JP2009270856A - Ranging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce cost of a ranging device having a vibration isolation function. <P>SOLUTION: This ranging device 1 includes a transmission optical system 10 for projecting laser light L1 toward a target object, and a reception optical system 30 for receiving reflected laser light L2 reflected by the target object by a light receiving element 34. When optical axes 2, 4 are tilted by camera shake or the like, a vibration isolation lens 14 disposed in the transmission optical system 10 is displaced as shown by M1 by a driving mechanism 42, to thereby deflect a beam. A vibration isolation lens 32 disposed in the reception optical system 30 is displaced as shown by M2 by a driving mechanism 43 in linkage with the driving mechanism 42, wherein M2 is a motion rougher than M1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a distance measuring device that measures a distance to a target object, and more particularly to a distance measuring device that is used by hand.

  As a distance measuring device, an apparatus for measuring a distance to a target object from a time difference between when a laser beam is projected onto a target object and when a reflected laser beam from the target object is received is known. In a hand-held distance measuring device, the optical axis of the optical system is inclined due to camera shake, making it difficult to continuously apply laser light to a target object. Conventionally, a laser range finder is known in which optical elements constituting an optical system of a transmission unit and a reception unit are fixed to an apparatus main body via a gimbal in order to correct an optical axis tilt due to camera shake ( For example, see Patent Document 1).

JP 2004-101342 A

  In the laser range finder disclosed in Patent Document 1, since one gimbal accommodates both the optical element of the transmitting unit and the optical element of the receiving unit, the vibration isolating performance of the receiving unit is high, but the gimbal itself is heavier and larger and manufactured. Costs will also increase. On the other hand, in other methods, if the same performance as that of the reception unit and the transmission unit is used, the cost of the image stabilization mechanism is simply doubled.

(1) A distance measuring device according to a first aspect of the present invention includes a transmission optical system that projects signal light toward a target object, and a reception optical system that receives reflected light of the signal light reflected by the target object by a light receiving element. In a distance measuring device that measures the distance to a target object based on the time from the projection of the signal light to the reception of the reflected light, the light beam is deflected to the transmission optical system in accordance with the change in the direction of the optical axis with respect to the target object. A first image stabilization mechanism for performing an image stabilization operation is provided, and a second image stabilization mechanism for performing an image stabilization operation with lower accuracy than the first image stabilization mechanism is provided in the reception optical system. .
(2) The invention according to claim 2 is the distance measuring device according to claim 1, wherein the second vibration isolation mechanism operates with a reduction in accuracy to a range where the light receiving element can receive the reflected light. It is characterized by.
(3) The invention of claim 3 is the distance measuring device according to claim 1 or 2, further comprising a collimation optical system for collimating the target object, wherein the collimation optical system and the transmission optical system are A synthesizing optical system that shares part of the optical axis is configured on the target object side of the branching optical element that separates the optical system, and the synthesizing optical system is provided with a first vibration isolation mechanism.
(4) According to a fourth aspect of the present invention, in the distance measuring device according to any one of the first to third aspects, the first vibration isolation mechanism includes the first optical element disposed in the transmission optical system. It has a first drive mechanism for driving, and the second vibration isolation mechanism has a second drive mechanism for driving a second optical element disposed on the optical path of the reception optical system. .
(5) A fifth aspect of the invention is the distance measuring device according to any one of the first to third aspects, wherein the first optical element provided in the transmission optical system and the reception optical system are provided. The second optical element is mechanically coupled, the first vibration isolation mechanism drives the first optical element, and the second vibration isolation mechanism is mechanically coupled to the first vibration isolation mechanism. And driving the second optical element.
(6) The invention according to claim 6 is the distance measuring device according to claim 4 or 5, wherein the first and second optical elements are optical elements that are displaced in a direction perpendicular to the optical axis by driving. And
(7) The invention according to claim 7 is the distance measuring device according to claim 4 or 5, wherein the first and second optical elements are angles of apex angles which are angles formed by the incident surface and the exit surface by driving. It is a variable apex angle prism that changes the angle.

  According to the distance measuring apparatus of the present invention, the image stabilizing operation of the receiving optical system is operated following the image stabilizing operation of the transmitting optical system, while the image stabilizing mechanism of the receiving optical system is used with low accuracy. By doing so, cost reduction can be achieved.

Hereinafter, a distance measuring device according to an embodiment of the present invention will be described with reference to FIGS.
<First Embodiment>
FIG. 1 is a configuration diagram schematically showing a distance measuring device 1 according to a first embodiment of the present invention. FIG. 1A is a view as seen from a direction orthogonal to the optical axis of the optical system, and FIG. 1B is a view of the II plane of FIG. 1A as seen from the optical axis direction. In FIG. 1A, it is assumed that the direction is represented by XYZ orthogonal coordinates, and the target object is in the Z direction in the drawing.

  As shown in FIG. 1A, in the distance measuring device 1, optical components are arranged along an optical axis 1 extending in the Y direction and optical axes 2, 3, and 4 extending in the Z direction. A laser light source 11 that emits laser light having a wavelength in the near infrared region along the optical axis 1, a condenser lens 12 that condenses the laser light, and a dichroic prism 13 that reflects light in the near infrared region and transmits visible light. Is arranged. An anti-vibration lens 14 that operates in a direction perpendicular to the optical axis 2 and an objective lens 15 that faces a target object that is present on the left side of the drawing are disposed along the optical axis 2.

  Further, along the optical axis 3, a reticle placed at an image formation position by an erecting prism 16, an objective lens 15, and an anti-vibration lens 14 that internally reflects the light from the dichroic prism 13 a plurality of times and emits the light from a predetermined surface. 17. An eyepiece 18 for enlarging the image of the target object is disposed. Furthermore, along the optical axis 4, an objective lens 31 that faces the target object, a vibration-proof lens 32 that operates in a direction perpendicular to the optical axis 4, a narrow-band filter 33 that cuts light other than the wavelength of the near-infrared laser beam, A light receiving element 34 that generates an electrical signal by the incidence of infrared laser light is disposed.

  The laser light L1 emitted from the laser light source 11 is collected by the condenser lens 12, reflected by the reflecting surface 13A of the dichroic prism 13 in the Z direction, and transmitted to the outside through the anti-vibration lens 14 and the objective lens 15. . Here, a concave lens which is one of the divergent optical elements having negative power (refractive power) is used as the anti-vibration lens 14. The laser light source 11, the condenser lens 12, the dichroic prism 13, the anti-vibration lens 14 and the objective lens 15 constitute the transmission optical system 10.

  The reflected laser beam L2 reflected when the laser beam L1 hits the target object is incident on the light receiving element 34 through the objective lens 31, the vibration proof lens 32, and the narrow band filter 33 in order. The light receiving element 34 is arranged so that the incident surface thereof is an image forming surface formed by the objective lens 31 and the image stabilizing lens 32. Since not only the reflected laser beam L2 but also light of other wavelengths due to natural light is incident on the light receiving element 34, the S / N ratio of the reflected laser beam L2 decreases. For this reason, the narrow band filter 33 is provided to cut light other than the reflected laser light L2, thereby improving the S / N ratio of the reflected laser light L2. The objective lens 31, the anti-vibration lens 32, the narrow band filter 33, and the light receiving element 34 constitute a reception optical system 30.

  The light L3 from the target object is incident on the dichroic prism 13 through the objective lens 15 and the anti-vibration lens 14 in order. The light L3 includes reflected laser light L2 and natural light. The reflected laser beam L2 is reflected in the Y direction by the reflecting surface 13A of the dichroic prism 13 and returns to the laser light source 11. Visible light contained in the light L3 passes through the reflecting surface 13A of the dichroic prism 13 and enters the upright prism 16.

  The image by the light L3 becomes an inverted image through the objective lens 15 and the anti-vibration lens 14, but becomes an upright image inverted up and down by the erecting prism 16. This erect image is formed on the reticle 17 and observed (collimated) through the eyepiece 18. The objective lens 15, the image stabilizing lens 14, the dichroic prism 13, the reticle 17, and the eyepiece lens 18 constitute a collimating optical system 20.

  As described above, the dichroic prism 13 functions as a branching optical element that separates near-infrared light and visible light. The anti-vibration lens 14 and the objective lens 15 disposed on the target object side of the dichroic prism 13 are used in common for the transmission optical system 10 and the collimation optical system 20. In other words, the transmission optical system 10 and the collimation optical system 20 constitute a synthesis optical system 40 that shares the optical axis 2.

  In the distance measuring device 1, the time difference between the time when the laser light L1 is emitted from the laser light source 11 and the time when the reflected laser light L2 is received by the light receiving element 34 is measured, and the distance from the measurement time to the target object Is calculated. Specifically, the laser beam L1 is converted into pulsed light that oscillates several hundred times per second, and the time from the time when the pulse of the laser beam L1 is emitted to the time when the pulse of the reflected laser beam L2 is received is measured. And create a histogram. If the time showing the peak in the histogram is determined, the above time difference is obtained, and the distance to the target object is obtained. The above calculation is performed by the CPU 41 described later.

  Further, the target object can be observed simultaneously with the measurement by the collimating optical system 20. As described above, an image of the target object is formed on the reticle 17. For example, the reticle 17 may be a transmissive liquid crystal plate, and the image of the target object and the distance to the target object may be displayed on the liquid crystal screen.

  By the way, if the distance measuring device 1 is used in a state of shaking or shaking without operating the image stabilization function, the light of the transmission optical system 10, the reception optical system 30, and the collimation optical system 20 is caused by camera shake during hand-held operation, for example. The direction of the axis is inclined with respect to the direction of the target object, and it is difficult to continuously apply the laser beam to the target object. In the distance measurement, when the reflected light by the instantaneous light hitting the target object is incident on the objective lens 31, the number of pulses is so small that measurement data cannot be obtained on the light receiving element 34 with sufficient frequency for distance measurement. A distance error may occur. If there is an object with a different distance from the target object at the tip of the tilted optical axis, the reflected light from the object may be received and an incorrect distance measurement result may be output.

  On the other hand, in collimation, it is difficult to continuously capture the target object at the center of the reticle 17 of the collimation optical system 20. Usually, the collimating optical system 20 has a corresponding magnification, so that the inclination of the optical axes 2 and 3 may be enlarged, and the target object may be lost.

  The distance measuring device 1 according to the present embodiment is a low-cost device having an anti-vibration function capable of performing optical correction even when the optical axis is inclined, and performing high-precision distance measurement and stable observation. The configuration of the vibration isolation mechanism and the vibration isolation function will be described below.

  The distance measuring device 1 includes a central processing unit (CPU) 41, a drive mechanism 42 that drives the image stabilization lens 14 in a direction perpendicular to the optical axis 2, and a drive mechanism 43 that drives the image stabilization lens 32 in a direction perpendicular to the optical axis 4. Is provided. The drive mechanism 42 drives the anti-vibration lens 14 via the connection portion 44, and the drive mechanism 43 drives the anti-vibration lens 32 via the connection portion 45. As shown in FIG. 1B, the drive mechanism 42 includes a drive unit 42a that performs horizontal drive and a drive unit 42b that performs vertical drive. Similarly, the drive mechanism 43 includes a drive unit 43a that performs horizontal drive and a drive unit 43b that performs vertical drive. The anti-vibration mechanism includes a first anti-vibration mechanism having a drive mechanism 42 and a connection 44 for driving the anti-vibration lens 14, and a second anti-vibration mechanism having a drive mechanism 43 and a connection 45 for driving the anti-vibration lens 32. It can be conveniently divided into mechanisms.

  Further, the distance measuring device 1 includes an angular velocity sensor 46A that detects an angular velocity around the vertical axis (X axis), an angular velocity sensor 46B that detects an angular velocity around the horizontal axis (Y axis), and an XY of the anti-vibration lens 14. A position sensor 47 for detecting the position on the surface is provided. The angular velocity sensors 46A and 46B and the position sensor 47 are electrically connected to the CPU 41.

  The CPU 41 inputs angular velocity signals from the angular velocity sensors 46A and 46B, and calculates the tilt state (tilt speed and tilt direction) of the optical axis from the input signals. Further, the CPU 41 inputs a position signal of the position sensor 47, and calculates the current coordinates on the XY plane from the input signal. Based on these calculation results, a drive signal is sent from the CPU 41 to the drive mechanisms 42 and 43, and the displacements M1 and M2 of the anti-vibration lenses 14 and 32 are controlled. The displacements M1 and M2 are displacements in the direction perpendicular to the optical axis. In addition, since the position sensor for detecting the position on the XY plane is not provided in the image stabilizing lens 32, the position signal of the position sensor 47 is used when the coordinates of the image stabilizing lens 32 are necessary.

  FIG. 2 is a diagram schematically showing the optical system when the distance measuring device 1 according to the first embodiment is tilted. FIG. 3 is a diagram schematically showing an optical system when the distance measuring device 1 according to the first embodiment is tilted and when the image stabilization mechanism is operated. 2 and 3, the same components as those in FIG.

  First, a case where the distance measuring device 1 is not inclined will be described with reference to FIGS. This re-explains the content described with reference to FIG. 1 from an optical viewpoint. Of the optical axes 1 to 4 indicated by solid lines, the optical axis 1 is in the Y direction, and the optical axes 2 to 4 are in the Z direction (the same direction as the horizontal line H). The target object O is on the horizontal line H far left in the figure. Therefore, the optical axes 2 to 4 are parallel to the horizontal line H, and the light projected from the laser light source 11 toward the target object O always travels along the optical axes 1 and 2. Considering the target object O as a reference, light from the target object O always travels along the optical axes 1 to 4.

  The light emitted from the point Q of the laser light source 11 travels along the optical axis 1, is reflected by the reflecting surface 13 </ b> A of the dichroic prism 13, and travels toward the target object O through the anti-vibration lens 14 and the objective lens 15. The reflected laser light L2 reflected by the target object O enters the objective lens 31 of the receiving optical system 30, passes through the vibration-proof lens 32, reaches the point R of the light receiving element 34, and also enters the objective lens 15. Then, the light is reflected by the reflecting surface 13A of the dichroic prism 13 and returns to the point Q of the laser light source 11. On the other hand, the visible light included in the light L3 from the target object O passes through the objective lens 15, the anti-vibration lens 14, the dichroic prism 13, and the erecting prism 16 along the optical axis 2 and is emitted on the image plane of the target object O. The light passes through a point P on the axis 3 and exits from the eyepiece 18 to the outside.

  Next, a case where the distance measuring device 1 is tilted due to camera shake or the like and the optical axis is tilted by an angle θ will be described with reference to FIGS. Light from the target object O travels as indicated by a broken line in the figure. Regarding the transmission optical system 10, the reflected laser light L 2 included in the light L 3 incident on the objective lens 15 is reflected by the reflecting surface 13 A of the dichroic prism 13 and reaches the point Q ′ of the laser light source 11. That is, the reflected laser light L2 incident on the objective lens 15 travels along the path of the light beam A and the light beam B. Visible light incident on the objective lens 15 passes through the anti-vibration lens 14, the dichroic prism 13, and the erecting prism 16, passes through the point P ′ off the optical axis 3 on the image plane of the target object O, and passes through the eyepiece 18. Inject outside. That is, the visible light that has entered the objective lens 15 travels along the path of the light rays A and A ′.

At this time, when the angular magnification of the collimating optical system 20 is γ, the angle formed by the optical axis of the light beam A ′ emitted from the eyepiece lens 18 is expressed by Expression (1).
θ ′ = γθ (1)
That is, the light beam is deflected by the angle θ ′ as compared with the state in which the distance measuring device 1 is not inclined. Since γ is usually about 6 to 20 times, a slight angle change on the object side results in a large angle change on the eyepiece side, and a camera shake feeling is amplified.

  With respect to the receiving optical system 30, the reflected laser light L 2 from the target object O incident on the objective lens 31 travels like a light beam C because the optical axis is inclined by the angle θ, and the point R ′ on the extended surface of the light receiving element 34. And does not enter the light receiving element 34. Therefore, it is not possible to obtain distance data from the reflected laser beam L2 from the target object O. Here, if the size of the light receiving element 34 is increased, light having a large angle with respect to the optical axis 4 can also be received. However, the size of the light receiving element 34 is affected by so-called background light other than the signal light incident on the light receiving element 34 unless it is stopped to a size corresponding to the angle at which the transmitted light projected onto the target object O is viewed. This is not preferable because the S / N ratio deteriorates. That is, the size of the light receiving element 34 is limited, and from this point, a vibration isolating means is necessary.

FIG. 3 is a diagram for explaining the optical system when the image stabilization mechanism is activated. FIG. 3 shows the light beams A ″, B ″, and C ″ when the vibration isolation mechanism is activated in addition to the light beams shown in FIG. The reflected laser light L2 included in the light L3 incident on the objective lens 15 from the target object O travels as a light beam A until reaching the anti-vibration lens 14, and is corrected by the displacement Δ1 of the anti-vibration lens 14. The light path bends.
The displacement Δ1 is a movement in the direction perpendicular to the optical axis 2. The reflected laser light L 2 is further reflected by the dichroic prism 13, travels like a light beam B ″, and returns to the point Q of the laser light source 11. This means that laser light can be projected without removing the target object O even if the optical axis is inclined by an angle θ.

  Further, the visible light included in the light L3 incident on the objective lens 15 from the target object O is corrected by the displacement of the anti-vibration lens 14 and passes through the dichroic prism 13 and the erecting prism 16 like the light ray A ″. Then, it passes through the point P on the optical axis 3 on the image plane of the target object O, and exits from the eyepiece 18 to the outside. In other words, the visible light incident on the objective lens 15 travels in the order of light ray A → light ray A ″. The angle between the light beam A ″ and the optical axis 3 is close to 0 °, and an anti-vibration effect is obtained.

  With respect to the receiving optical system 30, the reflected laser light L2 from the target object O incident on the objective lens 31 is corrected by the displacement Δ2 of the image stabilizing lens 32 and the optical path is bent. The displacement Δ2 is a movement in the direction perpendicular to the optical axis 4, that is, a movement along the XY plane. The reflected laser light L2 travels like a light beam C ″ and reaches a point R near the center of the light receiving element 34. This means that the reflected laser light from the target object O surely enters the light receiving element 34 even if the optical axis is inclined by the angle θ.

  In the embodiment of the present invention, the displacement Δ1 of the image stabilizing lens 14 and the displacement Δ2 of the image stabilizing lens 32 are not equal. However, if the objective lenses 15 and 31 and the anti-vibration lenses 14 and 32 have the same focal length and the distance between the principal points of the objective lens and the anti-vibration lens is equal, when the displacements Δ1 and Δ2 are made closer, the light rays A ″ and the light rays C ″ can be centered. As a result, the parts can be shared and the cost can be reduced.

FIG. 4 is a diagram for explaining the principle of deflection of light rays by the anti-vibration lens used in the first embodiment. When the focal length of the image stabilizing lens 14 is f1, the image can be moved from P ′ to P on the image plane separated from the image stabilizing lens 14 by L by displacing the image stabilizing lens 14 by Δ1. When the moving distance from P ′ to P is s, the relationship of Expression 2 is established.
s = L · Δ1 / f1 (2)

Now, assuming that the combined focal length of the objective lens 15 and the anti-vibration lens 14 constituting the collimation optical system 20 of the distance measuring device 1 is f, an image of a light beam from the target object O when the optical axis is inclined by an angle θ. The moving distance s on the surface is expressed by Equation 3.
s = f · tan θ (3)
From Expressions 2 and 3, the displacement Δ1 of the image stabilizing lens 14 is obtained by Expression 4.
Δ1 = f · tan θ · f1 / L (4)
In Equation 4, since the amount other than the angle θ is a known amount, the amount of displacement Δ1, that is, the operation of the vibration-proof lens 14 is detected by detecting the angle θ with the angular velocity sensors 46A and 46B housed in the casing of the distance measuring device 1. The amount can be determined.

  The light beam deflection principle described above will be applied to the receiving optical system 30 of the distance measuring device 1. Unlike the collimating optical system 20, the receiving optical system 30 does not observe the image of the target object O with the eyes, so that the control of the deflection of the light beam can be made rougher than the collimating optical system 20. . In other words, the reflected laser beam L2 from the target object O is allowed to the limit where it enters the light receiving element 34. The control of the deflection of the light beam in the reception optical system 30 can be less accurate than the transmission optical system 10.

Now, assuming that the size of the light receiving element 34 is Y and the combined focal length of the objective lens 31 and the image stabilizing lens 32 constituting the receiving optical system 30 is F, when the optical axis is inclined by an angle θ, In order for the light beam to enter the light receiving element 34, the movement amount S to be corrected may be in the range represented by the inequality of equation (5). The moving amount S is a moving distance of the light beam on the incident surface of the light receiving element 34.
F · tan θ−Y / 2 ≦ S ≦ F · tan θ + Y / 2 (5)

When the focal length of the image stabilizing lens 32 is f2, the displacement amount Δ2 of the image stabilizing lens 32 may be in a range represented by the inequality of Expression 6 derived from Expression 5. Here, L is the distance from the image stabilizing lens 32 to the incident surface of the light receiving element 34 that is the image plane.
(F · tan θ−Y / 2) · f2 / L ≦ Δ2 ≦ (F · tan θ + Y / 2) · f2 / L
(6)
In this way, the image stabilization lens 32 only needs to operate within the range of Equation 6, and rough control is sufficient as compared with the collimation optical system 20 and the transmission optical system 10. Therefore, the drive mechanism 43 can reduce the operation amount as compared with the drive mechanism 42. Therefore, the movements of the anti-vibration lens 32 and the anti-vibration lens 14 are different. Therefore, the amount of the displacement M2 is smaller than that of the displacement M1, the displacement speed can be slowed, and rough control can be accurately performed.

Specifically, we will consider using numerical values.
If the anti-shake accuracy ε of the collimating optical system 20 or the transmission optical system 10 is set as an allowable value of the amount of image movement from the optical axis, and the anti-shake accuracy ε is set to be less than the limit of resolution, the F number of each optical system Is F, the anti-vibration accuracy ε is expressed as follows from the radius of the Airy disk.
ε ≦ 1.22 · λ · F (7)
As a general example, if the wavelength λ = 555 nm and F = 5, the image stabilization accuracy ε is 0.0034 mm from the equation (7).
On the other hand, if the F number of the reception optical system 30 is the same as that of the collimation optical system 20 or the transmission optical system 10, the image stabilization accuracy ε itself is the same value as above. However, the size of the light receiving element 34 is generally about 0.5 mm in diameter, and the image is allowed to move within this range, so the maximum amount of image movement is 0.25 mm. Therefore, the receiving optical system 30 has an allowable value that is about 74 times larger than that of the collimating optical system 20 or the transmitting optical system 10.

The distance measuring device 1 according to the present embodiment has the following operational effects.
(1) Since the anti-vibration lens 14 is displaced by the first anti-vibration mechanism and the anti-vibration lens 32 is displaced by the second anti-vibration mechanism, appropriate accuracy required for the optical system having each anti-vibration lens The anti-vibration lens can be driven at a speed. Specifically, the anti-vibration lens 32 of the reception optical system 30 needs rough control as compared with the anti-vibration lens 14 of the transmission optical system 10 and the collimation optical system 20.
(2) Since it is not necessary to synchronize between the first and second vibration isolation mechanisms, that is, it is not necessary to match the control amount and the control timing, the control is simple.
(3) As a result of the above, the second vibration isolation mechanism can be simplified, and the first and second vibration isolation mechanisms do not need to maintain exactly the same performance of the parts used. The allowable range is widened and the yield is improved. Also, the cost for creating the control program is reduced. Furthermore, since the first and second vibration isolation mechanisms are not operated by the same drive member, the distance measuring device 1 can be reduced in size.

<Second Embodiment>
FIG. 5 is a block diagram schematically showing the distance measuring device 2 according to the second embodiment of the present invention. FIG. 5A is a diagram seen from a direction orthogonal to the optical axis of the optical system, and FIG. 5B is a diagram seen from the II-II plane of FIG. 5A from the optical axis direction. As in FIG. 1, in FIG. 5A, it is assumed that the direction is represented by XYZ orthogonal coordinates, and the target object is in the Z direction in the figure. Also, the same components as those in FIG.

The distance measuring device 2 according to the present embodiment has the same optical system as the distance measuring device 1 according to the first embodiment (see FIG. 1). The distance measuring device 2 is structurally different from the distance measuring device 1 in the following two points.
(A) The vibration-proof lenses 14 and 32 are mechanically connected.
(B) The vibration-proof lenses 14 and 32 are driven only by the drive mechanism 48.
That is, the anti-vibration lenses 14 and 32 are mechanically connected by the connecting portion 49, and the drive mechanism 48 drives the anti-vibration lens 14 via the connecting portion 49. The image stabilization lens 32 is driven following the operation of the image stabilization lens 14. This can be said that the two anti-vibration mechanisms share one drive mechanism. Therefore, when the tilt of the optical axis occurs, the anti-vibration lenses 14 and 32 are simultaneously displaced in the same pattern. As shown in FIG. 5B, the driving mechanism 48 includes a driving unit 48a that performs horizontal driving and a driving unit 48b that performs vertical driving.

  The operation of the distance measuring device 2 configured in this way will be described. The CPU 41 inputs angular velocity signals from the angular velocity sensors 46A and 46B, and calculates the tilt state (tilt speed and tilt direction) of the optical axis from the input signals. Further, the CPU 41 inputs a position signal of the position sensor 47, and calculates the current coordinates on the XY plane of the image stabilizing lens 14 from the input signal. Based on these calculation results, a driving signal is sent from the CPU 41 to the driving mechanism 48, and the anti-vibration lenses 14 and 32 are controlled to be displaced M3 and M4, respectively. The displacements M3 and M4 are displacements in the direction perpendicular to the optical axis. As described above, since the anti-vibration lens 32 is driven following the operation of the anti-vibration lens 14, the displacement accuracy decreases due to the influence of the vibration and deflection of the connecting portion 49. However, the reflected light L2 from the target object does not reach the center of the light receiving element 34, but reaches the light receiving range, and thus distance measurement is possible. In addition, since the position sensor for detecting the position on the XY plane is not provided in the image stabilizing lens 32, the position signal of the position sensor 47 is used when the coordinates of the image stabilizing lens 32 are necessary.

  The distance measuring device 2 according to the present embodiment also has the same effects as the distance measuring device 1 according to the first embodiment. Furthermore, since only one drive mechanism is required, the cost and size of the apparatus can be further reduced.

<Third Embodiment>
FIG. 6 is a block diagram schematically showing the distance measuring device 3 according to the third embodiment of the present invention. 6A is a diagram viewed from a direction orthogonal to the optical axis of the optical system, and FIG. 6B is a diagram viewed from the III-III plane of FIG. 6A from the optical axis direction. As in FIGS. 1 and 2, in FIG. 6A, it is assumed that the direction is represented by XYZ orthogonal coordinates and the target object is in the Z direction in the figure. In addition, the same components as those in FIGS.

The distance measuring device 3 according to the present embodiment is the same as the distance measuring device 1 according to the first embodiment (see FIG. 1) except for a part of the optical system and the drive mechanism, and the other configurations. The distance measuring device 3 is structurally different from the distance measuring device 1 in the following two points.
(A) The variable apex angle prism 50 is disposed in front of the objective lens 15 in place of the image stabilizing lens 14, and the apex angle that is an angle formed by the incident surface and the exit surface of the variable apex angle prism 50 is changed by the drive mechanism 51. Let
(B) The variable apex angle prism 60 is disposed in front of the objective lens 31 instead of the image stabilizing lens 32, and the apex angle of the variable apex angle prism 60 is changed by the drive mechanism 52.
The variable apex angle prisms 50 and 60 are formed by connecting two transparent disks using bellows and filling the inside with a transparent liquid, and changing the position and angle of the apex angle over the circumference of the transparent disk. Can do. As shown in FIG. 6B, the drive mechanism 51 includes a drive unit 51a that drives the vertical angle change of the horizontal direction and a drive unit 51b that drives the vertical angle change of the vertical direction. Similarly, the drive mechanism 52 includes a drive unit 52a that performs horizontal drive and a drive unit 52b that performs vertical drive.

  In the distance measuring device 3 according to the present embodiment, when the optical axis is inclined due to camera shake or the like, the laser beam L1 emitted from the laser light source 11 is deflected by changing the apex angle of the variable apex angle prism 50. Project toward the target object. The laser light source 11, the condenser lens 12, the dichroic prism 13, the objective lens 15, and the variable apex angle prism 50 constitute a transmission optical system 10 '.

  The reflected laser beam L2 reflected when the laser beam L1 hits the target object is incident from the variable apex angle prism 60 and reaches the light receiving element 34 through the objective lens 31 and the narrow band filter 33. By changing the apex angle of the variable apex angle prism 60 in accordance with the inclination of the optical axis, the reflected laser beam L2 is reliably guided to the light receiving element 34. The variable apex angle prism 60, the objective lens 31, the narrow band filter 33, and the light receiving element 34 constitute a receiving optical system 30 '.

  The light L3 from the target object is incident on the dichroic prism 13 through the variable apex angle prism 50 and the objective lens 15. The reflected laser light L2 included in the light L3 returns to the laser light source 11. Visible light included in the light L3 passes through the reflecting surface 13A of the dichroic prism 13 and is observed (collimated) by the eyepiece 18 through the erecting prism 16 and the reticle 17. The variable apex angle prism 50, the objective lens 15, the dichroic prism 13, the reticle 17 and the eyepiece lens 18 constitute a collimating optical system 20 '.

  The variable apex angle prisms 50 and 60 are controlled such that the apex angle becomes the angle changes M5 and M6, respectively. Since the variable apex angle prism 60 is driven following the apex angle change of the variable apex angle prism 50, the angle change M6 can reduce the accuracy of the angle change compared to the angle change M5. Since the variable apex angle prism 60 is not provided with the angle sensor 55 for detecting the apex angle, the angle signal of the angle sensor 55 is used when the apex angle of the variable apex angle prism 60 is necessary.

  The distance measuring device 3 configured as described above has the same effects as the distance measuring device 1.

Various modifications can be considered for the distance measuring apparatus of the present invention.
(A) In the first to third embodiments, the erecting prism 16 is a Porro prism, but may be a roof prism if it is an erecting prism.
(B) In the first to third embodiments, the dichroic prism 13 and the erecting prism 16 are separate members. However, the dichroic prism 13 and the erecting prism 16 are integrated into an optical member having both functions. May be arranged. Thereby, the number of parts is reduced, and the distance measuring device can be further reduced in size.
(C) In the first to third embodiments, the anti-shake accuracy of the reception optical system can be lowered than the anti-shake accuracy of the transmission optical system or collimation optical system. It is also possible to make the dimensional accuracy and the optical axis adjustment accuracy lower than that of the transmission optical system or collimation optical system. Thereby, cost reduction, such as component manufacture and an assembly, can be aimed at.
(D) In the third embodiment, the variable apex angle prisms 50 and 60 change the apex angle by the drive mechanisms 51 and 52, respectively. However, the variable apex angle prisms 50 and 60 are mechanically or electrically changed. They may be connected together and driven by a single drive mechanism. Thereby, the number of parts is reduced, and the distance measuring device can be further reduced in size.

The present invention is not limited to the embodiments described above as long as the characteristics are not impaired.
In the first to third embodiments described above, the distance measuring apparatuses 1 to 3 having the collimation optical system and capable of both the distance measurement to the target object and the collimation of the target object have been described. A distance measuring device that does not have a quasi-optical system and performs only distance measurement using a transmission optical system and a reception optical system is also included in the present invention. The present invention also includes a transmission optical system that projects signal light toward a target object, and a reception optical system that receives reflected light reflected from the target object by a light receiving element, and reflects the reflected light from the projection of the signal light. In the distance measuring apparatus that measures the distance to the target object based on the time until the light is received, the transmission optical system performs a first anti-vibration operation for deflecting the light beam according to the change in the direction of the optical axis with respect to the target object. It can also be said to be a distance measuring device that is provided with an anti-vibration mechanism, and in which a second anti-vibration mechanism that performs an operation different from the operation of the first anti-vibration mechanism is provided in the reception optical system.

1 is a configuration diagram schematically showing a distance measuring apparatus according to a first embodiment of the present invention. FIG. 1A is a view as seen from a direction orthogonal to the optical axis of the optical system, and FIG. 1B is a view of the II plane of FIG. 1A as seen from the optical axis direction. It is a figure which shows typically an optical system when the ranging apparatus which concerns on 1st Embodiment inclines. It is a figure which shows typically an optical system when the distance measuring device by 1st Embodiment inclines and the vibration isolating mechanism act | operates. It is a figure explaining the deflection | deviation principle of the light ray by the vibration proof lens used in 1st Embodiment. It is a block diagram which shows typically the ranging apparatus which concerns on the 2nd Embodiment of this invention. FIG. 5A is a diagram seen from a direction orthogonal to the optical axis of the optical system, and FIG. 5B is a diagram seen from the II-II plane of FIG. 5A from the optical axis direction. It is a block diagram which shows typically the ranging apparatus which concerns on the 3rd Embodiment of this invention. 6A is a diagram viewed from a direction orthogonal to the optical axis of the optical system, and FIG. 6B is a diagram viewed from the III-III plane of FIG. 6A from the optical axis direction.

Explanation of symbols

1-3: Distance measuring device 10: Transmission optical system 11: Laser light source 13: Dichroic prism 14: Anti-vibration lens 16: Erecting prism 17: Reticle 20: Collimation optical system 30: Reception optical system 32: Anti-vibration lens 34 : Light receiving element 40: Synthetic optical system 41: CPU 42, 43, 48, 51, 52: Drive mechanism 49: Connecting part 50, 60: Variable apex angle prism

Claims (7)

A transmission optical system that projects signal light toward a target object;
A receiving optical system that receives the reflected light reflected by the target object by a light receiving element;
In the distance measuring apparatus that measures the distance to the target object based on the time from the projection of the signal light to the reception of the reflected light,
The transmission optical system is provided with a first anti-vibration mechanism that performs an anti-vibration operation for deflecting light according to a change in the direction of the optical axis with respect to the target object,
2. A distance measuring device, wherein the receiving optical system is provided with a second anti-vibration mechanism that performs an anti-vibration operation with lower accuracy than the first anti-vibration mechanism. The distance measuring device according to claim 1,
The distance measuring device is characterized in that the second vibration isolation mechanism operates by allowing a decrease in accuracy to a range where the light receiving element can receive the reflected light. The distance measuring device according to claim 1 or 2,
A collimating optical system for collimating the target object;
The collimating optical system and the transmission optical system constitute a combining optical system that shares a part of the optical axis on the target object side of the branching optical element that separates the two optical systems,
A distance measuring device comprising the first vibration isolation mechanism in the synthetic optical system. The distance measuring device according to any one of claims 1 to 3,
The first vibration isolation mechanism has a first drive mechanism for driving a first optical element disposed in the transmission optical system,
The distance measuring device, wherein the second vibration isolation mechanism has a second drive mechanism for driving a second optical element disposed on an optical path of the reception optical system. The distance measuring device according to any one of claims 1 to 3,
Mechanically connecting the first optical element disposed in the transmission optical system and the second optical element disposed in the reception optical system;
The first vibration isolation mechanism drives the first optical element,
The distance measuring device, wherein the second vibration isolation mechanism is mechanically coupled to the first vibration isolation mechanism to drive the second optical element. The distance measuring device according to claim 4 or 5,
The distance measuring apparatus, wherein the first and second optical elements are optical elements that are displaced in a direction perpendicular to the optical axis when driven. The distance measuring device according to claim 4 or 5,
The distance measuring device, wherein the first and second optical elements are variable apex angle prisms that change an apex angle, which is an angle formed by an incident surface and an exit surface, by driving.

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