JP2000028335A - Three-dimensional inputting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To input three-dimensional data of resolution of the same degree as that of the case that a depth size is small even in the case of an object having a large depth size by continuously scanning plural times a detecting light at different projecting angle ranges. SOLUTION: A measuring system 1 has a three-dimensional camera 2 for stereoscopically measuring by a slit light projecting method, and a host system 3 for processing output data of the camera 2. The camera 2 outputs a two-dimensional image indicating color information of an object Q and data necessary for its calibration together with measured data for specifying three-dimensional positions of a plurality of sampling points on the object Q. A detecting light (slit light) is projected, a detected light reflected on the object Q is receiver, and converted into an electric signal. In this case, a plurality of operations having different projecting angle ranges of the detected light are continuously conducted in response to a designation of starting the operation. The designation of starting the operation is conducted by an operation of a switch or a button or a control signal from an exterior.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional input device for projecting detection light onto an object, scanning the object, and outputting data for specifying the shape of the object.

[0002]

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

[0003] As a measurement method suitable for a range finder, a slit light projection method (also called a light cutting method) is known. In this method, an object is optically scanned and a distance image (3
(A two-dimensional image), and is a type of active measurement method for capturing an object by irradiating specific detection light. The distance image is a set of pixels indicating three-dimensional positions of a plurality of parts on the object. In the slit light projection method, a slit light in which a cross section of a projection beam is a straight band is used as detection light. At a certain point during the scanning, a part of the object is irradiated, and the position of the part can be calculated by a triangulation method from the projection direction and the high luminance position (that is, the light receiving direction) on the light receiving surface. Therefore, a group of data specifying the shape of the object can be obtained by sampling the brightness of each pixel on the light receiving surface.

Some range finders adjust the projection angle range of the detection light by measuring the distance between the objects. That is, operation control is performed to set the start and end angle positions of the projection so that the entire object reflected on the light receiving surface is in the scanning range according to the imaging magnification and the distance between the objects. Also,
In the sampling of the luminance of the light receiving surface, there is known a method in which the target of one sampling is not limited to the entire light receiving surface but to a partial region where the detection light is expected to be incident, and the region is shifted for each sampling. . According to this,
Scanning can be sped up by shortening the time required for one sampling, and the amount of data can be reduced to reduce the load on the signal processing system.

[0005]

However, in the prior art, the object to be measured sometimes protrudes from the measurable range in the depth direction. In such a case, the operator changes the angle of view by performing zooming or focus adjustment. It was necessary to re-measure. When the angle of view is increased, the measurable range in the depth direction is also increased, but the resolution is reduced. In the case where a part of the light receiving surface is subjected to one sampling, if the target area is expanded, the measurable range is expanded. However, the scanning speed must be reduced, and the burden of data processing increases.

SUMMARY OF THE INVENTION It is an object of the present invention to enable input of three-dimensional data having the same resolution as the case where the depth dimension is small, even when the depth dimension of the object is large.

[0007]

According to the present invention, a plurality of scans are performed by automatically changing the projection angle range of the detection light. As a result, even for a part on an object for which effective light reception information cannot be obtained in one scan, appropriate light reception information can be obtained in another scan. In other words, the receivable range in the depth direction is the sum of the receivable ranges in each scan, and is in principle expanded to twice the number of scans.

According to a first aspect of the present invention, there is provided an apparatus comprising: a light projecting means for projecting a detection light; and an imaging means for receiving the detection light reflected by an object and converting the detection light into an electric signal. What is claimed is: 1. A three-dimensional input device which performs scanning for periodically imaging an object by changing a direction, and continuously performs a plurality of scans having different projection angle ranges of the detection light in response to an operation start instruction. What to do. The instruction to start the operation is given by operating a switch or button or by a control signal from the outside.

[0009]

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 (range finder) 2 that performs three-dimensional measurement by a slit light projection method, and a host 3 that processes output data of the three-dimensional camera 2.

The three-dimensional camera 2 outputs two-dimensional images indicating color information of the object Q and data necessary for calibration, together with measurement data for specifying the three-dimensional positions of a plurality of sampling points on the object Q. The calculation processing for obtaining the coordinates of the sampling points using the triangulation method is performed by the host 3.
Is responsible.

The host 3 comprises 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,
There are a magneto-optical disk (MO), a mini disk (MD), and a memory card.

FIG. 2 is a diagram showing the appearance of the three-dimensional camera 2. A light emitting window 20a and a light receiving window 2
0b is provided. The light projecting window 20a is located above the light receiving window 20b. Slit light (band-like laser beam with a predetermined width w) U emitted from the internal optical unit OU
Goes to the object (subject) to be measured through the light emitting window 20a. The radiation angle φ in the length direction M1 of the slit light U is fixed. A part of the slit light U reflected on the surface of the object enters the optical unit OU through the light receiving window 20b. Note that the optical unit OU includes a two-axis adjustment mechanism for optimizing the relative relationship between the light projecting axis and the light receiving axis.

On the upper surface of the housing 20, zooming buttons 25a and 25b, a manual focusing button 26
a, 26b, and a shutter button 27 are provided. As shown in FIG. 2B, on the back of the housing 20,
A liquid crystal display 21, a cursor button 22, a select button 23, a cancel button 24, an analog output terminal 32, a digital output terminal 33, and an opening 30a for the recording medium 4 are provided.

A liquid crystal display (LCD) 21 is used as display means for an operation screen and as an electronic finder.
The photographer can set the photographing mode by using the buttons 21 to 24 on the back. From the analog output terminal 32, a two-dimensional image signal is output, for example, in the NTSC format. The digital output terminal 33 is, for example, a SCSI terminal.

FIG. 3 is a block diagram showing a functional configuration of the three-dimensional camera 2. As shown in FIG. In the figure, solid arrows indicate the flow of electric signals, and broken arrows indicate the flow of light. 3D camera 2
Has two optical systems 40 and 50 on the light projecting side and the light receiving side that constitute the optical unit OU described above. Optical system 40
, The wavelength 6 emitted by the semiconductor laser (LD) 41
The 70 nm laser beam becomes slit light U by passing through the light projecting lens system 42 and is deflected by the galvanomirror (scanning means) 43. Semiconductor laser 4
The driver 44, the driving system 45 of the light projecting lens system 42, and the driving system 46 of the galvanomirror 43 are controlled by a system controller 61.

In the optical system 50, a zoom unit 51
The light condensed by the beam splitter 52 is split by the beam splitter 52. The light in the oscillation wavelength band of the semiconductor laser 41 is
The light enters the sensor 53 for measurement. Light in the visible band enters the monitor color sensor 54. The sensor 53 and the color sensor 54 are both CCD area sensors. The zoom unit 51 is of an in-focus type, and a part of the incident light is used for auto focusing (AF). The AF function is realized by the AF sensor 57, the lens controller 58, and the focusing drive system 59. The zooming drive system 60 is provided for electric zooming.

The information captured by the sensor 53 is transmitted to the driver 5.
The data is input to the output processing circuit 62 in synchronization with the clock from 5, and is temporarily stored in the memory 63 as 8-bit light receiving data. The address specification of the memory 63 is performed by the memory controller 63A. At a predetermined timing, the received light data is transferred from the memory 63 to the center-of-gravity calculating circuit 73, and data serving as a basis for calculating the three-dimensional position of the target object ("center of gravity ip" described later) is generated. The center of gravity ip is sent to the SCSI controller 66 via the output memory 64 as a measurement result. The center of gravity ip is also sent from the center of gravity calculation circuit 73 to the display memory 74 as monitor information, and is used for displaying a distance image on the liquid crystal display (LCD) 21.

On the other hand, imaging information from the color sensor 54 is sent to the color processing circuit 67 in synchronization with a clock from the driver 56. Imaging information that has undergone color processing
The data is output online via the NTSC conversion circuit 70 and the analog output terminal 32, or is quantized by the digital image generation unit 68 and stored in the color image memory 69. Thereafter, the color image data is transferred from the color image memory 69 to the SC.
The data is transferred to the SI controller 66.

The SCSI controller 66 outputs the data and the color image from the output memory 64 on-line from the digital output terminal 33 or stores them in the recording medium 4. Note that the color image is an image having the same angle of view as the distance image based on the output of the sensor 53, and is used as reference information during application processing in the host 3. 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. System controller 6
1 is L for a character generator (not shown).
An instruction for displaying appropriate characters and symbols on the screen of the CD 21 is given.

FIG. 4 is a schematic diagram of a zoom unit 51 for receiving light. The zoom unit 51 includes a front image forming unit 51
5, a variator unit 514, a compensator unit 513, a focusing unit 512, a rear image forming unit 511, and a beam splitter 516 for guiding a part of incident light to the AF sensor 57.
It is composed of The front imaging unit 515 and the rear imaging unit 511 are fixed with respect to the optical axis.

The movement of the focusing unit 512 is performed by the focusing drive system 59, and the movement of the variator unit 514 is performed by the zooming drive system 60. Focusing drive system 5
Reference numeral 9 denotes a focusing encoder 59 which indicates a moving distance (lens extension amount Ed) of the focusing unit 512.
A is provided. The zooming drive system 60 includes a zooming encoder 60A that indicates the moving distance (lens increment value fp) of the variator unit 514.

FIG. 5 is a diagram illustrating the principle of calculating a three-dimensional position in the measurement system 1, and FIG. 6 is a diagram illustrating the concept of the center of gravity ip. Although FIG. 5 shows only five samplings of the amount of received light for easy understanding, the number of samplings per pixel in the three-dimensional camera 2 is 32.

As shown in FIG. 5, a relatively wide slit light U having a slit width on the imaging surface S2 of the sensor 53 corresponding to a plurality of pixels g arranged at a pitch pv is projected on the object Q. Specifically, the width of the slit light U is set to about 5 pixels. The slit light U is deflected at a constant angular velocity about the starting point A in the vertical direction in the figure. The slit light U reflected by the object Q passes through the principal point O of image formation (the principal point H ′ on the rear side of zooming) and enters the imaging surface S2. During the projection of the slit light U, the sensor 53
The object Q (strictly speaking, an object image) is scanned by periodically sampling the amount of received light. The photoelectric conversion signal for one frame is output from the sensor 53 every sampling period (sensor driving period).

If the surface of the object Q is flat and there is no noise due to the characteristics of the optical system, the image pickup surface S2 of the sensor 53
The light reception amount of each pixel g at the time Npea at which the optical axis of the slit light U passes through the object surface ag in the range where the pixel g is viewed
It becomes maximum at k, and its temporal distribution is close to a normal distribution. In the example of FIG. 5B, the time point Npeak is between the n-th sampling time and the immediately preceding (n-1) -th sampling time.

In the present embodiment, one frame is composed of 32 lines corresponding to a part of the imaging surface S2 of the sensor 53. Therefore, focusing on one pixel g on the imaging surface S2, sampling is performed 32 times during scanning, and 32 pieces of light reception data are obtained. The center of gravity (time center of gravity) ip corresponding to the time point Npeak is calculated by the center of gravity calculation on the light reception data for these 32 frames.

The center of gravity ip is the center of gravity of the distribution of 32 pieces of received light data obtained by sampling 32 times as shown in FIG. Sampling numbers 1 to 32 are assigned to 32 pieces of received light data for each pixel. The i-th light reception data is represented by xi. i is an integer of 1 to 32. At this time, i indicates the number of frames since the pixel of interest enters the effective light receiving area consisting of 32 lines.

The center of gravity ip of the received light data x1 to x32 of Nos. 1 to 32 is i ·
It is obtained by dividing the sum Σi · xi of xi by the sum Σxi of xi. That is,

[0028]

(Equation 1)

## EQU1 ## The center-of-gravity calculation circuit 73 performs the calculation of the equation (1) to calculate the center of gravity ip (that is, the time center of gravity Npea).
k) is calculated. The host 3 applies the triangulation method based on the relationship between the irradiation direction of the slit light U at the calculated center of gravity ip and the incident direction of the slit light U to the target pixel g to change the position (coordinate) of the object Q. calculate. This enables measurement with a higher resolution than the resolution specified by the pitch pv of the pixel array on the imaging surface S2.

Next, the operation of the three-dimensional camera 2 unique to the present invention will be described together with the operation and measurement procedure of the host 3. The user (photographer) determines the camera position and orientation and sets the angle of view while viewing the color monitor image displayed on the LCD 21. At that time, one or both of a zooming operation and a focusing operation are performed as necessary. The variator unit 514 and the focusing unit 512 in the zoom unit 51 move according to the operation, and the lens step value (fp) and the lens extension amount (Ed) at that time are sequentially changed via the lens controller 58 and the system controller 6.
Sent to 1. The system controller 61 calculates the inter-object distance D using a conversion table created based on the equation (2) in advance.

D = G (fp, Ed) (2) G: Function When the user turns on the shutter button 27, the angle of view is set. In response to this, the system controller 61 determines the deflection conditions (scan start angle, scan end angle, deflection angular velocity) of the slit light U based on the determined inter-object distance D.
Set.

FIG. 7 is a schematic diagram showing the positional relationship between a main point of the optical system and an object. The basic contents of setting the deflection conditions are as follows. Assuming that the reference plane Ss exists at the position of the inter-object distance D, an area (projected) of the reference plane Ss that is projected (projected) on the imaging plane S2 is determined from the imaging magnification. The scanning start angle and the scanning end angle are determined so that the slit light U is projected from the lower end side over the entire area, and the deflection angular velocity is determined so that the required scanning time becomes a constant value.

In the actual setting, the Z-direction offset Doff between the front principal point H of the light receiving system, which is the distance measurement reference point of the inter-object distance D, and the projection start point A is considered. Further, in order to secure the same measurable distance range d at the end in the scanning direction as at the center, an overscan of a predetermined amount (for example, for 16 pixels) is performed. The scan start angle th1, the scan end angle th2, and the deflection angular velocity ω are represented by the following equations. th1 = tan ⁻¹ [β × pv (np / 2 + 16) + L) / (D + Doff)] × 180 / π (3) th2 = tan ⁻¹ [−β × pv (np / 2 + 16) + L) / (D + Doff) × 180 / π (4) ω = (th1−th2) / np (5) β: imaging magnification (= D / effective focal length freal) pv: pixel pitch np: effective pixel in the Y direction of the imaging surface S2 Number L: Base Line Length Here, the measurable distance range d depends on the number of lines of one frame in the reading operation of the sensor 53. The measurable distance range d increases as the number of lines increases, but the readout time increases, the data amount increases, and the processing load increases. Based on this, in the present embodiment, the number of lines in one frame is set to 32 as described above.

If the size of the object Q is within the measurable distance range d, the object Q can be measured by one scan. However, when a part of the object Q extends beyond the measurable distance range d, such as when the dimension of the object Q in the depth direction (Z direction) is large, shape data for that part cannot be obtained.

Therefore, the three-dimensional camera 2 automatically changes the position of the reference plane Ss multiple times (specifically, three times) in response to turning on of the shutter button 27 which is an instruction to start the measurement operation. Is continuously performed. Thereby, shape data in a range wider than the measurable distance range d can be obtained without lowering the resolution.

FIG. 8 is a diagram showing an example of a change in the position of the reference plane Ss. In the first scan, the reference plane Ss is set to the distance D between the objects.
At the position Z0, and the distance D1 between the objectives in the second scan
(D1 <D) is set to the position Z1, and in the third scan, the position is set to the position Z2 of the inter-object distance D2 (D2> D). That is, the reference plane Ss is moved to the near side in the second time, and is moved to the rear side in the third time. However, the position of the reference surface Ss and the order of scanning are arbitrary, and there is no problem even if scanning on the rear side is performed earlier than scanning on the near side. Object distance D1,
D2 is set such that the measurable distance ranges d2 and d3 in the second and third scans partially overlap the measurable distance ranges d in the first scan, respectively. By overlapping the measurable distance ranges d, d2, and d3, it becomes easy to combine the shape data obtained in each scan. Since the imaging magnification is fixed in a total of three scans,
If the position of the reference surface Ss changes, the angle range in which the slit light U is projected also changes. Therefore, the deflection condition is calculated for each scan.

FIGS. 9 and 10 are diagrams for explaining the measurable distance range. As shown in FIG. 9, the reference plane Ss is moved to the position Z.
When 0 is set, when the address in the Y direction of the pixel passing through the light receiving axis on the imaging surface S2 is nc, the scanning angle θ1 at the time of starting sampling the pixel at the address nc is θ1 = th1−ω × (nc− 1) ... (6) The address in the Y direction is incremented from 1, 2, 3,... With the start address (scanning start address) as 1.

The scanning angle θ2 at the time when the sampling of the pixel at the address nc is completed can be obtained by the following equation, where the number of samplings per pixel is j (32 in this example). θ2 = θ1−ω × (j−1) (7) Measurable distance range d ′ for the pixel at address nc
Is the depth range from the intersection Z1 between the projection axis of the scanning angle θ1 and the line of sight of the pixel at the address nc to the intersection Z2 between the projection axis of the scanning angle θ2 and the line of sight of the pixel at the address nc.

Similarly, an address nm other than the address nc
, The scanning angles θ1m and θ2m at the sampling start and end times can be obtained. The measurable distance range dm for the pixel at the address nm is, as shown in FIG. 10, from the intersection Z1m between the projection axis of the scanning angle θ1m and the line of sight of the pixel, and the intersection Z2m of the projection axis of the scanning angle θ2m and the line of sight of the pixel.
To the depth range.

FIGS. 11 and 12 are views for explaining the procedure for setting the deflection conditions. For the second scan,
The scanning start angle th1a and the scanning end angle th2a are determined using the limit position Z1 on the near side (left side in the figure) of the measurable distance range d as a reference position.

Since tan θ1 = L / (Doff + D1), D1 = (L / tanθ1) −Doff (8)

The distance D1 between the objectives is obtained from the equation (7), and the above equations (3) and (4) are applied. Scanning start angle th1a
And the scan end angle th2a are expressed by the equations (9) and (10). th1a = tan ⁻¹ [β × pv (np / 2 + 16) + L) / (D1 + Doff)] × 180 / π (9) th2a = tan ⁻¹ [−β × pv (np / 2 + 16) + L) / (D1 + Doff) × 180 / π (10) At this time, the deflection angular velocity ωa is as follows: ωa = (th1a−th2a) / np (11)

Similarly, for the third scan, the scan start angle th1b and the scan end angle th2 are set with the limit position Z2 on the rear side (right side in the figure) of the measurable distance range d as a reference position.
Find b. Scan start angle th1b and scan end angle th2
b is expressed by the equations (12) and (13). th1b = tan ⁻¹ [β × pv (np / 2 + 16) + L) / (D2 + Doff)] × 180 / π (12) th2b = tan ⁻¹ [−β × pv (np / 2 + 16) + L) / (D1 + Doff) × 180 / π (13) At this time, the deflection angular velocity ωb is as follows: ωa = (th1b−th2b) / np (14)

The deflection conditions (th1,
th2, ω), (th1a, th2a, ωa), (th
1b, th2b, and ωb), a total of three scans makes the range d ′ from position Z11 to position Z22 measurable for the pixel at address nc (see FIG. 8).

It is sufficient that the number of scans is two or more.
As described above, the measurable distance range may be further expanded. 2
If the deflection conditions for the fourth and subsequent scans are determined based on the deflection conditions for the third and third scans, the measurable distance ranges for each scan can be reliably overlapped.

In each scan, the distances D, D1, D
Auto-focusing for adjusting the lens extension amount Ed according to 2 is performed. The system controller 61
The lens extension amount Ed is obtained using a conversion table created in advance based on Expression (15), and is provided to the lens controller 58 as a control target value.

Ed = F (D, fp) (15) F: Function In each scan, the variator unit 514 is fixed to the state set by the operator, and the lens step value fp = fp0. Applying the inter-object distances D1 and D2 obtained by the first deflection conditions (th1, th2, ω) to the equations (16) and (17), the system controller 61 determines the lens extension amount in the second and third scans. Ed1 and Ed2 are calculated.

Ed1 = F (D1, fp0) (16) Ed2 = F (D2, fp0) (17) FIG. 13 is a flowchart showing an outline of the operation of the three-dimensional camera 2.

When the start of measurement is instructed by the shutter button 27, the system controller 61 calculates deflection conditions for the first scan, and based on the calculation results, the second and third deflection conditions.
Are calculated (# 50- # 52).

The deflection conditions for the first scanning are set and scanning is started (# 53, # 54). The projection of the slit light U and the sampling of the amount of light received by the sensor 53 are started.
Scanning is performed until the deflection angle position reaches the scan end angle th2.

When the first scan is completed, the system controller 61 sets the deflection conditions for the second scan (# 5).
5, # 56). Further, the lens extension amount Ed2 under this deflection condition is obtained, and the movement of the focusing unit 512 is instructed to the focusing drive system 59 via the lens controller 58 (# 57).

When the movement of the focusing unit 512 is completed, the second scanning is started (# 58, # 59). When the second scan is completed, the system controller 61 sets the deflection conditions for the third scan, and instructs movement of the focusing unit 512 (# 60 to # 62). When the focusing is completed, the third scan is started (# 63, # 64).

When the third scan is completed, data processing control for displaying a distance image showing the results of the three measurements on the monitor and outputting the center of gravity ip based on the received light data obtained in the scans specified by the operator. (# 65, # 66).

FIG. 14 is a diagram showing an example of monitor display contents. As shown in FIG. 14B, the object to be measured is located at the position Z1.
1 and the position Z22, the object Q in each scan
Is measured. As shown in FIG. 14A, on the liquid crystal display 21, three distance images g1, g2, and g3 indicating the results of each scan are displayed side by side in the order of the position of the reference plane. That is, with the distance image g1 corresponding to the first scan in the middle, the distance image g2 corresponding to the second scan on the left, and the distance image g3 corresponding to the third scan on the right.
Is displayed.

The operator designates the number of scan results to be output by using the cursor button 22 and the select button 23. Two or more scans may be specified, or one of them
You may specify the number of scans. In the example of FIG. 14, the first scan and the second scan are designated as indicated by upward arrows.

The designated scanning result (the center of gravity ip calculated for each of the predetermined number of pixels) is calculated by the center of gravity calculating circuit 7.
3 to the host 3 or the recording medium 4 via the output memory 64 and the SCSI controller 66. At the same time, device information including the deflection conditions and the specifications of the sensor 53 is also output. Table 1 summarizes main data that the three-dimensional camera 2 sends to the host 3.

[0057]

[Table 1]

Hereinafter, data processing in the measurement system 1 will be described. FIG. 15 is a diagram showing a reading range of the sensor 53. The reading of one frame by the sensor 53 is not performed on the entire imaging surface S2, but is performed on the imaging surface S2 for speeding up.
2 is performed only for the effective light receiving area (band-shaped image) Ae which is a part of the area 2. The effective light receiving area Ae is an area on the imaging surface S2 corresponding to the measurable distance range at a certain irradiation timing, and shifts by one pixel for each frame with the deflection of the slit light U. In the present embodiment, the number of pixels of the effective light receiving area Ae in the shift direction is fixed to 32.
A method of reading out only a part of the captured image of the CCD area sensor is disclosed in Japanese Patent Application Laid-Open No. 7-174536.

FIG. 16 is a diagram showing the relationship between lines and frames on the imaging surface S2 of the sensor 53, and FIG. 17 is a diagram showing the storage state of the received light data of each frame. As shown in FIG. 16, the frame 1 which is the first frame of the imaging surface S2 has 32 (lines) × 2 from line 1 to line 32.
The received light data for 00 pixels is included. 200 per line
Pixels. Frame 2 is from line 2 to line 33
, Frame 3 is shifted by one line per frame, such as from line 3 to line 34. Frame 32 is from line 32 to line 63.

The light receiving information from the frames 1 to 32 is sequentially A / D converted and stored in the memory 63 (see FIG. 3). As shown in FIG. 17, received light data is stored in the memory 63 in the order of frames 1, 2, 3 and so on. The data of the line 32 included in each frame is the 32nd line of the frame 1 and the 31st line of the frame 2. Thus, the image is shifted upward by one line for each frame. The sampling of each pixel on the line 32 is completed by storing the received light data from the frame 1 to the frame 32 in the memory 63. The light receiving data of each pixel for which sampling has been completed is sequentially read from the memory 63 in order to perform the center of gravity calculation. The content of the center of gravity calculation is as described above.

The center of gravity ip specifies the position of the surface of the object Q. The value of the center of gravity ip becomes larger as the position of the surface of the object Q is closer to the three-dimensional camera 2, and becomes smaller as the position is farther. Therefore, by displaying a grayscale image using the center of gravity ip as density data, a distance distribution can be realized.

In the host, three-dimensional position calculation processing is executed, and 200 × 200 sampling points (pixels)
Are calculated (coordinates X, Y, Z). The sampling point is the intersection of the camera's line of sight (a straight line connecting the sampling point and the front principal point H) and the slit plane (the optical axis plane of the slit light U illuminating the sampling point).

FIG. 18 is a flowchart showing a processing procedure of the three-dimensional position calculation in the host. First, it is determined whether or not the sum ｉxi of xi sent from the three-dimensional camera 2 exceeds a predetermined value (# 11). When xi is small, that is, when the sum ス リ ッ ト xi of the slit light components does not satisfy the predetermined criterion, a large error is included, and the calculation of the three-dimensional position is not executed for the pixel. Then, data indicating "error" is set and stored for the pixel (# 17). If Σxi exceeds a predetermined value, a sufficient accuracy is obtained, so that the calculation of the three-dimensional position is executed.

Prior to the calculation of the three-dimensional position, the passage timing nop of the slit light U is calculated (# 12). The passage timing nop is (Σi · x) for i = 1 to 32.
i) / (Σxi) is calculated and the centroid ip (time centroid Npe)
ak), and a line number is added thereto.

That is, since the calculated barycenter ip is the timing within the 32 frames at which the output of the pixel is obtained, it is converted to the passage timing nop from the start of scanning by adding the line number. Specifically, the line number is “32” for the pixel of the line 32 calculated first and “33” for the next line 33. Each time the line of the target pixel g advances by one, the line number is 1
Increase. However, these values can be other suitable values. The reason is that when calculating the three-dimensional position, the rotation angle around the X-axis (the1) and the angular velocity around the X-axis (the4) in equation (20), which will be described later, are coefficients.
This can be set appropriately by calibration.

Then, a three-dimensional position is calculated (# 13).
The calculated three-dimensional position is stored in the memory area corresponding to the pixel (# 14), and the same processing is performed for the next pixel (# 16). When the processing for all the pixels is completed, the process exits from the routine (Yes in # 15).

Next, a method of calculating the three-dimensional position will be described. The camera line-of-sight equation is given by the following equations (18) and (19).
It is an expression. (U-u0) = (xp) = (b / pu) × [X / (Z-FH)] (18) (v−v0) = (yp) = (b / pv) × [Y / (Z -FH)] (19) b: Image distance FH: Front principal point position pu: Horizontal pixel pitch on the imaging surface pv: Vertical pixel pitch on the imaging surface u: Horizontal pixel position on the imaging surface u0: Center pixel position in the horizontal direction on the imaging surface v: Pixel position in the vertical direction on the imaging surface v0: Center pixel position in the vertical direction on the imaging surface The slit plane equation is given by equation (20).

[0068]

(Equation 2)

The geometric aberration depends on the angle of view. Distortion occurs in the target substantially at 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 second-order correction coefficient is d1, and the third-order correction coefficient is d2. The corrected pixel positions u ′ and v ′ are given by equations (21) and (22).

[0070] u '= u + d1 × t2 2 × (u-u0) / t2 + d2 × t2 3 × (u-u0) / t2 ... (21) v' = v + d1 × t2 2 × (v-v0) / t2 + d2 × t2 ³ × (v−v0) / t2 (22) t2 = (t1) ⁻² t1 = (u−u0) ² + (v−v0) ^{2 In the} above equations (18) and (19), u U 'instead of
And substituting v ′ for v, a three-dimensional position taking distortion into account can be obtained. 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.1227-1235, '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 distance D between the objectives is calculated by the passive type distance measurement for detecting the positions of the focusing unit and the zooming unit.
May be performed to perform a preliminary measurement for detecting an incident angle, and to perform an active distance measurement for calculating a distance between objectives using a triangulation method. Further, the deflection condition may be set based on the preset inter-object distance without performing the distance measurement, or on the basis of the inter-object distance by setting and input by an operator.

A mode in which scanning is performed only once may be provided so that the operator can specify switching to a mode in which scanning is performed a plurality of times. The calculation for obtaining coordinates from the center of gravity ip is 3
This can be performed inside the two-dimensional camera 2. When this configuration is adopted, a function may be provided in which the result of the first scan is analyzed to automatically determine whether or not the second and subsequent scans are necessary, and a plurality of scans are performed only when necessary. In addition, a configuration may be adopted in which the three-dimensional camera 2 sends the data ・ i · xi and Σxi for each pixel as a measurement result to the host 3 and the host performs a gravity center calculation.

[0073]

According to the first aspect of the present invention, even when the depth dimension of an object is large, three-dimensional data having the same resolution as that when the depth dimension is small can be input for the entire object.

[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 of a zoom unit for receiving light.

FIG. 5 is a principle diagram of calculation of a three-dimensional position in the measurement system.

FIG. 6 is a diagram illustrating a concept of a center of gravity.

FIG. 7 is a schematic diagram of a positional relationship between a main point of the optical system and an object.

FIG. 8 is a diagram illustrating an example of a position change of a reference plane.

FIG. 9 is a diagram for explaining a measurable distance range.

FIG. 10 is a diagram illustrating a measurable distance range.

FIG. 11 is a diagram for explaining a procedure for setting deflection conditions.

FIG. 12 is a diagram for explaining a procedure for setting deflection conditions.

FIG. 13 is a flowchart showing an outline of the operation of the three-dimensional camera 2.

FIG. 14 is a diagram showing an example of monitor display contents.

FIG. 15 is a diagram showing a reading range of a sensor.

FIG. 16 is a diagram illustrating a relationship between a line and a frame on an imaging surface of a sensor.

FIG. 17 is a diagram showing a storage state of received light data of each frame.

FIG. 18 is a flowchart illustrating a processing procedure of a three-dimensional position calculation in the host.

[Explanation of symbols]

2 Three-dimensional camera (three-dimensional input device) 27 Shutter button (component related to operation start instruction) 40 Optical system (light emitting means) 50 Optical system (imaging means) 61 System controller Q Object U Slit light (detection light)

Continued on the front page (72) Inventor Takuto Ueko 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Hideki Tanabe 2-chome, Azuchi-cho, Chuo-ku, Osaka-shi, Osaka No. 3-13 Osaka International Building Minolta Co., Ltd. (72) Inventor Toshio Kaida 2-3-1 Azuchicho, Chuo-ku, Osaka City, Osaka Prefecture Osaka International Building Minolta Co., Ltd. F-term (reference) 2F065 AA04 AA17 BB05 DD03 DD06 FF04 FF09 GG06 HH05 JJ03 JJ05 JJ26 LL06 LL46 MM16 PP22 QQ14 QQ24 QQ29 QQ35 QQ42 SS02 SS11 SS13 UU05 UU07

Claims (1)

[Claims] A light source for projecting the detection light; and an imaging means for receiving the detection light reflected by an object and converting the light into an electric signal. A three-dimensional input device for performing a scan for imaging the object, wherein a plurality of scans having different projection angle ranges of the detection light are performed continuously in response to an instruction to start operation. 3D input device.