KR101175780B1 - 3-Dimension depth camera using the Infrared laser projection display - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional depth camera using an infrared laser display, comprising: a laser generator for transmitting a laser beam of a specific wavelength band to a subject having a uniform light intensity, and scanning the laser beam transmitted from the laser generator to the subject. And an optical scanner for changing the path of the laser light, and an imaging module for receiving the laser light reflected from the surface of the subject, obtaining depth information of the surface of the subject as analog image information, and converting the analog image information into digital image information. And a control unit for controlling the operation of the laser generator and the optical scanner.
According to the three-dimensional depth camera using the infrared laser display according to the present invention, there is an advantage that can provide a three-dimensional stereoscopic image of a precise subject by irradiating a laser light having a uniform light density to the subject.

Description

3-Dimension depth camera using the Infrared laser projection display}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 3D depth camera using an infrared laser projection display, and more particularly, to a three dimensional depth camera using an infrared laser projection display having low cost, low power consumption, and small size.

Generally, 3D image information is composed of geometry (color) information and color (color) information. Shape information may be obtained using a depth image. As a method of acquiring a depth image, there are a method of acquiring directly through a hardware device such as a depth camera, and a method of acquiring indirectly through software image processing called computer vision technology.

In the conventionally known method for acquiring a depth image of a depth camera, it is widely used to measure a time of flight (TOF) in which irradiated light is reflected back to an object. The method of measuring time of flight (TOF) uses a very sensitive device such as a SPAD to detect the moment when the reflected light reaches the light receiving unit and to measure the TOF by using a direct method and a photodiode. There is an indirect method of detecting and calculating the phase difference as the amount of charge when the pulsed light modulated using the?

In the indirect method, the maximum measurement distance increases when using light having a large pulse width, but the depth image is lowered, and when the light having a smaller pulse width is used, the depth image is high, but There is a disadvantage that the measuring distance becomes short.

Meanwhile, a three-dimensional camera using structured light is a variation of a stereo camera. Unlike a stereo camera using two identical cameras, one of the three cameras is connected to a beam projector. The same projection means is used instead of the configuration. In such a structured light camera system, an object is irradiated with a scanning line using a projection means, and then an object irradiated with the scanning line is photographed by using an image photographing means such as a camera, and the obtained scanning line is analyzed to obtain 3D information. You get

As described above, a device for measuring a three-dimensional shape of an object using an optical method is generally called a 3D scanner. The three-dimensional scanner is composed of an image acquisition unit consisting of a lens and a camera, a scanning line light projection unit for projecting the scanning line light, and a computer for analyzing and processing the image acquired through the scanning line light projection unit.

Conventional 3D scanners are composed of an image acquisition unit consisting of a lens and a camera, and a scanning line light projection unit projecting the scanning line light onto the surface of the workpiece. Here, the scanning line light projection unit uses an LCD or a digital light processing (DLP) method as a digital scanning line light projector.

When using the digital scanning line light projector, various colors and various types of scanning line light projections are possible through the combination of R (Red), G (Green), and B (Blue) colors. Such a digital scanning line projector has to input two-dimensional image data.

Therefore, in three-dimensional shape measurement, which projects only one-dimensional scan line, two-dimensional image data must be processed, so that the amount of data increases, and thus, shape measurement takes a lot of time, is expensive, and the volume of equipment is high, There is a problem of power consumption and heat generation.

 In addition, since the intensity of the scan line light irradiated onto the surface of the workpiece is not evenly irradiated on the entire surface of the workpiece, it is difficult to accurately measure the surface shape.

An object of the present invention is to provide a 3D depth camera using an infrared laser display that can accurately measure a subject by irradiating a uniform light onto the subject.

3D depth camera using an infrared laser display according to the present invention for achieving the above object is a laser generator for transmitting a laser light of a specific wavelength band to a subject having a uniform light intensity, and is emitted from the laser generator An optical scanner that changes the path of the laser light to scan the laser light into a subject, and receives laser light reflected from the surface of the subject to obtain depth information of the surface of the subject as analog image information, and converts the analog image information into digital image information. And a control unit for controlling the operation of the laser generator and the optical scanner.

The laser generator transmits laser light of an infrared wavelength band, and the photographing unit further includes a band pass filter for passing only a wavelength band of the laser light emitted from the laser generator, and the optical scanner includes a first mirror and a second mirror. And a driving unit including a reflecting member and a first motor and a second motor for rotating the first mirror and the second mirror, respectively, wherein the first mirror receives the laser light that is discontinuously incident from the laser generator. Reflecting in the second mirror direction, and by rotating the first motor to form a scan line of a pattern arranged in a plurality of laser light spaced apart at a minute interval, the second mirror reflects the scanning line in the direction of the subject The scan of the pattern is arranged by being rotated by the rotation of the second motor spaced apart from each other at a small interval of the plurality of scan lines It allows to form a surface.

According to the 3D depth camera using the infrared laser display according to the present invention, there is an advantage that can implement a three-dimensional stereoscopic image of a precise subject by irradiating a laser light having a uniform light density to the subject.

2 is a block diagram showing the components of a three-dimensional depth camera using an infrared laser display according to the present invention,
3 is an exploded perspective view showing a process of scanning the laser light of the three-dimensional depth camera using the infrared laser display according to the present invention,
4 is a plan view shown;
5 is a plan view shown.

Hereinafter, a three-dimensional depth camera using an infrared laser display according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in more detail.

1 shows a three dimensional depth camera using an infrared laser display.

The 3D depth camera using the infrared laser display according to the present invention includes a laser generator 100, an optical scanner 200, a photographing unit 300, an image processing unit and a central control unit 400.

The laser generator 100 irradiates the laser light 110 of the infrared wavelength band, which is a non-visible region, to the subject 600 at a uniform light density and intensity, and blinks at a predetermined period according to a control signal of the central controller 400 which will be described later. do.

The optical scanner 200 causes the laser light 110 transmitted from the laser generator 100 to be discontinuously incident on the surface of the subject, and includes a reflective member, a driver 220, and an optical member (not shown).

The reflective member includes a first mirror 211 having a plurality of reflecting surfaces and a second mirror 212 having at least one reflecting surface, and the driving unit 220 includes a first mirror for rotating the first mirror 211. A second motor 222 for rotating the motor 221 and the second mirror 212 is provided.

In the present exemplary embodiment, the first mirror 211 is installed to be rotated about the Y axis as illustrated in FIG. 2, and the second mirror 212 is installed to be rotated about the X axis. The direction of the rotation axis of the first mirror 211 and the second mirror 212 is not limited to the illustrated example and may be variously changed.

The first mirror 211 changes the path of the laser light 110 transmitted from the laser generator 100 in the direction (Z-axis direction) of the second mirror 212, and the laser transmitted from the laser generator 100. It is rotated about an X axis direction parallel to the path of the light 110.

The first mirror 211 reflects in the direction of the second mirror 212 when the laser beam 110 transmitted from the laser generator 100 with a predetermined period is incident.

The laser light 120 reflected on the first mirror 211 (hereinafter referred to as 'first reflection light') includes a plurality of first reflection lights 120 having different propagation paths as the first mirror 211 is rotated. Each of the first reflection lights 120 is formed to form a scanning line 140 spaced apart from each other at a minute interval. That is, a plurality of first reflected light 120 forms a pattern arranged discontinuously to form a straight line.

The second mirror 212 reflects the first reflection lights 120 in the direction of the subject 600 when a plurality of discontinuous first reflection lights 120 reflected on the first mirror 211 are incident.

The plurality of first reflection lights (hereinafter referred to as 'second reflection lights') 130 reflected by the second mirror 212 are reflected in the direction of the subject 600 as the second mirror 212 is rotated, and thus a plurality of scans. Lines 140 are scanned on the surface of the subject 600. In other words, each of the scanning lines 140 reflected by the rotation of the second mirror 212 forms a scanning plane having a structure that is spaced apart from each other at minute intervals, and a portion of the scanning plane is scanned on the surface of the subject. .

The optical member (not shown) focuses the laser beam 110 reflected by the reflecting member to focus the laser beam 110 irradiated onto the subject so that the light spot of the laser beam emitted from the laser generator is reduced. Lenses or focusing lenses.

The optical scanner is not limited to the above-described structure, and scans and reflects light in a display field or a predetermined screen area that implements an image by scanning light incident from a light source that emits a laser to a predetermined screen area. It is also possible to apply an optical scanner such as a mirror or scanner having a microstructure commonly used in the scanning field for receiving the received light and reading image information.

The photographing unit 300 includes an imaging module and a band pass filter.

The imaging module 310 is an image pickup device for acquiring an analog image signal by receiving light reflected from an object to be photographed like a conventional digital camera, and an ADC for converting an analog image signal output from the image pickup device into a digital image signal. and a video signal processing module for processing digital video data. Imaging devices constituting the imaging module 310 may employ a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS) sensor used as a conventional image sensor.

In the imaging module 310, a portion of the scanning plane 150 formed by the plurality of scanning lines 140 is scanned on the surface of the subject 600 and reflected from the surface of the subject 600 (hereinafter referred to as 'third reflective light'). 160 to obtain depth information of the surface of the subject 600 in the form of electrical image information.

Here, since the scanning plane 150 has a pattern in which a plurality of laser lights 110 are arranged in a matrix form, the scanning plane 150 may scan laser light 110 having the same light density or light intensity on the surface of the subject 600. The image pickup device may receive a plurality of third reflection lights 160 having different light intensities according to the surface shape of the subject 600 to obtain depth information of the surface of the subject 600 in the form of analog image information.

The band pass filter passes only the wavelength band of the laser light transmitted from the laser generator 100, and blocks the light of the remaining band except the infrared wavelength band when the laser light 110 transmitted from the laser generator 100 is infrared light. .

Alternatively, the bandpass filter may be omitted. In this case, it is preferable to apply the image pickup device only to the laser light in the infrared wavelength band.

The central controller 400 operates the laser generator 100 at regular intervals through the pulse generator, that is, the laser light is transmitted from the laser generator 100 at regular intervals, and the first motor 221 and the second motor 222. To control the rotation speed and operation.

For example, the first motor 221 is rotated so that the laser beam 110 transmitted from the laser generator 100 is reflected on all of the reflective surfaces of the first mirror 211, so that the scan line 140 is the second mirror ( The second motor 222 is controlled to be rotated only after the scanning line 140 is reflected by the second mirror 212 without rotating the second motor 222 until reaching 212.

The three-dimensional depth camera using the infrared laser display according to the present invention as described above has been described with reference to the embodiment shown in the drawings, but this is only illustrative, and those skilled in the art from this It will be understood that various modifications and equivalent embodiments are possible.

Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

100: laser generator 110: laser light
120: first reflection light 130: second reflection light
140: scanning line 150: scanning plane
160: third reflection light 200: optical scanner
211: first mirror 212: second mirror
220: driving unit 300: recording unit
400: central control unit

Claims (2)

A laser generator for transmitting laser light of a specific wavelength band to a subject having a uniform light intensity;
An optical scanner for changing a path of the laser light to scan the laser light transmitted from the laser generator to a subject;
A photographing unit having an imaging module configured to receive laser light reflected from the surface of the subject, obtain depth information of the subject surface as analog image information, and convert the analog image information into digital image information;
And a controller for controlling the operation of the laser generator and the optical scanner. 3D depth camera using an infrared laser display. The method of claim 1,
The laser generator emits laser light in the infrared wavelength band,
The photographing unit further includes a band pass filter for passing only a wavelength band of the laser beam transmitted from the laser generator,
The optical scanner includes a reflective member including a first mirror and a second mirror, and a driving unit including a first motor and a second motor to rotate the first mirror and the second mirror, respectively,
The first mirror reflects a laser beam that is discontinuously incident from the laser generator in the second mirror direction, and scan lines of a pattern in which a plurality of laser beams are spaced at minute intervals by rotation of the first motor. Formed,
The second mirror reflects the scan line in the direction of the subject, but is rotated by the rotation of the second motor to form a scan plane of a pattern in which a plurality of the scan lines are spaced apart at minute intervals. 3D depth camera with infrared laser display.

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