment in which the present invention is applied to a multi-beam type laser plate making apparatus. The mover 27 is screwed onto the ball screw 26, and the mover 26 moves linearly by the rotation of the ball screw 26. Ten moving stages 28-1 to 28-10 are integrally connected to the mover 26. Imaging optical system portions 30-1 to 30-10 are mounted on the moving stages 28-1 to 28-10, respectively. One ends of the optical fibers 72-1 to 72-10 are connected to the imaging optical system portions 30-1 to 30-10 via optical fiber connectors, respectively. The other ends of the optical fibers 72-1 to 72-10 are connected to the semiconductor laser via an optical fiber connector, respectively.
Semiconductor laser cooling devices 70-1 to 70-10 for cooling the semiconductor laser are attached to the semiconductor laser, respectively. The semiconductor laser cooling devices 70-1 to 70-10 may be fixed to any position of the laser plate making device. The multi-beam type embodiment shown in FIG. 3 has all the effects described in connection with the single-beam type laser plate making apparatus shown in FIG. 1, and additionally has the effect that the plate making time is shortened.

[Effects of Embodiment] According to the laser plate making apparatus of this embodiment, of the semiconductor laser and the optical system, only the laser block 21 having the imaging optical system needs to be mounted on the laser moving stage 28. Therefore, the size and weight of the moving part can be reduced. The reduced weight of the moving parts substantially eliminates inertial problems during transfer.

The semiconductor laser can be arranged at a position different from the moving part, so that there is no restriction on the size of the semiconductor laser cooling device and a device having a large cooling capacity can be used. If the cooling capacity is increased, a semiconductor laser having a higher output can be used as a reflective effect, and the plate making speed can be further increased.

Since the semiconductor laser and the imaging optical system are connected by the optical fiber, the focal spot diameter does not depend on the characteristics of the semiconductor laser, but is determined by the core diameter of the optical fiber and the imaging optical system. The semiconductor laser of can be used.

Further, since the size of the moving portion is reduced, the degree of freedom in designing the periphery of the plate cylinder is increased, and it is possible to adopt a multi-beam system having a larger number of beams than the conventional one.

By interposing the optical fiber 28 between the semiconductor laser 10 and the imaging optical system, the semiconductor laser 1
There is an advantage that various high-power semiconductor lasers currently on the market can be adopted regardless of the emission pattern of 0.

If desired, by branching the optical fiber 28 connecting the semiconductor laser 10 and the imaging optical system, a monitor or the like may be connected to the tip of the branched optical fiber, so that the resin for platemaking can be obtained. It is possible to proceed with the plate making process while checking the concave portions of the sheet making sheet.

[0075]

According to the present invention, there is an advantage that the size and weight of the laser block can be reduced in the laser plate making apparatus.

Further, according to the present invention, it is possible to provide a laser plate making apparatus to which a semiconductor laser cooling device having a high cooling capacity can be easily attached as the output power of the semiconductor laser increases.

Further, according to the present invention, it is possible to provide a laser plate making apparatus in which the number of beams is increased when the multi-beam method is adopted.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main part of an embodiment of a laser plate making apparatus according to the present invention.

FIG. 2A is a diagram showing an example of a laser block of the laser plate making apparatus of FIG. FIG. 2B is a diagram showing details of the imaging optical system portion of FIG.

FIG. 3 is a diagram showing a main part of an embodiment of a multi-beam type laser plate making apparatus according to the present invention.

FIG. 4 is a diagram showing the overall configuration of a laser plate making apparatus.

5 is a diagram showing main blocks of the laser plate making apparatus of FIG.

FIG. 6 is a diagram showing a main part of a conventional laser plate making apparatus using a semiconductor laser having a single beam method and a light output of 2 watts.

7 is a diagram showing a cross-sectional structure of the laser block of FIG.

FIG. 8 is a diagram showing a conventional multi-beam type laser plate making apparatus.

[Explanation of symbols]

 1 plate body 2 resin sheet 4 axis 7 plate cylinder rotation drive motor 10 semiconductor laser 21 laser optical system 22 rails 23R, 23L bearing part 24 laser block moving motor 26 ball screw 27 mover 28 moving stage 30 imaging optical system Part 31 Semiconductor laser part 32 Microcomputer (CPU) 35 Driver for plate cylinder rotation (drive device for plate cylinder rotation) 38 RAM 42 Gamma table 50 Collimator lens 51 Anamorphic prism 52 Objective lens 53 Cover glass (CG) 70 Semiconductor laser Cooling device (heat sink) 71, 71-1, 71-2 Optical fiber connector 72 Optical fiber

Claims (5)

[Claims] 1. In a laser plate making apparatus, a fixed semiconductor laser portion having at least a semiconductor laser, an imaging optical system portion that moves corresponding to a laser beam irradiation position, the semiconductor laser portion and the imaging optical system. A laser plate making apparatus, comprising: an optical fiber for connecting a portion to the plate. 2. The laser plate making apparatus according to claim 1, wherein the imaging optical system portion has at least a collimator lens and an objective lens. 3. The laser plate making apparatus according to claim 1, wherein a semiconductor laser cooling device is attached to the semiconductor laser. 4. A laser plate making apparatus, comprising: a plurality of fixed semiconductor laser portions each having at least a semiconductor laser; and a plurality of semiconductor laser portions provided corresponding to each of the plurality of semiconductor laser portions. A plurality of image-forming optical system parts that move correspondingly; and a plurality of optical fibers that respectively couple each of the semiconductor laser parts and the corresponding image-forming optical system parts. Laser plate making equipment. 5. The laser plate making apparatus according to claim 4, wherein a semiconductor laser cooling device is attached to each of the semiconductor lasers.