Drawing device and drawing method

Abstract

Improve drawing quality. [Solution] In the drawing device, a modulator controls the irradiation of light onto each spot in a linearly arranged spot train on a drawing target, a rotator rotates the spot train, and a movement mechanism moves the spot train in a direction perpendicular to the spot arrangement direction. When a drawing position on the drawing target overlaps only with either a destination pass region 961 through which the spot train will pass as the spot train moves forward or a destination pass region 962 through which the spot train will pass as the spot train moves backward, a predetermined amount of light is irradiated onto the drawing position during the forward movement or the later movement, and when the drawing position overlaps both the destination pass region 961 and the later pass region 962, light is irradiated onto the drawing position during at least one of the forward movement and the later movement, and the total amount of light is equal to the drawing light amount.

Description

[Technical Field]

[0001] The present invention relates to a technique for drawing on a drawing target by irradiating it with light. [Background technology]

[0002] Techniques for drawing images by irradiating light have been used in various fields. For example, Patent Document 1 discloses a technique for performing laser irradiation in a descriptive manner in any direction by rotating a line beam using a line beam rotation unit while moving an object to be irradiated in the X and Y directions. Furthermore, Patent Document 2 discloses a laser marking system that modulates the intensity distribution of a beam expanded in one direction and performs printing processing using the modulated beam. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-4877 [Patent Document 2] Japanese Patent Application Publication No. 2023-231 Summary of the Invention [Problem to be solved by the invention]

[0004] As in Patent Document 1, by controlling the direction of the line beam and moving it in any direction, the drawing time is shortened and efficient drawing is achieved. However, while drawing can be performed in any direction, the amount of light per unit area applied to the drawing target is prone to variation. The variation in the amount of light per unit area reduces the quality of drawing.

[0005] The present invention has been made in view of the above-mentioned problems, and has as its object to improve the quality of drawing in a drawing device that can draw in any direction. [Means for solving the problem]

[0006] A first aspect of the present invention is a drawing device that draws images by irradiating light, comprising a laser light source, a modulator that spatially modulates the light beam from the laser light source, a rotator that rotates the light beam guided from the modulator, a movement mechanism that moves the irradiation position of the light beam guided from the rotator on an object to be drawn, and a control unit that controls the modulator, the rotator, and the movement mechanism, wherein the irradiation of light to each spot in a linearly arranged spot train on the object to be drawn is controlled by the modulator, the spot train is rotated by the rotator, and the spot train is moved by the movement mechanism in a direction perpendicular to the spot arrangement direction, and the forward direction is controlled by the modulator. When a drawing position on the drawing object overlaps with only either a destination area through which the spot train passes as the spot train moves forward or a destination area through which the spot train passes as the spot train moves backward, the control unit controls the one drawing position to be irradiated with a predetermined amount of light for drawing during the destination area or the destination area, and when a drawing position on the drawing object overlaps with the destination area and the destination area, the control unit controls the one drawing position to be irradiated with light during at least one of the destination area or the destination area, and the total amount of light is equal to the drawing light amount.

[0007] A second aspect of the present invention is a drawing device of the first aspect, wherein when the one drawing position overlaps with the previous passing area and the subsequent passing area, the control unit controls the one drawing position to be irradiated with the drawing light amount only during either the previous movement or the subsequent movement.

[0008] A third aspect of the present invention is a drawing device according to the second aspect, wherein, under the control of the control unit, in a region of a drawing area, which is a collection of drawing positions on the drawing target, that overlaps with the previous passing area and the subsequent passing area, the proportion of drawing positions to which light is irradiated only during the previous movement gradually decreases from an edge that exists only inside the previous passing area to an edge that exists only inside the subsequent passing area.

[0009] A fourth aspect of the present invention is a drawing device that draws by irradiating light, comprising a laser light source, a modulator that spatially modulates the light beam from the laser light source, a rotator that rotates the light beam guided from the modulator, a movement mechanism that moves the irradiation position of the light beam guided from the rotator on the drawing object, and a control unit that controls the modulator, the rotator, and the movement mechanism, wherein the irradiation of light to each spot in a linearly arranged spot train on the drawing object is controlled by the modulator, the spot train is rotated by the rotator, and the spot train is moved by the movement mechanism in a direction perpendicular to the spot arrangement direction, and under the control of the control unit, when the movement of the spot train by the movement mechanism is curved, the amount of irradiated light or the proportion of ON state time is increased for spots in the spot train that are located further out from the movement path.

[0010] A fifth aspect of the present invention is the drawing device of the fourth aspect, wherein the ratio of the amount of irradiation light to the moving distance of each spot is constant under the control of the control unit.

[0011] A sixth aspect of the present invention is a drawing method for drawing by irradiating light, comprising: a) a step of guiding light from a laser light source to a series of spots arranged in a line on a drawing object while moving the series of spots in a direction perpendicular to the arrangement direction of the spots; and b) a step of controlling the irradiation of light to each spot while step a) is being performed, wherein the arrangement direction of the series of spots is changeable, and when a drawing position on the drawing object overlaps with only either a forward passing area through which the series of spots will pass as the series of spots move forward or a backward passing area through which the series of spots will pass as the series of spots move backward, a predetermined amount of light for drawing light is irradiated to the one drawing position during the forward movement or the backward movement, and when a drawing position on the drawing object overlaps with both the forward passing area and the backward passing area, light is irradiated to the one drawing position during at least one of the forward movement and the backward movement under the control of the control unit, and the total amount of light is equal to the drawing light amount.

[0012] A seventh aspect of the present invention is a drawing method for drawing by irradiating light, comprising the steps of: a) guiding light from a laser light source to a series of spots arranged in a straight line on a drawing object while moving the series of spots in a direction perpendicular to the arrangement direction of the spots; and b) controlling the irradiation of light to each spot while step a) is being performed, wherein when the movement of the series of spots is curved, the more outer the spots in the series of spots are located on the movement path, the greater the amount of irradiated light or the proportion of time that they are in an ON state. [Effects of the Invention]

[0013] According to the present invention, the quality of drawing can be improved. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a drawing device. [Figure 2] FIG. 2 is a diagram showing components of an optical head. [Figure 3] FIG. 2 is a diagram showing a control unit and its peripheral configuration. [Figure 4] FIG. 1 illustrates a modulator. [Figure 5] FIG. 1 is a diagram showing a spot train. [Figure 6] FIG. 10 is a diagram showing how drawing is performed by a spot train. [Figure 7] FIG. 2 is a diagram showing a flow of basic operations of the drawing device. [Figure 8] FIG. 10 is a diagram illustrating an example of movement of a spot train. [Figure 9A] FIG. 10 is a diagram showing how drawing is performed in the first pass area. [Figure 9B] FIG. 10 is a diagram showing how drawing is performed in the second passing area. [Figure 9C] FIG. 10 is a diagram showing how drawing is performed in the third passing area. [Figure 10] FIG. 10 is a diagram illustrating an example of further improving the quality of drawing. [Figure 11] FIG. 10 is a diagram illustrating an example of further improving the quality of drawing. [Figure 12]FIG. 10 is a diagram illustrating an example of movement of a spot train. [Figure 13] FIG. 10 is a diagram showing the relationship between spot position and illuminance. [Figure 14] 10 is a diagram illustrating an example of the relationship between the position of a spot and the irradiation timing of pulsed light. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] FIG. 1 is a diagram showing a schematic configuration of a drawing device 1 according to an embodiment of the present invention. FIG. 2 is a diagram showing components of an optical head 11 of the drawing device 1 arranged in a line. The drawing device 1 is a device that performs drawing by irradiating a drawing target with light. The drawing device 1 includes a laser light source 21, an illumination optical system 22, a modulator 23, an imaging optical system 24, a rotator 25, and a movement mechanism 26. The laser light source 21 emits a light beam 81, which is laser light. In FIGS. 1 and 2, the light beam 81 is represented by adding the reference symbol 81 to the optical axis. The laser light source 21 may be provided outside the optical head 11. In this case, the light emitted from the laser light source 21 is guided into the optical head 11.

[0016] The light beam 81 enters the illumination optical system 22, which shapes the cross-sectional shape of the light beam 81, i.e., the cross-sectional shape of the light beam of the light beam 81 in a plane perpendicular to the optical axis, into a desired shape. Specifically, the illumination optical system 22 shapes the cross-section of the light beam of the light beam 81 into a substantially rectangular shaped beam that is long in one direction (hereinafter referred to as the "long axis direction") and guides it to the modulator 23. In this way, the cross-sectional shape of the shaped light beam 81 is a substantially rectangular shape that is long in the long axis direction and short in the short axis direction perpendicular to the optical axis and the long axis direction. The long axis and short axis directions are directions perpendicular to the optical axis, i.e., the traveling direction of the light beam 81. The cross-sectional shape of the shaped light beam 81 can also be considered as a straight line extending in the long axis direction.

[0017] The illumination optical system 22 guides the light beam 81 to the modulator 23. The modulator 23 spatially modulates the light beam 81 from the laser light source 21. The configuration of the modulator 23 will be described later. The imaging optical system 24 forms an intermediate image 82 (see FIG. 2) of the modulator 23 at a predetermined position in front of the rotator 25.

[0018] Rotator 25 is a so-called image rotation optical system that can rotate the light beam by any angle around the optical axis. This allows the spot train on the target to be rotated around an axis perpendicular to the surface of the target, as will be described later. As rotator 25, for example, an optical unit consisting of a Dove prism (a trapezoidal image-rotating prism with a certain thickness) and a motor that rotates the Dove prism, or an image-rotating mirror unit that achieves the same function using multiple mirrors and motors that rotate each mirror, can be used.

[0019] The moving mechanism 26 is a so-called scanning optical system, and as shown in FIG. 2, has a lens 261, a pair of galvanometer mirrors 262 (shown as rectangles), and an fθ lens 263. The pair of galvanometer mirrors moves the irradiation position of the light beam 81 in the X and Y directions in FIG. 1. In FIG. 1, the target to be imaged is the top surface 91 of a semiconductor package 9. The top surface 91 is parallel to the XY plane shown in FIG. 1 and perpendicular to the Z direction. Hereinafter, the top surface 91 will be referred to as the "target to be imaged 91." The target to be imaged 91 is a metal surface. The moving mechanism 26 moves the irradiation position of the light beam 81, which is guided from the rotator 25, on the target to be imaged 91. In FIG. 1, a plurality of semiconductor packages 9 are arranged on a tray 92, and the moving mechanism 26 sequentially performs image drawing on the plurality of semiconductor packages 9.

[0020] The drawing device 1 further includes a control unit. FIG. 3 is a diagram showing the control unit 3 and its peripheral configuration. The control unit 3 is, for example, a normal computer including a processor, a memory, an input / output unit, and a bus. The configuration of the control unit 3 may be modified in various ways. The control unit 3 controls at least the modulator 23, the rotator 25, and the movement mechanism 26. This controls the direction and movement of the modulated light beam 81 on the drawing target 91.

[0021] 4 is a diagram showing the modulator 23. The modulator 23 converts the light beam 81 from the illumination optical system 22 into a one-dimensional spatially modulated light beam 81. As the modulator 23, for example, a PLV (Planar Light Valve) that can perform modulation at high speed and can withstand kW-class laser light is used. Although the PLV is a two-dimensional spatial light modulator, the optical head 11 uses it as a one-dimensional spatial modulator.

[0022] Fig. 4 is a simplified diagram showing the structure of modulator 23, which is a PLV. Modulator 23 includes a plurality of substantially rectangular pixels 231 arranged in a matrix (i.e., two-dimensionally arranged) on a substrate (not shown). In modulator 23, the surfaces of the plurality of pixels 231 form modulation surface 234. In the example shown in Fig. 4, M pixels 231 are arranged in the vertical direction and N pixels 231 are arranged in the horizontal direction in the figure. The horizontal direction in Fig. 4 corresponds to the major axis direction of shaped light beam 81, and the vertical direction in Fig. 4 corresponds to the minor axis direction.

[0023] Each pixel 231 is a modulation mechanism including a fixed member 232 and a movable member 233. The fixed member 232 is a planar, approximately rectangular member fixed to the substrate, and has a substantially circular opening in the center. The movable member 233 is a substantially circular member provided in the opening of the fixed member 232. A fixed reflecting surface is provided on the upper surface of the fixed member 232 (i.e., the surface on the near side in the direction perpendicular to the paper surface in FIG. 4). A movable reflecting surface is provided on the upper surface of the movable member 233. The movable member 233 is movable in the direction perpendicular to the paper surface in FIG. 4.

[0024] In each pixel 231, the relative position of the fixed member 232 and the movable member 233 in the direction perpendicular to the paper surface in FIG. 4 is changed, so that the reflected light from the pixel 231 is switched between zeroth-order (diffracted) light (i.e., specularly reflected light) and non-zeroth-order diffracted light. In other words, in the pixel 231, the movable member 233 moves relative to the fixed member 232, so that light modulation using a diffraction grating is performed. The zeroth-order light emitted from the modulator 23 is guided to the drawing target 91 by the movement mechanism 26. In addition, the non-zeroth-order diffracted light (mainly first-order diffracted light) emitted from the modulator 23 is appropriately blocked so as not to reach the drawing target 91.

[0025] In the modulator 23, the diffraction state of reflected light from M pixels 231 (hereinafter also referred to as a "pixel column 230") arranged in a vertical row in FIG. 4 is the same. That is, when the reflected light from one pixel 231 is zero-order light, the reflected light from all other pixels 231 (i.e., M-1 pixels 231) in the pixel column 230 including that pixel 231 is also zero-order light. Also, when the reflected light from one pixel 231 is non-zero-order diffracted light, the reflected light from all other pixels 231 in the pixel column 230 including that pixel 231 is also non-zero-order diffracted light. That is, the modulator 23 does not perform modulation in the minor axis direction of the light beam 81, but performs modulation in the major axis direction. In this way, in the modulator 23, the M pixels 231 in one pixel column 230 (i.e., M modulation mechanisms) function as one modulation element corresponding to one unit space. The modulator 23 functions as a one-dimensional spatial light modulator having N modulation elements aligned in a row in the long axis direction of the light beam 81. In a preferred example, N is 1000 or more.

[0026] FIG. 5 is a diagram showing how a light beam 81 is irradiated onto a drawing target 91, showing a spot array 80 in which multiple spots 83 are linearly arranged on the drawing target 91. For convenience, each spot 83 is represented by a square in FIG. 5. Light from M pixels 231 in one pixel array 230 in FIG. 4 is directed to converge onto one spot 83 in FIG. 5. As a result, the modulator 23 controls (ON / OFF control or light intensity control) the irradiation of light onto each spot 83 in the spot array 80 in FIG. 5. The rotator 25 can rotate the spot array 80 on the drawing target 91 around an axis perpendicular to the surface of the drawing target 91, as indicated by an arrow 841. That is, the arrangement direction of the spot array 80 can be changed. The movement mechanism 26 moves the spot array 80 in a direction parallel to the surface of the drawing target 91 and perpendicular to the arrangement direction of the spots 83 (the direction indicated by an arrow 842). The "perpendicular direction" here is not limited to a direction perpendicular to the arrangement direction of the spots 83 in the strict sense, but may be any direction that is approximately perpendicular.

[0027] FIG. 6 is a diagram illustrating how drawing is performed by the spot array 80. Blank spots 83 indicate spots to which light is not guided, and hatched spots 83 indicate spots to which light is guided. As the spot array 80 moves to the right as indicated by arrow 843, drawing is performed in a region through which the spot array 80 passes (the region indicated by reference numeral 94, hereinafter referred to as the "passing region"), and in the region through which the spot array 80 passes (the region indicated by reference numeral 95, hereinafter referred to as the "drawing region"). Here, "drawing" refers to a change in the surface of the drawing target 91 by irradiation with light, i.e., processing. For example, it refers to causing a chemical or physical change in the surface material by heating or light irradiation, or removing a portion of the surface material by heating or light irradiation (which may also be included in the physical change). The "drawing region" is a set of positions to be drawn on the drawing target 91 (hereinafter referred to as "drawing positions"), and one drawing position is a unit of drawing by the spot 83.

[0028] 7 is a diagram showing the flow of the basic operation of the imaging device 1. First, the imaging device 1 moves the spot array 80 to a start position for performing the first imaging (step S11). However, in reality, at this stage, no light is guided to each spot 83, and therefore the pair of galvanometer mirrors of the moving mechanism 26 simply assume the corresponding posture.

[0029] Next, the movement of the spot array 80 is started by the movement mechanism 26 (step S12), and almost simultaneously, the modulator 23 modulates the light beam 81 (step S13). As a result, drawing is performed in a required area on the drawing target 91, as exemplified in FIG. 6. Note that steps S12 and S13 may be performed simultaneously, or step S13 may be performed immediately before step S12. In this case, control of the modulator 23 is started by step S13, but control is performed to maintain a state in which light is not guided to each spot 83 (i.e., an OFF state) until the movement of step S12 is started.

[0030] When the predetermined drawing is performed, the modulator 23 stops modulating the light beam 81 (step S14), and almost simultaneously, the movement of the spot train 80 is stopped by the movement mechanism 26 (step S15). This completes the drawing in one movement of the spot train 80, i.e., the drawing in the first passing area of ​​the spot train 80. Steps S14 and S15 may be performed simultaneously, or step S15 may be performed immediately before step S14. In this case, before the movement of the spot train 80 is stopped in step S15, control is performed to maintain a state in which light is not guided to each spot 83 (i.e., an OFF state), and after the movement of the spot train 80 has stopped, the control of maintaining the OFF state ends.

[0031] As described above, steps S12 and S15 execute the process of guiding light from the laser light source 21 to the spot array 80 arranged in a line on the drawing target 91, while moving the spot array 80 in a direction perpendicular to the arrangement direction of the spots 83. Steps S13 and S14 execute the process of controlling the irradiation of light onto each spot 83 while the spot array 80 is being moved.

[0032] When the next drawing is to be performed (step S16), the moving mechanism 26 moves the spot train 80 to a start position for the next drawing (step S11). Then, steps S12 to S15 are executed, thereby performing desired drawing in the next passing region of the spot train 80. When drawing has been performed in the passing region the required number of times, drawing by the drawing device 1 ends (step S16).

[0033] 8 is a diagram illustrating the movement of spot train 80 when drawing the letter "Z." The rectangle labeled 961 indicates the (first) passing area of ​​spot train 80 during the first movement of spot train 80, with spot train 80 moving in the direction indicated by arrow 851. The rectangle labeled 962 indicates the (second) passing area of ​​spot train 80 during the second movement of spot train 80, with spot train 80 moving in the direction indicated by arrow 852. The rectangle labeled 963 indicates the (third) passing area of ​​spot train 80 during the third movement of spot train 80, with spot train 80 moving in the direction indicated by arrow 853.

[0034] FIG. 9A is a diagram showing how drawing is performed in a first passage region 961. While the spot train 80 moves in the direction indicated by arrow 851, the ON / OFF of light irradiation to each spot 83 is controlled, and drawing is performed in a region 971 indicated by parallel hatching. FIG. 9B is a diagram showing how drawing is performed in a second passage region 962. While the spot train 80 moves in the direction indicated by arrow 852, the ON / OFF of light irradiation to each spot 83 is controlled, and drawing is performed in a region 972 indicated by parallel hatching. FIG. 9C is a diagram showing how drawing is performed in a third passage region 963. While the spot train 80 moves in the direction indicated by arrow 853, the ON / OFF of light irradiation to each spot 83 is controlled, and drawing is performed in a region 973 indicated by parallel hatching.

[0035] 8, among the areas to be drawn as the letter "Z," the area indicated by the hatched reference numeral 981 overlaps with the first pass area 961 and the second pass area 962. Therefore, if drawing is performed in area 981 during the first movement of spot train 80 and again during the second movement of spot train 80, drawing will be performed twice in area 981. In this case, excessive processing will be performed on area 981, and, for example, the outline of area 981 will become conspicuous, degrading the drawing quality. The same applies to area 982, which overlaps with the second pass area 962 and the third pass area 963.

[0036] 9B, in the drawing device 1, when drawing is performed in the second movement, the modulator 23 is controlled so as not to draw in the region 981. That is, instruction data for the control unit 3 to control the modulator 23 so as not to draw in the region 981 is prepared in advance. Similarly, as shown in FIG. 9C, in the drawing device 1, when drawing is performed in the third movement, the modulator 23 is controlled so as not to draw in the region 982. That is, instruction data for the control unit 3 to control the modulator 23 so as not to draw in the region 982 is prepared in advance.

[0037] As described above, in the imaging device 1, multiple passing areas that extend in various directions and overlap in various ways are set, but even with this imaging method, overlapping imaging is not performed. This makes it possible to keep the fluence, which is the energy supplied per unit area, constant throughout the entire imaging area. As a result, the imaging quality is improved.

[0038] In the operations shown in FIGS. 9A to 9C , the overlapping region may not be irradiated with light during the earlier movement of the spot train 80, but may be irradiated with light during the later movement. When the above operation of avoiding overlapping irradiation in the overlapping region is considered with respect to each drawing position to be drawn, each drawing position in the non-overlapping region overlaps with only either the forward pass region through which the spot train 80 passes as the spot train 80 moves forward, or the backward pass region through which the spot train 80 passes as the spot train 80 moves backward. Then, under the control of the control unit 3, the drawing position is irradiated with a predetermined amount of light (hereinafter referred to as the “drawing light amount”) required for drawing during the earlier or later movement. Each drawing position in the overlapping region overlaps with both the forward pass region and the backward pass region, and under the control of the control unit 3, the drawing position is irradiated with the above amount of light during only either the earlier or later movement. Note that when the drawing region is considered to be a collection of drawing positions, the “drawing position” and “position” in the above description can be interpreted as “drawing region” and “region.”

[0039] 10 is a diagram showing an example in which the quality of drawing is further improved while the fluence in the region 981 in FIG. 8 is kept constant. The side of the region 981 indicated by reference numeral 983 is part of the contour of the passing region 962 and exists inside the passing region 961. In other words, the side 983 is a side that exists only inside the passing region 961. On the other hand, the side of the region 981 indicated by reference numeral 984 is part of the contour of the passing region 961 and exists inside the passing region 962. In other words, the side 984 is a side that exists only inside the passing region 962.

[0040] In region 981, the proportion of the number of drawing positions illuminated with light only during the first movement gradually decreases from side 983 toward side 984. In the example of FIG. 10 , multiple triangles 985 with their bases on side 983 and vertices on side 984 are included in the drawing region during the first movement, and multiple triangles 986 with their bases on side 984 and vertices on side 983 are included in the drawing region during the second movement. As a result, in region 981, the boundary between the drawing region during the first movement and the drawing region during the second movement appears "jagged." By gradually decreasing the proportion of the number of drawing positions illuminated with light only during the first movement from side 983 toward side 984, the boundary between the drawing region during the first movement and the drawing region during the second movement becomes less noticeable, further improving the drawing quality.

[0041] Note that "the proportion of the number of drawing positions gradually decreases" includes cases where the proportion does not decrease (remains constant) in some areas. For example, as shown in FIG. 11 , in region 981, a meandering curve away from both sides 983 and 984 may be the boundary between region 987 included in the drawing region during the first movement and region 988 included in the drawing region during the second movement. In this case, in the vicinity of sides 983 and 984, the proportion of the number of drawing positions irradiated with light only during the first movement of spot array 80 does not change. It is preferable that the boundary between the region included in the drawing region during the first movement and the region included in the drawing region during the second movement has two or more convex portions toward side 983 and also has two or more convex portions toward side 984.

[0042] In the region 981, the amount of light to the spot 83 may be set to an intermediate value rather than being ON / OFF controlled. For example, during the first movement of the spot train 80, light may be irradiated at 50% of the amount of light required for drawing at each drawing position in the region 981, and during the second movement of the spot train 80, light may again be irradiated at 50% of the amount of light required for drawing at each drawing position in the region 981. During the first movement, light may be irradiated at a higher light intensity toward the side 983 in the region 981, and during the second movement of the spot train 80, light may be irradiated at a higher light intensity toward the side 984 in the region 981, with the total amount of light irradiated for the two movements being the drawing light amount. In this way, light may be irradiated at various rates toward the region 981 during the first movement of the spot train 80 and the second movement of the spot train 80.

[0043] In other words, when the drawing position on the drawing target 91 overlaps with the previous pass area and the subsequent pass area, light is irradiated onto the drawing position during at least one of the previous movement and the subsequent movement under the control of the control unit 3, and the total light amount of light is made equal to the drawing light amount. Here, "equal to the drawing light amount" does not necessarily have to be equal to the drawing light amount in the strict sense, but means that the total light amount is substantially equal to the drawing light amount within the range that achieves drawing of a certain quality.

[0044] In addition, as shown in Figures 9A to 9C, when the drawing position overlaps with a previous passing area and a subsequent passing area, the process of generating drawing data can be facilitated by adopting a method in which the control unit 3 controls the drawing position to be irradiated with the drawing light amount only during either the previous movement or the subsequent movement (i.e., by not adopting an intermediate light amount such as 50% of the drawing light amount).

[0045] FIG. 12 is a diagram illustrating the movement of spot train 80 when drawing the letter "C" (assuming it is an arc). The dashed band-like area indicated by reference numeral 965 indicates the area through which spot train 80 passes, and spot train 80 moves in the direction indicated by arrow 855. As spot train 80 moves in an arc shape as indicated by arrow 855, the irradiation of light onto each spot 83 is controlled, and drawing is performed in hatched area 975. The flow of operations during drawing is the same as in FIG. 7 (however, there is no repeated processing).

[0046] FIG. 13 is a diagram showing the relationship between the position of a spot 83 in a spot train 80 and the illuminance of the spot 83 (or the amount of light guided to the spot 83) when drawing the letter "C." When drawing the letter "C," the spots 83 in the spot train 80 that overlap the letter "C" are set to a state in which light is guided, and the others are set to an OFF state. At this time, as shown in FIG. 13, the illuminance of the spots 83 is higher as they are positioned further out on the arc. In other words, the amount of light guided to the spots 83 is greater as they are further out. When the modulator 23 is a PLV, the adjustment of the light amount is realized by adjusting the difference in height between the fixed member 232 and the movable member 233 in FIG. 4, thereby adjusting the amount of light of the zero-order light.

[0047] When drawing is a thermal process such as melting the material to be drawn or forming an oxide film, the temperature reached on the processing surface is proportional to the illuminance and inversely proportional to the scanning speed. Therefore, in the drawing device 1, the light intensity is increased toward the outer spots 83, so that the fluence (energy supplied per unit area) of the outer region of the letter "C" is made equal to the fluence of the inner region. As a result, the quality of drawing can be improved compared to when such light intensity adjustment is not performed.

[0048] Figure 13 shows the control of the modulator 23 by the control unit 3 when the intensity of the irradiated light affects the degree of processing during drawing. Depending on the drawing target 91, drawing may be performed by using a pulsed laser to instantaneously melt or ablate the material. In this case, to achieve uniform drawing, it is necessary to maintain a constant irradiation density of pulses of a certain intensity. The fluence corresponds to the number of pulses per unit area, i.e., the temporal duty of the light irradiation, and by maintaining a constant fluence in the drawing area, the quality of the drawing is improved.

[0049] FIG. 14 is a diagram illustrating the relationship between the positions of spots 83 in a spot train 80 and the timing of pulsed light irradiation when a pulsed laser is used. In FIG. 14, the positions of spots 83 that do not overlap with the letter "C" are omitted. In FIG. 14, gray squares correspond to irradiation of pulsed light, and white squares correspond to non-irradiation of pulsed light. As shown in FIG. 14, the spots 83 located closer to the center of the letter "C" have a greater number of times when they are not irradiated with pulsed light.

[0050] As described above, when the movement of spot array 80 by moving mechanism 26 is curved, the control unit 3 controls spots 83 located further out in the movement path in spot array 80 to have a larger irradiated light intensity or a larger proportion of ON-state time, thereby improving the quality of the drawing when drawing a curve. In particular, the control unit 3 controls the ratio of the irradiated light intensity to the movement distance of each spot 83 to be constant, thereby making it possible to draw a curve more appropriately. "The ratio of the irradiated light intensity to the movement distance of the spot is constant" means that the ratio of the average irradiated light intensity is constant when viewed over a range large enough for the resolution of drawing by modulation.

[0051] The rendering device 1 may be modified in various ways.

[0052] For example, the modulator 23 that spatially modulates the light beam from the laser light source 21 is not limited to a PLV, and various other modulators can be used. For example, a GLV (registered trademark) (Grating Light Valve) may be used as the modulator 23. The modulator 23 may be any device that can one-dimensionally spatially modulate a line beam (a light beam with a linear cross section). The spatial modulation may be performed by only controlling ON / OFF for each modulation unit, or by controlling modulation to an arbitrary light intensity.

[0053] The rotator 25 rotates the spot array 80 on the drawing target 91 around an axis perpendicular to the surface of the drawing target 91, but the axis of the rotation center does not need to be perpendicular in the strict sense to the surface of the drawing target 91. Depending on the arrangement of optical elements, the axis of the rotation center may be slightly inclined with respect to the normal to the surface, as long as it is substantially perpendicular to the surface of the drawing target 91.

[0054] The movement mechanism 26 may have various configurations as long as it can move the irradiation position of the light beam 81 guided from the rotator 25 on the drawing target 91. For example, a mechanism that moves the drawing target 91 two-dimensionally in the horizontal direction relative to the optical head 11 may be used as the movement mechanism. Alternatively, the light beam 81 may be movable in one direction, and the drawing target 91 may be movable in a horizontal direction perpendicular to the above direction. In this way, the movement mechanism moves the irradiation position of the light beam 81 relatively on the drawing target 91.

[0055] The shape drawn by the drawing device 1 is not limited to a character, but may be a line drawing or a pattern. The shape to be drawn is preferably a shape that can be drawn efficiently along a line.

[0056] The imaging device 1 can be used in various fields where imaging is performed by irradiating light. For example, the configuration of the imaging device 1 can be used in a three-dimensional modeling device that performs three-dimensional modeling by performing imaging on each layer. The imaging target may be the surface of various materials, such as metal, resin, glass, or wood.

[0057] The configurations in the above-described embodiment and each modification may be combined as appropriate as long as they are not mutually contradictory. [Explanation of symbols]

[0058] 1 Drawing device 3. Control Unit 21 Laser light source 23 Modulator 25 Rotator 26 Moving mechanism 80 Spot Row 81 Light Beam 83 spots 91 Drawing Target 961~963,965 Passage area 983,984 sides Steps S11 to S16

Claims

1. A drawing device that draws by irradiating light, a laser light source; a modulator that spatially modulates the light beam from the laser light source; a rotator for rotating the light beam directed from the modulator; a moving mechanism for moving an irradiation position of the light beam guided from the rotator on a drawing target; a control unit that controls the modulator, the rotator, and the movement mechanism; Equipped with the modulator controls the irradiation of light onto each spot of a spot train linearly arranged on the target to be drawn, the rotator rotates the spot train, and the movement mechanism moves the spot train in a direction perpendicular to the spot arrangement direction; when one drawing position on the drawing target overlaps only with either a destination area through which the spot train passes as the spot train moves forward or a destination area through which the spot train passes as the spot train moves backward, a predetermined amount of light is irradiated onto the one drawing position during the forward movement or the backward movement under the control of the control unit; A drawing device in which, when a drawing position on the drawing object overlaps with the previous passing area and the subsequent passing area, light is irradiated onto the drawing position during at least one of the previous movement and the subsequent movement under the control of the control unit, and the total light amount of the light is equal to the drawing light amount.

2. 2. The drawing device according to claim 1, A drawing device in which, when the one drawing position overlaps with the previous passing area and the subsequent passing area, the control unit controls the one drawing position to be irradiated with the drawing light amount only during either the previous movement or the subsequent movement.

3. 3. The drawing device according to claim 2, A drawing device in which, under the control of the control unit, in an area of ​​a drawing area, which is a collection of drawing positions on the drawing object, that overlaps with the previous passing area and the subsequent passing area, the proportion of drawing positions to which light is irradiated only during the previous movement gradually decreases from an edge that exists only inside the previous passing area to an edge that exists only inside the subsequent passing area.

4. A drawing device that draws by irradiating light, a laser light source; a modulator that spatially modulates the light beam from the laser light source; a rotator for rotating the light beam directed from the modulator; a moving mechanism for moving an irradiation position of the light beam guided from the rotator on a drawing target; a control unit that controls the modulator, the rotator, and the movement mechanism; Equipped with the modulator controls the irradiation of light onto each spot of a spot train linearly arranged on the target to be drawn, the rotator rotates the spot train, and the movement mechanism moves the spot train in a direction perpendicular to the spot arrangement direction; A drawing device in which, under the control of the control unit, when the movement of the spot row by the moving mechanism is curved, the amount of irradiated light or the proportion of time in the ON state is increased for spots in the spot row that are located further out from the movement path.

5. 5. The drawing device according to claim 4, A drawing device in which the ratio of the amount of irradiation light to the moving distance of each spot is constant under the control of the control unit.

6. A drawing method for drawing by irradiating light, comprising: a) directing light from a laser light source onto a linearly arranged spot array on a target object, and moving the spot array in a direction perpendicular to the spot array direction; b) controlling the irradiation of light onto each spot while the a) step is being performed; Equipped with The arrangement direction of the spot array is changeable, when one drawing position on the drawing target overlaps only with either a destination area through which the spot train passes as the spot train moves forward or a destination area through which the spot train passes as the spot train moves backward, a predetermined amount of light is irradiated onto the one drawing position during the forward movement or the backward movement; A drawing method in which, when a drawing position on the drawing object overlaps with the previous passing area and the subsequent passing area, light is irradiated onto the drawing position during at least one of the previous movement and the subsequent movement under the control of the control unit, and the total light amount of the light is equal to the drawing light amount.

7. A drawing method for drawing by irradiating light, comprising: a) directing light from a laser light source onto a linearly arranged spot array on a target object, and moving the spot array in a direction perpendicular to the spot array direction; b) controlling the irradiation of light onto each spot while the a) step is being performed; Equipped with A drawing method in which, when the movement of the spot train is curved, the intensity of irradiated light or the proportion of time in an ON state of the spots located on the outer side of the movement path of the spot train is increased.

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