KR102472217B1 - Light transmission apparatus and tof module using the same - Google Patents

Abstract

A TOF module and an optical transmission device thereof are disclosed. The TOF module according to the present invention is a TOF module that measures distance and depth information using a Time Of Flight (TOF) method, and includes a light source including a plurality of emitters outputting infrared light and copying the light output from the emitter. a light transmission unit including a pattern duplication unit for outputting the output; and a light receiving unit configured to receive light output from the light transmitting unit and reflected on the subject, and the light source drives the emitter to output a plurality of light patterns.

Description

Optical transmission device and ToF (Time of Flight) module using the same {LIGHT TRANSMISSION APPARATUS AND TOF MODULE USING THE SAME}

The present invention relates to an optical transmission device and a ToF (Time of Flight) module using the same, and more particularly, to a Time Of Flight (TOF) method that measures distance and depth information on a subject while increasing resolution, and provides a necessary electronic circuit. A TOF module capable of reducing the volume and cost by minimizing the number and an optical transmission device thereof.

Methods for obtaining distance information and depth information on a subject include a stereo method, a structured light method, a time of flight (TOF) method, and the like.

The stereo method is a method of obtaining distance and depth information using two cameras, and has a problem in that the acquisition speed of distance and depth information is slow because many calculations are required to find the distance.

In addition, the structured light method is a method of calculating distance by radiating structured light, such as a visible light laser or an infrared laser, to an object, and acquiring the reflected light as a camera image to analyze distortion according to the distance of the object. However, since the image according to the structured light method is greatly affected by ambient lighting such as sunlight or the brightness of fluorescent lamps, there is a problem in that the resultant object distance and depth information are sensitive to lighting noise.

On the other hand, the TOF method is a method of obtaining distance and depth information by emitting waves such as ultrasonic waves or electromagnetic waves to a subject and measuring the time until they are reflected back.

However, since the device for measuring distance and depth information based on TOF requires a precise electronic circuit such as a capacitor for each pixel, the resolution is lower than that of a general RGB image sensor of the same size because the size is larger than that of a general RGB image sensor. .

In addition, since a device for measuring distance and depth information based on TOF requires an electronic circuit for each pixel, it is bulky and expensive.

The present invention was devised to solve and improve the above-mentioned problems, and the TOF method can measure distance and depth information on a subject using the TOF method, increase resolution, and reduce volume and cost by minimizing the number of electronic circuits required. It is an object of the present invention to provide a module and an optical transmission device thereof.

A TOF module according to an aspect of the present invention for achieving the above object is a TOF module for measuring distance and depth information using a Time Of Flight (TOF) method, comprising a plurality of emitters outputting infrared light a light transmission unit including a light source and a pattern duplication unit for duplicating and outputting light output from the emitter; and a light receiving unit configured to receive light output from the light transmitting unit and reflected on a subject, and the light source drives the emitter to output a plurality of light patterns.

Here, the light source sequentially emits light of different patterns.

Also, the emitters driven to output the different patterns do not overlap each other.

The pattern copying unit includes a lens array composed of a plurality of micro lenses, and copies the light pattern emitted from the light source through the micro lenses.

The light transmitting unit may further include a divergence angle enlarger configured to enlarge a divergence angle of the light emitted by the light source, and the pattern replica unit copies a light pattern having a divergence angle enlarged by the divergence angle enlarger.

The light transmission unit may further include a view angle enlargement unit for enlarging the view angles of the light patterns copied by the pattern duplication unit.

The light source may drive the emitter in a pattern pattern including at least one of a spot and a stripe.

A light transmission device for achieving the above object is mounted on a TOF module and emits light to a subject, comprising: a light source that emits light in a plurality of patterns by driving at least one emitter; a pattern copying unit duplicating each of the patterns; and a light output unit configured to output light from which each of the patterns has been copied by the pattern replica unit to the subject.

The above-described light transmission device includes a divergence angle enlarger for enlarging a divergence angle of light emitted by the light source; and a view angle enlarger for enlarging the angle of view of the light patterns copied by the pattern copy unit, wherein the pattern copy unit may copy the light pattern whose divergence angle is enlarged by the divergence angle enlarger.

According to the present invention, while measuring distance and depth information based on TOF, light is emitted in a plurality of patterns, and each emitted light pattern is duplicated and transmitted to a subject as many as the number of patterns, thereby increasing resolution.

In addition, according to the present invention, since a plurality of pixels are configured by copying and transmitting light patterns emitted from a light source, as a result, the volume and cost of the TOF module can be reduced by minimizing the number of electronic circuits.

1 is a diagram schematically showing the configuration of a TOF module according to an embodiment of the present invention.
FIG. 2 is a diagram schematically illustrating a configuration example of an emitter of the light source shown in FIG. 1 .
3 is a diagram showing an example of driving an emitter for sequentially emitting light of different patterns.
4 is a view showing a replicated example of a light pattern.
5 is a view showing examples of (a) a divergence angle of an angle emitted by a light source and (b) a divergence angle expanded by a divergence angle enlarger.
6 is a diagram illustrating an example of a view angle enlarger for enlarging a view angle of a light pattern.

Hereinafter, some embodiments of the present invention will be described through exemplary drawings. In describing the reference numerals for the components of each drawing, the same numerals indicate the same components as much as possible, even if they are displayed on different drawings. In addition, in describing an embodiment of the present invention, if it is determined that a detailed description of a related known configuration or function hinders understanding of the embodiment of the present invention, the detailed description will be omitted.

Also, terms such as first, second, A, B, (a), and (b) may be used to describe components of an embodiment of the present invention. These terms are only used to distinguish the component from other components, and the nature, order, or order of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, the element may be directly connected, coupled, or connected to the other element, but not between the element and the other element. It should be understood that another component may be “connected”, “coupled” or “connected” between elements.

1 is a diagram schematically showing the configuration of a TOF module according to an embodiment of the present invention.

Referring to FIG. 1 , a TOF module 100 according to an embodiment of the present invention includes an optical transmitter 110, an optical receiver 120, and a signal processor 130.

The light transmitter 110 transmits light to a subject in order to measure distance information and depth information according to a time of flight (TOF) method. The emitted light may be light in an infrared wavelength region. At this time, the light transmission unit 110 of the TOF module 100 according to an embodiment of the present invention includes a light source 112, a pattern duplication unit 114, a divergence angle expansion unit 116, and a view angle expansion unit 118. .

The light source 112 includes at least one emitter that emits light, and may emit light in various patterns by driving each emitter. The emitter may be disposed while being fixed to the light source 122 . For example, as shown in FIG. 2, the light source 112 includes an emitter (hereinafter, referred to as a 'first emitter') 112-1 at the upper left and an emitter at the upper right (hereinafter, referred to as 'the first emitter'). 2 emitter) (112-2), the lower left emitter (hereinafter referred to as 'third emitter') 112-3, and the lower right emitter (hereinafter referred to as 'fourth emitter') ') (112-4) may be included, and light may be emitted in various patterns by selectively driving at least one emitter among the respective emitters. Each emitter can contain a single emitter or a set of emitters.

Meanwhile, the light source 112 sequentially emits different light patterns according to the driving of the emitter. For example, the light source 112 is any one of the first emitter 112-1, the second emitter 112-2, the third emitter 112-3, and the fourth emitter 112-4. When only one emitter is driven to emit light in four light patterns, the light source 112 is a first emitter 112-1 -> a second emitter 112-2, as shown in FIG. Different light patterns may be sequentially emitted by driving each emitter in the order of -> third emitter 112-3 -> fourth emitter 112-4. At this time, it is preferable that the driving order of each emitter is previously set. In addition, each light pattern may be emitted by the same planar light source, but each light pattern may be distinguished according to a driven emitter. As the light source 112 , a light emitting diode (LED), an edge emitting laser (EEL), a vertical-cavity surface emitting laser (VCSEL), or the like may be used.

Here, although the light source 112 has been shown and described as driving the emitter in a pattern pattern in the form of a spot, the light source 112 drives the emitter in a pattern pattern in the form of a stripe, or It can also be driven by patterns. That is, the shape of the emitter included in the light source 112 may be formed in various shapes according to the shape of the pattern pattern to be implemented, and the pattern pattern may be implemented so that light emitting areas between patterns do not overlap. That is, emitters driven to output different patterns may not overlap each other. Patterns can be sequentially output and repeatedly output. It is possible to increase the resolution of the ToF module by sequentially outputting the emitters constituting the light source without operating them simultaneously.

The pattern copying unit 114 copies each light pattern emitted by the light source 112 . For example, when the light source 112 drives each emitter in the order shown in FIG. 3, the pattern copying unit 114 copies each light pattern 3x3 as shown in FIG. can Here, the copying of each light pattern in a size of 3x3 by the pattern copying unit 114 is only an example to aid understanding, and is not limited to FIG. 4 and the description.

Here, the pattern copying unit 114 may use an optical system such as a Micro Lens Array (MLA) or a Diffractive Optical Element (DOE). For example, in the case of using MLA as the pattern duplicating unit 114, the pattern duplicating unit 114 is composed of a lens array including a plurality of microlenses, and each pattern duplicating unit 114 is as many as the number of microlenses. It is also possible to replicate the light pattern of .

The divergence angle enlarger 116 enlarges the divergence angle of light emitted by the light source 112 . In general, light emitted by the light source 112 has linearity, as shown in FIG. 5(a). In this case, the divergence angle expansion unit 116 expands the divergence angle of light emitted by the light source 112, as shown in FIG. 5(b). Here, the enlargement range of the divergence angle disclosed in (b) of FIG. 5 is only for explaining an example, and is not limited thereto. In this case, the pattern copying unit 114 may enlarge the area of the surface light source formed by the light source 112 by replicating the light pattern of which the divergence angle is enlarged by the divergence angle enlarger 116 . Therefore, it is possible to measure a distance over a wider area than when the divergence angle enlargement unit 166 does not exist.

The field of view magnifying unit 118 enlarges the field of view of the light patterns copied by the pattern copying unit 114 . For example, as shown in FIG. 4 , the pattern copying unit 114 copies each light pattern 3x3, the view angle enlarger 118 enlarges the view angle of each of the duplicated light patterns. To this end, the angle of view enlarger 118 may be implemented as a lens having a shape as shown in FIG. 6 . For example, the angle of view enlargement portion 118 may have a meniscus shape. The angle-of-view enlarger 118 may have both sides concave toward the light source and convex toward the subject. However, the shape of the angle-of-view enlarger 118 is not limited to the illustrated form, and may be implemented with various types of lenses, such as a lens with both sides convex and one side convex and the other side concave.

The light receiving unit 120 receives light reflected from a subject. That is, when the light transmitter 110 emits light toward a subject, some of the light is reflected by the subject, and the light receiver 120 receives light reflected by the subject and returned. The light receiving unit 120 may include a sensor capable of measuring a distance by receiving light reflected from a subject in the form of pulsed infrared rays output from a light source. At this time, since the function and configuration of the light receiving unit 120 are the same as those of the light receiving unit 120 according to known technology, a detailed description thereof is omitted here.

The signal processor 130 processes the light transmitted by the light transmitter 110 and the light received by the light receiver 120 to calculate distance information and depth information. At this time, since the method of calculating the distance information and the depth information by the signal processing unit 130 is the same as that of the known distance measurement technology using ToF, a detailed description thereof is omitted here.

However, in the TOF module according to an embodiment of the present invention, the light source emits light to the subject in various patterns, and the pattern copying unit transmits light by copying the light pattern, thereby providing enlarged image information compared to the conventional TOF module. can be obtained

In addition, since the TOF module according to an embodiment of the present invention can obtain image information corresponding to the same resolution as the conventional TOF module using a sensor with a lower resolution than that of the conventional TOF module, manufacturing cost of the TOF module can be reduced. Not only can it be reduced, but also the overall volume can be reduced because the number of electronic circuits can be reduced.

Embodiments according to the present invention have been described above, but these are merely examples, and those skilled in the art will understand that various modifications and embodiments of equivalent range are possible therefrom. Therefore, the protection scope of the present invention should be defined by the following claims as well as those equivalent thereto.

100: TOF module 110: optical transmission unit (optical transmission device)
112: light source 114: pattern replica unit
116: divergence angle expansion unit 118: angle of view expansion unit
120: light receiving unit 130: signal processing unit

Claims (9)

In the TOF module for measuring distance and depth information using a Time Of Flight (TOF) method,
a light source including a plurality of emitters that output infrared light;
a light transmitting unit including a pattern copying unit for copying and outputting the light pattern output from the emitter; and
A light receiving unit configured to receive light output from the light transmitting unit and reflected on a subject;
The light source drives the emitter to sequentially output a plurality of light patterns,
The plurality of emitters include a first emitter disposed in the upper left corner, a second emitter disposed in the upper right corner, a third emitter disposed in the lower left corner, and a fourth emitter disposed in the lower right corner;
The light source sequentially drives the first to fourth emitters to sequentially emit different light patterns;
The pattern copying unit replicates a light emitting area of light output to the subject in a matrix form,
In the light patterns formed through the first to fourth emitters, light emitting areas between light patterns in the light emitting area formed in the matrix form do not overlap,
The light source drives the emitter with a pattern pattern including at least one of a spot and a stripe.
delete delete According to claim 1,
The pattern duplication unit,
It includes a lens array composed of a plurality of micro lenses,
A TOF module that replicates a light pattern emitted from the light source through the micro lens.
According to claim 1,
The light transmitter,
Further comprising a divergence angle expansion unit for enlarging the divergence angle of the light emitted by the light source,
The TOF module for copying the light pattern of which the divergence angle is enlarged by the divergence angle magnifying unit.
According to claim 1,
The light transmitter,
The TOF module further includes a view angle enlargement unit for enlarging the view angles of the light patterns copied by the pattern duplication unit.
delete In the light transmitting device mounted on the TOF module and transmitting light to a subject,
a light source that emits light in a plurality of patterns by driving a plurality of emitters;
a pattern copying unit duplicating each of the patterns; and
And a light output unit for outputting light from which each pattern is copied by the pattern duplication unit to the subject,
The plurality of emitters include a first emitter disposed in the upper left corner, a second emitter disposed in the upper right corner, a third emitter disposed in the lower left corner, and a fourth emitter disposed in the lower right corner;
The light source sequentially drives the first to fourth emitters to sequentially emit different light patterns;
The pattern copying unit replicates a light emitting area of light output to the subject in a matrix form,
In the light patterns formed through the first to fourth emitters, light emitting areas between light patterns in the light emitting area formed in the matrix form do not overlap,
The light source drives the emitter with a pattern including at least one of a spot and a stripe. According to claim 8,
A divergence angle enlarger for enlarging the divergence angle of the light emitted by the light source; and
It further includes; a view angle enlarger for enlarging the angle of view of the light patterns copied by the pattern copy unit;
The pattern copying unit copies the light pattern of which the divergence angle is enlarged by the divergence angle enlargement unit.

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