KR100902176B1 - 3D scanner using rotating face mirror - Google Patents

Abstract

The present invention is a 3D using a rotating multi-faceted mirror that can improve the measurement speed by projecting a one-dimensional pattern light of a variety of colors using a single rotating multi-faceted mirror and light sources and filters of different colors and acquires the image for each color at once It is about a scanner.

To this end, the present invention, in the 3D scanner, a plurality of light sources provided on one side of the rotating polygon mirror and generating point light having different color information, and to emit light in various directions generated from the respective light sources to the same optical axis An optical filtering means for receiving the light reflected from the reflecting surface of the rotating multi-facet mirror, the optical path recognition means for recognizing an optical path, and generating a synchronization signal, and synchronizing with the synchronization signal generated from the optical path recognition means. Control means for controlling the period and phase of the straight stripes by adjusting the flashing period, and a color camera for imaging the light reflected from the surface of the measurement object.

Description

3D scanner using rotating face mirror {3D SCANNER USING THE POLYGON MIRROR}

The present invention relates to a 3D scanner, which uses a single rotating multi-faceted mirror and light sources and filters of different colors to project one-dimensional patterned light of various colors and to obtain an image for each color at a time, thereby improving measurement speed. A 3D scanner using a rotating mirror.

In general, three-dimensional shape measurement of free-formed objects is widely applied in various fields such as inspection of various workpieces, CAD / CAM, medical care, and solid modeling.

One of the three-dimensional shape measurement technology has been used to measure the entire curved shape by measuring a point on the curved surface by using a contact type 3D measuring device, this contact type 3D shape measurement method has been used It has an excessive problem.

Recently, the optical method has been used to solve the shortcomings of the contact type 3D measuring device and increase the measuring efficiency.

As such, a device for measuring a three-dimensional shape of an object using an optical method is commonly referred to as a "3D scanner".

The three-dimensional scanner comprises an image acquisition unit consisting of a lens and a camera, a pattern light projection unit for projecting pattern light, and a computer for analyzing and processing an image obtained through the pattern light projection unit.

1 is a conceptual diagram illustrating an embodiment of a conventional 3D scanner, and includes an image acquisition unit 100 including a lens 110 and a camera 120 and a pattern light projection unit projecting pattern light onto a surface of a measurement object P. Referring to FIG. It consists of 200.

The pattern light projector 200 uses an LCD or a digital light processing (DLP) method as a digital pattern light projector.

When the digital pattern light projector is used, various colors and various types of pattern light projections are possible through a combination of R (Red), G (Green), and B (Blue) colors.

The digital patterned light projector needs to input two-dimensional image data as shown in FIG. 2.

Therefore, in three-dimensional shape measurement, which projects only one-dimensional pattern, two-dimensional image data must be processed, so that the amount of data increases, and thus, the shape measurement takes a long time.

In addition, expensive and bulky equipment, there is a problem of high power consumption and heat generation.

3 is a conceptual diagram illustrating another embodiment of a conventional 3D scanner, and includes an image acquisition unit 100 including a lens 110 and a camera 120 and a pattern light projection unit projecting pattern light onto a surface of a measurement object P. Referring to FIG. 300.

Here, the pattern light projection unit 300 generates the striped pattern light at a predetermined interval, and is generated by the rotating polyhedron 310 having a plurality of reflective surfaces, the light source 320 generating the point light, and the light source 320. Optical path conversion mirror 350 for detecting the path of the light generated from the condenser lens 330, the cylindrical lens 340, and the light source 310 to convert the point light to a linear light to be incident on the reflecting surface of the rotary polygon mirror 310 And a light receiving sensor 360.

The patterned light projection unit 300 having the rotating multi-faceted mirror 310 has a simple three-dimensional structure by projecting a one-dimensional pattern as shown in FIG. Because it can be measured, there is less data to be processed, so the reaction rate is faster and the price is lower.

On the other hand, since a light source of monochromatic light is used, there is a disadvantage in that it is not possible to project patterns of various colors.

In addition, in the three-dimensional shape measurement using a conventional pattern light projection unit, as shown in Fig. 5, each of the pattern light of phase 0 °, the pattern light of phase 120 ° and the phase 240 ° pattern light is sequentially irradiated onto the measurement object. After obtaining one image for each phase one by one, a moire pattern is obtained by combining three acquired images.

Therefore, in order to obtain a moire pattern, the pattern light projection and the image acquisition process have to be performed three times, respectively, and thus, a long time is required for measurement.

An object of the present invention for solving the problems of the background art, by simultaneously projecting the pattern light for each color to the measurement object to have a different phase by using a plurality of light sources having different colors, and at a time with a color camera By capturing each color information and then combining them to obtain a moire pattern, it is possible to realize various colors with a small amount of input data, and to obtain a measurement speed and reliability by acquiring phase shifted images at one time by one imaging. The present invention provides a 3D scanner using a rotating mirror.

The present invention for solving the above problems, in the 3D scanner, a plurality of light sources provided on one side of the rotating polygon mirror and generating point light having different color information, and the same optical axis to the light in various directions generated from the respective light sources An optical filtering means for outputting the light source, an optical path recognition means for receiving the light reflected from the reflecting surface of the rotating multi-facet mirror, recognizing an optical path and generating a synchronization signal, and a synchronization signal generated from the optical path recognition means. Control means for controlling the period and phase of the straight stripes by adjusting the flashing period of the light source, and a color camera for imaging the light reflected from the surface of the measurement object.

The light filtering means may be constituted by a filter or a beam splitter that emits light from each light source to the same optical axis.

The start point and the end point of the exposure time of the color camera are preferably matched with the synchronization signal generated by the optical path recognition means.

The rotating mirror is preferably rotated at a constant speed at high speed.

The present invention can simultaneously project pattern light of various colors with a plurality of light sources and acquire a surface image of a workpiece having pattern light of various colors with a single color camera, thereby realizing various colors with a small amount of input data. By acquiring the phase shifted image at once, the measurement speed can be improved.

In addition, the present invention has the advantage that the structure is simple by adding a plurality of light sources to the existing 3D scanner having a rotating multi-faceted mirror, so that the power consumption is small and the volume is small, so that the equipment price can be reduced.

Figure 6 is a block diagram of a 3D scanner using a rotating mirror according to the present invention.

Referring to FIG. 6, the rotating polyhedron 10, the plurality of light sources 20: 20a, 20b, 20c, the light filtering means 30, the light path recognition means 40, the control means 50, It includes a color camera 60.

Here, the rotary mirror 10 is for incidence of light incident on the reflective surface through rotation to the surface of the measurement object P in the form of pattern light of a predetermined period, and has a plurality of reflective surfaces.

The rotating multi-face mirror 10 is a constant speed so as to form a pattern light having a stripe of a predetermined interval according to the flashing cycle of each light source (20: 20a, 20b, 20c) through a high-speed rotation to project to the measurement object (P) It is coupled to a spindle motor (not shown) that is driven to rotate on the road, and the spindle motor (not shown) is connected to a motor driver (not shown) having a power supply that reliably supplies power. The configuration is known from Republic of Korea Patent No. 0371078.

  Here, since the rotational inertia 10 is rotated at high speed, the rotational moment of inertia increases and the variation in the rotational speed is extremely small. Therefore, the rotational mirror 10 is preferably rotated at high speed. It is preferable.

In addition, the plurality of light sources 20: 20a, 20b, and 20c generate point light having different color information in different directions at one side of the rotating mirror 10.

That is, having different color information generates light having different wavelength bands, and each light source light source 20: 20a, 20b, 20c is, for example, R (Red, 20a), G (Green, 20b), It may be made of a high-brightness LED or a laser diode (LD) configured to generate light of B (Blue, 20c) color, respectively.

In addition, a condensing lens 21 for condensing light from each light source 20: 20a, 20b, 20c is provided between each light source 20: 20a, 20b, 20c and the rotary mirror 10.

The light collected through the condenser lens 21 is emitted to the same optical axis by the light filtering means 30.

That is, the optical filtering means 30 converts the optical path of the point light generated from each of the light sources 20: 20a, 20b, and 20c incident in different directions and emits the same optical axis to the cylindrical lens 22 described later. Incident.

To this end, the light filtering means 30 may be a filter or a beam splitter.

At this time, it is most efficient to configure the transmittance and reflectance of the first light filtering means 31 and the second light filtering means 32 as shown in FIG.

The point light emitted by the light filtering means 30 on the same optical axis is converted into linear light through the cylindrical lens 22.

On the other hand, the optical path recognition means 40 receives the light reflected from the reflecting surface of the rotating multi-face mirror to recognize the optical path to generate a synchronization signal.

To this end, the optical path recognition means 40 includes an optical path conversion mirror 41, a light receiving sensor 42, and a light receiving driver 43.

The optical path changing mirror 41 converts the path of the light reflected from the reflecting surface of the rotating polygon mirror 10.

The light receiving sensor 42 receives the light reflected through the optical path changing mirror 41 and recognizes the optical path of the light reflected from the reflecting surface of the rotating multifaceted mirror 10.

The light receiving driver 43 generates a signal, i.e., a synchronizing signal, indicating that the reflected light on one reflective surface is terminated based on the detection signal from the light receiving sensor 42.

The control means 50 controls the period and phase of the straight stripes by adjusting the blinking period of each light source 20: 20a, 20b, 20c in synchronization with the synchronization signal generated from the optical path recognition means 40.

That is, the control means 50 controls the light output on / off time of each light source 20: 20a, 20b, 20c through the time control driver 51, so that the period of the straight stripe pattern light irradiated to the measurement object P. Adjust phase with.

In addition, the control means 50 is configured to control the rotation speed of the rotating mirror 10 as well as the flashing period of the light sources 20: 20a, 20b, 20c.

The time control driver 51 is based on the main clock signal generated by the control means 50 during one period of the synchronization signal generated by the light receiving driver 43, and the respective light sources 20: 20a, 20b, Generates a flashing drive signal (VIDEO) to flash 20c).

For example, as shown in FIG. 8, the phase 0 ° is irradiated with the R (Red) color pattern, the phase 120 ° with the G (Green) color pattern, and the phase 240 ° with the B (Blue) color pattern.

After forming pattern light having different color information according to each phase in this way, the surface image of the measurement object P is captured by the color camera 60.

The color camera 60 separates the color information from the light reflected from the surface of the workpiece and combines the color information into a single image.

Therefore, the present invention simultaneously project pattern light having a different color for each phase on the surface of the workpiece P, and image it with the color camera 60.

Here, since the laser passes once in the space where the color camera 60 is imaging every time one of the rotating mirrors 30 reflects, the color camera 60 only passes for a time when the laser beam passes once. ), But if the amount of light is not sufficient, the color camera 60 is exposed while the laser passes several times.

Therefore, the exposure time of the color camera 60 should be matched with the synchronization signal from the optical path recognition means 40.

That is, the start point and the end point of the exposure time of the color camera 60 should coincide with the synchronization signal from the optical path recognition means 40.

Then, the color camera 60 separates images of different colors for each phase from the captured image and combines them into one image to obtain a moire fringe.

That is, in the related art, it is necessary to project the phase shifted pattern light several times for acquiring the moire pattern, and to acquire the images each time the pattern light is projected, and then combine a plurality of the acquired images. The present invention can improve the measurement speed by simultaneously irradiating patterned light having different phases and different color information, and imaging them at once with a color camera to obtain a moire fringe.

Hereinafter, a brief description of the operation using the 3D scanner of the present invention.

First, light is generated from each of the light sources 20: 20a, 20b, and 20c provided on one side of the rotating mirror mirror 10, and the rotating mirror mirror 10 is rotated at high speed to reflect light incident on the reflecting surface.

That is, when each light source 20: 20a, 20b, 20c is turned on, light generated from the light source is collected through the condenser lens 21, and then passes through the light filtering means 30 to the cylindrical lens 22 with the same optical axis. Incident.

Then, the point light incident on the same optical axis is converted into linear light in the cylindrical lens 22 and is incident on the reflecting surface of the rotating polygon mirror 10 and then reflected through the reflecting surface.

Then, the light reflected from the reflecting surface of the rotating mirror mirror 10 is received by the light receiving sensor 42.

Then, the light receiving sensor 42 receives light that is continuously reflected from the reflecting surface of the rotating polyhedron, recognizes the received light path, and generates a synchronization signal.

The time control driver 51 adjusts the flashing period of each light source 20: 20a, 20b, 20c to have a predetermined period and phase in synchronization with the synchronous signal.

At this time, the blinking period of each light source 20: 20a, 20b, 20c is described with reference to FIG. 8, where phase 0 'is a R (Red) color pattern, phase 120 is a G (Green) color pattern, and a phase 240 kHz allows to generate a B (Blue) color pattern. Here, the color examples for each phase are merely examples and may be modified in other ways.

Then, pattern light of various colors having a predetermined period and phase for each color is projected onto the measurement object P surface.

Then, the pattern light reflected from the surface of the measurement object P is picked up by the color camera 60.

At this time, it is preferable that the start point and end point of the exposure time of the color camera 60 coincide with the synchronization signal from the optical path recognition means 40.

Subsequently, each color may be separated from an image captured by the color camera 60 to obtain an image at phase 0 °, an image at phase 120 °, and an image at phase 240 °.

Using these three separate images, moire patterns are obtained.

For example, if each of the light sources 20: 20a, 20b, and 20c are R, G, and B colors, respectively, and flashed by the timing chart in Fig. 7, the R component, G in the image photographed by the color camera 60 is shown. The component and B component correspond to the image at phase 0 degrees, the image at phase 120 degrees, and the image at phase 240 degrees, respectively.

9 is an image obtained with a color camera that the pattern light synthesized with the R, G, and B components is projected onto the measurement object in the present invention.

As described above, the present invention is a light source having different color information to irradiate the measurement object with a combination of one-dimensional pattern light in a variety of colors, and then to take a color camera to separate the image for each color and calculate the existing moire pattern According to the method, the moire pattern can be obtained at a time, thereby reducing the time required for measuring the three-dimensional shape.

1 is a conceptual diagram showing an embodiment of a conventional 3D scanner.

FIG. 2 is a two-dimensional patterned light projected by FIG. 1. FIG.

3 is a conceptual diagram showing another embodiment of the conventional 3D scanner.

4 is a one-dimensional patterned light projected by FIG.

5 is a timing chart of light source blinking in a 3D scanner according to the prior art.

6 is a 3D scanner configuration using a rotating mirror according to the present invention.

7 is a light source flashing timing chart in a 3D scanner using a rotating polyscopy according to the present invention.

8 is a graph of the most effective transmittance-reflectance scheme of the light filtering means for each light source of FIG. 6;

9 is a view showing a moire fringe obtained according to the present invention.

FIG. 9 is an image obtained by a color camera that pattern light in which R, G, and B components are synthesized is projected onto a measurement object according to the present invention.

<Description of the symbols for the main parts of the drawings>

10: rotating face mirror

20: light source

20a: R

20b: G

20c: B

21 condensing lens

22: cylindrical lens

30: light filtering means

31: first optical filtering means

32: second optical filtering means

40: optical path recognition means

41: optical path mirror

42: light receiving sensor

43: light receiving driver

50: control means

51: time control driver

60 color camera

Claims (3)

In the 3D scanner, A rotating multi-face mirror 10 having a plurality of reflective surfaces and rotating at a constant speed to allow light to be incident on the surface of the workpiece P in the form of pattern light of a predetermined period; It is provided on one side of the rotating multi-face mirror Point light with different color information Causing A plurality of light sources 20 , An optical filtering means 30 for emitting light in various directions generated from the respective light sources with a rotating polyhedron at the same optical axis; Optical path recognition means (40) for receiving pattern light reflected from the reflecting surface of the rotating multi-face mirror and recognizing the optical path to generate a synchronization signal; Control means (50) for controlling the period and phase of the straight stripes by adjusting the blinking period of the light source in synchronization with the synchronization signal generated from the optical path recognition means; The start point and the end point of the exposure time coincide with the synchronization signal generated by the optical path recognition means, and include a color camera 60 for capturing light reflected from the surface of the measurement object. 3D scanner used. delete delete

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