JP2020003451A - Scanner, scanner drive method, program, recording medium, and distance measuring device - Google Patents

Abstract

To provide a scanner and a distance measuring device with which it is possible to accurately and reliably receive reflected light from an object while downsizing a light receiving element and perform accurate scanning and distance measurement, method and program for driving these devices and a recording medium.SOLUTION: The scanner comprises: a light source 21 for emitting primary light; a first deflection element 22 for direction-variably deflecting the primary light and projecting the deflected primary light as scanning light; a second deflection element 31 for direction-variably deflecting secondary light derived from scanning light by reflection upon an object and operating following the first deflection element and lagging behind the first deflection element; and a light receiving element 32 for receiving the secondary light having gone through the second deflection element.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a scanning device that performs optical scanning and a ranging device that performs optical ranging, and a driving method, a program, and a recording medium that drive these devices.

  2. Description of the Related Art Conventionally, there has been known a distance measuring device that irradiates an object with light and detects light reflected by the object to optically measure a distance to the object. Further, there is known a scanning distance measuring device that performs optical scanning on a predetermined area and measures distances to various objects existing in the area. For example, Patent Literature 1 includes a light projecting unit that emits an irradiation light pulse to an object to be measured, and a light receiving unit that has a plurality of light receiving pixels that receive the reflected light pulse reflected by the object to be measured. An optical ranging device is disclosed.

JP 2016-176750 A

  The scanning distance measuring device includes, for example, a scanning device that scans a predetermined area by projecting a pulsed light toward a predetermined area while deflecting the light in a variable direction. Further, the scanning device includes a light receiving unit that receives the pulse light reflected by the object. In this case, the projection direction of the pulse light used for scanning changes. Accordingly, the direction of incidence of the reflected pulse light on the scanning device changes.

  Further, for example, when the distance measuring device is mounted on a moving object such as a vehicle, it is preferable that the range of distance that can be measured is wide. Therefore, it is preferable that the distance can be accurately measured even when the distance to the object is largely different. Therefore, it is necessary to consider that the time from when the pulsed light is emitted to when the pulsed light returns to the scanning device, that is, the timing at which the light receiving unit receives the reflected light from the object greatly differs depending on the position of the object. is there.

  Considering these, the scanning device tends to be provided with a light receiving element having a sufficiently large light receiving surface so that light incident from various directions at various timings can be received. However, when a light receiving element having a large light receiving surface is provided, it becomes easy to receive other light that becomes noise. Therefore, not only the device is increased in size, but also a complicated signal processing circuit must be provided.

  The present invention has been made in view of the above points, a scanning device capable of accurately and reliably receiving reflected light from a target object while reducing the size of a light receiving element, and capable of performing accurate scanning and distance measurement. It is an object to provide a distance measuring device, and a method, a program, and a recording medium for driving these devices.

  The invention according to claim 1 is a light source that emits primary light, and a first deflecting element that performs an operation of deflecting the primary light in a variable direction and projects the deflected primary light as scanning light. A second deflecting element that deflects the secondary light, the scanning light reflected by the object, in a variable direction to follow the first deflecting element and operate with a delay from the first deflecting element; And a light receiving element for receiving the secondary light having passed through the deflecting element.

  According to a tenth aspect of the present invention, there is provided the scanning device according to the first aspect, and a distance measuring unit that measures a distance to an object based on a result of receiving the secondary light by the light receiving element. It is characterized by.

  According to the eleventh aspect of the present invention, a first light source for emitting primary light and an operation of deflecting the primary light in a variable direction to project the deflected primary light as scanning light are provided. A deflecting element, a second deflecting element that performs an operation of variably deflecting the secondary light reflected from the object by the scanning light, and a light receiving element that receives the secondary light having passed through the second deflecting element. A method of driving a scanning device having the second deflecting element following the first deflecting element and operating with a delay from the first deflecting element.

  In a twelfth aspect of the present invention, the computer performs a light source for emitting primary light and an operation of deflecting the primary light in a variable direction, and emits the deflected primary light as scanning light. A scanning device including a first deflecting element, a second deflecting element that performs an operation of variably deflecting the secondary light reflected by the object with the scanning light, and a light receiving element that receives the secondary light is provided. The second deflecting element functions as a drive unit that drives the second deflecting element so as to follow the first deflecting element and operate with a delay from the first deflecting element.

  The invention according to claim 13 is characterized in that the program according to claim 12 is recorded.

FIG. 2 is a diagram illustrating a configuration example of a distance measuring apparatus according to the first embodiment. FIG. 3 is a top view of a first deflection element of the distance measuring apparatus according to the first embodiment. FIG. 3 is a top view of a second deflection element of the distance measuring apparatus according to the first embodiment. FIG. 4 is a diagram illustrating an operation example of first and second deflection elements of the distance measuring apparatus according to the first embodiment. FIG. 3 is a diagram illustrating an operation example of the distance measuring apparatus according to the first embodiment. FIG. 3 is a diagram illustrating an operation example of the distance measuring apparatus according to the first embodiment. FIG. 9 is a diagram illustrating an operation example of the distance measuring apparatus according to Comparative Example 1. FIG. 9 is a diagram illustrating an operation example of the distance measuring apparatus according to Comparative Example 1. FIG. 7 is a diagram illustrating a configuration example of a distance measuring apparatus according to a first modification of the first embodiment. FIG. 9 is a top view of a first deflection element of the distance measuring apparatus according to the first modification of the first embodiment. FIG. 9 is a top view of a second deflection element of the distance measuring apparatus according to the first modification of the first embodiment. FIG. 9 is a diagram illustrating an example of a position of light incident on a light receiving element in the distance measuring apparatus according to the first modification of the first embodiment. FIG. 9 is a diagram illustrating an example of a position of light incident on a light receiving element in the distance measuring apparatus according to Comparative Example 2. FIG. 9 is a diagram illustrating a configuration example of a distance measuring apparatus according to a second modification of the first embodiment. FIG. 7 is a diagram illustrating a configuration example of a distance measuring apparatus according to a second embodiment. FIG. 9 is a diagram illustrating a configuration example of a distance measuring apparatus according to a third embodiment.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a diagram illustrating a configuration example of a distance measuring apparatus 10 according to the first embodiment. The distance measuring device 10 is a scanning distance measuring device that performs optical scanning of a predetermined region (hereinafter, referred to as a scanning region) R0 and measures a distance to an object OB existing in the scanning region R0. First, the distance measuring device 10 includes a scanning device (scanning unit) 11.

  The scanning device 11 includes a light source 21 that emits light (hereinafter, referred to as primary light) L1 and a deflecting element (hereinafter, referred to as a first deflection) that deflects the primary light L2 and emits the scanning light L2 to the scanning region R0. (Hereinafter referred to as an element) 22.

  For example, in the present embodiment, the light source 21 has a laser element that generates and emits a laser beam as the primary light L1. In this embodiment, the light source 21 emits a pulsed laser beam having a peak wavelength in the infrared region as the primary light L1. For example, the light source 21 emits laser light having a point-like or linear beam shape as the primary light L1. The configuration of the light source 21 is not limited to this.

  The first deflecting element 22 performs an operation of deflecting the primary light L1 in a variable direction, and projects the deflected primary light L1 as a scanning light L2 toward the scanning region R0. In the present embodiment, the first deflection element 22 performs a periodic operation to periodically change the direction of deflection of the primary light L1. The first deflection element 22 emits the primary light L1 while bending the traveling direction thereof, and changes the bending direction periodically.

  In the present embodiment, the first deflecting element 22 swings around a swing axis (hereinafter, referred to as a first swing axis) X1 to reflect the primary light L1 ( (Hereinafter referred to as a first swing mirror) ML1. In this embodiment, the first deflecting element 22 periodically changes the reflection direction of the primary light L1 by swinging the first swing mirror ML1.

  Note that the scanning region R0 has a direction range corresponding to a variable range of the deflection direction of the scanning light L2 in the first deflection element 22, and a depth range corresponding to a distance at which the scanning light L2 can maintain a predetermined intensity. This is a virtual three-dimensional space. In FIG. 1, a part of the outer edge of the scanning region R0 is illustrated by a broken line.

  For example, as shown in FIG. 1, when the target object OB exists on the optical path of the scanning light L2 in the scanning region R0, the target object OB is irradiated with the scanning light L2. Further, when the object OB is an object having reflectivity to the scanning light L2, the scanning light L2 is reflected by the object OB.

  The scanning device 11 deflects the light (hereinafter, referred to as secondary light) L3 reflected or scattered by the object OB in the scanning light L2 in a direction-variable manner (hereinafter, referred to as a second deflecting element) 31. And a light receiving element 32 that receives the secondary light L3A that has passed through the second deflecting element 31.

  The second deflecting element 31 follows the first deflecting element 22 and deflects the secondary light L3 with a delay from the first deflecting element 22. In the present embodiment, the second deflecting element 32 performs a periodic operation in the same manner as the first deflecting element 22 with a delay of a predetermined time from the first deflecting element 22 to generate the secondary light L3. The deflection direction is changed periodically. The second deflection element 31 emits the secondary light L3 while bending the traveling direction thereof, and changes the bending direction periodically. The second deflection element 31 deflects the secondary light L3 and guides the secondary light L3 to the light receiving element 32.

  In the present embodiment, the second deflecting element 31 is in a direction parallel to the axial direction of the first oscillating axis X1, which is the oscillating axis of the first oscillating mirror ML1 in the first deflecting element 22. Swings about a swing axis (hereinafter, referred to as a second swing axis) X2 extending along the axis with a delay of a predetermined time from the first swing mirror ML1, and reflects the secondary light L3. And a mirror (hereinafter, referred to as a second swinging mirror) ML2.

  The light receiving element 32 performs photoelectric conversion on the secondary light L3A having passed through the second deflecting element 31, and generates an electric signal corresponding to the secondary light L3A. The light receiving element 32 has a light receiving surface 32A that receives the secondary light L3A. The light receiving element 32 outputs the generated electric signal as a result of receiving the secondary light L3.

  The scanning device 11 has a driving unit 40 that drives the light emitting unit 20 and the light receiving unit 30. The drive section 40 generates a drive signal for driving each of the light source 21, the first deflection element 22, the second deflection element 31, and the light receiving element 32, and generates the light source 21, the first deflection element 22, and the second deflection element. The driving signal is supplied to the element 31 and the light receiving element 32.

  As described above, the scanning device 11 projects the scanning light L2 toward the scanning region R0 by the light projecting unit 20, and receives the secondary light L3 from the object OB by the light receiving unit 30. Then, the scanning device 11 outputs the light receiving result of the secondary light L3, that is, the scanning result of the scanning region R0, as an electric signal.

  The distance measuring device 10 includes a distance measuring unit 12 that measures a distance to the object OB based on a result of receiving the secondary light L3A by the light receiving element 32 of the light receiving unit 30. In the present embodiment, the distance measuring unit 12 measures the distance between the scanning device 11 and the object OB, and outputs the measurement result as the distance between the distance measuring device 10 and the object OB.

  For example, the distance measuring unit 12 detects a light pulse indicating the secondary light L3 from the electric signal generated by the light receiving element 32. In addition, the distance measuring unit 12 uses the time-of-flight method based on the time difference between the light projection timing of the primary light L1 (scanning light L2) and the light reception timing of the secondary light L3 to execute the object OB (or a part thereof). The surface area is measured. Further, the distance measuring unit 12 generates data (distance measurement data) indicating the measured distance information.

  Further, in the present embodiment, the distance measuring unit 12 distinguishes the scanning region R0 into a plurality of distance measuring points (scanning points), and uses the distance measuring results (distance values) of the plurality of distance measuring points as pixels. An image (ranging image) of the indicated scanning region R0 is generated. In the present embodiment, the distance measuring unit 12 associates the distance measuring point with information indicating the displacement (oscillation position) of the first oscillating mirror ML1 and associates the two-dimensional map or the three-dimensional map of the scanning region R0 with the information. Is generated.

  Further, the distance measurement unit 12 sets, for example, a change cycle of the projection direction of the scanning light L2, that is, a scan cycle that is a cycle of scanning the scanning region R0 as a distance measurement image generation cycle, and one measurement cycle for each scan cycle. Generate a distance image.

  Note that the scanning cycle is, for example, when the scanning device 11 periodically performs optical scanning on the scanning region R0, a state of an arbitrary displacement of the first oscillating mirror ML1 of the first deflecting element 22 is changed thereafter. Means a period until it returns to the state of the displacement again. Further, the distance measurement unit 12 may include a display unit (not illustrated) that displays the generated plurality of distance measurement images as a moving image in chronological order.

  FIG. 2 is a top view of the first deflection element 22. In the present embodiment, the first deflecting element 22 is a MEMS (Micro Electro Mechanical System) mirror having the first oscillating mirror ML1. First, in the present embodiment, the first deflecting element 22 has a frame portion 22A and a swing portion 22B supported by the frame portion 22A and swinging around a first swing axis X1. The oscillating portion 22B has a pair of torsion bars each having one end fixed to the inner peripheral portion of the frame portion 22A, extending along the first oscillating axis X1, and having elasticity in the circumferential direction of the first oscillating axis X1. It has TX1.

  Further, the swing portion 22B has a swing plate SP1 connected to the other end of the pair of torsion bars TX1 so as to be able to swing around the first swing axis X1 inside the pair of torsion bars TX1. . The swing plate SP1 swings around the first swing axis X1 when the pair of torsion bars TX1 are twisted along the circumferential direction of the first swing axis X1.

  The first deflecting element 22 is, for example, a driving force generating unit (for generating a driving force of the rocking unit 22B) that electromagnetically, electrostatically, piezoelectrically, or thermally rocks the rocking plate SP1. (Not shown). The driving section 40 is connected to the terminal 22C. The oscillating portion 22B of the first deflecting element 22 oscillates upon receiving a drive signal from the driving portion 40.

  Further, the first deflection element 22 has a light reflection film 22D formed on the rocking plate SP1. The light reflection film 22D swings around the first swing axis X1 according to the swing of the swing plate SP1. In this embodiment, the light reflection film 22D has a disk shape. In the present embodiment, the light reflection film 22D functions as a first swing mirror ML1 in the first deflection element 22.

  FIG. 3 is a top view of the second deflection element 31. In this embodiment, the second deflection element 31 is a MEMS mirror. In the present embodiment, the second deflecting element 31 has a frame portion 31A and a swing portion 31B supported by the frame portion 31A and swinging around a second swing axis X2. The oscillating portion 31B has a pair of torsion bars each having one end fixed to the inner peripheral portion of the frame portion 31A, extending along the second oscillating axis X2, and having elasticity in the circumferential direction of the second oscillating axis X2. It has TX2.

  Further, the swing portion 31B has a swing plate SP2 connected to the other end of the pair of torsion bars TX2 so as to be able to swing around the second swing axis X2 inside the pair of torsion bars TX2. . The swing plate SP2 swings around the second swing axis X2 by twisting the pair of torsion bars TX2 along the circumferential direction of the second swing axis X2.

  The second deflecting element 31 is, for example, a driving force generating unit (for generating an oscillating force (ie, a driving force of the oscillating unit 31B) for electromagnetically, electrostatically, piezoelectrically, or thermally oscillating the oscillating plate SP2). (Not shown). The driving section 40 is connected to the terminal 31C. The oscillating unit 31B of the second deflecting element 31 oscillates upon receiving a drive signal from the driving unit 40.

  The second deflecting element 31 has a light reflecting film 31D formed on the oscillating plate SP2. The light reflection film 31D swings around the second swing axis X2 according to the swing of the swing plate SP2. The light reflection film 31D has a disk shape. In the present embodiment, the light reflection film 31D functions as a second swing mirror ML2 in the second deflection element 31.

  FIG. 4 is a diagram illustrating an example of an operation mode of the first and second deflection elements 22 and 31. FIG. 4 is a diagram showing a mode of the swing operation of the first swing mirror ML1 and the swing operation of the second swing mirror ML2.

  As shown in FIG. 4, in the present embodiment, first, the first swing mirror ML1 uses a non-driving displacement (a relative position with respect to the fixed portion 22A) as a reference displacement (a displacement having a displacement amount of 0). ), And swings along the circumferential direction of the first swing axis X1 with the reference displacement as the swing center. For example, the first swing mirror ML1 swings from the reference displacement at an amplitude (maximum displacement) A1 and a cycle C1.

  In this embodiment, the displacement of the first oscillating mirror ML1 refers to the perpendicular of the mirror surface (light reflecting surface) of the first oscillating mirror ML1 at the reference displacement and the first oscillating mirror at the time of displacement. The angle formed by the perpendicular of the mirror surface of the moving mirror ML1 is defined.

  Therefore, in the present embodiment, the first swing mirror ML1 sets the angle of the reference displacement to 0 °, and moves from the reference displacement in one direction in the circumferential direction of the first swing axis X1 (hereinafter, positive direction). Direction) and a displacement inclined by an angle A1 (-A1) in the other direction (hereinafter sometimes referred to as a negative direction) from the reference displacement. Rocks between.

  In the present embodiment, the first swing mirror ML1 swings while resonating so that the displacement speed (the swing speed) and the displacement direction (the direction of the swing speed) periodically change at the cycle C1. Move. Further, the first swing mirror ML1 periodically swings in the cycle C1 while alternately repeating the first period P1 displacing in the positive direction and the second period P2 displacing in the negative direction. I do. Therefore, the time change of the displacement of the first swing mirror ML1 follows a sine function, as shown in FIG. The cycle C1 corresponds to, for example, the scanning cycle of the scanning device 11.

  Next, in the present embodiment, the second oscillating mirror ML2 sets the non-driving displacement (the position relative to the fixed portion 31A) as the reference displacement (the position where the displacement amount becomes 0), and About the swing center along the circumferential direction of the second swing axis X2. For example, the second swing mirror ML2 swings from the reference displacement at an amplitude (maximum displacement) A2 and a cycle C2.

  In this embodiment, the displacement of the second oscillating mirror ML2 refers to the perpendicular of the mirror surface (light reflecting surface) of the second oscillating mirror ML2 at the reference displacement and the second oscillating mirror at the time of displacement. It refers to the angle formed by the perpendicular of the mirror surface of the moving mirror ML2.

  Therefore, in the present embodiment, the second oscillating mirror ML2 sets the angle of the reference displacement to 0 °, and moves from the reference displacement in one direction in the circumferential direction of the second oscillating axis X2 (hereinafter referred to as a positive direction). Direction) and a displacement inclined by an angle A2 (-A2) in the other direction (hereinafter sometimes referred to as a negative direction) from the reference displacement. Rocks between.

  Further, in the present embodiment, the second swing mirror ML1 swings while resonating so that the displacement speed (the swing speed) and the displacement direction (the direction of the swing speed) periodically change at the cycle C2. Move. Further, the second swinging mirror ML2 swings periodically at the cycle C2 while alternately repeating the first period of displacement in the positive direction and the second period of displacement in the negative direction. Therefore, the time change of the displacement of the second oscillating mirror ML2 follows a sine function.

  In this embodiment, the first and second deflection elements 22 and 31 have the same material and shape. The drive signals supplied from the drive unit 40 to the first and second deflection elements 22 and 31 are signals having the same frequency corresponding to the resonance frequencies of the first and second oscillating mirrors ML1 and ML2, respectively. is there. Further, the values of the amplitudes A1 and A2 at the time of the swing in the first and second swing mirrors ML1 and ML2, and the values of the swing periods C1 and C2 are equal.

  In the present embodiment, the second swing mirror ML2 swings with a phase delayed by the time D1 from the first swing mirror ML1. Therefore, the first and second oscillating mirrors ML1 and ML2 periodically oscillate in the manner and relationship shown in FIG. For example, the drive unit 40 supplies signals having different phases and similar frequencies to the first and second deflection elements 22 and 31 as drive signals.

  The time D1, that is, the time difference provided between the first and second oscillating mirrors ML1 and ML2 at the time of driving is different from the object OB separated by a reference distance (for example, a value near the middle of the measurable distance range). It can be set so as to correspond to the time when the scanning light L2 reciprocates with the distance measuring device 10. That is, during the time D1, for example, the primary light L1 is emitted from the first swinging mirror ML1 and is reflected by the object OB at a position separated by a reference distance from the first swing mirror ML1, and is received by the light receiving element 32 as the secondary light L3. Corresponding to the time it takes.

  Note that, for example, the time D1 can be calculated based on the speed (light speed) of the scanning light L2 and the distance from the distance measuring device 10 to the object OB. When the phase difference between the first and second oscillating mirrors ML1 and ML2 is the phase difference DP, the phase difference DP can be calculated by the equation DP = 2π · D1 / C1.

  As described above, in the present embodiment, the second oscillating mirror ML2 operates between the time when the primary light L1 is projected from the first deflection element 22 and the time when the secondary light L3A is received by the light receiving element 32. It swings behind the first swing mirror ML1 with a time difference corresponding to the time.

  FIG. 5A shows the operating states of the first and second oscillating mirrors ML1 and ML2 when the first oscillating mirror ML1 oscillates in the first period P1, and the reception of the secondary light L3A on the light receiving element 32. It is a figure which shows a position (indicated by the broken line) typically. FIG. 5B shows the operation states of the first and second oscillating mirrors ML1 and ML2 when the first oscillating mirror ML1 oscillates in the second period P2, and on the light receiving element 32 of the secondary light L3A. FIG. 3 is a diagram schematically showing a light receiving position (shown by a broken line). The operation of the distance measuring apparatus 10 will be described with reference to FIGS. 5A and 5B.

  First, in the first period P1, the first swing mirror ML1 swings in a positive direction (clockwise in the figure). For example, the first swing mirror ML1 receives the primary light L1 at the first timing t1, and projects the scanning light L2 by reflecting the primary light L1. Thereafter, the scanning light L2 is reflected by the object OB to become the secondary light L3, and is received by the light receiving unit 30.

  When the target object OB is located at a position separated by the reference distance, the secondary light L3 moves to the second timing t2 at the second timing t2, which is a timing after the lapse of the time D1 from the first timing t1. The light enters the moving mirror ML2.

  Here, the second swing mirror ML2 swings with a phase delayed by the time D1 from the first swing mirror ML1. That is, in the first period P1, the second swing mirror ML2 swings in the positive direction with a delay of the time D1 from the first swing mirror ML1.

  Therefore, as shown in FIG. 5A, the displacement of the first oscillating mirror ML1 at the first timing t1 substantially coincides with the displacement of the second oscillating mirror ML2 at the second timing t2.

  Further, even when the object OB is located at a position separated by a distance different from the reference distance, the secondary light L3 is transmitted to the second swing mirror ML2 with a slight time difference from the second timing t2. Incident.

  Therefore, for example, the center position of the light receiving surface 32A of the light receiving element 32 is arranged on the optical axis of the secondary light L3A when the secondary light L3 is reflected by the second oscillating mirror ML2 at the second timing t2. In this case, most of the secondary light L3 returning from various distances enters near the center of the light receiving surface 32A.

  Further, since the second oscillating mirror ML2 is oscillating following the first oscillating mirror ML1, the displacement of the first oscillating mirror ML1 at a predetermined timing and the time from the predetermined timing. The displacement of the second oscillating mirror ML2 at the timing after the lapse of D1 always substantially coincides. Therefore, the secondary light L3 corresponding to the scanning light L2 projected in the first period P1 is all incident near the center of the light receiving surface 32A.

  Therefore, for example, a position separated by the reference distance is set as a reference position, an object OB existing at the reference position is set as an object OB0, and an object OB existing at a position closer than the reference position is set as a short-distance object OB1. Consider a case where the object OB located at a position farther than the reference position is set as the object OB2 at a long distance.

  In this case, each of the secondary light L3A (OB1) from the short-distance object OB1 and the secondary light L3A (OB2) from the long-distance object OB2 is the secondary light L3A from the target object OB at the reference position. The optical path slightly deviates from (OB0) in a direction orthogonal to the axial direction of the first swing axis X1. Therefore, the secondary lights L3A (OB), L3A (OB1) and the secondary lights L3A (OB2) are respectively incident on the light receiving surface 32A at the positions shown in FIG. 5A.

  Next, as shown in FIG. 5B, in the second period P2, the first swing mirror ML1 swings in the negative direction (counterclockwise in the figure). For example, the first swing mirror ML1 receives the primary light L1 at the third timing t3, and projects the scanning light L2 by reflecting the primary light L1.

  Further, the secondary light L3 from the target object OB0 located at the reference position enters the second oscillating mirror ML2 at a fourth timing t4, which is a timing after a lapse of time D1 from the third timing t3. Will be done.

  Then, in the present embodiment, even in the second period P2, the second swing mirror ML2 swings with a delay of the time D1 from the first swing mirror ML1. That is, in the second period P2, the second swing mirror ML2 swings in the negative direction with a delay of the time D1 from the first swing mirror ML1.

  Therefore, as shown in FIG. 5B, for example, the displacement of the first swing mirror ML1 at the third timing t3 (when the scanning light L2 is projected) and the fourth timing t4 (when the secondary light L3 is received). ) Substantially coincides with the displacement of the second swing mirror ML2.

  Further, similarly to the first period P1, even when the target object OB is located at a position different from the reference position, the secondary light L3 is moved by the second swing with a slight time difference from the fourth timing t4. The light enters the moving mirror ML2.

  Accordingly, for example, on the optical axis of the secondary light L3A when the secondary light L3 is reflected by the second oscillating mirror ML2 at the second timing t2 which is an arbitrary timing in the first period P1, Even when the center position of the light receiving surface 32A of the light receiving element 32 is arranged, most of the secondary light L3 returning from the object OB within the second period P2 enters near the center of the light receiving surface 32A. Will be done.

  Note that, during the second period P2, the first swing mirror ML1 swings in the direction opposite to the first period P1. Therefore, the secondary light L3A (OB1) from the short-distance object OB1 and the secondary light L3 (OB2) from the long-distance object OB2 with respect to the secondary light L3A (OB0) from the target object OB0 at the reference position. The relationship between the incident positions on the light receiving surface 32A is symmetric between the first period P1 and the second period P2.

  Therefore, for example, in the second period P2, each of the secondary light L3A (OB0), the secondary light L3A (OB1) and the secondary light L3A (OB2) is on the light receiving surface 32A as shown in FIG. 5B. Incident on the right position.

  As described above, the second oscillating mirror ML2 (the second deflecting element 31) follows the first oscillating mirror ML1 (the first deflecting element 22) and operates with a slight delay, so that the period At any timing in C1, the optical path in the light receiving section 30 of the secondary light L3 (OB0) from the target object OB0 at the reference position can be made substantially coincident.

  Therefore, for example, by arranging the light receiving surface 32A of the light receiving element 32 in consideration of the optical path of the secondary light L3A (OB0) at the second timing t2, the secondary light L3A (OB0) is generated at any timing. The light can enter the center of the light receiving surface 32A of the light receiving element 32. Also, for example, the secondary light L3A returning from the object OB located at various positions in the scanning region R0, such as the secondary light L3A (OB1) or L3A (OB2), is at the center of the light receiving surface 32A. It can be incident near.

  Therefore, for example, by designing the light receiving surface 32A in consideration of the optical paths of all the secondary lights L3A corresponding to the primary light L1 projected within the first period P1, the light receiving surface 32A is set within the period C1 (that is, all The light receiving element 32 having an optimum shape and size to receive all the secondary lights L3A corresponding to the primary light L1 projected within the scanning cycle can be configured.

  Here, referring to FIGS. 6A and 6B, the optical path of the secondary light L3 and the case where the second oscillating mirror ML2 operates in synchronization with the first oscillating mirror ML1 (when D1 = 0) will be described. The incident position on the light receiving element will be described. Here, as the scanning device of the comparative example, instead of the light receiving unit 30 of the scanning device 11, a deflecting element 111 having an oscillating mirror that operates in synchronization with the first oscillating mirror ML1 of the first deflecting element 22 is provided. A case will be described in which a light receiving unit 110 including a light receiving element 112 that receives the secondary light L3B that has passed through the deflection element 111 is provided.

  FIG. 6A illustrates a first timing t1 (a timing at which the primary light L1 is emitted from the light emitting unit 20 within the first period P1) and a second timing t2 (the secondary light L3) in the scanning device of the comparative example. FIG. 3 is a diagram illustrating an operation state of the light projecting unit 20 and the light receiving unit 110 at a timing when light enters the light receiving unit 110). FIG. 6B is a diagram illustrating an operation state of the light projecting unit 20 and the light receiving unit 110 at the third and fourth timings t3 and t4 in the second period P2 in the scanning device of the comparative example. 6A and 6B, the position of incidence on the light receiving element 111 is indicated by a broken line.

  First, in the scanning device of the comparative example, the deflecting element 111 of the light receiving unit 110 always operates in synchronization with the first deflecting element 22 of the light projecting unit 20 (with substantially the same displacement as the first deflecting element 22). are doing. Therefore, for example, as shown in FIGS. 6A and 6B, at each of the first to fourth timings t1 to t4, the oscillating mirror of the deflecting element 111 is the same as the oscillating mirror ML1 of the first deflecting element 22. Swinging in the displaced state.

  Accordingly, for example, as shown in FIG. 6A, the displacement of the oscillating mirror of the deflecting element 111 at the second timing t2 is different from the displacement of the first oscillating mirror ML1 of the first deflecting element 22 at the first timing t1. Is different. Further, as shown in FIG. 6A, at the second timing t2, the swing mirror of the deflecting element 111 is moved clockwise by the time D1 more than the displacement of the first swing mirror ML1 at the first timing t1. Only the displacement changes.

  On the other hand, for example, as shown in FIG. 6B, the displacement of the oscillating mirror of the deflecting element 111 at the fourth timing t4 is the displacement of the first oscillating mirror ML1 of the first deflecting element 22 at the third timing t3. And different. However, as shown in FIG. 6B, at the fourth timing t4, the oscillating mirror of the deflecting element 111 takes a time D1 more counterclockwise than the displacement of the first oscillating mirror ML1 at the third timing t3. The displacement is changed by the amount.

  Therefore, for example, the secondary light L3 from the target object OB0 at the reference position becomes the secondary light L3B after passing through the deflection element 111, but the secondary light L3B is between the second timing t2 and the fourth timing t4. Follow different light paths. Specifically, in accordance with the displacement of the first deflecting element 22 and the deflecting element 111 (in this embodiment, the oscillating speed of both oscillating mirrors and the like), the secondary light L3B is supplied to the first oscillating axis. Follow the optical path displaced along the direction orthogonal to X1.

  Therefore, in the scanning device of the comparative example, even if the secondary light L3B (OB0) from the target object OB0 at the reference position, the light receiving element 112 of the secondary light L3B (OB0) between various timings within the cycle C1. The position of incidence on is shifted. In addition, for example, the secondary light L3B (OB1) from the short-distance object OB1 and the secondary light L3B (OB2) from the long-distance object OB2 are incident positions of the shifted secondary light L3B (OB0). Incident on a position further deviated from.

  In addition, as the distance to the object OB increases, the advance of the displacement of the deflection element 111 from the time of light projection increases. In particular, in the case of a deflecting element that reciprocates like the oscillating mirror of the deflecting element 111, the secondary light L3B (OB2) from the distant object OB2 in the first period P1 and the deflecting element in the second period P2 The secondary light L3B (OB2) from the object OB2 at a long distance follows an optical path far apart.

  Therefore, as shown in FIGS. 6A and 6B, when designing the light receiving surface 112A of the light receiving element 112, a large secondary light L3B (OB2) having the largest optical path deviation width within the cycle C1 is received. It is necessary to provide a light receiving surface 112A of a size. However, when the light receiving surface 112 (light receiving area) is increased, the light receiving quality is reduced due to an increase in noise light and the signal processing circuit is complicated.

  On the other hand, in the present embodiment, the second swing mirror ML2 is configured to swing with a delay of the time D1 from the first swing mirror ML1. Therefore, the displacement of the optical path of the secondary light L3A guided to the light receiving element 32 can be minimized regardless of the position, speed, and direction of the swing of the first swing mirror ML1.

  Therefore, the size and shape of the light receiving element 32 can be optimized. Therefore, for example, it is possible to accurately and reliably receive the reflected light from the object OB while reducing the size of the light receiving element 32. Further, accurate scanning information of the scanning region R0 can be obtained, and accurate ranging information of the object OB can be obtained.

  In the present embodiment, the second swing axis X2 extends around the second swing axis X2 extending parallel to the axial direction of the first swing axis X1 which is the swing axis of the first swing mirror ML1. The case where the mirror ML2 is configured to swing is described.

  However, the first and second swing mirrors ML1 and ML2 are not limited to the case where the first and second swing mirrors ML1 and ML2 are configured to swing around swing axes that are completely parallel to each other. The second swing mirror ML2 may be configured and arranged to swing around a second swing axis X2 extending along a direction corresponding to the axial direction of the first swing axis X1. .

  In the present embodiment, the second oscillating mirror ML2 is delayed from the first oscillating mirror ML1 by a time difference corresponding to the time when the scanning light L2 reciprocates with the object OB separated by the reference distance. The case of swinging has been described. That is, the second oscillating mirror ML2 has a first time difference corresponding to the time from when the primary light L1 is projected from the first deflecting element 22 to when the secondary light L3 is received by the light receiving element 32. The case of swinging with a delay from the swinging mirror ML1 has been described.

  However, the delay time D1 corresponding to the phase difference provided between the first and second oscillating mirrors ML1 and ML2 may be finely adjusted. For example, the drive unit 40 is configured to drive each of the first and second oscillating mirrors ML1 and ML2 while adjusting the phase difference between the first and second oscillating mirrors ML1 and ML2. Is also good. Thereby, for example, even when the distance measuring device 10 is used under various conditions or environments, it is possible to suppress the shift of the incident position of the secondary light L3A on the light receiving element 32.

  In the present embodiment, the case where the first and second deflecting elements 22 and 31 are MEMS mirrors has been described. However, each of the first and second deflecting elements 22 and 31 only needs to have a oscillating mirror (first and second oscillating mirrors ML1 and ML2). For example, the first and second deflection elements 22 or 31 may be galvanomirrors.

  FIG. 7 is a diagram illustrating the configuration of the distance measuring device 10A according to the first modification of the first embodiment. The distance measuring device 10A has the same configuration as the distance measuring device 10 except for the configuration of the scanning device 11A. The scanning device 11A has the same configuration as that of the scanning device 11, except for the configuration of the light projecting unit 20A, the light receiving unit 30A, and the driving unit 40A that drives them.

  The light projecting unit 20A has the same configuration as the light projecting unit 20 except for the configuration of the first deflecting element 22M. The light receiving unit 30A has the same configuration as the light receiving unit 30, except for the configuration of the second deflection element 31M.

  The first deflecting element 22M has a first oscillating mirror ML11 that oscillates about first and second oscillating axes X1 and Y1 orthogonal to each other. The first oscillating mirror ML11 reflects the primary light L1 in a variable direction, and projects the reflected primary light L1 as a scanning light L2 toward the scanning region R0.

  The second deflecting element 31M has a second oscillating mirror ML21 that oscillates around third and fourth oscillating axes X2 and Y2 orthogonal to each other. In the present embodiment, the second swing mirror ML21 is arranged so that the third swing axis X2 is parallel to the axial direction of the first swing axis X1. The second swing mirror ML21 swings with a phase delayed from the first swing mirror ML11.

  The first oscillating mirror ML11 oscillates while resonating around the first and second oscillating axes X1 and Y1, for example, so that the direction of the optical axis changes in a trajectory corresponding to the Lissajous scan. The next light L1 is reflected. The second swing mirror ML21 swings around the third and fourth swing axes X2 and Y2 in the same manner as the first swing mirror ML11.

  FIG. 8 is a top view of the first deflection element 22M. FIG. 9 is a top view of the second deflection element 31M. A configuration example of the first and second deflection elements 22M and 31M will be described with reference to FIGS.

  First, as shown in FIG. 8, the first deflecting element 22M has a frame portion 22A and a swing portion 22BM swingably supported by the frame portion 22A.

  The swing part 22BM has a pair of torsion bars TY1 whose one ends are fixed to the inner peripheral part of the frame part 22A, extend along the second swing axis Y1, and have elasticity in the circumferential direction of the second swing axis Y1. Having. Further, the swing part 22BM is connected to the other end of the pair of torsion bars TY1, and has a swing frame SY1 that swings around the second swing axis Y1.

  In addition, the swing portion 22BM has a pair of ends connected to the inner peripheral portion of the swing frame SY1, extends along the first swing axis X1, and has elasticity in the circumferential direction of the first swing axis X1. It has a torsion bar TX1. Further, the swing unit 22BM has a swing plate SP1M connected to the other end of the pair of torsion bars TX1. Therefore, the swing plate SP1M of the swing unit 22BM swings around the first and second swing axes X1 and Y1.

  The first deflecting element 22M has a light reflection film 22CM formed on the oscillating plate SP1M of the oscillating portion 22BM. The light reflection film 22CM swings around the first and second swing axes X1 and Y1 according to the swing of the swing plate SP1M.

  The light reflection film 22CM has a swing center CA1 at the intersection of the first and second swing axes X1 and Y1 when viewed from a direction perpendicular to the swing plate SP1M. The light reflection film 22CM functions as a first swing mirror ML11 in the first deflection element 22M.

  In this modification, the first deflecting element 22M includes a driving force generating unit (not shown) that generates a oscillating force (driving force) that oscillates the oscillating plate SP1M, and a driving force generating unit (not shown). It has a terminal 22DM connected to the drive section 40A. Therefore, the first swing mirror ML11 swings around the first and second swing axes X1 and Y1 according to the drive signal supplied from the drive unit 40A.

  As shown in FIG. 9, the second deflecting element 31M has a frame portion 31A and a swing portion 22BM swingably supported by the frame portion 31A.

  The swinging portion 31BM has a pair of torsion bars TY2 each having one end fixed to the inner peripheral portion of the frame portion 31A, extending along the fourth swinging axis Y2, and having elasticity in the circumferential direction of the fourth swinging axis Y2. Having. Further, the swing portion 31BM is connected to the other end of the pair of torsion bars TY2, and has a swing frame SY2 that swings around the fourth swing axis Y2.

  The swing portion 31BM has one end connected to the inner peripheral portion of the swing frame SY2, extends along the third swing axis X2, and has a pair of elasticity in the circumferential direction of the 32nd swing axis X2. It has a torsion bar TX2. Further, the swing unit 31BM has a swing plate SP2M connected to the other end of the pair of torsion bars TX2. Therefore, the swing plate SP2M of the swing unit 31BM swings around the third and third swing axes X2 and Y2.

  The second deflecting element 31M has a light reflection film 31CM formed on the oscillating plate SP2M of the oscillating portion 31BM. The light reflection film 31CM swings around the third and fourth swing axes X2 and Y2 according to the swing of the swing plate SP2M.

  The light reflection film 31CM has a swing center CA2 at the intersection of the third and fourth swing axes X2 and Y2 when viewed from a direction perpendicular to the swing plate SP2M. The light reflection film 31CM functions as the second swing mirror ML21 in the second deflection element 31M.

  In this modification, the second deflecting element 31M includes a driving force generation unit (not shown) that generates a oscillating force (driving force) for oscillating the oscillating plate SP2M, and a driving force generation unit (not shown). It has a terminal 31DM that is connected to the drive section 40A. Therefore, the second swing mirror ML21 swings around the third and fourth swing axes X1 and Y1 according to the drive signal supplied from the drive unit 40A.

  FIG. 10 is a top view schematically illustrating the light receiving surface 32A of the light receiving element 32 in the scanning device 11. FIG. 10 shows a state in which the first oscillating mirror ML11 is oscillating in an arbitrary direction (for example, both positive directions) around the first and second oscillating axes X1 and Y1 from the object OB during the period. It is a figure which shows typically the incident position on the light receiving surface 32A of reflected light L3 of FIG.

  Even when the first and second oscillating mirrors ML11 and ML21 oscillate around a plurality of oscillating axes as in the present modification, the second oscillating mirror ML21 is separated from the first oscillating mirror ML11. It swings with a delay of time D1. Therefore, first, the secondary light L3A (OB0) from the target object OB0 at the reference position is within a very narrow desired area (for example, a design center area) of the light receiving surface 32A at any timing within the oscillation cycle. Will be incident.

  Also, in the secondary light L3A (OB1) from the short-distance object OB1 and the secondary light L3A (OB2) from the long-distance object OB2, the incident position on the light receiving surface 32A is the target position of the reference position. Although slightly shifted two-dimensionally from the incident position of the secondary light L3A (OB0) from the object OB0, it is incident on the light receiving surface 32A in the vicinity of the desired area.

  On the other hand, FIG. 11 shows, as a comparative example, a scan having a deflecting element having a oscillating mirror oscillating in synchronization with the first oscillating mirror ML11 and a light receiving element 112 for receiving the secondary light L3B passing through the deflecting element. FIG. 3 is a top view of a light receiving surface 112A of a light receiving element 112 in the device. FIG. 11 is a diagram schematically illustrating an incident position of the secondary light L3B on the light receiving surface 112A during a period in which the first swing mirror ML11 performs the same swing as in FIG.

  In the scanning device according to the comparative example, for example, as illustrated in FIG. 11, the secondary light L3B (OB0) from the target object OB0 at the reference position travels two-dimensionally different optical paths toward the light receiving element 112. It will be.

  Therefore, not only the secondary light L3B (OB0), but also the light receiving surface of the secondary light L3B (OB1) from the short-distance object OB1 and the secondary light L3B (OB2) from the long-distance object OB2. The incident position on 112A is greatly shifted two-dimensionally. Therefore, when providing the light receiving surface 112A on the light receiving element 112, as shown in FIG. 11, it is necessary to provide a light receiving surface 112A having a two-dimensionally large size to receive all of them.

  On the other hand, even when the first swing mirror ML11 swings around two swing axes as in the present modification, the second swing mirror ML21 swings following the displacement. . Therefore, the secondary light L3 from the object OB at various positions can be made incident on a desired region of the light receiving surface 32A.

  Therefore, also in the present modification, the size of the light receiving element 32 can be significantly reduced, and the reception of noise light is greatly suppressed. Therefore, it is possible to provide the scanning device 11A and the distance measuring device 10A that can accurately and surely receive the reflected light L3 from the object OB, and that can perform accurate scanning and distance measurement.

  Note that the configuration and the swing mode of each of the first and second swing mirrors ML11 and ML21 are not limited thereto. For example, the first swing mirror ML11 is configured to swing while resonating around the first swing axis X1, and swing around the second swing axis Y1 non-resonantly. You may. In this case, the first swing mirror ML11 reflects the primary light L1 such that the direction of the optical axis changes in a trajectory corresponding to the raster scan. Further, each of the first and second swing mirrors ML11 and ML21 is not limited to the case where the first and second swing mirrors swing about the swing axes orthogonal to each other.

  In other words, the first deflecting element 22M swings around two different swing axes (first and second swing axes X1 and Y1) and reflects the primary light L1. What is necessary is just to have the rocking mirror ML11.

  The second deflecting element 31M has a direction corresponding to the axial direction of the third swing axis X2 and the second swing axis Y1 extending along the direction corresponding to the axial direction of the first swing axis X1. A second oscillating mirror ML21 that oscillates about the fourth oscillating axis Y2 extending along the axis with a delay of the time D1 from the first oscillating mirror ML11 and reflects the secondary light L3. Just fine. Accordingly, it is possible to provide the scanning device 11A and the distance measuring device 10A that can accurately and reliably receive the reflected light from the object OB while reducing the size of the light receiving element 32, and can perform accurate scanning and distance measurement. it can.

  FIG. 12 is a diagram illustrating a configuration of a distance measuring apparatus 10B according to a second modification of the first embodiment. The distance measuring device 10B has the same configuration as the distance measuring device 10 except for the configuration of the scanning device 11B. The scanning device 11B has the same configuration as the scanning device 11 except for the configuration of the light projecting unit 20B, the light receiving unit 30B, and the driving unit 40B that drives them.

  The light projecting unit 20B has the same configuration as the light projecting unit 20 except for the configuration of the first deflection element 23. The light receiving unit 30B has the same configuration as the light receiving unit 30 except for the configuration of the second deflection element 33.

  The first deflection element 23 rotates around a rotation axis (hereinafter, referred to as a first rotation axis) X1 and reflects a primary light L1 (hereinafter, a first rotation mirror). ) The ML12 is provided. The second deflecting element 33 is provided around a rotation axis (hereinafter, referred to as a second rotation axis) X2 extending along a direction corresponding to the axial direction of the first rotation axis X1. A turning mirror (hereinafter, referred to as a second turning mirror) ML22 that turns after being delayed by the time D1 from the turning mirror ML12 and reflects the secondary light L3. Each of the first and second turning mirrors ML12 and ML22 is composed of, for example, a polygon mirror.

  Further, the scanning device 11B includes a driving unit 40B that drives the light emitting unit 20B and the light receiving unit 30B. The drive unit 40B generates a control signal for rotating the first and second rotating mirrors ML12 and ML22 and controlling the rotating operation. Each of the first and second rotation mirrors ML12 and ML22 receives the control signal and rotates with a different phase.

  Even in the case where the first and second deflecting elements 23 and 33 perform the light deflecting operation by the first and second turning mirrors ML12 and ML22 as in the present modification, the phases thereof are adjusted. By doing so, the position where the secondary light L3A is incident on the light receiving element 32 can be adjusted. Accordingly, by reducing the size of the light receiving element 32, noise incident on the light receiving element 32 can be reduced, and thereby accurate scanning and distance measurement can be performed.

  Further, for example, by performing the phase adjustment of the second rotation mirror ML22, it is possible to finely adjust the positional relationship between the optical axis of the secondary light L3A and the light receiving element 32. That is, for example, there is no need to provide a mechanism (not shown) for mechanically adjusting the mounting position of the light receiving element 32 in the distance measuring device 10. This is a similar advantage for other modifications and embodiments (for example, in the case of a swinging mirror).

  In the present embodiment and its various modifications, the light projecting units 20, 20A and 20B and the light receiving units 30, 30A and 30B are separated. However, the first deflecting elements 21, 21M and 23 and the second deflecting elements 31, 31M and 33 may be provided in a common housing. In other words, for example, if the scanning device 11, 11A and 11B has the light source 21, the first deflecting elements 21, 21M and 23, the second deflecting elements 31, 31M and 33, and the light receiving element 32 Good.

  Further, in the present embodiment and its various modifications, the case where the first deflecting elements 21, 21M and 23 and the second deflecting elements 31, 31M and 33 have a swinging mirror or a rotating mirror has been described. However, the first deflecting elements 21, 21M and 23 and the second deflecting elements 31, 31M and 33 may be any deflecting element that operates in various modes to deflect light.

  For example, the first deflecting element that deflects the primary light L1 performs a periodic operation to periodically change the direction of deflection of the primary light L1, and uses the deflected primary light L1 as a scanning light L2. What is necessary is just to be comprised so that light may be projected. The second deflecting element that deflects the secondary light L2, for example, deflects the secondary light L3 in which the scanning light L2 is reflected by the object OB in a variable direction, and deviates from the first deflecting element for a time D1. It is sufficient that the configuration is such that a periodic operation similar to that of the first deflection element is performed with a delay to periodically change the deflection direction of the secondary light L3. For example, the first and second deflection elements may be various optical elements such as periodically movable lenses.

  Further, the first and second deflecting elements are not limited to the case where they are configured to perform a periodic operation. For example, the scanning device 11 may be configured to scan the scanning region R0 in a periodic manner like a vector scan. Further, even when performing the raster scan and the Lissajous scan, different regions may be scanned for each cycle C1.

  In this case, the first deflecting element 22 is configured to emit the primary light L1 (scanning light L2) a specific number of times on a specific trajectory in accordance with a drive signal from the drive unit 40. In this case, the second deflecting element may deflect the secondary light L3 in a variable direction by following the first deflecting element and operating with a delay from the first deflecting element. Thus, even when the first deflection element 22 does not perform a periodic operation, the incident position of the secondary light L3 on the light receiving element 32 can be stabilized.

  As described above, the distance measuring device 10 (10A, 10B) performs the light source 21 that emits the primary light L1, the operation of deflecting the primary light L1 in a variable direction, and scans the deflected primary light L1. The first deflecting element 22 (22M, 23) that emits the light L2 and the secondary light L3, which is the scanning light L2 reflected by the object OB, are variably deflected and follow the first deflecting element 22. A second deflecting element 31 (31M, 33) that operates with a delay from the first deflecting element 22, a light receiving element 32 that receives the secondary light L3A passing through the second deflecting element 31, and a light receiving element 32 A distance measuring unit 12 for measuring a distance to the object OB based on a result of receiving the next light L3A. Therefore, it is possible to provide the distance measuring apparatus 10 that can accurately and surely receive the reflected light from the object OB while miniaturizing the light receiving element 32 and perform accurate scanning and distance measurement.

  Further, for example, the scanning device 11 functions as a scanning device that outputs an accurate result of receiving the secondary light L3 as scanning information according to various uses. Therefore, for example, the scanning device 11 includes the light source 21, the first deflecting element 22, the second deflecting element 31, and the light receiving element 32, thereby reducing the size of the light receiving element 32 and reducing the reflected light L3 from the object OB. The scanning device can receive light accurately and reliably and can perform accurate scanning.

  That is, for example, the scanning device 11 performs an operation of variably deflecting the primary light L1 with the light source 21 that emits the primary light L1, and projects the deflected primary light L1 as the scanning light L2. The first deflecting element 22 and the scanning light L2 deflect the secondary light L3 reflected by the object OB in a variable direction, follow the first deflecting element 22, and operate with a delay from the first deflecting element 22. And a light receiving element 32 that receives the secondary light L3A passing through the second deflecting element 31. Accordingly, it is possible to provide the scanning device 11 that can accurately and reliably receive the reflected light from the object OB while reducing the size of the light receiving element 32, and can perform accurate scanning.

  In addition, the present invention can be implemented, for example, as a driving method for driving the scanning device 11. That is, for example, in the driving method of the scanning device according to the present invention, the light source 21 that emits the primary light L1 and the operation of deflecting the primary light L1 in a variable direction are performed, and the deflected primary light L1 is scanned by the scanning light. A first deflecting element 22 that emits light as L2, a second deflecting element 31 that performs an operation of variably deflecting the secondary light L3 reflected by the object OB with the scanning light L2, and a second deflecting element And a light receiving element 32 for receiving the secondary light L3A passing through the first deflecting element 31. The second deflecting element 31 follows the first deflecting element 22 and has a first deflecting element 32. 22. The operation having a delay from 22. Accordingly, it is possible to provide a driving method of the scanning device 11 that can accurately and surely receive the reflected light from the object OB while reducing the size of the light receiving element 32 and can perform accurate scanning.

  In addition, the present invention can be implemented, for example, as a program that causes a computer to function as the driving unit 40 of the scanning device 11. That is, for example, the program according to the present invention is configured such that the computer performs an operation of deflecting the primary light L1 in a direction variably with the light source 21 for emitting the primary light L1, and converts the deflected primary light L1 to the scanning light L2. A first deflecting element 22 for projecting light, a second deflecting element 31 for performing an operation of variably deflecting the secondary light L3 reflected by the object OB with the scanning light L2, and a second deflecting element 31 And the light receiving element 32 that receives the secondary light L3A that has passed through the scanning device 11 such that the second deflecting element 31 operates following the first deflecting element 22 and lagging behind the first deflecting element 22. Then, it is made to function as a driving unit 40 for driving. Further, the present invention can be implemented, for example, as a recording medium in which the above-described program is recorded.

  Accordingly, it is possible to provide a drive program and a recording medium for the scanning device 11 that can accurately and reliably receive reflected light from the object OB while reducing the size of the light receiving element 32 and perform accurate scanning.

  FIG. 13 is a diagram illustrating the configuration of the distance measuring apparatus 50 according to the second embodiment. The distance measuring device 50 has the same configuration as the distance measuring device 10 except for the configuration of the scanning device 51. The scanning device 51 has the same configuration as the scanning device 11 except for the configurations of the light receiving unit 60 and the driving unit 40C. In this embodiment, the light receiving section 60 has the same configuration as the light receiving section 30 except for the configuration of the second deflection element 61.

  The second deflection element 61 has a plurality of oscillating mirrors ML23 and ML31. Specifically, the second deflecting element 61 is a swing mirror (hereinafter, referred to as a second swing mirror) that swings around a swing axis (hereinafter, referred to as a second swing axis) X2. A mirror element 61A having an ML31 and a mirror element having an oscillating mirror (hereinafter, referred to as a third oscillating mirror) ML23 oscillating around an oscillating axis (hereinafter, referred to as a third oscillating axis) X3. 61B.

  That is, in the present embodiment, the second deflecting element 61 of the light receiving section 60 has a plurality of oscillating mirrors. In this case, the entire second deflection element 61 may follow the first deflection element 22 and operate with a delay from the first deflection element 22 to change the deflection direction of the secondary light L3.

  For example, in the present embodiment, the first deflecting element 22 has a first oscillating mirror ML13 that oscillates around the first oscillating axis X1 and reflects the primary light L1. The second deflecting element 61 oscillates in synchronization with the first oscillating mirror ML13 around a second oscillating axis X2 extending along a direction corresponding to the axial direction of the first oscillating axis X1. A second oscillating mirror ML31 for moving and reflecting the secondary light L3, and a second oscillating mirror ML31 around a third oscillating axis X3 extending along a direction corresponding to the axial direction of the second oscillating axis X2. A third oscillating mirror ML23 that oscillates later than the oscillating mirror ML31 and reflects the secondary light L3 that has passed through the second oscillating mirror ML31.

  For example, the first and second swing mirrors ML13 and ML31 perform the same swing operation in synchronization with each other. On the other hand, the third oscillating mirror ML23 has a phase shifted (for example, delayed) by about π / 2 with respect to the second oscillating mirror ML31 in the direction of the oscillating speed of the second oscillating mirror ML31. A swing operation similar to that of the second swing mirror ML31 is performed in the direction based on the swing direction. Note that the relationship of the swing mode (for example, phase difference) between the first, second, and third swing mirrors ML13, ML31, and ML23 is not limited to this.

  The drive unit 40C drives the light projecting unit 20 and the light receiving unit 60 to swing the first swing mirror ML13, the second swing mirror ML31, and the third swing mirror ML23, and swings the swing mirrors. A control signal to control the operation. The first oscillating mirror ML13, the second oscillating mirror ML31, and the third oscillating mirror ML23, upon receiving the control signal, oscillate with, for example, the above-described phase difference.

  In the present embodiment, the light receiving element 32 receives the secondary light L3A that has passed through the third swing mirror ML23. Even when the first and second deflecting elements 22 and 61 have such a configuration, it is possible to suppress the displacement of the position of the secondary light L3A incident on the light receiving element 32 on the light receiving surface 32A. Therefore, for example, it is possible to provide a scanning device 51 and a distance measuring device 50 that can accurately and surely receive reflected light from the object OB while miniaturizing the light receiving element 32 and perform accurate scanning and distance measurement. Can be.

  In the present embodiment, the case has been described where the secondary light L3 is received by the light receiving element 32 after traveling through the second oscillating mirror ML13 and the third oscillating mirror ML23 in this order. However, the second deflection element 61 may be configured and arranged so as to guide the secondary light L3 to the light receiving element 32. For example, the second deflecting element 61 deflects (reflects) the secondary light L3 by the third oscillating mirror ML23 and then deflects (reflects) it by the second oscillating mirror ML31. 32 may be configured and arranged.

  FIG. 14 is a diagram illustrating the configuration of the distance measuring apparatus 70 according to the third embodiment. The ranging device 70 has the same configuration as the ranging device 10 except for the configuration of the scanning device 71. The scanning device 71 has a light emitting unit 80, a light receiving unit 90, and a driving unit 40D. In the present embodiment, the light projecting unit 80 has the same configuration as the light projecting unit 20 except for the configuration of the first deflection element 81. The light receiver 90 has the same configuration as the light receiver 30 except for the configuration of the second deflection element 91.

  In the present embodiment, the first deflection element 81 has a plurality of oscillating mirrors ML14 and ML24. Specifically, the first deflecting element 81 is a swing mirror (hereinafter, referred to as a first swing mirror) that swings around a swing axis (hereinafter, referred to as a first swing axis) X1. A mirror element 81A having an ML14 and a mirror element having a swing mirror (hereinafter, referred to as a second swing mirror) ML24 swinging around a swing axis (hereinafter, referred to as a second swing axis) X2. 91B.

  Further, in the present embodiment, the second deflecting element 91 of the light receiving section 90 includes a swing mirror (hereinafter, referred to as a third swing axis) that swings around a swing axis (hereinafter, referred to as a third swing axis) X3. ML32).

  That is, in this embodiment, the first deflecting element 81 of the light projecting unit 80 has a plurality of oscillating mirrors. In this case, the operation between the entire first deflection element 81 and the second deflection element 91 may be adjusted. For example, the second deflection element 91 may follow the first deflection element 81 and operate with a delay from the first deflection element 81 to change the direction of deflection of the secondary light L3.

  For example, in this embodiment, the first deflecting element 81 swings around the first swing axis X1 and reflects the primary light L1 with the first swing mirror ML14 and the first swing mirror ML14. Primary light that oscillates about a second oscillating axis X2 extending along a direction corresponding to the axial direction of the moving axis X1 with a delay from the first oscillating mirror ML14, and has passed through the first oscillating mirror ML14. A second oscillating mirror ML24 that reflects L1. For example, the first swing mirror ML14 swings in a direction based on the direction of the swing speed of the second swing mirror ML24.

  In the present embodiment, the second deflecting element 91 includes a second oscillating mirror around a third oscillating axis X3 extending along a direction corresponding to the axial direction of the second oscillating axis X2. A third swing mirror ML32 that swings in synchronization with the ML24 and reflects the secondary light L3.

  For example, the second and third swing mirrors ML24 and ML32 perform the same swing operation in synchronization with each other. On the other hand, the first swing mirror ML14 performs a swing operation with a phase shifted (for example, advanced) by about π / 2 with respect to the second swing mirror ML24. Note that the relationship of the swing mode (for example, phase difference) between the first, second, and third swing mirrors ML14, ML24, and ML32 is not limited to this.

  The driving unit 40D drives the light projecting unit 80 and the light receiving unit 90 to swing the first swing mirror ML14, the second swing mirror ML24, and the third swing mirror ML32, and swings the swinging mirrors. A control signal to control the operation. The first oscillating mirror ML14, the second oscillating mirror ML24, and the third oscillating mirror ML32, upon receiving the control signal, oscillate with, for example, the above-described phase difference.

  In the present embodiment, the light receiving element 32 receives the secondary light L3A having passed through the third swing mirror ML32. Even when the first and second deflection elements 81 and 91 have such a configuration, it is possible to suppress the displacement of the position of the secondary light L3A incident on the light receiving element 32 on the light receiving surface 32A. Therefore, for example, it is possible to provide a scanning device 71 and a distance measuring device 70 that can accurately and surely receive reflected light from the object OB while miniaturizing the light receiving element 32 and perform accurate scanning and distance measurement. Can be.

  In this embodiment, the case has been described where the primary light L1 is received as the scanning light L2 after traveling through the first swing mirror ML14 and the second swing mirror ML24 in this order. However, the first deflecting element 81 may be configured and arranged so as to deflect the primary light L3 and project it as the scanning light L2. For example, the first deflecting element 81 deflects (reflects) the primary light L3 by the second oscillating mirror ML24 and then deflects (reflects) it by the first oscillating mirror ML14. It may be configured and arranged to project light toward R0.

10, 10A, 10B, 50, 70 Distance measuring device 11, 11A, 11B, 51, 71 Scanning device 21 Light source 22, 22M, 23, 81 First deflecting element 31, 31M, 33, 61, 91 Second deflection Element 32 Light receiving element 12 Distance measuring unit

Claims (13)

A light source for emitting primary light,
A first deflection element that performs an operation of deflecting the primary light in a variable direction, and projects the deflected primary light as scanning light;
A second deflecting element in which the scanning light deflects the secondary light reflected by the object in a variable direction, follows the first deflecting element, and operates with a delay from the first deflecting element;
A light receiving element for receiving the secondary light having passed through the second deflecting element. The first deflecting element performs a periodic operation to periodically change a deflecting direction of the primary light,
The second deflecting element performs a periodic operation in a manner similar to that of the first deflecting element after the first deflecting element to periodically change the deflecting direction of the secondary light. Scanning device characterized. The first deflection element has a first swing mirror that swings around a first swing axis and reflects the primary light,
The second deflecting element oscillates with a delay from the first oscillating mirror around a second oscillating axis extending along a direction corresponding to an axial direction of the first oscillating axis; The scanning device according to claim 1, further comprising a second oscillating mirror that reflects secondary light.   The second oscillating mirror has a phase difference corresponding to a time from when the primary light is projected from the first deflecting element to when the secondary light is received by the light receiving element. 4. The scanning device according to claim 3, wherein the scanning device swings with a delay from the swing mirror.   The apparatus according to claim 3, further comprising a driving unit configured to drive each of the first and second oscillating mirrors while adjusting a phase difference between the first and second oscillating mirrors. Scanning device. The first deflection element has a first swing mirror that swings around a first swing axis and reflects the primary light,
The second deflecting element oscillates in synchronization with the first oscillating mirror around a second oscillating axis extending along a direction corresponding to an axial direction of the first oscillating axis; A second oscillating mirror for reflecting the secondary light, and a second oscillating mirror around a third oscillating axis extending along a direction corresponding to an axial direction of the second oscillating axis. The scanning device according to claim 1, further comprising a third swing mirror that swings with a delay and reflects the secondary light that has passed through the second swing mirror. A first oscillating mirror that oscillates about a first oscillating axis and reflects the primary light, and a direction corresponding to an axial direction of the first oscillating axis. A second oscillating mirror that oscillates about a second oscillating axis extending along with the first oscillating mirror and reflects the primary light passing through the first oscillating mirror; , And
The second deflecting element oscillates in synchronization with the second oscillating mirror around a third oscillating axis extending along a direction corresponding to an axial direction of the second oscillating axis; The scanning device according to claim 1, further comprising a third oscillating mirror that reflects the secondary light. The first deflecting element has a first oscillating mirror that oscillates around first and second oscillating axes different from each other and reflects the primary light,
The second deflecting element extends along a direction corresponding to an axial direction of the third oscillating shaft and a second oscillating axis extending along a direction corresponding to the axial direction of the first oscillating shaft. 3. The apparatus according to claim 1, further comprising a second oscillating mirror that oscillates about the extending fourth oscillating axis with a delay from the first oscillating mirror and reflects the secondary light. A scanning device according to claim 1. The first deflecting element has a first turning mirror that turns around a first turning axis and reflects the primary light,
The second deflecting element rotates with a delay from the first rotation mirror around a second rotation axis extending along a direction corresponding to the axial direction of the first rotation axis, The scanning device according to claim 1, further comprising a second rotating mirror that reflects secondary light. A scanning device according to any one of claims 1 to 9,
A distance measuring unit for measuring a distance to the object based on a result of receiving the secondary light by the light receiving element. A light source that emits primary light, a first deflecting element that performs an operation of deflecting the primary light in a variable direction and projects the deflected primary light as scanning light, and the scanning light is an object. For driving a scanning device having a second deflecting element for performing an operation of deflecting the secondary light reflected by the light source in a variable direction, and a light receiving element for receiving the secondary light having passed through the second deflecting element And
The method of claim 2, wherein the second deflecting element follows the first deflecting element and operates behind the first deflecting element. Computer
A light source that emits primary light, a first deflecting element that performs an operation of deflecting the primary light in a variable direction and projects the deflected primary light as scanning light, and the scanning light is an object. A scanning device having a second deflecting element that performs an operation of deflecting the secondary light reflected by the light beam in a variable direction, and a light receiving element that receives the secondary light. A program that functions as a driving unit that drives so as to follow the deflection element and operate with a delay from the first deflection element.   A recording medium on which the program according to claim 12 is recorded.