JP2004042072A - Laser marking method and marking apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser marking method for highly accurately controlling a laser beam in forming a dot. <P>SOLUTION: A laser controlling apparatus 40 has a drive-pulse generating part 50 generating a driving pulse in a required interval and is connected to a setting panel wherein a number of irradiating times of the laser beam is input when forming a dot on a X-ray film 12. This laser controlling apparatus irradiates the laser beam on the same point of the X-ray film 12 only with the number of irradiating times that is set when a laser generator is driven by the driving pulse and the laser beam is irradiated on the X-ray film 12 to form a dot. Therefore, an irradiated volume of the laser beam on the X-ray film 12 can be highly accurately controlled by suitably setting the number of irradiating times. <P>COPYRIGHT: (C)2004,JPO

Description

【００７８】
表１で明らかなように、同じレーザー発振器４４を用いてマーキングパターンＭＰを形成するときに、吸収係数の異なるＸレイフィルム１２（試料１〜試料４）の何れであっても、レーザービームＬＢの照射回数Ｎを、適正に設定することにより、視認性の高いマーキングパターンＭＰを形成することができる。
【００７９】
Ｘレイフィルム１２に形成するマーキングパターンＭＰの視認性の向上を図るためには、乳剤層１６に微小な気泡１６Ｂを形成する必要がある。このとき、レーザービームＬＢの熱エネルギーが不足すると、気泡１６Ｂが少なかったり、気泡１６Ｂが生じなくなる。
【００８０】
また、熱エネルギーが必要以上に多くなると、乳剤層１６やベース層１４を完全に溶融させて、Ｘレイフィルム１２に穴開きを生じさせてしまう。さらに、乳剤層１６の溶融までに至らなくても、ベース層１４と乳剤層１６との間の境界面に微小な気泡１６Ｂとは異なる空間を生じさせてしまう。この空間は、レーザービームＬＢを照射してドット１６Ａを形成した時点では、ドット１６Ａの視認性が高くなるが、Ｘレイフィルム１２に対して現像処理を施すことで、この空間の上部側の乳剤層１６が飛散して開口してしまうことになり、レーザービームＬＢの照射時間を必要以上に長くしてドット１６Ｂを形成したときと同等の状態となってしまう。
【００８１】
このようなドット１６Ａの形成不良を防止するためには、レーザービームＬＢの照射時間（熱エネルギー）の高精度な制御が必要となる。また、適正なドット１６Ａを形成するために必要な熱エネルギー量は、Ｘレイフィルム１２の吸収係数によって異なる。
【００８２】
このとき、マーキング装置１０では、１回のレーザービームＬＢの照射時間を短くして、複数回に分割して、Ｘレイフィルム１２の同一位置にレーザービームＬＢを照射すると共に、このときのレーザービームＬＢの照射回数Ｎを、Ｘレイフィルム１２の品種（吸収係数などの差）等によって設定することにより、レーザービームＬＢの照射量を適正に制御する。これにより、マーキング装置１０では、何れのＸレイフィルム１２にも、適正なドット１６Ａを形成することができるようにしている。
【００８３】
また、マーキング装置１０では、レーザービームＬＢの照射間隔となる駆動パルスＤｐのインターバルｉｔを、１０ｎｓｅｃ以上とすることにより、前回のレーザービームＬＢの照射によるプルームが、次にＸレイフィルム１２に照射するレーザービームを遮ってしまったり、飛散物が次にＸレイフィルム１２に照射されるレーザービームＬＢによって発光して、Ｘレイフィルム１２に被り等の仕上り品質の低下を生じさせてしまうことがないようにしている。
【００８４】
すなわち、１回のレーザービームＬＢの照射時間を短くすることにより、１回に照射されるレーザービームＬＢのエネルギーが少なくなり、このレーザービームＬＢが、飛散物やＸレイフィルム１２の表面の塵埃に照射されたり、Ｘレイフィルム１２の内部の不純物に照射されても、これらの不純物を加熱してしまうことがない。
【００８５】
したがって、飛散物、塵埃、不純物等が加熱されることによる被り等によってＸレイフィルム１２の製品品質が低下してしまうのを防止することがでる。
【００８６】
さらに、１回のレーザービームＬＢの照射時間を短くした場合、レーザービームＬＢの連続出力よりもピーク出力が高くなるために、エネルギー効率の向上を図ることができる。
【００８７】
なお、以上説明した本実施の形態は、本発明の構成を限定するものではない。例えば、本実施の形態では、レーザー発振器４４を駆動する駆動パルスＤｐのパルス幅Δｔを一定にし、照射回数Ｎを制御するように説明したが、照射回数Ｎに加えて、パルス幅Δｔを制御するようにしても良い。
【００８８】
すなわち、駆動パルス発生部５０は、駆動パルスＤｐの発振周波数を可変できるものであっても良い。このときにおいても、少なくともインターバルｉｔを１０ｎｓｅｃ以上とすることが好ましい。
【００８９】
また、本実施の形態では、設定パネル５２のキー操作によってレーザービームＬＢの照射回数Ｎを入力するよに説明したが、これに限らず、マーキング処理するＸレイフィルム１２の品種情報（感材情報）等に基づいて予め照射回数Ｎが設定されており、Ｘレイフィルム１２の品種情報等が入力されることにより、この品種情報に基づいて照射回数Ｎが適切に設定されるものであっても良い。
【００９０】
すなわち、レーザービームＬＢの照射回数Ｎを多くすると、Ｘレイフィルム１２上に一つのドット１６Ａを形成するのに時間がかかり、Ｘレイフィルム１２が副走査方向に搬送されていると、ドット１６Ａが楕円状になるなどして崩れる。このとき、駆動パルスＤｐの発振周波数を低くして、パルス幅Δｔを長くすることにより、ドット１６Ａの形成時間の短縮を図ることが可能となり、レーザー発振器４４で発振するレーザービームＬＢに対する吸収係数の低いＸレイフィルム１２であっても、適正なドット１６Ａの形成が可能となる。
【００９１】
このようなレーザービームＬＢの照射時間となる駆動パルスＤｐのパルス幅Δｔは、この時間内に照射されるレーザービームＬＢのエネルギーが、飛散物、塵埃、不純物等を加熱してしまうことがない時間に設定することが好ましい。
【００９２】
なお、本実施の形態では、レーザー発振器（ＣＯ_２レーザー）４４から射出されるレーザービームＬＢを主走査しながら、Ｘレイフィルム１２を副走査する系を例に挙げたが、前記主走査方向に複数のレーザー発振器４４（ＣＯ_２レーザー）を配列し、これを同時に照射した状態でＸレイフィルム１２を搬送する系においても適用可能である。
【００９３】
また、以上説明した本実施の形態では、感光材料として、ＰＥＴを支持体とするＸレイフィルム１２を例に説明したが、Ｘレイフィルム１２としては、ＰＥＮ等の他の支持体を用いたものであっても良く、また、Ｘレイフィルム１２に限らず、任意の構成の感光材料のマーキングに適用することができる。
【００９４】
【発明の効果】
以上説明したように本発明によれば、照射回数を適切に設定することにより、感光材料に照射するレーザービームの照射時間を高精度に制御することができるので、吸収係数の異なる感光材料のそれぞれに適正なドットを形成してマーキングパターンを印字することができるという優れた効果が得られる。
【００９５】
また、本発明では、レーザービームによって塵や埃等が加熱されることがないので、感光材料に仕上り品質の低下を生じさせてしまうことがない。
【図面の簡単な説明】
【図１】本実施の形態に適用したマーキング装置の概略構成図である。
【図２】（Ａ）は本実施の形態に適用したＸレイフィルムの概略構成図、（Ｂ）はドットが形成されたＸレイフィルムの概略構成図である。
【図３】マーキングヘッドが設けられているプリントロール近傍の概略構成を示す要部斜視図である。
【図４】マーキングパターンを形成したＸレイフィルムの概略平面図である。
【図５】（Ａ）は駆動パルス発生部で発生する駆動パルスを示す線図、（Ｂ）はＸレイフィルムの同一位置に照射されるレーザービームのオン／オフの概略を示す線図である。
【符号の説明】
１０　　マーキング装置
１２　　Ｘレイフィルム（感光材料）
１４　　ベース層
１６　　乳剤層
１６Ａ　　ドット
１６Ｂ　　気泡
２４　　プリントロール
３２　　サクションドラム
３８　　ロータリーエンコーダ
４０　　レーザー制御装置（マーキング制御手段）
４２　　マーキングヘッド
４４　　レーザー発振器（レーザー発振手段）
４６　　ビーム偏向器（ビーム偏向手段）
５０　　駆動パルス発生部（駆動パルス発生手段）
５２　　設定パネル（設定手段）
５４　　パルス制限部
ＭＰ　　マーキングパターン
Δｔ　　パルス幅
ｉｔ　　インターバル
Ｎ　　照射回数[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser marking method and a marking apparatus for forming a dot-shaped marking pattern by irradiating a photographic photosensitive material such as an X-ray film with a laser beam.
[0002]
[Prior art]
As a technique for marking characters, symbols and the like on the surface of a material using laser light, for example, JP-A-10-305377 is cited. In Japanese Patent No. 3191201 (hereinafter referred to as “prior art”), a photosensitive material such as an X-ray film is irradiated with a laser beam to cause dot-like heat coverage or deformation on the surface of the photosensitive material. A marking technique has been proposed in which characters and symbols are formed by the dot arrangement.
[0003]
Further, in this prior art, the laser beam irradiation time per dot (laser beam irradiation time per dot, which is the pulse width when driving the laser oscillator) is set to 30 μsec or more, so that the dots can be visually recognized. The heat covering and the deformation | transformation which can improve a property are produced.
[0004]
By the way, in order to form dots of an appropriate size and shape on an X-ray film by scanning with a laser beam, it is necessary to appropriately control the amount of energy of the laser beam. Examples include beam intensity and irradiation time.
[0005]
The irradiation time of the laser beam can be easily controlled by the pulse width when driving a laser oscillator such as a laser oscillation tube, and the intensity of the laser beam is determined by the laser oscillator. From this point, when increasing the amount of energy applied to the X-ray film, it is possible to increase the pulse width to increase the irradiation time, or to use a laser oscillator with a large output.
[0006]
However, when scanning a laser beam while transporting an X-ray film, the irradiation time of the laser beam is limited to the transport speed of the X-ray film. That is, when the pulse width for driving the laser oscillator is increased, the irradiation region of the laser beam for forming one dot extends in the transport direction, which is the sub-scanning direction, and the dot shape is destroyed.
[0007]
In addition, when the irradiation time of the laser beam is long, there is a problem that surrounding dust or dust heated by the laser beam burns, and the X-ray film is covered.
[0008]
Furthermore, if the absorption coefficient for a laser beam is high in a photosensitive material to be printed such as an X-ray film, it may be necessary to reduce the intensity of the laser beam. Therefore, it is sometimes impossible to form appropriate dots on a photosensitive material having a high absorption coefficient.
[0009]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned facts, and when a photosensitive material such as an X-ray film is irradiated with a laser beam to form a dot-like marking pattern, the laser beam irradiation amount can be controlled appropriately. An object of the present invention is to propose a laser marking method and a marking apparatus.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the laser marking method of the present invention comprises a laser having a predetermined wavelength oscillated by a laser oscillator on a photosensitive material in which an emulsion layer serving as a photosensitive layer is formed on at least one surface of a base layer serving as a support. A laser marking method for forming a dot-shaped marking pattern on a photosensitive material with dots formed by irradiating a beam, wherein the laser beam is irradiated to the same position of the photosensitive material a predetermined number of times. The dot forming the marking pattern is formed.
[0011]
According to the present invention, the laser beam is divided into a predetermined number of times to form dots on the photosensitive material. That is, the amount of laser beam irradiation necessary to form dots on the photosensitive material is divided and irradiated onto the photosensitive material.
[0012]
Thereby, it is possible to form appropriate dots on the photosensitive material by appropriately setting the number of times of laser beam irradiation. At this time, since the irradiation time of one laser beam is not lengthened, the surrounding dust, dust, and the like are not heated to cause a defective finish in the photosensitive material.
[0013]
Moreover, in the laser marking method of this invention, it is preferable that the time interval which irradiates the said laser beam to the same position on the said photosensitive material shall be 10 nsec or more.
[0014]
By irradiating the laser beam, a plume (scattered matter) is generated in the photosensitive material in the photosensitive material. By setting the laser beam irradiation interval to 10 nsec or more, the laser beam is irradiated avoiding the peak of the plume. Therefore, it is possible to prevent the plume from being heated by the laser beam and causing defective finishing in the photosensitive material.
[0015]
The marking device according to the present invention also has a predetermined marking pattern based on an array of dots formed by irradiating a photosensitive material having an emulsion layer serving as a photosensitive layer on at least one surface of a base layer serving as a support. A laser oscillating unit having a predetermined output for emitting the laser beam at a predetermined oscillation wavelength, a beam deflecting unit for deflecting the laser beam oscillated by the laser oscillating unit, a predetermined pulse width and The number of drive pulses generated by the drive pulse generating means for generating a pulse for driving the laser oscillating means at a predetermined time interval and the drive pulse generating means for forming one dot on the photosensitive material is set. Setting means, and the beam deflection means based on the pattern signal of the marking pattern A direction signal and a driving pulse generated by the driving pulse generating means are output to the laser oscillating means to irradiate the photosensitive material with the laser beam and to irradiate a laser beam when forming one dot on the photosensitive material. Marking control means for controlling the number of times to be the number set in the setting means.
[0016]
According to the present invention, the laser oscillating means is driven by the driving pulse having a predetermined pulse width generated by the driving pulse generating means. As a result, the laser oscillation means emits a laser beam with the pulse width of the drive pulse.
[0017]
At this time, an appropriate amount of laser beam irradiation corresponding to the absorption coefficient of the photosensitive material can be obtained by outputting the number of drive pulses corresponding to the number of times set by the setting means to the laser oscillation means to form one dot.
[0018]
In such a marking apparatus of the present invention, it is preferable that the setting means includes an input means for inputting the number of drive pulses, and thereby, a laser beam corresponding to the absorption coefficient of the photosensitive material to be marked is irradiated. I can do it.
[0019]
Further, the drive pulse generating means may be capable of changing the pulse width and period (frequency) of the drive pulse, and this is preferable because the irradiation amount of one racer beam can be easily changed. .
[0020]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic configuration of a marking device 10 applied to the present embodiment. This marking device 10 irradiates the surface with a laser beam (light beam) LB in the process of transporting an X-ray film 12 which is a kind of photographic photosensitive material as a printing object, and forms marking patterns such as characters and symbols. Apply the marking process to be formed.
[0021]
As shown in FIG. 2A, the X-ray film 12 is obtained by forming an emulsion layer 16 that becomes a photosensitive layer on at least one surface of a base layer 14 that is a support made of PET (polyethylene terephthalate). . As shown in FIG. 1, the X-ray film 12 is loaded into the marking device 10 while being wound around the core 18 in a roll shape.
[0022]
In the marking device 10, the X-ray film 12 is pulled out from the outermost layer. At this time, the X-ray film 12 is drawn out with the surface on the emulsion layer 16 side facing upward in FIG.
[0023]
The X-ray film 12 drawn out from the outermost layer is wound around the pass roll 20, changed in direction from the advancing direction (arrow A direction in FIG. 1) upward at a substantially right angle, and wound around the pass roll 22. Further, the X-ray film 12 is wound around a pass roll 22, changed in direction substantially at right angles to the traveling direction, and reaches the print roll 24.
[0024]
In the marking device 10, the position wound around the print roll 24 is set as the irradiation position of the laser beam LB, and the X-ray film 12 whose direction is changed substantially perpendicularly from the traveling direction by the print roll 24 is: It is sandwiched between the rolls 26 arranged in pairs and is turned substantially at right angles to the traveling direction and sent to the small rolls 28 and 30.
[0025]
A suction drum 32 is disposed between the small rolls 28 and 30, and the suction drum 32 forms a substantially U-shaped conveyance path between the small rolls 28 and 30. The small rolls 28 and 30 are wound around the suction drum 32.
[0026]
The suction drum 32 is provided with a plurality of small holes (not shown) on the outer peripheral surface, sucks and holds the X-ray film 12 wound around the peripheral surface by air suction, and with its own weight or a biasing force of a biasing means (not shown). 1 can be moved downward in FIG. As a result, since the back tension is applied to the X-ray film 12, the X-ray film 12 is kept in close contact with the print roll 24 when passing through the print roll 24.
[0027]
The X-ray film 12 sent out from the roll 26 is conveyed between the pair of small rolls 28 and 30 in a substantially U shape, sent out from the small roll 30, and passed through the small roll 30. 34 is wound up.
[0028]
On the other hand, the marking device 10 is provided with a winding control device 36, and the winding cores 18 and 34 and the suction drum 32 are motors that rotate at a predetermined rotational speed in response to a drive signal from the winding control device 36. It is rotationally driven by the driving force of the driving means (not shown). Thereby, the X-ray film 12 is conveyed from the core 18 side to the core 34 side.
[0029]
In the marking device 10, the cores 18 and 34 are rotationally driven so that the X-ray film 12 is conveyed at the same linear velocity, and the suction drum 32 rotates while adsorbing and holding the X-ray film 12. Therefore, the rotational speed of the suction drum 32 matches the transport speed (line speed) of the X-ray film 12 on the print roll 24.
[0030]
A rotary encoder 38 is attached to the suction drum 32, and a pulse signal corresponding to the rotation angle of the suction drum 32 is output.
[0031]
Further, the marking device 10 is provided with a marking head 42 for emitting the laser beam LB and a laser control device 40 for controlling the emission of the laser beam, and the output signal (pulse signal) of the rotary encoder 38 is the laser control device 40. To be input.
[0032]
As shown in FIGS. 1 and 3, the marking head 42 has a laser beam LB exit port, which is the tip of the marking head 42, facing the print roll 24. The marking head 42 includes a laser oscillator 44 as laser oscillating means, a beam deflector 46 including a condensing lens (not shown) as beam deflecting means, and a laser beam LB emitted from the laser oscillator 44 is applied to a print roll. Injected toward the X-ray film 12 wound around 24.
[0033]
As an example, the laser oscillator 44 applied to this embodiment is a CO 2.₂A laser oscillation tube that emits a laser is provided, and a laser beam having a constant oscillation wavelength determined by the laser oscillation tube at a predetermined timing based on a drive signal (drive pulse) from a laser control device 40 (not shown in FIG. 3). LB is emitted with a time width of a drive pulse input as a drive signal.
[0034]
The beam deflector 46 includes, for example, an AOD (acoustooptic device), and has a function of scanning the laser beam LB in a direction orthogonal to the transport direction of the X-ray film 12 by a deflection signal from the laser control device 40. ing. Each scanned laser beam LB is imaged on the X-ray film 12 by the condenser lens so as to be focused at a predetermined spot diameter.
[0035]
As shown in FIG. 2 (B), the X-ray film 12 is expanded in the process in which the emulsion layer 16 is melted and deposited by the thermal energy of the laser beam LB when the laser beam LB is irradiated in a spot shape. Dots 16A are formed by generating a plurality of fine bubbles 16B inside.
[0036]
At this time, in the X-ray film 12, a plurality of fine bubbles 16B are formed in the emulsion layer 16, so that a large number of boundary films are formed between the bubbles 16B. The amount of reflected light greatly changes inside and outside 16A, thereby forming dots 16A that can be viewed regardless of whether the X-ray film 12 is undeveloped or developed, or whether the density is dark or shaded. In the marking device 10, a marking pattern MP such as a character, a symbol, or a character is formed by the A array of dots 16 (see FIGS. 3 and 4).
[0037]
A pattern signal corresponding to the marking pattern MP to be recorded on the X-ray film 12 is input from the winding control device 36 to the laser control device 40. The laser controller 40 drives the laser oscillator 44 according to the pattern signal while monitoring the transport length of the X-ray film 12 based on the pulse signal output from the rotary encoder 38 according to the transport of the X-ray fill 12. A signal is output and a deflection signal is output to the beam deflector 46.
[0038]
Thereby, the marking head 42 scans on the X-ray film 12 while turning on / off the laser beam LB according to the marking pattern MP.
[0039]
At this time, as shown in FIG. 3, in the marking device 10, the X-ray film 12 is conveyed at a predetermined line speed, so that the scanning direction of the laser beam LB by the beam deflector 46 is the main scanning direction. A marking pattern (here, alphabet) MP is formed on the X-ray film 12 with the transport direction of the lay film 12 (arrow direction in FIG. 3) as the sub-scanning direction.
[0040]
As shown in FIGS. 3 and 4, as the marking pattern MP, for example, a character, a symbol, a character, or the like formed by a predetermined dot arrangement such as 5 × 5 dots can be used. Further, the marking pattern MP can be formed with an arbitrary configuration such as using a plurality of characters, symbols, and the like formed by dot arrangement.
[0041]
In such a marking device 10, when the X-ray film 12 is cut in the longitudinal direction (the cut line 48 is indicated by a broken line) and processed into a narrow roll shape or a sheet shape, both sides of the cut line 48 are sandwiched. It is also possible to form a marking pattern MP in which the orientation of the top and bottom is reversed.
[0042]
As shown in FIGS. 1 and 3, when the X-ray film 12 is wound around the print roll 24, the marking head 42 is positioned slightly lifted from the peripheral surface of the print roll 24. As a result, the laser beam LB transmitted through the X-ray film 12 heats the dust and dirt adhering to the peripheral surface of the print roll 24 and covers the X-ray film 12. Is prevented.
[0043]
By the way, as shown in FIG. 1, the laser control device 40 is provided with a drive pulse generator 50 that generates a drive pulse for driving the laser oscillator 44. As shown in FIG. 5A, the drive pulse generator 50 generates a drive pulse Dp having a pulse width Δt at an interval it.
[0044]
When the laser control device 40 drives the laser oscillator 44, the drive pulse Dp is output to the laser oscillator 44. Thus, the laser oscillator 44 has a pulse width Δt at intervals of the interval it. The laser beam LB is generated for a time corresponding to.
[0045]
As shown in FIG. 1, the marking device 10 is provided with a setting panel 52, and this setting panel 52 is connected to the laser control device 40. The laser control device 40 is provided with a pulse limiter 54.
[0046]
In the marking device 10, the number N of irradiation times of the laser beam LB emitted with the pulse width Δt when one dot 16 </ b> A is formed on the X-ray film 12 is set by a key operation (not shown) of the operation panel 52. Further, the pulse limiting unit 54 of the laser control device 40 limits the number of drive pulses Dp output to the laser oscillator 44 to the number of irradiations N when one dot is formed.
[0047]
As a result, as shown in FIG. 5B, the laser control device 40 uses the operation panel 52 to irradiate the laser beam LB on the X-ray film 12 based on the pattern signal corresponding to the marking pattern MP. The laser beam LB is irradiated for the set number of irradiation times N to form individual dots 16A constituting the marking pattern MP on the X-ray film 12.
[0048]
The pulse limiting unit 54 may directly limit the number of drive pulses Dp output to the laser oscillator 44, and drives the laser oscillator 44 by continuously outputting the drive pulses Dp. However, the number of times of irradiation of the laser beam LB to the same position on the X-ray film 12 may be limited by a deflection signal output to the beam deflector 46.
[0049]
On the other hand, in the marking device 10, the number of irradiations N is set based on the pulse width Δt of the drive pulse Dp, the output of the laser oscillator 44, the oscillation wavelength, the absorption coefficient of the X-ray film 12 with respect to the laser beam LB, and the like. It has become.
[0050]
Thereby, in the marking apparatus 10, the appropriate dot 16A with high visibility is formed on the X-ray film 12.
[0051]
That is, the laser control unit 40 irradiates the X-ray film 12 with the laser beam LB so as to divide the energy of the laser beam LB necessary for forming an appropriate dot 16A on the X-ray film 12 into a plurality of times. Like to do.
[0052]
At this time, the oscillation wavelength and output of the laser beam LB emitted from the marking head 42 are determined by the laser oscillator 44. If the pulse width Δt of the drive pulse Dp, which is the irradiation time of one laser beam LB, is constant, the laser beam LB when forming one dot on the X-ray film 12 by changing the number of irradiations N. The energy of can be changed.
[0053]
In the marking device 10, the number of irradiation times N is set according to the absorption coefficient of the X-ray film 12, thereby forming the dots 16 </ b> A having high visibility without causing the X-ray film 12 to be covered or blank. can do.
[0054]
In the marking apparatus 10, the X ray film 12 having a pulse width Δt of the driving pulse Dp and a fluence of the laser beam LB output from the marking head 42 by one driving pulse Dp has the highest absorption coefficient with respect to the laser beam LB. The number of dots 16A is set to be smaller than that for forming the proper dots 16A.
[0055]
The pulse width Δt when the X-ray film 12 is irradiated with the laser beam LB can be set in a range of 100 nsec (0.1 μsec) to 10 μsec (0.1 μsec ≦ Δt ≦ 10 μsec). Further, the pulse width Δt can be processed even if it is set at a time outside the above range from the appropriateness of the material of the irradiated object and the oscillation wavelength of the laser beam LB.
[0056]
On the other hand, when the X-ray film 12 is irradiated with the laser beam LB, a plume (scattered matter) is generated, and this plume blocks the next emitted laser beam LB, or the scattered matter is irradiated with the laser beam LB. As a result, light is emitted and the X-ray film 12 is covered.
[0057]
From here, in the marking apparatus 10, the interval it of the drive pulse Dp is set to 10 nsec or more so that the laser beam LB is not emitted until the peak of the plume passes.
[0058]
As described above, the X-ray film 12 is irradiated with the laser beam LB in the form of a spot, so that the emulsion layer 16 is melted and vapor-deposited by the energy (thermal energy) of the laser beam LB. Bubbles 16B are generated (see FIG. 2B). Thereby, convex dots 16 </ b> A with respect to the emulsion layer 16 are formed on the X-ray film 12.
[0059]
At this time, in this embodiment, the laser beam LB irradiated to the X-ray film 12 is imaged on the X-ray film 12 with a beam diameter of 0.1 mm, and dots formed on the emulsion layer 16 are formed. The outer diameter of 16A is about 100 μm (about 0.1 mm), the convex amount of the dots 16A is 10 μm or less, and the size (diameter) of each bubble 16B is 1 to 5 μm.
[0060]
Further, the oscillation wavelength of the laser beam LB in the laser oscillator 44 may be in a 10 μm band (for example, 10.6 μm) or in a 9 μ band (for example, a wavelength of 9.3 μm, 9.6 μm, etc.). .
[0061]
In the marking device 10 configured as described above, the X-ray film 12 wound around the core 18 is started to be pulled out by the drive signal output from the winding control device 36, and the X-ray film 12 The conveyance and winding to the core 34 are started.
[0062]
The suction drum 32 is controlled by the winding control device 36 and starts sucking air while rotating, thereby sucking and holding the X-ray film 12 wound around the circumferential surface. Thereby, the X-ray film 12 is sent out while being pulled in at a predetermined line speed. At this time, the suction drum 32 applies a predetermined tension to the X-ray film 12 by its own weight or the urging force of the urging means.
[0063]
As a result, the rotational speed (circumferential speed) of the suction drum 32 becomes a reference line speed for the transport system of the X-ray film 12, and the line speed of the X-ray film 12 on the print roll 24 is the peripheral speed of the suction drum 32. Matches.
[0064]
The laser control device 40 detects the rotation state of the suction drum 32 by the rotary encoder 38. The laser control device 40 is supplied with a pattern signal corresponding to the marking pattern MP to be recorded on the X-ray film 12 from the winding control device 36.
[0065]
Here, the laser control device 40 monitors the transport length of the X-ray film 12 based on the pulse signal output from the rotary encoder 38. For example, the transport length of the X-ray film 12 is set to a preset length. The laser oscillator (CO based on the pattern signal)₂A drive signal is output to the laser 44 and a deflection signal is output to the beam deflector 46.
[0066]
Thereby, the laser beam LB emitted from the laser oscillator 44 is irradiated while being scanned on the X-ray film 12 wound around the print roll 24, and the X-ray film 12 is marked with dots according to the pattern signal. A pattern MP is formed.
[0067]
By the way, in the marking device 10, the marking head 42 has CO 2.₂A laser oscillator 44 having a predetermined output that emits a laser is used, and the laser controller 40 irradiates the X-ray film 12 with the laser beam LB by driving the laser oscillator 44 with a drive pulse Dp.
[0068]
On the other hand, the laser control device 40 is provided with a drive pulse generation unit 50, and the drive pulse generation unit 50 generates a drive pulse Dp having a pulse width Δt at intervals of an interval it. By driving the laser oscillator 44 using this drive pulse Dp, the X-ray film 12 can be irradiated with the laser beam LB of the irradiation time Δt at the interval it.
[0069]
In addition, the marking device 10 is provided with a setting panel 52. By inputting the number of times of irradiation N of the laser beam LB per dot in advance by operating the key on the setting panel 52, the laser control unit 40 performs pulse The limiter 54 limits the number of drive pulses Dp that drive the laser oscillator 44.
[0070]
That is, the laser control device 40 irradiates the same position on the X-ray film 12 with one laser beam LB corresponding to the number of irradiation times N input to the setting panel 52, thereby causing one dot on the X-ray film 12. 16A is formed.
[0071]
At this time, by appropriately setting the number of irradiations N of the laser beam LB in accordance with the absorption coefficient of the X-ray film 12, appropriate dots 16A are formed on the X-ray film 12, and a marking pattern MP with high visibility is formed. Can be formed.
[0072]
Table 1 shows the number of irradiation times N of the laser beam LB with respect to each of the sample 1, the sample 2, the sample 3, and the sample 4 having different absorption coefficients with respect to the laser beam LB oscillated by the laser oscillator 44. The result of the evaluation of the finished dot 16A is shown.
[0073]
The evaluation shown in Table 1 is
○: A dot (marking pattern) can be well distinguished.
[0074]
Δ: It can be discriminated by reflection, or a state just before the hole is opened.
[0075]
×: Cannot be discriminated at all (no trace) or a hole has been opened.
It is said.
[0076]
In Table 1, the fluence of the laser beam LB irradiated at one time is 2.5 J / cm.²Sample 1 to Sample 4 have an absorption coefficient a₁, A₂, A₃, A₄But,
a₁> A₂> A₃> A₄
It has become.
[0077]
[Table 1]

[0078]
As is apparent from Table 1, when the marking pattern MP is formed using the same laser oscillator 44, the X-ray film 12 (Sample 1 to Sample 4) having different absorption coefficients can be used for the laser beam LB. A marking pattern MP with high visibility can be formed by appropriately setting the number of times of irradiation N.
[0079]
In order to improve the visibility of the marking pattern MP formed on the X-ray film 12, it is necessary to form minute bubbles 16B in the emulsion layer 16. At this time, if the thermal energy of the laser beam LB is insufficient, the number of bubbles 16B is small or the bubbles 16B are not generated.
[0080]
Further, when the thermal energy is increased more than necessary, the emulsion layer 16 and the base layer 14 are completely melted, and the X-ray film 12 is perforated. Further, even if the emulsion layer 16 does not reach melting, a space different from the minute bubbles 16B is generated at the interface between the base layer 14 and the emulsion layer 16. This space becomes highly visible when the dot 16A is formed by irradiating the laser beam LB. However, by developing the X-ray film 12, the emulsion on the upper side of the space is exposed. The layer 16 will scatter and open, resulting in a state equivalent to that when the dot 16B is formed by making the irradiation time of the laser beam LB longer than necessary.
[0081]
In order to prevent such defective formation of the dots 16A, it is necessary to control the irradiation time (thermal energy) of the laser beam LB with high accuracy. Further, the amount of heat energy necessary for forming the proper dots 16 </ b> A varies depending on the absorption coefficient of the X-ray film 12.
[0082]
At this time, the marking device 10 shortens the irradiation time of one laser beam LB, divides the laser beam LB into a plurality of times, and irradiates the laser beam LB at the same position of the X-ray film 12. By setting the number N of LB irradiations according to the type of X-ray film 12 (difference in absorption coefficient or the like), the irradiation amount of the laser beam LB is appropriately controlled. As a result, the marking device 10 can form appropriate dots 16 </ b> A on any X-ray film 12.
[0083]
Further, in the marking device 10, by setting the interval it of the drive pulse Dp, which is the irradiation interval of the laser beam LB, to 10 nsec or more, the plume due to the previous irradiation of the laser beam LB irradiates the X-ray film 12 next. The laser beam is not interrupted, and scattered objects are not emitted by the laser beam LB irradiated to the X-ray film 12 next, and the X-ray film 12 is not deteriorated in finish quality such as covering. I have to.
[0084]
That is, by shortening the irradiation time of one laser beam LB, the energy of the laser beam LB irradiated once is reduced, and this laser beam LB is applied to scattered matter and dust on the surface of the X-ray film 12. Irradiation or irradiation of impurities inside the X-ray film 12 does not heat these impurities.
[0085]
Therefore, it is possible to prevent the product quality of the X-ray film 12 from being deteriorated due to covering caused by heating of scattered matter, dust, impurities, and the like.
[0086]
Furthermore, when the irradiation time of one laser beam LB is shortened, the peak output becomes higher than the continuous output of the laser beam LB, so that energy efficiency can be improved.
[0087]
In addition, this Embodiment demonstrated above does not limit the structure of this invention. For example, in the present embodiment, it has been described that the pulse width Δt of the drive pulse Dp for driving the laser oscillator 44 is made constant and the number of times of irradiation N is controlled, but in addition to the number of times of irradiation N, the pulse width Δt is controlled. You may do it.
[0088]
That is, the drive pulse generator 50 may be one that can vary the oscillation frequency of the drive pulse Dp. Also at this time, it is preferable to set at least the interval it to 10 nsec or more.
[0089]
In the present embodiment, it has been described that the number of times of irradiation N of the laser beam LB is input by a key operation on the setting panel 52. However, the present invention is not limited to this. ) And the like, the number of irradiations N is set in advance, and by inputting the type information of the X-ray film 12, the number of irradiations N is appropriately set based on the type information. good.
[0090]
That is, if the number of times of irradiation N of the laser beam LB is increased, it takes time to form one dot 16A on the X-ray film 12, and when the X-ray film 12 is conveyed in the sub-scanning direction, the dot 16A is It collapses by becoming elliptical. At this time, by reducing the oscillation frequency of the drive pulse Dp and increasing the pulse width Δt, it is possible to shorten the formation time of the dots 16A, and the absorption coefficient of the laser beam LB oscillated by the laser oscillator 44 can be reduced. Even with the low X-ray film 12, appropriate dots 16A can be formed.
[0091]
The pulse width Δt of the drive pulse Dp, which is the irradiation time of the laser beam LB, is a time during which the energy of the laser beam LB irradiated within this time does not heat the scattered matter, dust, impurities, etc. It is preferable to set to.
[0092]
In this embodiment, a laser oscillator (CO₂An example has been given of a system in which the X-ray film 12 is sub-scanned while main-scanning the laser beam LB emitted from the laser 44, but a plurality of laser oscillators 44 (CO₂This is also applicable to a system in which the X-ray film 12 is transported in a state in which lasers are arranged and irradiated simultaneously.
[0093]
In the above-described embodiment, the X-ray film 12 using PET as a support is described as an example of the photosensitive material. However, the X-ray film 12 uses another support such as PEN. Further, the present invention is not limited to the X-ray film 12 and can be applied to marking of a photosensitive material having an arbitrary configuration.
[0094]
【The invention's effect】
As described above, according to the present invention, by appropriately setting the number of times of irradiation, the irradiation time of the laser beam applied to the photosensitive material can be controlled with high accuracy. An excellent effect is obtained in that an appropriate dot can be formed and a marking pattern can be printed.
[0095]
Further, in the present invention, dust, dust or the like is not heated by the laser beam, so that the finished quality of the photosensitive material is not deteriorated.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a marking device applied to the present embodiment.
2A is a schematic configuration diagram of an X-ray film applied to the present embodiment, and FIG. 2B is a schematic configuration diagram of an X-ray film on which dots are formed.
FIG. 3 is a perspective view of a main part showing a schematic configuration in the vicinity of a print roll provided with a marking head.
FIG. 4 is a schematic plan view of an X-ray film on which a marking pattern is formed.
5A is a diagram showing a drive pulse generated by a drive pulse generator, and FIG. 5B is a diagram showing an outline of on / off of a laser beam irradiated to the same position of an X-ray film. .
[Explanation of symbols]
10 Marking device
12 X-ray film (photosensitive material)
14 Base layer
16 Emulsion layer
16A dot
16B bubbles
24 print roll
32 Suction drum
38 Rotary encoder
40 Laser control device (marking control means)
42 Marking head
44 Laser oscillator (laser oscillation means)
46 Beam deflector (beam deflection means)
50 Drive pulse generator (drive pulse generator)
52 Settings panel (setting method)
54 Pulse limit section
MP marking pattern
Δt Pulse width
it interval
N Number of irradiation

Claims (4)

Dots are formed on the photosensitive material with dots formed by irradiating a photosensitive material with an emulsion layer serving as a photosensitive layer on at least one side of the base layer serving as a support to a laser beam of a predetermined wavelength oscillated by a laser oscillator. A laser marking method for forming a marking pattern of
A laser marking method, wherein dots forming the marking pattern are formed by irradiating the same position of the photosensitive material with the laser beam a predetermined number of times. 2. The laser marking method according to claim 1, wherein a time interval of irradiating the laser beam to the same position on the photosensitive material is set to 10 nsec or more. A marking device for forming a predetermined marking pattern by an array of dots formed by irradiating a photosensitive material having an emulsion layer serving as a photosensitive layer formed on at least one surface of a base layer serving as a support with a laser beam,
Laser oscillation means having a predetermined output for emitting the laser beam at a predetermined oscillation wavelength;
Beam deflecting means for deflecting the laser beam oscillated by the laser oscillating means;
Drive pulse generating means for generating a pulse for driving the laser oscillation means at a predetermined pulse width and a predetermined time interval;
Setting means for setting the number of drive pulses generated by the drive pulse generating means when forming one dot on the photosensitive material;
The photosensitive material is irradiated with the laser beam by outputting a deflection signal to the beam deflecting means and a driving pulse generated by the driving pulse generating means to the laser oscillating means based on a pattern signal of the marking pattern. Marking control means for controlling the number of times of irradiation of the laser beam when forming one dot on the photosensitive material to be the number set in the setting means;
A marking device comprising: 4. The marking apparatus according to claim 3, wherein the setting means includes an input means for inputting the number of drive pulses.

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