JPH0712655B2 - Plate making position control device of plate making machine - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a plate making machine used for making a printing plate for printing, when the original image is exposed to the plate material, The present invention relates to a control device that regulates the position of a plate material by matching the optical axis of an optical system.

[Prior art]

When exposure is performed by aligning the center of the plate material with the optical axis of the optical system to form a document image at the center of the plate material or at each of the target portions with reference to the center, the plate material is exposed. In the past, the plate material was stopped at the exposure part according to the nominal size of the plate material, and an error occurred due to the actual dimensional deviation of the plate material. This causes a defect that a document image is not formed on the portion to be specified.

[Outline of Invention]

The present invention has an object of fundamentally solving the above-mentioned drawbacks, and a plate for detecting the presence of a moving plate material when the plate material (2) is fed to an exposure section (5) by a roller (14). A material length sensor (31) and a step motor (41) that rotationally drives a roller while the plate material length sensor detects the presence of the plate material.
The plate material length measuring means (61) for measuring the length of the plate material in the moving direction from the number of pulses supplied to the plate material, the stop sensor (32) provided at the position of the optical axis of the exposure section, and the plate material length. Based on the length L _M , the transport length Z _{1 of the} leading edge (2a) of the plate material from the time when the leading edge (2a) of the plate material passes the position of the optical axis until it stops, and the step motor that feeds the plate material in the exposure unit From the length L _PS of sending the plate material in pulses, the pulse number calculation means (61) that calculates Z ₁ / L _PS to obtain the pulse number M ₁ and the stop sensor detects the leading edge of the plate material. , And drive control means (61, 82) for driving the step motor by the number of pulses M ₁ .

〔Example〕

Hereinafter, the details of the present invention will be described with reference to the drawings illustrating examples.

FIG. 1 is a side cross-sectional view of a plate making machine. Sheet-shaped plate materials 2 placed on a paper feed tray 1 are taken out one by one by a suction mechanism 3 and fed by a group of rollers. On the way, it is charged by the application of a high voltage in the charging section 4, and the inside of the charging section 4 is evacuated and transferred while being adsorbed to the exposure section 5 which has a negative pressure.

On the other hand, the document 7 placed on the document table 6 that can be pulled out to the side is illuminated by the illumination lamp 8 above each periphery, and is also imaged by the imaging lens 10 via the mirror 9 to be exposed by the exposure unit 5.
And the plate material 2 is exposed.

The exposed plate material 2 is sent to the developing unit 11 by a roller group,
After the latent image is developed here, the latent image passes through the fixing unit 12, whereby the fixing and drying are performed, and the delivery table 13
It is supposed to be sent out as a printing plate.

Here, a photoelectric plate material length sensor (hereinafter, referred to as MLS) 31 is provided between the paper feed table 1 and the exposure section 5, and the plate is detected by the plate material 2 and the rotation speed of the roller 14 to detect the plate material. The total length of the material 2 is obtained, and a photoelectric stop sensor (hereinafter referred to as STS) 32 is provided in the central portion that coincides with the optical axis 15 of the exposure unit 5.
Is provided, whereby the front edge of the plate material 2 sent in is detected, and the distance to transfer the plate material 2 thereafter is determined.

On the other hand, a step motor (hereinafter referred to as SM ₁ ) 41 for driving each roller group through a conveyor belt 17 and a chain 18 having a large number of vent holes of the exposure section 5 is provided, and upper and lower light shielding films ( Hereinafter, BD _A , BD _B ) step motors (hereinafter SM ₂ , S) for driving 19a, 19b via wires 20a, 20b, respectively.
M ₃ ) 42 and 43 are provided, and the number of drive pulses given to these controls the respective rotation speeds to control the transfer status of the plate material 2 and the feeding status of BD _A 19a, BD _B 19b. ing.

FIG. 2 is a side view of an essential part in the case of performing double plate making in which the same original image is individually exposed to different portions of the same plate material. As shown in FIG. The platen 2 is placed with the center of the plate aligned with the optical axis 15, while the position of the plate material 2 is determined in the exposure part 5 so that the center of the first exposed part coincides with the optical axis 15. To BD _A 19a
BD provided above the exposure unit 5 in the figure until masked by
_A 19a Feeding length S _{AE1 based on} the winding shaft 21a only, SM ₂ 42
Drive in the direction of the arrow to feed BD _A 19a,
When the exposure is performed once, the first original image is formed on the front edge side of the plate material 2.

Then, as shown in (B), the original 7 is left as it is, and the plate material 2 is moved downwards in the figure by the SM ₁ 41 until the center of the second exposure portion coincides with the optical axis 15. Until the previously exposed portion is masked, the feeding length S based on the winding shaft 21b of the BD _B 19b provided below the exposure unit 5 in the figure
_BE1 only from out Repetitive a BD _B 19b is driven in the arrow direction by SM ₃ 43, by performing the second exposure, the second original image to the rear edge of the plate material 2 is formed.

BD _A 19a and BD _B 19b are made of a flexible light-shielding material, and the base is wound on the winding shafts 21a and 21b biased in the winding direction by a spring, and the tip is exposed to light. It is locked to the wires 20a, 20b provided on both sides of 5, respectively, and is fed out in response to the drive of SM ₂ 42, SM ₃ 43, and it is stopped at a predetermined position by the DC excitation of these, and the stop is released. According to the above, it is wound on the winding shafts 21a and 21b and automatically returns.

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

FIG. 3 is a diagram showing the relationship between the original 7 and the plate material 2 in the case of center exposure in which exposure is performed with the optical axis 15 and the center of the plate material 2 aligned, and as shown in FIG. While aligning 15 and the center of the original 7, as shown in (B), the total length L _{M of the} plate material 2
Then, after the front edge 2a of the plate material 2 transferred in the direction of the arrow coincides with the optical axis 15 of the exposure unit 5, further L _M / 2 is transferred and the plate material 2 is stopped to perform the exposure. If done, the original image 51 is accurately formed on the central portion of the plate material 2 based on the actual total length L _M.

That is, the moving length of the plate material 2 fed by the roller 14 in response to one pulse applied to the SM ₁ 41 is L _SR, and the number of pulses applied to the SM ₁ 41 during the period when the detection output is generated by the MLS 31 is N. Then, the total length L _M of the plate material 2 is obtained by the following equation.

L _M = N × L _SR (1) In addition, the movement length of the plate material 2 transferred by the belt 17 in response to one pulse given to the SM ₁ 41 is L _PS, and the mounting status of the STS 32 and its sensitivity deviation if the offset value to correct the errors occur through cowpea at equal and O _FS, the plate material 2 front edge 2a is an optical axis 15
Transfer length Z ₁ after matching with, and required for this transfer
The number of pulses M ₁ that must be given to SM ₁ 41 is given by the following equation.

Was but connexion, after detecting the leading edge 2a of the plate material 2 by STS32, the SM ₁ 41 (3) after having received only the number of pulses of the formula, SM ₁
41 should be stopped.

Figure 4 is provided with a margin called Guritsupa from the leading edge 2a of the plate material 2, there in the same figure and FIG. 3 showing the Ba応side exposure to form the original image 51 through the Guritsupa width G _R First,
As shown in (A), one side of the original 7 is aligned with the reference position 52 defined on the original table 6, while as shown in (B), the front edge 2a of the plate material 2 transferred in the direction of the arrow is the optical axis. After matching with 15, the gripper width G _R and the distance between the optical axis 15 and the reference position 52
When the _DOD is further transferred, the plate material 2 is stopped and exposure is performed, an original image 51 is formed at a desired portion.

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

FIG. 5 is a view similar to FIG. 3 showing center double exposure in which the same original image is repeatedly exposed from the plate material 2 to the center 53 as a reference, and as shown in FIG. While aligning the center of 7 with the optical axis 15, as shown in (B1), BD
Feeding length S _{AE1 based} on the winding shaft 21a that houses _A 19a
After feeding BD _A 19a only, after the front edge 2a of the plate material 2 coincides with the optical axis 15, the plate material 2 is transferred and stopped until the center of the first original image 51a coincides with the optical axis 15. Then, if the first exposure is performed, the first original image 51a is formed.

Therefore, the center interval between the original images 51a and 51b shown in (B2)
Based on the overlapping light-shielding band caused by the feeding error between F _IG , BD _A 19a and BD _B 19b, the overlapping light-shielding prevention width D _EF , SM ₂ is provided to prevent the appearance of the colored belt on the plate material 2 after development. In accordance with one pulse given to 42, the payout length of BD _A 19a is taken as L _PA ,
If the distance between the winding axis 21a and the optical axis 15 is S _AD , the distance B _CK between the front edge of BD _A 19a and the optical axis 15 and the number of pulses S _A that must be given to SM ₂ 42 are Indicated by.

Also, the distance between the front edge 2a and the optical axis 15 when the plate material 2 is stopped
Z ₀ and the number of pulses H ₁ given to SM ₁ 41 after STS 32 detects the leading edge 2a are given by the following equation.

Then, as shown in (B2), along with returning BD _A 19a,
Only the _pay- out length S _{BE1 based} on the winding axis 21b of BD _B 19b BD _B 19
After being fed to b, the plate material 2 is further transported by F _{IG and} stopped, and a second exposure is performed to form a second original image 51b.

Therefore, B _CK is given by equation (5) and S
The number of Bells S _B to be given to M ₃ 43 is determined by the winding axis 21b and the optical axis 15
The distance between the response to one pulse to be supplied to _{S BD, SM 3 43, BD} B 19b
When the payout length for paying out is L _PB , it is shown by the following formula.

In addition, S required to transfer the F _{IG component} to plate material 2
The number of pulses M ₂ to be given to M ₁ 41 is shown by the following equation.

FIG. 6 is a view similar to FIG. 3 showing side double exposure in which repetitive exposure is performed under the same conditions as in FIG.
As shown in (B1), while the original 7 is placed with one side aligned with the reference position 52 on the original table 6, as shown in (B1).
After the payout length S _AE2 is determined based on a and BD _A 19a is paid out according to this, after the front edge 2a of the plate material 2 coincides with the optical axis 15, the gripper width G _R and the optical axis 15 Between reference position 52 and
The first original image 51a is formed by further transporting the plate material 2 by the amount of D _OD and stopping it, and performing the first exposure.

Here, in order to obtain the feeding length S _AE2 , since the width W of the original image 51a is not specified, BD _A 1 is drawn by the virtual line in (B2).
Considering 9a, when the margin width between the original images 51a and 51b is M _NF , the distance X between the front edge of BD _A 19a and the optical axis 15 is given by the following equation. For (B1) and (B2),
Since the relative movement of F _IG occurs, and the leading edge distance of each BD _A 19a is F _IG , the number of pulses S _A to SM ₂ 42 corresponding to the payout length S _AE2 is given by the following equation.

Then, as in Fig. 5, BD _A 19a is returned and
After feeding BD _A 19b and feeding length S _BE2 , press plate material 2
The second original image 51b is formed by further moving by _IG and performing the second exposure.

That is, the distance Y between the optical axis 15 and the front edge of the BD _B 19b, and
Pulse number S _B to give to SM ₃ 43 in accordance with the feeding length S _BE2 is represented by the following equation.

The number of pulses M ₂ given to SM ₁ 41 to transfer plate material ₂
Is as shown by equation (10).

However, L _PS , S _AD , S _{ED in the} equations (3) to (14) is the belt 1
7, and due to the size and installation condition of the tensioned roller, or due to the installation condition of the winding shafts 21a, 21b, etc., the installation condition of the STS 32 is completely different from that of the optical axis 15. The position is not necessarily the same, and in order to perform position control with SM ₁ 41 to SM ₃ 43 with respect to the plate material 2 and moving bodies such as BD _A 19a, BD _B 19b, etc., each error is deleted by correction. And have to.

Therefore, the test operation is performed first, and then the plate is made under the specific conditions, and the measured value corresponding to the assumed value set in advance on the design side is obtained. By correcting the calculation of the expressions (2) to (4), it is possible to adjust the control error without performing any mechanical adjustment.

In other words, since L _PS is the basis of operation, it is a good idea to correct L _PS first.For example, in double exposure, set F _IG to the value specified for correction and The original images 51a and 51b are formed on the material 2 and developed, and the interval between both images is measured to obtain the measured value S _TI, and L _PS corrected by the following formula
Ask for.

However, as shown in equation (10), M ₂ is S to transfer the F _IG.
It is the number of pulses given to M ₁ 41.

Next, it is necessary to make corrections according to the position of STS32.
The original images 51a and 51b are formed and developed under the condition of G _R = 0, and then the distance between the reference position 52 and the leading edge 2a of the image corresponding to the original image 51a is measured to obtain the measured value S _CI. Request offset value O _FS by formula.

_{O FS = S CI -D OB ......} (22) However, D _OB is an optical axis 15 defined by the design criteria and STS
It is the interval reference value with 32.

Next, in order to correct the S _{AD of} BD _A 19a, according to the state of FIG. 6, G _R and F _IG are set to the values determined for correction, and only the first exposure is performed, and the first original image Only the 51a side is exposed and developed, the exposure range width S _AI from the leading edge 2a is measured and obtained, and the standard value S _AS determined by the design prediction is used, and the S _AD corrected by the following equation is calculated. Ask.

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

Further, in order to correct the S _{BD of the} BD _B 19b, similarly to the above, only the second exposure is performed under the conditions and conditions set for the correction, and only the second original image 51b side is exposed and developed. Then, the non-photosensitive range width S _BI from the front edge 2a is measured and obtained, and the same standard value S _BS and S _BDS that is S _BS before correction are used to obtain S _BD corrected by the following equation.

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

FIG. 7 is a block diagram of the electrical configuration, centering on a processor (hereinafter, CPU) 61 such as a microprocessor.
Interfaces (hereinafter I / F) 62 to 64, ROM (Read Onl
y Memory.) 65, RAM (Random Access Memory.) 66, pulse generators such as frequency dividers (hereinafter, PG ₁ and PG ₂ ) 67 and 68, and
Pre-settable counters (CT _{1 to} CT ₅ ) 71 to 75 are arranged in the periphery, and these are connected by buses 76 and 78.
A keyboard (hereinafter referred to as KB) 79 and a display device (hereinafter referred to as DP) 80 such as a character display device are connected to 62.

In addition, the I / F 63 is connected to the MLS31, STS32 and a switch (hereinafter, TSW) 33 that is operated during adjustment. With this switch, the adjustment mode of the equipment is set, and when the adjustment is completed, this The mode is canceled and the adjusted value is protected so that it cannot be changed.
Driver (hereinafter, DR _{1 to} DR ₄ ) 81 to 84 are connected, and an illumination lamp 8 and SM ₁ 41 to SM ₃ 43 which are turned on during exposure are connected through these.
Is driven by each individual.

On the other hand, the PG ₁ 67 and PG ₂ 68 divide the clock pulse according to the control of the CPU 61 and send out a driving pulse of a predetermined cycle, which is sent to SM ₁ 41 to SM via DR ₂ 82 to DR ₄ 84. ₃ applied to 43, it drives the by connexion respectively to give the CT ₁ 71~CT ₄ 74, and summer as for these perform counting.

The CPU 61 as a control unit executes the instructions stored in the ROM 65, and makes judgments and calculations for control while accessing necessary data to the RAM 66 according to each input data via the I / Fs 62 and 63. The control signal is sent via I / F 64 to control DR ₁ 81 to DR ₄ 84, while KB
According to the operation of 79, the display data is sent to the DP 80, and the display is performed by this.

In addition, CPU 61 is a count value Purisetsuto to CT ₁ 71~CT ₄ 74 according to the data from KB79, monitors the count value of these operations counts, the count value of bankruptcy count CT ₅ 75 It monitors and controls the start, stop, and clear of the counting operation for these. A battery 85 is connected to RAM66, which backs up when the power is turned off.
It is supposed to hold the data in 6.

FIG. 8 is a flow chart of the control status by the CPU 61, and the CT is performed by "Initialize" 101 following "Start".
₁ 71 to CT ₅ 75 is cleared. The above S _ADS , S
If you need uncorrected data such as _BDS , ROM65
Store the hypothetical value of the actual measurement value predicted in the design,
At the time of initialization, it is necessary to transfer the data to ROM65 and store the uncorrected data in ROM66. However, this operation is performed only when accessing the RAM 66 for the first time because the RAM 66 is backed up.

Then, in response to the operation of KB79, determine "Start plate making?" 102,
This starts the transmission of pulses by controlling the DR ₂ 82 if the Y (YES) performs "SM ₁ on" 103, it is determined similarly "double exposure?" 111 and step 102, there it is in Y For example, “BD _A S _A
After performing the calculation "112, perform" S _{A set} to CT ₁ "113, and by sending a pulse to SM ₂ 42 under the control of DR ₃ 83, set" SM ₂ on "114 state. If "CT ₁ = 0?" 115 becomes Y by subtraction count of CT ₁ 71 according to this pulse, control DR ₃ 83 to put SM ₂ 42 in the DC excitation state and perform "SM ₂ brake" 116, The feeding of BD _A 19a is completed.

Then, in response to the operation of KB73, if "Center plate making?" 121 is Y, "L _M calculation" 122 is performed, then "M ₁ calculation" 123 is performed, and the leading edge 2a of the plate material 2 is detected. If STS is on? "124 is Y," Set M ₁ to CT ₂ and start "125, C
T ₂ 72 counts down the pulse for SM ₁ 41 and counts as “CT ₂ = 0?” 1
When 26 becomes Y, the pulse output is stopped by the control of DR ₂ 82 and "SM ₁ off" 127 is performed, whereby the plate material 2 is stopped at a predetermined position.

Then, depending on the operation of TSW33 and the operation of KB79, if "1st exposure stop?" 131 is not Y and N (NO), "Exposure timer start" 132 configured in software in CPU 61 is executed. At the same time, the DR ₁ 81 is controlled to perform the “exposure lamp on” 133 for the illumination lamp 8 and the “exposure timer /
"If 134 and Y, the control of the DR ₁ 81" Taimuatsupu? Performing exposure lamp off "135.

Also, again, it is likewise "double exposure?" 141 determines that step 111, which is turned off the DC excitation of SM ₂ 42 controls the DR ₃ 83 If Y der performs "BD _A return" 142, “ _{B B} S _B Calculation” 1
After performing step 43, “S _{B is set} to CT ₃ ” 144, then DR ₄ 84 is controlled to send a pulse to SM ₃ 43 and “SM ₃ on” 145 is performed. "CT by subtraction count
₃ = 0? When "146" becomes Y, "SM ₃ brake" 147 is performed by DC excitation, and feeding of BD _B 19b is completed.

Then, as shown in the equation (10), the calculation of “M ₂ = F _IG / L _PS ” 151 is performed, and the data of F _IG given from KB73 and stored in RAM66, and the L _PS previously stored in RAM66 are stored. The count value of CT ₄ 74, which performs "M ₂ on CT ₄ set" 152, then "SM ₁ on" 153 again, and subtracts and counts according to this pulse. "C
If T ₄ = 0? "Y of 154", "SM ₁ off" 155 causes plate material 2
To the second exposure position.

Then, as in step 131, "stop second exposure?" 161 is determined. If this is N, as in steps 132 to 135,
"Exposure timer start" 162 to "Exposure lamp off" 165
Is repeated, and step 1 is controlled by the DR ₄ 84.
After performing "BD _B return" 171 as in 42, "SM ₁ ON" 172 is performed by the control of DR ₂ 82, and the process proceeds to "post-exposure processing" 171 such as development and fixing, and steps 102 and thereafter are performed. Repeat.

FIG. 9 is a flow chart showing the details of the step 112, and "S _AI has changed depending on the old and new data of the measured value S _AI stored in the RAM 66 according to the adjustment operation described later.
If "201" is judged and this is Y, RAM is calculated by the equation (23).
According to the data in 66 and using the new measured value S _AI ,
_AD = S _ADS + (S _AI- S _AS ) "202 is calculated and" Center plate making? "203 is judged in the same manner as in step 121. Depending on Y of this, formula (5) is calculated according to the data in RAM66. “B _CK = (F _IG /
2) + D _EF "211 and" S _A = (S _AD −B _CK ) / in equation (6).
Calculate L _PA "212, find S _A , and store it in RAM66.

When step 203 is N, "X = D _OD " in the equation (11).
+ (M _NF / 2) -D _EF "221 and" S _A = (S
_AD × X−F _IG ) / L _PA “222 is calculated and S _A is stored in RAM66.

In addition, S _ADS , L _PA , etc. Are stored in RAM66 in advance, S _AS , D _EF , D _OD ,
M _NF, etc. are also stored in ROM65 and S _AI , F _IG
Etc. are given from KB79 and stored in RAM66.

FIG. 10 is a flow chart showing the details of the step 122. When the front edge 2a of the plate material 2 to be fed is detected, "MLS ON?" 301 becomes Y, and accordingly "CT ₅ start". 302 is performed, CT ₅ 75 counts up the number of pulses given to SM ₁ 41, and “MLS off? 30
If 3 becomes Y, perform "CT ₅ stop" 304, then perform "Count value N reading" 311 of this, and then
As shown in the equation (1), L _M is obtained by the calculation of “L _M = N × L _SR ” 312, and this is stored in the RAM 66.

The data stored in the RAM 66 is used as L _SR .

FIG. 11 is a flow chart showing the details of the step 123. The actual measurement value S stored in the RAM 66 in response to the adjusting operation is shown in FIG.
_{Based on the} comparison of old and new data of _TI, it is determined that "STI has changed?" 401, and if this is Y, the new measured value _STI is used (2
According to the formula (1), "L _PS = S _TI / M ₂ " 402 is calculated, and like step 401, "S _CI has changed?" 411 is determined, and depending on Y of this, the formula (22) "O _FC = S _CI -D _OS " 412 is calculated.

Then, as in steps 121 and 111, center plate making? "42
If 1 and “double exposure?” 422 are judged, and both are Y, “Z ₀ = [(L _M −F _IG ) / 2] + O _FS “ 431, and (8 ) Equation "M ₁ = Z ₀ / L _PS " 432 is calculated, while "Z ₁ = (L _M / 2)" in Equation (2) is calculated depending on N of step 422.
+ O _FS "441 and" M ₁ = Z ₁ / L _PS "442 of the formula (3) are calculated, and when step 421 is N," M _{1 of the} formula (4) is calculated.
_{= (D OD + G R +} O FS) / L PS "451 the top of operation, the M ₁ RAM 66
Store to.

Note that M ₂ , L _M , L _PS , etc. are stored in RAM 66, D _OB , D _OD, etc. are stored in ROM 65, and S _TI , S _CI , F _IG , G _R, etc. are stored in KB 79. It is stored in RAM66 according to.

FIG. 12 is a flow chart showing the details of the step 143, and “S _BI has changed?” 501 by comparing the old and new data of the measured value S _BI stored in the RAM 66 according to the adjusting operation.
If this is Y, and if this is Y, then “S _BD = S
_{BDS + (S BS -S BI)} "502 computes, step 121 Like""determines 503, in response thereto Y (5) expression of the" center plate _{making? B CK = (F IG /} 2 ) + D _EF "511, and
In the equation (9), “S _B = (S _BD −B _CK ) / L _PB “ 512 is calculated, while when step 503 is N, the equation (13) yields “Y = D
_OD + (M _NF / 2) + D _EF "521, and" S _B according to equation (14)
= (S _BD −Y) / L _PB “522 is calculated, S _B is calculated and stored in the RAM 66.

The storage status of each data in the RAM 66 is the same as in FIG.

Fig. 13 shows the flow chart during adjustment. When the TSW33 is turned on, the adjustment mode is entered. When the "Item setting" 601 for adjustment is performed as a code by the selection key of KB79, DP80
The "item display" 602 is made by the corresponding code on the item display section, and the "virtual value display" 603 corresponding by the number display section of the DP 80 is made by reading from the RAM 66.

Then, as shown in FIG. 8, "test plate making" 611 is performed, and as described above, the measured value corresponding to the assumed value displayed by step 603 is obtained, and in accordance with this, the "measured value input" 621 is input by the numeric keys of KB79. If this is done, the display of step 603 will be “updated to the actual measured value display” 623 assuming that Y of “assumed value = actual measured value?” 622. This “measured value is stored in RAM” 62
4 is performed, and steps 601 and subsequent steps are repeated through N of "TSW OFF?" 631.

In addition, adjustment of L _PS depends on the setting of the code "STP"
3060m / m, 0.1m / m step, STS32 position adjustment is 0-400m / m, 0.1m / m step, L
The adjustment of _PA and L _PB shall be performed according to the setting of codes “SDU” and “SDD”, respectively, within the range and accuracy of 189 to 199 m / m and 185 to 195 m / m, 1.0 m / m step. There is.

If the displayed assumed value and the measured value match,
Step 621 can be omitted.

In addition, STS32 position adjustment, the center value is 200m / m,
The positive and negative deviations are obtained from the measured values with reference to the center value, and the "+" and "-" keys are omitted from KB79.

In addition, since the assumed value is displayed, this is used as a standard for actual measurement.

Therefore, it is possible to easily correct the mechanical error,
No special correction value setting switch or the like is required, and simplification of the configuration and improvement of adjustment accuracy are realized.

Further, the regulation of the exposed portion with respect to the plate material 2 becomes accurate, and even if there is a dimensional deviation of the plate material 2, a document image can be reliably formed on a predetermined portion, and double exposure is performed easily and accurately, and , BD _A 19a, BD _B 19b prevent unwanted scattered light from entering, so that a plate with good contrast can be obtained.
Plate making speed is generally improved.

However, in the calculation of L _M, an error will occur if there is a dimensional deviation of the roller 14, so in this case the size of the roller 14 is made highly accurate and the occurrence of the error is prevented.
The dimensional deviation of 14 can be adjusted by the same means as described above.

As the MLS31 and STS32, other sensors other than photoelectric sensors may be used, and BD _A 19a and BD _B 19b are made to be a single sensor, and are moved around the exposure section 5 to stop at a predetermined position. The same applies to masking, and instead of the CPU 61, a dedicated combination of various logic circuits may be used, and PG ₁ 67, PG ₂ 68, CT ₁ 71 to CT ₅ 75 can be softened. It is also optional to configure.

It should be noted that, in FIGS. 8 to 13, various changes can be freely made, such as changing steps or omitting unnecessary steps depending on the situation.

[Effects of the Invention] As is apparent from the above description, according to the present invention, the image forming reference position can be arbitrarily set by measuring the length of the plate material, and the plate material with respect to the optical axis in the exposure unit can be set. The stop position of can be easily set to any position including the case where the center coincides with the optical axis. Also,
Since the stop position is controlled by controlling the drive amount of the step motor that feeds the plate material by the number of pulses, there are many effects such as the control with high dimensional accuracy while being a simple operation.

On the other hand, since the present invention can handle plate materials of various sizes, it is possible to easily form an image position corresponding to a printing machine from a small printing machine to a printing plate of a large printing machine.

Further, even if there is an actual dimension deviation of the plate material, the image is surely formed at the image forming reference position, so that it is not necessary to consider the deviation of the image position when mounting the printing plate on the printing machine. A remarkable effect can be obtained in various plate making machines.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a side sectional view of a plate making machine, FIG. 2 is a side view of essential parts, and FIGS. 3 to 6 are views showing an exposure relationship between an original and a plate material, FIG. 7 is a block diagram of the electrical configuration, and FIGS. 8 to 13 are flow charts showing control conditions. 2 ... Plate material, 2a ... Leading edge, 4 ... Charging part, 5 ... Exposure part, 6 ... Original plate, 7 ... Original, 8 ... Illumination lamp, 9 ...
Mirror, 10 ... Lens, 11 ... Developing section, 12 ... Fixing section,
14 …… roller, 15 …… optical axis, 17 …… belt, 18 …… chain, 19a …… BD _A (light blocking film), 19b …… BD _B (light blocking film),
20a, 20b …… Wire, 21a, 21b …… Winding shaft, 31 …… MLS
(Plate length sensor), 32 …… STS (stop sensor), 33 …… T
SW (switch), 41 ... SM ₁ (step motor), 42 ...
… 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 …… RA
M (memory), 67,68 …… PG ₁ , PG ₂ (pulse generator), 71
~ 75 …… CT ₁ ~ CT ₅ (counter), 79 …… KB (keyboard), 80 …… DP (display), 81 ~ 84 …… DR ₁ ~ DR ₄ (driver).

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Seiichi Honma 1-741 Kugayama, Suginami-ku, Tokyo Iwasaki Tsushinki Co., Ltd. (56) References JP-A-49-25948 (JP, A) JP-A-SHO 57-185426 (JP, A) JP 54-131403 (JP, A) JP 42-14090 (JP, B1) JP 56-13298 (JP, B2)

Claims (1)

[Claims] 1. A plate-making position control device of a plate-making machine, which feeds sheet-shaped plate materials one by one to an exposure section, and exposes a document image to the plate material in the exposure section. When sent to the exposure unit by a plate material length sensor for detecting the presence of a moving plate material, during the period when the plate material length sensor is detecting the presence of the plate material,
From the number of pulses supplied to the step motor that rotationally drives the roller, a plate material length measuring unit that measures the length L _M in the moving direction of the plate material, and a stop sensor provided at the position of the optical axis of the exposure unit. Based on the length L _M of the plate material, the transfer length Z _{1 of the} leading edge from the time when the front edge of the plate material passes the optical axis position until it stops is calculated, and this transfer length Z ₁ and the exposure unit A pulse number calculating means for calculating Z ₁ / L _PS to obtain a pulse number M ₁ from a length L _{PS at} which a step motor for feeding the plate material sends the plate material in one pulse, and the stop sensor is a plate material. And a drive control means for driving the step motor by the pulse number M ₁ calculated by the pulse number calculation means after detecting the leading edge of the plate-making position control device of the plate-making machine.