JPH07181414A - Optical scanner - Google Patents

Abstract

PURPOSE:To inexpensively provide an optical scanner which is small in size and long in life and with which a large scanning angle is obtainable with a low voltage. CONSTITUTION:A plate 9 consisting of an elastic deformation part 3, a vibration input part 4 which is disposed at one end of this elastic deformation part 3 and a mirror supporting part 8 which is disposed at the other end thereof and has nearly an inverted L shape is formed integrally from a beryllium copper alloy or stainless steel SUS 631 by pressing, etc. At this time, this plate is so formed that the ratio L/T of the thickness T and length L of the elastic deformation part 3 attains 100>=L/T>=50 and the thickness T and the width W attain W>=T. A juncture 11 of the elastic deformation part 3 with the vibration input part 4 and a i uncture 11 of the elastic deformation part 3 with the mirror supporting part 8 are provided with corners 10a, 11a having such an approximate arc shape that its radius R attains 1<R/W<2. The optical scanner 1 is formed by providing the mirror supporting part 8 with a mirror 7 and providing the vibration input part 4 with a driving source 6, such as piezoelectric element.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to optical scanners. Specifically, it relates to an optical scanner that linearly scans light in a laser printer, a bar code reader, or the like.

[0002]

2. Description of the Related Art In order to meet the demand for smaller and lighter optical parts, the applicant has made a small and light vibrator (15 mm in length and width, 0.1 mm in thickness) produced by etching a single crystal silicon substrate.
We have proposed an optical scanner that can scan in a two-dimensional direction with 5 mm and a weight of 0.08 g) that resonates with a piezoelectric element.

This conventional optical scanner is shown in FIGS. 6 and 7. Transducer 5 used in the optical scanner 51 shown in FIG.
2 is bending direction (θ _B direction) and twist direction (θ _T direction)
A vibration input unit 54 is provided at one end of the elastic deformation unit 53 having an elastic deformation mode, a scanning unit 55 for reflecting a light beam is provided at the other end, and a scanning unit 55 is provided at one sleeve of the scanning unit 55.
Inertia moment generating blades 56 for increasing the inertia moment are formed. A piezoelectric element 57 is attached to the vibration input section 54 of the vibrator 52, and when a vibration having a frequency equal to the resonance frequency f _B of the bending deformation mode of the elastic deformation section 53 is applied from the piezoelectric element 57 to the vibration input section 54. When the scanning unit 55 rotates in the θ _B direction and a vibration having a frequency equal to the resonance frequency f _T of the torsional deformation mode of the elastic deformation unit 53 is applied from the piezoelectric element 57 to the vibration input unit 54, the scanning unit 55 rotates by θ _T. Rotate in the direction. When the scanning unit 55 is irradiated with the light beam, the reflected light is scanned in the θ _B direction or the θ _T direction.

Further, the scanning portion 55 of the vibrator 52 used in the optical scanner 61 shown in FIG. 7 has a shape that is substantially symmetrical with respect to the axis P of the elastically deforming portion 53, and the surface thereof is A mirror-finished mirror surface 58 is formed, and a weight (eccentric load) 59 is attached to the side end of the back surface. Therefore, the optical scanner 51 shown in FIG. 6 has a shape in which the moment of inertia wing 56 is removed, and the size of the scanning unit 55 is made as small as possible (for example, 5 mm or less in each length and width) so that the air resistance can be sufficiently ignored. Has been

[0005]

SUMMARY OF THE INVENTION These optical scanners 5
As a material of the oscillator 52 used in the Nos. 1 and 61, mainly S
i (silicon) and stainless steel SUS304 have been used.

Since Si has a small damping coefficient, Si has an advantage that a large scanning angle can be obtained even when the voltage applied to the vibration source, that is, the piezoelectric element 57, is low, but on the other hand, the vibrator 52 formed using Si has the advantage. As a result, there is a problem in that, when a drop impact is applied, the impact wave or the like causes the elastic deformation portion 53 to be broken even if it is within the elastic limit. Also, the material cost of Si wafer is stainless steel SUS30.
There were also problems such as being higher than 4.

On the other hand, SUS304 does not break due to impact and there is no problem on the impact surface. However, since SUS304 has a larger damping coefficient than Si, it is necessary to apply a large voltage to the piezoelectric element 57, and the power source can be downsized. It is not preferable in terms of low power consumption.

Further, since SUS304 is a metal material, there is a problem that fatigue fracture occurs after long-term use. From this point, there is a problem that the scanning angle must be reduced and the size of the vibrator 52 must be increased in order to allow the vibrator 52 to withstand high speed and long-term use. . This problem will be specifically described below.

The one shown in FIG. 8 (a) is called an SN curve or a Wahra curve. This SN curve is shown in FIG.
As shown in (b), for example, in a case where a stress is repeatedly applied to a certain portion (elastically deformable portion 53) like the above-mentioned vibrator 52, the upper limit stress is S ₁ and the lower limit stress is S _2. , Sm = (S ₁ + S ₂ ) / 2 is the average stress, Sa = (S ₁
It is applied when the average stress Sm is constant, where −S ₂ ) / 2 is used as the stress amplitude, and the stress amplitude Sa is plotted on the vertical axis until the part under the stress amplitude Sa is broken. It is the figure which showed the stress repetition number N on the horizontal axis (logarithmic scale).

The failure of the oscillator 52 is caused by the stress amplitude Sa generated in the oscillator 52 as represented by the SN curve in FIG.
And the number of repetitions N. Here, the stress amplitude Sa and the number of repetitions N are expressed by the following equations and equations, respectively. Sa = α × T × E × θ / L ...... N = f × t ... where α is a constant determined by the cross-sectional shape of the elastically deformed portion, T is the thickness of the elastically deformed portion, and E is the Young's modulus of the material. , Θ is the scanning angle of the vibrator, L is the length of the elastically deformable portion, f is the drive frequency (resonance frequency f of the vibrator), and t is the operating time.

The resonance frequency f of the vibrator is expressed by the following equation. f = √ (K / I) / 2π Here, K is the spring constant of the oscillator, I is the moment of inertia, and K is expressed by the following equation. K = β × W × T ³ × E / L, where β is a proportional constant and W is the width of the elastically deformable portion.

According to FIG. 8A, in order to use the vibrator at high speed (increasing the frequency f) and for a long time (increasing t), that is, in order to use it with a large number of repetitions N, the material is It is necessary to reduce the applied stress amplitude Sa. Here, in order to reduce the stress amplitude Sa,
As can be seen from the formula, the following four methods are possible.

(A) The scanning angle θ of the vibrator is reduced. (A) The thickness T of the elastically deformable portion is reduced. (C) Increase the length L of the elastically deformable portion. (D) Use a material having a small Young's modulus E.

However, the use of these methods causes the following problems. In other words, (a) Reducing the scanning angle θ of the vibrator leads to deterioration of the function of the optical scanner. (B) When the thickness T of the elastically deforming portion is made thin, the spring constant K of the vibrator becomes small as can be seen from the equation and the equation, the resonance frequency f is remarkably lowered, and high-speed scanning cannot be performed. (C) When the length L of the elastically deformable portion is increased, the size of the vibrator becomes larger. (D) If a material having a small Young's modulus E is made small, the spring constant K of the vibrator becomes small as can be seen from the equation and the equation, and the resonance frequency f is lowered to make high-speed scanning impossible.

As described above, the use at high speed for a long time (long life) causes a reduction in the scanning angle for the above reasons, which is contrary to the miniaturization of the optical scanner.

The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and an object thereof is to provide an inexpensive optical scanner which is small in size, has a long life, and has a large scanning angle at a low voltage. To provide in.

[0017]

A first optical scanner according to the present invention is provided with an elastic deformation portion having at least one elastic deformation mode and one end of the elastic deformation portion for elastically deforming applied vibration. A vibration input unit that transmits the vibration input unit, a scan unit that is provided at the other end of the vibration input unit and that rotates according to the elastic deformation mode of the elastic deformation unit, and a vibration source that applies vibration to the vibration input unit. In an optical scanner equipped with
The ratio L / T of the thickness T of the elastically deformable portion and the length L of the elastically deformable portion is set to approximately 100 ≧ L / T ≧ 50.

A second optical scanner of the present invention is an elastic deformation part having at least one elastic deformation mode, and a vibration input part provided at one end of the elastic deformation part and transmitting the applied vibration to the elastic deformation part. And an optical scanner including a scanning unit that is provided at the other end of the vibration input unit and that rotates according to an elastic deformation mode of the elastic deformation unit, and a vibration source that applies vibration to the vibration input unit. A substantially arc-shaped corner is formed at an inner corner between the elastically deformable portion and the vibration input portion or at an inner corner between the elastically deformable portion and the scanning portion,
The ratio R / W of the width W of the elastically deformable portion and the radius R of the corner is set to 1 <R / W <2.

A third optical scanner of the present invention is an elastic deformation section having at least one elastic deformation mode, and a vibration input section provided at one end of the elastic deformation section and transmitting applied vibration to the elastic deformation section. And an optical scanner including a scanning unit that is provided at the other end of the vibration input unit and that rotates according to an elastic deformation mode of the elastic deformation unit, and a vibration source that applies vibration to the vibration input unit. The end portion of the elastically deformable portion on the side of the vibration input portion is located at the center of the surface of the vibration source.

According to a fourth optical scanner of the present invention, an elastic deformation portion having at least one elastic deformation mode and a vibration input portion provided at one end of the elastic deformation portion and transmitting the applied vibration to the elastic deformation portion. And an optical scanner including a scanning unit that is provided at the other end of the vibration input unit and that rotates according to an elastic deformation mode of the elastic deformation unit, and a vibration source that applies vibration to the vibration input unit. At least the elastically deformable portion is made of a metal material having a small damping coefficient, such as a copper alloy, an aluminum alloy, or a titanium alloy. Especially beryllium copper alloy and stainless steel SUS6
It is preferable to create it by 31. Furthermore, it is preferable to use a material that does not require age hardening after processing.

A fifth optical scanner of the present invention is an elastic deformation part having at least one elastic deformation mode, and a vibration input part provided at one end of the elastic deformation part and transmitting applied vibration to the elastic deformation part. And an optical scanner including a scanning unit that is provided at the other end of the vibration input unit and that rotates according to an elastic deformation mode of the elastic deformation unit, and a vibration source that applies vibration to the vibration input unit. The scanning unit includes a mirror unit for reflecting a light beam and a mirror supporting unit for supporting the mirror unit having an area smaller than the area of the mirror unit, and the mirror supporting unit has one end of the elastic deformation unit. It is characterized by being installed in. At this time, so that the center of gravity of the scanning unit deviates from the central axis of the elastically deforming unit,
It is desirable that the shape of the mirror support is asymmetric with respect to the central axis.

In each of the optical scanners described above, the relationship between the thickness T of the elastically deformable portion and the width W of the elastically deformable portion is W ≧ T.
It is good to say

[0023]

According to the first optical scanner of the present invention, the ratio L / T of the thickness T of the elastically deformable portion to the length L thereof is approximately 100 ≧ L / T ≧.
Since the stress amplitude Sa related to the fatigue strength is kept low, the spring constant K of the oscillator related to the resonance frequency f can be kept large, and the length L of the elastically deformable portion can be shortened. . Therefore, it is possible to provide a small-sized optical scanner capable of long life and high-speed scanning.

Further, in the second optical scanner of the present invention, substantially arc-shaped corners are formed at the inner corners of the elastically deforming portion and the vibration input portion or at the inner corners of the elastically deforming portion and the scanning portion, Since the ratio R / W of the width W of the elastically deformed portion and the radii R of these corners is set to 1 <R / W <2, stress concentration generated in the vibrator is relaxed and damage due to stress concentration is reduced. The life of the optical scanner can be extended.

Further, in the third optical scanner of the present invention, since the end portion of the elastically deformable portion on the side of the vibration input portion is located substantially in the center of the surface of the vibration source, the stress amplitude Sa and the vibration of the vibrator are reduced. The total length of the vibrator can be shortened without changing the length L of the elastically deformable portion related to the spring constant K, and the optical scanner can be downsized.

Further, like the fourth optical scanner of the present invention, if at least the elastically deformable portion is made of a metal material having a small damping coefficient such as a copper alloy, an aluminum alloy, or a titanium alloy, it is vibrated even by a shock such as dropping. The child is not damaged, and a large scanning angle can be obtained with a small exciting force. Therefore, the vibration source can be downsized and the voltage of the vibration source can be lowered, and the downsizing and power saving of the optical scanner can be facilitated.

Among them, the beryllium copper alloy among copper alloys has not only a small attenuation coefficient but also a large fatigue strength, so that the life of the optical scanner can be extended. Furthermore, if age hardening treatment after processing is unnecessary as these materials, for example, a mill-hardened material is used, there is no fear of deformation such as warping of the vibrator during heat treatment after processing, and a vibrator with less variation can be obtained. Can be provided. In addition, SUS which is a kind of precipitation hardening stainless steel
Even if 631 is used, the same effect as that of the beryllium copper alloy can be obtained.

In the fifth optical scanner of the present invention, since the scanning section is composed of the mirror section and the mirror supporting section for supporting the area mirror section smaller than the area of the mirror section, the mirror supporting section is a mirror. It is possible to reduce the weight of the scanning unit and reduce the moment of inertia of the vibrator by configuring the scanning unit to have a minimum shape that can support the unit. Therefore, the resonance frequency f can be increased and high-speed scanning can be performed. At this time, if the shape of the mirror support part is made asymmetric so that the center of gravity of the scan part deviates from the center axis of the elastically deformable part, the eccentric load necessary for twisting and deforming is not necessary, and the number of parts can be reduced, resulting in cost reduction. Can be down.

Further, in the above optical scanner, since the thickness T of the elastically deforming portion and the width W thereof are set to W ≧ T, the vibrator rotates about an axis parallel to the vibration direction. It becomes difficult, and unnecessary vibration modes other than the necessary scanning direction can be reduced. Further, the vibrator can be made by a method such as etching, electric discharge machining, and press working. However, whichever method is used, W ≧ T has better manufacturing accuracy than W <T. An oscillator with stable characteristics can be realized.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an optical scanner 1 according to an embodiment of the present invention.
Indicates. The optical scanner 1 is composed of a vibrator 2 and a small drive source 6 such as a piezoelectric element or a magnetostrictive vibrator that generates a minute vibration. The oscillator 2 is provided with a vibration input section 4 at one end of a torsion bar-shaped elastically deformable section 3 having a bending deformation mode and a torsional deformation mode, and a mirror support section 8 supported by the elastically deformable section 3 at the other end and a light source. A scanning unit 5 including a mirror 7 for reflecting the light beam is provided. That is, the oscillator 2 is such that the mirror 7 is provided on the thin plate-shaped plate 9 in which the elastically deformable portion 3, the vibration input portion 4, and the mirror support portion 8 are integrally formed. The mirror 7 can be formed, for example, by subjecting a silicon wafer to mirror surface processing. By forming the mirror 7 from a silicon wafer or the like, the moment of inertia is reduced and high-speed scanning can be realized.

2 (a) and 2 (b) respectively show the plate 9
FIGS. 2A and 2B are a left side view and a plan view, and the plate 9 is made of a material having a small damping coefficient, such as a copper alloy, an aluminum alloy, or a titanium alloy, into a thin plate shape by pressing or the like. It can also be created by etching or electric discharge machining. Especially beryllium copper alloy and stainless steel SUS63
It is desirable to prepare the sample from No. 1, and it is preferable to use, for example, a mill-hardened material or a tension-annealed material that does not require age hardening treatment. At least the thickness T of the elastically deformable portion 3 of the plate 9 is made equal to or smaller than the width W of the elastically deformable portion 3 (that is, W ≧ T). The length L of the elastically deformable portion 3 is equal to the length L.
The ratio L / T between the thickness and the thickness T is approximately 100 ≧ L / T ≧ 5
It is created to be 0. Furthermore, the elastic deformation part 3
Has the same width W as the thickness T or is greater than or equal to the thickness T (W ≧
T).

In order to reduce the moment of inertia of the scan section 5, the mirror support section 8 is formed in a minimum shape so that the mirror 7 can be supported, and the center of gravity of the scan section 5 is away from the axis P of the oscillator 2. In order to be disengaged, the shape is asymmetric with respect to the axis P, for example, it is formed in a substantially inverted L shape as shown in FIG. Thereby, the inertia moment generating blade 56 and the weight 59 for generating the inertia moment, which are formed in the conventional optical scanner 51, can be eliminated. In addition, the connection portion 1 between the mirror support portion 8 and the elastic deformation portion 3
A substantially arc-shaped corner 10a is formed at the inner corner of 0, and the ratio R of the width W of the elastically deformable portion 3 to the radius R of the formed corner 10a is R.
/ W is created so that 1 <R / W <2.

The vibration input portion 4 is formed so that the connecting portion 11 between the elastic deformation portion 3 and the vibration input portion 4 is located near the center of the surface of the driving source 6, and the vibration from the driving source 6 vibrates. The input portion 4 is formed in a concave shape so that it can be efficiently input. Further, a substantially arc-shaped corner 11a is also formed in the inner corner of the connecting portion 11 between the vibration input portion 4 and the other end of the elastic deformation portion 3,
The radius R of the formed corner 11a and the width W of the elastically deformable portion 3
The ratio R / W is set to 1 <R / W <2.

When a vibration having a frequency equal to the resonance frequency f _B of the bending deformation mode of the elastic deformation portion 3 and / or the resonance frequency f _T of the torsion deformation mode of the elastic deformation portion 3 is applied to the vibration input portion 4 by the drive source 6, the elastic deformation is caused. The portion 3 vibrates in the elastic deformation mode and rotates the scanning portion 5 in the bending direction (θ _B direction) and / or the twisting direction (θ _T direction). At this time, when the mirror 7 of the scanning unit 5 is irradiated with the light beam, the reflected light beam has a rotation angle of 2 of the scanning unit 5.
The scanning angle is doubled.

In such a vibrator 2, since the thickness T of the elastically deformable portion 3 is made to have a relationship of T≤W with respect to the width W thereof, it is parallel to the vibration direction. Around the axis (Z
It becomes difficult to rotate around the axis, and the required scanning direction (θ _B
Direction and the θ _T direction), unnecessary vibration modes can be reduced. If the relation of T ≦ W is satisfied, the plate 9 is formed by etching, electric discharge machining or press working.
When producing the, the processing accuracy can be made higher than the relation of T> W, and the vibrator 2 having stable characteristics can be produced.

Further, since the relationship between the length L and the thickness T of the elastically deformable portion 3 is formed so as to be approximately 100 ≧ L / T ≧ 50, the length L of the elastically deformable portion 3 is shortened. As a result, the vibrator 2 can be downsized, and high-speed scanning becomes possible by increasing the resonance frequencies f _B and f _T. Further, since the stress amplitude Sa becomes smaller, the life can be extended. That is, since the length L and the thickness T of the elastically deformable portion 3 are related to the stress amplitude Sa of the vibrator 2 as can be seen from the equation, it is preferable to increase L / T from this point. / T ≧ 50 is good. On the other hand, since it is related to the resonance frequencies f _B and f _T of the vibrator 2 as can be seen from the formula and the formula,
From this point, the length L is short and the thickness T is large, so that L /
It is preferable to make T smaller, and it is preferable that 100 ≧ L / T. Therefore, the relationship between the length L and the thickness T is approximately 10
By making it fall within the range of 0 ≧ L / T ≧ 50, it is possible to create the vibrator 2 that is downsized, has a long life, and is capable of high-speed scanning.

Further, since the connecting portion 11 between the vibration input portion 4 and the elastically deforming portion 3 is formed so as to be positioned substantially in the center of the drive source 6, the vibrator 2 having the elastically deforming portion 3 having the same length. Compared with, the total length of the vibrator 2 can be shortened, and the optical scanner 1 can be downsized.

Further, the connecting portions 10 and 11 connecting the elastic deformation portion 3 and the mirror support portion 8 or the elastic deformation portion 3 and the vibration input portion 4 are also provided.
Since substantially circular arc-shaped corners 10a and 11a are provided at the inner corners, and the relationship R / W between the width W of the elastically deformable portion 3 and the radii R of the respective corners 10a and 11a is 1 <R / W <2. The concentrated stress generated in each of the corners 10a and 11a is relaxed, and damage to the vibrator 2 (plate 9) can be reduced. That is, the oscillator 2 is bent in the bending direction (θ _B
Direction), the maximum stress is generated in the connection portion 11 between the elastic deformation portion 3 and the vibration input portion 4. In addition, when the vibrator 2 is deformed in the twisting direction (θ _T direction), the maximum is obtained in the connection part 11 between the elastic deformation part 3 and the vibration input part 4 and the connection part 10 between the elastic deformation part 3 and the mirror support part 8. Stress is generated. Therefore, the concentrated stress is relieved by providing the substantially arc-shaped corners 10a and 11a in the connecting portions 10 and 11, and it is preferable to form the corners 10a and 11a so that 1 <R / W <2 at this time. Most preferred.

FIG. 3 is a diagram showing the relationship between the strength (tensile strength) of the metal material and the damping coefficient (cited from the Metal Material Handbook). The damping coefficient is the non-damping capacity (SDC: specific d) obtained by the torsional vibration method using 0.2% proof stress of a metal material as σy and using the maximum surface shear stress amplitude of σy / 10.
amping capacity), non-damping capacity SDC = (ΔW /
W) × 100 (%). However, W is elastic energy, and ΔW is energy loss per cycle. The smaller this damping coefficient is, the less likely the vibration is to be damped. Therefore, copper alloys such as bronze (○ in the figure) and brass (○ 2 in the figure), aluminum alloys (○ 3 in the figure), titanium alloys (○ 4 in the figure), etc. have a small damping coefficient. That is, by forming the plate 9 with these materials having a small damping coefficient, a large scanning angle can be obtained by a small vibration, and the driving source 6 can be driven with a low voltage.

FIG. 4 shows a comparison result of measuring the vibration amount-scanning angle characteristic of the driving source 6 in the optical scanner 1 using silicon and beryllium copper alloy as the material of the plate 9. The vertical axis represents the scanning angle (degree) of the optical scanner 1, and the horizontal axis represents the displacement amount (μm) of the drive source 6 as the vibration amount. Also, in FIG. 4, the solid line is the twist direction (θ _T direction).
, The broken line shows the scanning angle in the bending direction (θ _B direction), the black circles were measured with an optical scanner using beryllium copper alloy, and the white circles were measured with an optical scanner using silicon. Is represented. As can be seen from FIG. 4, when the plate 9 is made of beryllium copper alloy, the bending direction (θ _B direction)
As compared with the case where silicon is used in both the twisting direction (θ _T direction), a large scanning angle can be obtained with a small displacement amount of the driving source 6.

Next, FIG. 5 shows respective SN curves of two copper alloys, that is, a beryllium copper alloy and a phosphor bronze alloy. As can be seen from FIG. 5, when the same maximum surface stress is applied, the beryllium copper alloy (line a) can withstand more cycles than the phosphor bronze alloy (line b), and the fatigue strength can be improved. Is big. Therefore, if the vibrator 2 (plate 9) is made of beryllium copper alloy, the optical scanner 1 having a longer life can be made. Further, the stainless steel SUS631 also has a large fatigue strength similarly to the beryllium copper alloy.
The life of the optical scanner 1 can be extended by forming the plate 9 by using 1.

Further, since the plate 9 does not need to be bent, beryllium copper alloy or stainless steel SUS63 is used.
Among them, it is possible to use a material that has been subjected to age hardening treatment in advance to increase its strength, such as a mill-hardened material or a tension-annealed material. Therefore, by using the material that has been subjected to such age-hardening treatment, it is not necessary to perform heat treatment after processing the plate 9, and deformation such as warpage due to heat treatment does not occur. For this reason,
The plate 9 can be formed with high accuracy, and the optical scanner 1 with less variation can be provided.

[0043]

According to the first optical scanner of the present invention,
By setting the ratio L / T between the thickness T and the length L of the elastically deformable portion within a certain range, it is possible to provide an optical scanner that is small in size, has a long life, and can perform high-speed scanning.

Further, in the second optical scanner, the width W of the elastically deformable portion and the radius R of the substantially arc-shaped corner formed at the inner corner of the vibration input portion or the scanning portion at both ends of the elastically deformable portion are set. By setting the ratio R / W of R to within a certain range, the concentrated stress can be relaxed and the life of the optical scanner can be extended.

In the third optical scanner, the position of the end portion of the elastically deformable portion on the side of the vibration input portion is located substantially at the center of the surface of the vibration source, so that the length of the elastically deformable portion is not changed. Therefore, the size of the optical scanner can be reduced.

In the fourth optical scanner, at least the elastically deformable portion is made of a metal material having a small attenuation coefficient, so that the optical scanner is resistant to impact such as dropping and is small in size and power is saved. be able to. In particular, it is desirable to use beryllium copper alloy and SUS631.
At this time, if it is made of a material that does not require age hardening treatment, it is possible to provide an optical scanner with less variation.

In the fifth optical scanner, the scanning section is composed of the mirror section and the mirror supporting section which is connected to one end of the elastically deforming section and is smaller than the mirror section, thereby reducing the moment of inertia of the scanning section. Thus, high speed scanning can be enabled. At this time, if the mirror support is formed so that the center of gravity of the scanning unit deviates from the central axis of the optical scanner, a weight or the like for generating the moment of inertia becomes unnecessary, and the number of parts and cost can be reduced. You can

In the above optical scanner, by setting the width W of the elastically deformable portion to be equal to or larger than the thickness T of the elastically deformable portion, unnecessary vibration of the elastic deformation mode can be reduced, and the processing accuracy can be improved. A good optical scanner can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing an optical scanner which is an embodiment of the present invention.

2A and 2B are a left side view and a plan view, respectively, showing a plate of the above optical scanner.

FIG. 3 is a diagram showing a relationship between tensile strength and damping coefficient of a metal material.

FIG. 4 is a diagram showing a relationship between a displacement amount of a driving source and a scanning angle in the above optical scanner.

FIG. 5 is a diagram showing SN curves of a beryllium copper alloy and a phosphor bronze alloy.

FIG. 6 is a perspective view showing a conventional optical scanner.

FIG. 7 is a perspective view showing another conventional optical scanner.

8A and 8B are explanatory diagrams of an SN curve.

[Explanation of symbols]

 2 oscillator 3 elastically deforming portion 8 mirror supporting portion 10 connecting portion between elastically deforming portion and mirror supporting portion 11 connecting portion between elastically deforming portion and vibration input portion

Front page continuation (72) Inventor Atsushi Irie 10 Odoron-cho, Hanazono-cho, Ukyo-ku, Kyoto-shi, Omron Co., Ltd. (72) Inoue Masahiro Yoneda 10-yo Hanazono-do, Ukyo-ku, Kyoto-shi, Kyoto Omron Co., Ltd. (72) Inventor Kiyotoshi Okura 10 Odoron-cho, Hanazono-Tudocho, Ukyo-ku, Kyoto Prefecture (72) Inventor Norimasa Yamanaka 10 Ozoron-cho, Hanazono-Tudocho, Ukyo-ku, Kyoto (72) Invention Satoshi Ikeda 10 Odoron-cho, Hanazono, Ukyo-ku, Kyoto City, Kyoto Prefecture Omron Corporation

Claims (10)

[Claims] 1. An elastic deformation part having at least one elastic deformation mode, and a vibration input part provided at one end of the elastic deformation part for transmitting applied vibration to the elastic deformation part.
An optical scanner including a scan unit provided at the other end of the vibration input unit and rotating in accordance with an elastic deformation mode of the elastic deformation unit, and a vibration source that applies vibration to the vibration input unit, An optical scanner characterized in that a ratio L / T of the thickness T of the elastically deformable portion and the length L of the elastically deformable portion is approximately 100 ≧ L / T ≧ 50. 2. An elastic deformation part having at least one elastic deformation mode, and a vibration input part provided at one end of the elastic deformation part for transmitting applied vibration to the elastic deformation part.
An optical scanner including a scan unit provided at the other end of the vibration input unit and rotating in accordance with an elastic deformation mode of the elastic deformation unit, and a vibration source that applies vibration to the vibration input unit, A substantially arc-shaped corner is formed at an inner corner between the elastically deforming portion and the vibration input portion or at an inner corner between the elastically deforming portion and the scanning portion, and the width W of the elastically deforming portion and the corner are formed. An optical scanner having a ratio R / W of radii R of 1 <R / W <2. 3. An elastic deformation part having at least one elastic deformation mode, and a vibration input part provided at one end of the elastic deformation part and transmitting applied vibration to the elastic deformation part.
An optical scanner including a scan unit provided at the other end of the vibration input unit and rotating in accordance with an elastic deformation mode of the elastic deformation unit, and a vibration source that applies vibration to the vibration input unit, An optical scanner, wherein an end portion of the elastically deformable portion on the side of the vibration input portion is located at the center of the surface of the vibration source. 4. An elastic deformation part having at least one elastic deformation mode, and a vibration input part provided at one end of the elastic deformation part for transmitting applied vibration to the elastic deformation part.
An optical scanner including a scan unit which is provided at the other end of the vibration input unit and rotates according to an elastic deformation mode of the elastic deformation unit, and an excitation source which applies vibration to the vibration input unit, An optical scanner characterized in that the elastically deformable portion is made of a metal material having a small attenuation coefficient, such as a copper alloy, an aluminum alloy, or a titanium alloy. 5. The optical scanner according to claim 4, wherein the metal material is a beryllium copper alloy. 6. The metal material is stainless steel SUS63.
The optical scanner according to claim 4, wherein the optical scanner is 1. 7. The optical scanner according to claim 4, wherein the metal material is a metal material that does not require age hardening after processing. 8. An elastic deformation part having at least one elastic deformation mode, and a vibration input part provided at one end of the elastic deformation part and transmitting applied vibration to the elastic deformation part.
An optical scanner including a scan unit provided at the other end of the vibration input unit and rotating in accordance with an elastic deformation mode of the elastic deformation unit, and a vibration source that applies vibration to the vibration input unit, An optical scanner characterized in that the scanning section is composed of a mirror section for reflecting a light beam and a mirror supporting section having an area smaller than the area of the mirror section, and the mirror supporting section is provided at one end of the elastically deforming section. . 9. The shape of the mirror support portion is asymmetric with respect to the central axis of the elastic deformation portion so that the center of gravity of the scanning portion deviates from the central axis of the elastic deformation portion. Optical scanner. 10. The method according to claim 1, 2, 3, 4, 5, 6, 7,
8. The optical scanner according to 8 or 9, wherein the relationship between the thickness T of the elastically deformable portion and the width W of the elastically deformable portion is W ≧ T.