JP2008175673A - Laser marking machine - Google Patents

Abstract

Disclosed is a laser marking device capable of preventing line light projection position shift caused by static electricity without causing a shift in a stationary position of the swing body by discharging an electric field around the swing body. obtain.
A light source unit that emits laser line light, an oscillating body that holds the light source unit, an oscillating support that supports the oscillating body so as to oscillate with respect to a base, and a base. A plastic body case 10 fixed to the base 1 and covering the internal mechanism, and an unequal electric field is formed between the rocking body 8 and the body case 10, and the potential difference generated between the rocking body 8 and the body case 10 is self-generated. Neutralizing means for removing by discharging. The neutralizing means is composed of the planar electrode 12 and the tip electrode 11 facing each other, and the tip electrode 11 is preferably made of conductive fibers.
[Selection] Figure 1

Description

  The present invention relates to a laser marking device in which a rocking body to which a light source unit is attached is swingably supported by a rocking body support member such as a gimbal mechanism, and line light is projected from the light source unit. It is an object of the present invention to provide a laser marking device capable of preventing the deviation of the projection position of line light due to the influence of static electricity by removing static electricity between the oscillator and the case.

  In a construction site or the like, a laser inking device that projects laser line light for inking on an irradiation target surface such as a wall, ceiling, or floor is used. A semiconductor laser is generally used as the laser light source of the laser marking device. Since the laser light emitted from the semiconductor laser is diffused light, it is converted into a substantially parallel light beam by a collimating lens, which is diffused only in one direction by passing through a cylindrical rod lens, etc. If the light is projected onto a surface to be irradiated such as a ceiling or a floor, a vertical line or a horizontal line by a laser beam can be drawn. Therefore, a light source unit is constituted by a semiconductor laser, a collimating lens, a rod lens, and a holder that integrally holds these optical components, and the laser is assembled by assembling the light source unit to a rocking body suspended by a rocking support. A summoning device can be constructed. Even if the laser marking device is installed at an angle, the above-mentioned oscillating body suspended by the oscillating support body can always maintain a predetermined posture, and the light source unit assembled to the oscillating body allows the vertical direction. Alternatively, the horizontal line light is correctly projected onto the irradiation target surface. A vertical pointer that can project a light spot on the ceiling surface directly above the installation reference point or the floor surface directly below it is also a kind of laser marking device. Some laser marking devices that project line light as described above have a vertical pointer function.

  A gimbal mechanism is generally used as the swing support. The gimbal mechanism uses a precision component such as a ball bearing as a bearing, and a shaft is rotatably supported by the pair of bearings, and the swinging body is suspended by the shaft so as to be swingable. More specifically, a pair of first horizontal shafts are supported on a common straight line via a pair of bearings on a fixed frame or a support column fixed to the base body, and the swing frame is supported by the first horizontal shaft. The swinging frame supports the second horizontal shaft via a bearing in a direction orthogonal to the horizontal axis, and the swinging body is swingably supported by the second horizontal shaft.

Since the rocking body is required to hang down in the direction of gravity and stop in a predetermined posture, it is desirable that the rocking support including a gimbal mechanism has as little frictional resistance as possible. Since the frictional resistance of the oscillating support is small, the variation in the stationary position of the oscillating body becomes very small. This state is called “high sensitivity” of the oscillator. Since the oscillating body supported by the oscillating support composed of a gimbal mechanism using a ball bearing has high sensitivity, variation in the stationary position of the oscillating body is extremely small, and the irradiation position accuracy of the line light is high.
However, the high sensitivity of the oscillating body means that the oscillating body also oscillates even when a minute external force is applied to the oscillating body. Further, when the laser marking device is installed, it takes a long time for the oscillating body to shake for a long time and settle down to a predetermined posture. Therefore, a laser marking device in which a rocking body is rockably supported by a rocking support member incorporates a braking device or a braking mechanism as described in the following patent document.

  The braking device in the laser marking device described in Patent Document 1 has a nonmagnetic metal plate attached integrally with a rocking body, and an upper plate body and a lower plate with a predetermined gap above and below the nonmagnetic metal plate, respectively. The body is fixed to the frame and the base, and magnets are attached to the upper plate and the lower plate, respectively. Magnetic fields are formed on the upper plate and the lower plate. When the non-magnetic metal plate crosses the magnetic field as the oscillating body swings, an eddy current flows through the non-magnetic metal plate, and this eddy current acts as a braking force against the swing of the oscillating body. To settle down in a predetermined position.

  The braking device in the laser marking device described in Patent Document 2 has a brake plate having a curved surface along the oscillating imaginary line in the vicinity of the lower portion of the oscillating body, and one piece facing the surface of the brake plate. Alternatively, a plurality of electromagnets are arranged, and when desired, for example, when installing a laser marking device, the electromagnet is turned on to generate an attraction force between the brake pieces, and the attraction force causes the oscillator to swing. Is to be stopped.

JP-A-10-325723 Japanese Patent Laid-Open No. 11-257862

In addition to the inventions described in Patent Document 1 and Patent Document 2, various techniques for preventing wobbling of the rocking body due to high sensitivity of the rocking body have been proposed.
However, attention has not yet been paid to the occurrence of a stationary position shift of the oscillator due to the influence of static electricity due to the high sensitivity of the oscillator.

  The majority of laser marking devices are one-piece molded parts made of plastic. Plastic materials are also charged by friction with air. There is no exception in the case of a plastic laser marking device. Since the oscillator of the laser marking device has high sensitivity, when the plastic main body case is charged, the oscillator is attracted to the main body case by electrostatic attraction, and the stationary position of the oscillator is moved from the predetermined position. Shift. In particular, in winter when the humidity is low, the plastic body case is easily charged, and the electrostatic attraction force is large. If the main body case is charged, an error also occurs in the assembly and adjustment process of the laser marking device, and an error also occurs during use. Even if the main body case is not charged, when the charged human body approaches the inking device, the rocking body is attracted by the electric field emitted from the human body, and the line light is projected due to the stationary position shift of the rocking body. A position error is generated.

  Although it may be possible to prevent charging by making the body case conductive, such as by forming the body case with conductive plastic, there is a problem when using a laser marking device, that is, a charged human body approaches. The problem of errors caused by an external electric field cannot be solved.

  The present invention has been made in order to solve the above-described problems of the prior art, and a rocking body to which a light source unit is attached is supported by a rocking body supporting member such as a gimbal mechanism so as to be swingable. In a laser marking device that projects light, by discharging the electric field around the rocking body, there is no shift in the stationary position of the rocking body, and the light projection position shift of the line light caused by static electricity is prevented. An object of the present invention is to provide a laser marking device that can be prevented.

  The present invention includes a light source unit that emits laser line light, an oscillating body that holds the light source unit, an oscillating support that oscillates the oscillating body with respect to the base, and a base that is fixed to the base. A plastic main body case that covers the mechanism; and a static elimination unit that forms an unequal electric field between the oscillator and the main body case and removes a potential difference generated between the oscillator and the main body case by self-discharge. This is the main feature.

If there is a potential difference between the main body case and the rocking body due to factors such as the plastic main body case being charged with static electricity, this potential difference is removed by the self-discharge of the static elimination means, and electrostatic attraction acts on the rocking body. Power is lost. As a result, the oscillating body is stationary in a predetermined posture, and the line light is projected with high accuracy without wobbling with respect to the target position.
Even when an electrostatically charged human body or the like approaches, the potential difference generated between the main body case and the rocking body is removed by self-discharge of the static eliminating means, and the rocking body is stopped in a predetermined posture.

Embodiments of a laser marking device according to the present invention will be described below with reference to the drawings.
1 and 2 schematically show an embodiment of a laser marking device according to the present invention. 1 and 2, reference numeral 1 indicates a base of a laser marking device. The base 1 has a tripod (not shown) in the lower part, or can be mounted with a tripod, and can be installed on a floor or the like in a horizontal posture by the tripod. An appropriate number of support columns 2 are erected on the base 1, and the support 2 also constitutes a part of the base 1.

  A swing support 3 is attached to the upper end of each support 2 via a suitable mediating member. The rocking support 3 is composed of a ball bearing. The ball bearing has an outer ring 4, an inner ring 5, and a plurality of spheres 6 interposed between the outer ring 4 and the inner ring 5. When the sphere 6 rolls, the outer ring 4 and the inner ring 5 have a low frictional resistance. And can be rotated relatively smoothly. The outer ring 4 is fixed to the column 2 via the appropriate mediating member. In the illustrated example, two swing support bodies 3 are paired, and each swing support body 3 is supported by two support columns 2. The sphere 6 is made of, for example, a steel ball.

  The pair of swing support bodies 3 are arranged to face each other so that their central axes coincide with each other, and the shaft 7 is press-fitted through the inner ring 5 of each swing support body 2. The inner ring 5 is integrally supported so as to be rotatable. The shaft 7 penetrates the rocking body 8 and is integrally coupled to the rocking body 8. The oscillating body 8 is supported in a swingable manner like a pendulum between the two pairs of support columns 2 around the horizontal axis 7.

  A light source unit 9 is attached to the upper end portion of the swinging body 8 protruding upward from the pair of swinging support bodies 3. The light source unit 9 includes a semiconductor laser (laser diode) as a light source, a collimating lens that makes diffuse laser light emitted from the semiconductor laser a parallel light beam, and a cylindrical rod lens that diffuses the parallel light beam only in one direction. And a holder for holding these optical components together. The light source unit 9 is a light source unit for projecting vertical line light. When the rod lens is directed in the horizontal direction, the laser beam is diffused in the vertical direction. The holder constituting the light source unit 9 is attached to the upper end of the rocking body 8 so as to be inclined obliquely upward. Instead of the light source unit 9 for projecting vertical line light, or together with the light source unit 9, a light source unit for projecting horizontal line light can be attached to the oscillator 8. Similarly to the light source unit 9, the light source unit for projecting horizontal line light includes a semiconductor laser, a collimating lens, a rod lens, and a holder. When the rod lens is directed in the vertical direction, the laser The difference is that the light beam is diffused only in the horizontal direction.

  In the illustrated example, the swing support body 3 is configured to support the swing body 8 so as to be swingable in only one direction. However, the swing body 8 swings about two horizontal axes orthogonal to each other. A gimbal mechanism that can be supported may be used. When a gimbal mechanism is used, the intermediate rocking body is supported by the base 1 or a support column 2 forming a part of the base so that the intermediate rocking body can swing freely, and the intermediate rocking body is orthogonal to the first axis. A swinging body is swingably supported in a pendulum shape via a second axis in the horizontal direction. If the gimbal mechanism is used, there is an advantage that the posture of the rocking body 8 can be corrected to a predetermined posture even when the base 1 is inclined in any direction. The gimbal mechanism is sometimes referred to as a gyro mechanism.

  A main body case 10 is fixed on the base 1. The body case 10 is a part integrally formed of plastic, and is fixed on the outer peripheral edge of the base 1 so as to cover the internal mechanism described so far. As described above, the plastic main body case 10 is a member that is easily charged by static electricity. When the main body case 10 is charged, the oscillating body 8 cannot be stopped at a predetermined position because the oscillating body 8 is attracted by the electrostatic attraction force as in the previous operation. Therefore, in the illustrated embodiment, there is provided a static elimination means for removing a potential difference generated between the oscillating body 8 and the main body case 10 by self-discharge by forming an unequal electric field between the oscillating body and the main body case. Yes. More specifically, the charge eliminating means includes a pointed electrode 11 and a planar electrode 12 provided opposite to the main body case 10 and the oscillator 8. In the illustrated embodiment, the tip electrode 11 is attached to the lower end of the rocking body 8 so as to protrude on both sides of the rocking direction, and the planar electrode 12 is disposed on the inner wall surface of the body case 10 facing the rocking body 8 therebetween. Yes. “Uneven electric field” means a state in which the electric field between the electrodes facing each other is not uniform. In the illustrated embodiment, the electric field between the flat electrode 12 and the pointed electrode 11 is concentrated on the pointed electrode 11. It is formed. The planar electrode 12 may be formed by fixing an electrode plate to the inner surface of the main body case 10 or may be formed by applying conductive plating to the inner surface of the main body case 10.

  The pointed electrode 11 may be an electrode having a needle-like tip, but may be composed of, for example, a conductive fiber. In the Example of this invention, the conductive fiber "Celmec" (brand name) developed by Kuraray Co., Ltd. was used. This conductive fiber has innumerable fluff-like discharge tips, and the discharge between the conductive electrode and the flat electrode 12 can be distributed to the respective discharge tips. The pointed electrode 11 is preferably connected to a ground terminal provided at an appropriate position of the laser marking device and appropriately grounded via the ground terminal. Since the conductive fibers include cloth-like, tape-like, and string-like ones, those having an appropriate form are selected and used. The conductive fiber “Celmec” is a special conductive fiber different from a metal fiber, and has a property of discharging an unequal electric field by corona discharge. For example, assuming that a charged material with a high voltage such as +50 kv and an uncharged material such as +1 kv are adjacent to each other with the conductive fiber as a boundary, the conductive fiber has a potential difference between the charged material and the uncharged material. Self-discharge occurs by corona discharge, eliminating the potential difference between the two.

  In the illustrated embodiment, the static elimination means is arranged at the maximum displacement generating portion in the direction in which the stationary position error of the oscillator 8 is likely to occur. That is, in FIG. 1, the rocking body 8 is supported so as to be able to rock freely in a direction parallel to the paper surface about the shaft 7, and this rocking plane direction is a direction in which a stationary position error of the rocking body 8 is likely to occur. is there. When the swinging body 8 swings, the position where the corners on both sides of the swinging body 8 abut against the inner wall surface of the main body case 10 is the maximum displacement generating portion of the swinging body 8, and the tip electrode 11 and the planar electrode 12 are formed at this position. Static elimination means is arranged. Since the oscillating body 8 reciprocally oscillates, the maximum displacement generating portion is on both sides of the oscillating direction, and the charge eliminating means is disposed on both sides of the oscillating direction. In FIG. 1, reference numerals 11 </ b> A and 11 </ b> B indicate a state in which the tip electrode 11 moves relative to the main body case 10 as the swing body 8 swings.

  According to the laser marking device according to the illustrated embodiment described above, the plastic body case 10 is provided by disposing the charge eliminating means for removing the potential difference generated between the oscillator 8 and the body case 10 by self-discharge. Is charged and a potential difference is generated between the main body case 10 and the rocking body 8, the static elimination means removes the potential difference by self-discharge, and an electrostatic attraction force between the main body case 10 and the rocking body 8. Is solved. Therefore, there is no deviation of the stationary position of the rocking body 8 due to the electrostatic attractive force, and it is possible to avoid the deterioration of the line light irradiation position accuracy caused by the electrostatic attractive force.

Even when a charged human body approaches, the neutralization means removes the potential difference generated between the oscillator 8 and the oscillator 8 by self-discharge, so that it is possible to avoid deterioration of the line light irradiation position accuracy caused by electrostatic attraction force. Can do.
In particular, static electricity is likely to be generated in the winter when the air is dry, and the accuracy error of the laser marking device is likely to occur. However, according to the laser marking device of the present invention, line light irradiation caused by static electricity is also caused in the winter. It is possible to project laser line light with high positional accuracy while avoiding deterioration of positional accuracy.

It is a side view which shows the Example of the laser marking device which concerns on this invention typically. It is a front view which cuts off a part of said Example and shows it model-wise.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Support | pillar 3 Oscillation support body 4 Outer ring 5 Inner ring 6 Sphere 7 Axis 8 Oscillation body 9 Light source unit 10 Main body case 11 Pointed electrode 12 Planar electrode

Claims (7)

A light source unit that emits laser line light;
A rocking body holding a light source unit;
A swing support that swingably supports the swing body with respect to the base;
A plastic body case fixed to the base and covering the internal mechanism;
A laser marking device comprising: an unequal electric field between the oscillating body and the main body case, and neutralizing means for removing a potential difference generated between the oscillating body and the main body case by self-discharge.   2. The laser marking device according to claim 1, wherein the static eliminating means comprises a planar electrode and a tip electrode facing each other.   3. The laser marking device according to claim 2, wherein the tip electrode is made of a conductive fiber.   2. The laser marking device according to claim 1, wherein the static eliminating means is arranged at a maximum displacement generating portion in a direction in which a stationary position error of the oscillator is likely to occur.   3. The laser marking device according to claim 2, wherein the planar electrode is disposed on the inner wall surface of the main body case.   2. The laser marking device according to claim 1, wherein the rocking support is formed of a ball bearing and supports the rocking body so as to be rockable about an axis in one direction.   2. The laser marking device according to claim 1, wherein the swinging support member comprises a gimbal mechanism that supports the swinging member so as to be swingable about an axis in one direction and an axis in a direction perpendicular thereto.

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