Laser line marking device

Abstract

The purpose of the present invention is to provide a laser reticle that can be reduced in size. The laser line device (10) is provided with a light projection part (18) and a rotating part (20). The rotating unit (20) has: a driven gear (36) that rotates integrally with the light projecting unit (18); a drive gear (56); a motor (42); a knob (32); a planetary gear mechanism (58); a first drive wheel (54) that rotates integrally with the sun gear (64); a second drive wheel (60) of external teeth provided over 360 degrees on the outer peripheral surface of the ring gear (66); a motor worm (42c) provided on a motor shaft (42b) of the motor (42); and a knob worm (32b) provided on a knob shaft (32a) of the knob (32). The first drive wheel (54) is engaged with the motor worm (42c), and the second drive wheel (60) is engaged with the knob worm (32b).

Description

laser marking device Technical Field

[0001] The present invention relates to a laser marking device having a projection section that projects a laser-formed mark onto an object and a rotating section that rotates the projection section horizontally. Background Technology

[0002] Laser marking devices are known for projecting lines onto objects such as walls, ceilings, and floors at construction sites. The markings mainly include a horizontal and vertical reference projected onto the wall, a ground reference projected onto the floor, and a ceiling reference projected onto the ceiling. Some laser marking devices automatically rotate the projection unit using a motor to align the vertical reference with the target position or to orient the horizontal reference in the desired direction without projecting it 360 degrees. Additionally, there are laser marking devices that allow for fine-tuning of the projection unit rotation via a hand-operated knob (Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-215019 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the laser line marker described in Patent Document 1, the motor-based drive mechanism and the knob-operated drive mechanism are set separately, making it larger and heavier compared to types without such mechanisms.

[0008] In addition, the laser marker described in Patent Document 1 has a DC motor suitable for high-speed rotation during automatic rotation and a stepper motor suitable for high-precision rotation, and each has a power transmission mechanism, thus becoming large and heavy.

[0009] The present invention was made in view of the above-mentioned problems, and the object is to provide a laser line marker that can be miniaturized.

[0010] Solution for solving the problem

[0011] To address the aforementioned issues and achieve the objectives, the laser marking device of the present invention comprises a projection section that projects a laser-formed marking onto an object and a rotating section that supports the projection section and allows it to rotate horizontally. The laser marking device is characterized in that the rotating section comprises: a driven gear that rotates integrally with the projection section; a drive gear that drives the driven gear; a motor driven by a motor control unit; a knob that is manually operated and rotated; a planetary gear mechanism comprising a sun gear, a ring gear, a carrier, and a plurality of pinions; a first drive wheel located on the same axis as the sun gear and arranged throughout 360 degrees and rotating integrally with the sun gear; a second drive wheel with external teeth arranged throughout 360 degrees on the outer circumference of the ring gear; a motor worm gear disposed on the rotational shaft of the motor; and a knob worm gear disposed on the rotational shaft of the knob, wherein the first drive wheel meshes with the motor worm gear, and the second drive wheel meshes with the knob worm gear.

[0012] In the laser marking device of the present invention, a planetary gear mechanism can be applied to two input sections, thus enabling miniaturization.

[0013] Alternatively, with the rotation center of the light-projecting part and the driven gear as a reference, the knob and the knob worm are located on the outer periphery of the planetary gear mechanism, and the motor and the motor worm are located on the inner periphery of the planetary gear mechanism, with a portion overlapping the gear ring when viewed from the direction of the rotation center. Thus, the knob is positioned for easy hand operation, the motor is inconspicuous and centrally located, and the center of gravity remains unbalanced.

[0014] Alternatively, the motor and the motor worm gear may overlap with the drive gear when viewed from the direction of the rotation center. The motor is further positioned closer to the center.

[0015] Alternatively, the knob worm gear can be located on the side closer to the light-projecting part than the motor worm gear. This allows the motor and knob to be positioned in a balanced and appropriate manner for their respective functions.

[0016] Alternatively, the frame can be composed of a first member and a second member that are elastically stressed relative to each other in the rotational direction by an elastic body. An even number of pinions are provided, with one of two adjacent pinions supported by the first member and the other by the second member. Thus, adjacent pinions elastically attract or repel each other, thereby achieving a well-balanced reduction in backlash relative to the sun gear and ring gear.

[0017] Alternatively, it may have a backlash suppression mechanism that suppresses the backlash between the driving gear and the driven gear. Alternatively, the backlash suppression mechanism may be implemented by using a scissor gear to construct the driven gear. With such a backlash suppression mechanism, good responsiveness is obtained.

[0018] If the motor is a DC motor, and a speed suppression mechanism that provides rotational resistance is provided on the rotating shaft of the motor, then the rotation of the motor is stable.

[0019] If the speed suppression mechanism is configured as an elastic body that directly or indirectly abuts against the rotating shaft of the motor, the structure becomes simple.

[0020] If the elastic body directly or indirectly abuts against the front end of the rotating shaft of the motor, it becomes a state in which the motor shaft is simply supported at both ends.

[0021] If the elastomer indirectly contacts the rotating shaft of the motor via a resin material, wear on the rotating shaft can be prevented.

[0022] If the motor is a DC motor and a damping resistor is provided in the drive line, the motor rotation is stable.

[0023] Alternatively, depending on the operating mode, the rotating part can cause the projection part to rotate at an angle of 2 to 6 seconds, thereby achieving high-precision positioning.

[0024] Alternatively, the driving gear and the driven gear may be made of a resin material containing glass fibers. Alternatively, the gears constituting the planetary gear mechanism may be made of a resin material containing glass fibers. Such resin materials have a low coefficient of linear expansion, resulting in less expansion and contraction due to temperature, thus suppressing the longitudinal reference line from shifting over time.

[0025] An encoder is installed on the rotating shaft of the motor, and the signal from the encoder is supplied to the motor control unit, thereby improving the positioning accuracy of the longitudinal reference line.

[0026] Invention Effects

[0027] In the laser marking device of the present invention, a planetary gear mechanism can be applied to two input sections, thus enabling miniaturization. Attached Figure Description

[0028] Figure 1 is a perspective view of a laser line marker according to an embodiment.

[0029] Figure 2 is a schematic perspective view showing the laser line marker and the light receiver that make up the line-laying unit.

[0030] Figure 3 is a three-dimensional view of the rotating part.

[0031] Figure 4 is a perspective view of the drive mechanism and its surrounding parts from a slightly downward angle in the rotating part with the housing removed.

[0032] Figure 5 is a perspective view of the drive mechanism and its surrounding parts taken from an oblique angle in the rotating part with the housing removed.

[0033] Figure 6 is a three-dimensional view obtained by observing the same part as in Figure 4 from the opposite side.

[0034] Figure 7 is an enlarged perspective view of the motor shaft and its surrounding area from the inner diameter side.

[0035] Figure 8 is a bottom view of the drive mechanism and the driven gear.

[0036] Figure 9 is a perspective view of the planetary gear mechanism taken from an oblique angle above the inner diameter with the center C0 as the reference.

[0037] Figure 10 is a perspective view of the planetary gear mechanism taken from the oblique downward side of the outer diameter with the center C0 as the reference.

[0038] Figure 11 is an exploded perspective view of the planetary gear mechanism.

[0039] Figure 12 is an exploded perspective view of the driven gear and bearing.

[0040] Figure 13 is a diagram showing a modified example of the backlash suppression mechanism.

[0041] Figure 14 is a diagram showing the light receiver. Figure 14(a) is a front view, and Figure 14(b) is a top view based on the state of Figure 14(a).

[0042] Figure 15 is a block diagram of the wire feeder unit.

[0043] Figure 16 is a summary flowchart illustrating the processing of the automatic setting mode.

[0044] Figure 17 is a schematic diagram showing the positional relationship between the light-receiving window and the longitudinal reference of the micro-angle rotation segment. Detailed Implementation

[0045] Hereinafter, embodiments of the laser line marker of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to these embodiments.

[0046] Figure 1 is a perspective view showing a laser line marker 10 according to an embodiment of the present invention. Figure 2 is a schematic perspective view showing the laser line marker 10 constituting the line feeder unit 12 and the light receiver 14.

[0047] The laser line marker 10 projects laser-formed lines 16 onto objects such as walls, ceilings, and floors. The lines 16 in Figure 2 are shown as dashed lines, but are actually projected as solid lines. The laser line marker 10 is used not only indoors but also outdoors during the day, therefore the lines 16 are appropriately bright. The lines 16 mainly include a horizontal reference 16a and a vertical reference 16b projected onto the wall, a ground reference 16c projected onto the floor, and a ceiling reference 16d projected onto the ceiling. The two opposing vertical references 16b, the ground reference 16c, and the ceiling reference 16d are continuous, forming a frame line 16e. The two frame lines 16e are orthogonal, forming a large right angle. The projection direction of the frame line 16e can be varied by rotating the projection unit 18 (described later). The horizontal reference 16a is formed around the perimeter in a 360-degree arc. The projection height of the horizontal reference 16a can be adjusted manually or automatically. The laser line marker 10 projects a lower point 16f directly downwards. The lower point 16f differs from the others in that it is a point and becomes the reference point in the floor surface.

[0048] The aforementioned markings 16 may be partially omitted or have a different number depending on the machine model and settings. In the mode where the frame line 16e rotates automatically, the laser marker 10 and the light receiver 14 work together. The length between the laser marker 10 and the light receiver 14 is defined as distance D. The maximum value of distance D, for example, is approximately 15m according to the specifications.

[0049] The laser marking device 10 has a projection section 18 that projects a laser-formed marking line 16 onto an object, and a rotating section 20 that supports the projection section 18 from below and allows it to rotate horizontally. The projection section 18 is capable of infinite rotation. Detachable legs 22 are provided at 120-degree intervals below the rotating section 20. The front ends of the legs 22 are conical, and a length adjustment mechanism is provided in the middle portion of each leg 22.

[0050] The projection unit 18 is generally cylindrical and includes an operation panel 18a at the top, four vertical emission windows 18b angled upwards, multiple horizontal emission windows 18c on the periphery, a battery compartment 18d, and an external power port 18e. The operation panel 18a includes a mode switch, a vertical line switch, a horizontal line switch, and a battery level indicator. The vertical emission windows 18b emit a frame-shaped line 16e. The horizontal emission windows 18c emit a horizontal reference line 16a. The laser marker 10 operates using power supplied from a battery in the battery compartment 18d or from the external power port 18e. A power switch is provided on the back side of the projection unit 18 (not shown in FIG. 1).

[0051] Figure 3 is a perspective view of the rotating part 20. As shown in Figures 1 and 3, in the rotating part 20, a housing 24 having a disc portion 24a, a bulge portion 24b, a leg mounting portion 24c, and a lower cylinder 24d serves as a base. The housing 24 forms an internal space through the cooperation of two upper and lower components. The disc portion 24a is, for example, a disc with a height-to-diameter ratio of approximately 1:4, coaxial with the projection portion 18, and having approximately the same diameter. A bearing 26 is present in the disc portion 24a. The leg mounting portion 24c is the part that mounts the legs 22. The lower cylinder 24d is a hollow cylinder for the projection portion 18 to project the lower point 16f. A level 30 is provided on the side of the disc portion 24a. A control board 34 is provided inside the rotating part 20. For the control board 34, one or more circular or arc-shaped boards are provided in a single layer or multiple layers.

[0052] The bulge 24b bulges to the side and below the disc portion 24a. The lateral bulge 24ba is positioned within an area of ​​approximately 60 degrees relative to the center C0 of the disc portion 24a. The radial width of the lateral bulge 24ba relative to the center C0 is very small compared to the disc portion 24a, for example, about one-third of the radius of the disc portion 24a, similar to the battery box 18d. The drive mechanism 28 is housed inside the bulge 24b. The bulge 24b is very small compared to the overall size of the laser marker 10; in other words, even with the bulge 24b and its internal drive mechanism 28, it has almost no impact on the overall size of the laser marker 10. The lower bulge 24bb of the bulge 24b is located in the space formed between the three legs 22, effectively utilizing so-called ineffective space.

[0053] A knob 32, which is manually operated, protrudes from one circumferential end of the side bulge 24ba. The knob 32 is located on the extended tangent line of the outer periphery of the disc portion 24a, with a gap sufficient to allow a finger to enter between it and the circumferential surface of the disc portion 24a. The knob 32 is formed with an appropriate diameter and length for easy rotation. The knob 32 is moderately separated from the floor surface for easy rotation. It should be noted that although the knob 32 is outside the side bulge 24ba, it is also considered part of the drive mechanism 28. Inside the rotating part 20, a driven gear 36 is provided, rotating coaxially with the bearing 26. The driven gear 36 is, for example, about 2 / 3 the diameter of the disc portion 24a, and is driven by the drive mechanism 28. The knob 32 is used to manually rotate the projector 18; it is lightweight, and by setting a relatively large reduction ratio based on the reducer 50 (described later), it can be operated with good precision and light force.

[0054] The projector 18 is pressed against the bearing 26 by a designated pressing plate and rotates integrally with the bearing 26 and the driven gear 36. The projector 18 can be rotated while sliding relative to the bearing 26 by direct operation by the user, and can also be rotated by the knob 32 and the motor 42 via the reducer 50.

[0055] Figure 4 is a perspective view of the drive mechanism section 28 and its surrounding parts from a slightly downward angle within the rotating section 20 with the housing 24 removed. Figure 5 is a perspective view of the drive mechanism section 28 and its surrounding parts from a slightly upward angle within the rotating section 20 with the housing 24 removed. Figure 6 is a perspective view of the same part as in Figure 4 from the opposite side. Figure 7 is an enlarged perspective view of the motor shaft 42b and its surrounding parts from the inner diameter side. In the description of the drive mechanism section 28, the side closer to the center C0 is defined as the inner diameter side, and the side farther from the center C0 is defined as the outer diameter side. Furthermore, the radial and circumferential directions are defined with reference to the center C0.

[0056] As shown in Figures 4 and 5, the drive mechanism 28 is configured with a retainer 38 serving as a base. The retainer 38 is a frame shape with a radial opening and has a mounting plate 38a fixed to the housing 24, two support columns 38b extending downward from the mounting plate 38a, a gear protector 38c protruding upward from the mounting plate 38a, and a lower cover plate 38d. The mounting plate 38a, support columns 38b, and gear protector 38c are integral structures, and the lower cover plate 38d is threadedly fixed to the two support columns 38b. The gear protector 38c is a small, low-profile cylindrical shape with an opening on its inner diameter side.

[0057] Mounting plate 38a has an arcuate portion 38aa along the outer periphery of driven gear 36 and a bracket fixing portion 38ab protruding from the arcuate portion 38aa toward the outer diameter side. The two ends of the arcuate portion 38aa are threaded to the housing 24, and a support column 38b is erected nearby thereon. The arcuate portion 38aa is located within the area of ​​the disc portion 24a of the housing 24 (see Figure 8), and the bracket fixing portion 38ab enters the lateral bulge 24ba (see Figure 8).

[0058] A knob support bracket 40 is fixed to the lower surface of the bracket fixing part 38ab. The knob support bracket 40 is formed in a "コ" shape, slightly longer in the circumferential direction and having downwardly bent pieces 40a at both ends. The bent pieces 40a are moderately low, for example, about half the length of the support column 38b. Shaft holes are formed in the two bent pieces 40a to support the knob shaft 32a. The knob shaft 32a is a shaft that rotates integrally with the knob 32, but the knob 32 can be attached and detached relative to the knob shaft 32a. A knob worm 32b is provided in the portion between the two bent pieces 40a in the knob shaft 32a. In the figures, the knob worm 32b, the motor worm 42c (described later), and the first drive wheel 54 are shown in a mode where the teeth are omitted. The knob worm 32b and the motor worm 42c have one or two slots and have a self-locking function, preventing the worm side from being driven from the wheel side.

[0059] As shown in Figures 6 and 7, one end of the lower cover plate 38d on the inner diameter side (the right side in Figure 6) is bent downwards to form a motor fixing plate 38da. The motor fixing plate 38da is formed along the vertical and radial directions, and its height is, for example, about half the height of the support column 38b. A spring hole 38db, which is slightly longer in the radial direction, is formed in the lower cover plate 38d at a position that is slightly separated from the motor fixing plate 38da in the circumferential direction.

[0060] The end face of the generally cylindrical body 42a of the motor 42 is threadedly fixed to the motor mounting plate 38da. The motor 42 is, for example, a small DC motor. The end face of the body 42a is formed with the same shape as the motor mounting plate 38da. The motor shaft 42b of the motor 42 protrudes from the end face of the body 42a through the hole in the motor mounting plate 38da. The body 42a and the motor shaft 42b are generally circumferential. The front end 42ba of the motor shaft 42b is hemispherical and protrudes above the spring hole 38db. A motor worm gear 42c is provided on the motor shaft 42b.

[0061] A sensor box 44 is provided on the side of the motor 42 opposite to the side protruding from the motor shaft 42b. The width of the sensor box 44 along the direction of the motor shaft 42b is about half that of the main body 42a. The cross-section of the sensor box 44 orthogonal to the motor shaft 42b is a rectangle slightly larger than that of the main body 42a. The sensor box 44 is formed as a whole in a flat shape. Inside the sensor box 44 are a rotary encoder 44a, the drive wire of the motor 42, etc. The rotary encoder 44a is a circular plate with a slit mounted on the motor shaft 42b. It outputs pulse signals corresponding to the rotational speed and angle of the motor 42 by transmitting or reflecting infrared light. The slit of the rotary encoder 44a is composed of phase A and phase B that are offset from each other. By optically reading each phase, the rotation angle and rotation direction can be detected. The rotary encoder 44a is used for the rotation angle control of the projection unit 18, but it can also be used for adjusting the rotational speed at the time of product shipment.

[0062] In the laser line marker 10, there is an automatic setting mode in which the projection part 18 is automatically rotated by the motor 42 to position the longitudinal reference 16b. The resolution of the slit of the rotary encoder 44a is set according to the maximum application distance between the laser line marker 10 and the light receiver 14 in this mode, the characteristics of the laser optical system, the required positioning accuracy, and the reduction ratio of the reducer 50.

[0063] A metal leaf spring (elastic body) 46 is provided on the lower cover plate 38d. The leaf spring 46 is L-shaped and has a relatively wide fixing plate 46a and a relatively narrow shaft abutment plate 46b. The fixing plate 46a is fixed to the lower surface of the lower cover plate 38d, and the shaft abutment plate 46b protrudes upward through the spring hole 38db. The width of the shaft abutment plate 46b is slightly wider than the front end 42ba of the motor shaft 42b, and by elastically pressing the front end 42ba, a force is applied to the motor shaft 42b towards the body 42a. That is, the shaft abutment plate 46b has the function of a speed suppression mechanism that imparts rotational resistance to the motor shaft 42b.

[0064] The shaft abutment piece 46b, by abutting against the front end 42ba, can easily support both ends of the motor shaft 42b, thereby reducing shaft runout. However, it can also connect to other parts besides the front end 42ba, depending on the conditions. The speed suppression mechanism for the motor shaft 42b is not limited to the leaf spring 46; for example, a coil spring could also be used. The shaft abutment piece 46b indirectly abuts against the front end 42ba via a small and thin resin sheet 48. The resin sheet 48, for example, is a nylon sheet and is bonded to the shaft abutment piece 46b. By clamping the resin sheet 48, the shaft abutment piece 46b and the front end 42ba will not wear, and the shaft runout is further reduced by the front end 42ba abutting against the resin sheet 48 while slightly concave. However, depending on the conditions, the resin sheet 48 can be omitted, and the shaft abutment piece 46b can directly abut against the front end 42ba. The front end 42ba is hemispherical, and the resin sheet 48, or the abutment portion relative to the shaft abutment piece 46b, is microscopically formed as a circle, suitable for rotation.

[0065] As shown in Figures 4-6, the drive mechanism 28 includes a reducer 50. The reducer 50 is based on a central shaft 52, with a first drive wheel 54 externally mounted on the lower part of the central shaft 52, a drive gear 56 externally mounted on the upper part of the central shaft 52, and a planetary gear mechanism 58 disposed between them. Two opposing D-shaped cut portions 52a are formed on the lower part of the central shaft 52 (see Figure 10). The central hole of the first drive wheel 54 has a flat portion that matches the two D-shaped cut portions 52a, and the first drive wheel 54 rotates integrally with the central shaft 52. The first drive wheel 54 is the first input portion and meshes with the motor worm gear 42c. The first drive wheel 54 and the planetary gear mechanism 58 are subjected to forces in the vertical direction by a helical spring 55a and a pair of upper and lower circular plates 55b (also see Figure 10). The second drive wheel 60, whose external teeth form the gear ring 66 of the planetary gear mechanism 58 housing, is the second input portion and meshes with the knob worm gear 32b. The drive gear 56 is integrated with a portion of the carrier 70 described later, and forms an output part that meshes with the driven gear 36.

[0066] The planetary gear mechanism 58 is disposed between two supports 38b. The lower end of the central shaft 52 is embedded in the shaft hole formed by the lower cover plate 38d and is supported by the shaft, while the upper end of the central shaft 52 is embedded in the shaft hole formed by the gear protector 38c and is supported by the shaft.

[0067] The planetary gear mechanism 58 has two input sections: a first drive wheel 54 and a second drive wheel 60. However, the layout requirements for the motor 42 and the knob 32 that input to them differ. Specifically, the motor 42 needs to be compactly housed in an inconspicuous location inside the housing 24, while the knob 32 needs to be positioned on the outside of the housing 24 in a moderately conspicuous and easily operable location. These requirements are met in the laser marker 10 as follows.

[0068] The knob worm gear 32b, which meshes with the second drive wheel 60 at the middle height in the reducer 50, is located on the side higher than the motor worm gear 42c, which meshes with the first drive wheel 54 below, i.e., closer to the projection section 18. Correspondingly, the knob 32 is located higher than the motor 42. Therefore, the knob 32 is in a relatively high position, ensuring a safe distance from the floor for easy operation. The motor 42 is in a relatively low position, making it easy to position below the disc section 24a. The motor 42 is heavier than the knob 32, and by being housed in the lower bulge 24bb, the overall center of gravity of the laser marker 10 is lowered, thus stabilizing the system. In addition, the heavier motor 42 is located at least within the disc section 24a (see Figure 8), preventing the overall center of gravity of the laser marker 10 from becoming extremely unbalanced.

[0069] Figure 8 is a bottom view of the drive mechanism 28 and the driven gear 36. The lower cover 38d and leaf spring 46 are omitted in Figure 8, and the housing 24 is shown using imaginary lines. The first drive wheel 54 has a smaller diameter than the second drive wheel 60, for example, about 2 / 5 of its diameter.

[0070] With center C0 as a reference, the motor worm gear 42c engages with the inner diameter side of the first drive wheel 54, causing the motor 42 and sensor box 44 to converge within the area of ​​the disk portion 24a when viewed from the bottom side (viewed from the direction of the rotation center). Furthermore, the diameter of the first drive wheel 54 is small, so the motor worm gear 42c engaging with it is not positioned excessively close to the inner diameter side; in this embodiment, it is positioned approximately at the same level as the outer circumference of the driven gear 36. Moreover, the motor shaft 42b, main body 42a, and sensor box 44 are arranged approximately circumferentially without significantly entering the inner diameter side. Therefore, the lower bulge 24bb (see Figure 3) housing the motor 42, sensor box 44, and first drive wheel 54 becomes compact, with no wasted space inside the housing.

[0071] With center C0 as a reference, the knob worm 32b engages with the outer diameter side of the second drive wheel 60. The diameter of the second drive wheel 60 is relatively large and protrudes slightly compared to the range of the disc portion 24a. By engaging the motor worm 42c in this part, the knob 32 protrudes tangentially and is positioned in a position that is easy to operate.

[0072] In this way, the motor worm gear 42c and the knob worm gear 32b are staggered in the vertical and radial directions, so that the motor 42 and the knob 32 can be well balanced and positioned in their respective functional positions.

[0073] Next, the planetary gear mechanism 58 will be described.

[0074] Figure 9 is a perspective view of the planetary gear mechanism 58 taken from an obliquely upward view of the inner diameter side with reference to center C0. Figure 10 is a perspective view of the planetary gear mechanism 58 taken from an obliquely downward view of the outer diameter side with reference to center C0. Figure 11 is an exploded perspective view of the planetary gear mechanism 58. The gear ring 66 is omitted in Figure 11. In the description of the planetary gear mechanism 58, the side closer to the center C1 of the central shaft 52 is designated as the inner diameter side, and the side farther from the center C1 of the central shaft 52 is designated as the outer diameter side.

[0075] As shown in Figures 9 and 10, the planetary gear mechanism 58 is configured with a central shaft 52 as the reference and includes a sun gear 64, a ring gear 66, four pinions 68, and a carrier 70. The sun gear 64, ring gear 66, and pinions 68 have the same tooth width and are aligned vertically. The sun gear 64, ring gear 66, and pinions 68 are spur gears, but they could also be helical gears, etc.

[0076] The sun gear 64 is relatively small and is integrally formed approximately in the middle relative to the central shaft 52. The lower surface of the sun gear 64 is positioned by contact with the flange 52b. The ring gear 66 has internal teeth and is integrally formed with the externally toothed second drive wheel 60. Hereinafter, the internal tooth portion of the ring gear 66 is shown. The ring gear 66 is relatively large and, together with the externally toothed second drive wheel 60, forms the outer housing of the planetary gear mechanism 58. The lower surface of the ring gear 66 is covered by a cover 66b (see Figure 4). Four pinions 68 are arranged at equal angles of 90 degrees between the sun gear 64 and the ring gear 66, and mesh with both the sun gear 64 and the ring gear 66. The number of pinions 68 can also be 2, 3, or 5 or more.

[0077] The second drive wheel 60 is movable vertically relative to the central shaft 52, and is free in the vertical direction. However, strictly speaking, the sun gear 64 acts as a limiter in the vertical direction, so it is only free in the downward direction. When the knob worm gear 32b rotates, the second drive wheel 60 moves vertically while rotating, and is thus pressed by the aforementioned coil spring 55a as its pressing element. Therefore, the rotational transmission loss from the knob 32 to the projection part 18 is eliminated.

[0078] As shown in Figures 10 and 11, the carrier 70 is composed of a first component 72 and a second component 74. The first component 72 is in the shape of a circular plate and has an integrally formed drive gear 56 protruding from its upper surface. The lower surface of the first component 72 has a recess 72a that runs radially through the first component 72, four generally triangular prism-shaped support portions 72b that protrude upwards outside the recess 72a, and a fitting cylinder 72d that protrudes downwards around the central hole 72c. The support portions 72b are positioned to separate the four pinions 68. The central hole 72c allows the central shaft 52 to pass through. The peripheral edge of the first component 72 is embedded in an annular step 66a (see Figure 9) in the upper surface of the gear ring 66, thereby supporting the gear ring 66 for free rotation.

[0079] The recess 72a has an arcuate portion 72aa concentric with the fitting cylinder 72d, a groove 72ab formed circumferentially near both ends, and a spring seat recess 72ac formed at both ends in a clockwise direction as shown in FIG11. A spring 76 is inserted into the groove 72ab.

[0080] The second component 74 is shaped to be embedded in the recess 72a, and has a central annular portion 74a and rotating pieces 74b protruding radially to both sides. The second component 74 is embedded in the fitting cylinder 72d through the annular portion 74a, and can rotate slightly within the width of the recess 72a with reference to the center C1.

[0081] The two rotating plates 74b have protrusions 74ba on the clockwise side of their ends, as shown in FIG11, circumferential grooves 74bb formed on the upper surface of their ends, and spring seat plates 74bc protruding downward from the counterclockwise end of the grooves 74bb. In FIG11, a portion of the grooves 74bb and spring seat plates 74bc is shown in cross-section for ease of understanding. The protrusions 74ba are embedded in the grooves 72ab. The grooves 74bb and 72ab together form the receiving space for the spring 76.

[0082] Four pinion shafts 70a protrude from the lower surface of the carrier 70. The pinion shafts 70a are positioned to support the pinion 68. Two of the four pinion shafts 70a are located in the first member 72, opposite to the fitting cylinder 72d, and the remaining two are located in the second member 74, opposite to the annular portion 74a.

[0083] Four pinions 68 are arranged at equal angles (90 degrees in this case) relative to the sun gear 64 and the ring gear 66. Therefore, the line connecting the two pinion shafts 70a located at opposite positions sandwiching the fitting cylinder 72d is orthogonal to the line connecting the two pinion shafts 70a located at opposite positions sandwiching the annular portion 74a. When the first member 72 and the second member 74 are in such relative positions, the two springs 76 are elastically compressed by the wall of the spring seat recess 72ac and the spring seat plate 74bc, respectively. Thus, the first member 72 and the second member 74 are elastically forceped relative to each other in the rotational direction. In the example of Figure 11, the first member 72 is forceped relative to each other in the clockwise direction, and the second member 74 is forceped relative to each other in the counterclockwise direction.

[0084] As described above, in the planetary gear mechanism 58, the first drive wheel 54 is the first input section, the second drive wheel 60 is the second input section, and the drive gear 56 is the output section, forming a 2-input, 1-output type. The first drive wheel 54 of the first input section, together with the motor worm 42c, constitutes a worm gear mechanism and rotates along with the rotation of the motor worm 42c. Conversely, even if a rotational torque is applied to the first drive wheel 54, the motor worm 42c will not rotate due to a self-locking effect. The second drive wheel 60 of the second input section, together with the knob worm 32b, constitutes a worm gear mechanism and rotates along with the rotation of the knob worm 32b. Conversely, even if a rotational torque is applied to the second drive wheel 60, the knob worm 32b will not rotate due to a self-locking effect.

[0085] When the motor worm 42c, the first drive wheel 54, the central shaft 52, and the sun gear 64 rotate under the action of the motor 42, the second drive wheel 60 is fixed due to its self-locking action. Therefore, the pinion 68 rotates on its own axis 70a and revolves around the center C1 based on the rotation of the sun gear 64 and the fixed state of the gear ring 66.

[0086] When the knob 32 rotates the worm gear 32b and the second drive wheel 60, the first drive wheel 54 is fixed due to its self-locking action. Therefore, the pinion 68 rotates on its own axis 70a and revolves around the center C1, based on the fixed state of the sun gear 64 and the rotation state of the gear ring 66.

[0087] Therefore, as the pinion 68 revolves, the carrier 70 and the drive gear 56 rotate at a reduced speed, which can drive the driven gear 36.

[0088] In this planetary gear mechanism 58, two input sections can be applied through a single mechanism, thus enabling miniaturization, and the two input sections do not interfere with each other. The self-locking mechanism eliminates the need for a special brake, ensuring that the self-locking of the other input section does not become a load resistance when viewed from one input side, suppressing power consumption on the motor 42 side, and providing light and easy operation on the knob 32 side. The first drive wheel 54, serving as the first input section, and the drive gear 56, serving as the output section, are coaxially configured, simplifying the layout. The planetary gear mechanism 58 can rotate indefinitely.

[0089] It should be noted that, in this embodiment, the laser marker 10 can be manually operated by sliding relative to the bearing 26 when roughly aligning the projection section 18, but the gears of the reducer 50 do not rotate during this rotation. If the projection section 18 is fixed relative to the bearing 26 and cannot slide, it can also be configured with a non-locking structure (e.g., making the groove of the knob worm gear 32b three-slot structure) via the reducer 50 mechanism.

[0090] Furthermore, there is an even number of pinions 68 (four in this embodiment), and the pinion shafts 70a of adjacent pinions 68 are separately disposed on the first member 72 and the second member 74, which are elastically forceped relative to each other in the rotational direction by the spring 76. Therefore, two adjacent pinions 68 elastically attract or repel each other, thus achieving a well-balanced reduction in backlash relative to the sun gear 64 and the ring gear 66, resulting in good responsiveness.

[0091] Figure 12 is an exploded perspective view of the driven gear 36 and the bearing 26. The driven gear 36 is formed as a scissors gear (backlash reduction mechanism) consisting of a first gear 78 and a second gear 80. In Figure 12, the first gear 78 is shown in a reverse orientation relative to the second gear 80 and the bearing 26.

[0092] The first gear 78 has an annular fitting cylinder 78a protruding upward from its inner circumference, fixing portions 78b spaced at 90-degree intervals around the fitting cylinder 78a, and two grooves 78c formed circumferentially on its upper surface. The first gear 78 is embedded in the lower part of the bearing 26 and fixed by the fixing portions 78b. The vertical width of the fitting cylinder 78a is approximately the same as the tooth width of the second gear 80, and the upper surface of the fitting cylinder 78a abuts against a portion of the bearing 26 to ensure space for insertion of the second gear 80. The two grooves 78c are formed at opposite positions on the upper surface at the midpoints of the two fixing portions 78b. A small spring seat 78ca protrudes upward from one end of the groove 78c. A spring 82 is inserted into the groove 78c.

[0093] The lower surface of the second gear 80 has two circumferentially formed grooves 80b. The two grooves 80b are formed in opposite positions at positions that substantially correspond to the groove 78c of the first gear 78. A small spring seat 80ba protrudes downward from one end of the groove 80b. The grooves 80b and 78c together form a receiving space for the spring 82.

[0094] The first gear 78 and the second gear 80 have the same module and the same number of teeth. When combined, the two springs 82 are elastically compressed by the spring seats 78ca and 80ba, respectively. Thus, the first gear 78 and the second gear 80 are elastically forced relative to each other in the rotational direction. When the driven gear 36 is engaged with the drive gear 56, the teeth of the lower first gear 78 and the upper second gear 80 elastically extend circumferentially, making gapless contact with the adjacent teeth on both sides of the drive gear 56, thereby reducing backlash and achieving good responsiveness. However, depending on the design conditions, the driven gear 36 can also be constructed using a simple single gear that is not a scissor gear.

[0095] Figure 13 is a diagram showing a modified example of the backlash suppression mechanism. The backlash suppression mechanism between the driven gear 36 and the drive gear 56 can also be, for example, the mechanism shown in Figure 13, except that the driven gear 36 is a scissor gear.

[0096] The backlash suppression mechanism 84 in this modified example has a small pulley 84a that rotates coaxially and integrally with the drive gear 56, a large pulley 84b that rotates coaxially and integrally with the driven gear 36, a belt 84c mounted between the small pulley 84a and the large pulley 84b, and a tensioning pulley 84d that presses the belt 84c from the side. The belt 84c is a V-belt, a flat belt, etc. Because the belt 84c is pressed from the side by the tensioning pulley 84d, a tension force is applied to the belt 84c, and the reducer 50, including the drive gear 56, is elastically forceped along this radial direction, thereby reducing the backlash between the drive gear 56 and the driven gear 36. The backlash suppression mechanism 84 also serves as a deceleration and driving force transmission mechanism; in this case, the drive gear 56 and the driven gear 36 can be omitted.

[0097] The gears (including the worm gear mechanism) constituting the reducer 50, which includes the planetary gear mechanism 58, are made of a resin material (e.g., polyacetal) containing glass fiber. Such a resin material has a low coefficient of linear expansion, resulting in minimal expansion and contraction due to temperature, thus suppressing the movement of the longitudinal reference 16b over time. Furthermore, the driven gear 36, being the final stage driving the projection section 18, is particularly effective in suppressing movement of the longitudinal reference 16b due to temperature changes by using a resin material containing glass fiber. This suppression of movement of the longitudinal reference 16b is particularly noticeable given its high positioning accuracy and long-term use. Moreover, by using a resin material, each gear offers advantages over metal materials, such as being lightweight, inexpensive, and having good formability.

[0098] Next, the structure and function of the line feeder unit 12 will be explained. The line feeder unit 12 consists of a laser line marker 10 and a light receiver 14. The mechanical structure of the laser line marker 10 is as described above.

[0099] Figure 14 is a diagram showing the light receiver 14. Figure 14(a) is a front view, and Figure 14(b) is a top view based on the state shown in Figure 14(a). In Figure 14(a), the light receiver 14 is shown horizontally placed on the floor G. In the following description, the vertical and horizontal orientations are based on the horizontal position shown in Figure 14(a). The light receiver 14 is a slightly elongated rectangle when viewed from the front and is sized for one-handed operation. The light receiver 14 has a transmitting function relative to the laser marker 10 and can be operated as a remote control.

[0100] The light receiver 14 has a rectangular light-receiving window 86 near one end and a plate 88 near the other end. The plate 88 is a component for fixing to a specified retainer (not shown). Above the light-receiving window 86 are a right proximity LED 90a, a left proximity LED 90b, and a matching LED 90c. Inside the light-receiving window 86, a right sensor (light-receiving element) 92a and a left sensor (light-receiving element) 92b are arranged in a left-right division. The right sensor 92a and the left sensor 92b are, for example, photoelectric sensors, and have a certain width in the left-right direction in FIG. 14(a). The boundary between the right sensor 92a and the left sensor 92b is a target line 92c, which becomes the target position of the longitudinal reference 16b.

[0101] Between the light-receiving window 86 and the plate 88 are provided a power switch 14a, a line switch 14b, a connection display LED 14c, a brightness switch 14d, a volume switch 14e, and a mode switch 14f. The power switch 14a turns the power to the light receiver 14 on and off. The line switch 14b turns the projection of the mark 16 on and off. The brightness switch 14d adjusts the brightness of the mark 16. Furthermore, if the power switch 14a is pressed while the line switch 14b and brightness switch 14d are pressed, wireless communication between the light receiver 14 and the laser mark 10 is established, and the connection display LED 14c illuminates. The volume switch 14e adjusts the volume of the buzzer, etc. The mode switch 14f selects between two modes for rotating the projection section 18 of the laser mark 10. Among the modes for rotating the projection section 18 are an automatic setting mode and an infinite rotation mode.

[0102] When using the automatic setting mode, the light receiver 14 is positioned horizontally so that the target position of the caliper target line 92c is matched with the target position of the longitudinal reference 16b (see also Figure 2). The light receiver 14 can also be reversed left and right as shown in Figure 14(a). When using the infinite rotation mode, the light receiver 14 can also be operated by hand.

[0103] A forward rotation switch 14g and a reverse rotation switch 14h are respectively provided on the upper surface (Figure 14(b)) and lower surface of the light receiver 14. In the infinite rotation mode, if the forward rotation switch 14g or the reverse rotation switch 14h is pressed, the light projector 18 will rotate forward or reverse. If the forward rotation switch 14g or the reverse rotation switch 14h is pressed again, it will stop.

[0104] Figure 15 is a block diagram of the line-dispensing unit 12. Inside the light receiver 14, a light receiver computer 94b, two input interfaces 94c and 94d, and a transmitting module (transmitter unit) 94e are mounted on the light receiver substrate 94a. The input interfaces 94c and 94d perform prescribed transformations on the signals from the right sensor 92a and the left sensor 92b and supply them to the light receiver computer 94b. Based on the signals supplied via the input interfaces 94c and 94d, the light receiver computer 94b can identify whether the longitudinal reference 16b (schematically shown by an imaginary line) is illuminating one of the right sensor 92a or the left sensor 92b, or not illuminating either. The light receiver computer 94b performs judgment processing based on these signals and transmits signals to the laser marker 10 via the transmitting module 94e. The transmitting module 94e performs wireless transmission to the laser marker 10 according to a prescribed specification. This specification is, for example, Bluetooth (registered trademark). Communication between the light receiver 14 and the laser marker 10 is essentially unidirectional.

[0105] An accelerometer 94f is provided on the light receiver 14, and the light receiver computer 94b can identify whether the light receiver 14 is in a horizontal or vertical position. Although not shown in the figure, switches, lights, buzzers, etc. are connected in a manner that allows input and output through the light receiver computer 94b. Some or all of the right sensor 92a, left sensor 92b, accelerometer 94f, switches, lights, buzzers, etc., can also be mounted on the light receiver substrate 94a.

[0106] The laser line marker 10 includes a projection section 18 with a projection section substrate 96a and a wireless transmission substrate 96b. The projection section substrate 96a houses a projection section computer 96c, a receiving module 96d, and a laser irradiation section 96e. The receiving module 96d receives wireless data from the transmission module 94e and supplies it to the projection section computer 96c. The projection section computer 96c is connected to an operation panel 18a (see Figure 1), and based on the signals supplied from the transmission module 94e and the operation of the operation panel 18a, the projection section computer 96c drives the laser irradiation section 96e to project and stop the line 16. Furthermore, the projection section computer 96c transmits a predetermined signal to the rotating section 20 via the wireless transmission substrate 96b.

[0107] An infrared light-emitting unit 96f is mounted on the wireless transmission board 96b, and the signal received from the light-emitting unit computer 96c is transmitted to the rotating unit 20 using infrared light. This transmission method is, for example, based on near-infrared pulse position modulation.

[0108] In the rotating section 20, a rotating section computer 98a and a photodiode 98b are mounted on the control board 34. Additionally, a driver 98c and a damping resistor 98d are provided in the rotating section 20. The photodiode 98b converts the light signal received from the infrared emitting unit 96f into an electrical signal and supplies it to the rotating section computer 98a. The rotating section computer 98a drives the driver 98c to rotate the motor 42 based on signals supplied from the light receiver computer 94b and the light emitter computer 96c via the infrared emitting unit 96f, and signals received from the rotary encoder 44a. The driver 98c converts rotation and stop signals into electrical signals for the motor 42 to rotate, and also has a safety function to stop the motor 42 in case of an abnormality. The motor 42 rotates continuously at a rotational speed that balances the rotational load and current by continuously supplying power.

[0109] Between the driver 98c and the motor 42, damping resistors 98d are inserted into the two drive lines respectively. Utilizing the voltage drop generated by damping, the initial rotational speed, which consumes the most power, can be started with a gradual acceleration. The damping resistors 98c can be combined into one, but by dividing them into two, the heat generated by each can be suppressed, and thermal balance becomes better. The driver 98c and damping resistors 98d can be located in the sensor box 44 or on the control board 34.

[0110] Next, the automatic setting mode of the line-laying unit 12 will be explained. The automatic setting mode automatically aligns the longitudinal reference 16b with the target line 92c between the right sensor 92a and the left sensor 92b. Before this process, the automatic setting mode is selected in advance using the mode switch 14f, and the receiver 14 is placed horizontally on the floor G such that the target line 92c is positioned at the target position of the longitudinal reference 16b. Additionally, the projection unit 18 projects at least one longitudinal reference 16b. When manually adjusting the position of the longitudinal reference 16b using the knob 32, the user sometimes has to repeatedly move back and forth between the wall and the laser line marker 10 to confirm the illumination position of the longitudinal reference 16b. However, in the automatic setting mode, the laser line marker 10 and the receiver 14 work together, eliminating the need for back-and-forth movement to set the target position of the longitudinal reference 16b, or reducing the number of back-and-forth movements.

[0111] Figure 16 is a summary flowchart illustrating the processing of the automatic setting mode. Steps S101-S108 in the left part of Figure 16 are processes performed by the light receiver computer 94b on the light receiver 14 side, while steps S201-S204 in the right part are processes performed by the rotation unit computer 98a on the laser marker 10 side. The dashed arrows in Figure 16 represent signals transmitted from the light receiver computer 94b to the rotation unit computer 98a, which are relayed by the projection unit computer 96c inside the laser marker 10.

[0112] Figure 17 is a schematic diagram showing the positional relationship between the light-receiving window 86 of the micro-angle rotation element and the longitudinal reference 16b. In Figure 17, the direction from right to left is defined as forward rotation, and the opposite direction is defined as reverse rotation.

[0113] The automatic setting mode is divided into a wide-angle rotation stage, which corresponds to the first stage of steps S102 to S104, and a small-angle rotation stage, which corresponds to the second stage of steps S105 to S107. However, these are names for ease of understanding, and there are also cases where the rotation angle of the wide-angle rotation stage is narrow.

[0114] In step S101, the user starts the automatic setting mode by pressing the forward switch 14g or the reverse switch 14h of the light receiver 14.

[0115] In step S102, a motor rotation indication is wirelessly sent to the laser pointer 10. This transmitted signal includes an indication of the start of rotation of the motor 42 and its rotation direction. The rotation direction is determined by which of the forward switch 14g and the reverse switch 14h is pressed.

[0116] In step S201, the drive motor 42 in the laser line marker 10 is rotated in the indicated direction, thereby causing the longitudinal reference 16b illuminated by the projection section 18 to begin moving.

[0117] When the longitudinal reference 16b is detected by either the right sensor 92a or the left sensor 92b on the light receiver 14 side ("Yes") after processing in step S103, the process proceeds to step S104; otherwise, the process enters a light reception wait state. If multiple longitudinal references 16b exist, the process proceeds to step S104 when the first longitudinal reference 16b is detected on either side. In the light receiver 14, when the right sensor 92a detects the longitudinal reference 16b, the right proximity LED 90a is illuminated; when the left sensor 92b detects the longitudinal reference 16b, the left proximity LED 90a is illuminated.

[0118] In step S104, the light receiver 14 wirelessly sends a motor temporary stop instruction to the laser pointer 10, and the laser pointer 10 temporarily stops the motor 42 and the light-projecting unit 18 based on the wireless reception (S202). During the wide-angle rotation phase, the light-projecting unit 18 rotates relatively quickly. Therefore, when the distance D (see Figure 2) is long, the longitudinal reference 16b moves at a certain speed, and the light-projecting unit 18 has inertial force. In this case, even if it transitions to a small-angle rotation phase, high-precision angle control is not possible. Therefore, in this embodiment, when either the right sensor 92a or the left sensor 92b initially detects the longitudinal reference 16b, a temporary stop signal is sent before transitioning to a small-angle rotation phase, causing the motor 42 to temporarily stop.

[0119] From step S105 onwards, the process becomes a small-angle rotation phase. In this phase, after either the right sensor 92a or the left sensor 92b initially detects the longitudinal reference 16b, the laser marker 10, based on the transmitted signal received from the photodetector 14, rotates the encoder 44a by repeatedly processing the judgment from step S106 and outputting a predetermined number of pulses to cause the motor 42 to rotate forward or reverse until the longitudinal reference 16b is positioned on the target line 92c. Furthermore, the number of pulses is preset, initially a relatively large number, decreasing and reversing the rotation of the motor 42 each time the longitudinal reference 16b crosses the target line 92c. The pulse count is, of course, in the range of 1 or higher, not 0.

[0120] Specifically, in step S105, a minute rotation indication of the motor is wirelessly sent to the laser marker 10. This transmitted signal includes an indication of the rotation direction of the motor 42 and the number of pulses corresponding to the rotational displacement angle. Regarding the rotation direction, it is set to forward rotation when the right sensor 92a detects the longitudinal reference 16b, and to reverse rotation when the left sensor 92b detects the longitudinal reference 16b. In the example shown in Figure 17, the initial value of the pulse number is set to 10, and then decreases to 4, 3, and 2 each time the longitudinal reference 16b crosses the target line 92c. The rectangular waveform at the bottom of Figure 17 schematically illustrates the rectangular waveform of the pulses output by the rotary encoder 44a. However, the relative width of the pulses to the light-receiving window 86 can be changed according to the distance D and the angle of the light receiver 14.

[0121] Referring to Figure 17 for further explanation. In the initial stage of the small-angle rotation, the longitudinal reference 16b is located on line L1 to the right of the right sensor 92a. The position of this line L1 can change depending on the distance D, etc. When the distance D is long, the longitudinal reference 16b, which rotates forward due to overshoot, may sometimes cross the target line 92c, but since the right sensor 92a and the left sensor 92b have a moderate lateral width, they will not cross the left end of the left sensor 92b.

[0122] In step S203, the laser marker 10, based on the signal sent in step S105, causes the motor 42 to rotate forward until the rotary encoder 44a outputs 10 pulses. Line L1 is shifted in the forward direction by the amount of 10 pulses to become line L2. It should be noted that the number of pulses can also be counted based on either phase A or phase B, and the reference phase can be changed during forward and reverse rotation.

[0123] In step S106 (line alignment determination), the light receiver 14 determines whether the longitudinal reference 16b is aligned with the target line 92c. If they are aligned, the process proceeds to step S107 ("Yes"); otherwise, it returns to step S105. This determination is set as alignment if neither the right sensor 92a nor the left sensor 92b detects the longitudinal reference 16b, or if the light intensity is very low.

[0124] L2 is detected by the right sensor 92a, and therefore an instruction is sent from the light receiver 14 to the laser line marker 10 in a forward rotation of 10 pulses. When the longitudinal reference 16b shifts in the forward rotation direction by 10 pulses, it becomes line L3. Since L3 is detected by the left sensor 92b, it crosses the target line 92c, and an instruction is sent from the light receiver 14 in a reverse rotation of 4 pulses. When the longitudinal reference 16b shifts in the reverse rotation direction by 4 pulses, it becomes line L4. Since L4 is detected by the left sensor 92b, an instruction is sent from the light receiver 14 to the laser line marker 10 in a reverse rotation of 4 pulses. When the longitudinal reference 16b shifts in the reverse rotation direction by 4 pulses, it becomes line L5. Since L5 is detected by the right sensor 92a, it crosses the target line 92c, and an instruction is sent from the light receiver 14 in a forward rotation of 3 pulses. When the longitudinal reference 16b shifts in the forward rotation direction by 3 pulses, it becomes line L6. L6 is detected by the left sensor 92b, thus crossing the target line 92c, and an indication is issued from the photodetector 14 in the form of a reverse 2-pulse signal. When the longitudinal reference 16b is displaced in the reverse direction by the amount of 2 pulses, it becomes line L7.

[0125] Since line L7 and the target line 92c are within the same range, the judgment in step S106 becomes "yes" and proceeds to step S107. The matching LED 90c is then illuminated in the light receiver 14.

[0126] In step S107, the same judgment process as in step S106 is performed. Furthermore, if the longitudinal reference 16b aligns with the target line 92c for a specified number of consecutive times (or a specified time period) or more, the process proceeds to step S108; otherwise, if the alignment is not met (less than N times), the process returns to step S106. The longitudinal reference 16b is displaced based on the rotation of the rotating unit 20, but is adjusted independently using the projection unit 18 to ensure perpendicularity. Therefore, there are cases where the position of the longitudinal reference 16b cannot be determined solely by the rotating unit 20; the standby process in step S107 ensures that the longitudinal reference 16b stably aligns with the target line 92c.

[0127] In step S108, the automatic setting mode ends and this information is notified to the laser marker 10. In step S204, the laser marker 10 confirms the end of the automatic setting mode and, according to specifications, sounds a buzzer to indicate the end. Afterwards, the user can fine-tune the position of the longitudinal reference 16b as needed by operating the knob 32. It should be noted that, alternatively, in step S201, the laser marker 10 may start a timer; if no transmission signal is received from the receiver 14 in steps S102, S104, S105, or S108 within a specified time, an error is considered, and necessary processing such as forcibly ending the automatic setting mode is performed.

[0128] In the first stage of the automatic setting mode, during the wide-angle rotation phase, the projector 18 rotates relatively quickly due to the stable characteristics of the DC motor 42. However, in the second stage, during the small-angle rotation phase, high-precision rotation at minute angles is required. The positioning accuracy of the projector 18, which is necessary based on the maximum application distance between the laser pointer 10 and the receiver 14, and the characteristics of the laser optical system, is, for example, around 2 to 6 seconds. That is, in the small-angle rotation phase, angle positioning control of the projector 18 needs to be performed with an accuracy of around 2 to 6 seconds. Correspondingly, braking is performed using 1 to 2 pulses output from the rotary encoder 44a. Therefore, the aim is to immediately shut off the motor 42 upon startup to minimize overshoot.

[0129] A typical DC motor generates maximum torque and has a steep operating characteristic during startup. Therefore, in this embodiment, a damping resistor 98d of the electrical mechanism and a leaf spring 46 of the mechanical mechanism are provided as dampers for the speed suppression mechanism (see Figure 7). The damping resistor 98d effectively smooths the acceleration of the motor 42 during startup. The leaf spring 46 primarily suppresses overshoot generated during inertial rotation. Through these measures, the rotational accuracy of the motor 42 corresponding to the 1-2 pulses output by the rotary encoder 44a and the positioning accuracy of the longitudinal reference 16b at an angle of 2-6 seconds are obtained. It should be noted that the damping resistor 98d and the leaf spring 46 are configured to have almost no effect on the rotational speed of the motor 42 in the wide-angle rotational stage.

[0130] The above example is based on the setting of the longitudinal reference 16b in the automatic setting mode, but the horizontal reference 16a can also be automatically set when the light receiver 14 is placed vertically. The transmission signal sent from the light receiver 14 to the laser marker 10 may not be a specific indication signal, but a code or the like with pre-defined indication content. In the automatic setting mode, the light receiver computer 94b, the light projector computer 96c, and the rotation computer 98a work together as a motor control unit, but the processing division of each computer is not limited to the above example. For example, the light receiver computer 94b may not perform the position determination of the longitudinal reference 16b, the rotation stop of the motor 42, or the determination of the rotation angle, but may directly send the signals obtained from the right sensor 92a and the left sensor 92b to the laser marker 10 via the input interfaces 94c and 94d. However, based on the necessity of controlling the illumination of LEDs 90a to 90c, various determinations are expected to be performed in the light receiver computer 94b.

[0131] The wire feeder unit 12 of this embodiment has the following first to fourth features. The first feature is that...

[0132] A line-laying unit comprises a laser line marker and a light receiver.

[0133] The laser marking device has a projection part that projects a laser beam to project a longitudinal marking onto an object, and a rotating part that supports the projection part from below and allows the projection part to rotate horizontally.

[0134] The rotating part has:

[0135] Driven gear, which rotates integrally with the light-projecting part;

[0136] A drive gear that drives the driven gear;

[0137] The motor is driven by the motor control unit;

[0138] A speed reducer that reduces the rotational speed of the motor and transmits it to the drive gear; and

[0139] An encoder, which is mounted on the rotating shaft of the motor,

[0140] The light receiver has:

[0141] Two light-receiving elements, which are adjacent in the lateral direction and respectively detect the longitudinal marker; and

[0142] The transmitting unit sends a transmission signal based on the detection values ​​of the two light-receiving elements to the laser marker.

[0143] In the automatic setting mode where the motor control unit positions the longitudinal tracing line as the target line between the two light-receiving elements, the motor control unit...

[0144] As a first stage, the motor is used to rotate the light-projecting part, thereby moving the longitudinal marker line.

[0145] As a second stage, the control is to, after either of the two light-receiving elements initially detects the longitudinal tracing line, cause the motor to rotate forward or reverse in a manner that the encoder outputs a predetermined number of pulses based on the received transmission signal, until the longitudinal tracing line is positioned between the two light-receiving elements as the target tracing line.

[0146] That is, in the first stage of wide-angle rotation mode, the projection unit 18 is rotated by motor 42, thereby moving the longitudinal reference 16b. In the second stage of small-angle rotation mode, the control is such that after either the right sensor 92a or the left sensor 92b initially detects the longitudinal reference 16b, the motor 42 is rotated forward or backward by outputting a predetermined number of pulses from the rotary encoder 44a until the longitudinal reference 16b is positioned on the target line 92c. In this way, motor 42 can perform small-angle rotation with good accuracy based on the signal from the rotary encoder 44a in the second stage, and can rotate at a relatively high speed in the first stage. Therefore, only one motor 42 is needed, which enables the laser line marker 10 to be miniaturized and lightweight, reducing the number of parts, improving assemblability, and reducing costs.

[0147] The second feature is based on the wire feeder unit of the first feature.

[0148] The motor control unit reduces the predetermined number of pulses (within a range that is not zero) and reverses the rotation of the motor whenever the longitudinal datum line crosses the target datum line. With this control, the longitudinal reference 16b can be positioned easily and reliably, essentially based solely on pulse signals, without relying on analog control.

[0149] The third feature is based on the wire feeder unit of the first feature.

[0150] The light receiver transmits a forward rotation signal as the transmission signal when one of the two light-receiving elements detects the longitudinal reference line, and transmits a reverse rotation signal as the transmission signal when the other of the two light-receiving elements detects the longitudinal reference line.

[0151] The motor control unit causes the motor to rotate forward and reverse based on the forward rotation signal and the reverse rotation signal. In this way, when determining the position of the longitudinal reference line and the direction of motor rotation on the light receiver side, the processing burden on the laser marker side is reduced, and the communication direction can be limited to a one-way direction from the light receiver to the laser marker.

[0152] The fourth feature is based on the wire feeder unit of the third feature.

[0153] In the automatic setting mode, when either of the two light-receiving elements initially detects the longitudinal marker, the light receiver sends a temporary stop signal as a transmission signal before sending the forward or reverse signal. Based on this temporary stop signal, the motor control unit temporarily stops the motor. This temporary stop enables stable small-angle movements in the second stage.

[0154] This invention is not limited to the above-described embodiments, and can of course be freely modified without departing from the spirit of this invention.

[0155] Explanation of reference numerals in the attached figures

[0156] 10 Laser Markers

[0157] 12 wire feeder units

[0158] 14. Light receiver

[0159] 16 Markings

[0160] 16b Longitudinal reference (longitudinal reference line)

[0161] 18 Light Projection Department

[0162] 20 Rotating part

[0163] 24. Shell

[0164] 24a Disc section

[0165] 24b Drum section

[0166] 28 Drive Mechanism Department

[0167] 32 knobs

[0168] 32a Knob Shaft

[0169] 32b knob worm gear

[0170] 34 Control board

[0171] 36 Driven gear

[0172] 42 motors

[0173] 42b motor shaft

[0174] 42ba front end

[0175] 42c motor worm gear

[0176] 44 Sensor Box

[0177] 44a Rotary Encoder

[0178] 46. ​​Leaf spring (elastic body)

[0179] 48 Resin Sheets

[0180] 50 Gear Reducer

[0181] 54 First drive wheel

[0182] 56 drive gears

[0183] 58 Planetary Gear Mechanism

[0184] 60 Second drive wheel

[0185] 64 Sun Gear

[0186] 66 Gear Ring

[0187] 68 small gears

[0188] 70 racks

[0189] 72 First Component

[0190] 74 Second component

[0191] 76 Springs

[0192] 78 First Gear

[0193] 80 Second Gear

[0194] 82 Spring

[0195] 86 Light-receiving window

[0196] 92a Right Sensor

[0197] 92b Left Sensor

[0198] 92c Marking Target Line

[0199] 94b Photodetector Computer

[0200] 94e Sending Module

[0201] 96c Radiant Computer

[0202] 96D receiver module

[0203] 98a Rotating Part Computer

[0204] 98d damping resistor.

Claims

1. A laser marking device, comprising a projection section for projecting a laser-formed marking onto an object and a rotating section for supporting the projection section and causing the projection section to rotate horizontally, wherein the laser marking device is characterized in that the rotating section comprises: a motor; Driven gear, which rotates integrally with the projector; drive gear, which drives the driven gear; knob, which is manually operated and rotated; planetary gear mechanism, which includes a sun gear, a ring gear, a carrier, and multiple pinions; A first drive wheel is located on the same axis as the sun gear and is arranged throughout the 360 ​​degrees and rotates integrally with the sun gear; a second drive wheel with external teeth is arranged throughout the 360 ​​degrees on the outer circumference of the gear ring; a motor worm gear is arranged on the rotation axis of the motor; and a knob worm gear is arranged on the rotation axis of the knob, wherein the first drive wheel meshes with the motor worm gear, and the second drive wheel meshes with the knob worm gear.

2. The laser marking device according to claim 1, characterized in that, The laser marking device has a backlash suppression mechanism to suppress the backlash between the driving gear and the driven gear.

3. The laser marking device according to claim 1, characterized in that, An encoder is provided on the rotating shaft of the motor, and the signal from the encoder is supplied to the control unit of the motor.

Images