JPH045370B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a plate-making machine for making an original plate for offset printing, and is a plate-making machine suitable for use when sometimes printing two sides of the same original on a master paper (original plate). The present invention relates to an exposure control device.

[Prior art]

Conventionally, when printing multiple copies of the same original on a master paper, the first time the image is taken, black paper 001 is placed in the area where the original is placed and exposed, as shown in Figure 1a, and the second time the image is taken, the black paper 001 is exposed. As shown in b, the black paper 1 is placed on the original portion of the first exposure so that the latent image 002 formed by the first exposure is not exposed to light. In the figure, 003 is a manuscript table, 004 is a manuscript, 005 and 006 are lenses and mirrors that constitute the optical system, 007 is a printing plate, and 0
08 is an exposed area, 009 is an unexposed area, and 010 is a latent image formed by the second exposure.

However, in such a light shielding method using black paper, it is necessary to move the document 004 during the first and second imaging, which makes the work cumbersome and lowers the positioning accuracy. has the disadvantage of being time consuming, and
Even if black paper 001 is placed on the document table 003 side to block light, black paper 001 cannot completely absorb light, so 1
Not only does the potential of the unexposed area 009 (exposed area during the second imaging) decrease due to the second imaging, but also the potential of the original 009 decreases.
If it takes time to replace the sensor 4, the potential will also drop due to dark decay, resulting in drawbacks such as a significant image difference between the first and second imaging.

[Summary of the invention]

The present invention has an object of completely solving such drawbacks of the conventional art, and includes a plate material transporting means for transporting and stopping a plate material onto an exposure section, and a plate material transporting means that is wound around both ends of the exposure section in a roll shape and is individually rolled. first and second light-shielding curtains arranged, a light-shielding curtain driving means for drawing out and extending the outer light-shielding curtain onto the exposure section, and a setting means for forming a plurality of original images on the plate material; and a control device that drives the plate material transporting means and the light-shielding curtain driving means in a predetermined relationship based on instructions from the setting means, and is capable of automatically forming document images on multiple sides on the same plate material. The present invention provides an extremely effective exposure control device for a plate making machine.

〔Example〕

Hereinafter, details of the present invention will be explained with reference to figures showing examples.

Figure 2 is a side sectional view of the plate making machine, and shows the paper feed tray 1.
The sheet-like plate material 2 placed on top is moved by the suction mechanism 3
While the sheets are taken out one by one and fed by a group of rollers, they are charged by applying a high voltage in the charging section 4, and are then adsorbed and sent to the exposure section 5, whose interior is evacuated and has a negative pressure.

On the other hand, a document 7 placed on a document table 6 that can be freely pulled out to the side is illuminated by illumination lights 8 above each periphery, and is imaged by an imaging lens 10 via a mirror 9 and sent to an exposure section 5. The image is projected onto the plate material 2, thereby exposing the plate material 2 to light.

The exposed plate material 2 is transferred to the developing section 11 by a group of rollers.
After the latent image is developed there, it passes through a fixing section 12, where it is fixed and dried, and is sent to a delivery table 1 as a printing plate.

Here, a photoelectric plate length sensor (hereinafter referred to as MLS) 31 is located between the paper feed table 1 and the exposure section 5.
is provided, thereby detecting the plate material 2 and detecting the roller 1.
The total length of the plate material 2 is determined based on the number of revolutions 4, and a photoelectric stop sensor (hereinafter referred to as STS) 3 is installed at the center of the exposure section 5, which coincides with the optical axis 15.
2 is provided, which detects the leading edge of the plate material 2 being sent and determines the distance over which the plate material 2 will be transported thereafter.

On the other hand, a step motor (hereinafter referred to as SM ₁ ) 41 is provided to drive each roller group via a conveyor belt 17 and a chain 18 having a large number of ventilation holes in the exposure section 5, and upper and lower light-shielding films ( Step motors (hereinafter referred to as SM ₁ and SM ₂ ) 42 and 43 are provided to drive the BD _A and BD _B ) 19a and 19b via wires 20a and 20b, respectively.
The number of driving pulses given to these controls the rotational speed of each, and the transfer status of the plate material 2 and the BD _A 19
It is designed to control the feeding status of a, BD _B 19b.

FIG. 3 is a side view of the main parts when performing double plate making in which the same original image is exposed to different parts of the same plate material, and as shown in FIG. The plate material 2 is placed so that it coincides with the optical axis 15, and the position of the plate material 2 is determined in the exposure section 5 so that the center of the first exposed region coincides with the optical axis 15, and the unexposed region of the plate material 2 is placed on the BD. _A 19a provided above the exposed area 5 in the figure until it is masked.
Feeding length based on the winding shaft 21a of BD _A 19b
Only S _AE1 is driven in the direction of the arrow by SM ₂ 42.
When the BD _A 19a is fed out and a first exposure is performed, a first original image is formed on the front edge side of the plate material 2.

Next, as shown in B, while leaving the original 7 as it is, the plate material 2 is moved upward and downward in the figure by the SM ₁ 41 until the center of the second exposure area coincides with the optical axis 15, and the previous exposure of the plate material 2 is BD _B 19b provided below the exposed area 5 in the figure until the exposed area is masked.
Only the unwinding length S _BE1 is based on the winding shaft 21b of
If the SM ₃ 43 is driven in the direction of the arrow to feed out the BD _B 19b and then the second exposure is performed, the plate material 2
A second original image is also formed on the trailing edge side.

Note that BD _A 19a and BD _B 19b are made of a flexible light-shielding material, and their bases are wound around winding shafts 21a and 21b that are biased in the winding direction by springs, and their tips are formed into exposed parts. The wires 20a and 20b are attached to wires 20a and 20b provided on both sides of the wire 5, and are fed out in response to the drive of SM ₂ 42 and SM ₃ 43, and stopped at a predetermined position by DC excitation of these.
In response to the release of these stops, the winding shafts 21a, 21
b, and automatically returns to its original position.

Therefore, multiple plate making is performed without moving the original 7, and BD _A 19a, BD _B 19
b prevents exposure due to unnecessary scattered light.

FIG. 4 is a diagram showing the relationship between the original 7 and the plate material 2 in the case of sensor exposure in which the optical axis 15 and the center of the plate material 2 are aligned, and as shown in A, the optical axis 15 and the center of the plate material 2 are aligned. While aligning the center of the original 7, as shown in B, the total length L _M of the plate material 2 is determined, and the front edge 2a of the plate material 2 being transferred in the direction of the arrow is aligned with the optical axis 15 of the exposure section 5. After that, if L _M /2 is further transferred, the plate material 2 is stopped, and exposure is performed, the original image 5 is accurately placed in the center of the plate material 2 based on the actual total length L _M.
1 is formed.

That is, depending on one pulse given to SM ₁ 41,
The moving length of the plate material 2 fed by the roller 14 is
If L _SR is the number of pulses given to the SM ₁ 41 during the period when the MLS 31 is producing a detection output, then the total length L _M of the plate material 2 can be obtained from the following equation.

L _M = N × L _SR ...(1) Also, let L _PS be the moving length of the plate material 2 transported by the belt 17 according to one pulse applied to the SM ₁ 41, and calculate the mounting situation of the STS 32 and its sensitivity deviation. The offset value that corrects the error caused by
If _OFS , the transport length Z ₁ after the leading edge 2a of the plate material 2 coincides with the optical axis 15 and the number of pulses M ₁ required to be applied to the SM ₁ 41 for this transport are:
It is shown by the following formula.

Z ₁ =L _M /2+O _FS ...(2) M ₁ =Z ₁ /L _PS ...(3) Therefore, by STS32, the leading edge 2 of the plate material 2
After detecting a, it is sufficient to apply only the number of pulses in equation (3) to the SM ₁ 41 and then stop the SM ₁ 41.

FIG. 5 shows a fourth side exposure case in which a margin called a gripper is provided from the front edge 2a of the plate material 2 and a document image 51 is formed via this gripper width G _R.
This is a diagram similar to the one shown in the figure. First, as shown in A, one side of the original 7 is aligned with the reference position 52 set on the original platen 6, and as shown in B, the plate material 2 is moved in the direction of the arrow. After the leading edge 2a coincides with the optical axis 15,
After further moving the gripper width G _R and the distance D _OD between the optical axis 15 and the reference position 52, the plate material 2 is stopped and exposure is performed to form the original image 51 at a desired location.

Therefore, in this case, the front edge 2a of the plate material 2
The number of pulses M ₁ given to SM ₁ 41 after M 1 is detected by the STS 32 is given by the following equation.

M ₁ =D _OD +G _R +O _FS /L _PS ...(4) Figure 6 shows center double exposure in which the same document image is repeatedly exposed to symmetrical areas using the center 53 of plate material 2 as a reference. It is a diagram similar to FIG. 4 shown in FIG.
As shown in A, the center of the original 7 is aligned with the optical axis 15, and as shown in B1, the BD _A 1 is fed out by the length S _AE1 based on the winding shaft 21a in which the BD _A 19a is accommodated.
After feeding out the plate 9a, the front edge 2a of the plate material 2 is aligned with the optical axis 15.
After the center of the first original image 51a coincides with the optical axis 15, the plate material 2 is transported and stopped, and when the first exposure is performed, the first original image 51a
is formed.

Therefore, based on the central distance between the original images 51a and 51b shown in B2 as F _IG , and the overlapping light-shielding band caused by the feeding error between BD _A 19a and BD _B 19b, a colored band appears on the plate material 2 after development. In response to one pulse given to _the SM ₂ 42, the length of the BD _A 19a to be fed out is L _PA , and the distance from the winding axis 21a to the optical axis 15 is S _A.D.
Then, the distance between the leading edge of BD _A 19a and the optical axis 15 is
B _CK and the number of pulses S _A that must be applied to SM ₄₂ 42 are expressed by the following equation.

B _CK = F _IG /2 + D _EF ...... (5) S _A = S _AD - B _CK /L _PA ... (6) Also, when the plate material 2 is
₅ and the number of pulses M ₁ given to SM ₁ 41 after the STS 32 detects the leading edge 2a are:
It is given by the following equation.

Z ₀ =L _M /2-F _IG /2+O _FS =L _M -F _IG /2+O _FS ...(7) M ₁ =Z ₀ /L _PS ...(8) Then, as shown in B2, BD _A 19a After the BD _{B 19b} has been fed out, the plate material 2 is further transported _{by F IG and} stopped, and the second exposure is performed. A second original image 51b is formed.

Therefore, B _CK is given by equation (5), and the number of pulses S _B to be given to the SM ₃ 43 is calculated by dividing the distance between the winding axis 21 b and the optical axis 15 by S _BD , one pulse given to the SM ₃ 43 Accordingly, when the length at which the BD _B 19b is fed out is _LPB , it is expressed by the following equation.

S _B = S _BD - _{B CK} / L _PB ...(9) Also, the number of pulses M ₂ to be applied to the SM ₁ 41 required to transfer F _IG to the plate material 2 is:
It is shown by the following formula.

M ₂ =F _IG /L _PS ...(10) Figure 7 is a diagram similar to Figure 4 showing side double exposure in which repeated exposure is performed under the same conditions as Figure 5, and as shown in A, Reference position 52 on document table 6
Place the document 7 with one side aligned with B.
1, the unwinding length based on the winding shaft 21a
After determining S _AE2 and feeding out BD _A 19a according to this, the gripper width G _R and the distance between the optical axis 15 and the reference position 52 are determined after the front edge 2a of the plate material 2 coincides with the optical axis 15. By further transporting the plate material 2 by the amount of D _OD and stopping it, and performing the first exposure,
A first original image 51a is formed.

Here, in order to obtain the feeding length S _AE2 , since the width W of the original image 51a is unspecified, if BD _A 19a is indicated by an imaginary line in B2 and considered, the margin width between the original images 51a and 51b is calculated. When is _MNF , the distance X between the leading edge of BD _A 19a and the optical axis 15 is expressed by the following equation.

X=D _OD +M _NF /2-D _EF ...(11) Also, in B1 and B2, the following transfer causes relative movement of F _IG , and each BD _A 1
Since the leading edge distance of 9a is F _IG , the number of pulses S _A to SM ₂ 42 corresponding to the delivery length S _AE 2 is given by the following equation.

_{S A = S AD + _} Transfer plate material 2 further by F _IG , and
By performing the second exposure, the second original image 5
1b is formed.

That is, the distance Y between the optical axis 15 and the front edge of the BD _B 19b and the number of pulses S _B given to the SM ₃ 43 according to the delivery length S _BE2 are expressed by the following equation.

Y = D _OD + M _NF /2 + D _EF ... (13) S _B = S _BD - Y / L _PB ... (14) The number of pulses M ₂ given to SM ₁ 41 to transport the plate material 2 is ( 10) as shown by formula.

However, L _PS , S _AD , and S _BD in formulas (3) to (14) are
Errors may occur due to the dimensions and mounting conditions of the belt 17 and its stretched rollers, or due to the mounting conditions of 21a and 21b at the time of winding, and the mounting condition of the STS 32 may also differ from the optical axis 1.
5, and for plate material 2 and moving bodies such as BD _A 19 and BD _B 19b, SM ₁
In order to perform position control using 41 to SM ₃ 43, each error must be eliminated by correction.

Therefore, we first perform a test operation, perform plate making under specific conditions, and then obtain measured values that correspond to the assumed values determined in advance based on design predictions. ) to (4), control errors can be adjusted without any particular mechanical adjustment.

In other words, since L _PS is the basis of operation, it is a good idea to modify L _PS first.
For example, in a double exposure state, the original images 51a and 5 are placed on the plate material 2 with F _IG set to a value determined for correction.
1b is formed and developed, the distance between both images is actually measured to obtain the measured value S _TI , and the corrected L _PS is obtained using the following equation.

L _PS =S _TI /M ₂ (21) However, as shown in equation (10), M ₂ is the number of pulses given to SM ₁ 41 to transfer _FIG .

Next, it is necessary to make corrections according to the position of the _STS 32, and the side double exposure state shown in FIG. Manuscript image 5
The distance between the reference position 52 of the image corresponding to 1a and the leading edge 2a is actually measured to determine the actual measurement value S _CI , and the offset value _OFS is determined using the following equation.

_OFS = S _CI - D _OB (22) However, D _OB is the standard value of the distance between the optical axis 15 and the STS 32 determined by design standards.

Next, in order to correct S _AD of BD _A 19a, according to the state shown in Fig. 6, C _R and F _IG are set to the values determined for correction, only the first exposure is performed, and the first original image is Only the 51a side is exposed and developed, and the leading edge 2
Determine the photosensitive range width S _AI from a by actually measuring it, use the standard value S _AS determined by the design prediction, and determine the corrected S _AD using the following formula.

S _AD = S _ADS + (S _AI − S _AS ) ... (23) However, S _ADS is S _AD before correction.

In addition, in order to correct the S _BD of BD _B 19b, only the second exposure is performed in the state and conditions determined for correction as described above, and the second original image 51
Only the b side is exposed and developed, and the unexposed range width S _BI from the leading edge 2a is actually measured and determined. Using the same standard value S _BS as mentioned above and the S _BD before correction, S _BDS , the following formula is calculated. Find the modified S _BD by .

S _BD = S _BDS + (S _BS − S _BI ) ...(24) Therefore, after making the above corrections, use the values obtained thereby to calculate equations (3) to (14). If control is performed based on this, the position control of each moving body can be performed accurately.

Figure 8 is a block diagram of the electrical configuration of a processor such as a microprocessor (hereinafter referred to as CPU).
61, the interface (hereinafter referred to as I/
F) 62-64, ROM (Read Only Memory)
65, RAM (Random Access Memory) 66,
Pulse generators such as frequency dividers (hereinafter referred to as PG ₁ and PG ₂ ) 6
7, 68 and preset pull counters (hereinafter referred to as CT ₁ to CT ₅ ) 71 to 75 are arranged around them, and these are connected by bus bars 76 and 78, and the I/F
A keyboard (hereinafter referred to as KB) 79 and a display device (hereinafter referred to as DP) 80 such as a character display are connected to 62 .

In addition, I/F63 has MLS31, STS32
and the switch operated during adjustment (hereinafter referred to as
TSW) 33 is connected, and this switch sets the adjustment mode of the equipment, and when the adjustment is completed, this mode is canceled, and the adjusted value is protected from being easily changed, and the I/ F
64 includes drivers (hereinafter referred to as DR ₁ to _{DR 4} ) 81 to 64;
84 are connected, and the illumination lamps 8 and SM ₁ 41 to _{SM 3} 43, which are turned on during exposure, are individually driven through these.

On the other hand, PG ₁ 67 and PG 68 divide the clock pulses according to the control of the CPU 61, send out driving pulses with a predetermined period, and send them to DR ₂ 82 to _{DR 4} 84.
The signal is supplied to SM ₁ 41 to SM ₃ 43 via the 1000 to drive each of them, and is also supplied to CT ₁ 71 to _{CT 4} 74 to cause them to perform counting.

Note that the CPU 61 as a control unit uses the ROM 65
Execute the instructions stored in the I/F 62, 63
According to each input data via I/F 64, it performs control decisions and calculations while accessing the necessary data to RAM 66, and sends control signals via I/F 64 to control DR ₁ 81 to _{DR 4} to 84. While it has become a thing, according to the operation of KB79
The display data is sent to the DP 80 and displayed accordingly.

In addition, the CPU 61 presets count values to CT ₁ 71 to CT ₄ 74 according to data from KB 79, monitors the count values based on these subtraction counts, and also monitors the count values based on the registered counts of CT ₅ 75. A battery 85 is connected to the RAM 66, which backs up the data in the RAM 66 and retains it when the power is turned off. ing.

FIG. 9 is a flowchart of the control status by the CPU 61, in which CT ₁ 71 to CT ₅ 75 are cleared by "initialize" 101 following "start", and the above-mentioned S _ADS , S _BDS , etc. If uncorrected data is required, store the assumed value of the actual measured value predicted in the design in the ROM 65, transfer it to the ROM 65 at the time of initialization, and store the uncorrected data in the RAM 66. It needs to be stored. However, this operation requires RAM6
6 has been backed up, so for the first time,
This need only be done when accessing the RAM 66. Then, in response to the operation of KB79, “Start plate making?”
Judge 102, and if this is Y (YES), DR ₂
82 to start sending out pulses, perform "SM ₁ ON" 103, determine "Double exposure?" 111 in the same way as step 102, and if this is Y, "BD _A S _A calculation" 112 In addition, “S _A
Set "113" to CT ₁ , and DR ₃ 83
A pulse is sent to SM ₂ 42 under the control of SM 2 42 to set the state of "SM ₂ ON" 114, and by the subtraction count of CT ₁ 71 in response to this pulse, "CT ₁ =
0? "If 115 becomes Y, control DR ₃ 83 and
SM ₂ 42 is in DC excitation state and "SM ₂ brake" 1
16, and the feeding of BD _A 19a is completed.

Next, in response to the operation of KB79, if "Center plate making?" 121 is Y, "L _M calculation" 122 is performed and then "M ₁ calculation" 123 is performed to detect the leading edge 2a of plate material 2. “STS on?”124
If it becomes Y, “set M ₁ to CT ₂ and start”
125, the CT ₂ 72 subtracts and counts the pulses for the SM ₁ 41, and when the ``CT <sub>2</sub> = 0?'' 126 becomes Y, the pulse transmission is stopped under the control of the DR <sub>2</sub> 82, and the ``SM ₁ off'' 127 is executed. The plate material 2 is thereby stopped at a predetermined position.

Then, in response to the operation of TSW33 and KB79, if "Cancel first exposure?" 131 is not Y but is N (NO), "Start exposure timer" 1 configured in software in CPU 61 is sent.
32, and also controls the DR ₁ 81 to turn on the exposure lamp 133 for the illumination lamp 8.
When "Exposure timer time up?" 134 becomes Y, "Exposure lamp off" 135 is performed under the control of DR ₁ 81.

Also, in the same way as step 111, "double exposure?" 141 is determined again, and if this is Y, DR ₃
83 to turn off the DC excitation of SM ₂ 42, perform "BD _A return" 42, and perform " _SB calculation of BD _B " 14.
After performing step 3, “Set S _B to CT ₃ ” 144
After performing this, the DR ₄ 84 is controlled to send a pulse to the SM ₃ 43 to perform "SM ₃ ON" 145, and by counting the subtraction of this pulse, "CT ₃ = 0?" 1
When 46 becomes Y, "SM ₃ brake" 147 is performed by DC excitation, and the feeding of BD _B 19b is completed.

Then, as shown in equation (10), “M ₂ =F _IG /L _PS ”15
1 is performed according to the F _IG data given from the KB73 and stored in the RAM 66, and the L _PS data previously stored in the RAM 66, and "Set M ₂ to CT ₄ " 152 is executed. After that, perform "SM ₁ on" 153 again and perform subtraction count according to the pulse of this CT ₄ 74
When the count value of "CT ₄ = 0?" 154 becomes Y, "SM ₁ off" 155 is executed to stop the plate material 2 at the second exposure position.

Then, as in step 131, "Cancel second exposure?" 161 is determined, and if this is N, as in steps 132 to 135, "Start exposure timer" is determined.
162 to "Exposure lamp off" 165 are repeated, and the control for DR ₄ 84 causes the step to turn off.
After performing “BD _B return” 171 in the same way as 142,
"SM ₁ ON" 172 is performed under the control of the DR ₂ 82, and the process moves to "post-exposure processing" 171 such as development and fixing, and steps 102 and subsequent steps are repeated.

FIG. 10 is a flowchart showing the details of step 112, in which the old and new data of the actual measured value S _AI stored in the RAM 66 according to the adjustment operation described later are compared to ask "Is there a change in S _AI ?" 201 If this is Y, RAM is determined according to equation (23).
According to the data in step 66 and using the new measured value S _AI , calculate “S _AD = S _ADS + (S _AI − S _AS )” 202, and as in step 121, “sensor plate making?” 20
3, and depending on Y of this, according to the data in RAM66, "B _CK = (F _IG / 2) + D _EF " of formula (5)
211, and “S _A = (S _AD −B _CK )/ in equation (6)
_LPA''212 is calculated to obtain S _A and stored in the RAM 66.

Moreover, when step 203 is N, "X=D _OD + (M _NF /2) - D _EF " 221 of equation (11), and
(12) "S _A = (S _AD + X-F _IG )/L _PA "222
is calculated and S _A is stored in the RAM 66.

In addition, S _ADS , L _PA , etc. are sent to RAM66 in advance.
S _AS , D _EF , D _OD , M _NF , etc. are similarly stored in the ROM 65, and S _AI , S _IG , etc. are given from the KB79 and stored in the RAM 66.

FIG. 11 is a flowchart showing the details of step 122. When the leading edge 2a of the plate material 2 being fed is detected, "MLS ON?" 301 becomes Y.
In response to this, “CT ₅ start” 302 is performed,
The CT ₅ 75 registers and counts the number of pulses given to the SM ₁ 41, and if _the "MLS off?" , performs "read count value N" 311 of this, calculates L _M by calculating "L _M =N×L _SR " 312 as shown in equation (1), and stores this in the RAM 66.

Note that data stored in the RAM 66 is used for the _LSR .

FIG. 12 is a flowchart showing the details of step 123, in which a comparison of the old and new data of the actual measured value _STI stored in the RAM 66 according to the adjustment operation determines "Is there a change in _STI ?"401; If this is Y, use the new measured value S _TI and calculate “L _PS = S _TI /M ₂ ”402 using equation (21),
Similar to step 401, “Is there a change in S _CI ?” 411
, and depending on Y of this, “O _FS =
S _CI −D _OB ” 412 calculation is performed.

Then, do center plate making like steps 121 and 111? "421" and "double exposure?" ”422, and if both are Y, “Z ₀ =
[(L _M −F _IG )/2]+O _FS ”431 and “M ₁ =Z ₀ /L _PS ”432 in equation (8) are calculated, while depending on N in step 422, (2 ) equation “Z ₁ = (L _M /2)
+O _FS ”441, and “M ₁ = Z ₁ /L _PS ” in equation (3)
422 and when step 421 is N, (4)
“M ₁ = (D _OD + G _R + O _FS ) / L _PS ” according to the formula 451
After calculating, M ₁ is stored in the RAM 66.

In addition, M ₂ , L _M , L _PS , etc. are stored in the RAM 66, and D _OB , L PS, etc.
D _OD, etc. are stored in the ROM65, and
S _TI , S _CI , S _IG , G _R etc. are changed according to the operation of KB79.
Stored in RAM66.

FIG. 13 is a flowchart showing the details of step 143, in which it is determined whether there is a change in S _BI by comparing the old and new data of the actual measured value S _BI stored in the RAM 66 according to the adjustment operation. , if this is Y, then “S _BD = S _BDS +
(S _BS - S _BI )" 502 is calculated, and as in step 121, "Center plate making? ”503 and this Y
According to equation (5), “B _CK = (F _IG /2) + D _EF ”51
1, and “S _B = (S _BD − B _CK )/L _PB ”5 in equation (9)
12, and when step 503 is N,
According to formula (13), “Y=D _OC + (M _NF /2) + D _EF ”5
21, and “S _B = (S _BD −
Y)/L _PB ”522 is calculated, S _B is calculated, and RAM is calculated.
66.

Note that the storage status of each data in the RAM 6 is the same as that shown in FIG.

FIG. 14 is a flowchart during adjustment,
When TSW33 is turned on, it becomes “adjustment mode”.
“Item setting” 6 for adjustment using the selection key of KB79
01 as a code, the item display section of the DP80 will display "item display" 602 using the corresponding code, and the number display section of the DP80 will display the corresponding "hypothetical value display" 603 in the RAM 66.
This is done by reading from.

Next, as shown in FIG. 9, "test plate making" 611 is performed, and as described above, the actual measured value corresponding to the assumed value displayed in step 603 is obtained, and in response to this, "actual value input" 62 is performed using the numerical keys of KB79.
1, “Assumed value = Actual value?” 622 Y
Assuming that, the display in step 603 will be “updated to actual measured value display” 623, and this “store measured value to RAM” 624 will be performed,
“TSW Off?” Step 601 via N of 631
Repeat the following.

In addition, the L _PS adjustment is from 2860 to 3060 m/m, in 0.1 m/m steps, depending on the code "STP" setting.
The position adjustment of STS32 is from 0 to 400m/m, in 0.1m/m steps, by setting the code “CNT”.
Adjustment of L _PA and L _PB is from 189 to 199 m/m and by setting the code “SDU” and “SDD”.
Each is to be carried out within a range and accuracy of 185 to 195 m/m and 1.0 m/m steps.

Furthermore, if the displayed hypothetical value and the actual measured value match, step 621 can be omitted.

In addition, when adjusting the position of STS32, adjust the center value.
200m/m, and the positive and negative deviations are calculated from the actual measured value using the center value as a reference, and KB
79, the keys "+" and "-" are omitted.

In addition, assumed values are displayed, which can be used as a guideline for actual measurements.

Therefore, mechanical errors can be easily corrected, and there is no need for a special correction value setting switch, thereby simplifying the configuration and improving adjustment accuracy.

Further, the exposure area on the plate material 2 can be precisely regulated, and even if there is a dimensional deviation of the plate material 2, the original image can be reliably formed on the predetermined area, and double exposure can be easily and accurately performed. , BD _A 19a,
BD _B 19b prevents unnecessary random light from entering, producing a plate material with good contrast, and
The plate making speed is generally improved.

However, in calculating L _M , if there is a dimensional deviation in roller 14, an error will occur, so in this case, roller 1
Although the dimensions of roller 14 are made highly accurate to prevent errors from occurring, the dimensional deviation of roller 14 can also be adjusted by the same means as described above, depending on the situation.

Furthermore, as MLS31 and STS32, other sensors besides photoelectric type may be used, and BD _A 19a,
The same applies to a single BD _B 19b that moves around the exposure section 5 and stops at a predetermined position to perform masking, and a dedicated one that combines various logic circuits instead of the CPU 61. may be used, PG ₁ 67, PG ₂ 68, CT ₁ 71 to _{CT 5}
It is also optional to configure 75 in software.

In addition, in FIGS. 9 to 14, various modifications can be made, such as replacing the steps or omitting unnecessary steps, depending on the situation.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, there is no need to move the original on the original table, and therefore the operation of setting the original is simple and easy, and can be done in a short time, and the original does not need to be moved. Therefore, the plate-making speed is fast, the image position accuracy is good, and there is little difference in the images between the first and second imaging, and a high-quality original plate can be manufactured.

Also, unlike the method of placing black paper on the original surface, the non-exposed side of the plate material is directly shielded from light by a light-shielding curtain, so the second exposed area is not affected by the first exposure, and double plate making Remarkable effects can be obtained in various plate-making machines that perform this process.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a conventional plate-making situation, FIG. 7th
The figure shows the exposure relationship between the original and the plate material, FIG. 8 is a block diagram of the electrical configuration, and FIGS. 9 to 14 are flowcharts showing the control situation. 2... Plate material, 2a... Leading edge, 4... Charged part, 5
...Exposure section, 6...Original table, 7...Original, 8...
Lighting lamp, 9...mirror, 10...lens, 11...
...Developing section, 12... Fixing section, 14... Roller, 1
5...Optical axis, 17...Belt, 18...Chain, 19a...BD _A (light shielding film), 19b...BD _B
(light shielding film), 20a, 20b...wire, 21a,
21b... Winding shaft, 31... MLS (plate material length sensor), 32... STS (stop sensor), 33... TSW
(switch), 41...SM ₁ (step motor), 4
2...SM ₂ (step motor), 43... SM ₃ (step motor), 51, 51a, 51b... original image, 52... reference position, 53... center, 61...
CPU (processor), 65...ROM, 66...
RAM (memory), 67, 68...PG ₁ , PG ₂ (pulse generator), 71 to 75...CT ₁ to _{CT 5} (counter), 79...KB (keyboard), 80...DP
(display), 81 to 84...DR ₁ to DR ₄ (driver).

Claims (1)

[Scope of Claims] 1. Plate material transport means for transporting and stopping a plate material onto an exposure section; and first and second plate material wound around both ends of the exposure section and disposed individually. a light-shielding film; first and second light-shielding film driving means for selectively drawing out the first and second light-shielding films; a plate sensor disposed in the exposure section; and setting conditions for two-imposition. a calculation means for calculating the first and second exposure positions and the extension heights of the first and second light-shielding films based on the settings of the setting means; After detecting the leading edge of the plate material, the plate material is transported to the first exposure position and stopped, and the first light shielding film is fed out by the length of the first light shielding film, and the second exposure position of the plate material is moved. A first exposure is performed with light shielded, and then
Returning the first light-shielding film and transporting the plate material to the second exposure position and stopping it, and also feeding out the second light-shielding film by the length of the feed-out length to shield the first exposure position of the plate material from light. 1. An exposure control device for a plate-making machine, comprising a control means for performing a second exposure, and for applying two original images to the same plate material while the original is stopped.