JP2002131606A - Mounting device for lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve accuracy of photographing or measuring by improving positioning accuracy of a lens for the replacement of a lens and eliminating deviation in a position between the lens and an image pickup surface. SOLUTION: In the mounting device with which the lens 411 is detachably mounted on a device body 401, at least two pins 496a and 496b and holes 416a and 416b in which each pin is fitted are provided at the device body 401 or the lens 411, and elastic members 414a and 414b to press the pin fitted in the hole to the inner peripheral surface of the hole in one direction are provided in the periphery of the hole, and each pin is fitted in each hole and abuts on one point of the inner peripheral surface of each hole, so that the positioning of the lens in a radial direction is performed. The pin is pressed in the radial direction of the lens by one elastic member 414a, and the pin is pressed in a direction along a peripheral direction of the lens by the other elastic member 414b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens attaching device for detachably attaching a lens used for a camera or various measuring devices to a main body. For example, it is used as a lens mounting device of a three-dimensional measurement device that irradiates an object with light such as slit light and measures the shape of the object in a non-contact manner.

[0002]

2. Description of the Related Art A non-contact type three-dimensional measuring device called a range finder or the like can perform higher-speed measurement than a contact-type three-dimensional measuring device. Therefore, data input to a CG system or a CAD system, body measurement, It is used for visual recognition of robots.

[0003] Among the rangefinders, there is a method of irradiating a specific detection light to an object, receiving reflected light thereof, and performing measurement based on triangulation. In this method, the glow generated by projecting a light source such as a semiconductor laser onto a target (object) is captured by a camera from different angles, and a triangle is formed by connecting the light source, the camera, and the position of the glow, and a three-dimensional position is obtained.

[0004] As this method, a spot light projection method in which a spot light is projected to optically two-dimensionally scan an object to obtain a three-dimensional image of the object, and a slit light is projected to optically scan the object by one-dimensionally. 2. Description of the Related Art A slit light projection method (also referred to as a light cutting method) that performs dimensional scanning is known. In the spot light projection method, a spot image having a point-like cross section is obtained on the light receiving surface, and in the slit light projection method, a slit image having a linear cross section is obtained. The three-dimensional image is a set of pixels indicating the three-dimensional positions of a plurality of parts on the object.

FIG. 18 is a diagram showing the outline of the slit light projection method, and FIG. 19 is a diagram for explaining the principle of measurement by the slit light projection method. An object Q to be measured is irradiated with a band-shaped measurement slit light U having a narrow cross section, and the reflected light is incident on, for example, an imaging surface S of a two-dimensional light receiving element [FIG.
(A)]. If the irradiated portion of the object Q is flat, the captured image (slit image) becomes a straight line (FIG. 18B). If the irradiated portion has irregularities, the straight line may be bent or stepped (FIG. 18C). That is, the magnitude of the distance between the measuring device and the object Q is reflected on the incident position of the reflected light on the imaging surface S (FIG. 18D). By deflecting the measurement slit light U in the width direction, a three-dimensional position can be sampled by scanning the object surface in a range visible from the light receiving side. The number of sampling points depends on the number of pixels of the image sensor.

In FIG. 19, the light projecting system and the light receiving system are arranged such that the base line AS connecting the starting point A of light projection and the imaging surface S of the light receiving system is perpendicular to the light receiving axis. The light receiving axis is perpendicular to the imaging surface S, and the intersection S between the light receiving axis and the imaging surface S
0 is the origin of the three-dimensional rectangular coordinate system. The light receiving axis is the Z axis, the base line AS is the Y axis, and the length direction of the slit light is the X axis.

[0007] The distance between the principal points between the front principal point H and the rear principal point H 'of the light receiving lens is HH', and the distance from the point S0 to the rear principal point H 'of the light receiving lens is b. Note that the distance b is a so-called image distance, and an image of a finite object is captured on the imaging surface S.
Is the distance from the rear principal point H ′ of the lens to the imaging surface S when an image is formed on the imaging surface S. The image distance b is determined by the relationship between the focal length of the light receiving lens and the amount of lens extension for focus adjustment.

The measurement slit light U is applied to a point P (X,
(Y, Z), the angle between the light projecting axis and the light projecting reference plane (light projecting plane parallel to the light receiving axis) is defined as the light projecting angle θa, and a straight line connecting the point P and the front principal point H is received. Assuming that an angle formed with a plane including the axes (light receiving axis plane) is a light receiving angle θp, the coordinates Z of the point P
Is represented by the following equation.

L = L1 + L2 = Ztan θa + (Z−HH′−b) tan θp Z = {L + (HH ′ + b) tan θp} / Δtanθ
a + tan θp｝ The light receiving position of the point P is defined as P ′ (xp, yp, 0) [FIG.
(See (a)], if the imaging magnification of the light receiving lens is β, the coordinates X and Y of the point P are as follows: X = xp / β Y = yp / β In the above equation, the base line length L is determined by the arrangement of the light projecting system and the light receiving system, and is a known value in advance. The light receiving angle θp can be calculated from the relationship tan θp = b / yp. The imaging magnification β of the light receiving lens is β = −b / (Z−H
H′-b) can be calculated.

That is, if the distance HH 'between principal points, the image distance b, and the projection angle θa are known by some means, the position P' (xp, yp) on the imaging surface S is measured, and The three-dimensional position of P can be determined. The distance HH 'between the front principal point and the rear principal point, and the image distance b are determined by the relative positional relationship of the lens groups constituting the light receiving system.

In a three-dimensional measuring apparatus in which the light-receiving lens system is of a fixed-focus fixed type, that is, only when the light-receiving lens and the object have a predetermined distance relationship, the distance between the lens group and the imaging surface S is always constant. Since the distance is constant, the distance HH ′ between the front principal point and the rear principal point and the image distance b can be input as fixed values in advance.

On the other hand, in a three-dimensional measuring apparatus in which the distance relationship between the light receiving system and the object is variable, it is necessary to move some or all of the lens groups constituting the light receiving system along the light receiving axis for focusing. . Further, the three-dimensional measuring device capable of variably setting the angle of view of the light receiving system has a zoom mechanism that changes the focal length of the lens by moving a part or all of the lens group along the light receiving axis.

In these cases, a relative position of the lens group is determined by providing a potentiometer (position sensor) for knowing the position of the lens group, and by providing an encoder associated with the motor in automatic lens driving using a motor. The distance HH 'between the front principal point and the rear principal point and the image distance b can be obtained from the table which is known and stored in advance.

The projection angle θa is determined by the deflection angle of the measurement slit light U. In a three-dimensional measuring apparatus using a galvanomirror as a deflecting unit, the deflection angle of the measurement slit light U at the time of imaging is recognized by synchronously controlling the imaging timing of the light receiving element, the rotation start angle of the galvanomirror, and the rotational angular velocity. , A method of calculating the projection angle θa is known.

At the time of three-dimensional measurement based on the above principle, a user who is a measurer determines the position and orientation of the three-dimensional measuring device, and changes the angle of view of the light receiving lens as necessary to change the imaging range (scanning range) of the object Q. ) Is set.

The angle of view can be changed by using a zoom lens as the light receiving lens or by replacing the lens with a lens having a different focal length. In facilitating the framing operation, a monitor image obtained by photographing the object Q at the same angle of view as the scanning range is useful.

Now, for example, in three-dimensional CG (three-dimensional computer graphics), two-dimensional image data indicating color information of the object Q is required in addition to three-dimensional data indicating the shape of the object Q in many cases.

In order to acquire both the three-dimensional data and the two-dimensional image data, see Japanese Patent Application Laid-Open No. 9-196632.
No. 2 proposes a method of performing color separation into a plurality of optical paths using a beam splitter in a receiving optical system.

[0019]

In a three-dimensional measuring apparatus for performing measurement based on such a principle, the measurement accuracy of the position P '(xp, yp) on the imaging surface S is important.

Generally, a zoom lens has a large distortion as compared with a single focus lens.
The position of (xp, yp) is shifted. Even if the deviation is compensated for by the correction, the deviation does not become sufficiently small.

When the resolution of the light receiving lens is low,
The captured image on the imaging surface S lacks sharpness, and the position P ′ (x
The measurement accuracy of (p, yp) decreases. It is difficult to improve the resolution of a zoom lens, and in that case, the number of lenses increases, the weight and size increase, and the price increases.

Therefore, it is conceivable that a plurality of single focus lenses having different angles of view are prepared as light receiving lenses, and the light receiving lenses are replaced and used according to an object. In that case,
The reproducibility of the device for mounting the light receiving lens when the light receiving lens is replaced is important.

That is, when the displacement of the light receiving lens causes a displacement of ΔX in the lens radial direction, the positional relationship between the light receiving lens and the imaging surface S is also displaced by ΔX. Will happen.

In addition, when a displacement of ΔZ occurs in the lens axis direction, an error occurs in the detection of the position of the lens group of the light receiving lens (the amount of focus extension). Gets worse.

For example, in the case of a lens replacement system using a bayonet type mount often used in a single-lens reflex camera, a displacement of up to about 0.04 mm occurs in the lens radial direction due to the lens replacement. In such a lens exchange method, sufficient measurement accuracy in three-dimensional measurement cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and improves the positioning accuracy of a lens by exchanging a light receiving lens and the like, and reduces the positional displacement between the lens and an imaging surface to improve the accuracy of photographing or measurement. The purpose is to improve.

[0027]

A lens mounting apparatus according to the present invention is a mounting apparatus for removably mounting a lens on a main body.
A pin and a hole into which the pin fits are provided, and an elastic member is provided around the hole to press the pin into the hole in one direction on the inner peripheral surface of the hole, and the pin is inserted into the hole. The lens is configured to be positioned in the radial direction or the circumferential direction by being fitted and abutting on one position on the inner peripheral surface of the hole.

Preferably, an abutting surface is provided on the flange portion of the main body and the lens for abutting and positioning in the axial direction with each other. A screw ring is provided for pressing and fixing the contact surfaces of the main body and the flange portion of the lens to each other, the direction in which the elastic member presses the pin against the inner peripheral surface of the hole, and the screw of the screw ring is tightened. It almost matches the direction.

Further, at least two pins and a hole into which each pin fits are provided in the main body or the lens, and
The elastic member provided in one hole presses the pin in a direction along the radial direction of the lens, and the elastic member provided in another hole presses the pin in a direction along the circumferential direction of the lens. So that each is arranged.

According to another aspect of the present invention, there is provided an attachment device for detachably attaching a lens to a main body, wherein the main body has a fixed frame, and is movable in an axial direction by a screw with respect to the fixed frame. A rotating ring is provided, and the rotating ring or the lens detachably provided on the rotating ring is provided with a pin and a hole into which the pin is fitted, and around the hole, the pin fitted into the hole is provided. An elastic member for pressing the inner peripheral surface of the hole in one direction is provided, and the elastic member is arranged so as to press the pin in a direction along a radial direction or a circumferential direction of the lens. And one of the inner peripheral surfaces of each hole
It is configured such that the lens is positioned in the radial direction or the circumferential direction by abutting the portion.

Preferably, a regulating member is provided in front of the lens so as to be detachably attached to the main body, and the fixed frame is provided with a rotation lock mechanism for regulating rotation of the rotating ring. The lock mechanism is configured such that when the restricting member is removed, a lock pin urged by an elastic member engages a lock hole, and when the restricting member is attached, the restricting member is Is configured to move the lock pin against the urging force to release the engagement with the lock hole.

The lens is provided with a detection blade, and the fixed frame is provided with a sensor for detecting the detection blade with the rotation of the lens.

In the present invention, the "lens" includes a lens device including a lens or a plurality of lenses, a housing for holding the lenses, and other accessories. The elastic member presses the pin in a direction along the radial direction or the circumferential direction of the lens. However, the directions need not be accurate, and it is sufficient if the pin is pressed in such a direction. The direction in which the elastic member presses the pin against the inner peripheral surface of the hole is
It is sufficient that the direction of rotation of the screw of the screw ring substantially coincides with the direction in which the screw of the screw ring is tightened. What is necessary is just to add in the direction pressed against a surface.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Overall Configuration] FIG. 1 is a configuration diagram of a measurement system 1 according to the present invention.

The measurement system 1 includes a three-dimensional camera 2 for performing three-dimensional measurement by a slit light projection method, and a three-dimensional camera 2
And a host 3 for processing the output data. The three-dimensional camera 2 performs measurement and two-dimensional image (two-dimensional image data) indicating color information of the object Q together with measurement data (slit image data) for specifying the three-dimensional positions of a plurality of sampling points on the object Q. Output the required data. The host 3 is in charge of calculating the coordinates of the sampling points using the triangulation method.

The host 3 includes a CPU 3a, a display 3
b, a keyboard 3c, a mouse 3d, and the like. Software for processing measurement data is incorporated in the CPU 3a.
Between the host 3 and the three-dimensional camera 2, both online and offline data transfer by the portable recording medium 4 is possible. As the recording medium 4, a magneto-optical disk (MO), a mini disk (MD),
There are memory cards and the like. [Configuration of Three-Dimensional Camera] FIG. FIG. 2A is a perspective view, and FIG. 2B is a plan view of an operation panel provided on a back surface.

A light projecting window 5a and a light receiving window 5b are provided on the front surface of the housing 5. The measurement slit light (band-shaped laser beam having a predetermined width w) U emitted from the internal optical unit OU travels toward the measurement target object (subject) Q through the light projecting window 5a.

A part of the measurement slit light (measurement light) U reflected on the surface of the object Q enters the optical unit OU through the light receiving window 5b. On the upper surface of the housing 5, focusing switching buttons 8a and 8b, manual focusing buttons 9a and 9b, and a release button 10 are provided. As shown in FIG. 2B, the liquid crystal display 6, the cursor button 12, the select button 13, the record button 14, the analog output terminals 15, 16, the digital output terminal 17, and the An attachment / detachment port 18 is provided. The record button 14 also functions as a focusing lock button.

The liquid crystal display 6 is used as an operation screen display means and an electronic finder. The user who is the measurer can set the shooting mode by using the buttons 12 and 13 on the back. Analog output terminal 15
Outputs measurement data, and the analog output terminal 16 outputs a two-dimensional image signal in, for example, the NTSC format. The digital output terminal 17 is, for example, a SCSI terminal. [Control Circuit] FIG. 3 is a block diagram showing a functional configuration of the three-dimensional camera 2. As shown in FIG. Solid arrows in the drawing indicate the flow of electric signals, and broken arrows indicate the flow of light.

The three-dimensional camera 2 includes the above-described optical unit O
It has a light projecting optical system 20 and a light receiving optical system 40 constituting U. In the light projecting optical system 20, a semiconductor laser (L
D) A laser beam having a wavelength (690 nm) emitted by 21 passes through the light projecting lens system 22 to become measurement slit light U, and is deflected by a galvano mirror 23 used as a scanning unit in a direction orthogonal to the slit length direction. Is done. The driver 24 of the semiconductor laser 21, the driving system 25 of the light projecting lens system 22, and the driving system 26 of the galvanomirror 23 are controlled by a system controller 52.

In the light receiving optical system 40, the light receiving lens system 4
The light condensed by 1 enters the light receiving element 43. The light receiving element 43 is a CCD area sensor. A plurality of lenses having different angles of view (focal lengths) are prepared as the light receiving lens system 41, and the user can replace and mount the light receiving lens system 41 with a desired angle of view. The lens detector 44 detects the lens type Lk and the like of the attached light receiving lens system 41 and outputs a signal to the system controller 52. Details will be described later.

The lens controller 51 and the photographing controller 50 control a photographing operation in accordance with an instruction from the system controller 52. Focusing drive
Lens controller 51 and focusing drive system 4
7 is realized. The drive system 47 is controlled by the lens controller 51.

The filter exchanger 42 is provided with the semiconductor laser 2
A total of four filters of a band-pass filter, a red transmission filter, a green transmission filter, and a blue transmission filter that transmit light in the 1,31 oscillation wavelength bands are provided.

The driving system 46 controls the filter changer 42
Is driven, and positioning is performed with any of the four filters inserted in the optical path of the light receiving lens system 41. Drive system 4
6 is controlled by the photographing controller 50.

The photographing controller 50 controls the driver 45 in synchronization with the control of the filter exchanger 42. The imaging information when the light passes through the band-pass filter and enters the light receiving element 43 is transferred to the output processing circuit 53, and the output processing circuit 53 generates measurement data Ds corresponding to each pixel of the light receiving element 43, and outputs the data. It is temporarily stored in a memory in the processing circuit 53.

The photographing information that has passed through the red transmission filter, the green transmission filter, or the blue transmission filter and entered the light receiving element 43 is stored in the red image processing circuit 5.
4. Green image processing circuit 55 or blue image processing circuit 5
After the transfer, the image is synthesized by the color processing circuit 57 and color-processed.

The imaging information subjected to the color processing is NTSC
The data is output online via the conversion circuit 58 and the analog output terminal 16 or is quantized by the digital image generation unit 60 and stored in the color image memory 61.

The output processing circuit 53 generates distance image data Dd indicating the measurement result based on the measurement data Ds, and outputs it to the multiplexer 62. The multiplexer 62
In accordance with an instruction from the system controller 52, one of two inputs of the distance image data Dd and the color image data Dc from the color image memory 61 is selected as an output.

The data selected by the multiplexer 62 is transferred to the character generator 64 via the D / A converter 63 as an analog monitor display signal.
The character generator 64 combines the image indicated by the monitor display signal with the character or symbol designated by the system controller 52, and outputs the combined image to the liquid crystal display 6.

When the user operates the record button 14 to instruct data output (recording), the measurement data Ds in the output processing circuit 53 is transmitted to the SCSI controller 59 or NT.
The data is output online in a predetermined format by the SC conversion circuit 65 or stored in the recording medium 4. Measurement data D
The analog output terminal 15 or the digital output terminal 17 is used for online output of s. Further, the color image data Dc is transferred from the color image memory 61 to the SCSI controller 59, output online from the digital output terminal 17, or stored in the recording medium 4 in association with the measurement data Ds.

The color image is used as reference information at the time of application processing on the host 3 side. The processing using color information includes, for example, processing of generating a three-dimensional shape model by combining a plurality of sets of measurement data having different camera viewpoints, and processing of thinning out unnecessary vertices of the three-dimensional shape model.

The system controller 52 includes a buzzer 66
To generate an operation confirmation sound or a warning sound. Further, a scale value sc for monitor display is given to the output processing circuit 53. The output processing circuit 53 sends to the system controller 52 three types of warning signals S described later.
11 to 13 and light receiving data Dg which is a part of the measurement data Ds. [Light Projection Optical System] FIG. 4 is a schematic diagram showing the configuration of the light projection optical system 20. FIG. 4A is a front view, and FIG. 4B is a side view.

The light projecting lens system 22 includes a collimator lens group 221 composed of four spherical lenses, a variator lens group 222 composed of cylindrical lenses having power only in the direction of the slit width w of the laser beam, and It is composed of three lens groups of an expander lens group 223 composed of three cylindrical lenses having power only in the length direction M of the slit.

The laser beam emitted from the semiconductor laser 21 is subjected to an optical process for obtaining an appropriate measurement slit light U in the following order. First, the beam is made substantially parallel by the collimator lens group 221. Next, the variator lens group 222 adjusts the slit width w of the laser beam. Finally, the expander lens group 22
3, the beam is expanded in the slit length direction M.

The variator lens group 222 provides the light receiving element 43 with a measuring slit light having a width of three or more pixels (in this embodiment, five pixels) regardless of the photographing distance and the angle of view of the photographing optical system 40. It is provided to make U incident. The drive system 25 moves the variator lens group 222 so as to keep the width w of the measurement slit light U on the light receiving element 43 constant according to an instruction from the system controller 52.

By increasing the length of the slit before the deflection by the scanning system 23, the distortion of the measurement slit light U can be reduced as compared with the case where the deflection is performed after the deflection. By arranging the expander lens group 223 at the last stage of the light projecting lens system 22, that is, by bringing it closer to the galvanometer mirror 23, the size of the galvanometer mirror 23 can be reduced. [Receiving Optical System] FIG. 5 schematically shows the configuration of the receiving optical system 40, FIG. 6 is an end view showing the configuration of the receiving lens system 41 and the lens mounting portion 49 when not mounted, and FIG. FIG. 8 is a front view of the light receiving lens 411, FIG. 9 is an enlarged view of a flange portion 411a of the light receiving lens 411, and FIG.
10 is an enlarged view of a part of FIG. 7, FIG. 11 is a view showing an example of the shape of the detection blade 417, and FIG. 12 is a view showing an example of a detection signal of the sensor.

In FIG. 5, the light receiving optical system 40 includes a light receiving lens system 41, a lens mounting section 49, a lens detector 44,
It comprises a filter exchanger 42, a light receiving element 43, and a lens hood LF.

The light receiving lens system 41 includes a lens mounting portion 49
Can be attached to and detached from. A plurality of light receiving lens systems 41 having different angles of view are prepared, and the light receiving lens systems 41 can be exchanged according to an object.

6 to 10, the light receiving lens system 41
Comprises a light receiving lens 411, an infrared cut filter 412, a screw ring 413, O-rings 414a and 414b, mounting screws 415a and 415b, and the like.

In this embodiment, the light receiving lens 411 is a single focus lens combining seven lenses. Holes 416a and 416b for positioning are provided in the flange portion 411a of the light receiving lens 411. One hole 416
a is for positioning the light receiving lens 411 in the radial direction, and the other hole 416 b is for positioning the light receiving lens 41.
1 for positioning in the circumferential direction. One hole 416a is formed to have a larger diameter than the other hole 416b, so that pins 496a and 496b, which will be described later, are not inserted reversely.

The O-rings 414a and 414b are made of an elastic material such as nitrile rubber and are arranged so as to partially overlap these holes 416a and 416b.
It is mounted by mounting screws 415a and 415b.

That is, as is well shown in FIG. 9, the mounting screw 415a is provided with a screw at the distal end side, and a cylindrical portion ET having a larger diameter at the root side than at the distal end side. O
The inner diameter of the ring 414a is larger than the outer diameter of the cylindrical surface ET, and the outer diameter is smaller than the axial length of the cylindrical surface ET. A part of the outer peripheral surface of the O-ring 414a protrudes toward the hole 416a.

In this state, a pin 496a to be described later is
When the pin 496a is inserted into the O-ring 41,
4a is pushed radially outward by the elasticity of the pin 496a.
Is in contact with one portion of the inner peripheral surface of the hole 416a.

The lens mounting portion 49 includes a fixed ring 491 and a rotating ring 492. The fixed ring 491 is provided fixed to the bracket 401. Rotating ring 492
Can be screwed to the fixed ring 491 by a helicoid screw 493 and can be rotated. The rotating ring 492 moves in the axial direction by rotating. The bracket 40
The bracket 1 and the bracket 401a are connected to each other and integrated.

The rotating ring 492 has an annular flange portion 494.
Having. A gear is provided on the outer peripheral surface of the flange portion 494 and meshes with a gear 472 provided on a shaft of a motor 471 of the focusing drive system 47. As the motor 471,
For example, a pulse motor is used. The rotation of the motor 471 rotates the flange portion 494, that is, the rotating ring 492, and moves in the axial direction by the helicoid screw 493.
Thus, focusing of the light receiving lens 411 is performed.

The protruding ring 495 is provided on the flange portion 494.
A male screw 495 a is provided concentrically with the helicoid screw 493 on the outer peripheral surface of the protruding ring 495. A female screw provided on the projecting ring 413a of the screw ring 413 is screwed into the male screw 495a. Therefore, by rotating the screw ring 413 and tightening the screw, the flange 411a can be fixed between the screw ring 413 and the flange 494 with the flange 411a interposed therebetween.

The flange portion 494 and the flange portion 41
The surface that comes into contact with 1a, that is, the contact surface, is finished with high accuracy, and the light-receiving lens 411 is accurately positioned in the axial direction by these contacts.

The flange portion 494 has two pins 496
a, 496b. One pin 496a fits into the hole 416a, and the other pin 496b fits into the other hole 416.
16b. The tips of the pins 496a and 496b are formed in a round shape so that the fitting can be performed smoothly. The fitted state of the pins 496a, 496b and the holes 416a, 416b is such that it has a clearance that allows easy insertion and removal.

Then, due to the elasticity of the O-rings 414a and 414b, one of the pins 496a is pushed outward in the radial direction, and the other pin 496b is pushed in the circumferential direction.
The outer peripheral surfaces of 6a and 496b abut at one point on the inner peripheral surfaces of holes 416a and 416b, respectively. Thereby, the light receiving lens 411 is accurately positioned in the radial direction.

Further, by mounting the light receiving lens system 41 using the screw ring 413, the flange portion 411a is provided.
Can be tightened with even force without distortion. Coupled with the fact that the contact surface is finished with high precision, the light receiving lens 411 is accurately positioned in the axial direction. Also, since the screw ring 413 can be rotated by hand,
No tools are required, and no excessive force is applied.

When the screw ring 413 is tightened, that is, when the screw ring 413 is rotated in the direction of the arrow M1 in FIG. 8, the flange portion 411a slidingly contacting the screw ring 413 also tries to rotate in the same direction. At that time,
Since the pin 496b is fixed, the inner circumference of the hole 416b is pressed against the pin 496b. The position pressed at that time is the same as the position pressed by the O-ring 414b. That is, the direction in which the O-ring 414b presses the pin 496b against the inner peripheral surface of the hole 416b matches the direction in which the screw of the screw ring 413 is tightened.

Now, the helicoid screw 49 of the fixed ring 491
Since the screw 3 and the screw of the screw ring 413 are provided concentrically, when the screw ring 413 is rotated, the light receiving lens 411 may rotate together with the screw ring 413 as it is. Therefore, a rotation lock mechanism LM is provided so that the light receiving lens 411 does not rotate.

The rotation lock mechanism LM includes a slider 501,
It comprises a compression spring 502 and a sensor 505. The slider 501 is movable by the shaft pins 503a and 503b on both sides sliding in holes in the holes provided in the brackets 401 and 401a in the axial direction. The shaft pin 50
3a and 503b can slide but cannot rotate. The compression spring 502 urges the slider 501 leftward in FIG. Therefore, in the free state, as shown in FIG. 6, the shaft pin 503a is in a state of protruding forward from the surface of the bracket 401a.

The slider 501 is provided with a lock pin 504. When the slider 501 is in a free state, the lock pin 504 fits into and engages with a lock hole 494a provided in the flange portion 494. Therefore, in this state, the flange portion 494 cannot rotate.

Therefore, at this time, the screw ring 41
Even if 3 is rotated, the light receiving lens 411 does not rotate. That is, the light receiving lens system 41 can be easily attached and detached by tightening and loosening the screw ring 413.

In the state locked by the lock pin 504, the bracket 401 is provided on the front surface of the light receiving lens system 41.
a when the lens hood LF is attached to the lens hood L
The shaft pin 503a is pushed by F, and the slider 501 moves rightward in FIG. Then, the lock pin 504 comes out of the lock hole 494a, and the lock is released. In this state, the motor 4
The rotation of the flange 71 rotates the flange portion 494 to perform focusing of the light receiving lens 411.

Note that the lock hole 494a is
At a predetermined radial position of 94, a plurality of them are provided along the circumferential direction. For example, they are provided every 30 degrees. This allows the lock pin 504 to fit into the lock hole 494a while the flange portion 494 rotates up to 30 degrees. Note that the lock hole 494a may be a notch, a recess, or the like, instead of a hole. It may be slit-shaped.

The sensor 505 is, for example, a transmission type or reflection type photo sensor, and detects whether the rotation lock mechanism LM is in a locked state or a released state. For example, based on the detection signal of the sensor 505, when the motor is in the locked state, the motor 471 is stopped, and the control is performed so that the measurement is not performed. In addition, the fact that the lens hood LF has come off is displayed on the display surface. When in the release state, control is performed so that a normal operation is performed.

The lens hood LF includes a central cylindrical portion LFa, an annular flat plate portion LFb provided in front of the cylindrical portion LFa and provided with a light receiving window 5b in the center, and a rear portion of the cylindrical portion LFa. It is provided with an annular flange LFc provided.

The lens hood LF protects the light-receiving lens system 41 from the outside and also functions as a safety cover for preventing the user from accidentally touching the hand while the light-receiving lens system 41 is rotating. Locking and unlocking of the flange portion 494 are automatically switched according to attachment and detachment of the lens hood LF. The lens hood LF corresponds to the regulating member of the present invention.

Next, the detection blade 417 has a ring shape with an L-shaped cross section, is attached to the outer periphery of the light receiving lens 411, and rotates with the rotation of the light receiving lens 411.
As shown in FIG. 11, the detection blade 417 is provided with notches 417a, 417b, and 417c in the circumferential direction.
The detection signal corresponding to .about.c is output from the lens detector 44.

As shown in FIG. 12, the detection signal has a pulse waveform corresponding to the notches 417a to 417c. A specific point of the detection signal, for example, the first rising point of the pulse waveform is set as the origin in focusing of the light receiving lens system 41.

The number and width of the notches 417a to 417c
By setting the mutual interval and the like in advance in accordance with the specifications of the type of the light receiving lens system 41, the F-number, the focal length, and the like, these can be specified by the detection signal of the lens detector 44.

For example, three light receiving lens systems 41 having different angles of view are prepared, and the numbers, widths, and the like of the notches 417a to 417c of the respective detection blades 417 are made different. For example, the number of the cutout portions 417 a to 417 c is set to three, two, one, or the like according to the light receiving lens system 41. When the light receiving lens system 41 is replaced and when the power of the measurement system 1 is turned on, the light receiving lens 411 is rotated, and the light receiving lens 41 is detected based on the detection signal of the lens detector 44.
One type, specification, origin position, and the like can be automatically and easily detected.

Next, a procedure for replacing the light receiving lens system 41 will be described. In the state shown in FIG. 7, the user removes the lens hood LF. Thus, the rotation of the flange portion 494 is locked by the rotation lock mechanism LM. The driving of the motor 471 is also stopped. Screw ring 41
Rotate 3 in the loosening direction and remove it.
Remove.

Then, a new light receiving lens system 41 is mounted. At this time, the pins 496a, 496b are inserted into the holes 416a,
416b. Due to the elasticity of the O-rings 414a, 414b, the pins 496a, 496b and the holes 416a, 4
The inner peripheral surface 16b abuts at one point, and high positioning accuracy in the radial direction is obtained. The light receiving lens system 41 is fixed by rotating the screw ring 413 in the tightening direction. By the contact between the flange portion 494 and the flange portion 411a, the light receiving lens 411 is accurately positioned in the axial direction.

Therefore, even if the light receiving lens system 41 is replaced, the positioning is always performed with high accuracy. That is, when one and the same light receiving lens system 41 is attached to the lens attachment part 49, it is always attached at the same position, and there is no variation. Therefore, there is no displacement between the light receiving lens system 41 and the imaging surface S of the light receiving element 43, and high-accuracy measurement can be performed.

Incidentally, for each manufactured light receiving lens system 41,
The image pickup position on the image pickup surface S of the light receiving element 43 when attached to the lens attachment unit 49 is checked, data for correction or calibration is obtained, and the data is stored in an internal memory. Thereby, when the same light receiving lens system 41 is attached thereafter, the imaging position on the imaging surface S is corrected using the data, and the measurement is performed with high accuracy.

As described above, the light receiving lens system 41 is replaceable. Therefore, depending on the size, shape, distance, brightness, or the like of the object Q, it is possible to use an appropriate light receiving lens system 41 corresponding thereto.

FIG. 13 is a perspective view showing the filter exchanger 42. As shown in FIG. The filter exchanger 42 includes a filter plate 421, a motor 422, a bandpass filter 423, a red transmission filter 424, a green transmission filter 425, and a blue transmission filter 426.

The filter plate 421 is formed in a disc shape from, for example, an aluminum alloy or a synthetic resin.
It is attached so as to be rotatable around its central rotation shaft 427. The filter plate 421 is provided with four through holes at different rotation angle positions around the rotation shaft 427, here at every 90 degrees, and the above four filters are respectively mounted in the holes. I have. The filter plate 421 to which these four filters are attached is
The rotating member 420 is configured.

In mounting the filters, for example, the filter plate 421 has a two-stage configuration of a large-diameter hole and a small-diameter hole, and the outer shape of each filter is fitted into the large-diameter hole. I just need. In order to fix the filter, an adhesive is used, or the holding plate is fixed to the filter plate 421 with screws while holding the outer edge of the filter with a ring-shaped holding plate.

Gears are provided on the outer periphery of the filter plate 421 and mesh with gears attached to the output shaft of the motor 422. The motor 422 drives the filter plate 421 to rotate via a gear under the control of the imaging controller 50, and controls any one of the optical axes of the band-pass filter 423, the red transmission filter 424, the green transmission filter 425, and the blue transmission filter 426. Is the light receiving lens system 4
The filter plate 421 is positioned at a position coinciding with the first optical path.

The inner diameter of the hole provided in the filter plate 421 and the effective diameter of each filter are set to be sufficiently larger than the maximum optical path diameter Ex of the light (light flux) UC incident from the light receiving lens system 41 on the filter surface. Have been. Therefore,
Even if the positioning accuracy of the filter plate 421 by the motor 422 is poor, all of the incident light UC passes through the filter without being blocked by the filter plate 421 and passes through the filter.
3 is imaged. Photographing information obtained by receiving light by the light receiving element 43 is transferred to processing circuits 53 to 56 corresponding to each filter.

FIG. 14 is a graph showing the spectral transmission wavelength of each filter. FIG. 14A shows a band-pass filter 42.
3, FIG. 14 (b) shows a red transmission filter 424, FIG.
14C shows the spectral transmission wavelength of the green transmission filter 425, and FIG. 14D shows the spectral transmission wavelength of the blue transmission filter 426.

The bandpass filter 4 shown in FIG.
Reference numeral 23 denotes a filter that transmits light in the oscillation wavelength band of the semiconductor lasers 21 and 31 (λ = 690 nm in this embodiment). The bandpass filter 423 selectively transmits the measurement slit light U at the time of three-dimensional measurement.

The filters 424 to 426 for the respective colors shown in FIGS. 14B to 14D have spectral transmission wavelengths corresponding to red, green, and blue, respectively, necessary for forming a color image.

As a result, an image obtained by three-dimensional measurement (measurement data Ds) and a red image, a green image, and a blue image obtained by two-dimensional photographing are produced by the same light receiving element 43 under the same conditions, for example, the light receiving lens system 41. Can be photographed with the same amount of extension, the same angle of view, and the like, and image information without positional displacement between the images can be obtained.

Furthermore, since each image is photographed by using a dedicated filter having its own spectral transmission wavelength, data with less noise due to unnecessary wavelength components can be obtained, and measurement accuracy can be improved. Can be planned. [Two-axis adjustment mechanism of optical unit] Next, the optical unit O
The two-axis adjustment mechanism provided in U will be described.

FIG. 15 is a perspective view for explaining the outline of the biaxial adjustment mechanism of the optical unit OU. As shown in FIG. 15, the optical unit OU includes a light projecting optical system 20 and a light receiving optical system 40 attached to brackets 201 and 401.

These two brackets 201, 401
Are connected to each other so as to be rotatable about a rotation axis AX4 which is a Y-direction axis. The light projecting optical system 20 is attached to the bracket 201 so as to be rotatable around a rotation axis AX1 that is a Z-direction axis.

The light receiving optical system 40 is fixed to a bracket 401. The rotation axis AX1 is adjusted to be parallel to the light receiving axis AX3 of the light receiving optical system 40. The base line AS connecting the projection point A of the light projecting optical system 20 and the imaging surface S of the light receiving optical system 40 is perpendicular to the light receiving axis AX3.
The imaging surface S is perpendicular to the refracted light receiving axis AX3.
The details of the biaxial adjustment method of the optical unit OU are disclosed in JP-A-9-145320. [Auto Focusing Control] In focusing the light receiving optical system 40, the user can select manual focusing or auto focusing by operating the focusing switching buttons 8a and 8b.

When the manual focusing is selected, the user looks at the monitor image displayed on the liquid crystal display 6 and operates the manual focusing buttons 9a and 9b.
By operating, focusing driving of the light receiving lens system 41 is performed, and the user can focus on the monitor visually.

When auto-focusing is selected, the system controller 52 performs focusing control based on a focus detection method described later. There are various types of focus detection methods that have been conventionally proposed.
For example, the contrast of shooting information is calculated in accordance with the extension of the light receiving lens, and the focus position is the position at which the contrast is maximized. There is a "phase difference method" in which light is focused and a focus state is detected based on the phase difference between the images.

Next, the system controller 52 refers to the discrimination result (lens type Lk) of the lens detector 44 and the lens information table T2 to determine the focusing feed amount Ed corresponding to the obtained inter-object distance d0. The light receiving lens system 41 is moved to a focus position by performing drive control of the focusing drive system 47 to perform auto-focusing control.

The lens information table T2 shows the relationship between the distance d0 between the objectives, the focusing feed amount Ed, and the image distance b in the light receiving lens system 41, and the distance H between the lens principal points.
A table (not shown) built in the system controller 52 as a table corresponding to the lens type Lk of the light receiving lens system 41.
Is stored in [Preliminary measurement] When the release button 10 is operated, the measurement is performed in the order of preliminary measurement and main measurement. In the preliminary measurement, the operation setting of the main measurement and information on the measurement conditions in the main measurement are acquired.

The operation setting items for the main measurement include the output (laser light intensity) of the semiconductor laser 21 and the measurement slit light U
(A projection start angle and a projection end angle for specifying a projection angle range, a deflection angular velocity), and the like. The information on the measurement conditions to be acquired includes photographing condition data. [Determination of Inter-Object Distance and Lens Driving Setting] The inter-object distance d for setting the optimum measurable range is determined, and the light receiving lens extension amount Ed is set.

At the time of preliminary measurement, the measuring slit light U is projected from the light projecting optical system 20. The projection angle θa is set such that the reflected light is incident on the center of the imaging surface S on the assumption that a planar object exists at the approximate inter-object distance d0.

The system controller 52 obtains the inter-object distance d0 by triangulation based on the slit image position data. As shown in FIG. 16A, the reference position for calculating the inter-object distance is set to the proximity position of the object (the three-dimensional camera 2).
Side), and before and after that, the same amount of measurable range d '
Is set, the measurable range on the front side (the side of the three-dimensional camera 2) is often wasted.

Therefore, as shown in FIG. 16B, the shift amount pitchoff is set, and the measurable range d 'is shifted to the rear side so that the ratio becomes 25% on the front side and 75% on the rear side. desirable.

Accordingly, the distance d between the objectives in the actual measurement is
As shown in the following formula, it is desirable to set the distance by adding 25% of the measurable range d 'to the obtained distance between the objects d0.

D = d0 + d ′ / 4 Based on the determined inter-object distance d, the system controller 52 refers to the discrimination result (such as the lens type Lk) of the lens detector 44 and the lens information table T2 to obtain the value. The focusing feeding amount Ed corresponding to the inter-object distance d is output to the lens controller 51, and the focusing drive system 47 drives and controls the light receiving lens 41. [Main Measurement] In the main measurement, the object Q is scanned by the measurement slit light U, the measurement data Ds for five frames per pixel is generated by the output processing circuit 53, and sent to the host 3. At the same time, deflection information (deflection control data Da) and device information Db indicating the specifications of the light receiving element 43 are also sent to the host 3.

As shown in FIG. 25, in the host 3, the calculation of the center of gravity of the slit # 31, the calculation of the camera line-of-sight equation # 33, the calculation of the slit plane equation # 34, the correction of the distortion # 32, and the three-dimensional position calculation Step # 35 is executed. [Correction calculation of distortion] Geometric aberration depends on the angle of view. Distortion occurs symmetrically about the center pixel. Therefore, the amount of distortion is represented by a function of the distance from the center pixel. Here, the distance is approximated by a cubic function. The secondary correction coefficient is d1, and the tertiary correction coefficient is d2. The corrected pixel positions u ′ and v ′ are given by the following equations (8) and (9).

[0114]

(Equation 1)

[Three-Dimensional Position Calculation] The three-dimensional position (coordinates X, Y, Z) of the sampling point is determined by the camera line of sight (a straight line connecting the sampling point and the front principal point H) and the slit plane (measurement for irradiating the sampling point This is the intersection with the optical axis plane of the slit light U).

By calculating the intersection of the camera line-of-sight equation and the slit plane equation, the three-dimensional positions (coordinates X, Y, Z) of 480 × 640 sampling points are calculated. For calibration, IEICE Technical Report, PRU91-113 [Geometric correction of images without camera positioning] Onodera and Kanaya, IEICE Transactions D-II vol. J74-D-II No.9 pp.1227-123
5, '91 / 9 [High-precision calibration method of range finder based on three-dimensional model of optical system] Ueshiba, Yoshimi, Oshima, etc. have detailed disclosure.

In the above embodiment, the flange portion 494 is provided.
Are provided with pins 496a and 496b.
Pins 496a and 496b may be provided on 1a. One pin 496a is connected to the flange portion 494, and the other pin 496 is
b may be provided on the flange portion 411a. Pin 496
a, 496b and the number of holes 416a, 416b may be three or more. Instead of the O-rings 414a and 414b, it is also possible to use synthetic rubber of another shape, a plate spring, a coil spring, or the like.

In the above embodiment, the light receiving lens system 41
The components of each part such as the lens mounting part 49 and the like can be manufactured using aluminum alloy, stainless steel alloy, other metal materials, synthetic resin, synthetic rubber, glass, ceramics or the like. Structure, shape, size, number, material, processing content, processing of the entire or each part of the light receiving lens system 41, the lens mounting part 49, the light projecting optical system 20, the light receiving optical system 40, the three-dimensional camera 2, or the measuring system 1 Can be appropriately changed in accordance with the gist of the present invention.

The present invention can be applied to various devices or devices using a lens, such as a measuring device other than the measuring system 1 or a camera.

[0120]

According to the present invention, it is possible to improve the positioning accuracy of the lens by replacing the light receiving lens and the like, and to reduce the positional deviation between the lens and the imaging surface to improve the accuracy of photographing or measurement.

According to the fourth to sixth aspects of the present invention, the light receiving lens system can be tightened by the screw ring with uniform force without distortion, and the light receiving lens can be prevented from moving when the screw ring is tightened. .

According to the fifth aspect of the present invention, the rotation of the rotating ring can be restricted by the rotation locking mechanism, and the rotation of the rotating ring due to the rotation of the screw ring can be prevented. Can be automatically switched between locking and unlocking the rotation.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a measurement system according to the present invention.

FIG. 2 is a diagram illustrating an appearance of a three-dimensional camera.

FIG. 3 is a block diagram illustrating a functional configuration of a three-dimensional camera.

FIG. 4 is a schematic diagram showing a configuration of a light projecting optical system.

FIG. 5 is a diagram schematically showing a configuration of a light receiving optical system.

FIG. 6 is an end view showing a configuration of a light receiving lens system and a lens mounting portion when not mounted.

FIG. 7 is an end view showing a configuration of a light receiving lens system and a lens mounting portion when mounted.

FIG. 8 is a front view of a light receiving lens.

FIG. 9 is an enlarged view showing a flange portion of the light receiving lens.

FIG. 10 is an enlarged view showing a part of FIG. 7;

FIG. 11 is a diagram illustrating an example of the shape of a detection blade.

FIG. 12 is a diagram illustrating an example of a detection signal of a sensor.

FIG. 13 is a perspective view showing a filter exchanger.

FIG. 14 is a graph showing the spectral transmission wavelength of each filter.

FIG. 15 is a perspective view schematically illustrating a biaxial adjustment mechanism of the optical unit.

FIG. 16 is a diagram illustrating a relationship between a reference position for calculating the distance between objectives and a measurable range.

FIG. 17 is a diagram showing a data flow in the host.

FIG. 18 is a diagram showing an outline of a slit light projection method.

FIG. 19 is a diagram for explaining the principle of measurement by the slit light projection method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measurement system 40 Light-receiving optical system 41 Light-receiving lens system 43 Light-receiving element 44 Sensor 49 Lens mounting part 401 Bracket (body) 411 Light-receiving lens (lens) 411a Flange part 413 Screw ring 414a, 414b O-ring (elastic member) 416a, 416b Hole 417 Detection blade 491 Fixed ring (body) 492 Rotating ring 493 Helicoid screw 494 Flange part 494a Lock hole 496a, 496b Pin 501 Slider 502 Compression spring 504 Lock pin 505 Sensor LF Lens hood (Regulator) LM Rotation lock mechanism

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 15/00 G03B 15/00 T 17/14 17/14 G01B 11/24 K F-term (Reference) 2F065 AA04 FF09 GG06 HH05 JJ26 LL08 LL15 LL21 MM16 PP22 QQ24 QQ31 SS13 SS15 UU02 UU03 2H044 AB07 AB25 AC01 AE01 AE06 AJ06 AJ07 HB00 2H101 EE08 EE11 EE13 EE21 EE23 EE24 EE32 EE52 EE56

Claims (6)

[Claims] 1. A mounting device for detachably mounting a lens to a main body, wherein said main body or said lens is provided with a pin and a hole into which said pin fits. An elastic member is provided for pressing the pin in one direction on the inner peripheral surface of the hole, and the pin is fitted into the hole and abuts on one location on the inner peripheral surface of the hole, whereby the radial direction of the lens is increased. Alternatively, the lens mounting device is configured to be positioned in a circumferential direction. 2. A main body and a flange portion of the lens are provided with an abutting surface for axially abutting and positioning each other, and are screwed together with the main body by a screw, and the main body is tightened when the screw is tightened. And a screw ring for pressing and fixing the contact surfaces of the flange portions of the lens to each other, and a direction in which the elastic member presses the pin against the inner peripheral surface of the hole and a direction in which the screw of the screw ring is tightened. The lens mounting device according to claim 1, which substantially coincides with: 3. The apparatus according to claim 2, wherein said body or said lens has at least two
One pin and a hole into which each pin fits, the elastic member provided in one hole presses the pin in a direction along the radial direction of the lens, and the elastic member provided in another hole The lens mounting device according to claim 1, wherein the pins are arranged so as to press the pins in a direction along a circumferential direction of the lens. 4. An attachment device for detachably attaching a lens to a main body, wherein the main body is provided with a fixed frame, and a rotating ring movable in an axial direction by a screw with respect to the fixed frame. A pin and a hole into which the pin fits are provided on the rotating ring or the lens detachably provided on the rotating ring; An elastic member for pressing in the direction is provided, and the elastic member is arranged so as to press the pin in a direction along a radial direction or a circumferential direction of the lens. A lens mounting device, characterized in that the lens is positioned in a radial direction or a circumferential direction by contacting one position on an inner peripheral surface. 5. A regulating member detachably attached to the main body in front of the lens, a rotation lock mechanism for regulating rotation of the rotating ring is provided on the fixed frame, and the rotation lock is provided. The mechanism is configured such that when the restricting member is removed, the lock pin biased by the elastic member engages with the lock hole, and when the restricting member is attached,
The lens mounting device according to claim 4, wherein the regulating member is configured to move the lock pin against the urging force of the elastic member to release the engagement with the lock hole. 6. The lens is provided with a detection blade, and the fixed frame is provided with a sensor for detecting the detection blade in accordance with the rotation of the lens. The lens mounting device according to the above.