JPH09329758A - Optical scanner and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical scanner whose durability is extremely excellent and which is easily manufactured, and the manufacturing method thereof. SOLUTION: A torsion spring 5 is provided with housing fixing parts 12 at both end parts and a plane magnet fitting part 13 at the central part. Then, a magnet 3 is fitted to one side surface of the fitting part 13 and the other surface is provided with a mirror 15. The spring 5 is supported by a housing 1 at the fixing part 12. Besides, the mirror 15 reflecting a laser light beam 10 emitted from a light source 31 and the magnet 3 are supported at the fitting part 13 so that they can be oscillated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device used for office equipment such as a laser printer, a bar code reader, a laser scanning micrometer, and a measuring instrument, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, as an optical scanning device having a mirror with a magnet and a coil for generating an alternating magnetic field, for example, an optical scanning device having a structure shown in FIG. 7 is known.

In the conventional optical scanning device, as shown in FIG. 7, a torsion spring 5 made of a shape memory alloy wire or the like is used.
0 is fixed to the housing 1 by a fixing jig 52 while being pulled by an appropriate tension. At approximately the center of the torsion spring 50, a mirror 53 with a magnet, which is mirror-finished on at least one surface of the magnet, is fixed with an adhesive (not shown).

On the other hand, a coil 7 is wound around the core 6. The coil 7 is fixed to the housing 1 with a screw through a screw hole 8 provided in the core 6 and a hole 4 provided in the housing 1. Then, when a predetermined current is applied to the coil from the pulse current generator 9, an alternating magnetic field is generated and the mirror 53 with a magnet vibrates. The laser light 10 emitted from a light source (not shown) is a mirror 53 with a magnet.
When the mirror 53 with a magnet resonates, the surface to be scanned (not shown) is scanned.

[0005]

However, in the conventional optical scanning device, the mirror 53 with the magnet is attached to the torsion spring 5.
Since it is fixed to 0 with an adhesive or the like, the fixing force between the two gradually decreases during driving, and eventually the mirror with magnets slips or falls off, which causes the durability of the device to be significantly reduced. . The magnet-equipped mirror 53 is manufactured by mechanically mirror-polishing at least one surface of the magnet. However, because of the fact that cutting dust adheres to the polishing surface during polishing and causes new scratches, etc. There was a problem that mirror finishing was very difficult.

The optical scanning device of the present invention has been made to solve the above-mentioned problems, and an object thereof is to provide an optical scanning device having extremely excellent durability and easy to manufacture, and a manufacturing method thereof. To do.

[0007]

In order to achieve this object, an optical scanning device according to a first aspect of the present invention is characterized in that both ends are supported by a housing and a central part emits a light beam emitted from a light source. The elastic member for swingably supporting the reflecting portion for reflecting and the magnet is targeted, and in particular, the elastic member has a fixing portion supported by the housing at the both end portions and a flat surface at the central portion. Each of the magnet mounting portions is provided, the magnet is mounted on one side surface of the magnet mounting portion, and the reflecting portion is provided on the other side surface. Therefore, the elastic member is securely fixed to the housing at the fixing portion. Further, the magnet is securely attached to the one side surface of the magnet attachment portion with a strong fixing force, and the magnet does not fall off during driving. On the other hand, since the reflecting portion is provided on the other side surface, the reflecting portion can be provided separately from the magnet, and the reflecting portion can be easily formed without the need for mirror polishing the magnet.

According to a second aspect of the present invention, in the optical scanning device, the reflecting portion is mirror-finished on a surface of the magnet mounting portion opposite to a surface on which the magnet is mounted. Therefore, it is not necessary to mirror-polish the magnet, and it is not necessary to separately form the reflecting portion and attach it to the opposite surface.

In the method of manufacturing an optical scanning device according to a third aspect of the present invention, both ends are supported by the housing, and the central portion is capable of swinging the reflecting portion for reflecting the light beam emitted from the light source and the magnet. A method of manufacturing an optical scanning device having an elastic member supported on, wherein a resist layer corresponding to the planar shape of the elastic member is formed on a thin plate having elasticity, and the resist layer is not formed. The parts are melted by electropolishing to form fixing parts supported by the housing at the both ends and the magnet mounting part at the central part, respectively, and then a reflecting part is formed on one side surface of the magnet mounting part. And the magnet is adhesively fixed to the other side. Therefore, the portion where the resist layer of the elastic thin plate is not formed is uniformly dissolved, and the fixing portion and the magnet mounting portion are formed with high accuracy and easily by the electrolytic polishing method,
Further, the reflecting portion can be provided on one side surface of the magnet mounting portion, and the magnet can be securely attached to the other side surface.

According to a fourth aspect of the present invention, in the method of manufacturing an optical scanning device, the reflecting portion is formed by bonding and fixing a mirror to a surface of the magnet mounting portion opposite to a surface on which the magnet is mounted. . Therefore, it is not necessary to carry out mirror polishing of the magnet, and the reflecting portion can be easily formed by a mirror manufactured separately.

According to a fifth aspect of the present invention, there is provided a method of manufacturing an optical scanning device, wherein the reflecting portion is mirror-polished by electropolishing on a surface of the magnet mounting portion opposite to a surface on which the magnet is mounted. Form. Therefore, it is not necessary to carry out mirror polishing of the magnet, and it is not necessary to separately manufacture and bond and fix the mirror, and it is possible to easily form the reflecting portion with high accuracy.

In the method of manufacturing the optical scanning device according to the sixth aspect, a shape memory alloy is used as the thin plate.
Therefore, it is possible to manufacture an optical scanning device that is extremely elastic and has excellent durability.

According to a seventh aspect of the present invention, there is provided a method of manufacturing an optical scanning device, wherein the shape memory alloy is a Ti-Ni type shape memory alloy, and the electrolytic polishing method is electrolytic polishing of a perchloric acid / acetic acid solution. Used as a liquid. Therefore, a thin plate made of a Ti-Ni-based shape memory alloy, in which the resist layer is not formed, is uniformly dissolved in a perchloric acid / acetic acid solution, and the light is excellent in elasticity and durability. A scanning device can be manufactured.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a torsion spring 5 used in the optical scanning device according to the first embodiment of the present invention. This torsion spring 5 is made of Ti with a thickness of about 0.2 mm.
It is made of a Ni-based shape memory alloy, and includes a spring portion 11, a housing fixing portion 12, and a magnet mounting portion 13. Spring part 11
Has a width of about 0.1 to 0.6 mm, and the torsion spring 5
The housing fixing parts 12 provided at both ends are spring parts 11.
It is formed to be larger and has a screw hole for fixing to the housing. A magnet mounting portion 13 is provided at a substantially central portion of the torsion spring 5. The size of the magnet mounting portion 13 is almost the same as the size of the magnet 3 to be mounted, and is about 3 mm in length and 6 mm in width. The torsion spring 5 constitutes the elastic member of the present invention.

Next, the configuration of the optical scanning device of the present embodiment is shown in FIG. The torsion spring 5 having the above structure is fixed to the housing 1 by the fixing jig 2 at the housing fixing portion 12 while being pulled by an appropriate tension. The torsion spring 5 has a thickness of about 0.2 as described above.
mm spring made of Ti-Ni type shape memory alloy, spring part 1
1, a housing fixing portion 12 and a magnet mounting portion 13. The magnet 3 is fixed to one surface of the magnet mounting portion 13 at the center of the torsion spring 5 with an adhesive agent (not shown).
The magnet 3 is made of Ni-Co alloy or Sm-Co alloy, and its size is about 3 mm in length, 6 mm in width, and 0.3 mm in thickness. Further, a mirror 15 having the same size as the magnet 3 is adhered and fixed to the other surface of the magnet mounting portion 13. The mirror 15 constitutes the reflection part of the present invention.

On the other hand, the core 6 is arranged so as to face the magnet 3. A coil 7 is wound around the core 6, for example, about 300 turns. Coil 7
Are fixed to the housing 1 with screws (not shown) through screw holes 8 provided in the core 6 and holes 4 provided in the housing 1. With the pulse current generator 9,
For example, when an electric current of about 100 mA at 3 V is passed through the coil 7, an alternating magnetic field is generated and the magnet 3 vibrates. At the same time, the mirror 15 fixed to the back surface also vibrates. The laser light 10 emitted from the light source 31 arranged so as to face the mirror 15 is reflected by the mirror 15, and the mirror 15 resonates together with the magnet 3 so that the surface to be scanned 32 is scanned. The laser light 10 constitutes the light beam of the present invention.

Next, FIG. 3 shows an optical scanning device according to a second embodiment of the present invention. The same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the optical scanning device of the second embodiment, in the magnet mounting portion 13 of the torsion spring 5, the surface opposite to the surface on which the magnet 3 is mounted is mirror-polished and the reflecting portion 15 is formed.
It is formed as a. The reflecting portion 15a can be formed by ordinary mechanical polishing, but can also be formed by an electrolytic polishing method described later. If the magnet mounting portion 13 itself is processed as the reflecting portion in this manner, there is an advantage that it is not necessary to separately manufacture the mirror 15 and adhere and fix it to the magnet mounting portion 13.

Next, a method of manufacturing the torsion spring 5 by electrolytic polishing will be described with reference to FIG.

First, as shown in FIG. 4A, the thickness is about 0.
Ti-Ni-based shape memory alloy plate 21 of about 2 mm (hereinafter,
A resist layer 22 is formed on the alloy plate 21 to have the same size and shape as the desired torsion spring 5.
The resist layer 22 is a shaded portion in the figure. Further, a lead wire 23 for applying a voltage is attached by electropolishing, and the resist layer 22 is also applied to the attaching portion so as to be continuous with the portion where the resist layer 22 is formed. It is preferable to provide as many lead wires 23 as possible in order to uniformly electropolish the entire alloy plate 21, but it is possible to perform electropolishing at least at one location. Further, the position where the lead wire 23 is attached is not particularly limited. In FIG. 4, for convenience, an example is shown in which the lead wire 23 is provided at a position corresponding to two housing fixing portions. Although only one surface of the alloy plate 21 is illustrated in FIG. 4A, the resist layer 22 is actually formed at the same position on both front and back surfaces of the alloy plate 21. The alloy plate 21 constitutes the thin plate of the present invention.

Next, as shown in FIG. 4 (b), the alloy plate 21 on which the resist layer 22 is formed is placed in an electrolytic polishing solution 27, and the lead wire 23 is dc so that the alloy plate 21 serves as an anode. Connect to power supply 24. Then, at least two cathode plates 25 are arranged so as to face the front and back surfaces of the alloy plate 21, and are connected to the cathode side of the DC power supply 24. As the cathode plate 25, a platinum plate or a stainless plate is used. It is desirable that the cathode plate 25 be arranged so as to cover the entire side wall of the bath 26. A perchloric acid / acetic acid solution is used as the electrolytic polishing liquid 27, and its composition is, for example, 5% perchloric acid / 95% acetic acid. When a predetermined voltage is applied from the DC power source 24 in this state, the portion of the alloy plate 21 where the resist layer 22 is not formed is gradually dissolved, and finally the resist layer 22 is formed as shown in FIG. 4C. Only the broken portion and the lead wire 23 remain. The applied voltage is 5 to 30 V, and for example, when a voltage of 20 V is applied, a desired shape is obtained in about 2 to 3 hours.

Finally, the lead wire 23 and the unnecessary portion extending therethrough are cut and removed, and the resist layer 22 is further removed to complete the torsion spring 5 as shown in FIG.

Further, in the optical scanning device of the second embodiment, when the magnet mounting portion 13 of the torsion spring 5 is mirror-polished by electrolytic polishing to form the reflecting portion 15a, FIG.
As shown in, a torsion spring shaped alloy plate 21
With the resist layer 22 on at least one surface above removed, the alloy plate 21 is again placed in the electrolytic polishing liquid 27 in the same manner as in the above state, as shown in FIG. 4B. Then, although it depends on the degree of surface roughness, when electrolytic polishing is performed for 0.5 to 2 hours at an applied voltage of 1 to 10 V, the surface of the alloy plate 21 is mirror-finished to complete the reflecting portion 15a.

The manufacturing method may be modified in various ways without departing from the spirit of the invention.

For example, the composition of the electrolytic polishing liquid 27 can be freely changed, and if necessary, the liquid is heated to 30 to 5
If it is carried out at about 0 ° C., the melting rate of the alloy plate 21 will increase. Further, the electrolytic polishing liquid 27 may be appropriately stirred or the alloy plate 2
When 1 is rocked, vibrated, or rotated, the alloy plate 21 can be more uniformly melted, and the torsion spring can be manufactured with high accuracy.

Further, the arrangement of the alloy plate 21 and the cathode plate 25 is not limited to the arrangement shown in FIG. 4 (b). For example, the alloy plate 21 is arranged horizontally with respect to the liquid surface, and the cathode plate 25 is arranged so as to face the alloy plate 21, that is, two cathode plates 25 are provided near the bottom of the bath 26 and near the liquid surface. It may be placed at.

Furthermore, in the above-mentioned manufacturing method, an example of electrolytic polishing with a constant potential has been described, but it is also possible to carry out this with a constant current. In particular, when the area of the melted portion is larger than the area of the torsion spring, it is possible to manufacture the torsion spring with higher accuracy by carrying out with a constant current. The constant current condition depends on the area and shape of the alloy plate 21 and the torsion spring 5 to be produced, but the current density is about 0.5 to 5 A / dm ² .

Next, the operation of the optical scanning device of each of the above embodiments will be described.

Now, when a pulse current as shown in FIG. 2 is passed through the coil 7, the coil 7 is forward and backward shown in FIG.
A so-called alternating magnetic field is generated as shown in FIGS. The center of the magnet 3 is fixed to the torsion spring 5, and the magnet 3 installed in front of the coil 7 receives a torque of MH cos θ due to the alternating magnetic field. (M is the magnetic moment of the magnet, H is the strength of the magnetic field, θ is the deflection angle) Further, in the case of the torsion angle θ, the restoring force by the torsion spring 5 and kθ are also simultaneously received (k: spring constant).

Further, when the magnet 3 vibrates at high speed, a damping force proportional to dθ / dt is also received due to the frictional resistance with the air and the frictional resistance inside the torsion spring 5. Then, when the torque is applied periodically (angular frequency ω), the magnet 3 starts torsional vibration. When this vibration system is expressed by an equation, Equation 1 is obtained.

[0032]

[Equation 1]

This is an equation in the case where a forcing force is applied to the damping vibration system, and its general solution is expressed by equation (2).

[0034]

[Equation 2]

That is, when the frequency ω of the current and the natural frequency ω ₀ of the mechanical system composed of the magnet 3 and the torsion spring 5 match, a so-called resonance state occurs and the maximum deflection angle is obtained. In the case of the present embodiment, the voltage 3 applied to the coil 7
V, coil current about 100mA, magnet 3 at about 800Hz
Resonates, and the deflection angle is about 50 degrees, that is, the scanning angle is about 100 degrees, and the laser light is scanned by the mirror 15 attached to the back surface of the magnet 3.

In the above embodiment, the scanning angle is about 100 degrees and the scanning frequency is 800 Hz. However, the optical scanning device of various frequencies can be manufactured by changing the plate thickness t of the torsion spring and the mass m of the magnet. You can For example, when manufacturing an optical scanning device of 400 Hz, the frequency f is proportional to (k / m) ^1/2 , and the spring constant k is proportional to t ³ , so t 3/2 is proportional to the frequency. become. Since the resonance frequency was 800 Hz at t = 200 μm, an optical scanning device at about 400 Hz can be manufactured by using a torsion spring of about t = 125 μm under the same conditions as above.

Further, as can be seen from the coefficient MH / I of Equation 2, by using magnets of various strengths (M),
Alternatively, an optical scanning device having a desired scanning angle according to a target electric product or electronic device can be provided by giving a magnetic field of various amplitudes (H = ni, n: number of coil windings i: current), that is, a current i. It can be created.

In the present invention, the waveform of the current flowing through the coil 7 is a rectangular wave. This is because, as shown in FIG. 5, the torque applied to the magnet by the twist angle θ becomes MHcos θ, and the alternating magnetic field Hcos θ acts on the magnetic moment M of the magnet. Is.

FIG. 6 shows the torsion angle θ of the magnet associated with the rectangular wave current.
The state of vibration of is shown. From Equation (2-2), when ω = ω ₀ , α = 90 °, that is, θ is 90 ° with respect to the alternating magnetic field.
There will be a phase delay. That is, 90 ° from the switching of the magnetic field
When it is delayed, the torsion angle θ of the magnet becomes maximum, and by extension, the restoring force kθ (k: spring constant) by the torsion spring 5
Is also the largest. The points a, b, c, d of the current waveform correspond to the vibration states (a), (b), (c), (d) of the magnet 3, respectively. When the rectangular wave is used, torque can be applied to the magnet 3 until the restoring force of the torsion spring 5 is maximized, so that the scanning width can be maximized as compared with other current waveforms. However, if there is a margin in the scan width, SIN
Even a periodic waveform such as a wave or a triangular wave can be sufficiently scanned. Further, in the present embodiment, the present optical scanning device is configured by utilizing the resonance phenomenon in order to minimize the current flowing through the coil 7, but if the power has a margin, the optical scanning device is driven by removing the resonance point. However, there is no functional problem.

[0040]

As is apparent from the above description, in the optical scanning device according to the first aspect of the present invention, both ends are supported by the housing and the central part reflects the light beam emitted from the light source. The elastic member for swingably supporting the reflecting portion and the magnet is targeted, and in particular, the elastic member has a fixing portion supported by the housing at the both end portions and a planar shape at the central portion. Each has a magnet mounting part,
The magnet is attached to one side surface of the magnet attaching portion, and the reflecting portion is provided on the other side surface. Therefore, the elastic member is
The fixed portion is securely fixed to the housing. Further, the magnet is securely attached to the one side surface of the magnet attachment portion with a strong fixing force, and the magnet does not fall off during driving. On the other hand, since the reflecting portion is provided on the other side surface, the reflecting portion can be provided separately from the magnet,
The reflecting portion can be easily formed without the need for mirror-polishing the magnet.

Further, in the optical scanning device according to a second aspect of the present invention, the reflecting portion is a mirror-finished surface of the magnet mounting portion opposite to the surface on which the magnet is mounted. Therefore, it is not necessary to mirror-polish the magnet, and it is not necessary to separately form the reflecting portion and attach it to the opposite surface.

In the method of manufacturing an optical scanning device according to a third aspect of the present invention, both ends are supported by the housing, and the central portion can swing the reflecting portion for reflecting the light beam emitted from the light source and the magnet. A method of manufacturing an optical scanning device having an elastic member supported on, wherein a resist layer corresponding to the planar shape of the elastic member is formed on a thin plate having elasticity, and the resist layer is not formed. The parts are melted by electropolishing to form fixed parts supported by the housing at the both ends and the magnet mounting part at the central part, respectively, and then a reflecting part is formed on one side surface of the magnet mounting part. And the magnet is adhesively fixed to the other side. Therefore, the portion where the resist layer of the elastic thin plate is not formed is uniformly dissolved, and the fixing portion and the magnet mounting portion are formed with high accuracy by electropolishing, and easily,
Further, the reflecting portion can be provided on one side surface of the magnet mounting portion, and the magnet can be securely attached to the other side surface.

According to a fourth aspect of the present invention, in the method of manufacturing an optical scanning device, the reflecting portion is formed by bonding and fixing a mirror to the surface of the magnet mounting portion opposite to the surface on which the magnet is mounted. . Therefore, it is not necessary to carry out mirror polishing of the magnet, and the reflecting portion can be easily formed by a mirror manufactured separately.

According to a fifth aspect of the present invention, there is provided a method of manufacturing an optical scanning device in which the reflection portion is mirror-polished by electropolishing on a surface of the magnet mounting portion opposite to a surface on which the magnet is mounted. Form. Therefore, it is not necessary to perform mirror polishing of the magnet, and it is not necessary to separately manufacture the mirror and adhere and fix the mirror, and it is possible to easily form a highly accurate reflecting portion.

Further, in the method of manufacturing the optical scanning device according to the sixth aspect, a shape memory alloy is used as the thin plate.
Therefore, it is possible to manufacture an optical scanning device that is extremely elastic and has excellent durability.

According to a seventh aspect of the present invention, there is provided a method of manufacturing an optical scanning device, wherein the shape memory alloy is a Ti—Ni type shape memory alloy, and the electrolytic polishing method is electrolytic polishing of a perchloric acid / acetic acid solution. Used as a liquid. Therefore, a thin plate made of a Ti-Ni-based shape memory alloy, in which a resist layer is not formed, is uniformly dissolved in a perchloric acid / acetic acid solution, and thus a light having excellent elasticity and durability is used. A scanning device can be manufactured.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a torsion spring used in an optical scanning device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of an optical scanning device.

FIG. 3 is a perspective view showing an optical scanning device according to a second embodiment.

FIG. 4 is an explanatory diagram showing a method of manufacturing a torsion spring.

FIG. 5 is a schematic diagram in which a magnet and a mirror receive torque from an alternating magnetic field.

FIG. 6 is a diagram showing how a magnet and a mirror vibrate with a rectangular wave current.

FIG. 7 is a perspective view showing a configuration of a conventional optical scanning device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 3 Magnet 5 Torsion spring 11 Spring part 12 Housing fixing part 13 Magnet mounting part 15 Mirror 15a Reflecting part 10 Laser beam 31 Light source 21 Alloy plate 22 Resist layer 27 Electropolishing liquid

Claims (7)

[Claims] 1. An optical scanning device comprising an elastic member, both ends of which are supported by a housing, and a central portion of which is oscillatably supported by a reflecting portion for reflecting a light beam emitted from a light source and a magnet. The elastic member has fixed portions supported by the housing at both ends thereof, and a flat magnet mounting portion at the central portion thereof. The magnet is mounted on one side of the magnet mounting portion and reflected on the other side. An optical scanning device having a section. 2. The optical scanning device according to claim 1, wherein the reflecting portion is formed by mirror-finishing a surface of the magnet mounting portion opposite to a surface on which the magnet is mounted. 3. A method of manufacturing an optical scanning device comprising both ends of which are supported by a housing, and a central portion of which is provided with an elastic member which swingably supports a reflecting portion for reflecting a light beam emitted from a light source and a magnet. A resist layer corresponding to the planar shape of the elastic member is formed on an elastic thin plate, and a portion where the resist layer is not formed is dissolved by an electropolishing method, and the housing is provided at both ends. The magnet mounting portion is formed in the central portion, and thereafter, the reflecting portion is provided on one side surface of the magnet mounting portion and the magnet is adhesively fixed to the other side surface. Method for manufacturing optical scanning device. 4. The optical scanning device according to claim 3, wherein the reflecting portion is formed by bonding and fixing a mirror to a surface of the magnet mounting portion opposite to a surface on which the magnet is mounted. Manufacturing method. 5. The light according to claim 3, wherein the reflecting portion is formed by mirror-polishing a surface of the magnet mounting portion opposite to a surface on which the magnet is mounted by an electrolytic polishing method. Manufacturing method of scanning device. 6. The method of manufacturing an optical scanning device according to claim 3, wherein the thin plate is made of a shape memory alloy. 7. The shape memory alloy is a Ti—Ni-based shape memory alloy, and the electrolytic polishing method uses a perchloric acid / acetic acid solution as an electrolytic polishing liquid. Manufacturing method of optical scanning device.