JPH10282452A - Laser pointer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a compact and low-priced laser pointer capable of realizing wide scanning and plotting a complicated geometric pattern by rocking a magnet with a mirror surface to reflect a laser beam and introducing the laser beam to the surface of the rocking magnet. SOLUTION: The surface 2 of the magnet 3 is worked in a mirror surface in order to reflect the laser beam 12. When external force is exerted on the magnetization of the magnet 3 by alternating magnetic field and the frequency thereof coincides with the natural oscillation of a mechanical system, resonance is caused and the magnet 3 worked to be the mirror surface is rocked at maximum amplitude by the slight alternating magnetic field generated from a chip coil 6a. The laser beam 12 projected from a laser beam generating means 11 is introduced to the surface 2 of the rocked magnet 3 and reflected by an optical path changing device 40 where a mirror for reflection is fixed, and the movement of the rocked magnet 3 is plotted on a projection surface at high speed. Therefore, an extremely wide straight line or curved line is plotted on the projection surface with the motion of the magnet 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser pointer for drawing a line or a curve by irradiating a laser beam on a vibrating or oscillating mirror and irradiating the reflected light on a projection surface. In particular, the magnet attached to the end of the elastic wire and mirror-finished to reflect the laser beam is swung by a plurality of magnetic field generating means to produce a wide range of lines, circles, ellipses, or various geometrical shapes. The present invention relates to a laser pointer capable of drawing a scientific pattern or the like.

2. Description of the Related Art Conventionally, lasers for drawing lines, circles and ellipses
Examples of the pointer include those disclosed in, for example, JP-A-07-64018 or JP-A-07-64019. It consists of attaching a reflecting mirror to one end of a bimorph type piezoelectric element, vibrating it by applying an AC voltage to the piezoelectric element, introducing laser light to the vibrating mirror, and applying the reflected light to the projection surface. This is to draw. In detail, as shown in FIG.
The two bimorph type piezoelectric elements are arranged so that their vibration directions are orthogonal to each other, and the tip of each of them (piezoelectric element X24, piezoelectric element Y23) has a mirror-2 with a displacement enlarging mechanism.
1, 22 are fixed and face each other. And
Laser light emitted from a semiconductor laser 26 installed inside is reflected by the two mirrors and emitted from an opening (not shown).
When an AC voltage having a specific frequency fx is applied to the piezoelectric element X24, the mechanical system including the piezoelectric element X and the mirror 22 resonates at the natural frequency fx, and emits laser light X.
Scan in the axial direction. Similarly, when an AC voltage having a specific frequency fy is applied to the piezoelectric element Y23, the mechanical system including the piezoelectric element Y and the mirror 21 has a natural frequency fy.
Causes a resonance vibration, and the laser light is scanned in the Y-axis direction. At this time, it is possible to draw a straight line, a circle, an ellipse, and the like by the phase difference or the voltage difference between the electric signals fx and fy.

However, in the above-mentioned conventional example, a so-called bimorph type piezoelectric element in which a piezoelectric element is adhered to both sides of a metal plate is used as a shaft plate for vibrating the mirror. Basically, since the displacement of the piezoelectric element is used, even if an enlargement mechanism is adopted at the tip, the displacement of the mirror tip is at most about 400 μm, which is approximately 1.5 μm in terms of deflection angle. Despite the fact that the reflection angle is doubled due to the law of light reflection, only 3
In other words, the laser scanning width 3 m ahead is only about 120 mm, and it is impossible to scan the entire width of the projection surface 3 m away and point to the entire row or column. Also, when a high voltage is applied to force more resonance, the piezoelectric element is made of ceramic and has a different elastic limit from the metal substrate that forms the bimorph, so the piezoelectric element peels off or breaks from the metal substrate. There were drawbacks. In the conventional example, two piezoelectric bimorphs having a length of about 30 mm are used, and a mirror and a holding component are attached to each of them. The number of components is large, and the shape, processing accuracy, and mounting accuracy of the holding component are large. Due to the variation, the resonance frequency and the amplitude are different, and further control components and the like are required to adjust the variation,
It did not contribute to lower prices. The present invention has been made in order to solve the above-described problems, enables stable scanning with a small number of parts, enables a large deflection angle of 40 degrees or more without breaking, that is, enables a wide scan, It is another object of the present invention to provide a small and inexpensive laser pointer capable of drawing a complicated geometric pattern.

In order to achieve this object, a laser pointer according to the first aspect of the present invention causes a laser beam to be incident on one or more vibrating mirrors and vibrates. A laser pointer for drawing a line or a curve by irradiating light reflected by a mirror onto a projection surface, comprising a housing for fixing an elastic line and a rear end of the elastic line, and a front end of the elastic line. A fixing jig for fixing a mirror-finished magnet, a magnet fixed by the fixing jig and mirror-finished for reflecting a laser beam, and a singular for rocking the magnet Alternatively, a plurality of magnetic field generating means and a laser are provided on the surface of the rocked magnet.
And an optical path changing device for introducing the light, and the mirror-finished magnet at the distal end of the elastic wire receives an external force due to an alternating magnetic field generated by one or more magnetic field generating means from the outside, and oscillates. Can be done. Further, since the rocked magnet receives a restoring force proportional to the rocking amount from the elastic wire, it becomes a so-called resonance system. When a periodic magnetic field is applied from the magnetic field generating means, resonance occurs and the magnet is rocked largely. Laser
The light is introduced into the surface of the magnet that has been greatly swung through the optical path changing device, is reflected at a double angle by the reflection law, and is drawn on the projection surface. Therefore, it is possible to draw a straight line or a curve much larger than the conventional example. Further, in the laser pointer according to the second aspect, the elastic line is made of a shape memory alloy having a superelastic characteristic having a higher elastic limit. Shape memory alloys with superelastic properties have much higher elastic limits than ordinary metals, and can bend more by external forces. Therefore, by introducing and reflecting the laser light on the surface of the oscillating magnet, a straight line or a curve can be drawn at a larger angle, that is, a wider width. According to a third aspect of the present invention, in the laser pointer, the optical path changing device comprises an elastic line, a housing for fixing a rear end of the elastic line, and a magnet having a mirror-finished end portion of the elastic line. A fixing jig for fixing, a magnet fixed by the fixing jig and having a mirror-finished surface for reflecting laser light, and one or more magnetic fields for swinging the magnet from outside Generating means. Therefore, if an alternating magnetic field is also generated by the magnetic field generating means provided in the optical path conversion device, the magnet provided in the optical path conversion device also swings, so that the laser introduced on the surface of the magnet is also used. The light is reflected according to its swing angle; Therefore, the laser
Since light is reflected from the surface of a plurality of oscillating magnets with different frequencies, the projection surface has complex geometric patterns based on circles or ellipses depending on the difference in the frequency or the difference in the amplitude. Can be drawn. Claim 4
The laser pointer described in (1) uses a chip coil of several mm square having a core of ferrite or soft magnetic iron as its magnetic field generating means. Therefore, it is possible to provide a laser pointer that is much smaller and less expensive than the conventional one.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a laser according to this embodiment.
This shows the structure of the pointer, which largely includes a laser beam generating means 11, an optical path changing device 40, and a mirror oscillating section.
Divided into ten . In the mirror oscillating portion 10 , reference numeral 1 denotes an elastic wire used in the present invention. In this embodiment, a shape memory alloy made of NiTi exhibiting superelastic characteristics is employed in order to oscillate more greatly. Its length is about 10mm, wire diameter is about 3
00 μm. Reference numeral 3 denotes a magnet whose surface 2 is mirror-finished to reflect laser light, and has an outer diameter of 5 mm and a thickness of 1 mm. The material is aluminum, nickel and cobalt, which are common magnets.
It has a residual magnetic flux density of about 10,000 Gauss. Reference numeral 4 denotes a fixing jig for fixing the mirror-finished magnet 3 to the elastic wire 1.
Three small holes are drilled. And elastic wire 1
Are inserted, and the magnet 3 and the elastic wire 1 are firmly connected together with an adhesive. Numeral 5 is a magnetic field generating means for generating a magnetic field in the Y-axis direction.
And an alternating current generator 5b for applying an alternating current to the chip coil. Similarly, reference numeral 6 denotes a magnetic field generating means for generating a magnetic field in the X-axis direction. The magnetic field generating means comprises a chip coil 6a in which a ferrite of several mm square is coiled and an alternating current generator 6b for applying an alternating current to the chip coil. Thus, the shape and the magnitude of the inductance are the same as those in the Y-axis direction. Reference numeral 9 denotes a housing for fixing an elastic wire having a magnet 3 and a fixing jig 4 which are mirror-finished at the tip, and is divided into 9a and 9b.
And the length of the elastic wire can be adjusted by screwing 9a and 9b. Reference numeral 11 denotes a laser light generating means, and the laser light 12 emitted from the means is provided.
Is configured such that the optical path is bent by the optical path conversion device 40 and guided to the mirror-finished magnet surface 2. In general, it is known that a mechanical system in which a mass is fixed at the tip of such an elastic wire has a natural frequency related to the spring constant of the elastic wire and the inertia moment of the mechanical system. . Then, as shown in FIG. 2, the magnetization M of the magnet 3 receives an external force due to the alternating magnetic field H. When the frequency ω matches the natural frequency ω ₀ of the mechanical system, resonance occurs, and the chip coil 6a generates the resonance. With a slight alternating magnetic field H, the mirror-finished magnet 3 is swung at the maximum amplitude θmax. The laser light 12 emitted from the laser light generating means 11 is introduced into the surface 2 of the oscillating magnet 3 by an optical path changing device 40 to which a reflecting mirror (not shown) is fixed. The reflected and oscillated movement of the magnet 3 is drawn at high speed on a projection plane (not shown). Next, the operation of the laser pointer having the above configuration will be described. As shown in FIG. 3, when an alternating pulse current is applied to the chip coil 6a by the alternating current generator 6b, an alternating magnetic field H is formed around the chip coil 6. And the magnet 3 of magnetization M fixed to the tip of the elastic wire 1
As shown in FIGS. 4 (a) and 4 (b), M · M around the fixed point O fixed by the housing 9 by the alternating magnetic field H.
It receives torque of H · cos θ. This is because the magnetic charge + m shown in (a) of FIG. 4 is + ml ₂ Hc in the clockwise direction.
osθ, and the magnetic charge −m is similarly counterclockwise −ml ₁ Hcos θ. Of torque. Therefore, the resultant torque ｍ is m (l ₂ −l ₁ ) Hcos θ, that is, MHcos θ. (However, ± m is the magnetic charge, l ₁ and l ₂ are the distances from the fixed point O fixed by the housing to the magnetic charge ± m, M is the magnetization of the magnet 3, H is the strength of the magnetic field, θ is When the deflection angle is θ, the magnet 3 has a restoring moment k due to the elastic line.
also receives θ. (However, k is the spring constant of the elastic wire 1.) Further, when the magnet 3 swings at a high speed, dθ is determined by the frictional resistance with air and the frictional resistance inside the elastic wire.
A damping moment proportional to / dt is also received.
Then, when the torque is periodically applied at the angular frequency ω,
The magnet 3 with the elastic wire 1 and the fixing jig 4 start oscillating movement. When this vibration system is represented by a differential equation, the following equation is obtained. I · d ² θ / dt ² + C · d θ / dt + k · θ = MHco
sωt where θ: deflection angle I: inertia moment of elastic tensioned mechanical system with mass at the tip C: damping coefficient k: spring constant M: magnet magnetization H: magnetic field strength ω: frequency of alternating magnetic field t : Time This is a differential equation when a forcing force is applied to the damped oscillation system, and its general solution can be expressed by the following equation. θ = MH / I [(ω ₀ ² −ω ² ) ² +4 μ ² ω ² ] ^-1/2 cos
(Ωt−α) tan α = ² μω / ω ₀ ² −ω ² μ = C / 2I where ω ₀ : natural frequency or resonance frequency α: phase lag angle, that is, the frequency ω of the alternating magnetic field H and the mirror-finished magnet 3 ,
When the natural frequency ω _{0 of the} mechanical system composed of the fixing jig 4 and the elastic wire 1 having the spring constant k matches, resonance occurs,
It becomes the maximum deflection angle. Further, the phase delay angle at that time is α = 90 ° from the above equation. That is, although not shown, the current waveform flowing through the chip coil and the deflection angle waveform of the magnet 3 have a phase shift of 90 °. In the case of this embodiment, the applied voltage to the chip coil 6a is about 1 V, the current flowing through the chip coil is about 80 mA, and the alternating magnetic field frequency (ω
₀ ) At about 100 Hz, a resonance state occurred when the deflection angle in the X-axis direction (so-called scanning angle 2θ) was about 40 degrees. This also holds true for the interaction between the alternating magnetic field H and the magnetization M at the frequency ω ₀ generated in the chip coil 5a, and each interaction follows the vector operation rule (force composition rule). is there. That is, as shown in FIG.
Assuming that the alternating magnetic field in the axial direction is H _X = Hcosω ₀ t and the alternating magnetic field in the Y axis direction is H _Y = Hcos (ω ₀ t + β), (where β is the phase shift angle of the alternating magnetic field in the Y axis direction) When the alternating magnetic field and the alternating magnetic field in the Y-axis direction are in phase (β = 0
°), the magnet mirror-finished according to the force composition rule
It swings at an angle of 45 degrees with respect to the axis, and becomes a locus indicated by a dotted line in FIG. 5A. When the phases are shifted by 90 degrees, that is, when β = 90 °, the locus is shown in FIG. As shown in FIG. 5 (c), the trajectory becomes an ellipse shown in FIG. 5 (c) corresponding to the phase difference. Thus, by changing the phase difference β,
The movement of the mirror can be changed to a straight line, an ellipse, or a circle. That is, in the conventional example, two piezoelectric elements are separately vibrated in the X-axis direction and the Y-axis direction to draw a circle or an ellipse, but in the present invention, one magnet fixed to one elastic line is used. Has a structure that swings simultaneously in the X-axis direction and the Y-axis direction, so that there is no instability due to mechanical errors such as attachment of components. Given the delay angle β,
Extremely stable straight lines, circles, and ellipses can be drawn. Also, when the amplitudes (H _X , H _Y ) of the alternating magnetic field in the X-axis direction and the Y-axis direction are changed, the major axis of the ellipse rotates in the XY plane, and more various linear and elliptical motions Can be made. Then, the various swinging motions are enlarged and drawn on the projection surface by the laser light. Further, in the above example, the laser beam 12 was introduced to the surface 2 of the oscillating magnet by the stationary optical path conversion device 40. However, the mirror which oscillates the mirror using the optical path conversion device 40 in the same manner. By replacing the swinging device 30 with the swinging device 30 (FIG. 6) and swinging the mirror, it is possible to draw a complicated geometric pattern that further evokes the attention of the viewer. The mirror oscillating device 30 has the same configuration as the mirror oscillating unit 10 in the laser pointer configuration explanatory diagram of FIG.
The frequency and phase of the alternating current generators 35b and 36b are different from those of the mirror oscillating unit 10 . For example, when the optical path changing device 40 is replaced with a mirror rocking device 30, the mirror is made to make a small circular motion at 63 Hz, and the mirror-finished magnet 3 is made to make a small circular motion at 105 Hz. A geometric pattern as shown in FIG. 7A is drawn, and the mirror-oscillating device 30 is made to make a small circular motion at 240 Hz, and the mirror-finished magnet 3 is made to make a small circular motion at 130 Hz. It becomes a learning pattern and can further raise the viewer's attention. As described above, a small, inexpensive laser pointer with a wide drawing range can be realized by using an elastic wire, a mirror-finished magnet and a chip coil, despite a simple configuration. . The above-described embodiment is one example in which a laser pointer is realized, and various modifications can be made without departing from the spirit of the present invention.
For example, in the present invention, as the elastic wire, a shape memory alloy made of NiTi exhibiting super-elastic properties for larger swinging is adopted, but other materials, for example, phosphor bronze, which is famous as a spring material, or a tensile strength steel wire, Whisker (whisker crystal) of a certain piano wire, amorphous wire or pure iron
May be used. That is, the wire is not particularly limited as long as the wire is made of a material exhibiting elastic characteristics. The cross-sectional shape is not circular, but may be an elliptical wire having a different diameter, or a wire having another shape. Further, in the embodiment of the laser pointer according to the first aspect, a simple fixed mirror is used as the optical path changing device 40, but the laser is passed through an optical fiber, and the optical fiber
Is bent, and the light emitted from the optical fiber is guided to the mirror surface 2 of the magnet 3, so that it functions as the same optical path conversion device. In the above embodiment, a mirror-finished magnet is used. Instead, a mirror with magnet in which an ordinary optical mirror having a thickness of about 1 mm is fixed to a magnet having a thickness of about 1 mm with an adhesive or the like is used instead. It may be. Further, in the above embodiment, the fixing jig 4 is used to fix the mirror-finished magnet 3 and the elastic wire 1, but a magnetic material is adopted as the fixing jig material, and the surface thereof is mirror-finished. The three functions of mirror surface, magnet, and fixing may be replaced by one member.

As is apparent from the above description, according to the laser pointer of the first aspect, since the elastic axis having a high elastic limit is used for the oscillation axis for oscillating the mirror. In addition, one or more magnetic field generating means provided outside can greatly swing the magnet provided at the end of the elastic wire. Therefore, by introducing and reflecting the laser light on the mirror-finished surface of the oscillated magnet, the laser light is enlarged twice according to the law of reflection, and is reflected at a large angle, for example, a scanning angle of 40 degrees. Is drawn on the projection surface. That is, with the movement of the swing magnet on the projection surface,
A straight line or a curve can be drawn with a much wider width than the conventional example. According to the laser pointer of the second aspect, the elastic line is made of a shape memory alloy having a superelastic characteristic having a higher elastic limit. Shape memory alloys having superelastic properties have a much larger elastic limit than ordinary metals, and therefore can bend much more without being plastically or fractured even by a large external force. Therefore, by reflecting the laser light on the oscillating mirror, a straight line having a much larger width, for example, a scanning angle of 60 degrees or more, that is, a much wider width than that of the conventional or ordinary elastic wire is used. Or you can draw a curve. According to the laser pointer of the third aspect, the optical path changing device has an elastic line, a housing for fixing a rear end of the elastic line, and a mirror-finished surface at a front end of the elastic line. A mirror oscillating device that includes a magnet and a fixing jig, and oscillates the mirror-finished magnet with one or more magnetic field generating means provided outside.
Therefore, if an alternating magnetic field is generated by the magnetic field generating means provided in the mirror oscillating device, the mirror also oscillates, so that the laser light is transmitted to a plurality of oscillators having different frequencies. Reflection and projection are performed by the moving mirror, and a complicated geometric pattern can be drawn by the frequency difference or the swing amplitude difference, and the viewer's attention can be further enhanced. According to the laser pointer of the fourth aspect, a chip coil of several mm square having a core of ferrite or electromagnetic soft iron is used for the magnetic field generating means. In particular, so-called chip coils using ferrite are very cheap because they are mass-produced for communication devices. Therefore, much smaller and cheaper lasers
The pointer can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment according to claim 1 of the present invention.

FIG. 2 is a diagram illustrating a resonance state of an alternating magnetic field and a magnet having elastic lines.

FIG. 3 is a diagram showing an arrangement of a magnetic field and a magnetization M generated from a chip coil.

FIG. 4 is an explanatory diagram showing a torque Γ that a magnetization M receives from an alternating magnetic field H.

FIG. 5 is a diagram showing a swing pattern that changes due to a phase shift between an alternating magnetic field in the X-axis direction and an alternating magnetic field in the Y-axis direction.

FIG. 6 is a configuration diagram of a mirror oscillating device including an elastic wire, a magnet, and a chip coil.

FIG. 7 is a view showing a projection pattern of laser light reflected and projected by two oscillating mirrors having different frequencies.

FIG. 8 is a configuration diagram of a laser pointer using a conventional bimorph type piezoelectric element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Elastic wire 2 Mirror surface 3 Magnet 4 Fixing jig 5 Magnetic field generating means 6 Magnetic field generating means 9 Housing 11 Laser light generating means 12 Laser light 40 Optical path conversion device

Claims (4)

[Claims] 1. A laser for drawing a line or a curve by irradiating a laser beam on one or a plurality of oscillating mirrors and irradiating a light reflected by the oscillating mirror onto a projection surface. A pointer, a housing for fixing an elastic line, a rear end of the elastic line, a fixing jig for fixing a mirror-finished magnet at a distal end of the elastic line, and a fixing jig. A magnet fixed and mirror-finished to reflect laser light, one or more magnetic field generating means for rocking the magnet from outside, and a mirror surface of the magnet rocked by the magnetic field generating means And a light path changing device for introducing laser light to the laser pointer. 2. The laser pointer according to claim 1, wherein said elastic wire is made of a shape memory alloy having superelastic properties. 3. An optical path changing device comprising: an elastic wire; a housing for fixing a rear end of the elastic wire; and a fixing jig for fixing a mirror-finished magnet at a front end of the elastic wire. A magnet fixed by the fixing jig and mirror-finished to reflect laser light, and one or more magnetic field generating means for swinging the magnet from outside. Claim 1 or Claim 2
Laser pointer described in 4. The magnetic field generating means comprises a core coil made of fine ferrite or micro-electromagnetic soft iron, a chip coil having a conductive wire wound around the core, and an alternating current generator for supplying an alternating current to the coil. Claim 1 to Claim 3
Laser pointer described in