JP2004117833A - Optical attenuator, electronic equipment, and method for driving optical attenuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical attenuator capable of attenuating light with less driving force, and also to provide related electronic equipment and a method for driving the optical attenuator. <P>SOLUTION: The optical attenuator includes, in the structure, a shield plate 10 for shielding projection light from a projector, a hinge 19 formed in a manner freely expanded and contracted for supporting the shield plate 10, and an electrode 11 which is formed so as to be able to generate Coulomb force and which sucks the shield plate 10 and the hinge 19 to drive them horizontally by generating the Coulomb force. With the electrode 11 adjusting the Coulomb force, the shielding quantity of light is adjusted. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical attenuator, an electronic device, and an optical attenuator driving method.
[0002]
[Background Art]
When driving an optical attenuator, it is an issue to drive the optical attenuator with less driving force.
[0003]
Conventionally, as described in Patent Document 1, for example, a filter or a shutter is driven to attenuate light. In the method described in Patent Document 1, the shielding plate is driven using a cam and a drive motor.
[0004]
As described above, conventionally, since the shielding plate or the like is driven by using the drive motor or the like, the amount of energy required for driving is large.
[0005]
Further, in order to perform more accurate attenuation, it is necessary to accurately control the driving of the shielding plate and the like.
[0006]
For example, in Patent Literature 1, in order to finely adjust the shielding amount of the shielding plate, as described in Paragraph No. 0050 of the specification of Patent Literature 1, the number of slits provided in the encoder held together with the cam is reduced. The rotation angle is measured by counting with an interrupter.
[0007]
[Patent Document 1]
JP-A-2002-131659
[Problems to be solved by the invention]
However, the method described in Patent Literature 1 has a problem in that the mechanism is complicated and a rotating mechanism is required, so that a driving force for rotation is required, and light is attenuated with less driving force. This is not an appropriate solution.
[0009]
SUMMARY An advantage of some aspects of the invention is to provide an optical attenuator, an electronic device, and an optical attenuator driving method capable of attenuating light with less driving force. In particular, an object of the present invention is to provide an optical attenuator, an electronic device, and an optical attenuator driving method capable of more accurately attenuating light with less driving force.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, an optical attenuator according to the present invention includes a shielding member that shields projection light from a light projection unit,
A support member formed to be extendable and contractable to support the shielding member,
A suction unit that is formed so as to be capable of generating Coulomb force, and suctions the shielding member and the support member by generating Coulomb force;
Including
The suction unit may adjust a Coulomb force to adjust a light shielding amount.
[0011]
According to another aspect of the invention, there is provided an electronic apparatus including the optical attenuator.
[0012]
Further, the light attenuator driving method according to the present invention, a shielding member for shielding the projection light from the light projection unit,
A suction unit formed to generate Coulomb force and suctioning the shielding member by generating Coulomb force;
An optical attenuator driving method for driving an optical attenuator including:
By increasing the Coulomb force or decreasing the Coulomb force, the shielding member is driven to adjust the amount of light shielding.
[0013]
According to the present invention, a light attenuator or the like can attenuate light with a smaller driving force by driving a shielding member using Coulomb force (electrostatic force).
[0014]
In the optical attenuator, the electronic device, and the optical attenuator driving method, the shielding member may include a plurality of openings in a portion where the projection light is projected such that a shielding amount varies depending on a position of the shielding member. May be provided.
[0015]
According to this, the optical attenuator and the like have a plurality of openings in the shielding member, so that even when the amount of movement of the shielding member is small as compared with the case where the opening is not provided in the shielding member, the light attenuator is larger. The amount of shielding can be adjusted.
[0016]
The light attenuator and the electronic device, a light receiving unit that receives the reflected light of the projection light from the shielding member,
A control unit that controls the suction unit to adjust the Coulomb force based on the amount of light received by the light receiving unit,
May be included.
[0017]
Further, in the optical attenuator driving method, the reflected light of the projection light from the shielding member is received,
The Coulomb force may be adjusted based on the amount of received light.
[0018]
According to this, the optical attenuator or the like can recognize the amount of light attenuation by receiving the reflected light of the shielding member and adjusting the Coulomb force. Therefore, the optical attenuator or the like can more accurately attenuate the light by performing feedback control of the Coulomb force.
[0019]
In the optical attenuator and the electronic device, the shielding member is formed such that a reflection portion that reflects the projection light is inclined with respect to an optical axis of the projection light,
The light receiving unit may be provided at a position different from the light projection unit.
[0020]
According to this, since the optical attenuator can receive light at a position different from the light projection position, there is no need to adjust the amount of light attenuation while switching between light projection and light reception. Can be attenuated.
[0021]
Further, in the optical attenuator and the electronic device, the distance between the suction unit and the support member may be increased as the distance from the shielding member increases.
[0022]
According to this, since the optical attenuator and the like can gradually suck the suction member from the portion of the support member located at a position distant from the shielding member, it is possible to drive the shielding plate more with less driving force. it can.
[0023]
That is, if the distance between the suction part and the support member is large, a larger suction force is required, but since the distance between the part of the support member at a position away from the shielding member and the suction part is small, the optical attenuator and the like By driving the supporting member with a small driving force, and by sucking the portion, it is possible to bring a portion of another supporting member closer to the suction portion side, so that the supporting member can be driven with a smaller driving force.
[0024]
In addition, since the space between the shielding member and the support member at a position close to the shielding member and the suction unit can be widened, a sufficient space for moving the shielding member can be secured. The member can be largely driven.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a case where the present invention is applied to an optical attenuator (also referred to as an attenuator) will be described as an example with reference to the drawings. The embodiments described below do not limit the contents of the invention described in the claims. In addition, all of the configurations described in the following embodiments are not necessarily indispensable as means for solving the invention described in the claims.
[0026]
(Example)
FIG. 1 is a plan view showing a state of the optical attenuator according to an example of the present embodiment when it is not driven. FIG. 2 is a plan view showing a state of the optical attenuator at the time of driving according to an example of the present embodiment. FIG. 3 is a schematic diagram of a cross section of an optical attenuator according to an example of the present embodiment.
[0027]
The light attenuator according to the present embodiment includes a light projection unit 31, a shielding plate 10 that is a shielding member that shields projection light from the light projection unit 31, and a support member that is formed to extend and contract to support the shielding plate 10. It is configured to include a certain hinge 19 and an electrode 11 that is formed so as to generate a Coulomb force and functions as a suction unit that suctions the shield plate 10 and the hinge 19 by generating the Coulomb force.
[0028]
The optical attenuator is configured to include an electrode 12 provided on the opposite side of the electrode 11 via the shielding plate 10, and an electrode 13 provided between the electrode 11 and the electrode 12 and supporting the hinge 19. ing.
[0029]
Further, the light attenuator controls the voltage applied to the electrode 11 to adjust the Coulomb force based on the amount of light received by the light receiving unit 32 and the amount of light received by the light receiving unit 32, the light receiving unit 32 receiving the reflected light of the projection light of the shielding plate 10. And a control unit 33 that controls the projection of the light projection unit 31.
[0030]
The shielding plate 10, the electrodes 11 to 13, and the hinge 19 are integrally formed as the silicon substrate 1. Further, the silicon substrate 1 is supported by the glass substrate 2, and a light shielding portion 21 having a circular opening is provided on the glass substrate 2. Further, the light projecting unit 31 and the light receiving unit 32 are provided outside the glass substrate 2, and project and receive light through the glass substrate 2.
[0031]
Further, as shown in FIG. 3, in the shielding plate 10, a reflection portion that generates reflected light is formed to be inclined with respect to the optical axis of the light projected from the light projection unit 31. Further, the light receiving unit 32 is provided at a position different from the light projecting unit 31 so that the reflected light can be received.
[0032]
In addition, as a material for realizing such an optical attenuator, for example, the following materials can be applied.
[0033]
For example, the silicon substrate 1 is made of, for example, silicon doped with boron atoms to impart conductivity, and the glass substrate 2 is made of, for example, sodium borosilicate glass, and the shielding plate 10 and the hinge 19 are used. For example, the same material as the silicon substrate 1 or another material may be used.
[0034]
Further, as the electrodes 11 to 13, for example, a transparent electrode such as ITO may be used. Further, for example, chromium, gold, or the like may be used as the light shielding unit 21.
[0035]
The light projection unit 31 can be realized using, for example, a laser diode, an LED (light emitting diode), or the like, and may convert light from the laser diode or the like into parallel light using a collimating lens or a diffraction grating. As the light receiving unit 32, for example, a photodiode or the like may be used, and as the control unit 33, for example, a control circuit or the like may be used.
[0036]
Further, as shown in FIG. 1, since the hinge 19 is made of silicon, it is formed to be elongated so as to have elasticity. As a result, the hinge 19 expands when attracted to the electrode 11 side, and contracts when separated from the electrode 11 side, so that the shielding plate 10 can be driven in the horizontal direction.
[0037]
Further, when further elasticity is required, as shown in FIG. 7, the elasticity can be improved by processing the hinge 119 into a bellows shape.
[0038]
Further, as shown in FIG. 1, the distance between the hinge 19 and the electrode 11 is narrow on the electrode 13 side and wide on the shielding plate 10 side. By adopting such a configuration, the hinge 19 can be gradually attracted to the electrode 11 from the electrode 13 side toward the shield plate 10 side, and a sufficient space for moving the shield plate 10 is secured. be able to.
[0039]
In particular, since the Coulomb force has a distance dependency that becomes stronger as the interval becomes smaller, the optical attenuator can drive the shielding plate 10 more with less driving force by employing such a configuration. Further, by adopting such a configuration, as shown in FIG. 2, the degree of bending of the hinge 19 can be small even during driving, so that the durability of the hinge 19 can be increased.
[0040]
The method of manufacturing the optical attenuator of the present embodiment can be realized by using a general micromachining technique, and for example, a method described in Japanese Patent Application Laid-Open No. 9-159937 may be used. In particular, by using the micromachining technology, the optical attenuator can be easily reduced in size.
[0041]
Next, the operation principle of the optical attenuator of the present embodiment will be described.
[0042]
FIG. 4 is a flowchart illustrating an operation of the optical attenuator according to an example of the present embodiment.
[0043]
First, the control unit 33 drives the light projection unit 31 to project light, and generates a drive signal for driving the electrode 11 (step S1).
[0044]
The electrode 11 applies a voltage of 5 V based on the control signal (Step S2).
[0045]
The electrodes 12, 13, the shielding plate 10, and the hinge 19 are at 0V. When the voltage of the electrode 11 becomes 5 V, a potential difference of 5 V is generated between the shield plate 10 and the hinge 19, and a Coulomb force is generated. Thereby, the shielding plate 10 and the hinge 19 are driven substantially horizontally so as to be attracted to the electrode 11 side (step S3).
[0046]
As a result, the optical attenuator changes from a completely shielded state as shown in FIG. 1 to a state in which part or all of the projection light is projected to the outside as shown in FIG.
[0047]
The light receiving unit 32 receives the reflected light from the shielding plate 10 (Step S4).
[0048]
As shown in FIG. 3, the light receiving amount of the light receiving unit 32 increases as the ratio of being blocked by the shielding plate 10 increases, and the light receiving amount of the light receiving unit 32 decreases as the ratio of being blocked by the shielding plate 10 decreases.
[0049]
The control unit 33 determines whether or not the driving state of the shielding plate 10 is appropriate, based on the received light amount, in a preset shielding state (step S5).
[0050]
If the control unit 33 determines that the driving amount of the shielding plate 10 is not appropriate, the control unit 33 adjusts the driving force by the electrode 11 (Step S6). Specifically, the control unit 33 adjusts the driving force by, for example, changing the drive signal performed in the process of step S1 to change the applied voltage.
[0051]
When the driving amount of the shielding plate 10 is appropriate, the control unit 33 determines whether or not to end the process (Step S7). Continues the processing of steps S1 to S7.
[0052]
As described above, according to the present embodiment, the optical attenuator drives the shielding plate 10 almost horizontally using Coulomb force, so that it is not necessary to use a rotary drive mechanism or the like, and thus the optical attenuator requires less driving force. The light attenuation can be adjusted at high speed.
[0053]
Further, since the light attenuator of the present embodiment drives the shielding plate in the horizontal direction to attenuate the light, the light can be attenuated in an analog manner.
[0054]
In this embodiment, a plurality of optical attenuators can be arranged in an array, so that high integration is easy.
[0055]
Further, since the optical attenuator electrostatically drives the mirror 10 and the like using Coulomb force, power consumption and heat generation can be reduced.
[0056]
Further, according to the present embodiment, the light attenuator can grasp the amount of light attenuation by receiving the reflected light of the shielding plate 10. For this reason, the optical attenuator can more accurately attenuate the light by performing feedback control of the Coulomb force according to the amount of reflected light received.
[0057]
Furthermore, according to the present embodiment, since the optical attenuator can receive light at a position different from the light projection position, there is no need to adjust the amount of light attenuation while switching between light projection and light reception, so that more efficiency is achieved. Light can be effectively attenuated.
[0058]
(Modification)
Further, the application of the present invention is not limited to the above-described embodiment, and various modifications are possible.
[0059]
For example, in the above-described embodiment, the shielding plate 10 has no opening, but the shielding plate 10 may have an opening.
[0060]
FIG. 5 is a plan view of the shielding plate 110 according to an example of the present embodiment.
[0061]
The shielding plate 110 has a plurality of openings 111 to 115 at a portion where the projection light is projected so that the shielding amount varies depending on the position of the shielding plate 110.
[0062]
According to this, in the optical attenuator, since the shielding plate 110 has the plurality of openings 111 to 115, the amount of movement of the shielding plate 110 is smaller than when the opening is not provided in the shielding plate 110. However, the amount of shielding can be adjusted to a greater extent.
[0063]
Further, as shown in FIG. 5, the shape of the opening may be a circular shape like the opening 111, a rectangular shape like the openings 112 to 115, and various shapes. Can be adopted.
[0064]
Further, the shielding plate may be made of a transparent material, and a light shielding portion may be provided in a part thereof.
[0065]
FIG. 6 is a cross-sectional view of a shielding plate 210 according to another example of the present embodiment.
[0066]
The shielding plate 210 is formed of a transparent material such as glass, and is formed in a trapezoidal shape having a smaller cross-sectional area upward, and light shielding portions 211 and 212 are formed on the oblique sides of the trapezoid.
[0067]
By adopting such a configuration, as shown in FIG. 6, light that has hit the light shielding units 211 and 212 does not pass through the shielding plate 210, and light that has not hit the light shielding units 211 and 212 passes through the shielding plate 210. Since the light is transmitted, the light attenuator can adjust the amount of light attenuation by driving the shielding plate 210 in the horizontal direction.
[0068]
Further, in the above-described embodiment, only the electrode 11 functions as the suction unit. However, by making both the electrode 11 and the electrode 12 function as the suction unit and selectively applying a voltage to the electrode 11 and the electrode 12, In FIG. 1, the optical attenuator may be configured to suck and drive the shielding plate 10 and the hinge 19 in both the left and right directions.
[0069]
Further, in the above-described embodiment, the light projecting unit 31 and the light receiving unit 32 are provided at different positions. However, an apparatus provided at the same position or having both functions of the light projecting unit 31 and the light receiving unit 32 may be applied. . Specifically, for example, an optical fiber may be provided at the position of the light projection unit 31, and light emission and light reception may be repeatedly performed.
[0070]
The voltage applied to the electrode 11 and the like is 0 V and 5 V in the above-described embodiment, but is not limited to these values.
[0071]
Further, in the above-described embodiment, the mirror is driven using the Coulomb force. However, for example, the mirror may be driven using an electromagnetic force.
[0072]
Further, the optical attenuator according to the present invention can be mounted on various electronic devices such as a router and a projector in addition to the optical switch.
[Brief description of the drawings]
FIG. 1 is a plan view showing a state of an optical attenuator at the time of non-driving according to an example of the present embodiment.
FIG. 2 is a plan view showing a state of an optical attenuator during driving according to an example of the embodiment.
FIG. 3 is a schematic diagram of a cross section of an optical attenuator according to an example of the present embodiment.
FIG. 4 is a flowchart illustrating an operation of the optical attenuator according to an example of the present embodiment.
FIG. 5 is a plan view of a shielding plate according to an example of the embodiment.
FIG. 6 is a cross-sectional view of a shielding plate according to another example of the present embodiment.
FIG. 7 is a plan view showing a state of an optical attenuator at the time of non-driving according to another example of the embodiment.
[Explanation of symbols]
Reference Signs List 1 silicon substrate, 2 glass substrate, 10, 210 shielding plate (shielding member), 11 electrode (suction unit), 12, 13 electrode, 19, 119 hinge (supporting member), 21, 211, 212 light shielding unit, 111 to 115 Aperture

Claims (9)

A shielding member for shielding the projection light from the light projection unit,
A support member formed to be extendable and contractable to support the shielding member,
A suction unit that is formed so as to be capable of generating Coulomb force, and suctions the shielding member and the support member by generating Coulomb force;
Including
The optical attenuator, wherein the suction unit adjusts a Coulomb force to adjust a light blocking amount. In claim 1,
The light attenuator, wherein the shielding member has a plurality of openings at a portion where the projection light is projected so that a shielding amount varies depending on a position of the shielding member. In any one of claims 1 and 2,
A light receiving unit that receives reflected light of the projection light from the shielding member,
A control unit that controls the suction unit to adjust the Coulomb force based on the amount of light received by the light receiving unit,
An optical attenuator comprising: In claim 3,
The shielding member is formed such that a reflection portion that reflects the projection light is inclined with respect to an optical axis of the projection light,
The light attenuator, wherein the light receiving unit is provided at a position different from the light projecting unit. In any one of claims 1 to 4,
An optical attenuator, wherein the distance between the suction part and the supporting member is formed wider as the distance from the shielding member becomes closer. An electronic device comprising the optical attenuator according to claim 1. A shielding member for shielding the projection light from the light projection unit,
A suction unit formed to generate Coulomb force and suctioning the shielding member by generating Coulomb force;
An optical attenuator driving method for driving an optical attenuator including:
A method for driving an optical attenuator, comprising: increasing the Coulomb force or weakening the Coulomb force to drive the shielding member to adjust a light shielding amount. In claim 7,
The method of driving an optical attenuator, wherein the shielding member has a plurality of openings at a portion where the projection light is projected so that a shielding amount varies depending on a position of the shielding member. In any one of claims 7 and 8,
Receiving reflected light of the projection light from the shielding member,
A method for driving an optical attenuator, comprising adjusting the Coulomb force based on the amount of received light.

Images