Laser irradiation device, and laser irradiation method

Abstract

To appropriately form a display pattern to each base material even when a pitch of a base material becomes uneven in the case that a pitch between bottles is narrowed so as to increase productivity.SOLUTION: A laser irradiation device has: an irradiation part for irradiating a base material to be conveyed to an irradiation area with laser light; a detection part for detecting an entrance timing of the base material into the irradiation region: and a control part for controlling irradiation of the laser light by the irradiation part. A pattern is formed on the surface of the base material by the laser light irradiated by the irradiation part. The control part determines an irradiation start position of the laser beam to the base material entering the irradiation region by the irradiation part in accordance with the entrance timing detected by the detection part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a laser irradiation device and a laser irradiation method. [Background technology]

[0002] BACKGROUND ART Conventionally, a technique for forming a pattern by irradiating a substrate such as a PET (Poly Ethylene Terephthalate) bottle with laser light has been known.

[0003] Furthermore, a processing method has been disclosed that can process a transported substrate even when the transport speed of the transported substrate is different (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a method of determining the irradiation start position based solely on the timing signal from the substrate sensor, if printing starts late on the leading substrate due to pitch variations and the next substrate enters the irradiation area early due to variations, the next substrate will enter the irradiation area earlier than expected even though printing on the leading substrate has not yet finished.As a result, printing on the leading substrate must be stopped halfway before writing on the next substrate can begin, or printing on the next substrate will not be possible at all, resulting in the problem of being unable to print on one of the substrates.

[0005] The present invention aims to properly form display patterns on each substrate even when the pitch between bottles is narrowed to increase productivity and variations occur in the pitch of the substrates. [Means for solving the problem]

[0006] A laser irradiation device according to one aspect of the present invention includes an irradiation unit that irradiates a substrate transported to an irradiation area with laser light, a detection unit that detects the timing of the substrate entering the irradiation area, and a control unit that controls the irradiation of the laser light by the irradiation unit, wherein a pattern is formed on the surface of the substrate by the laser light irradiated from the irradiation unit, and the control unit determines the start position of irradiation of the laser light by the irradiation unit onto the substrate entering the irradiation area, depending on the entry timing detected by the detection unit. [Effects of the Invention]

[0007] According to the present invention, when the pitch between bottles is narrowed to increase productivity, even if there is variation in the pitch of the substrates, the display pattern can be formed appropriately on each substrate. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a top view showing an example of the configuration of a laser irradiation device 200 according to an embodiment of the present invention. [Figure 2] 1 is a side view showing an example of the configuration of a laser irradiation device 200 according to an embodiment of the present invention. [Figure 3] FIG. 1 is a diagram illustrating a pitch dividing device for a substrate. [Figure 4] FIG. 10 is a diagram illustrating an example of pitch allocation variation. [Figure 5] 10 is a diagram showing an example of a deviation between an ideal pulse of the pitch division of the substrate and a detection signal by a detection unit. FIG. [Figure 6] 5 is a flowchart showing a first example of the operation of the laser irradiation device according to the embodiment of the present invention. [Figure 7] 5 is a diagram showing an example of the relationship between a detection signal of a substrate detected by a detection unit, an irradiation reference pulse, and an irradiation signal. FIG. [Figure 8] FIG. 2 is an image diagram illustrating the setting range of the irradiation reference pulse expressed by the formula (1). [Figure 9] 6 is a flowchart showing a second example of the operation of the laser irradiation device according to the embodiment of the present invention. [Figure 10] 5 is a diagram showing an example of the relationship between a detection signal of a substrate detected by a detection unit, an irradiation reference pulse, and an irradiation signal. FIG. [Figure 11] FIG. 10 is a diagram showing an example of the configuration of a laser irradiation device according to a modified example. [Figure 12] FIG. 10 is a conceptual diagram showing an example of an operation algorithm for irradiating a substrate with laser light using n irradiation units. [Figure 13] FIG. 2 is a diagram showing an example of a pattern formed on the surface of a substrate. [Figure 14] 2 is a block diagram showing an example of a hardware configuration of a control unit included in the laser irradiation device according to the embodiment of the present invention. FIG. [Figure 15] FIG. 2 is a block diagram showing an example of a functional configuration of a control unit included in the laser control device according to the embodiment of the present invention. [Figure 16] 4 is a sequence chart showing an example of a detailed operation of the laser irradiation device according to the embodiment of the present invention. [Figure 17] FIG. 10 is a diagram showing an example of a change in the property of a substrate. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0010] Furthermore, the embodiments shown below are illustrative of a laser irradiation device and a laser irradiation method for embodying the technical concept of the present invention, and the present invention is not limited to the embodiments shown below. The dimensions, materials, shapes, relative positions, etc. of the components described below are intended for illustrative purposes only, and are not intended to limit the scope of the present invention unless otherwise specified. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity. In the drawings of the embodiments, the transport direction of the substrate is the X-axis direction, the intersecting direction with the X-axis direction is the Y-axis direction, and the direction of gravity intersecting with both the X-axis direction and the Y-axis direction is the Z-axis direction.

[0011] [Embodiment] The substrate in the embodiment refers to the material portion of an object. Examples of the object include a substrate that contains a beverage or the like. Examples of the substrate include a PET bottle that contains a beverage and is made of a resin such as PET. However, there are no particular limitations on the object, and it can be any object. There are also no limitations on the shape or material of the substrate, and it can be a substrate of any shape and made of any material.

[0012] The surface of the substrate means the surface of the material that is in contact with the external air, etc. In the embodiment, the term "surface of the substrate" is used as a term that is symmetrical to the interior of the substrate, so that, for example, in the case of a plate-shaped substrate, both the front and back surfaces of the substrate correspond to the surface of the substrate. In addition, in the case of a cylindrical substrate, both the outer and inner surfaces of the substrate correspond to the surface of the substrate.

[0013] The pattern includes characters, codes such as barcodes, figures, images, etc., and displays information about the substrate or the contents contained therein, such as the name, identification number, manufacturer, production date and time, etc., of the substrate or the contents contained therein, such as a beverage. In the case of substrates such as PET bottles, this information may be displayed by attaching a recording medium (label) on which this information is recorded to the surface of the substrate. In an embodiment, by forming a pattern indicating this information on the surface of the substrate constituting the substrate, it is possible to display the above information on the substrate in a so-called label-less manner, without using a recording medium.

[0014] <Configuration of laser irradiation device according to an embodiment of the present invention> First, the configuration of a laser irradiation device according to an embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a top view showing an example of the configuration of a laser irradiation device 200 according to an embodiment of the present invention. Figure 2 is a side view showing an example of the configuration of a laser irradiation device 200 according to an embodiment of the present invention.

[0015] 1, the laser irradiation device 200 includes an irradiation unit 10 that irradiates the substrate 1 transported to the irradiation area Ar with laser light L, a detection unit 300 that detects the timing of entry of the substrate 1 into the irradiation area Ar, and a control unit 6 that controls the irradiation of the laser light L by the irradiation unit 10. The laser irradiation device 200 forms a pattern on the surface of the substrate 1 with the laser light L irradiated from the irradiation unit 10.

[0016] Here, if a pattern is formed on the surface of the substrate 1 by the laser light L at a timing according to a detection signal of the substrate 1 by the detection unit 300, if there is variation in the pitch of the substrates 1 being transported to the irradiation area Ar, there is a possibility that the pattern will not be properly formed on the substrate 1. Note that the pitch of the substrates 1 means the interval in the transport direction between the multiple substrates 1 being transported.

[0017] In the laser irradiation device 200 according to an embodiment of the present invention, the control unit 6 determines the start position of irradiation of the laser light L by the irradiation unit 10 onto the substrate 1 entering the irradiation area Ar, based on the entry timing detected by the detection unit 300. This allows the irradiation of the laser light L onto the substrate 1 to begin from a position shifted in accordance with the variation in the pitch of the substrate 1, even if there is variation in the pitch of the substrate 1 being conveyed into the irradiation area Ar. This allows the pattern to be properly formed on the substrate 1. "Properly forming a pattern on the substrate 1" refers to, for example, "forming the entire desired pattern on the substrate 1" or "forming an accurate pattern on the substrate 1." Furthermore, even if there is variation in the substrate conveyance pitch, narrowing the substrate spacing, it is possible to avoid the problem of being unable to print on one of the substrates, resulting in a highly productive laser irradiation device that can stably laser print display patterns onto each substrate.

[0018] Furthermore, in the laser irradiation device 200, the irradiation unit 10 starts irradiation at a timing different from the irradiation reference start position when the substrates are transported at a timing different from the reference irradiation start position. As a result, similar to the above, even if there is variation in the pitch of the substrates 1 transported to the irradiation area Ar, it is possible to properly form a pattern on the substrate 1. Furthermore, even if there is variation in the transport pitch of the substrates and the substrate spacing becomes narrow, it is possible to avoid the problem of being unable to print on one of the substrates, and a highly productive laser irradiation device can be achieved that can stably laser print display patterns on each substrate.

[0019] Furthermore, in the laser irradiation device 200, the control unit 6 determines at least one of the irradiation start timing and the irradiation start position of the laser light L based on a converted distance converted from the time difference between the irradiation reference pulse and the detection signal indicating the entry timing output from the detection unit 300. As a result, as with the above, even if there is variation in the pitch of the substrates 1 transported to the irradiation area Ar, it is possible to properly form a pattern on the substrate 1. Furthermore, even if there is variation in the substrate transport pitch and the substrate spacing becomes narrow, it is possible to avoid the problem of being unable to print on one of the substrates, and a highly productive laser irradiation device can be achieved that can stably laser print display patterns on each substrate.

[0020] Furthermore, in the laser irradiation device 200, when the detection signal indicating the entry timing output from the detection unit 300 is earlier than the irradiation reference pulse, at least one of the irradiation start timing and irradiation start position of the laser light L is determined based on the converted distance converted from the time difference. As a result, as with the above, even when there is variation in the pitch of the substrates 1 transported to the irradiation area Ar, it is possible to properly form a pattern on the substrate 1. Even when there is variation in the substrate transport pitch and the substrate spacing becomes narrow, it is possible to avoid the problem of not being able to print on one of the substrates, and a highly productive laser irradiation device can be achieved that can stably laser print display patterns on each substrate.

[0021] The laser irradiation device 200 according to the embodiment of the present invention will be described in detail below.

[0022] (Irradiation unit 10) In the example shown in FIG. 1, the irradiation unit 10 includes a pulsed laser oscillator 21, a beam expander 22, a galvanometer mirror 221, a galvanometer mirror 222, and an fθ lens 241. The pulsed laser oscillator 21 irradiates laser light L by repeatedly flashing at short time intervals. The irradiation unit 10 may include a continuous wave laser (CW laser) instead of the pulsed laser oscillator 21. A continuous wave laser is a laser light source that continuously oscillates laser light. Regardless of the type of laser light source, the substrate 1 can be thermally deformed by irradiating the surface or interior of the substrate 1 with laser light L. As a result, a pattern is formed on the substrate 1. In this specification, an example using a pulsed laser light will be described.

[0023] The irradiation unit 10 irradiates the surface of the substrate 1 being transported in the direction of arrow A with laser light L from a pulse laser oscillator 21. Furthermore, the irradiation unit 10 may change the state of the surface of the substrate 1 by irradiating it with laser light L, or may change the inside of the substrate 1.

[0024] The pulsed laser oscillator 21 is a light source that emits laser light L. The pulsed laser oscillator 21 emits a substantially parallel pulsed laser beam in the positive direction of the Y axis. As an example, the pulsed laser oscillator 21 shown in FIG. 1 can switch between and emit laser light of three oscillation wavelengths: a fundamental wave with an oscillation peak wavelength of 1064 nanometers, a second harmonic with an oscillation peak wavelength of 532 nanometers, and a third harmonic with an oscillation peak wavelength of 355 nanometers.

[0025] At any oscillation peak wavelength, the pulse width of the laser light L is 15 picoseconds or less. The repetition frequency of the laser light L can be appropriately selected within a range from a single shot to 200 kHz. The beam diameter of the laser light L is approximately 2.0 mm for the fundamental wave, approximately 1.4 mm for the second harmonic, and approximately 1.3 mm for the third harmonic.

[0026] For example, a fiber laser-based Talisker Ultra355-4 manufactured by Coherent Corporation can be applied to the pulse laser oscillator 21. However, the present invention is not limited to this, and other pulse lasers can also be used.

[0027] The pulsed laser oscillator 21 can be switched between emission (ON) and non-emission (OFF) based on the pattern data of the pattern to be formed on the substrate 1.

[0028] The beam expander 22 is disposed on the positive Y-axis side of the pulsed laser oscillator 21. The beam expander 22 expands the beam diameter of the laser light L emitted by the pulsed laser oscillator 21 by a predetermined expansion factor, and emits a substantially parallel laser beam on the positive Y-axis side.

[0029] The detection unit 300 is disposed upstream of the substrate 1 being transported in the direction of arrow A. The detection unit 300 includes a transport detection light emitting element 301 and a transport detection light receiving element 302. The detection unit 300 detects the timing when the substrate 1 blocks the light irradiated by the transport detection light emitting element 301 toward the transport detection light receiving element 302. The laser irradiation device 200 detects the timing when the transported substrate 1 enters the irradiation position of the laser light L based on this light blocking timing and information about the distance between the irradiation position of the laser light L and the detection unit 300, and determines the start position of pattern formation in the direction of arrow A.

[0030] The galvanometer mirror 221, the galvanometer mirror 222, and the fθ lens 241 scan the laser light L emitted from the pulse laser oscillator 21. However, the irradiation unit 10 may use a polygon mirror instead of the galvanometer mirror. Also, the irradiation unit 10 does not necessarily have to include the fθ lens 241.

[0031] The galvanometer mirror 221 is disposed on the Y-axis positive side of the beam expander 22. The galvanometer mirror 221 deflects the laser light, the beam diameter of which has been expanded by the beam expander 22, toward the Z-axis positive side. The galvanometer mirror 221 is driven by a motor to swing in the direction of arrow B, thereby scanning the laser light L from the beam expander 22 in the direction of arrow A.

[0032] The direction of arrow A is the direction in which the galvanometer mirror 221 scans the laser light L and also the direction in which the substrate 1 is transported. Therefore, the control of the scanning in the direction of arrow A by the galvanometer mirror 221 needs to be determined taking into consideration the transport speed at which the substrate 1 is transported in the direction of arrow A.

[0033] Galvanometer mirror 222 is disposed on the negative Z-axis side of galvanometer mirror 221. Galvanometer mirror 222 scans the laser light incident from galvanometer mirror 221 in the direction of arrow C in the side view of FIG.

[0034] The fθ lens 241 irradiates the substrate 1 with the laser light L from the galvanometer mirror 222. The fθ lens 241 is designed and manufactured so that the scanning speed of the laser light L that passes through the peripheral and central parts of the fθ lens 241 is approximately constant. The fθ lens 241 is also designed and manufactured so as to collect and focus the laser light L over the entire surface of the substrate 1 that is to be irradiated with the laser light L. The fθ lens 241 may be configured with a single lens, or the function of the fθ lens 241 may be realized by combining multiple lenses, or the function of the fθ lens 241 may be realized by a configuration including optical elements other than lenses, such as mirrors.

[0035] The laser irradiation device 200 places the substrate 1 on the Y-axis positive side of the fθ lens 241, and irradiates the laser light L onto the surface 400 of the substrate 1 that faces the fθ lens 241.

[0036] (Detection unit 300) The detection unit 300 is disposed upstream in the direction of arrow A. The detection unit 300 includes a transport detection light emitting element 301 and a transport detection light receiving element 302. The transport detection light emitting element 301 detects the timing when the substrate 1 blocks light irradiated toward the transport detection light receiving element 302. The laser irradiation device 200 detects the timing when the substrate 1 being transported enters the irradiation area Ar of the laser light Ll based on this light blocking timing and information about the distance between the irradiation position of the laser light L and the detection unit 300, and determines the start position of pattern formation in the transport direction of the substrate 1.

[0037] Furthermore, the laser irradiation device 200 can sequentially irradiate laser light onto each of a plurality of substrates 1 that are sequentially transported by a transport unit such as a belt conveyor. In this way, a pattern is formed on the surface 400 of the substrate 1.

[0038] (Control unit 6) The control unit 6 controls the laser irradiation device 200. Specifically, the control unit 6 is responsible for various software-related controls. In this embodiment, the control unit 6 determines the irradiation start position of the laser light L by the irradiation unit 10 onto the base material 1 entering the irradiation area Ar, in accordance with the entry timing detected by the detection unit 300.

[0039] (Synchronization detection unit) A synchronous detection unit is provided near the galvanometer mirror 222. The synchronous detection unit includes a synchronous detection LD (Laser Diode) and a synchronous detection PD (Photo Diode). The synchronous detection LD emits laser light toward the galvanometer mirror 222, and the synchronous detection PD receives the light reflected by the galvanometer mirror 222. The laser irradiation device 200 determines the start timing of pattern formation in the intersecting direction based on the light receiving signal of the synchronous detection PD.

[0040] The laser irradiation device 200 is triggered by the start timing of pattern formation in each of the direction in which the substrate 1 is transported and the intersecting direction, and irradiates the substrate 1, which is being transported at high speed, with laser light L extending in the direction of arrow C while controlling the on / off of the pulse laser oscillator 21 based on pattern data.

[0041] <Pitch division of base material 1> Next, the pitch division of the substrate 1 in the laser irradiation device 200 will be described with reference to Fig. 3 to Fig. 5. Fig. 3 is a diagram illustrating a pitch division device 500 for the substrate 1. Fig. 4 is a diagram showing an example of pitch division variation. Fig. 5 is a diagram showing an example of a deviation between an ideal pulse for the pitch division of the substrate 1 and a detection signal by the detection unit 300.

[0042] In order to form a pattern by irradiating laser light L onto the substrates 1 that are transported in large quantities to the irradiation area Ar, a pitch division device 500 for the substrates 1 is used, which performs pitch division by arranging each of the multiple substrates 1 at approximately equal intervals and transporting them by a transport section.

[0043] 3, the pitched substrate 1 is detected as entering the irradiation area Ar by a sensor installed just before the irradiation area Ar in the conveying direction of the substrate 1, and is irradiated with laser light L within the scanning range Sr. Here, the distance LSL is the distance from the detection unit 300 to the reference position for starting irradiation of the laser light L. Furthermore, the time tSL is the time from the detection unit 300 to the start of irradiation of the laser light L. In other words, when the conveying speed is v, the time tSL is expressed as LSL / v.

[0044] FIG. 4 shows the range of pitch error when the pitch between substrates 1 is 90 mm. In this embodiment, an apparatus with a productivity of 1000 bpm (transporting 1000 bottles per minute) is described. However, this value and the belt conveyor speed vary depending on the apparatus and are not intended to limit the invention. The conveying device (belt conveyor) moves at a substantially constant speed of 1500 mm / s, and the bottle breaking device supplies bottles to the belt conveyor one by one at intervals equivalent to 1000 bpm, i.e., every 60 ms. Bottles are arranged on the belt conveyor at approximately 90 mm intervals, but arranging them accurately is difficult, and as shown in FIG. 4, some variation occurs. In FIG. 4, it has been confirmed that in the laser irradiation device 200 according to this embodiment, the deviation from the ideal center position of the substrate 1 does not exceed ±9 mm when transporting 1000 substrates 1. This maximum deviation, particularly the maximum deviation ahead of schedule, is an important factor in this embodiment, as will be discussed later.

[0045] When pitch variations occur in the substrate 1 shown in FIG. 4, a variation ±Δt similar to clock jitter occurs between the ideal pulse (here, the period is 60 ms) of the pitch distribution of the substrate 1 and the detection signal of the detection unit 300, as shown in FIG. 5. This 2 × Δt is called period jitter. For example, the maximum jitter is ±6 ms, which is 12 ms. Furthermore, the ideal pulse of the pitch distribution of the substrate 1 here becomes the reference pulse for irradiating the laser light L.

[0046] <Operation of the laser irradiation device 200> Fig. 6 is a flowchart showing a first example of the operation of the laser irradiation device 200. Fig. 6 shows the operation of the laser irradiation device 200 when the ideal pulse for the pitch division of the substrate 1 is set to 60 ms, which is used as the irradiation reference pulse.

[0047] In the operation according to the first example, when there is no timing deviation in the conveyance of the substrate 1, the laser irradiation device 200 irradiates the laser light L at the irradiation reference start position in response to a detection signal of the substrate 1 from the detection unit 300. When there is a timing deviation in the conveyance of the substrate 1, the operation is as shown in the following flow chart.

[0048] First, in step S11, the laser irradiation device 200 waits for a detection signal of the substrate 1 by the detection unit 300 for the first line at the start.

[0049] Subsequently, in step S12, the laser irradiation device 200 determines whether or not the base material 1 is entering the irradiation area Ar using the control unit 6. If it is determined in step S12 that the base material 1 is not entering (step S12, NO), the laser irradiation device 200 performs the operation of step S11 again. On the other hand, if it is determined in step S12 that the base material 1 is entering (step S12, YES), the laser irradiation device 200 starts a timer that generates an irradiation reference pulse every 60 ms in step S13, and starts irradiating the laser light tSL after the start of the irradiation reference pulse.

[0050] Next, the operation of the second and subsequent continuous flows from step S14 onwards will be described. In step S14, the laser irradiation device 200 determines, via the control unit 6, whether the detection signal for the next substrate is early (CASE: A) or whether the 60 ms timer is early (CASE: B).

[0051] In step S14, if it is determined that the detection signal of the next substrate is earlier (step S14, CASE: A), in step S17, the laser irradiation device 200 shifts the position downstream by Δd from the irradiation position (irradiation reference start position) after tSL from the 60 ms timer and starts irradiating the laser light L.

[0052] Subsequently, in step S18, the laser irradiation device 200 starts the timer again after the irradiation reference pulse of 60 ms has ended.

[0053] Subsequently, in step S19, the laser irradiation device 200 determines whether or not to end the operation through the control unit 6. If it is determined not to end the operation in step S19 (step S19, NO), the laser irradiation device 200 performs the operations from step S14 onwards again, and repeats these operations until it is determined to end the operation in step S19. On the other hand, if it is determined to end the operation in step S19 (step S19, YES), the laser irradiation device 200 ends the operation.

[0054] On the other hand, in step S14, if it is determined that the 60 ms timer is early (step S14, CASE: B), in step S15, the laser irradiation device 200 irradiates the laser light L from the irradiation section 10 after tSL has elapsed after the detection signal of the substrate 1 is generated (at the irradiation reference start position).

[0055] Subsequently, in step S16, the laser irradiation device 200 starts the timer again at the same time as receiving a detection signal of the next substrate 1 by the irradiation reference pulse. Thereafter, the laser irradiation device 200 proceeds to step S19.

[0056] By the above operation, in the first example, the laser light L can be irradiated without any problem even when the substrate 1 is transported to the irradiation area Ar at a time shorter than the 60 ms irradiation reference pulse cycle. There is no problem even when the substrate 1 is transported continuously at short intervals, and it is also possible to deal with a case where the substrate 1 is not transported due to some kind of trouble, which is called a missing part. In other words, the laser irradiation device 200 can properly form a pattern even when there is a variation in the pitch of the substrate 1. "Properly forming a pattern" means forming the entire desired pattern on the substrate 1 without any missing parts.

[0057] 7, the operation of the laser irradiation device 200 according to the first example will be described using a timing diagram showing the relationship between the detection signal of the substrate 1 by the detection unit 300, the irradiation reference pulse, and the irradiation signal. Fig. 7 is a diagram showing an example of the relationship between the detection signal of the substrate 1 by the detection unit 300, the irradiation reference pulse, and the irradiation signal. The irradiation reference pulse is set to 60 ms.

[0058] First, it is assumed that the pitch of the substrate 1 varies within ±9 mm, and therefore the average period of the detection signal of the substrate 1 by the detection unit 300 will have edge variations (jitter) just like the pitch of the substrate 1. It is also assumed that there will be occasional missing teeth.

[0059] A delay of tSL occurs from when the substrate 1 passes the position of the detection unit 300 and a detection signal is generated by the detection unit 300 until irradiation is actually performed on the substrate 1. In this embodiment, tSL is fixed regardless of variations.

[0060] Here, set up the following two cases and run them. CASE (A): If substrate 1 is faster than the 60 ms timer, it restarts after the irradiation reference pulse 60 ms. CASE (B): If the substrate 1 is slower than 60 ms, restart is performed at the timing of the detection signal from the detection unit 300.

[0061] In the case of CASE (A), Δt is converted into a distance variable Δx shown in the formula below, and the irradiation start position is determined by shifting it by Δx downstream from the irradiation reference start position. Note that Vave in the formula below means the average conveyance speed. Δx=Δt×Vave

[0062] That is, Δt2 in Figure 7 is converted to a distance Δx2, and Δt3 is converted to a distance Δx3, and irradiation is performed by shifting the position downstream from the reference irradiation start position. Here, the pitch division of the substrate 1 is assumed to vary within ±9 mm, so Δt is assumed to be no more than 12 ms. If the substrate 1 is slower than 60 ms or if there are gaps, irradiation is performed simply by waiting for the reference irradiation start timing, so it is possible to deal with problems such as gaps.

[0063] So far, the operation has been explained when the ideal pulse for pitching the substrate 1 is set to 60 ms and the irradiation reference pulse is also set to 60 ms. Here, the effect of shortening the irradiation reference pulse to 59 ms when the period of the conveyance pitch of the substrate 1 is 60 ms will be described.

[0064] The pitch timing period of the substrate 1 has an error of about ±0.1%. If the irradiation reference pulse is set to 60 ms, and the pitch timing period of the substrate 1 is smaller than 60 ms by the amount of error, the error will accumulate with each writing, and will eventually exceed the irradiation range of the laser light L. In such a case, the laser irradiation device 200 can solve the problem of error accumulation by setting the irradiation reference pulse to a time shorter than the pitch timing period of the substrate 1.

[0065] As another effect, even if the substrate 1 is continuously transported at a timing earlier than the reference position for starting the scanning of the laser light L, the laser irradiation device 200 delays the timing of the next substrate 1 by 1 ms for each cycle of the irradiation reference pulse, and gradually returns to the reference position for starting the scanning of the laser light L.

[0066] The period of the irradiation reference pulse is set taking into consideration the error specification of the conveyance pitch period of the substrate 1, and is preferably set to, for example, at least 0.1% shorter than 60 ms, that is, to a value of 59.94 ms or less. Furthermore, considering the effect of gradually returning to the reference start position of the laser beam scanning, it is even more preferable to set the irradiation reference pulse shorter than the conveyance pitch period of the substrate 1 so that even if it shifts to the maximum end of 18 mm, which is the allowance, it will return to the reference position in several to ten times.

[0067] That is, in the laser irradiation device 200, the irradiation reference pulse is set to a time, for example, 59 ms, that is shorter than the pitch timing period of the substrate 1. This solves the problem that the accumulation of errors due to errors in the pitch timing period of the substrate 1 eventually exceeds the irradiation range of the laser light L. As another effect, even if the substrate 1 is continuously transported at a timing earlier than the reference start position for scanning with the laser light L, the laser irradiation device 200 has the effect of delaying the timing of the next substrate 1 by 1 ms for each cycle of the irradiation reference pulse, gradually returning it to the reference start position for scanning with the laser light L. Furthermore, even if there is variation in the pitch of the substrate 1 transported to the irradiation area Ar, the irradiation start position of the irradiation unit 10 with the laser light L on the substrate 1 entering the irradiation area Ar can be accurately determined so that the variation in the pitch of the substrate 1 is corrected.

[0068] The irradiation reference pulse can be made shorter by increasing the irradiation speed, but there are limits to this due to various restrictions on irradiation, and it is difficult to significantly shorten the irradiation time when transporting at the limit of productivity. In other words, this embodiment is very effective even with an irradiation reference pulse of about 59 ms compared to 60 ms. The setting range of the irradiation reference pulse is expressed by the following equation (1). Irradiation time < timer period of irradiation reference pulse < conveyance pitch period of substrate 1 - error value... Equation (1)

[0069] Furthermore, by determining the setting range of the irradiation reference pulse according to equation (1), it is possible to solve the problem that the accumulation of errors due to errors in the pitch division period of the substrate 1 eventually exceeds the irradiation range of the laser light L, and it is possible to properly form a pattern on the substrate 1.

[0070] Figure 8 is an image diagram explaining the setting range of the irradiation reference pulse expressed by formula (1). The jump time in Figure 8 means the time it takes for irradiation of the laser light L to jump to the next substrate 1 after irradiation of the laser light L to the substrate 1 ends. In this way, the present invention minimizes the pitch between substrates to the utmost limit, maximizing productivity and providing a significant effect on stable printing operations.

[0071] Fig. 9 is a flowchart showing a second example of the operation of the laser irradiation device 200. Fig. 9 shows the operation of the laser irradiation device 200 when the ideal pulse for pitching the substrate 1 is 60 ms and the irradiation reference pulse is 59 ms. The operation of the second example differs from the operation of the first example shown in Fig. 6 in that the timer is 59 ms and the timer in step S27 is also 59 ms.

[0072] In the second example, when there is no timing deviation in the transport of the substrate 1, the laser irradiation device 200 irradiates the laser light L at the irradiation reference start position in response to the detection signal of the substrate 1 from the detection unit 300. On the other hand, when there is a timing deviation in the transport of the substrate 1, the operation shown in the following flow is performed. Furthermore, when there is a timing deviation in the transport of the substrate 1, the operation shown in the following flow is performed. When the output of the detection unit 300 is earlier than the irradiation reference pulse 59 ms timer, the laser irradiation device 200 shifts the irradiation position by the amount of the earlier transport timing, tSL after the irradiation reference pulse, and irradiates the laser light L. This earlier transport timing is defined as Δt, and Δt converted into a positional deviation is defined as Δd.

[0073] Basically, the operation is almost the same as that shown in FIG. 6, and from the second substrate 1 onwards, the operation proceeds as follows. (1) Case A is when the detection signal of the substrate 1 by the detection unit 300 is detected in a time shorter than the 59 ms period of the irradiation reference pulse, and Case B is when the detection signal of the substrate 1 by the detection unit 300 is detected in a time longer than the 59 ms period of the irradiation reference pulse. (2) In the case of CASE: A, in step S17, the laser irradiation device 200 shifts the position downstream by Δd from the irradiation position tSL after the 60 ms timer (this is the irradiation reference start position) and starts irradiating the laser light L, and starts the 59 ms timer again after the irradiation reference pulse of 59 ms has ended. (3) In the case of CASE: B, irradiation of the laser light L begins tSL after the detection signal of the substrate 1 is generated by the detection unit 300. The irradiation reference pulse starts the 59 ms timer again at the same time as receiving the next detection signal of the substrate 1 by the detection unit 300.

[0074] By the above operation, in the second example, the laser light L can be irradiated without any problem even when the substrate 1 is transported to the irradiation area Ar at a time shorter than the 59 ms irradiation reference pulse cycle. There is no problem even when the substrate 1 is transported continuously at short intervals, and it is also possible to deal with a case where the substrate 1 is not transported due to some kind of trouble, which is called a missing part. In other words, the laser irradiation device 200 can properly form a pattern even when there is variation in the pitch of the substrate 1.

[0075] 10, the operation of the laser irradiation device 200 according to the second example will be described using a timing diagram showing the relationship between the detection signal of the substrate 1 by the detection unit 300, the irradiation reference pulse, and the irradiation signal. Fig. 10 is a diagram showing an example of the relationship between the detection signal of the substrate 1 by the detection unit 300, the irradiation reference pulse, and the irradiation signal. In Fig. 10, when the ideal pulse for the pitch division of the substrate 1 is 60 ms, the irradiation reference pulse is set to 59 ms.

[0076] First, it is assumed that the pitch of the substrate 1 varies within ±9 mm, and therefore the average period of the detection signal of the substrate 1 by the detection unit 300 will have edge variations (jitter) just like the pitch of the substrate 1. It is also assumed that there will be occasional missing teeth.

[0077] A delay of tSL occurs from when the substrate 1 passes the position of the detection unit 300 and a detection signal is generated by the detection unit 300 until irradiation is actually performed on the substrate 1. In this embodiment, tSL is fixed regardless of variations.

[0078] Here, set up the following two cases and run them. CASE (A): If substrate 1 is faster than the 59 ms timer, it restarts after the irradiation reference pulse 59 ms. CASE (B): If the substrate 1 is slower than 59 ms, restart is performed at the timing of the detection signal from the detection unit 300.

[0079] In the case of CASE (A), Δt is converted into a distance variable Δx shown in the following formula, and the irradiation start position is determined by shifting it by Δx downstream from the irradiation reference start position. In the formula below, Vave means the average conveying speed. Δx=Δt×Vave

[0080] That is, Δt2 in Figure 10 is converted to a distance Δx2, and Δt3 is converted to a distance Δx3, and irradiation is performed by shifting the position downstream from the reference irradiation start position. Here, the pitch division of the substrate 1 is assumed to vary within ±9 mm, so Δt is assumed to be no more than 18 ms. If the substrate 1 is slower than 60 ms or if there is a gap in the timing, irradiation is simply performed by waiting for the reference irradiation start timing, so it is possible to deal with problems such as gaps in the timing.

[0081] If the period of the transport pitch of the substrate 1 is 60 ms and the irradiation reference pulse is 59 ms, even if the substrate 1 is continuously transported at a timing earlier than the reference position for starting the scanning of the laser light L, the laser irradiation device 200 delays the timing of the next substrate 1 by 1 ms for each period of the irradiation reference pulse (in this example, 1 ms corresponds to 1.5 mm), thereby gradually returning the substrate 1 to the reference position for starting the scanning of the laser light L.

[0082] Furthermore, the pitch timing period of the substrate 1 has an error of about ±0.1%, and if the irradiation reference pulse is 60 ms, and the pitch timing period of the substrate 1 is smaller than 60 ms by the error amount, the error accumulates with each writing, and may eventually exceed the irradiation range of the laser light L. In this case, too, the problem of error accumulation can be solved by setting the irradiation reference pulse to a time shorter than the pitch timing period of the substrate 1 in the laser irradiation device 200.

[0083] <Modification> Next, a modified example will be described with reference to Fig. 11, in which patterns are formed in parallel or continuously on a plurality of substrates 1 by a plurality of irradiation units 10. Fig. 11 is a diagram showing an example of the configuration of a laser irradiation device 200 according to the modified example.

[0084] In the example shown in FIG. 11, the laser irradiation device 200 differs from the laser irradiation device 200 according to the first embodiment of the present invention mainly in that it has four irradiation units 10, namely, irradiation unit 10-1, irradiation unit 10-2, irradiation unit 10-3 and irradiation unit 10-4, and four detection units 300, namely, detection unit 300-1, detection unit 300-2, detection unit 300-3 and detection unit 300-4.

[0085] The four irradiation units 10 and the four detection units 300 are in one-to-one correspondence. The laser irradiation device 200 irradiates laser light L from each of the four irradiation units 10 in response to a detection signal of the substrate 1 by the corresponding detection unit 300. Each of the four irradiation units 10 irradiates laser light L onto the corresponding four substrates 1.

[0086] One irradiation unit 10 irradiates every third substrate 1 of the multiple substrates 1 being conveyed with laser light L as the corresponding substrate 1. In FIG. 11, "for 1" represents a substrate 1 irradiated with laser light L by irradiation unit 10-1. "for 2" represents a substrate 1 irradiated with laser light L by irradiation unit 10-2. "for 3" represents a substrate 1 irradiated with laser light L by irradiation unit 10-3. "for 4" represents a substrate 1 irradiated with laser light L by irradiation unit 10-4.

[0087] In the example shown in FIG. 11, while the laser light L is being irradiated onto the substrate 1 for "1" by the irradiation unit 10-1, the substrates 1 for "2" to "4" pass by. That is, the operation algorithm for irradiating the substrate 1 with the laser light L using n irradiation units 10 is as shown in FIG. 12. Here, FIG. 12 is an image diagram showing an example of the operation algorithm for irradiating the substrate 1 with the laser light L using n irradiation units 10. In FIG. 12, the period for irradiating one substrate 1 with the laser light L is 60×nms. If an irradiation reference pulse is 1 ms shorter, the period is (60×n-1) ms.

[0088] <Pattern formed on substrate 1> 13 is a diagram showing an example of a pattern 401 formed on a surface 400 of the substrate 1. Lx indicates the length of a target area on the substrate 1 to be irradiated with the laser light L in the direction in which the substrate 1 is transported (the direction of arrow A). Furthermore, Lz indicates the length of the target area in the direction perpendicular to the direction in which the substrate 1 is transported (the direction of arrow C).

[0089] (Productivity of pattern formation by laser irradiation device 200) Laser light L is irradiated onto the surface or inside of the substrate 1, thereby forming a pattern through thermal deformation of the substrate 1. When pulsed laser light L is used, the productivity of pattern formation depends on the repetition frequency of the emission of the laser light L, because the laser repeatedly flashes at short time intervals.

[0090] Here, if the size of the substrate 1 is W (mm), the distance between multiple substrates 1 in the substrate 1 transport direction is d (mm), and the productivity of pattern formation is X (pieces / min), the transport speed V (mm / s) of the substrate 1 is calculated using the following formula. Note that the distance between multiple substrates 1 in the transport direction is equal to the distance between multiple substrates 1 in the transport direction.

number

[0091] Furthermore, if the pixel density is a (dpi), the time T allowed per scan by the galvanometer mirror 222 to ensure productivity X is calculated using the following formula (inches are converted to mm):

number

[0092] Furthermore, if the pattern formation area in the intersecting direction is Lz (mm), the time Δt (s) allowed per dot in the intersecting direction to ensure productivity X is calculated using the following formula:

number

[0093] Next, we will explain the fluence of the laser light. The fluence F of the laser light can be expressed as follows: P=E·ν F=E / S

[0094] P (W) represents the average output (light intensity) of the pulsed laser oscillator 21, E (J) represents the pulse energy per pulse of the laser light, and ν (Hz) represents the repetition frequency of the laser light emitted by the pulsed laser oscillator 21. F (J / cm 2 ) represents the fluence, and S (cm 2 ) represents the area of ​​the laser beam spot.

[0095] The fluence F corresponds to the value obtained by dividing the pulse energy by the area of ​​the laser beam spot. The fluence at the substrate constituting the substrate 1 is the value obtained by dividing the pulse energy of the laser light emitted from the pulse laser oscillator 21 by the area of ​​the laser beam spot on the substrate constituting the substrate 1.

[0096] When the laser light L has a pulse width on the nanosecond scale, the laser irradiation device 200 forms a pattern by thermal denaturation according to the absorption spectrum of the substrate 1. On the other hand, when the laser light L has a pulse width on the picosecond scale, the laser irradiation device 200 forms a pattern by thermal denaturation according to both the absorption spectrum and multiphoton absorption.

[0097] Multiphoton absorption is a nonlinear phenomenon in which, when irradiated with laser light, a material is excited by light with a wavelength corresponding to 1 / 2 or 1 / 3 of the laser light's oscillation wavelength, and multiple photons are absorbed, causing the state of electrons and atoms to transition to a higher energy level. Using laser light with a pulse width on the picosecond scale, it is possible to sublimate a substrate from a solid state without passing through a molten state, and form processing marks on the substrate.

[0098] When a pulse laser oscillator 21 is selected in which the fluence required to irradiate the substrate 1 with laser light is such that one dot pattern can be formed with one pulse, the pattern formation frequency is the repetition frequency ν (Hz).

[0099] On the other hand, if the fluence of the pulsed laser oscillator 21 is small and N pulses are required to form a pattern of one dot, the pattern formation frequency is v / N (Hz), and the time required to form a pattern of one dot is N / v [s]. In this case, only values ​​greater than N / v (s) are allowed for Δt, and the substrate 1 cannot be transported at a speed faster than the speed allowed for pattern formation by one scan. In other words, the time allowed for pattern formation of one dot becomes the rate-limiting factor for productivity.

[0100] When irradiating the substrate 1 with the laser light L such that the above relationship holds, for example, when forming a pattern having a horizontal width of 40 mm, if the resolution of the vertical irradiation of the laser light L is 300 (dpi), the pitch of each line will be as shown in the following formula, and 476 lines will be formed within 40 mm. 25.4 / 300=0.084(mm)

[0101] Since 476 lines are formed within a movement distance of 108 mm of the substrate 1 per line during pattern formation, it can be seen that one line must be written while the substrate 1 moves 0.22 mm.

[0102] The scanning control and irradiation control of the laser light L in the laser irradiation device 200 are controlled by the control unit 6. The hardware configuration and functional configuration of the control unit 6 will be described.

[0103] <Hardware configuration of control unit 6> 14 is a block diagram showing an example of the hardware configuration of the control unit 6. It is not necessary to provide all of the hardware and functional components that make up the control unit 6. Depending on the form in which the laser irradiation device 200 is used, some hardware and functional components may not be provided. Furthermore, all of the hardware and functional components of the control unit 6 may be provided in the laser irradiation device 200, or some of the hardware and functional components may be connected to the outside of the laser irradiation device 200. Furthermore, the control unit 6 may be connected to the outside of the laser irradiation device 200.

[0104] The control unit 6 is configured as a computer or a computer-like configuration. The control unit 6 includes a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, a RAM (Random Access Memory) 503, a HD (Hard Disk) 504, a HDD (Hard Disk Drive) controller 505, and a display 506. The control unit 6 also includes an external device connection I / F (Interface) 508, a network I / F 509, a bus line 510, a keyboard 511, a pointing device 512, a DVD-RW (Digital Versatile Disk Rewritable) drive 514, and a media I / F 516.

[0105] The CPU 501 is a processor that controls the overall operation of the control unit 6. The ROM 502 is a memory that stores programs used to drive the CPU 501, such as an IPL (Initial Program Loader).

[0106] The RAM 503 is a memory used as a work area for the CPU 501. The HD 504 is a memory that stores various data such as programs. The HDD controller 505 controls reading and writing of various data from and to the HD 504 under the control of the CPU 501.

[0107] The display 506 displays various types of information such as a cursor, menu, window, text, or image. The external device connection I / F 508 is an interface for connecting various types of external devices. In this case, the external devices are the pulse laser oscillator 21, the scanning unit 23, the synchronization detection unit 25, etc. However, other devices such as a USB (Universal Serial Bus) memory or a printer can also be connected.

[0108] The network I / F 509 is an interface for data communication using a communication network. The bus line 510 is an address bus, a data bus, etc. for electrically connecting the components such as the CPU 501.

[0109] The keyboard 511 is a type of input means having multiple keys for inputting characters, numbers, various instructions, etc. The pointing device 512 is a type of input means for selecting and executing various instructions, selecting a processing target, moving a cursor, etc.

[0110] A DVD-RW drive 514 controls reading and writing of various data from and to a DVD-RW 513, which is an example of a removable recording medium. Note that the storage medium is not limited to a DVD-RW. A media I / F 516 controls reading and writing (storing) of data from and to a recording medium 515, such as a flash memory.

[0111] It is not necessary to provide all of these pieces of hardware that constitute the control unit 6. Depending on the mode in which the laser irradiation device 200 is used, some hardware may not be provided.

[0112] <Functional configuration of control unit 6> 15 is a block diagram showing an example of the functional configuration of the control unit 6. The control unit 6 includes an irradiation data input unit 61, a profile data designation unit 62, a storage unit 63, a control data generation unit 64, a laser irradiation control unit 65, a laser scanning control unit 66, a 59 ms timer unit 67, an irradiation start position correction amount calculation unit 68, and a delay unit 69. The scanning unit 23 is composed of the galvanometer mirror 221, the galvanometer mirror 222, the fθ lens 241, etc. shown in FIG. 1. The synchronization detection unit 25 detects synchronization of the scanning of the laser light L by the scanning unit 23.

[0113] The functions of the control data generation unit 64, laser irradiation control unit 65, laser scanning control unit 66, 59 ms timer unit 67, irradiation start position correction amount calculation unit 68, and delay unit 69 are realized by the CPU 501 executing a predetermined program and outputting a control signal via the external device connection I / F 508, etc. However, electronic or electric circuits such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array) may be added to the hardware configuration of the control unit 6, and some or all of the functions of each component may be realized by the electronic or electric circuit. The function of the storage unit 63 is realized by the HD 504, etc.

[0114] The irradiation data input unit 61 inputs irradiation data for irradiating the surface 400 of the substrate 1 from an external device such as a PC (Personal Computer) or a scanner. The irradiation data may be something other than an irradiation pattern. It may also be information indicating a predetermined code such as a barcode or QR code (registered trademark), or a pattern of characters, figures, photographs, etc., corresponding to the irradiation pattern.

[0115] However, the irradiation pattern data is not limited to data input from an external device. The user of the laser irradiation device 200 can also input generated irradiation pattern data using the keyboard 511 or pointing device 512 of the control unit 6.

[0116] The irradiation data input unit 61 outputs the input irradiation data to each of the control data generation unit 64 and the profile data designation unit 62. The irradiation data input from the irradiation data input unit 61 may be temporarily stored in the storage unit 63. Since the irradiation data differs depending on the shape of the substrate 1, etc., irradiation data corresponding to the type of substrate 1 may be stored in advance in the storage unit 63 to improve convenience.

[0117] The profile data designation unit 62 designates profile data. The profile data here determines the irradiation area and non-irradiation area when irradiating while scanning with laser light, and also determines the acceleration, acceleration / deceleration period, and constant speed period when accelerating the scanning speed. The profile data is stored in the storage unit 63. The profile data may be stored in advance, or may be stored as a temporary storage means during scanning and irradiation.

[0118] The control data generation unit 64 generates control data based on the irradiation data from the irradiation data input unit 61 and the profile data from the profile data designation unit 62. In addition, the control data generation unit 64 outputs the generated control data to the laser irradiation control unit 65 and the laser scanning control unit 66.

[0119] The laser irradiation control unit 65 includes a light intensity control unit 651 and a pulse control unit 652, and controls the irradiation of the substrate 1 with the laser light L by the pulse laser oscillator 21 based on the irradiation condition data. The light intensity control unit 651 controls the light intensity of the processing laser beam 20, and the pulse control unit 652 controls the pulse width and irradiation timing of the processing laser beam 20.

[0120] The laser scanning control unit 66 controls the scanning unit 23 based on a synchronization detection signal from the synchronization detection unit 25. When the pulse laser oscillator 21 is configured with multiple pulse lasers, the laser irradiation control unit 65 controls each of the multiple pulse lasers independently. The laser scanning control unit 66 controls the scanning of the galvanometer mirror 221 and polygon mirror 231 by the scanning unit 23 based on scanning condition data. Specifically, it controls the on / off driving of the galvanometer mirror 221 and polygon mirror 231, controls the driving frequency, etc.

[0121] The 59 ms timer unit 67 generates a 59 ms irradiation reference pulse. The 59 ms timer unit 67 can measure time using the generated 59 ms irradiation reference pulse.

[0122] The irradiation start position correction amount calculation unit 68 determines the irradiation start position of the laser light L by the irradiation unit 10 onto the base material 1 entering the irradiation area Ar, according to the timing of entry of the base material 1 into the irradiation area Ar detected by the detection unit 300. When the irradiation start position is deviated from the ideal irradiation start position, the irradiation start position correction amount calculation unit 68 can determine the irradiation start position of the laser light L deviated from the ideal irradiation start position.

[0123] The delay unit 69 can delay the timing of the laser irradiation control unit 65 to irradiate the laser light L, etc.

[0124] <Detailed Operation of Laser Irradiation Device 200> FIG. 16 is a sequence chart showing an example of detailed operation of the laser irradiation device 200 when the irradiation reference timing is set to 59 ms.

[0125] First, in step S31, the laser irradiation device 200 notifies the control unit 6 by the detection unit 300 that the first substrate 1 has arrived.

[0126] Subsequently, in step S32, since the first substrate 1 always arrives at ideal timing, the laser irradiation device 200 notifies the irradiation unit 10 via the control unit 6 that the deviation of the irradiation start position is zero.

[0127] Subsequently, in step S33, the laser irradiation device 200 causes the control unit 6 to send a start trigger start_trg to the irradiation unit 10 with a time delay of 0 from the reference.

[0128] Subsequently, in step S34, the laser irradiation device 200 notifies the control unit 6 by the detection unit 300 that the Nth substrate 1 has arrived.

[0129] If the interval between the substrates 1 is less than 59 ms (defined as X (ms)), in step S35, the laser irradiation device 200 causes the control unit 6 to start the 59 ms timer unit 67 at the time point of 59 ms.

[0130] Subsequently, in step S36, the control unit 6 of the laser irradiation device 200 calculates the amount of movement of the start position downstream from the irradiation reference start position (Y=(59−X) / (average linear velocity)).

[0131] Subsequently, in step S37, the laser irradiation device 200 notifies the irradiation unit 10 via the control unit 6 to shift the irradiation start position downstream by Y (mm) in the conveyance direction of the substrate 1.

[0132] If the interval between the substrates 1 is 59 ms or more, in step S38, the laser irradiation device 200 notifies the irradiation unit 10 via the control unit 6 that the deviation of the irradiation start position from the irradiation reference start position is zero.

[0133] Subsequently, in step S39, the laser irradiation device 200 causes the control unit 6 to reset the 59 ms timer unit 67 and restart it.

[0134] Subsequently, in step S40, the laser irradiation device 200 causes the control unit 6 to send a start trigger start_trg to the irradiation unit 10 with a time delay of 0 from the reference.

[0135] In this manner, the laser irradiation device 200 can irradiate the substrate 1 with the laser light L and form a pattern on the substrate 1.

[0136] That is, in the laser irradiation device 200, when the detection signal of the substrate 1 by the detection unit 300 is detected at a timing earlier than the period of the irradiation reference pulse, a timer that counts the irradiation reference pulses at a predetermined period of the irradiation reference pulse is started. On the other hand, when the detection signal of the substrate 1 by the detection unit 300 is detected at a timing later than the irradiation reference pulse timing, the timer is started in synchronization with the irradiation reference timing converted from the detection signal of the substrate 1 by the detection unit 300. As a result, even if there is variation in the pitch of the substrates 1 conveyed to the irradiation area Ar, the irradiation start position of the irradiation unit 10 with the laser light L on the substrate 1 entering the irradiation area Ar can be accurately determined so that the variation in the pitch of the substrates 1 is corrected. Furthermore, even if there is variation in the conveyance pitch of the substrates and the substrate spacing becomes narrow, it is possible to avoid the problem of being unable to print on one of the substrates, and a highly productive laser irradiation device can be achieved that can stably laser print display patterns on each substrate.

[0137] <Changes in properties of base material 1> FIG. 17 shows an example of a change in the properties of the substrate 1. FIG. 17(a) shows a recessed portion formed by evaporating the surface of the substrate 1, and FIG. 17(b) shows a recessed portion formed by melting the surface of the substrate 1. In the case of FIG. 17(b), the peripheral edge of the recessed portion is raised compared to FIG. 17(a). FIG. 17(c) shows a change in the crystallization state of the surface of the substrate 1, and FIG. 17(d) shows a change in the foaming state inside the substrate 1. It is also possible to melt the substrate 1 and form a recessed portion by irradiating it with a CW laser having a wavelength of 355 nm or more and 1064 nm or less. Furthermore, if the laser light L is continued to be irradiated even after the substrate 1 has melted, the inside and surface of the substrate 1 can be foamed and become cloudy.

[0138] To change the crystallization state, for example, if the substrate is polyethylene terephthalate (PET), a CW laser with a wavelength of 355 nm or more and 1064 nm or less is irradiated to raise the temperature of the substrate 1 in one go, and then the PET of the substrate 1 can be brought into a crystallized state and made opaque by gradually cooling it by, for example, weakening the power. Note that if the PET is cooled rapidly by turning off the laser beam after raising the temperature, it will become amorphous and transparent.

[0139] The property changes of the substrate 1 are not limited to those shown in Fig. 17. The property changes of the substrate 1 may be caused by yellowing, oxidation reaction, surface modification, or the like of the substrate 1 made of a resin material.

[0140] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments of the present invention without departing from the scope of the claims.

[0141] All ordinal numbers, quantitative numbers, and other figures used in the description of the embodiments of the present invention are provided as examples to specifically explain the technology of the present invention, and the present invention is not limited to the illustrated figures. Furthermore, the connection relationships between components are provided as examples to specifically explain the technology of the present invention, and do not limit the connection relationships that realize the functions of the present invention.

[0142] For example, aspects of the present invention are as follows. <1> The laser irradiation device includes an irradiation unit that irradiates a substrate transported to an irradiation area with laser light, a detection unit that detects the timing of the substrate entering the irradiation area, and a control unit that controls the irradiation of the laser light by the irradiation unit, wherein a pattern is formed on the surface of the substrate by the laser light irradiated from the irradiation unit, and the control unit determines the start position of irradiation of the laser light by the irradiation unit onto the substrate entering the irradiation area in accordance with the entry timing detected by the detection unit. <2> When the entry timing output from the detection unit is different from the reference irradiation timing and the transport is performed at a timing different from the reference irradiation timing, the irradiation unit starts irradiation at a position different from the irradiation reference start position determined by the reference irradiation timing. <1> The laser irradiation device is described in <3> the control unit determines at least one of the irradiation start timing and the irradiation start position of the laser light based on a converted distance converted from a time difference between an irradiation reference timing and the entry timing output from the detection unit; <1> or the above <2> The laser irradiation device is described in <4> When the timing at which the detection signal is received by the detection unit is earlier than the irradiation reference timing, the irradiation start position downstream of the irradiation reference start position is determined based on a converted distance converted by the time difference between the respective timings. <1> From the above <3> The laser irradiation device is described in any one of the above. <5> When the detection signal from the detection unit is detected at a timing earlier than the timing of an irradiation reference pulse, a timer is started that counts the irradiation reference pulses at a predetermined cycle of the irradiation reference pulses, and when the detection signal is detected at a timing later than the irradiation reference timing, the timer is started in synchronization with the irradiation reference timing converted from the detection signal. <1> From the above <4> The laser irradiation device is described in any one of the above. <6> The irradiation reference pulse is set to a time shorter than the pitch timing period of the substrate. <1> From the above <5> The laser irradiation device is described in any one of the above. <7> The illumination reference pulse is set according to the following formula: Irradiation time < timer period of the irradiation reference pulse < substrate conveyance pitch period - error value The aforementioned <1> From the above <6> The laser irradiation device is described in any one of the above. <8> A laser irradiation method using a laser irradiation device, wherein the laser irradiation device uses an irradiation unit to irradiate a substrate transported to an irradiation area with laser light, a detection unit to detect the timing of the substrate entering the irradiation area, a control unit to control the irradiation of the laser light by the irradiation unit, a pattern is formed on the surface of the substrate by the laser light irradiated from the irradiation unit, and the control unit determines a start position for irradiation of the laser light by the irradiation unit onto the substrate entering the irradiation area in accordance with the entry timing detected by the detection unit. [Explanation of symbols]

[0143] 1 Base material 6 Control Unit 61 Irradiation data input section 62 Profile data specification section 63 Storage area 64 Control data generation unit 65 Laser irradiation control unit 651 Light Intensity Control Unit 652 Pulse control section 66 Laser scanning control unit 67 59ms timer section 68 Irradiation start position correction amount calculation unit 69 Delay Section 10 Irradiation unit 21 Pulse laser oscillator 22 Beam Expander 221 Galvanometer Mirror 222 Galvanometer Mirror 23 Scanning unit 241 fθ lens 25 Synchronous detection unit 200 Laser irradiation device 300 Detection unit 301 Light emitting element for transport detection 302 Light receiving element for transport detection 400 surface 500 pitch dividing device 501 CPU 502 ROM 503 RAM 504 HD 505 HDD controller 506 Display 508 External device connection I / F 509 Network I / F 510 Bus Line 511 keyboard 512 pointing device 513 DVD-RW 514 DVD-RW drive 515 Recording Media 516 Media I / F Ar irradiation area L laser light LSL distance A, B, C arrows [Prior art documents] [Patent documents]

[0144] [Patent Document 1] Patent Publication No. 2021-037685

Claims

1. an irradiation unit that irradiates a substrate transported to an irradiation region with laser light; a detection unit that detects the timing at which the base material enters the irradiation area; a control unit that controls the irradiation of the laser light by the irradiation unit, forming a pattern on the surface of the base material by the laser light irradiated from the irradiation unit; The control unit determines a start position for irradiating the base material with the laser light by the irradiation unit according to the entry timing detected by the detection unit.

2. 2. The laser irradiation device according to claim 1, wherein the irradiation unit starts irradiation at a position different from an irradiation reference start position determined by the reference irradiation timing when the entry timing output from the detection unit is different from the reference irradiation timing during transport.

3. 3. The laser irradiation device according to claim 1, wherein the control unit determines at least one of the irradiation start timing and the irradiation start position of the laser light based on a converted distance converted from a time difference between an irradiation reference timing and the entry timing output from the detection unit.

4. 3. The laser irradiation device according to claim 1, wherein when the timing at which the detection signal is received by the detection unit is earlier than the irradiation reference timing, the irradiation start position is determined downstream of the irradiation reference start position based on a converted distance converted by the time difference between the respective timings.

5. When the detection signal from the detection unit is detected at a timing earlier than the timing of the irradiation reference pulse, a timer is started to count the irradiation reference pulse at a predetermined cycle of the irradiation reference pulse; 3. The laser irradiation device according to claim 1, wherein when the detection signal is detected at a timing later than an irradiation reference timing, the timer is started in synchronization with the irradiation reference timing converted from the detection signal.

6. 3. The laser irradiation device according to claim 1, wherein the irradiation reference pulse is set to have a time shorter than a pitch timing period of the substrate.

7. The illumination reference pulse is set according to the following formula: Irradiation time < timer period of the irradiation reference pulse < substrate conveyance pitch period - error value 3. The laser irradiation device according to claim 1 or 2.

8. A laser irradiation method using a laser irradiation device, the laser irradiation device comprising: The irradiation unit irradiates the substrate conveyed to the irradiation area with laser light, A detection unit detects the timing when the base material enters the irradiation area, a control unit controls the irradiation of the laser light by the irradiation unit; forming a pattern on the surface of the base material by the laser light irradiated from the irradiation unit; the control unit determines a start position for irradiating the base material with the laser light by the irradiation unit according to the entry timing detected by the detection unit.

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