Surface-emitting laser device and camera module

Abstract

A surface-emitting laser element disclosed in an embodiment of the invention comprises a first emitting portion having a plurality of first emitters arranged therein; and a second emitting portion having a plurality of second emitters arranged therein, wherein the first emitting portion emits a first beam angle and the second emitting portion emits a second beam angle narrower than the first beam angle, and the first emitters and the second emitters may be alternately arranged in at least one direction.

Description

Technology Field

[0001] An embodiment of the invention relates to a surface-emitting laser element and a camera module having the same. Background Technology

[0002] Camera modules perform the function of capturing objects and saving them as images or videos, and are being installed in various applications. In particular, camera modules are manufactured to be ultra-compact, allowing them to be applied to portable devices such as smartphones, tablet PCs, and laptops, as well as mobile vehicles such as drones and automobiles.

[0003] Recently, the demand and supply for 3D content have been increasing. Accordingly, various technologies capable of perceiving 3D content by obtaining depth information using cameras are being researched and developed. For example, technologies capable of obtaining depth information include technologies using stereo cameras, technologies using structured light cameras, technologies using DFD (Depth from defocus) cameras, and technologies using TOF (Time of flight) camera modules.

[0004] First, the technology using stereo cameras is a technique that generates depth information by utilizing differences in distance, spacing, etc., arising from the left-right parallax of images received through multiple cameras, such as cameras positioned on the left and right.

[0005] In addition, technology using structured light cameras is a technique that generates depth information by utilizing light sources arranged to form a set pattern, while technology using DFD (Depth from defocus) cameras is a technique that generates depth information by utilizing multiple images with different focal points captured in the same scene, based on the blurring of focus.

[0006] In addition, a Time of Flight (TOF) camera is a technology that generates depth information by calculating the distance to an object through measuring the time it takes for light emitted from a light source toward the object to reflect off it and return to the sensor. Such TOF cameras have recently been attracting attention due to their advantage of being able to acquire depth information in real time. The problem to be solved

[0007] An embodiment of the invention provides a surface-emitting laser element that selectively provides a dot light source and a flood light source toward an object.

[0008] An embodiment of the invention provides a surface-emitting laser element having at least two emitter groups with different emission angles.

[0009] An embodiment of the invention provides a surface-emitting laser element having a first emitter group in which the emission-side surface is not rough and a second emitter group in which the surface is rough.

[0010] An embodiment of the invention may provide a surface-emitting laser element having a first emitter group and a second emitter group alternately arranged in at least one direction or two or more directions, and a camera module equipped with the same. means of solving the problem

[0011] A surface-emitting laser element according to an embodiment of the invention comprises a first emitting part having a plurality of first emitters arranged therein; and a second emitting part having a plurality of second emitters arranged therein. The first emitting part emits a first beam angle, and the second emitting part emits a second beam angle narrower than the first beam angle. The first emitter and the second emitter may be alternately arranged in at least one direction. The upper surface of the first emitting part is flat, and the upper surface of the second emitting part may include an uneven pattern. The difference between the beam angle of the first emitting part and the beam angle of the second emitting part may be 30 degrees or more. The diameter of the upper surface of the first emitting part and the diameter of the upper surface of the second emitting part may be the same.

[0012] According to an embodiment of the invention, the roughness of the upper surface of the emission side of the first light-emitting part and the second light-emitting part is different from each other, and the first light-emitting part emits a beam angle of 50 degrees or more by first emitters in the entire area, and the second light-emitting part can emit a beam angle of 30 degrees or less by second emitters in the entire area.

[0013] According to an embodiment of the invention, the upper surface of the first light-emitting part may be formed as a rough surface, and the upper surface of the second light-emitting part may be formed as a flat surface.

[0014] According to an embodiment of the invention, the upper surfaces of the first and second light-emitting parts may be formed of a passivation material.

[0015] According to an embodiment of the invention, a plurality of pads electrically connected to the outer side of each of the first and second light-emitting parts may be included.

[0016] According to an embodiment of the invention, the pitch between the first emitters and the pitch between the second emitters may be the same or different from each other.

[0017] A camera module according to an embodiment of the invention may include a light-emitting unit having a surface-emitting laser element and a lens unit on the light-emitting unit; and a light-receiving unit that receives light in the infrared region irradiated by driving the emitters of the light-emitting unit and light scattered or reflected from an object. Effects of the invention

[0018] According to an embodiment of the invention, at least two emitter groups with different beam angles are placed in a single VCSEL to provide dot and flood light sources without a separate VCSEL or driving optical system.

[0019] According to an embodiment of the invention, a dot light source and a flood light source can be configured simultaneously using a fixed-focus optical system, thereby reducing the size of the camera module and making the configuration of the camera module less complex.

[0020] The reliability of a surface-emitting laser element according to an embodiment of the invention and a camera module equipped with the same can be improved.

[0021] The surface-emitting laser element according to an embodiment of the invention can be applied as a distance measuring device in mobile bodies such as vehicles, mobile terminals, cameras, various information measuring devices, robots, computers, medical devices, home appliances, or wearables. Brief explanation of the drawing

[0022] FIG. 1 is a conceptual diagram illustrating a camera module according to an embodiment of the invention. Figure 2 is a drawing showing an example of the light-emitting unit of Figure 1. Figure 3 is an example of a light-emitting part and a lens part in the light-emitting unit of Figure 2. Figure 4 is an example of a plan view showing a plurality of light-emitting parts of the light-emitting part of Figure 1. FIG. 5 is an example of a side cross-sectional view of the first emitter array of FIG. 4. FIG. 6 is an example of a side cross-sectional view showing an array of the first emitter and the second emitter of FIG. 4. Figure 7 is an example of a side cross-sectional view of the second emitter of Figure 6. Figure 8 is another example of an electrode connected to a plurality of light-emitting parts of Figure 4. FIG. 9 is a cross-sectional view of the BB side of the first light-emitting part of FIG. 8. FIG. 10 is a drawing showing an example of the arrangement of emitters and the form of their connection according to an embodiment of the invention. FIG. 11 is a drawing showing an example of a different arrangement of emitters and a connection form thereof according to an embodiment of the invention. Figures 12 (A)-(D) are drawings showing examples of first and second emitters according to embodiments of the invention. FIG. 13 is an example of driving either of the first or second light-emitting parts of FIG. 4. (A) and (B) of FIG. 14 are examples of beam patterns of the first and second light-emitting parts. FIG. 15 is a block diagram of a camera module according to an embodiment of the invention. FIG. 16 is an example of a flowchart of a camera module according to an embodiment of the invention. FIG. 17 is an example of a mobile terminal having a camera module according to an embodiment of the invention. Specific details for implementing the invention

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted. Furthermore, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a meaning generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms used generally, such as those defined in advance, may be interpreted by considering their meaning in the context of the relevant technology. Additionally, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention. In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C. In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are intended merely to distinguish the component from other components and do not determine the essence, order, or sequence of the component. Furthermore, where it is stated that a component is 'connected,' 'combined,' or 'connected' to another component, this may include not only cases where the component is directly connected, combined, or connected to the other component, but also cases where it is 'connected,' 'combined,' or 'connected' due to another component located between the component and the other component.Furthermore, when described as being formed or placed "above or below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0024] <Example>

[0025] FIG. 1 is a conceptual diagram illustrating a camera module according to an embodiment of the invention, FIG. 2 is a diagram showing an example of a light-emitting unit of FIG. 1, FIG. 3 is an example of a lens part in the light-emitting unit of FIG. 2, FIG. 4 is a diagram showing another example of a light-emitting unit of FIG. 1, FIG. 5 is an example of a lens part and a lens driving part in the light-emitting unit of FIG. 4, FIG. 6 is an example of a plan view showing an emitter array of a light-emitting unit in FIG. 2 to FIG. 5, FIG. 7 (a), (b), and (c) are diagrams showing a first region (A1), a second region (A2), and a third region (A3) of FIG. 6, FIG. 8 is a diagram showing a distortion shape of an emitter array of a light-emitting unit of FIG. 6, and FIG. 9 is an example of a side cross-sectional view of an emitter of a surface-emitting laser element of FIG. 6.

[0026] Referring to FIG. 1, the camera module (10) may be a module that irradiates light to detect three-dimensional information, such as distance information, for an object (20) located in front, and acquires the irradiated light in real time. Here, the three-dimensional information may include an image or distance information having three-dimensional depth information using a Time of Flight (ToF) function. For example, the camera module (10) may be applied to a mobile terminal, an unmanned vehicle, an autonomous vehicle, a robot, a drone, a medical device, etc. The camera module (10) may include a LiDAR (Light detection and ranging) device, a sensing device, or an imaging module.

[0027] The camera module (10) may include a light-emitting unit (100) that emits light toward an object (20), a light-receiving unit (200) that receives light reflected from the object (20), and a control unit (300) that controls the light-emitting unit (100) and the light-receiving unit (200). The light-emitting unit (100) may be a unit that generates a light signal and then outputs the generated light signal to the object (20). Such a light-emitting unit (100) may include an emitter array capable of generating light, such as an emitter, and a configuration that outputs light by performing amplitude modulation or phase modulation on the light signal. The light signal may be in the form of a pulse or a continuous wave such as a sinusoid wave, a square wave, or a pulse wave.

[0028] The light signal generated from the light-emitting unit (100) may be output with a distorted path. The light path of the light signal may be projected as a distorted light according to a preset distortion aberration. The light-emitting unit (100) may output light signals of various light patterns, for example, a light signal of a flood lighting pattern or a light signal of a dot lighting pattern. The light-emitting unit (100) may include a structure capable of changing the light path of the light signal according to a control signal from the control unit (300). The light output from the light-emitting unit (100) may be output light or an output signal with respect to the camera module (10). The light output from the light-emitting unit (100) may be incident light or an incident signal with respect to the object (20).

[0029] The light-emitting unit (100) can irradiate the light signal onto the object (20) for a predetermined exposure period (integration time). Here, the exposure period may mean one frame period. For example, if the frame rate of the camera module (10) is 30 FPS (Frames per second), the period of one frame may be 1 / 30 second.

[0031] The light receiving unit (200) may be positioned adjacent to the location of the light emitting unit (100). For example, the light receiving unit (200) may be positioned side by side with the light emitting unit (100). The light receiving unit (200) can detect light reflected from the object (20). Specifically, the light receiving unit (200) can detect light projected from the light emitting unit (100) to the object (20) and reflected through the object (20). The light receiving unit (200) can detect light of a wavelength band corresponding to the light emitted by the light emitting unit (100).

[0032] The light signal reflected from the object (20) can pass through the lens assembly of the light receiving unit (200). The optical axis of the lens assembly can be aligned with the optical axis of the sensor. A filter can be placed between the lens assembly and the sensor. The filter can be placed on the optical path between the object and the sensor. The filter can filter light having a predetermined wavelength range. The filter can transmit a specific wavelength band of light. The filter can transmit light of a specific wavelength. For example, the filter can transmit light in the wavelength band of the light signal output by the light emitting unit (100). The filter can transmit light in the infrared band and block light outside the infrared band. Alternatively, the filter can transmit visible light and block light of wavelengths other than visible light.

[0033] The sensor of the light receiving unit (200) can sense light. The sensor can receive a light signal. The sensor may be an image sensor that senses a light signal. The sensor can detect a light signal and output it as an electrical signal. The sensor can detect light of a wavelength corresponding to the wavelength of light output from a light-emitting element. The sensor can detect light in the infrared band. Alternatively, the sensor can detect light in the visible light band. The sensor may include a pixel array that converts light passing through a lens assembly into a corresponding electrical signal, a driving circuit that drives a plurality of pixels included in the pixel array, and a readout circuit that reads the analog pixel signal of each pixel. The readout circuit can generate a digital pixel signal (or image signal) through analog-to-digital conversion by comparing the analog pixel signal with a reference signal. Here, the digital pixel signal of each pixel included in the pixel array constitutes an image signal, and the image signal can be defined as an image frame as it is transmitted in frame units. That is, the image sensor can output a plurality of image frames.

[0035] The control unit (300) is connected to the light-emitting unit (100) and the light-receiving unit (200) and can control their operation. The control unit (300) can control the operation of the light-emitting unit (100) according to the size, position, shape, etc. of an object (20) located in front of the camera module (10). For example, the control unit (300) can control the intensity of the emitted light, the size of the light pattern, the shape of the light pattern, etc., according to the position of the object (20).

[0036] The camera module (10) may be a Time of Flight (TOF) camera that emits light toward an object (20) and calculates depth information of the object based on the time or phase difference of the light reflected back from the object. Accordingly, the control unit (300) can generate an image based on an electrical signal generated by the light receiving unit (200). The control unit (300) can generate a sub-frame image from an electrical signal generated at each phase pulse period. Additionally, the control unit (300) can generate a single frame image from a plurality of sub-frame images generated during a frame pulse period. Furthermore, the control unit (300) can generate a single high-resolution image through a plurality of sub-frame images or a plurality of frame images. For example, the control unit (300) can generate an image using a Super Resolution (SR) technique.

[0037] Additionally, although not shown in the drawings, the camera module (10) may further include a coupling part (not shown) and a connection part (not shown). The coupling part may be connected to an optical device to be described later. The coupling part may include a circuit board and a terminal disposed on the circuit board. For example, the terminal may be a connector for physical and electrical connection with the optical device. The connection part may be disposed between the substrate of the camera module (10) to be described later and the coupling part. The connection part may connect the substrate and the coupling part. For example, the connection part may include a flexible PCB (FBCB) and may electrically connect the substrate and the circuit board of the coupling part. Here, the substrate may be at least one of the first substrate of the light-emitting unit (100) and the second substrate of the light-receiving unit (200).

[0039] As shown in FIGS. 2 and 3, the light-emitting unit (100) can output a light signal to various irradiation areas. The light-emitting unit (100) includes a light-emitting part (110) having an emitter array, a lens part (120), and a driving part (140), and can output a light signal to various irradiation areas by driving the emitter array to a whole area or individual areas. The light-emitting unit (100) may include an emitter array for changing the irradiation area according to a control signal. The light-emitting part (110) includes an emitter array in which a plurality of emitters are arranged, and the emitters may be partially or entirely driven by the driving part (140), and the lens part (120) includes at least one lens or a plurality of lenses, and can refract light incident from the light-emitting part (110) and focus it toward an object (20).

[0040] The light-emitting unit (110) may include at least one light-emitting element among an edge-emitting laser, a vertical-cavity surface-emitting laser (VCSEL), a distributed feedback laser, an organic light-emitting diode (OLED), or a laser diode (LD). The light-emitting unit (110) will be described, for example, as a surface-emitting laser element.

[0041] The light-emitting unit (110) may include a plurality of emitters. For example, when the plurality of emitters are arranged, each of the plurality of emitters may include a region where light is emitted, such as at least one aperture for light emission. Accordingly, the light-emitting unit (110) may emit light in a set direction.

[0042] The light-emitting unit (110) can emit light of a set wavelength band. Specifically, the light-emitting unit (110) can emit visible light or infrared light. For example, the light-emitting unit (110) can emit visible light of a wavelength band of about 380 nm to about 700 nm. In addition, the light-emitting unit (110) can emit infrared light of a wavelength band of about 700 nm to about 1.1 mm.

[0044] The lens portion (120) may include a laminated structure of one or more solid lenses or / and at least one liquid lens and a housing that accommodates the lens(s). The solid lens may be made of glass or plastic. The lens portion (120) may control the path of the emitted light from the light-emitting portion (110), for example, by diffusing, scattering, refracting, or concentrating the light.

[0045] The lens unit (120) may include a collimator lens. Here, collimating may mean reducing the divergence angle of light, and ideally, it may mean causing light to travel parallel without converging or diverging. That is, the collimator lens can concentrate the light emitted from the light-emitting unit (110) into parallel light. The lens unit (120) can concentrate the light emitted through the plurality of emitters into flood illumination or dot illumination.

[0046] Additionally, the lens unit (120) can improve the uniformity of light emitted from the light-emitting unit (110). Furthermore, the lens unit (120) can prevent the formation of a hot spot where light is concentrated in an area corresponding to the opening of the emitter, for example, where the emitter of the light-emitting unit (110) is positioned. The driving unit (140) can control the driving of the light-emitting unit (110). The driving unit (140) can control the driving of the area or the entire driving of the emitters of the light-emitting unit (110).

[0047] Additionally, the lens unit (120) can prevent light emitted from the light-emitting unit (110) from being directly irradiated onto an object. For example, the lens unit (120) can control the light emitted from the light-emitting unit (110) to prevent light from being directly irradiated onto light-sensitive areas such as human eyes, skin, etc. The lens unit (120) can selectively provide flood lighting and dot lighting without a driving unit such as a separate actuator.

[0048] The distance between the light-emitting unit (110) and the lens unit (120) can be fixed, and without movement along the optical axis, the size of the spot of the light projected from the light-emitting unit (110) to the lens unit (120) can be changed from flood illumination to dot illumination. Here, the lens unit (120) has a fixed focal length, which may be 0.5 mm or more, for example, in the range of 0.5 mm to 15 mm.

[0049] The above-mentioned light-emitting unit (110) is adopted in a camera module, for example, a camera module for 3D image sensing. For example, a camera module for 3D image sensing may be a camera capable of capturing depth information of an object. Meanwhile, for depth sensing of the camera module, a separate sensor is equipped, and it is classified into two types: Structured Light (SL) method and Time of Flight (ToF) method. In the Structured Light (SL) method, a laser of a specific pattern is emitted onto a subject, and then depth is calculated based on the degree to which the pattern is deformed according to the shape of the subject's surface, and then combined with a photo taken by an image sensor to obtain a 3D image capture result. In contrast, the ToF method measures the time it takes for a laser to reflect back from a subject to calculate depth, and then combines with a photo taken by an image sensor to obtain a 3D capture result. Accordingly, the SL method requires the laser to be positioned very accurately, whereas ToF technology has the advantage of being suitable for mass production as it relies on an improved image sensor, and either one or both methods can be adopted in a single mobile phone.

[0050] The above ToF has direct / indirect types. The indirect type measures distance using the phase difference between the emitted light and the received light, and can be driven to repeatedly turn on and off at a predetermined period by modulating the light source of a surface-emitting laser element (VCSEL). Here, the pixels of the sensor may include pixels that turn on and off at the same period as the light source and pixels that turn on and off with a phase difference of 180 degrees. In the indirect type, distance is measured by detecting the phase difference, and the same distance can be recognized when the phase difference is 0 and when it is 360 degrees. For example, a first case where an object is located directly in front of the light source and a second case where the object is far from the light source and the time it takes for the light to return is equal to the period in which the phase changes by 360 degrees can be processed and recognized as the same distance. In the first case above, the light emitted by the light source can be detected by the sensor immediately without a phase difference, and in the second case, the phase difference between the light source and the reflected light received by the sensor becomes 360 degrees, and the phase difference disappears again. Accordingly, the blinking cycle of the light source and the sensor must be matched according to the target distance, and in particular, as the distance between objects increases, the blinking cycle can be set to be longer (modulation frequency reduced).

[0052] As shown in FIGS. 4 to 7, the light-emitting unit (110) may include a surface-emitting laser element in which a plurality of emitters (201, 202) are arranged. The surface-emitting laser element may include a plurality of light-emitting units (E1, E2) that emit light selectively according to an illumination mode. For example, the surface-emitting laser element (200) may include a first light-emitting unit (E1) that emits light in a first region and a second light-emitting unit (E2) that emits light in a second region. The first and second regions may be the entire region. The surface-emitting laser element may include a first light-emitting unit (E1) and / or a second light-emitting unit (E2) that irradiate light having different field of view (FOV). The surface-emitting laser element may include a first light-emitting unit (E1) and / or a second light-emitting unit (E2) that irradiate light for different zoom functions.

[0053] The above surface-emitting laser element may include a first light-emitting part (E1), a first pad (101) connected to the first emitters (201) of the first light-emitting part (E1), a second light-emitting part (E2), and a second pad (102) connected to the second emitters (202) of the second light-emitting part (E2). The first light-emitting part (E1) includes an array of the first emitters (201), and the array of the first emitters (201) may be arranged in a matrix form in a first region. The first region is the entire area of ​​the surface-emitting laser element, and the horizontal length may be equal to or greater than the vertical length. The ratio of the horizontal length to the vertical length may be 4:3 or a:b, where a > b, and a may be greater than 1 time than b.

[0054] A light-emitting unit (110) having a surface light-emitting element according to an embodiment of the invention may include at least two types of emitters with different beam angles, and the at least two types of emitters may be alternately arranged in at least one or two directions among the first and second directions (X, Y). The at least two types of emitters may be alternately arranged in at least one or more directions among at least three directions (X, Y, Z in FIG. 12).

[0055] The first light-emitting unit (E1) is focused with a first beam angle wider than the second light-emitting unit (E2) and can emit flood light. As shown in (B) of FIG. 14, the first beam angle of the first light-emitting unit (E1) may be 50 degrees or more, for example, in the range of 50 degrees to 120 degrees. As shown in (B) of FIG. 14 and FIG. 13, when the second light-emitting unit (E2) emits light, it is focused with a second beam angle narrower than the first light-emitting unit (E1) and can emit dot light. The second beam angle of the second light-emitting unit (E2) may be 30 degrees or less, for example, in the range of 5 degrees to 30 degrees or in the range of 15 degrees to 30 degrees. Here, when measured at a distance of 10 cm from the detector on the surface-emitting laser element, the dot size of the narrow angle may be 1.5 mm or less, and the dot size of the wide angle may be 2 mm or more. The second beam angle may be in the range of 1 / 6 to 5 / 6 or 1 / 4 to 3 / 4 of the first beam angle. The first beam angle may be provided as flood illumination, and the second beam angle may be provided as dot illumination. The beam angle (1 / e) of the first light-emitting part (E1) 2 ) is provided as a wide angle, and the beam angle (1 / e) of the second light-emitting part (E2) is provided as a wide angle. 2 ) can be provided as a narrow angle.

[0056] The array of the first emitter (201) and the second emitter (202) may be arranged as the same emitter array in at least one direction among several directions, e.g., the second direction (Y), and may not be arranged alternately with other emitter arrays. The first emitter (201) and the second emitter (202) may have electrodes (101, 102) arranged in the array direction, so that connection with the electrodes (101, 102) may be easy. The surface roughness of the upper surface of the emission side of the first light-emitting part (E1) and the second light-emitting part (E2) may be different from each other.

[0057] The first emitter (201) and the second emitter (202) may have the same number of emitters or the first emitter (201) may be more numerous, but are not limited thereto. The first emitter (201) and the second emitter (202) may be arranged alternately in at least one direction, or alternately arranged in at least two rows and / or two columns, or each of the second emitters (202) may be arranged between the first emitters (201).

[0058] The first emitter (201) may be distributed uniformly across the entire area for uniformity of flood lighting. The second emitters (202) may be placed in a pentagonal area connecting the first emitter (201) or within seven emitters, with at least one being placed, for example, in a range of one to three.

[0059] The pitch between the first emitters (201) in the first direction (Y) may be the same as each other, and the pitch between the second emitters (202) may be the same as each other. The pitch between the first emitters (201) and the second emitters (202) in the first direction (Y) may be the same as each other. The pitch between the first emitters (201) in the first direction (Y) may be twice the pitch between adjacent first and second emitters (201, 202). The pitch between the first emitters (201) or the pitch between the second emitters (202) in the second direction (X) may be the same as each other. The pitch may be, for example, 20 μm or more, for example, 40 to 60 μm or 20 to 50 micrometers, considering the light-emitting layer.

[0060] The area ratio between the second emitter (202) and the first emitter (201) may be in the range of 4:6 to 6:4. Here, the total number of the first emitters (201) may be 450 or more, for example, in the range of 450 to 600, and the number of the second emitters (202) may be at least 400 or more, for example, in the range of 400 to 550. Accordingly, dot lighting can be provided by driving the first light-emitting unit (E1), and flood lighting can be provided by driving the second light-emitting unit (E2). The first and second light-emitting units (E1, E2) may be driven alternately or simultaneously.

[0061] The first and second emitters (201, 202) may include, for example, a vertical-cavity surface emitting laser (VCSEL). Each of the first and second emitters (201, 202) may be defined as an emitter having an aperture. The first and second emitters (201, 202) may emit light in a range of 750 nm or longer, for example, from 750 nm to 1100 nm or from 750 nm to 950 nm. The first and second emitters (201, 202) may emit the same peak wavelength.

[0062] As shown in FIG. 5, the first emitters (201) can emit light when power is supplied to the first pad (101). The first pad (101) can be electrically connected to a first electrode (280) extended through the upper part of the first light-emitting part (E1). As shown in FIG. 6, the second emitters (202) can emit light when power is supplied to the second pad (102). The second emitters (202) can be electrically connected to a second electrode (290) extended through the upper part of the second light-emitting part (E2). The first pad (101) may be an area of ​​the outer region of the first electrode (280) to which an external power terminal, such as a wire or a bonding member, is connected. The second pad (102) may be an area of ​​the outer region of the second electrode (290) to which an external power terminal, such as a wire or a bonding member, is connected.

[0064] As shown in FIG. 9, at least one of the electrodes may overlap, for example, the second electrode (290) of the second pad (102) and the second emitter (202) may be connected by a bridge electrode (295). The bridge electrode (295) may be arranged in one or multiple numbers. The bridge electrode (295) may extend along the outer upper portion of the first light-emitting portion (E1). The width of the bridge electrode (295) may be equal to or smaller than the width of the second pad (102). The width of the bridge electrode (295) may be equal to or smaller than the horizontal width of the second light-emitting portion (E2). An embodiment of the invention can reduce light loss by arranging the bridge electrode (295) of the second electrode (290) to overlap vertically with the first connection portion (284) of the first electrode (280). In addition, the area where the second pad (102) is formed is formed separately from the first pad (101), thereby having the effect of being formed as a single layer. Therefore, by selectively stacking the first and second electrodes (280, 290) in a multilayer manner at the boundary area of ​​the emitters, metal (e.g., Au) material can be reduced, and by forming the width of the bridge electrode of the second electrode (290) as wide as possible, the operating voltage can be reduced and current diffusion can be improved.

[0065] In addition, when driving the entire area of ​​the surface-emitting laser element, by driving each using the first emitter (201) and / or the second emitter (202), flood lighting and dot lighting can be provided without a driving part such as an actuator.

[0066] The first emitter (201) may have a flat or flat upper surface (272), and the second emitter (202) may have a rough upper surface (274). The rough surface (274) may be formed with an irregular uneven pattern. Light emitted through the second emitter (202) having such a rough surface (274) may be scattered or diffused because the angle of refraction of the light is greater than that of the flat upper surface (272), and thus may be provided as flood lighting. Conversely, the first emitter (201) having a flat upper surface (272) may emit light as dot lighting. As shown in FIG. 7, the width (D2) of the rough surface (272) of the second emitter (202) may be larger than the width (D1) of the opening (241) of the oxide layer (240) and smaller than the width (D3) of the window area (255) turned off by the second electrode (290). The thickness of the passivation (270) forming the rough surface (272) is in the range of 3 / (4n)×λ, where n is the refractive index of the passivation layer (270) and λ is the incident wavelength. The rough surface (272) may be etched to less than 50% of the thickness of the passivation layer (270).

[0067] Here, the structure of the first and second emitters (201, 202) is described with the first emitter (201) as the central focus, and the second emitter (202) is described by referring to the description of the first emitter (201). Furthermore, regarding the structure of the second emitter (202), configurations different from the first emitter (201) and additional configurations, they will be described later.

[0068] Referring to FIGS. 5 to 7, the first emitter (201) may include a lower electrode (215), a substrate (210), a first reflective layer (220), a light-emitting layer (230), an oxide layer (240), a second reflective layer (250), a passivation layer (270), and a first electrode (280). The first electrode (280) may include a first contact portion (282) and a first connection portion (284). The second electrode (290) may include a second contact portion (292) and a second connection portion (294), and the description of the first electrode (280) will be referenced.

[0069] The first emitter (201) may include a substrate (210). The substrate (210) may be a conductive substrate or a non-conductive substrate. The conductive substrate may be a metal with excellent electrical conductivity. Since the substrate (210) must be able to sufficiently dissipate the heat generated during the operation of the first emitter (201), it may include a GaAs substrate or a metal substrate with high thermal conductivity, or a silicon (Si) substrate. The non-conductive substrate may be an AlN substrate, a sapphire (Al2O3) substrate, or a ceramic-based substrate.

[0070] The lower electrode (215) may be disposed on the lower part of the substrate (210). The lower electrode (215) may be disposed in a single layer or a multilayer structure using a conductive material. For example, the lower electrode (215) may be a metal and may be formed in a single layer or a multilayer structure including at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au) to improve electrical characteristics and increase light output. The lower electrode (215) may be a common electrode or a cathode terminal that is commonly connected to the first emitter (201) and the second emitter (202).

[0071] The first reflective layer (220) may be disposed on a substrate (210). If the substrate (210) is omitted to reduce thickness, the lower surface of the first reflective layer (220) may be in contact with the upper surface of the lower electrode (215). The first reflective layer (220) may be doped with a first conductive type dopant. For example, the first conductive type dopant may include n-type dopants such as Si, Ge, Sn, Se, Te, etc. The first reflective layer (220) may include a gallium-based compound, for example, AlGaAs, but is not limited thereto. The first reflective layer (220) may be a Distributed Bragg Reflector (DBR). For example, the first reflective layer (220) may have a structure in which a first layer and a second layer containing materials having different refractive indices are alternately stacked at least once. The thickness of the layer in the first reflective layer (220) can be determined according to the respective refractive index and the wavelength of light emitted from the light-emitting layer (230).

[0072] The light-emitting layer (230) may be disposed on the first reflective layer (220). Specifically, the light-emitting layer (230) may be disposed between the first reflective layer (220) and the second reflective layer (250). The light-emitting layer (230) may include an active layer and at least one cavity inside, and the active layer may include any one of a single well structure, a multi-well structure, a single quantum well structure, a multi-quantum well (MQW) structure, a quantum dot structure, or a quantum wire structure. The active layer may be formed in a 1 to 3 pair structure using a group 3-5 or group 2-6 compound semiconductor material, having pairs such as InGaAs / AlxGaAs, AlGaInP / GaInP, AlGaAs / AlGaAs, AlGaAs / GaAs, GaAs / InGaAs, etc., but is not limited thereto. The cavity is Al y Ga (1-y)As(0 <y<1) 물질로 형성될 수 있으며, Al y Ga (1-y) It may include multiple layers made of As, but is not limited thereto.

[0073] The oxide layer (240) may include an insulating region (242) and an opening (241). The insulating region (242) may surround the opening (241). For example, the opening (241) may be placed on the light-emitting region (center region) of the light-emitting layer (230), and the insulating region (242) may be placed on the non-light-emitting region (edge ​​region) of the light-emitting layer (230). The non-light-emitting region may surround the light-emitting region. The opening (241) may be a passage region through which current flows. The insulating region (242) may be a blocking region that blocks the flow of current. The insulating region (242) may be referred to as an oxide layer or an oxide layer. Since the oxide layer (240) limits the flow or density of current to allow a more concentrated laser beam to be emitted, it may be referred to as a current confinement layer.

[0074] The amount of current supplied from the first electrode (280) to the light-emitting layer (230), i.e., the current density, can be determined by the size of the opening (241). The size of the opening (241) can be determined by the insulating region (242). As the size of the insulating region (242) increases, the size of the opening (241) decreases, and accordingly, the current density supplied to the light-emitting layer (230) can increase. In addition, the opening (241) may be a passage through which a beam generated in the light-emitting layer (230) proceeds in an upward direction, i.e., in the direction of the second reflective layer (250). That is, depending on the size of the opening (241), the divergence angle of the beam of the light-emitting layer (230) may vary.

[0075] The insulating region (242) may be made of an insulating layer, for example, aluminum oxide (Al2O3). For example, if the oxide layer (240) contains AlGaAs (aluminum gallium arsenide), the AlGaAs of the oxide layer (240) reacts with H2O to change the edges into aluminum oxide (Al2O3) to form the insulating region (242), and the central region that does not react with H2O may become an opening (241) containing AlGaAs.

[0076] Light emitted from the light-emitting layer (230) can be emitted to an upper region through the opening (241), and the light transmittance of the opening (241) may be higher than that of the insulating region (242). The insulating region (242) may include a plurality of layers, for example, at least one layer may include a group 3-5 or group 2-6 compound semiconductor material.

[0077] The second reflective layer (250) may be disposed on the oxide layer (240). The second reflective layer (250) may include a gallium-based compound, for example, AlGaAs. The second reflective layer (250) may be doped with a second conductivity type dopant. The second conductivity type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, Ba, etc. As another example, the first reflective layer (220) may be doped with a p-type dopant, and the second reflective layer (250) may be doped with an n-type dopant. The second reflective layer (250) may be a Distributed Bragg Reflector (DBR). For example, the second reflective layer (250) may have a structure in which a plurality of layers containing materials having different refractive indices are alternately stacked at least once. Each layer of the second reflective layer (250) may include AlGaAs, and in detail, Al with a different composition of x x Ga (1-x)As(0 <x<1)의 조성식을 갖는 반도체 물질로 이루어질 수 있다. 여기서, Al이 증가하면 각 층의 굴절률은 감소하고, Ga가 증가하면 각 층의 굴절률은 증가할 수 있다. 상기 제2 반사층(250)의 각 층의 두께는 / 4n and, θ may be the wavelength of light emitted from the active layer, and n may be the refractive index of each layer for light of the aforementioned wavelength.

[0078] The second reflective layer (250) may be formed by alternately stacking layers, and the number of pairs of layers within the first reflective layer (220) may be greater than the number of pairs of layers within the second reflective layer (250). Here, the reflectance of the first reflective layer (220) may be greater than the reflectance of the second reflective layer (250).

[0079] Here, the layers from the first reflective layer (220) to the second reflective layer (250) can be defined as a light-emitting structure. The upper part of the light-emitting structure may be provided with an outer side that is inclined. The upper part of the light-emitting structure may be exposed as an inclined side by a mesa etching process.

[0080] A passivation layer (270) may be disposed around the upper perimeter of a light-emitting structure. The upper part of the light-emitting structure may include, for example, a light-emitting layer (230), an oxide layer (240), and a second reflective layer (250). The passivation layer (270) may be disposed on the upper surface of the first reflective layer (220). The passivation layer (270) may be disposed on the edge region of the second reflective layer (250). When the light-emitting structure is partially mesa-etched, a portion of the upper surface of the first reflective layer (220) may be exposed, and a portion of the light-emitting structure may be disposed in a protruding form. The passivation layer (270) may be disposed around the perimeter of a portion of the light-emitting structure and on the upper surface of the exposed first reflective layer (220).

[0081] The passivation layer (270) can protect the light-emitting structure from the outside and block electrical short circuits between the first reflective layer (220) and the second reflective layer (250). The passivation layer (270) can be formed of an insulating material or a dielectric material, and can be formed of an inorganic material such as SiO2, but is not limited thereto.

[0082] The passivation layer (270) may provide a flat upper surface (272) and a rough surface (274) on the second reflective layer (250) on the first and second light-emitting parts (E1, E2). The rough surface (274) may be formed into an irregular uneven pattern by wet etching.

[0083] The first electrode (280) may include a first contact portion (282) and a first connecting portion (284) connected to the first contact portion (282). The first contact portion (282) may be in contact with a portion of the upper surface of the second reflective layer (250). The first contact portion (282) may be in ohmic contact with the second reflective layer (250). The first connecting portion (284) may connect the first contact portion (282) with the first pad (101 in FIG. 4) and may connect adjacent first emitters (201).

[0084] The first contact portion (282) and the first connection portion (284) may be made of a conductive material. For example, the first contact portion (282) and the first connection portion (284) may be formed in a single-layer or multi-layer structure including at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). The first contact portion (282) and the first connection portion (284) may be made of the same metal or non-metal material, or may be formed of different materials. The second contact portion (292) and the second connection portion (294) may be selected from the materials of the first contact portion (282) and the first connection portion (284).

[0085] The first contact portion (282) may be in contact with the second reflective layer (250) at the outer perimeter of the passivation layer (270) which overlaps vertically with the opening (241). The first contact portion (282) may be in contact with the second reflective layer (250) through the passivation layer (270) and may be arranged in a loop shape or a closed loop shape at the upper perimeter of the second reflective layer (250).

[0086] As shown in FIG. 4, when viewed from a top view, each of the first and second emitters (201, 202) may have the opening (241) positioned in the center and the insulating area (242) and the first and second contact parts (282, 292) positioned around the opening (241). A flat upper surface (272) and a rough surface (274) may be exposed above the opening (241), overlapping vertically with the opening (241).

[0088] As shown in FIGS. 8 and 9, the second insulating layer (287) may be further disposed in the boundary region between the first light-emitting part (E1) and the second light-emitting part (E2). The second insulating layer (287) may insulate the first connecting part (284) of the first electrode (280) of the first light-emitting part (E1) and the second connecting part (294) of the second electrode (290) of the second light-emitting part (E2). Accordingly, the second insulating layer (287) may electrically and physically separate the second connecting part (294) of the second electrode (290) of the second light-emitting part (E2) from the first electrode (280) of the first light-emitting part (E1) from the outside. The second insulating layer (287) may be extended in a straight line in one direction along the boundary region or extended in a zigzag shape. That is, the second insulating layer (287) may be placed in an area that does not spatially affect adjacent emitters (201, 202) or extend between the first connecting portion (284) of the first electrode (280) and the second connecting portion (294) of the second electrode (290) or the bridge electrode (295) so as not to affect the opening (241).

[0089] The first insulating layer (285) and the second insulating layer (287) may be made of an insulating material, for example, a nitride or an oxide, and may include at least one of polyimide, silica (SiO2), or silicon nitride (Si3N4).

[0091] As shown in FIGS. 10 and 11, the light-emitting portions (E1, E2) of the emitter array may be arranged in the form of multiple lines, or pads (101, 102) that supply power to the multiple lines may be connected to each of them. Dot illumination or flood illumination may be implemented according to the line-by-line driving of each emitter. For example, pads may be selectively connected to the emitters of alternating horizontal lines or / and vertical lines to control the light-emitting active area. While controlling the lines or / and active area of ​​these light-emitting emitters, distortion may be applied through the lens portion.

[0093] As shown in (A) of FIG. 12, the first and second light-emitting units (E1, E2) may be arranged in a 2:1 ratio between the first light-emitting unit (E1) and the second light-emitting unit (E2) along a column in the third direction (W), and may be arranged in a 2:1 ratio between the first light-emitting unit (E1) and the second light-emitting unit (E2) along a column in the second direction (Y). The first light-emitting unit (E1) and the second light-emitting unit (E2) may be arranged alternately and in a zigzag pattern in the first direction (X).

[0094] As shown in (B) of FIG. 12, the first and second light-emitting units (E1, E2) may be arranged in a 3:1 ratio along a column in the third direction (W), and the first light-emitting unit (E1) and the second light-emitting unit (E2) may be arranged in a 1:1 ratio along one of two columns in the second direction (X). The first light-emitting unit (E1) and the second light-emitting unit (E2) may be arranged in an alternating and zigzag pattern in the first direction (X).

[0095] As shown in (C) of FIG. 12, the first and second light-emitting units (E1, E2) may be arranged alternately along the fourth direction (V) and the first and second light-emitting units (E1, E2) may be arranged in a 1:1 ratio along the second and third directions (Y, W). The first light-emitting unit (E1) and the second light-emitting unit (E2) may be arranged alternately in the first direction (X).

[0096] As shown in (D) of FIG. 12, the first and second light-emitting units (E1, E2) are alternately arranged in the first direction (Y), and for the second direction (X) and the third direction (W), the second light-emitting unit (E2) may be alternately arranged in one of the two rows of the first light-emitting unit (E1).

[0098] As shown in FIG. 15, the camera module may include a light-emitting unit (100), a light-receiving unit (420), a plurality of amplifiers (470), a peak detector (472), a selection unit (474), and a processor (476). The light-emitting unit (100) may irradiate light toward an object through the first and second light-emitting units (112, 114) disclosed above. The light-emitting unit (100) may include a driving unit (140) having a first driving unit (142) that drives the first light-emitting unit (112) and a second driving unit (144) that drives the second light-emitting unit (114). The first and second driving units (142, 144) may be implemented as driver ICs.

[0099] The light receiver (420) can detect light reflected or scattered from the object (20) and output an electrical signal. The light receiver (420) can detect scattered light and output an electrical signal. The light receiver (420) can convert the reflected or scattered light into a voltage signal. A plurality of amplifiers (470) can amplify the electrical signal with different gains to generate a plurality of amplified electrical signals. The plurality of amplifiers (470) can have different gain values ​​ranging from a low gain value to a high gain value.

[0100] A plurality of peak detectors (472) can detect a peak for each of the amplified signals and generate a peak detection signal, and each peak detector (472) can detect a peak by detecting the center position of the amplified electrical signal.

[0101] The selection unit (474) can select an optimal peak detection signal based on the level of at least one amplified electrical signal among a plurality of amplified electrical signals.

[0102] The processor (476) can control the operation of each component of the distance measuring device. The distance measuring device may include a memory in which the operation performed by the processor (476) is stored with programs and other data. The processor (476) may include a Time to Digital Converter (TDC) that measures the time between the time of irradiation of light irradiated from the first and / or second light-emitting parts (112, 114) of the light-emitting part (100) and the time of detection of a peak detected by the peak detector (474), and the processor (476) may measure the distance to the object (20) based on the time measured by the TDC. According to another embodiment, the processor (476) may include an Analog-to-Digital Converter (ADC) that converts the peak, which is an analog signal, into a digital signal, and the processor (476) may measure the distance to the object (20) by processing the digital signal converted by the ADC. Using this signal, flood lighting and spot lighting can be detected.

[0104] As shown in FIG. 16, the surface-emitting laser element may select either or both of the first and second light-emitting units (S21), and the selected light-emitting unit is driven by the first and second driving units (S22), and infrared light may be irradiated toward an object. Subsequently, the light receiver receives the light irradiated by the first and / or second light-emitting units (S24), and can detect a three-dimensional image or distance by analyzing the received light. At this time, flood lighting may be irradiated when the second light-emitting unit is driven, and spot lighting may be irradiated when the first light-emitting unit is driven. Accordingly, a three-dimensional image or distance corresponding to an object can be measured by the light received by the light receiver.

[0106] FIG. 17 is a perspective view showing an example of a mobile terminal to which a surface-emitting laser element according to an embodiment of the invention is applied.

[0107] As illustrated in FIG. 17, the mobile terminal (1500) may include a camera module (1520), a flash module (1530), and an autofocus device (1510) provided on one side or the rear side. Here, the autofocus device (1510) may include a surface-emitting laser element and a light receiver disclosed above as a light-emitting layer.

[0108] The flash module (1530) may include an emitter that emits light inside. The flash module (1530) may be operated by the camera operation of a mobile terminal or by user control. The camera module (1520) may include an image capturing function and an autofocus function. For example, the camera module (1520) may include an autofocus function using an image.

[0109] The above autofocus device (1510) may include an autofocus function using a laser. The above autofocus device (1510) may be mainly used in conditions where the autofocus function using the image of the camera module (1520) is degraded, such as in a close distance of 10m or less or in a dark environment.

[0110] The foregoing detailed description should not be interpreted restrictively in all respects and should be considered exemplary. The scope of the embodiments should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the embodiments are included within the scope of the embodiments.

Claims

Claim 1 A surface-emitting laser element comprising: a first light-emitting portion having a plurality of first emitters arranged therein; and a second light-emitting portion having a plurality of second emitters arranged therein, wherein the upper surface of the first light-emitting portion is flat, the upper surface of the second light-emitting portion has an uneven pattern, and the first emitters and the second emitters are alternately arranged in at least one direction. Claim 2 A surface-emitting laser element according to claim 1, wherein the first light-emitting part emits a first beam angle and the second light-emitting part emits a second beam angle narrower than the first beam angle. Claim 3 A surface-emitting laser element according to claim 1, wherein the difference between the beam angle of the first emitting part and the beam angle of the second emitting part is 30 degrees or more. Claim 4 In claim 1, the upper surface of the first and second light-emitting parts is formed of a passivation material, the surface-emitting laser element. Claim 5 A surface-emitting laser element according to claim 1, comprising a plurality of pads electrically connected to the outer side of each of the first and second light-emitting parts. Claim 6 A surface-emitting laser element according to claim 1, wherein the diameter of the upper surface of the first light-emitting part and the diameter of the upper surface of the second light-emitting part are the same. Claim 7 A camera module comprising: a light-emitting unit having a surface-emitting laser element of claim 1 and a lens unit having a lens unit on the light-emitting unit; and a light-receiving unit that receives light in the infrared region irradiated by driving the emitters of the light-emitting unit and light scattered or reflected from an object.

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