CN217305653U - In-line laser projector, camera module, and electronic device - Google Patents

Abstract

The utility model provides an in-line laser projector, a camera assembly and an electronic device. The laser projector includes a substrate assembly, a plurality of laser light sources, and diffractive optical elements. A plurality of laser light sources are arranged on the substrate assembly for emitting laser light, and the plurality of laser light sources are arranged along the set line direction; the diffractive optical element is used for diffusing the laser light emitted by the multiple laser light sources in a direction parallel to the set line direction , to form a linear projection pattern. According to the present invention, the word-line laser projector can easily project a word-line whose light intensity distribution meets preset requirements.

Description

In-line laser projectors, camera assemblies and electronic devices

technical field

The utility model relates to the field of imaging technology, in particular to a laser projector, a camera assembly and an electronic device having the same.

Background technique

With the popularization of structured light, one-line laser projection systems are increasingly used for depth detection and 3D perception in the industrial and consumer electronics industries, which requires narrower width and higher uniformity of the one-line laser. sex and higher brightness. At the same time, the system is becoming more and more miniaturized, and the traditional one-line laser projection system mostly uses a single-mode laser diode (LD) as the light source of the one-line. However, due to the good monochromaticity and coherence of the laser, when the light of the LD irradiates the rough surface of the general object, speckle will be formed on the surface of the object due to the interference of the light, thereby generating a granular structure inside the in-line spot, reducing the The quality of the word line directly affects the calculation results of depth detection and 3D perception. At present, the in-line light output by the conventional in-line laser is difficult to meet the application requirements in terms of divergence angle, spot uniformity, and sharpness of the edge of the spot. In addition, it is also difficult for conventional inline lasers to meet the specific requirements for the energy distribution of the in-line in specific application scenarios.

Therefore, there is a need for an in-line laser projector that can easily realize a preset light intensity distribution (uniform or non-uniform) according to application requirements.

Utility model content

A series of concepts in simplified form have been introduced in the Summary of the Invention, which are described in further detail in the Detailed Description. The utility model content part of the present utility model is not intended to attempt to limit the key features and necessary technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

A first aspect of the present utility model provides an in-line laser projector, which includes:

Substrate assembly;

a plurality of laser light sources, the plurality of laser light sources are arranged on the base plate assembly for emitting laser light, and the plurality of laser light sources are arranged along a set linear direction;

The diffractive optical element is used for diffusing the laser light emitted by the plurality of laser light sources in a direction parallel to the set straight line direction, so as to form a linear projection pattern.

According to the present invention, the diffractive optical element can make the laser light source project a linear projection pattern, and the projection patterns of a plurality of laser light sources will be superimposed on each other and staggered from each other in the set linear direction to form the final linear projection pattern pattern. When using diffractive optical elements to form a line, the energy distribution of the line projection pattern can be easily controlled (eg, uniform or non-uniform), so that the energy distribution of the final projection pattern meets the preset energy distribution requirements.

Optionally, the laser light source is a vertical cavity surface emitting laser element.

In the present invention, the laser light source is a vertical cavity surface emitting laser element, which can make the projector smaller.

Optionally, the number of the laser light sources is 7 to 25, and/or the plurality of laser light sources are generally distributed at equal intervals.

Optionally, the distance between two adjacent laser light sources is 20 μm to 40 μm, and/or the total distribution width of the plurality of laser light sources is 150 μm to 600 μm.

Optionally, the field angle of the in-line projection pattern projected by the laser light emitted by the single laser light source is 40° to 130°.

Optionally, the diffractive optical element is parallel to the substrate assembly, and the air gap between the laser light source and the diffractive optical element is 2 mm to 5.5 mm.

Optionally, the in-line laser projector further includes a collimating mirror, and the collimating mirror is arranged between the laser light source and the diffractive optical element.

Further, it is characterized in that the focal length of the collimating lens is 2 mm to 5.5 mm.

In the present invention, when the diffractive optical element does not have the collimation function, the light emitted by the laser light source is collimated by the collimating mirror.

Optionally, the in-line projection pattern includes transition regions at both ends and a middle region between the two transition regions, and the in-line laser projector is configured such that: the projection of the transition regions The angle is 2° to 8°, and the unevenness of the intensity of the projected light in the intermediate region is less than 30%.

When it is necessary to project a word line with a uniform light intensity distribution, the laser projector according to the present invention can project a word line with a uniform spot and a sharp edge of the spot.

Optionally, the diffractive optical element includes a 2-step, 4-step or 8-step micro-nano structure.

In the present invention, the machining accuracy of the diffractive optical element can meet the projection requirements.

Optionally, the diffractive optical element is configured such that the intensity distribution of the projection light of the in-line projection pattern satisfies a preset intensity distribution curve.

The laser projector according to the present invention can project a word line whose energy distribution meets the preset energy distribution requirements.

Optionally, the in-line projection pattern includes transition regions at both ends and a middle region between the two transition regions, and the in-line laser projector is configured such that: the projection of the middle region The intensity of light is distributed according to the normalized intensity distribution of 1/(cosα) ^a , where a is a real number in the range of (0, 1.5), and α is the diffraction angle of each point on the inline projection pattern.

In a specific embodiment of the present invention, the diffractive optical element is configured such that the light intensity distribution on the line is low in the middle and high at both ends, and the light intensity is distributed according to the normalized intensity distribution of 1/(cosα) ^a .

A second aspect of the present invention provides a camera assembly comprising:

The above-mentioned in-line laser projector;

an image collector for collecting a laser image formed by the pattern projected by the in-line laser projector; and

a processor for processing the laser image to obtain a depth image.

The camera assembly according to the present invention can easily project a word line whose light intensity distribution meets preset light intensity distribution requirements (for example, uniform or non-uniform) according to application requirements, and shoot the laser image formed by the word line. and processing.

A third aspect of the present utility model provides an electronic device, which includes:

shell; and

The camera assembly described above, the camera assembly is provided to and exposed from the housing to obtain a depth image.

The camera assembly according to the present invention can easily project a word line with a light front distribution that meets preset light intensity distribution requirements (for example, uniform or non-uniform) according to application requirements, and shoot and record the laser image formed by the word line. deal with.

Description of drawings

The following drawings of the present invention are incorporated herein as a part of the present invention for understanding of the present invention. The accompanying drawings illustrate the embodiments of the present invention and their description, which are used to explain the principles of the present invention. In the attached image:

1 is a schematic structural diagram of an in-line laser projector according to a first embodiment of the present invention;

2 is a schematic structural diagram of an inline laser projector according to a second embodiment of the present invention;

3 is a schematic diagram of the projection effect of a single laser light source of the in-line laser projector according to the present invention;

4 is a schematic diagram of the projection effect of the in-line laser projector according to the present invention, wherein, for the purpose of illustration, the in-line projection pattern formed by a plurality of superimposed single laser light sources is decomposed in space;

5 is an explanatory diagram of the arrangement of a plurality of laser light sources of an in-line laser projector according to a specific embodiment of the present invention, wherein there are 9 laser light sources;

Fig. 6 is the simulation schematic diagram of the in-line projection pattern projected by the single laser light source of the in-line laser projector of Fig. 5, wherein the projection distance is 300mm;

FIG. 7 is a simulation schematic diagram of the in-line projection pattern projected by the in-line laser projector of FIG. 5 , wherein the projection distance is 300 mm;

Fig. 8 is the energy distribution simulation schematic diagram of the in-line projection pattern projected by the single laser light source of the in-line laser projector in Fig. 5, wherein the energy value is the energy of each diffraction order at infinity;

9 is a schematic diagram illustrating the energy distribution simulation of the in-line projection pattern projected by the in-line laser projector in FIG. 5 , where the energy value is the energy of each diffraction order at infinity.

Description of reference numbers:

10: Substrate assembly

20: Laser light source

25: Laser Beam

30: Diffractive Optical Elements

40: Collimating mirror

50: Projection screen

60: In-line projection pattern of a single laser light source

65: In-line projection pattern superimposed by multiple laser light sources

100: In-line laser projector

Detailed ways

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without one or more of these details. In other instances, some technical features known in the art are not described in order to avoid confusion with the present invention.

For a thorough understanding of the present invention, a detailed description will be set forth in the following description. It should be understood that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of these exemplary embodiments to those skilled in the art. Obviously, the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art. The preferred embodiments of the present invention are described in detail as follows, however, the present invention may have other embodiments in addition to these detailed descriptions.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular forms are also intended to include the plural forms unless the context clearly dictates otherwise. Furthermore, it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, it indicates the presence of features, integers, steps, operations, elements and/or components, but does not preclude the presence or addition of a or multiple other features, integers, steps, operations, elements, components and/or combinations thereof.

The ordinal numbers such as "first" and "second" cited in the present invention are merely identifications, and do not have any other meanings, such as a specific order and the like. Also, for example, the term "first element" does not by itself imply the presence of a "second element," nor does the term "second element" by itself imply the presence of a "first element."

Now, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings.

A first aspect of the present invention provides an in-line laser projector.

As shown in FIG. 1 , in the first embodiment, an inline laser projector 100 includes a substrate assembly 10 , a plurality of laser light sources 20 , and a diffractive optical element 30 (DOE). A plurality of laser light sources 20 are disposed on the substrate assembly 10 for emitting laser light. The plurality of laser light sources 20 are arranged in the predetermined linear direction X. The diffractive optical element 30 is used for diffusing the laser light emitted by the plurality of laser light sources 20 in a direction parallel to the set straight line direction X, so as to form an inline projection pattern. The total distribution width of the plurality of laser light sources 20 is L, and the distance between two adjacent laser light sources 20 is D. It can be understood that the diffractive optical element 30 has its own collimation function.

Preferably, the laser light source 20 is a vertical cavity surface emitting laser element (VCSEL). Of course, the laser light source 20 can also be, for example, an LED laser light source or an edge emitting laser (EEL).

As shown in FIG. 2 , in the second embodiment, the diffractive optical element 30 does not have a collimating function, so the inline laser projector 100 further includes a collimating mirror 40 . The collimating mirror 40 is located between the laser light source 20 and the diffractive optical element 30 for collimating the laser beam emitted by the laser light source 20 .

As shown in FIG. 3 , one of the laser light sources 20 of the inline laser projector 100 can emit a laser beam 25 . The laser beam 25 forms an inline projection pattern 60 on the projection screen 50 after passing through the diffractive optical element 30 . In other words, the diffractive optical element 30 is configured to diffuse the laser light emitted by the laser light source 20 in an inline shape. The word line is diffused along the set linear direction X. The field of view (FOV) of the in-line projection pattern 60 projected by the laser light emitted by a single laser light source 20 is θs, and there is an air gap G between the laser light source 20 and the diffractive optical element 30 .

As shown in FIG. 4 , when the in-line laser projector 100 includes a plurality of laser light sources 20 arranged at intervals along the set linear direction X, each laser light source 20 forms its own in-line projection pattern 60 . The in-line projection patterns 60 are spatially superimposed to form a superimposed in-line projection pattern 65 . The multiple in-line projection patterns 60 are mutually displaced in the set linear direction X, so that the superposition result is similar to extending the in-line projection patterns 60 of a single laser light source 20 in the set linear direction X. The field of view (FOV) of the in-line projection pattern 60 projected by the laser emitted by a single laser light source 20 is θs, and the in-line projection pattern 60 formed by the superposition of the in-line projection patterns 60 of the multiple laser light sources 20 The pattern 65 has a field angle θf, θf>θs. It can be understood that the larger the total distribution width L of the plurality of laser light sources 20 is, the larger the field angle θf of the one-line projection pattern 65 is.

The light intensity distribution characteristic of the inline projection pattern 60 or 65 is controlled by the diffractive optical element 30 . The diffractive optical element 30 may be configured to make the light intensity distribution of the inline projection pattern 60 as uniform as possible. As shown in FIG. 4 , the plurality of in-line projection patterns 60 are staggered from each other in the set linear direction X, so that in the superimposed in-line projection patterns 65 , the relatively middle part participates in the superimposed single-line projection pattern 65 . The number of the word line type projection patterns 60 is large, and the number of the single word line type projection patterns 60 participating in the superposition at the portions located at opposite ends is small. Therefore, the light intensity distribution curve C of the superimposed one-line projection pattern 65 is substantially trapezoidal. As shown in FIG. 4 , the one-line projection pattern 60 includes transition regions at both ends (the viewing angle of the transition region is θb) and a middle region located between the two transition regions (the viewing angle of the middle region is θu) , the light intensity of the middle area (the number of the single inline projection patterns 60 participating in the superposition is large) is higher than that of the transition area (the number of the individual inline projection patterns 60 participating in the superposition is small), the middle area The light intensity is basically uniformly distributed, and the light intensity in the transition area is smaller as it is closer to both ends. Among them, each field of view has the following quantitative relationship:

θb=arctg(L/G),

θf=θs+θb,

θu=θs−θb.

In the embodiment shown in FIG. 2 , θb=arctg(L/f), where f is the focal length of the collimating lens 40 . Preferably, the focal length f of the collimating lens 40 is 2 mm to 5.5 mm.

In the present invention, preferably, the in-line laser projector 100 is configured such that the projection angle of the transition area (ie the viewing angle θb) is 2° to 8°, and the intensity of the projection light in the middle area is The non-uniformity is less than 30%.

As shown in FIGS. 5 to 9 , in the specific embodiment in which the in-line laser projector 100 includes nine laser light sources 20 , the nine laser light sources 20 are distributed at equal intervals, and the total distribution width L is 500 μm (see FIG. 5 ) . The air gap G between the laser light source 20 and the diffractive optical element 30 is 5 mm. The field angle θs of the in-line projection pattern 60 projected by the laser light emitted by the single laser light source 20 is 120° (see FIG. 6 ). The light intensity (energy) distribution of the in-line projection pattern 60 projected by the laser light emitted by a single laser light source 20 is shown in FIG. 8 . After the projection lights of the nine laser light sources 20 are superimposed, comparing FIG. 6 with FIG. 7 , it can be seen that the field angle of the superimposed one-line projection pattern 65 is significantly larger than 120°. The light intensity (energy) distribution of the superimposed one-line projection pattern 65 is shown in FIG. 9 . Comparing Figure 8 with Figure 9, it can be seen that the uniformity of light intensity after multi-point stacking is significantly improved. The line width opening angles of the in-line projection patterns 60 and 65 are less than 0.05°.

In practical applications, the camera usually shoots a line at a close distance (eg, within 10m). In this case, since the light spot itself has a certain size, the adjacent signal points on a word line will be superimposed so as to have the effect of mutual convolution. Convolution will make the light intensity of each signal point on the received word line more uniform. Therefore, in practice, the non-uniformity of a word line received at close range is much lower than that of a word line projected at infinity (eg, the simulation result shown in FIG. 9 ). For example, in the embodiments shown in FIGS. 5 to 9 , in the case of close-range reception, the field angle θb of the transition area is 5.7°, and the non-uniformity of the intermediate area is less than 30%.

In the present utility model, the calculation method of light intensity non-uniformity is:

(maximum light intensity - minimum light intensity)/(maximum light intensity + minimum light intensity).

In the present invention, preferably, the number of laser light sources 20 is 7 to 25. Preferably, the plurality of laser light sources 20 are distributed at equal intervals. Or the plurality of laser light sources 20 are distributed at substantially equal intervals. Preferably, the distance D between two adjacent laser light sources 20 is 20 μm to 40 μm. Preferably, the total distribution width L of the plurality of laser light sources 20 is 150 μm to 600 μm. Preferably, the field angle θs of the in-line projection pattern 60 projected by the laser light emitted by the single laser light source 20 is 40° to 130°. Preferably, the diffractive optical element 30 is parallel to the substrate assembly 10 , so that the distances between the plurality of laser light sources 20 and the diffractive optical element 30 are equal. Preferably, the air gap G between the laser light source 20 and the diffractive optical element 30 is 2 mm to 5.5 mm. Preferably, the diffractive optical element 30 includes a 2-step, 4-step or 8-step micro-nano structure.

The diffractive optical element 30 may also be configured such that the intensity distribution of the projection light of the in-line projection pattern 65 satisfies a preset intensity distribution curve. In addition to the above-mentioned form of uniform distribution, for example, the intensity distribution of the projection light of the in-line projection pattern 65 can be the normalized intensity distribution of 1/(cosα) ^a in the middle region, where a is the value range of ( 0, 1.5), and α is the diffraction angle corresponding to each point on the line.

Therefore, the word line type laser projector according to the present invention can easily realize the preset light intensity distribution (eg, uniform or non-uniform) of the word line according to application requirements.

A second aspect of the present invention provides a camera assembly. In a preferred embodiment, the camera assembly includes the above-mentioned in-line laser projector 100, an image collector and a processor. Wherein, the image collector is used to collect the laser image formed by the pattern projected by the in-line laser projector 100; the processor is used to process the laser image to obtain the depth image. The camera assembly according to the present invention can easily project a word line whose light intensity distribution meets preset light intensity distribution requirements (for example, uniform or non-uniform) according to application requirements, and shoot the laser image formed by the word line. and processing.

A third aspect of the present invention provides an electronic device. In a preferred embodiment, the electronic device includes a housing and a camera assembly as described above. Therein, the camera assembly is provided to and exposed from the housing to obtain depth images. The electronic device is, for example, a mobile phone, a wristband, a watch, a tablet computer, a smart glasses, a smart helmet, a somatosensory game device, and the like. The electronic device according to the present invention can easily project a word line whose light intensity distribution meets the preset light intensity distribution requirements (for example, uniform or non-uniform) according to application requirements, and shoot the laser image formed by the word line. and processing.

Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the present invention. The terms used herein are for the purpose of describing specific implementations, and are not intended to limit the present invention.

The present invention has been described by the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of illustration and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, those skilled in the art can understand that the present invention is not limited to the above-mentioned embodiments, and more variations and modifications can also be made according to the teachings of the present invention, which all fall within the scope of the present invention. within the scope of protection.

Claims (14)

1. A linear laser projector comprising:

a substrate assembly;

a plurality of laser light sources provided on the substrate assembly for emitting laser light, the plurality of laser light sources being arranged in a set linear direction;

and the diffraction optical element is used for diffusing the laser emitted by the plurality of laser light sources along a direction parallel to the set linear direction so as to form a linear projection pattern.

2. The inline laser projector of claim 1, wherein the laser light source is a vertical cavity surface emitting laser element.

3. The inline laser projector of claim 1, wherein the number of laser light sources is 7 to 25 and/or the plurality of laser light sources are generally equally spaced.

4. The inline laser projector of claim 1, wherein two adjacent laser light sources are at a distance of 20 to 40 μ ι η and/or the total width of the distribution of the plurality of laser light sources is 150 to 600 μ ι η.

5. The inline laser projector of claim 1 wherein the laser light emitted by a single laser light source projects an inline projection pattern with a field angle of 40 ° to 130 °.

6. The inline laser projector of claim 1, wherein the diffractive optical element is parallel to the substrate assembly and the air gap between the laser light source and the diffractive optical element is 2mm to 5.5 mm.

7. The inline laser projector of claim 1, further comprising a collimating mirror disposed between the laser light source and the diffractive optical element.

8. The inline laser projector of claim 7, wherein the collimating mirror has a focal length of 2mm to 5.5 mm.

9. The inline laser projector of any one of claims 1 to 8, wherein the inline projection pattern includes transition regions at both ends and a middle region between the two transition regions, the inline laser projector being configured such that: the projection angle of the transition region is 2 ° to 8 °, and the unevenness of the intensity of the projected light of the intermediate region is less than 30%.

10. The inline laser projector of any one of claims 1 to 8, wherein the diffractive optical element comprises a 2-step, 4-step or 8-step micro-nano structure.

11. The inline laser projector of any one of claims 1 to 8, wherein the diffractive optical element is configured such that the intensity distribution of the projected light of the inline projection pattern satisfies a preset intensity distribution curve.

12. The inline laser projector of claim 11, wherein the inline projection pattern includes transition regions at both ends and an intermediate region between the two transition regionsThe inline laser projector is configured such that: the intensity of the projected light in the middle area is 1/(cos alpha) ^a Wherein a is a real number with a value range of (0, 1.5), and α is a diffraction angle of each point on the collinear projection pattern.

13. A camera assembly, comprising:

the inline laser projector of any one of claims 1-12;

the image collector is used for collecting a laser image formed by the pattern projected by the linear laser projector; and

a processor for processing the laser image to obtain a depth image.

14. An electronic device, comprising:

a housing; and

the camera assembly of claim 13, disposed to and exposed from the housing to obtain a depth image.

Images