JP2003340578A - Method for laser marking - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent finishing from being decreased due to the change of a conveying speed when a dot-like marking pattern is formed while conveying an X-ray film. <P>SOLUTION: A laser marking apparatus inhibits writing of the marking pattern in the state that the line speed v of the X-ray film does not reach a predetermined speed vs, and eliminates the inhibiting of writing when the line speed becomes the speed vs or higher (steps 100 to 106). The apparatus is set to inhibit the stop of conveying the film when the marking is started, and eliminates the inhibiting of stopping when the writing of the marking pattern is finished (steps 108 to 114). Thus, when the line speed is extremely low, the writing of the marking pattern can be prevented, and hence the suitable marking pattern can be formed on the film. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention irradiates a printing medium such as a photosensitive material having an emulsion layer formed on the surface of a support with a laser beam so that it can be visually recognized at a predetermined position of the printing medium. The present invention relates to a laser marking method for forming a dot-shaped marking pattern of characters or symbols.

[0002]

2. Description of the Related Art Various marking techniques have been proposed in which a dot pattern such as characters and symbols is written on the surface of a material by using a laser beam (laser beam).

On the other hand, for example, Japanese Patent Application Laid-Open No. 5-238098 (hereinafter referred to as "prior art") proposes an apparatus for marking a preselected position on a continuously moving web. In this prior art, the amount of movement of the web is measured by a foot encoder such as a rotary encoder, and the printing means is controlled in synchronization with the movement of the web to mark the web at regular intervals. .

By the way, when the web wound around the core is pulled out from the outer peripheral edge and subjected to the marking process while being conveyed, when the web is completely pulled out from the core, the conveyance of the web is temporarily stopped. By connecting the leading end of the next web to the trailing end of this web, a plurality of webs are continuously marked. Further, when marking the web and cutting the web at a predetermined interval to obtain a sheet-shaped photosensitive material or the like, when the web is cut, the conveyance of the web is temporarily stopped.

[0005]

However, the rotary encoder outputs pulse signals at intervals according to the moving speed of the web, and when dots are formed on the web based on this pulse signal for marking, the web encoder If the moving speed becomes extremely slow, the intervals of the pulses output from the rotary encoder become long, and the irradiation timing of the laser beam may shift. Further, when the web is stopped, back tension may cause a return.

For this reason, if the web is marked while the web is conveyed / stopped repeatedly, the dot spacing may change, and the characters may be deformed or overprinted.

The present invention has been made in view of the above facts. When marking a long print object such as a web, the occurrence of print defects due to changes in the moving speed such as the stop of the print object occurs. It is an object of the present invention to provide a laser marking method for preventing.

[0008]

In order to achieve the above object, the present invention is a laser marking method for forming a dot-shaped marking pattern by irradiating a printing medium moving in a predetermined direction with a laser beam. The moving speed of the printing object is detected, and the marking pattern is formed by irradiating the printing object with the laser beam when the moving speed exceeds a predetermined speed.

According to the present invention, when a dot-shaped marking pattern is formed by irradiating a laser beam while the object to be printed is conveyed, when the speed of conveyance of the object to be printed is equal to or higher than a predetermined speed, Irradiate the printed material with a laser beam.

At this time, the predetermined speed is set to the minimum speed at which the intervals and shapes of the dots forming the marking pattern are properly maintained, so that the occurrence of printing defects can be reliably prevented and the imprinted mark can be prevented. An appropriate marking pattern can be formed on the font.

According to a second aspect of the present invention, when the moving speed of the object to be printed is less than the predetermined speed, the start of irradiation of the laser beam to the object to be printed is prohibited.

According to the present invention, when the print speed of the print medium is less than the predetermined speed, the irradiation of the laser beam to the print medium is prohibited, and the print speed of the print medium exceeds the predetermined speed. Sometimes, a laser beam is irradiated to form a marking pattern.

With this configuration, it is possible to surely prevent the laser beam from being emitted and causing the dot interval deviation, the over-printing, or the like to occur when the conveyance speed of the printing object is less than the predetermined speed. it can.

The invention according to claim 3 is characterized in that the moving speed of the printing object is maintained at the predetermined speed or more while the marking pattern is being formed on the printing object.

According to the present invention, while the marking material is being irradiated with the laser beam to form the marking pattern, the conveyance speed of the printing material is maintained at a predetermined speed or higher.

Thus, when the marking pattern is formed, it is possible to surely prevent the conveyance speed of the printing object from being lowered, resulting in the partial deviation of the dot interval and the overlapping ejection. A proper marking pattern can be formed.

In the present invention as described above, when the amount of movement of the object to be printed in the predetermined direction is detected and the marking pattern is formed on the object to be printed at predetermined intervals in the moving direction, the marking pattern is formed. It is preferable to accumulate the movement amount when the printing target moves in the direction opposite to the predetermined direction and subtract the accumulated amount from the movement amount of the printing target in the predetermined direction. It is possible to prevent the deviation of the dot interval, the overlapping printing of dots and the like due to the large return of the printing medium when the conveyance of is stopped.

The marking device for accomplishing the present invention is provided with a conveying means for conveying the printing object along a predetermined conveying path and a predetermined position of the conveying path so as to face each other at a predetermined timing. A marking head for forming a dot-shaped marking pattern on the printing object by irradiating the printing object while being scanned along the transportation path with the laser beam, and a transportation speed of the printing object. When the conveyance speed of the printing object detected by the speed detection means and the speed detection means is a predetermined speed or more, it is possible to irradiate the laser beam from the marking head to the printing object. Marking control means for performing the above.

Further, in the marking device to which the present invention is applied, the marking control means controls the marking head from the marking head when the conveyance speed of the object to be printed detected by the speed detecting means is less than a predetermined speed. It is preferable to prohibit the irradiation of a laser beam, and the judgment means includes a judgment means for judging whether or not a marking pattern is being formed by irradiating the object to be printed with the laser beam from the marking head. It is preferable that, when it is determined that the marking pattern is being formed, the marking control means controls the carrying means so as to maintain the carrying speed of the object to be printed at a predetermined speed or more.

Further, as a marking device to which the present invention is applied, a movement amount detecting means for detecting a movement amount when the print object is conveyed along the forward direction, and a forward direction of the print object. And a means for accumulating the amount of movement in the opposite direction when a movement along the opposite direction is detected, the marking control means detecting the movement amount detecting means by the movement amount detecting means. When the marking head is actuated based on the moving amount, the amount of movement of the printing target in the forward direction is subtracted from the amount of movement of the printing target stored in the storage unit in the reverse direction. It is preferable to calculate.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a schematic configuration of a marking device 10 applied to this embodiment. The marking device 10 irradiates the surface of the X-ray film 12 with a laser beam LB in the process of conveying the X-ray film 12 with the long X-ray film 12 wound into a roll as a printing medium. As a result, a marking pattern such as characters and symbols is formed (marking process).

As shown in FIG. 2, the X-ray film 12
Is a base layer 14 formed using PET (polyethylene terephthalate) as a support, and the base layer 1
4 and the emulsion layer 16 formed on at least one surface of the photographic material 4.

As shown in FIG. 1, the X-ray film 12
Is wound around the core 18 in a roll shape with the emulsion layer 16 facing inward, and the core 18 is axially supported and mounted on the pedestal 20. X ray film 12 mounted on the pedestal 20
Is drawn from the outermost layer below the winding core 18.

On the other hand, in the marking device 10, pass rolls 22 and 24 are vertically arranged adjacent to the base 20. The X-ray film 12 drawn out from the outermost layer is wound around the pass roll 22 and directed upward, and further wound around the pass roll 24 so as to be directed substantially horizontally.

Small rolls 26 and 28 are arranged in pairs on the downstream side of the pass rolls 24 in the conveying direction (the direction of the arrow in FIG. 1).
A main feed roll 30 is arranged between the small rolls 26 and 28. The X-ray film 12 is adapted to be wound around the main feed roll 30 between the small rolls 26 and 28.
A substantially U-shaped transport path is formed between the portions 6 and 28.

A print roll 32 is arranged on the downstream side of the small roll 28, and small rolls 34 and 36 are arranged below the print roll 32 in pairs. When it is wound around and is directed downward, it is directed substantially horizontally between the small rolls 34 and 36.

The main feed roll 30 has a large number of small holes (not shown) formed on the outer peripheral surface thereof, and the X-ray film 12 wound around the outer peripheral surface is formed by a negative pressure supplied from a negative pressure source (not shown). It is a suction roll that holds by suction. Also, the main feed roll 30 is
It is adapted to be rotationally driven by the driving force of a driving means (not shown).

As a result, the X-ray film 12 is wound around the main feed roll 30 so that the X-ray film 12 is conveyed at a moving speed (hereinafter referred to as "line speed v") corresponding to the number of revolutions of the main feed roll 30 and printed. It is sent out to the roll 32 and wound around the print roll 32. The X-ray film 12 is horizontally conveyed between the small rolls 34 and 36 by being directed substantially downward from the print roll 32 and wound around the small rolls 34 and 36.

A sub-feed roll 38 and a backup roll 40 are arranged in a pair above the small roll 36. The X-ray film 12 is fed from the small roll 36 substantially vertically and wound around the sub-feed roll 38. Can be hung.

The sub-feed roll 38 is rotated by the driving force of a drive source (not shown), holds the X-ray film 12 with the backup roll 40, and sends it out in a substantially horizontal direction.

Further, on the downstream side of the sub feed roll 38, pass rolls 42 and 44 and a reversing roll 46 are arranged, and the X fed from the sub feed roll 38 is sent.
The lay film 12 is directed upward by being wound around the pass roll 42, and further, is wound substantially horizontally toward the reversing roll 46 by being wound around the pass roll 44.

Below the reversing roll 46, winding cores 48 and 50 for winding the X-ray film 12 are arranged. The X-ray film 12 is wound around the reversing roll 46 and directed toward the winding core 48 or the winding core 50.

On the other hand, in the marking device 10, slit blades 52 and 54 are provided in a pair between the small rolls 34 and 36 in the vertical direction. The slit blades 52, 54 rotate while being driven by the driving force of a driving source (not shown), and the small roll 3
The X-ray film 12, which is conveyed substantially horizontally, is sandwiched between Nos. 4 and 36. As a result, the X-ray film 12 is cut by the slit blades 52 and 54 at a predetermined position along the width direction (for example, an intermediate position in the width direction), and is wrapped around the small roll 36 as the two-row X-ray film 12. It is conveyed toward the reversing roll 46.

Slit blades 52, 5 are provided on the winding cores 48, 50.
The X-ray film 12 cut along the longitudinal direction by 4 is wound around each. As a result, the X-ray film 12 is wound around each of the winding cores 48 and 50 in a roll shape by rotating and driving each of the winding cores 48 and 50. In addition, a plurality of pairs of slit blades 52, 5
4 may be provided, whereby it is possible to divide the X-ray film 12 (narrow width web) having a narrow width of three or more lines.

On the other hand, a marking head 56 is provided near the print roll 32. The marking head 56 includes a laser oscillator 58 and a beam deflector 60, and irradiates the X-ray film 12 wound around the print roll 32 with the laser beam LB.

The laser oscillator 58 applied to this embodiment is a CO ₂ laser and emits a laser beam LB having a constant wavelength in a predetermined time width based on an input drive signal.

The beam deflector 60 is provided with, for example, an AOD (acoustic optical device), and when a deflection signal is input, the laser beam LB is generated based on this deflection signal.
Are scanned along the width direction of the X-ray film 12. The scanned laser beam LB is imaged on the X-ray film 12 by an optical system (not shown) such as a condenser lens so as to form a focus of a predetermined spot diameter.

The marking device 10 also includes a laser controller 62, a winding controller 64, and a marking controller 66.
Is equipped with.

A pattern signal corresponding to a marking pattern such as characters or symbols to be recorded on the X-ray film 12 is input to the laser controller 62. The pattern signal is sent to the winding control unit 64 or the marking control unit 6
6 may be input at a predetermined timing, or may be stored in the laser control unit 62 in advance.

The laser control unit 62 outputs a drive signal to the laser oscillator 58 based on the pattern signal so that the laser beam LB is emitted from the laser oscillator 58 and a deflection signal is output to the beam deflector 60 to output the laser beam. Scan LB. That is, the laser control unit 62 sets the moving direction of the X-ray film 12 as the main scanning direction and the width direction of the X-ray film 12 as the sub-scanning direction.
Irradiate the laser beam LB.

The X-ray film 12 has a laser beam L
The irradiation of B melts the emulsion layer 16 to form convex dots on the emulsion layer 16. As a result, for example, as shown in FIGS. 3 and 4, a predetermined marking pattern MP is formed on the X-ray film 12 in a predetermined dot pattern. 3 and 4, a plurality of alphabets are formed by 5 × 5 dots as an example of the marking pattern MP.

On the other hand, the X-ray film 12 has the emulsion layer 16
A plurality of fine bubbles are generated in the expanded inside of the dot in the process of melting by the thermal energy of the laser beam LB. In this embodiment, the convex amount of dots formed on the emulsion layer 16 at this time is 10 μm or less, and the size (diameter) of each bubble is 1 to 5 μm.

In the X-ray film 12, since a plurality of fine bubbles are formed in the emulsion layer 16, a large number of boundary films are formed between the bubbles, and diffuse reflection of light is promoted. As a result, in the present embodiment, the amount of reflected light greatly changes inside and outside the dots, so that the dots can be visually recognized regardless of whether the X-ray film 12 is undeveloped or developed, or the density of the dots. At the same time, the visibility of the dots is improved.

The irradiation time of the laser beam LB for forming such dots is such that the oscillation wavelength of the laser oscillator 58 (wavelength of the laser beam LB) is in the 9 μ band (for example, wavelengths such as 9.3 μm and 9.6 μm). 1 μsec to 15 μs
It is in the range of ec. When the oscillation wavelength of the laser oscillator 58 is in the 10 μm band (for example, 10.6 μm), the irradiation time of the laser beam LB is 5 μsec to 18 μsec.
By doing so, it is possible to form the dots described above, but in the present embodiment, in order to improve the work efficiency, the laser oscillator 58 that oscillates the laser beam LB of 9 μm band wavelength is applied. There is.

Further, it is preferable to further control the irradiation time of the laser beam LB so that no space is formed at the boundary surface between the base layer 14 and the emulsion layer 16 of the X-ray film 12. This space is different from the bubble generated in the emulsion layer 16 when forming dots, and when this space is formed between the base layer 14 and the emulsion layer 16, the laser beam LB is irradiated. Although the visibility of the dots becomes high at the time of forming the dots by using the X-ray film 12, the emulsion layer 16 on the upper side of this space is scattered and opened by performing the developing process on the X-ray film 12. The above irradiation time (15 μsec in 9 μm band, 1 in 10 μm band)
The same state as when dots are formed for more than 8 μsec.

That is, in order to prevent a space from being formed between the base layer 14 and the emulsion layer 16 of the X-ray film 12, the irradiation time of the laser beam LB is set to 9 times the oscillation wavelength.
1 μsec to 10 μsec in μm band, 5 μsec to 8 in 10 μm band
By controlling in a narrow range of μsec, it is possible to reduce the difference between the visibility evaluation at the manufacturing stage of the X-ray film 12 and the visibility evaluation by the user.

The irradiation time of the laser beam LB at this time is almost the same between the 9 μm band and the 10 μm band (10.6 μm), but the dots formed by the laser beam LB having the wavelength band of 10 μm are convex. Since the amount is about twice the convex amount of the dot formed by the laser beam LB having a wavelength of 9 μm band, it is preferable to use the laser beam LB having a wavelength of 9 μm band from the viewpoint of dot visibility. In the embodiment, the laser oscillator 58 that generates the laser beam LB having a wavelength of 9 μm band is used.

On the other hand, in the marking device 10, the marking patterns MP are formed on both sides of the cut line 68 (shown by a chain double-dashed line in FIGS. 3 and 4) when the X-ray film 12 is cut by the slit blades 52 and 54. To form.

As a result, the marking pattern MP is formed on each of the X-ray films 12 wound around the winding cores 48 and 50 at one end in the width direction.
In the marking device 10, the marking pattern MP is formed on both sides with the cut line 68 sandwiched therebetween, but the marking pattern MP is not limited to this, but the marking pattern MP is formed in an arbitrary direction and position. It may be

The winding control section 64 includes a main feed roll 30, a sub-feed roll 38, winding shafts 48, 5
A drive source (not shown) for driving each of the 0 and the slit blades 52, 54 is connected. As a result, the winding control unit 64 conveys the X-ray film 12 from the winding core 18 at a predetermined conveyance speed (hereinafter referred to as “line speed v”) while pulling it out and cuts it in the longitudinal direction by the slit blades 52 and 54. After that, each is wound around the winding cores 48 and 50 in a roll shape.

Further, the web tension pickup 7 is attached to the pass roll 24, the small roll 36 and the pass roll 44.
0 is provided. These web tension pickups 70 are connected to a winding control section 64 (not shown), and the winding control section 64 makes the tension of the X-ray film 12 detected by the web tension pickups 70 substantially constant. In addition, while controlling the winding speed of the main feed roll 30 and the sub-feed roll 38 and the winding cores 48 and 50 to prevent the X-ray film 12 from being loosened or having an unnecessarily large tension,
Conveyance and winding on the winding cores 48 and 50 are performed.

The marking device 10 also includes a web edge control sensor 7 between the pass rolls 22 and 24.
Two are provided. The marking device 10 detects the position in the width direction of the X-ray film 12 sent from the original fabric by the web edge control sensor 72, and controls the position of the winding core 18 of the original fabric, thereby the end portion in the width direction. The X-ray film 12 is conveyed so that is at a fixed position.

Further, the winding control section 64 detects the rotation speed of the winding core 18 by a sensor (not shown) and calculates the winding diameter from the rotation speed of the winding core 18 and the line speed v, whereby the X-ray film 12 The remaining amount and the presence / absence are judged, and when it is judged that the X-ray film 12 is exhausted, the X-ray film 12 is decelerated and stopped. As a result, by connecting the rear end of the X-ray film 12 to the front end of the next X-ray film 12, a plurality of original X-ray films 1 can be obtained.
The marking process can be continuously performed on the second item.

In the winding control section 64, the winding core 48,
A predetermined amount of X-ray film 12 (for example, X-ray film 1 wound around one winding core 18)
2) when it is wound up, or when the rear end of the X-ray film 12 reaches the vicinity of the winding cores 48, 50.
The conveyance of the lay film 12 is stopped. As a result, the cores 48 and 50 are replaced so that the X-ray film 12 can be wound onto the new cores 48 and 50.
That is, the marking device 10 carries out the marking process on the X-ray film 12 while carrying / stopping the X-ray film 12 at a predetermined timing.

By the way, in the marking device 10, a rotary encoder 74 is attached to the print roll 32. This rotary encoder 74
The print roll 32 rotates together with a rotation shaft (not shown) of the print roll 32, converts the rotation angle of the print roll 32 into a pulse signal, and outputs the pulse signal to the marking control unit 66.

At this time, as shown in FIG. 5 (A), the rotary encoder 74 outputs two pulse signals (pulse signal A and pulse signal B shown in FIG. 5 (A)) whose phases are shifted by 1/4 cycle. It has a general configuration for outputting.

As shown on the right side of the paper of FIGS. 5A and 5B, the rotary encoder 74 has a forward direction (see FIG. 1) in which the X-ray film 12 moves from the core 18 to the cores 48 and 50. When the print roll 32 is rotated in the forward direction so as to move in the direction of the arrow), the pulse signal B, for example, of the pulse signals A and B output from the rotary encoder 74 precedes the pulse signal A.

The rotary encoder 74 has an X
When the lay film 12 moves in the opposite direction (the direction opposite to the arrow in FIG. 1) and the print roll 32 rotates in the reverse direction,
As shown on the left side of the paper of FIG. 5B, the output pulse signal has a reverse phase and the pulse signal A advances with respect to the pulse signal B.

As a result, the marking controller 66 can measure the amount of movement of the X-ray film 12 from the pulse signal (RE output) output from the rotary encoder 74. When counting the amount of movement of the X-ray film 12, either one of the pulse signals may be used, or a composite signal (for example, OR output) may be used. In the following, it will be simply referred to as a pulse signal (RE output). explain.

The marking control unit 66 counts or accumulates the pulse signals output from the rotary encoder 74 according to the amount of movement of the X-ray film 12, and sends to the laser control unit 62 each time the count value reaches a predetermined value. A write signal is output (see FIGS. 6A and 6B). That is, the marking controller 66 measures the amount of movement of the X-ray film 12 and outputs a write signal to the laser controller 62 each time the amount of movement reaches a predetermined amount.

When the write signal is input, the laser control unit 62 outputs a drive signal to the laser oscillator 58 and a deflection signal to the beam deflector 60 in accordance with the pattern signal of the marking pattern. At this time,
In the laser control unit 62, the rotary encoder 74
The laser beam LB is emitted in synchronization with the pulse signal output from the X ray film 12 to form a predetermined marking pattern MP.

Further, in the marking controller 66, from the pulse signal input from the rotary encoder 74,
The line velocity v is detected along with the moving direction of the X-ray film 12. The line speed v at this time can be obtained from the number of pulses input from the rotary encoder 74 per unit time.

The marking control unit 66 calculates the line speed v of the X-ray film 12, and when the line speed v becomes lower than a predetermined speed vs set in advance, the carry amount of the X-ray film 12 becomes a predetermined amount. Even if it has reached, the output of the write signal to the laser control unit 62 is stopped. That is, in the marking control unit 66, the line speed v of the X-ray film 12 is less than the predetermined speed vs (v <
If it is vs), writing of the parking pattern MP is prohibited.

In the marking control unit 66, the number of characters of the marking pattern MP, the number of dots per character,
X from one marking pattern MP from line speed v
The time (marking time) required to form on the lay film 12 is calculated. When the marking control unit 66 outputs a write signal to the laser control unit 62, it outputs a stop prohibition signal to the winding control unit 64 so as to prohibit the conveyance stop of the X-ray film 12 during this marking time.

As described above, the winding control section 64 stops the conveyance of the X-ray film 12 at a predetermined timing (line speed v = 0), but when the marking control section 66 inputs a stop prohibition signal. , The X-ray film 1 is stopped until the stop prohibition is released (the stop prohibition signal is turned off) even when the timing for stopping the conveyance of the X-ray film 12 is reached.
Continue to carry 2. At this time, the winding control unit 64 maintains at least the line speed v so as not to drop below the predetermined speed vs.

That is, as shown in FIGS. 6A and 6B, in the marking control unit 66, when the X-ray film 12 is being conveyed at a line speed v higher than the speed vs, the X-ray film 12 is conveyed. A write signal is output (turned on) each time the carry amount of (1) reaches a predetermined amount. This allows
While the X-ray film 12 is being marked, the conveyance stop is prohibited (stop prohibition is ON).

Further, as shown in FIG. 6B, the take-up control section 64 comes to the timing of stopping the X-ray film 12 and when the stop signal is turned on, the X-ray film 12 is turned on.
Stop the transportation of. When stopping the transportation, X
The line speed v of the ray film 12 is gradually decreased.

At this time, the marking control unit 66 prohibits writing (writing inhibition is turned on) when the line speed v of the X-ray film 12 becomes lower than the speed vs.

In the present embodiment, this predetermined speed vs.
Is set to the minimum line speed v at which the gap between dots formed on the X-ray film 12 does not occur using the laser beam LB emitted from the marking head 56. The marking process for forming the marking pattern MP is performed only when the marking pattern MP is conveyed at a line speed v equal to or higher than vs.

On the other hand, the marking controller 66 is provided with a memory 76 as a storage means. When the marking controller 66 detects the reverse rotation of the rotary encoder 74 from the pulse signal output from the rotary encoder 74, it stores the reverse rotation amount in the memory 76.

In the marking device 10, when the X-ray film 12 is conveyed in the forward direction and the conveyance of the X-ray film 12 is stopped, for example, it is interposed between the motor serving as a drive source and the main feed roll 30. The X-ray film 12 may be pulled back to the winding core 18 side and moved in the opposite direction due to backlash of the gears and back tension applied to the X-ray film 12.

When the marking controller 66 detects the movement of the X-ray film 12 in the opposite direction, the marking controller 66 counts the number of pulses, which is the amount of movement of the X-ray film 12, as shown in FIG. Accumulate in 76 (Fig. 5B
(B) Left side of the page). That is, the marking control unit 66
Then, the amount of movement of the X-ray film 12 in the reverse direction is stored in the memory 76.

Further, in the marking control unit 66, when the X-ray film 12 moves in the forward direction, the forward movement amount is subtracted from the backward movement amount stored (stored) in the memory 76 ( After the drawing is performed on the right side of the paper surface of FIG. 5B, the addition of the movement amount in the forward direction is started.

That is, in the marking control unit 66, X
When the ray film 12 moves in the reverse direction, the amount of movement of the X ray film 12 in the reverse direction is accumulated, and when the X ray film 12 moves in the forward direction, the accumulated movement amount is subtracted. There is.

As a result, in the marking control unit 66,
Even when the X ray film 12 is returned due to backlash or the like when the transport of the X ray film 12 is stopped, the proper movement amount of the X ray film 12 can be counted.

The operation of this embodiment will be described below.

In the marking device 10, the X-ray film 12 is wound around the pedestal 20 in a roll shape.
Is mounted, the main feed roll 30, the sub feed roll 38, and the winding cores 48, 50 are rotatably driven to
The lay film 12 is conveyed in the forward direction at a predetermined line speed v. As a result, the X-ray film 12 is wound around the main feed roll 30 and then sent out from the main feed roll 30 toward the print roll 32.

At this time, the winding control section 64 controls the rotations of the main feed roll 30, the sub feed roll 38, and the winding cores 48, 50 so that the tension of the X-ray film 12 becomes substantially constant. When the X-ray film 12 is wound around the main feed roll 30, the X-ray film 12 is attracted to the peripheral surface of the main feed roll 30,
It is reliably sent out to the print roll 32 without slippage or the like, and wound around the winding cores 48, 50 without loosening or the like.

Further, in the marking device 10, the slit blades 52 and 54 are rotationally driven to cut the X-ray film 12 at the middle portion in the width direction, so that the winding cores 48 and 50 are formed.
The X-ray film 12 cut into each of the above is wound.

By the way, the marking apparatus 10 is provided with a marking head 56 facing the print roll 32, and by irradiating the X ray film 12 wound around the print roll 32 with the laser beam LB, A predetermined marking pattern MP is formed on the lay film 12.

At this time, in the marking device 10, the marking control section 66 controls the conveyance of the X-ray film 12 while performing the marking process for writing the marking pattern MP on the X-ray film 12.

Here, referring to FIGS. 7 to 10,
The outline of the conveyance control of the X-ray film 12 and the marking process will be described. The flow charts shown in FIGS. 7 and 8 are executed in parallel with the conveyance of the X-ray film 12.

FIG. 7 shows the outline of the transport control for performing the marking process on the X-ray film 12. In this flowchart, when the transport process of the X-ray film 12 is started, first, in step 100, writing is prohibited (marking is prohibited).

Thereafter, the line speed v of the X-ray film 12 is calculated from the pulse signal input from the rotary encoder 74, and in step 102, it is confirmed whether or not the line speed v exceeds the speed vs. As a result, when the line speed v of the X-ray film 12 exceeds the speed vs (v ≧ vs), an affirmative decision is made in step 102, the process proceeds to step 104, and the write protection is released.

In step 106, it is checked whether the line speed v of the X-ray film 12 is lower than the speed vs. If the line speed v is lower than the speed vs (v <vs), the step 106 is executed. If an affirmative decision is made, the operation proceeds to step 100, and writing is prohibited. That is,
When the line speed v is equal to or higher than the speed vs (v ≧ vs), the write protection of the marking pattern MP is released.

FIG. 8 shows an outline of writing (marking processing) control of the marking pattern MP. In addition,
In the following, when the movement amount L of the X-ray film 12 (or the number of pulses corresponding to this movement amount) reaches a predetermined value Ls, X
The description will be made assuming that the marking pattern MP is formed on the lay film 12.

This flowchart is for X ray film 1
The first step 12 is executed when the second transfer is started.
At 0, it is confirmed whether or not the transport direction of the X-ray film 12 is the forward direction. If the X-ray film 12 is transported in the forward direction, an affirmative decision is made in step 120 and step 1
Then, the process proceeds to step 22, and it is confirmed whether or not the amount of movement in the reverse direction is accumulated.

As a result, when the amount of movement of the X-ray film 12 in the reverse direction is not accumulated, step 12
An affirmative decision is made in step 2 and the routine proceeds to step 124 where the amount of movement L of the X-ray film 12 is integrated by counting the pulses output from the rotary encoder 74.

Further, in step 126, it is confirmed whether or not the movement amount L of the X-ray film 12 has reached a preset predetermined value Ls.

Here, when the movement amount L of the X-ray film 12 reaches the predetermined value Ls, an affirmative decision is made in step 126, and the marking pattern MP writing process (marking process) is performed.

In the writing process of the marking pattern MP, first, in step 128, it is confirmed whether or not the writing is prohibited, that is, whether the line speed v is equal to or higher than the speed vs, and the writing is prohibited. If not (Yes at Step 128), Step 13
After shifting to 0, a write signal is output to the laser control unit 62.

As a result, the laser controller 62 outputs a drive signal and a deflection signal to the marking head 56 in accordance with the pattern signal of the marking pattern, and irradiates the X-ray film 12 with the laser beam LB. As a result, the marking pattern MP corresponding to the pattern signal is formed on the X-ray film 12.

At the same time, in step 132, the movement amount L of the X-ray film 12 is reset, and integration of the movement amount L is newly started.

In this way, the marking pattern is written every time the movement amount L of the X-ray film 12 reaches the predetermined value Ls, whereby the X-ray film 12 is
The marking patterns MP are formed at intervals according to the predetermined value Ls.

On the other hand, in the flowchart shown in FIG. 7, in step 108, it is confirmed whether or not the marking process is started, that is, whether or not the writing signal is output to the laser control unit 62.

Here, when the write signal is output to the laser control unit 62, an affirmative decision is made in step 108 and the operation proceeds to step 110 to prohibit the conveyance of the X-ray film 12 from being stopped. After this, the predetermined marking time has passed,
When the irradiation of the laser beam LB onto the X-ray film 12 is completed, an affirmative decision is made in step 112, and step 1
Then, the process proceeds to step 14, and the stop of the conveyance of the X-ray film 12 is released.

As described above, in the marking device 10, the X
Only when the line speed v when the lay film 12 is conveyed is equal to or higher than a predetermined speed vs, the marking pattern M
P is set to be writable, and when the marking pattern MP is formed, the line speed v is prevented from falling at least below the speed vs.

For example, as shown in FIG. 9, when the stop signal is turned on, the winding control section 64 stops the conveyance of the X-ray film 12. At this time, when the line speed v of the X-ray film 12 becomes lower than the speed vs, the marking control unit 66 sets the write-protection (write-protection ON).

As a result, as shown by the chain double-dashed line, the writing process of the marking pattern (marking process) to the X-ray film 12 is performed even at the timing of forming the marking pattern MP on the X-ray film 12. There is no.

When the conveyance of the X-ray film 12 is restarted and the line speed v of the X-ray film 12 exceeds the speed vs, the write-inhibition is released and the write signal is output, and the marking pattern MP is printed on the X-ray film 12. The marking process is performed.

On the other hand, as shown in FIG. 10, when the stop signal is input, the winding control section 64 lowers the line speed v in order to stop the conveyance of the X-ray film 12.

At this time, before the line speed v reaches the speed vs, the marking controller 66 changes the laser controller 62 to the laser controller 62.
Write signal is output to the X-ray film 12
When it is set to prohibit the conveyance stop of the X-ray film 12, the winding control unit 64 changes the line speed v of the X-ray film 12 to the speed v.
After the writing processing of the marking pattern MP to the X-ray film 12 is completed and the stop inhibition is released (write inhibition is turned off), the X-ray film 12 is maintained.
Slow down to stop.

Although FIG. 10 shows an example in which the writing of the marking pattern MP is started in the middle of deceleration for stopping the conveyance of the X-ray film 12,
The same applies when a signal for stopping the conveyance is input during marking.

As described above, in the marking device 10, the X
When the line speed v of the ray film 12 is equal to or higher than a predetermined speed vs, the marking process is performed, and the line speed v is the predetermined speed v during the marking process.
Since it is maintained so as to be s or more, it is possible to form appropriate marking patterns MP on the X-ray film 12 at substantially predetermined intervals.

That is, when the marking pattern MP is represented by an array of dots (dot pattern), it is necessary to make the diameters of the individual dots substantially constant in order to form a high-quality marking pattern MP. Of course,
X-ray film 1
If the line speed v of 2 is extremely low, the shape of the dots will change, and the spacing between the dots will change.

On the other hand, in the marking device 10,
When the line speed v becomes lower than the preset speed vs, the writing of the marking pattern MP is suspended, and when the line speed v exceeds the speed vs, the writing of the marking pattern MP is started. Also, the marking device 1
When 0 is writing the marking pattern MP on the X-ray film 12, the X-ray film 12 is prohibited from being stopped and the line speed v is maintained at a predetermined speed vs or higher.

As a result, in the marking device 10, it is possible to surely prevent the dot quality or the like from being generated in the marking pattern MP due to the line speed v and deteriorating the finish quality.

On the other hand, at least when the X-ray film 12 is not being conveyed in the forward direction due to, for example, the conveyance of the X-ray film 12 being stopped, a negative determination is made in step 120 of the flowchart of FIG. To do. In this step 134, it is confirmed whether or not the X-ray film 12 is moving in the opposite direction.

If the X-ray film 12 moves in the reverse direction when the X-ray film 12 is stopped to be conveyed, an affirmative decision is made in step 134, and the operation proceeds to step 136 to reverse the X-ray film 12 in reverse. The amount of movement in the direction is stored in the memory 76.

After that, when the forward movement of the X-ray film 12 is started, an affirmative decision is made in step 122, the process proceeds to step 138, and the movement amount of the X-ray film 12 stored in the memory 76 is moved. X ray film 12
Is subtracted from the amount of movement in the forward direction of the memory 76, and when there is no amount of movement in the reverse direction in the memory 76, an affirmative decision is made in step 122, the process proceeds to step 124, and the X-ray film 1
The counting of the movement amount of 2 is restarted.

That is, when the transportation of the X-ray film 12 is stopped, the X-ray film 12 may be pulled back toward the winding core 18 due to backlash or the like. At this time, in the marking device 10, the movement amount of the X-ray film 12 in the reverse direction is accumulated, and when the X-ray film 12 is moved in the forward direction, the accumulated movement amount in the reverse direction is subtracted. I have to.

As a result, in the marking device 10, the X
Even when the X-ray film 12 is largely pulled back in the opposite direction when the transportation of the ray film 12 is stopped, it is possible to reliably prevent the spacing of the marking patterns MP formed on the X-ray film 12 from being narrowed. .

In this embodiment, a plurality of characters and symbols are formed as one marking pattern MP. However, each of the plurality of characters and symbols is formed as a marking pattern MP and a plurality of marking patterns are formed. One marking pattern may be formed by forming the marking patterns at narrow intervals.

In such a case, the X-ray film 12 is returned in the opposite direction when the marking pattern formed before the stop and the next marking pattern subsequent to the marking pattern are formed after the stop. , Dots of different characters may get too close or overlap.

On the other hand, in the marking device 10,
The amount of movement when the X-ray film 12 moves in the reverse direction is accumulated in the memory 76, and when the X-ray film 12 moves in the forward direction, the amount of movement in the reverse direction accumulated in the memory 76 is subtracted. As a result, even when a plurality of characters or symbols are formed in order, it is possible to reliably prevent the spaces between the characters or symbols from being clogged, dot overprinting, etc. Can be formed.

The above-described embodiment shows an example of the present invention and does not limit the configuration of the present invention. For example, in the present embodiment, the amount of movement of the X-ray film 12 in the reverse direction is stored in the memory 76, but the present invention is not limited to this, and the amount of movement of the X-ray film 12 in the forward direction is stored in the memory 76. Alternatively, the amount of movement in the reverse direction may be subtracted from the amount of movement in the forward direction stored in the memory 76.

In the present embodiment, the X-ray film 12 which is a kind of photographic light-sensitive material as an object to be printed is taken as an example, and the X-ray film 12 is cut into two lines to mark each X-ray film. Although the description has been made using the marking device 10 that forms the pattern MP, the present invention is not limited to X.
The present invention can be applied not only to the lay film 12 but also to marking of any photographic light-sensitive material, and also to a marking device for forming a dot-shaped marking pattern by a laser beam on any object to be printed not limited to photographic light-sensitive material. can do.

[0119]

As described above, according to the present invention, the marking pattern is formed on the printing medium only when the printing medium is conveyed at a predetermined speed or higher. The excellent effect that a proper marking pattern can be formed on the printing medium is obtained.

Further, according to the present invention, it is possible to reliably prevent the marking pattern from being defective due to the conveyance speed of the printing object.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a marking device applied to the present embodiment.

FIG. 2 is a schematic configuration diagram of an X-ray film used as an object to be printed in the present embodiment.

FIG. 3 is a schematic perspective view of a main portion in the vicinity of a print roll showing a formation state of a marking pattern with a dot pattern.

FIG. 4 is a schematic plan view of a main part of an X-ray film on which a marking pattern is formed.

FIG. 5A is a diagram showing an outline of a pulse signal output from a rotary encoder, and FIG. 5B shows an outline of a pulse signal according to a rotation direction of the rotary encoder and a change in a movement amount accumulated in a memory. It is a diagram showing.

FIG. 6A is a diagram schematically showing a pulse output according to a line speed and a stop prohibition signal according to a write signal;
(B) is a diagram schematically showing changes in line speed and pulse output according to a stop signal and write inhibition.

FIG. 7 is a flow chart showing an example of transport control for performing writing processing of a marking pattern.

FIG. 8 is a flowchart showing an outline of writing control of a marking pattern based on a line speed and a moving amount of an X-ray film.

FIG. 9 is a diagram showing an example of timings of a change in line speed according to a stop signal, pulse output, write inhibition, and writing processing of a marking pattern.

FIG. 10 is a diagram showing another example of the timing of line speed change, pulse output, write prohibition, and marking pattern write processing in response to a stop signal.

[Explanation of symbols]

10 Marking device 12 X ray film (printed material) 30 main feed rolls 32 print rolls 56 marking head 62 Laser controller 64 Winding control section 66 Marking controller 74 rotary encoder 76 memory (storage means) LB laser beam MP marking pattern

Claims (4)

[Claims] 1. A laser marking method for forming a dot-shaped marking pattern by irradiating a printing object moving in a predetermined direction with a laser beam, the moving speed being detected by detecting the moving speed of the printing object. The laser marking method is characterized in that the marking pattern is formed by irradiating the object to be printed with the laser beam when the speed exceeds a predetermined speed. 2. The laser marking according to claim 1, wherein when the moving speed of the printing medium is less than the predetermined speed, the start of irradiation of the laser beam to the printing medium is prohibited. Method. 3. The moving speed of the printing object is maintained at the predetermined speed or more while the marking pattern is being formed on the printing object. Laser marking method. 4. When the amount of movement of the object to be printed along a predetermined direction is detected and the marking patterns are formed on the object to be printed at predetermined intervals along the moving direction, the object to be printed is 4. The amount of movement when moving in a direction opposite to the predetermined direction is accumulated, and the accumulated amount is subtracted from the amount of movement of the printing medium in the predetermined direction. Laser marking method described in.