JP2000015465A - Lense unit and device for laser marking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lense unit which need not adjust an angle of optical axis of LED pointer every time replacement with a fθ lens of different focus position is executed, which has less fear of touching the fθ lense, and which is easy in changing size and shape of the fθ lense, and to provide as well a device for laser marking equipped with such unit. SOLUTION: A fθ lens 11 is held in a lens holder 12 mounted attachably and detachably on a housing of a device for laser marking, and at the same time, on this lens holder 12, LED pointers 14, 14 are beforehand mounted through a holder plate 13 so that the position of a focus of the fθ lens 11 may pass its optical axis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens unit for holding a lens for converging a laser beam and a directional luminous body composed of an LED, and a laser marking device provided with this lens unit.

[0002]

2. Description of the Related Art A laser marking apparatus that irradiates the surface of various articles with a laser beam to mark patterns such as characters and figures can form a pattern that does not disappear. Responsibility Act) has been receiving attention with the enforcement of the Act.

[0003] In such a laser marking device, a laser marking device using carbon dioxide gas (CO ₂ gas) as an exciting medium is particularly composed of a laser control unit, a laser oscillator, a scanning unit and the like.

[0004] The laser control section comprises a microcomputer and a power supply. The microcomputer is
A print signal for marking a pattern such as a character and a figure is provided to the laser oscillator, and a scan signal for operating the scanning unit based on the pattern is provided to the scanning unit. On the other hand, the power supply has a function as a constant voltage power supply and applies a predetermined voltage to the laser oscillator.

The print signal is turned on / off by a HI / LOW signal. One pulse of the print signal corresponds to one pulse of the laser beam to be oscillated, and the laser signal is generated according to the pulse width at the HI. It is a PWM signal whose intensity can be adjusted. Since the frequency is generally fixed, the laser intensity per unit time is determined according to the duty ratio of the print signal, and the marking density is determined according to the scanning speed (also referred to as the scanning speed) in the scanning unit. Is also determined.

[0006] The laser oscillator is filled with carbon dioxide gas and has a built-in electrode. Laser oscillator
The carbon dioxide in the laser oscillator is excited based on the pulse width of the print signal provided from the laser control unit, and the laser is oscillated.

The scanning section includes a scanner, an fθ lens, and the like in a box-shaped housing provided adjacent to the laser oscillator, and is provided in the scanner based on a scanning signal given from the laser control section. By driving the galvano motor, the total reflection mirror provided on the output shaft is rotated. Thereby, the laser beam oscillated from the laser oscillator is deflected and scanned, and various patterns are marked on the surface of the article to be marked.

The fθ lens is a lens that converges the deflected laser beam, and is provided so that the deflected laser beam is incident on the central portion as parallel light in a state where the scanner is at the neutral position. For this reason,
The laser density is highest at the focal position of the fθ lens, and the scanner is scanned so that the pattern is marked in an area having the focal position substantially at the center.

In such a laser marking apparatus, each time the shape or size of an article placed on the transport path is changed, the center of the marking target area of the article coincides with the focal position so that Alternatively, the user adjusts the arrangement position of the laser marking device.

From this point, in order to show the focus position to the user, a directional illuminant provided on the laser marking device so that its optical axis passes through the focus position is provided separately from the laser marking device. The distance measuring means used was used in combination. By these, the transfer position or the arrangement position of the laser marking device is moved so that the irradiation position of the directional illuminant is located at the center of the marking target region, and the coincidence of the irradiation position and the center of the marking target region is maintained. The distance between the fθ lens and the irradiation position is measured by a distance measuring unit, and the position of the laser path or the laser path is moved until the distance matches the focal length of the fθ lens. I was doing specific.

[0011] As the directional luminous body, LED, L
It is common to use a so-called LED pointer that is combined with a lens that collects the light emitted from the ED.

When the fθ lens is damaged, when the transport path or the position of the laser marking device is restricted, the focal length cannot be secured, and when an fθ lens having a different material or a different optical property is used. For example, there is a case where the fθ lens that is attached in advance is replaced.

In such a case, first, the previously attached fθ lens is removed from the lens holder integrally provided in the housing, and a newly attached fθ lens is attached.
Assemble the θ lens in the reverse order. At this time, when the focal position is different between the fθ lens that is attached in advance and the fθ lens that is newly attached, the optical axis angle of the directional light emitter is adjusted.

[0014]

However, in the conventional laser marking apparatus as described above, every time the lens is replaced with an fθ lens having a different focal position, it is not only necessary to adjust the optical axis angle of the LED pointer but also to adjust the fθ angle. There is a problem that the operator touches the fθ lens and gets dirty because the lens itself is handled.

Further, the lens holder for holding the fθ lens is provided integrally with the housing, and it has been difficult to change the size and shape of the fθ lens.

The present invention has been made in view of the above circumstances, and has a lens holder detachably provided in the case to hold an fθ lens, and also preliminarily sets the focal position of the fθ lens in the lens holder. By attaching the directional luminous body so that the optical axis passes, it is not necessary to adjust the optical axis angle of the directional luminous body every time the lens is replaced with an fθ lens with a different focal position, and there is no fear of touching the fθ lens. It is an object of the present invention to provide an fθ lens unit that can easily change the size and shape of the fθ lens and a laser marking device including the unit.

[0017]

According to a first aspect of the present invention, there is provided a lens unit including a lens for converging a laser beam, holding means for holding the lens, and one or a plurality of light-emitting members provided on the holding means. Wherein the holding means is detachably attached to a laser marking device.

A lens unit according to a second invention is characterized in that the optical axis of the illuminant in the lens unit of the first invention is provided so as to pass through a focal position of the lens.

A lens unit according to a third aspect of the present invention is the lens unit according to the first or second aspect, wherein the plurality of light emitters are rotatably provided on the holding means.

A laser marking device according to a fourth aspect of the present invention
A lens unit according to any one of the first to third inventions is provided.

According to the lens units according to the first to third aspects of the present invention, one or more light-emitting members such as LED pointers are provided on a lens holder as a holding means for holding a lens such as an fθ lens, and the lens holder is laser-marked. When the fθ lens is replaced with a different fθ lens, the LED pointer is replaced together with the fθ lens. Therefore, for example, the optical axis of the LED pointer passes through the fθ lens focal position. The optical axis need not be adjusted each time the fθ lens is replaced. Further, since the entire lens holder is replaced, there is no need to touch the fθ lens, and it is easy to change the size and shape of the fθ lens.

According to the laser marking device of the fourth aspect, since the above-described lens unit is provided in the laser marking device, the above-described effects can be realized as a laser marking device.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. FIG. 1 is a perspective view showing a configuration of a lens unit 1 according to the present invention, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is a sectional view taken along line AA of FIG.

The lens unit 1 includes an fθ lens 11, a lens holder 12, a holder plate 13, and two LEs.
D pointers 14, 14, etc.

The fθ lens 11 is a circular germanium lens. The lens holder 12 includes a lens base 121, a lens holder 122, and an O-ring 123.
And so on.

The lens base 121 is a cylindrical member made of black alumite, and has a fixed flange at one end thereof. The fixed flange has four holes 121a, 121a,. I have. At the other end of the lens base 121, a thin portion from the inner diameter side is formed over an appropriate length,
The fθ lens 11 is fitted into the thin portion via the O-ring 123. Then, the small-diameter-side end of an annular lens holder 122 made of black alumite having a stepped portion on the outer periphery is brought into contact with the fθ lens 11 so as to abut the lens base 12.
The fθ lens 11 is held in the lens holder 12 by being fitted inside the thin portion 1.

The holder plate 13 is a plate member made of black anodized and having a substantially square shape.
21 and a circular cutout having the same size as the outer diameter of the lens retainer 122. On one side of the missing portion, a thin portion is formed over the entire circumference, and the lens holder 12 is fitted into the thin portion from the thin portion side, and the fixing flange of the lens mount 121 is embedded in the thin portion. It has become. Thereby, the lens holder 12 has its four holes 121a, 1
, Mounting screws 124, 124,.
Holder plate 1 corresponding to holes 121a, 121a,.
Are screwed into screw holes 136, 136,... Provided respectively at positions 3 so as to be mounted on the other side of the holder plate 13 in such a manner that the portion on the lens holder 122 side projects.

At four corners of the holder plate 13, mounting holes 135, 135 and 135 for the laser marking device are provided.
Are formed in the vicinity of two opposing corners of the holder plate 13, and holes 132, 132 penetrating in the thickness direction are respectively formed. These holes 132, 132 are formed on the same side as the lens holder 12. The positioning pins 15, 15 projecting from each other are fitted respectively.

Further, on the end face on the far side of the holder plate 13, rectangular protrusions each having a width of about one third of one side of the holder plate 13 are integrally formed, and the center of each protrusion is formed. Are provided with transmission holes 133 and 133 for transmitting the irradiation light from the LED pointers 14 and 14, respectively, and three screw holes 13 are provided around each of the transmission holes 133.
4, 134, 134 are provided.

On the side from which the positioning pin 15 of each projection projects, a pointer base 16 made of black alumite and having a rectangular plate shape for rotatably holding the LED pointer 13 is provided. In the center of each pointer base 16, there is an LED
A holding hole 161 formed by a part of a spherical surface for rotatably holding the pointer 14 is formed. In addition, each holding hole 161
Threaded holes 134, 134,
134, three insertion holes 162,
162 and 162 are provided. A mounting screw 17 is inserted into each of the insertion holes 162, and the tip of each mounting screw 17 is
Each pointer base 16 is screwed into a screw hole 134 of the holder plate 13 so that
It is fixed to.

As shown in FIG. 3, the LED pointer 14
Pointer case 1 made of black anodized cylindrical member
41, one end of which has a substantially spherical shape corresponding to the holding hole 161 of the pointer base 16. From the other end of the pointer case 141, turn the light emitting side end toward the spherical portion of the pointer case 141
143 is fitted in the middle part, and the convex lens 1 that converges the irradiation light from the LED 143 inside the spherical part at the one end.
42 are provided. The LED pointer 14 has such a configuration, and can freely rotate in the holding hole 161 with its spherical portion as a fulcrum, and can change the optical axis of the irradiation light from the LED 143 to various angles. It has become.

The lens unit 1 according to the present invention is configured as described above. The lens holder 12 is formed in accordance with the fθ lens 11 having a different shape or size, and the holder plate 13 is removed in accordance with the lens holder 12. By adjusting the parts, lens units 1 corresponding to various fθ lenses 11 can be formed.

Further, by adjusting the rotational position of each LED pointer 14 so that its optical axis passes through the focal position of the fθ lens 11, there is no need to adjust the optical axis after attaching to the laser marking device. It is possible to use it.

FIG. 4 is a block diagram showing the configuration of the laser marking device according to the present invention. As shown in FIG. 4, the laser marking device according to the present invention includes an input / display device 2,
It is composed of a laser controller 3, a laser unit 4, and the like.

The input / display 2 is a touch panel type L
In addition to displaying information provided from the laser control unit 3 connected to the CD, a pattern such as characters and graphics, and a frequency and a duty ratio of a print signal corresponding to the pattern are mainly input. The input result is provided to the laser control unit 3. Note that a configuration including a numeric key and a function key may be employed.

The laser control unit 3 includes a microcomputer 31 and a power supply 32, and stores the result of the input by the input / display unit 2 in a memory (not shown) built in the microcomputer 31. In addition, the laser control unit 3 supplies a print signal based on the frequency and the duty ratio stored in the memory to the laser unit 4, and outputs a scan signal based on the pattern stored in the memory to the laser unit 4, which will be described later. This is given to the scanning unit 44. Power supply 32
Has a function as a constant voltage power supply, and the laser unit 4
Is applied with a predetermined voltage.

The print signal is switched ON / OFF of the laser beam according to the HI / LOW, and a pulse corresponding to one pulse of the laser beam in which one pulse is oscillated.
The WM signal is a WM signal, and the laser intensity is determined based on the duty ratio according to the frequency. The laser intensity also changes depending on the scanning speed based on the frequency.

The laser unit 4 includes an oscillation section 43 and a scanning section 44. The oscillating unit 43 includes a box-shaped laser oscillator 431 in its housing. The laser oscillator 431 has carbon dioxide (CO
₂ ) is filled and incorporates an electrode (not shown), and excites carbon dioxide in the laser oscillator 431 based on a print signal given from the microcomputer 31 to cause laser oscillation.

The scanning unit 44 is provided adjacent to the oscillation side of the oscillation unit 43, and includes a beam expander 441, a scanner 4
42, and the lens unit 1 and the like.

The beam expander 441 converts the laser beam oscillated from the laser oscillator 431 into parallel light expanded in the radial direction, and assists the convergence in the fθ lens 11. The scanner 442 holds two total reflection mirrors 443 and 443 (see FIGS. 6 and 7) at an angle of 45 ° with each other as described later.
The total reflection mirrors 443 are rotated by the galvanometer motors 444 and 444 (see FIGS. 6 and 7), thereby enabling scanning in two orthogonal directions. I have.

As will be described in detail later, the lens unit 1 is positioned and attached to the scanning section 44 by its positioning pins 15 and 15. With this positioning, with the scanner 442 in the neutral position,
The laser beam deflected from the scanner 442 is incident on the central portion of the fθ lens 11 as parallel light.

The scanning section 44 having the above-described configuration is adapted to output a galvano motor 44 provided in the scanner 442 based on a scanning signal given from the microcomputer 31.
4, 444, the galvano motor 4
Total reflection mirrors 4 provided on output shafts 44 and 444, respectively
By rotating 43 and 443, the laser beam emitted from the laser oscillator 431 is deflected and scanned. The laser beam that has been deflected and scanned is applied to the surface of the workpiece W to be marked via the fθ lens 11 for marking.

The laser marking device provided with the lens unit 1 according to the present invention is configured as described above.
Prior to the marking, the LED pointers 14 provided on the lens unit 1
So that the center of the marked area of the workpiece W is located at the position where the light emitted from the two LED pointers 14 and 14 intersects, that is, at the focal position P of the fθ lens 11. Adjust the position of 4. Thereby, the alignment of the work W with respect to the laser beam transmitted through the fθ lens 11 and irradiated on the work W is completed.

At this time, the focal length is also determined at the same time. The focal length is determined by the surface of the work W and the fθ lens 11.
Back focal length (rear focal length), which is the distance between the last vertex of the lens, and the effective focal length, which is the distance between the surface of the work W and the principal point of the fθ lens 11. Good.

FIG. 5 is a perspective view showing a specific configuration of the laser marking device of FIG. In FIG. 5, the laser controller 3 and the laser unit 4 are connected via a connector 432. Further, the laser unit 4 is disposed above the transport path C in which the workpieces W, W,.

FIG. 6 is a side view showing the structure of the laser unit 4, showing a state in which upper housings 45 and 46 for covering the oscillating section 43 and the scanning section 44 have been removed, respectively. The description will be made on the upper side of the laser unit 4. FIG. 7 shows the upper housing 4.
FIG. 8 is a top view of the laser unit 4 in a state where the laser units 5 and 46 are removed, and FIG. 8 is a bottom view thereof.

The laser unit 4 has a substantially box shape that is long in the left-right direction in FIG. 6, and scans the oscillation unit 43 on one side (right side in FIG. 6) in the longitudinal direction and scans the oscillation unit 43 on the other side (left side in FIG. 6). The parts 44 are arranged respectively. Both the oscillation unit 43 and the scanning unit 44 are mounted on a metal bottom housing 47 having a rectangular plate shape.

The bottom housing 47 has a shape in which the inside of a flat peripheral edge having a predetermined width is recessed downward.
At a position between the oscillating unit 43 and the scanning unit 44, a first frame 48 having a substantially U-shape with its opening directed downward is vertically provided across the width direction of the bottom housing 47. A similar second frame 49 lower than the first frame 48 is provided at a longitudinal end of the bottom housing 47 on the oscillation section 43 side. On the width direction side surface of the bottom housing 47 of the first frame 48, two on each side are provided.
Are provided in the same manner, and two screw holes 491, 49 are provided on each side of the bottom frame 47 of the second frame 49 in the width direction.
1,... Are provided.

The upper housing 45 on the side of the oscillator 43
Are provided so as to inscribe the first and second frames 48 and 49, and are provided on the scanning unit 44 side and the bottom housing 4.
7 has a box shape covering four surfaces other than the lower side, and an upper portion of the side away from the scanning unit 44 is recessed in a box shape over a predetermined length, and a connector 432 is disposed in the recessed portion. You. A plurality of slit-shaped ventilators 451 for forced air cooling are provided on the side surface of the upper housing 45, and holes are provided at positions corresponding to the screw holes 481, 481,... And the screw holes 491, 491,. 452
452 are provided.

On the other hand, the upper housing 46 on the side of the scanning section 44 is inclined to the side away from the oscillating section 43 and substantially covers four surfaces other than the oscillating section 43 and the lower side covered by the bottom housing 47. A motor housing 461 having a box shape and a spherical shape is formed on an upper portion thereof. Further, an insertion portion 462 inserted into the oscillation portion 43 is provided at an end of the upper housing 46 on the oscillation portion 43 side.
Are provided in a strip shape.
81, 481,...
463,... Are provided respectively.

With the housing configuration as described above, the upper housing 46 on the scanning section 44 side is placed on the bottom housing 47, and the upper housing 45 on the oscillation section 43 side is placed on the bottom housing 47. A hole 45 provided in the upper housing 45 on the 43 side
Insert mounting screws (not shown) into 2,452,.
Screw holes 481 and 481 provided in the first frame 48
, The upper housing 46 on the scanning section 44 side is fixed, and the left end side of the upper housing 45 on the oscillation section 43 side is fixed. Similarly, by screwing the mounting screws into screw holes 491, 491,... Provided in the second frame 49, the right end side of the upper housing 45 on the oscillating portion 43 side is fixed. .

A partition (not shown) made of an elastic material such as a resin material or a foamed resin material is provided inside the first frame 48. The laser oscillator 4 attached above is brought into close contact with the side surface on the scanning section 44 side. As a result, the laser beam oscillated from this side is irradiated onto the scanning unit 44 without leaking.

The irradiated laser beam is changed into parallel light expanded in the radial direction by the beam expander 441 as described above, and is irradiated on the scanner 442. The scanner 442 includes two circular total reflection mirrors 443 and 443.
(Only one is shown) is provided at an appropriate distance in the horizontal direction perpendicular to the optical axis of the laser beam from the beam expander 441. One total reflection mirror 443
Is tilted 45 ° toward the beam expander 441 and 45 ° toward the other total reflection mirror 443. Similarly, the other total reflection mirror 443 is moved toward the one total reflection mirror 443. The scanner 442 is tilted 45 ° and tilted 45 ° below the laser unit 4. In this state, the scanner 442 is in a neutral state.

Each total reflection mirror 443 is a galvano motor 4 having an output axis in a direction parallel to the optical axis of the laser beam from the beam expander 441 and an output axis in the vertical direction.
Each of them is fixedly mounted at 44 so as to be rotated. As a result, the laser beam from the beam expander 441 reflects off the other total reflection mirror 443 via the one total reflection mirror 443, and is irradiated and scanned below the laser unit 4. I have.

FIG. 9 is a perspective view showing a state where the lens unit 1 is attached to the laser unit 4. As shown in FIG. 9, a concave portion 470 corresponding to the shape of the holder base 13 of the lens unit 1 is integrally formed from the lower surface side of the bottom housing 47 on the scanning section 44 side. The recess 470 is
The LED pointers 14 and 14 are positioned at positions corresponding to the LED pointers 14 and 14 and the position corresponding to the lens holder 12, respectively.
And holes 471, 471, 472 of such a size that they do not interfere with the lens holder 12, respectively.

The positions of the recesses 470 corresponding to the four mounting holes 135, 135,.
Are respectively provided with screw holes 473, 473,..., Respectively, and mounting screws 18, 18,... Are screwed from outside of the holder plate 13 to fix the lens unit 1 in the concave portion 470. Since the depth of the concave portion 470 is equal to the thickness of the holder plate 13, the lower surface of the bottom housing 47 is substantially flat when the lens unit 1 is attached as described above.

Further, positioning holes 474 and 474 are precisely arranged at positions of the concave portions 470 corresponding to the two positioning pins 15 and 15 of the lens unit 1, respectively. Therefore, the center position of the fθ lens 11 coincides with the irradiation position of the laser beam in the neutral state of the scanner 442 by the positioning pins 15 and 15 fitted into the positioning holes 474 and 474.

[0058]

As described in detail above, in the lens unit according to the present invention and the laser marking apparatus provided with this unit, a lens holder as a holding means for holding a lens such as an fθ lens emits light such as an LED pointer. Since one or more bodies are provided and the lens holder is detachably attached to the laser marking device, when exchanging the fθ lens with a different focal position, in order to exchange the LED pointer together with the fθ lens, for example, an LED is used.
By previously adjusting the optical axis of the pointer so as to pass through the focal position of the fθ lens, it is not necessary to adjust the optical axis each time the fθ lens is replaced. Further, since the entire lens holder is replaced, there is no need to touch the fθ lens, and it is easy to change the size and shape of the fθ lens.

Further, since the above-described lens unit is provided in the laser marking device, the present invention has excellent effects such that the above-mentioned effects can be realized as a laser marking device.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a lens unit according to the present invention.

FIG. 2 is an exploded perspective view of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 1;

FIG. 4 is a block diagram showing a configuration of a laser marking device according to the present invention.

FIG. 5 is a perspective view showing a specific configuration of the laser marking device of FIG. 4;

FIG. 6 is a side view illustrating a configuration of a laser unit.

FIG. 7 is a top view of the laser unit with the upper housing removed.

FIG. 8 is a bottom view of the laser unit with the upper housing removed.

FIG. 9 is a perspective view showing a state where the lens unit is attached to the laser unit.

[Explanation of symbols]

 Reference Signs List 1 lens unit 4 laser unit 11 fθ lens 12 lens holder 13 holder plate 14 LED pointer (directional light emitter)

Claims (4)

[Claims] 1. A laser marking apparatus comprising: a lens for converging a laser beam; holding means for holding the lens; and one or a plurality of light emitters provided on the holding means, wherein the holding means is detachable from a laser marking device. A lens unit characterized by being attached to a lens. 2. The lens unit according to claim 1, wherein the luminous body is provided so that an optical axis thereof passes through a focal position of the lens. 3. The lens unit according to claim 1, wherein the plurality of light emitters are rotatably provided on the holding unit. 4. A laser marking device comprising the lens unit according to claim 1.