JPS6279413A - Deflecting device for multiple reflection type light - Google Patents

Abstract

PURPOSE:To perform large-angle deflection at a high speed by mounting plural reflecting mirrors which generate a standing wave with an electric signal on a piezoelectric element and fitting an internal reflecting mirror to a lid having a hole through which incident and projected light are passed, and thus constituting a multiple reflection system. CONSTITUTION:The piezoelectric element 3 is mounted on an electrode 1 formed on a substrate 2 and an electrode 4 is formed on the element 3. Reflecting mirrors 5 and 6 are fixed on the electrode 4 in a one-terminal free state. The reflecting mirrors 5 and 6 themselves vibrate to generate a standing wave. The internal reflecting mirror 10 sends reflected light deflected with the standing wave of the reflecting mirror 5 to the reflecting mirror 6 and a held on the lid 9. Then, a hole 7 where incident light 11 passes and a hole 8 where projected light 12 passes are bored in the lid 9. The light deflected with the standing wave generated by the reflecting mirror 5 through the vibration of the piezoelectric element 3 excited by an AC power source 15 becomes reflected light 13, which is reflected by the reflecting mirror 10 to generate reflected light 14. The reflected mirror 14 is deflected with a standing wave generated by the reflected mirror 6 and outputted as projected light 12. Thus, large-angle deflection is performed at a high speed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a light modification device, and in particular, to a device for modifying light, in which a piezoelectric element is expanded and contracted by applying an electric signal from the outside, and a reflecting mirror is vibrated by the expansion and contraction. The present invention relates to a multi-reflection light deflection device that can control both the direction of light and the period of its vibration by generating a standing wave on a reflecting mirror.

In addition, the deflection angle of the light can be controlled by which part of the reflector the light is reflected on, and furthermore, by controlling the voltage, it is possible to deflect the light in a frequency band of several hundred KHz. The present invention relates to a light deflection device that can obtain a large deflection angle by reflecting light.

[Prior Art] Conventionally, inventions related to light deflection and devices have been created by woodworkers.

For example, there are those that employ a rotating reflector system, those that use a tuning fork, and those that utilize standing waves.

The rotating reflector method is described in P3 of "Optical Technology" published by Kyoritsu Shuppan.
As described in No. 78, the light is deflected by mechanically rotating a reflecting mirror, and the structure is simple and a large deflection angle can be obtained. However, since the driving method is mechanical, there are problems with durability and reliability, and the direction change frequency can only be a few kHzL at most.

A device using a tuning fork is disclosed in Japanese Patent Application Laid-Open No. 52-11714 (Vibrating device using a tuning fork), in which a reflecting mirror is attached to the tip of the tuning fork, and the tuning fork is caused to resonate by an electromagnet. This vibration of the tuning fork causes the tip to
The incident angle of the attached reflecting mirror changes over time with respect to the optical axis, and the direction of the light is changed. Since this method uses a tuning fork, it is more durable and reliable than the rotating reflector method.

In addition, it is possible to deflect light at a higher speed (several hundred to several kilohertz) and the deflection angle can be large, so it is applied to various devices. However, this method also has the problem that it is physically and structurally difficult to make the tuning fork itself with high vibration in order to deflect the light at even higher speeds (several tens of KHz or more).

The device using standing waves is disclosed in Japanese Patent Application No. 59-274148 (Light deflection device using standing waves K), which is filed by the same applicant as the present application.
), a single reflecting mirror is mounted on a piezoelectric element in a cantilevered state, and a standing wave is generated on the reflecting mirror by applying an external electrical signal. Then, the standing wave generated on the surface of the reflecting mirror is modulated once to change the direction of the light and control it. This method has much better durability and reliability than those using a rotating reflector method or a tuning fork, and also has the feature of being able to change the direction of light at high speed (several hundred KHz). However, when the deflection angle is 30 crn away, it is as small as several tens of μm.

[Problems to be Solved by the Invention] As described above, in the conventional light deflection device, the rotating reflector type has a simple structure and a large deflection angle can be obtained, but the mechanical drive type does not. Therefore, it lacks durability and reliability,
Furthermore, there was a drawback that the redirection frequency of the light was also low.

In the case of a light deflection device using a tuning fork, compared to a rotating reflector system, it is superior in terms of reliability and durability because it utilizes the inherent physical properties of a tuning fork. However, although the redirection frequency of light is quite fast, ranging from several hundred Hz to several KHz,
If even faster sampling is required, faster light redirection is required, which is not possible with this light redirection device.

A light deflection device that makes full use of standing waves is far superior to the above two devices in terms of durability and reliability. On top of that, the pressure is 1! Since the element was used as the vibration source of the reflecting mirror, it was possible to change the direction of light at a much higher speed (several hundred KHz) compared to the above-mentioned light turning device (tuning fork, rotating reflector, etc.). However, since the deflection angle is small, it is inferior to the above-mentioned original deflection device, and there is a problem in that its use is severely restricted.

[Means to Solve the Problems] The present invention takes the following measures to overcome this situation. That is, (1) by applying an external electrical signal to the piezoelectric element, the piezoelectric element itself repeats expansion and contraction in response to the electric signal, and (2) the expansion and contraction is caused by mechanical vibration due to its structure. (3) The plurality of reflection mirrors are supported on all sides, that is, cantilevered, and the piezoelectric element expands and contracts at high speed (several hundred KHy, ) to generate a standing wave under certain conditions, and (4) install multiple internal reflections on the opposite side of the reflector as necessary to cause this standing wave to cause multiple reflection deflections. I made sure to have a mirror.

Since this invention has a multiple reflection system configuration as described above, it can be deflected many times by the standing wave, and in order to change the direction by the standing wave, nine elements can be deflected by an external signal. The deflection direction and deflection angle can be controlled, and furthermore, by making the electric signal received from the outside a high frequency, high frequency vibration is also possible. At the same time, by increasing the optical path length to perform multiple reflections, we were able to increase the deflection angle.

Therefore, the present invention provides a multi-reflection type light changer that can change the direction of light at a high speed that could not be achieved with conventional light changers, and can obtain a large deflection angle when changing the direction. Among the optical deflection devices, an example is a twice-reflection optical deflection device (ODM) that applies modulation twice.

J Embodiment] FIG. 1 is a structural diagram showing an embodiment of a double-reflection type original direction changing device among the embodiments of the present invention. FIG. 2 is an operational diagram of the light deflection device, in which parts having the same functions as those in FIG. 1 are given the same reference numerals.

In the figure, 2 represents a substrate on which the first electrode 1 can be formed, 3 represents a piezoelectric element placed on the first electrode 1, and 4 represents a piezoelectric element placed on the top surface of the piezoelectric element 3. A second electrode is paired with 1 for applying an electric signal to the piezoelectric element, and 5 and 6 represent a reflecting mirror fixed on the second electrode 4 with one free end.

Since the reflecting mirrors 5 and 6 themselves move and generate standing wave sound, they are made of a thin cover glass coated with aluminum vapor-deposited. 10 is an internal reflecting mirror for sending the first reflected light deflected by the standing wave of reflecting mirror 5 to reflecting mirror 6; 7 is a hole for passing incident light; 8 is for passing outgoing light; 9 is a hole for holding the internal reflecting mirror. 11 is incident light, 12 is outgoing light,
13 indicates the first reflected light, and 14 indicates the second reflected light. 15 is a power source for supplying voltage to the piezoelectric element; 16
1 and 2 respectively show the entire double-reflection type light deflection device. 1 indicates a first electrode on a substrate 2 on which an electrode can be formed.

This substrate 2 is made of conductive aluminum, copper, etc., or by gold plating or forming a metal thin film on the substrate.

When the piezoelectric element 3 excited by the AC power source 15 vibrates, the reflecting mirror 5 and the reflecting mirror 6 vibrate. However, reflector 5
Since the reflecting mirror 6 is supported on one side, that is, fixed in a cantilevered state, standing waves are generated in the reflecting mirror due to vibration.

[Function] Hereinafter, the operation of the twice-reflection type light deflection device, which is an embodiment of the present invention, will be explained using FIG. 2.

In the figure, the second electrode 4 on the top of the piezoelectric element 3 and the substrate 2
By applying an electrical signal between it and the upper first electrode 1, the piezoelectric element 3 itself repeats expansion and contraction in response to the electrical signal. Therefore, the vibration is transmitted to the reflecting mirror 5 and the reflecting mirror 6 fixed to the upper part of the piezoelectric element 3. The reflection fip, 5.6 is supported on one side, that is, cantilevered, and the piezoelectric element 3 expands and contracts at high speed (several hundred KHz).
), a standing wave is generated in the reflecting mirrors 5 and 6. At this time, it is necessary to select reflective mirrors 5 and 6 that have the same length and are made of the same material. This is to make it easier to obtain resonance points at the same frequency.

This standing wave is generated periodically and repeatedly as a function of time, creating the state shown in FIG.

Therefore, the angular direction of the reflecting surface of the reflecting mirror changes with respect to the incident light that enters from a certain direction. As a result, the angle of incidence changes over time, and the direction of light reflected by the mirror surface also changes. In the first reflection, the light that is deflected by the standing wave generated on the reflecting mirror 5 becomes the first reflected light 13, and is further reflected by the internal reflecting mirror 10 to become the second reflected light 14. .

This second reflected light], 4 is deflected by a standing wave generated in the reflecting mirror 6 and output as an output light 12.

In addition, this invention has the advantage of being able to take a long optical path by reciprocating the light within the reflector, and is also much faster (several hundred K
Hz) direction change is possible. Furthermore, in terms of reliability and durability, it has become possible to obtain a larger deflection angle than a light deflection device that uses a mechanically driven standing wave.

FIG. 3(,) shows the configuration of the above-described twice-reflection type light deflection device 16' (when applied to an I-angle sensor).

The light 33 emitted from the laser beam oscillator 14 kept horizontally enters the twice-reflection type original deflection device 16, and by applying an electric signal to the twice-reflection type original deflection device 16, the laser beam is changed. is diverted. The deflected light 34 enters the mirror surface piece along the object 16 whose entire angle is to be measured, is reflected again by the mirror surface 15, and is detected by the photodetector array 17. Since the angle at which the light enters the mirror surface 16, that is, the angle of incidence, varies rapidly over time and sampling is possible, the angle to be measured can be determined from the deflection angle of the light deflection device.

FIG. 3(b) td shows the configuration when the twice-reflection type light deflection device is used as an outer diameter measuring device.

The light 30 emitted from the laser beam oscillator 14 enters the double-reflection beam deflection device 16, and by applying an electric signal to the line beam deflection device, the V-za light is deflected at high speed. The deflected laser beam 32 hits the target object 11 and creates a shadow on the back surface. The photodetector array 13 detects the shadow. This allows high-speed sampling and accurate measurement of the outer diameter of the object in a short time.

[Effects of the Invention] As explained above, the basic technical idea of the present invention is that the number of reflecting mirrors (I-2 or more) mounted on the piezoelectric cable 3,
(Alternatively, the number of internal reflectors attached to the cover 9 is 1.
It has the advantage that it can be used in a wide range of optical applications, and can be used in both directions when necessary.

[Brief explanation of drawings]

FIG. 1 is a structural diagram showing an embodiment of a twice-reflection type light deflection device according to an embodiment of the present invention, and FIG. 2 is a diagram showing an operating state of the present invention. FIGS. 3(a) and 3(b) show configuration diagrams in which the twice-reflection type light deflection device is applied to an angle sensor and an outer diameter measuring device, respectively. In the figure, 1 is a first electrode, 2 is a substrate on which electrodes can be formed, and 3
4 is a piezoelectric element, 4 is a pressure FM, a second electrode on the element, 5 and 6 are reflecting mirrors, 7 is a hole for incident light, 8 is a hole for output light, 9 is a lid for holding the internal reflecting mirror, 10 is a Internal reflector, 15 is a power source. Patent applicant: Anritsu Corporation Representative, Ryutabe Koike, Patent attorney No. 1 Fig. 2 (a) (b) Fig. 3 6 Light redirection bag I At the desired angle Direction device for 6 mirror lights along

Claims (1)

[Claims] A substrate (2) having a first electrode (1) on its surface;
a piezoelectric element (3) placed on the electrode (1); provided on the upper surface of the piezoelectric element (3) and forming a pair with the first electrode (1); a second electrode (4) for applying an electric signal to the second electrode (4); one end placed on the second electrode (4) and the other end free to vibrate; A plurality of reflecting mirrors (5) and (6) that generate waves, a hole (7) for passing incident light to the reflecting mirror, and a hole (8) for passing light emitted from the reflecting mirror. ); attached to the back surface of the lid (9), the plurality of reflecting mirrors (
5) A multi-reflection type light deflection device comprising at least one internal reflection mirror (10) constituting a multi-reflection system together with (6).