JPH07333859A - Exposure device - Google Patents

Abstract

PURPOSE:To provide an exposure device making a plate by the simultaneous exposure of two sides, in which the printing start position of two sides, a size reduction factor and a position for electrification operation are easily adjusted. CONSTITUTION:In this exposure device, simultaneous two-side exposure in terms of data from 1st and 2nd video data generation circuits 401 and 402 is performed to a carried printing plate with laser beams from 1st and 2nd laser beam emission circuits 331 and 332 by a polygon mirror 32. The moving amount of the printing plate in a subscanning direction is adjusted according to a counted value from a pulse counter 44 designated from an operator panel 45 and counted values from 1st and 2nd line number counters 371 and 372 based on detection signals from 1st and 2nd BDE sensors 351 and 352. Then, the printing start position of the specified line of the printing plate is adjusted according to counted values from 1st and 2nd clock number counting counters 361 and 362 based on detection signals from 1st and 2nd BDS sensors 341 and 342.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for plate making by simultaneous two-sided exposure.

In recent years, CTS (Compu
terized Typesetting System
(m: Electronic editing typesetting system) has made remarkable progress, and the platemaking process has been rationalized. Therefore, OPC (O
An organic photoconductor (RPG) has been developed to allow direct writing from a semiconductor laser, and the plate making process has been shortened. Further, simultaneous shortening of the plate making process has led to simultaneous double-sided exposure, which requires various adjustments and simplification of adjustments is desired.

[0003]

2. Description of the Related Art FIG. 11 shows a side view of a conventional plate making apparatus. An exposure apparatus as an object of the present invention is used in the plate making apparatus 11 shown in FIG.

Referring to FIG. 11, the plate making apparatus 11 includes a plate feeding section 1
2, exposure unit 13, developing unit 14, drying unit 15, edge cleaning unit 16, fixing unit 17, cooling unit 18, elution unit 1
9, a gum section 20, and a drying section 21.

The plate supply section 12 is provided with a hopper 23 for storing about 500 plate materials (OPC plate materials) 22. Exposure unit 13
Includes an optical unit 24 and chargers 25a and 25b,
The plate materials 22 sent one by one from the plate supply section 12 are fixed on a table 26 and exposed with a semiconductor laser beam or a gas laser beam to form a latent image.

The developing section 14 develops the plate material 22 exposed by the exposing section 13 with liquid toner. The drying unit 15 dries the plate material 22 developed by the developing unit 14. The edge cleaning unit 16 removes the toner attached to the edge of the plate material 22. The fixing unit 17 heats and fixes the toner image on the plate material 22 that has been edge-cleaned.

The cooling unit 18 cools the fixed plate material 22 with a fan or the like. The elution section 19 showers the cooled plate material 22 with a strong alkali and a weak alkali to dissolve and wash away the photosensitive layer in the non-image area. The gum portion 20 is subjected to a desensitizing treatment of the plate material 22 which has melted the photosensitive layer in the non-image portion and has flowed out to homogenize it. The drying unit 21 is for drying and cooling the gummed plate material 22.

FIG. 12 shows a plan view of a conventional exposure section. The exposure unit 13 is configured so that the same plate material 22 can be exposed on two surfaces at the same time in order to improve the plate making efficiency, and the laser light L ₁ emitted from the two light sources 27a and 27b. L ₂ is reflected in different directions (opposite directions) by different surfaces of the polygon mirror 28 rotated by the spindle motor, and the same plate material 22 is moved up and down in the feeding direction via individual lenses 29a and 29b and mirrors 30a and 30b. Two-sided exposure is performed at two positions.

The sub-scanning direction of the plate material 22 (feed direction)
The write start position of is set by the time from the recording start signal or the number of lines.

[0010]

However, in the two-sided simultaneous exposure by the exposure unit 13, the scanning direction is reversed with respect to the plate material 22 and it is difficult to match the writing positions in the main scanning direction. At the same time, the writing position in the sub-scanning direction
Since it is determined by the time from the recording start signal and the number of lines, there is a problem that the amount of blank space between the two surfaces is displaced.

Further, the printing width is deviated due to the difference (variation) between the lenses 29a and 29b for the two surfaces, and the vertical line is deviated due to a subtle difference (assembly error) in the incident angle to the polygon mirror 28. There is a problem.

Further, since the charging is performed by the two chargers 25a and 25b, the charging amount is increased in the overlapping portion (see FIG. 10).
(Refer to the broken line in (B)), but there is a problem that the print quality deteriorates.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide an exposure apparatus that facilitates adjustment of the printing start position, reduction ratio, and charging operation position of two surfaces.

[0014]

In order to solve the above-mentioned problems, according to a first aspect of the present invention, irradiation light emitted from two light sources is reflected in different directions by a rotated polyhedral mirror, and is conveyed to a printing plate material. An exposure apparatus for performing simultaneous two-sided exposure of predetermined data, which detects conveyance of the plate material, and transport counting means for determining a printing line of the plate material with a set specified value, and the transport counting means. First and second line detecting means for detecting the line printed on each surface of the plate material after the printing line is determined by the means, and the detection from the first and second line detecting means Count each signal,
First and second line counting means for setting the print line when the value is a predetermined value, and specified values of the transport counting means are set, and the predetermined values of the first and second line counting means are respectively set. And an input means for setting the two surfaces separately.

According to a second aspect of the present invention, there are provided first and second print detecting means for receiving the irradiation light from the polyhedral mirror which is applied to each surface of the plate material to obtain a signal for starting printing in the printing line direction. First and second timer means for starting the exposure after a lapse of a predetermined time from the signals from the first and second print detecting means, and the first and second timer means by the input means. The exposure start time of the timer means is set separately for the two sides of the plate material.

According to a third aspect of the present invention, in the exposure device, the irradiation light emitted from the two light sources is reflected by the rotated polygon mirror in different directions to perform simultaneous two-sided exposure of predetermined data on the conveyed plate material. Input means for setting a reduction rate value for the predetermined data for performing, and changing each reduction rate of the predetermined data on each surface according to the reduction rate value from the input means to the two light sources. First and second giving exposure instructions
And a data generating means of.

According to a fourth aspect of the present invention, the first and second data generating means store the incoming predetermined data, and a reduction ratio value set by the input means as an address of the predetermined data. A storage means for storing the data corresponding to the storage means, an addition / subtraction means for adding predetermined data of the storage means and a reduction rate value of the storage means, and a data generation means for generating data according to the reduction rate value, It is configured to include.

According to a fifth aspect of the present invention, in the exposure apparatus, the irradiation light emitted from the two light sources is reflected in different directions by the rotating polygon mirror to perform simultaneous two-side exposure of the conveyed plate material with predetermined data. Transport counting means for detecting the transport of the plate material,
Charging means provided corresponding to the respective surfaces for charging the respective surface of the plate material with the respective count values individually set according to the count of the transport counting means, and the respective count values separately for the respective surfaces. And an input means for setting.

According to a sixth aspect of the present invention, the charging means comprises a charging device for charging the plate material, a charge-on setting section for setting a count value of the charging start by the charging device, and a charging stop by the charging device. A charge-off setting unit for setting the count value,
Power supply means for applying a voltage to the charger by the counting by the transport counting means and the count values of the charge-on setting section and the charge-off setting section.

[0020]

As described above, according to the first aspect of the invention, when performing simultaneous two-sided exposure of the conveyed plate material, the detection signals of the first and second line detecting means are counted by the first and second line counting means. It is counted as a print line when it reaches a predetermined value determined by the input means for each surface individually. As a result, the print start line on each surface can be adjusted, and the amount of blank space between each surface can be easily set.

According to the second aspect of the present invention, the printing lines for simultaneous two-sided exposure of the plate material are defined, and the first and second sides are set individually by the inputting means from the detection of the first and second printing detecting means. Printing is started in the print line direction after a predetermined time by the second timer means. This makes it possible to easily adjust the print start position on each surface opposite to the scanning direction.

According to the third and fourth aspects of the present invention, the reduction ratio value of the predetermined data for printing on each side is set in the storage means of the first and second data generation means from the input means, and the reduction ratio value is set. And the predetermined data are used to generate data according to the value of the reduction ratio to perform exposure. This makes it possible to easily adjust the print width and vertical line shift.

According to the fifth and sixth aspects of the invention, each surface of the plate material is charged by counting the transport state of the plate material and the charge-on and charge-off count values that are set individually for each surface.
As a result, the charge amount can be easily adjusted, and the print quality can be improved.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a block diagram of an embodiment of the present invention.
The exposure apparatus 31 shown in FIG. 1 is used for the plate making apparatus shown in FIG. 11, and performs two-side simultaneous exposure.
A polygon mirror 32 rotated by a spindle motor is provided with two light sources, a first and a second laser emission circuit 3.
The laser light emitted from 3 ₁ , 33 ₂ is reflected, and the first and second BDS serving as the first and second print detection means are reflected.
(Printing start position) Sensors 34 ₁ and 34 ₂ and first and second
Are detected by the first and second BDE (printing end position) sensors 35 ₁ and 35 ₂ which are line detection means. In addition,
The exposure mechanism for the plate material will be described later.

The first and second BDS sensors 34 ₁ , 34
The output of ₂ is input to the first and second clock counters 36 ₁ and 36 ₂ which are first and second timer means, and the outputs of the first and second BDE sensors 35 ₁ and 35 ₂ are It is input to the first and second line number counters 37 ₁ and 37 ₂ which are first and second line counting means. In addition,
First and second clock counters 36 ₁ , 36 ₂
A clock having a predetermined frequency is input to the oscillator.

First and second clock counters 3
The count UP values of 6 ₁ and 36 ₂ are first and second video data generating means, which are first and second data generating means, as print start signals via F / F (flip-flop) circuits 39 ₁ and 39 _2. It is input to the circuits 40 ₁ and 40 ₂ . In addition, the first and second line number counters 37 ₁ and 3
The count UP value of 7 ₂ is input to the first and second video data generating circuits 40 ₁ and 40 ₂ as a print enable signal via the F / F circuits 39 ₃ and 39 ₄ .

Then, the video data is sent to the first and second video data generation circuits 40 ₁ and 40 ₂ from the host device, and the video data is sent to the first and second laser emission circuits 33 ₁ and 33 ₂ . The first and second laser emission circuits 33 ₁ and 33 ₂ irradiate the polygon mirror 28 with laser light in accordance with the video data.

On the other hand, CPU (central processing unit) 4
1 is the first and second clock number counters 36 ₁ ,
36 ₂ and the first and second line number counters 37 ₁ , 3
7 ₂ and the first and second video data generation circuits 40 ₁ ,
40 ₂ and drive control. The CPU 41 also controls a servo drive circuit 42 that drives a servo motor that conveys the plate material (in the sub-scanning direction).

The servo motor is provided with an encoder 43 which is a transport counting means, and the pulse from the encoder 43 is output to the pulse counter 44. Also, CP
U41 specifies the specified value on the pulse counter 44,
A print origin signal is sent from the pulse counter 44 to the CPU 41. An operator panel 45 for inputting by an operator is connected to the CPU 41.

Next, FIG. 2 shows a plan configuration diagram of FIG.
In FIG. 2, a polygon mirror 32 is attached to the spindle of a spindle motor (not shown) and rotates in the arrow direction.

On the other hand, the laser light emitted from the first semiconductor laser 33 ₁ which is the first laser emission circuit passes through the collimator lens 51 ₁ and the cylinder lens 52 ₁ and is reflected by the mirrors 53 ₁ and 53 _2. The reflected laser light is scanned by the rotating polygon mirror 32, passes through the lower fθ lens 54 ₁ in the drawing, is reflected by the first mirror 55 ₁ , and is reflected by the second mirror 56 ₁ and the cylinder mirror 57 ₁ . A of the plate material (OPC plate material) conveyed to the upper and lower sides of the drawing via
The surface is illuminated. The first BDS sensor 34 ₁ and the first BDE sensor 35 are provided on both ends of the first mirror 55 _1.
1 is placed.

The collimator lens 52 ₁ (52 ₂ )
Is to increase the parallelism (straightness) of the laser light, which has a directivity and is emitted radially from one point but travels radially. In addition, the fθ lens 54 ₁ (54 ₂ )
The laser light scanned by the polygon mirror 32 is reflected by the first mirror 55 ₁ (55 ₂ ), but the distortion of the image at the mirror end caused by the polygon mirror 32 rotating at a constant angular velocity is corrected. It is for you. Further, the cylinder mirror 57 ₁ (57 ₂ ) is for correcting the image distortion due to the surface tilt (parallelism between the reflecting surface and the rotation axis) of the polycon mirror 32.

Similarly, the second laser emission circuit, the second laser
The laser light emitted from the semiconductor laser 33 ₂ passes through the collimator lens 51 ₂ and the cylinder lens 52 ₂ and is reflected by the mirrors 53 ₃ and 53 ₄ to be scanned by the rotating polygon mirror 32. It passes through the fθ lens 54 ₂ downward in the drawing, is reflected by the second mirror 55 ₂ , and is reflected by the second mirror 56 ₂ and the cylinder mirror 57 _2.
The surface B of the plate material (OPC plate material) conveyed to the back surface of the drawing through the is irradiated. Further, the second BDS sensor 34 ₂ and the second BDE sensor 3 are provided on both ends of the first mirror 55 _2.
5 ₂ is arranged (first BDS sensor 34 ₁ and first BDE
The left and right sides of the sensor 35 ₁ are reversed. In this way, the plate material is simultaneously exposed on two sides.

Here, FIG. 3 shows an explanatory view of the exposure state of the plate material. FIG. 3 shows a plate material (OPC plate material) 58 which is exposed by the exposure apparatus 31 of the present invention.
In comparison with No. 8, two-sided simultaneous exposure of the A side and the B side is performed. In FIG. 3, the plate material 58 is fed in the sub-scanning direction by the servo motor, and T (the number of pulses from the encoder 43) is started from the feeding start (charging start for exposure).
It will be located on the first writing line on side A later. At this time, the first writing line on the B side is after D (the delay time and the number of pulses from the encoder 43).

The number of printing lines on the A side and B side is the first.
While being detected by the second BDE sensors 35 ₁ and 35 ₂ , when the printing of the predetermined line is completed, the upper margin t ₁ , the distance t ₂ between the A side and the B side, and the lower margin t ₃ are obtained.

On the other hand, in the main scanning of the A surface and B surface, the scanning directions are reversed due to the characteristics of the above mechanism, and the first and second BDs are
After the predetermined number of clocks is counted (N ₁ , N ₂ ) from the detection of the S sensors 34 ₁ and 34 ₂ , the printing of the line is started. At this time, a ₁ and b ₁ are left margins, a ₂ and b ₂ are print widths of the A and B sides, and a ₃ and b ₃ are right margins.

Therefore, FIG. 4 shows a timing chart in the sub-scanning direction of FIG. First, when the servo motor is rotated via the servo motor drive circuit 42 in response to a servo motor start instruction from the CPU 41 to start conveying the plate material 58 in the sub-scanning direction (FIG. 4C), the encoder 43 rotates the servo motor. Pulse is generated according to
(A)), this pulse is counted by the pulse counter 44 (FIG. 4 (B)).

The pulse counter 44 sends a print origin signal to the CPU 41, and the CPU 41 designates a specified value (N
Individual) to the pulse counter 44. In this case, the polygon mirror 32 scans the laser light (laser light that is not video data) from the first and second laser emission circuits 33 ₁ and 33 ₂ .

The above laser light is detected by the first and second BDE sensors 35 ₁ and 35 ₂ (FIG. 4 (D)), which is after the start of rotation of the servo motor and after counting N by the pulse counter, After the detection of the first BDE sensor 35 ₁ , the print start flag is set (FIG. 4 (E)).

After that, when the detection pulse of the first BDE sensor 35 ₁ is counted by the first line number counter 37 ₁ by a predetermined number (M), the F / F circuit 39 ₃ is started and the A-side print enable is the first. Video data generation circuit 40 ₁
To the first laser emission circuit 33 ₁ (FIG. 4 (H)) every time the first BDS sensor 34 ₁ is detected (line by line) (FIG. 4 (H)).
(I)).

On the other hand, each time the second BDE sensor 35 ₂ detects from the print start flag, the second line number counter 37 ₂
Counts (Fig. 4 (J), (K)), and a predetermined number (O)
When counted, the B-side print enable is sent to the _second video data generating circuit 40 ₂ via the F / F circuit 39 ₄ (FIG. 4 (K)).

That is, the printing of the B side is started after a predetermined amount of delay (delay raster amount D) from the printing start of the A side. In this case, the delay raster amount is appropriately set by the operator from the operator panel 45. As a result, it is possible to secure the space between the A surface and the B surface, and to set the amount freely.

Next, FIG. 5 shows a tie in the main scanning direction of FIG.
A minging chart is shown. First, the first and second clocks
Number counting counter 36₁, 36₂From the oscillator circuit 38
Lock CLK (Fig. 5 (A)) is input,
The preset value (N₁, N₂)
F / F circuit 39 when counting the clocks₁, 39 ₂
Print start signal via the first and second video
It is sent to the data generation circuit 38. And video data generation
The circuit 38 is sent from the host device at the start of printing.
The laser light control signal according to the video data
2 laser emission circuit 33₁, 33₂To send to.

Therefore, the first and second BDS sensors 34
_From the time when ₁ , 34 ₂ receives the laser light (see FIG.
(B) and (F), the first and second clock number counters 36 ₁ and 36 ₂ start counting (FIG. 5 (C),
(G)). A print start signal when the first clock counter 36 ₁ counts N clocks is sent to the _first video data generation circuit 40 ₁ and the first laser emission circuit 33 ₁ according to the video data. Then, printing of side A is performed (FIGS. 5D and 5E). This is repeated for each line feed (one line).

At the same time, a print start signal when the second clock number counter 36 ₂ counts the M clock numbers is sent to the _second video data generation circuit 40 ₂ and the print start signal is sent in response to the video data. 2 laser emission circuit 3
3 ₂ Printing B side is performed by repeated for each new line (Fig. 5 (H), (I) ). According to this, it is possible to separately adjust the print start positions of the A surface and the B surface in the main scanning direction with values set in advance by the first and second BDS sensors 34 ₁ and 34 ₂ when light is received. The margin amount can be set arbitrarily and accurately.

In this way, it is possible to avoid the vertical line inconsistency caused by the deviation of the recording start positions of the A surface and the B surface due to the error such as the surface tilt of the polygon mirror 32 and the uneven rotation of the spindle motor. It is possible to perform color printing using the manufactured plate without causing color misregistration.

Next, FIG. 6 shows a block diagram of print width adjustment. FIG. 6 shows a block diagram for adjusting the printing width of only one surface in the simultaneous two-sided exposure of the plate material, but the other surface is similarly configured.

In FIG. 6, the first video data generation circuit 40 ₁ has a correction data register 61 connected to the CPU 41, and the correction data for compression and expansion is stored in the operator panel 45.
The data in the reduction ratio memory 62 in which the data for compression / decompression is stored is corrected.

The reduction ratio memory 62 is preset by the signal from the _first clock number counter 36 ₁ , and the address counter 63 outputs the reduction ratio data of the address.

On the other hand, the dot period register 64 which is the storing means stores the reference dot period data, and the output of the dot period register 64 and the output of the reduction ratio memory 62 which is the storing means are addition and subtraction means which are addition and subtraction means. In addition, the input video data is compressed and expanded by the data generation circuit 67 to the first laser emission circuit 33 ₁ based on the dot cycle counter 66 which constitutes the data generation means and is sent out. That is, the compression / decompression of video data can be freely set from the operator panel 45.

Here, FIG. 7 shows an explanatory view of the print width adjustment. In FIG. 7, compressed bit information “1” or “0” from the reduction ratio memory 62 is added to each dot data from the dot cycle register 64 by the adder / subtractor 65. For example, if 1 dot is 36 clocks (1 clock is 3.3 ns) for printing at 454 dpi and the value read from the reduction ratio memory 62 is "1", 1 dot is configured with 35 clocks and "0" is set. In the case of, 1 dot is constructed with 36 clocks.

In this case, 0.0015 when the print width when dot data is output as it is is 100%.
The reduction ratio is adjusted to 95% to 100% in mm.

That is, the first and second video data generating circuits 40 ₁ and 40 ₂ in FIG. ₁ are configured as shown in FIG.
The time for one dot is changed by the value read from No. 2, so that each printing width a of the A side and B side in FIG.
₁ and b ₂ can be adjusted separately, and a lens system (collimator lens, cylinder lens, fθ) configured for each surface
Deviation due to variations in lens) and the polygon mirror 32
It is possible to easily adjust the vertical line shift due to a slight shift in the incident angle of the laser beam to the.

Next, FIG. 8 shows a block diagram of charge amount adjustment. FIG. 8 shows a block diagram of the charge amount adjustment of only one surface in the simultaneous two-sided exposure of the plate material, but the other surface is similarly configured.

In FIG. 8, the plate material 58 is the exposure table 7.
1, the exposure table 71 is rotationally driven by a servo motor 72 controlled by the servo drive circuit 42 of FIG. The pulse from the encoder 43 that generates a pulse by the rotation of the servo motor 72 is sent to the pulse counter 44, and its output is sent to the CUP 41 and the charging unit 73 which is a charging unit.

The charging unit 73 charges the plate material 58 with a predetermined polarity before exposure, and the charge-on set value of the charge-on setting unit 74 and the count value from the pulse counter 44 are stored in the first adder / subtractor 75. In addition to addition and subtraction, the charge-off design value of the charge-off setting unit 76 and the count value from the pulse counter 44 are added and subtracted by the second adder-subtractor 77. The charge-on setting section 74 and the charge-off setting section 76 are arbitrarily set by the operator panel 45.

The outputs of the first and second adder / subtractors 75 and 77 are supplied with the first charge signal as the charge-on timing and the charge-off timing in the high-voltage power supply unit 78, which is the power supply means, and the first charger 79. ₁ (B
The surface applies the first applied voltage (the second applied voltage for surface B) to the second charger 79 ₂ ) according to each timing.

That is, the charging timing of the A surface and the B surface of the plate material 58 is adjusted individually by the panel 45, which has been prepared.

Therefore, FIG. 9 shows a timing chart of the charge amount adjustment, and FIG. 10 shows an explanatory view of the charged state of the plate material.

First, N ₂ (N _{1 for the} B side) is set in the charge-on setting section 74 as the charge-on set value for the A side, and N ₃ is set in the charge-off setting section 76 as the charge-off set value for the A side. (B side is N ₄ ) is set.

In FIG. 9, the pulse from the encoder 43 is
Is counted by the pulse counter 44 (FIG. 9 (A),
(B)), count N₁Of the second charge signal
The rising is from the first adder / subtractor 75 to the high-voltage power supply unit 78.
To the second charger 79 ₂Mark the second applied voltage on
(FIG. 9 (E), (F), FIG. 10 (A)). Also,
Count N₂The rising edge of the first charge signal is
It is sent from the adder / subtractor 75 of 1 to the high-voltage power supply unit 78.
The first charger 79₁The first applied voltage is applied to the
9 (C), (D), FIG. 10 (A)).

On the other hand, at count N ₃ , the falling edge of the first charge signal is sent from the second adder / subtractor 77 to the high voltage source unit 78 to stop the voltage application to the _first charger 79 ₁ (FIG. 9 (C), (D), FIG. 10 (A)). At the count N ₄ , the falling edge of the second charge signal is sent from the second adder / subtractor 77 to the high-voltage power supply unit 78 to stop the voltage application to the _second charger 79 ₂ (FIG. 9 (E)). , (F), FIG. 19 (A)).

By adjusting the timings of the voltages applied to the first and second chargers 79 ₁ and 79 ₂ in this way, as shown in FIG. Can be easily adjusted to be uniform, whereby the exposure state can be made uniform and the printing quality can be improved.

[0064]

As described above, according to the first aspect of the present invention, when performing simultaneous two-sided exposure of the conveyed plate material, the detection signals of the first and second line detection means are changed to the first and second detection signals. By counting by the second line counting means, and when it reaches the predetermined value which is individually determined for each surface by the input means, it is set as a printing line,
The print start line on each surface is adjustable, and the amount of blank space between each surface can be easily set.

According to the second aspect of the present invention, the printing line for simultaneous two-sided exposure of the plate material is defined, and the first line is set by the input unit separately from the detection of the first and second print detection units. By starting printing in the print line direction after a predetermined time by the second timer means, it is possible to easily adjust the print start position on each surface opposite to the scanning direction.

According to the third and fourth aspects of the present invention, the reduction ratio value of the predetermined data for printing separately for each surface is set from the input means to the storage means of the first and second data generating means, and the reduction ratio is set. By generating data corresponding to the value of the reduction ratio by the value of and the predetermined data and performing the exposure, it is possible to easily adjust the print width and the vertical line shift.

According to the fifth and sixth aspects of the present invention, by charging each surface of the plate material with the count of the transport state of the plate material and the charge-on and charge-off count values set individually for each surface, The charge amount can be easily adjusted, and the print quality can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a plan configuration diagram of FIG.

FIG. 3 is an explanatory diagram of an exposed state of a plate material.

FIG. 4 is a timing chart in the sub-scanning direction of FIG.

5 is a timing chart in the main scanning direction of FIG.

FIG. 6 is a block diagram of print width adjustment.

FIG. 7 is an explanatory diagram of print width adjustment.

FIG. 8 is a block diagram of charge amount adjustment.

FIG. 9 is a timing chart of charge amount adjustment.

FIG. 10 is an explanatory diagram of a charged state of the plate material.

FIG. 11 is a side view of a conventional plate making apparatus.

FIG. 12 is a plan view of a conventional exposure unit.

[Explanation of symbols]

31 exposure device 32 polygon mirror 33 ₁ first laser emission circuit 33 ₂ second laser emission circuit 34 ₁ first BDS sensor 34 ₂ second BDS sensor 35 ₁ first BDE sensor 35 ₂ second BDE sensor 36 ₁ 1st clock number counter 36 ₂ 2nd clock number counter 37 ₁ 1st line number counter 37 ₂ 2nd line number counter 38 Oscillation circuit 40 ₁ 1st video data generation circuit 40 ₂ 2nd Video data generation circuit 41 CPU 42 Servo drive circuit 43 Encoder 44 Pulse counter 45 Operator panel 58 Plate material 62 Reduction ratio memory 64 Dot cycle register 65 Adder / subtractor 66 Dot cycle counter 67 Data generation circuit 73 Charging section 74 Charge-on setting section 76 charge-off setting unit 78 high voltage power supply unit 79 ₁ first band Vessel 79 ₂ second charger

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03G 15/04 111 21/14

Claims (6)

[Claims] 1. Irradiation light emitted from two light sources (33 ₁ , 33 ₂ ) is reflected in different directions by a rotating polygon mirror (32), and predetermined data is simultaneously recorded on a conveyed plate material (58). An exposure device for performing two-sided exposure, which detects the conveyance of the plate material (58), and conveys counting means (43, 43) for determining a printing line of the plate material (58) with a set specified value. 44) and first and second line detecting means for detecting the line printed on each surface of the plate material (58) after the printing line by the transport counting means (43, 44) is determined. (35 ₁ , 35 ₂ ) and the detection signals from the first and second line detection means (35 ₁ , 35 ₂ ), respectively, and the first and a second line counter means (37 _1, 37 _2), said conveyor Sets the specified value of the number of means (43, 44), said first and second line counting means (37 _1, 37
_2. An exposure apparatus comprising: an input means (45) for setting the predetermined value of ₂ ) separately on each of two surfaces. 2. First and second print detections for receiving a light emitted from the polygon mirror (32), which is applied to each surface of the plate material (58), to obtain a signal to start printing in a print line direction. Means (34 ₁ , 34 ₂ ) and first and second timers for starting the exposure after a predetermined time period by obtaining signals from the first and second print detecting means (34 ₁ , 34 ₂ ). Means (36 ₁ , 36 ₂ ), and the exposure start time of the first and second timer means (36 ₁ , 36 ₂ ) is separately supplied to the two surfaces of the plate material by the input means (45). The exposure apparatus according to claim 1, wherein the exposure apparatus is set respectively. 3. Irradiation light emitted from two light sources (33 ₁ , 33 ₂ ) is reflected in different directions by a rotated polygon mirror (32), and predetermined data is simultaneously recorded on a conveyed plate material (58). In an exposure apparatus for performing two-sided exposure, input means (45) for setting a reduction rate value for the predetermined data to be printed, and each side according to the reduction rate value from the input means (45) First and second data generating means (40 ₁ , 40 ₂ ) for changing the reduction ratio of each of the predetermined data and giving an exposure instruction to the two light sources (33 ₁ , 33 ₂ ). Characteristic exposure equipment. 4. The first and second data generating means (4)
0 ₁ , 40 ₂ ) stores the incoming predetermined data and the storage means (64) and the reduction ratio value set by the input means (45) in association with the address of the predetermined data. Storage means (62)
And predetermined data of the storage means (64) and the storage means (62)
4. An addition / subtraction means (65) for adding the reduction rate value of and a data generation means (66, 67) for generating data according to the reduction rate value. Exposure equipment. 5. Irradiation light emitted from two light sources (33 ₁ , 33 ₂ ) is reflected in different directions by a rotating polygon mirror (32), and predetermined data is simultaneously recorded on a conveyed plate material (58). In an exposure apparatus that performs two-sided exposure, a transport counter (4) that detects the transport of the plate material (58).
3, 44) and the respective surfaces of the plate material (58) which are separately charged in accordance with the counts of the transport / counter means (43, 44). And an inputting means (45) for setting the count value separately for each surface. 6. The charging means (73) is a charger (79 ₁ , 7) for charging the plate material (58).
9 and _2), the band Electric (79 _1, 79 ₂₎ charge - on setting section counts the start charge is set by the (74), the band Electric (79 _1, 79 ₂₎ by the charging stopping count , A charge-off setting section (76), the counting by the transport counting means (43, 44), the charge-on setting section (74) and the charge-off setting section (76)
Count and the belt-Electric (79 _1, 79 ₂₎ and the power supply means (78) for applying a voltage to the exposure apparatus according to claim 5, characterized in that it comprises a.