Camera device

Abstract

The camera device according to an embodiment of the present invention includes a light emitting unit that irradiates an object with an optical signal, a light receiving unit that includes an image sensor and receives the optical signal reflected from the object, and a depth information generation unit that generates depth information of the object using the optical signal received by the light receiving unit. The light emitting unit includes a light source and a microlens array disposed on the light source. The microlens array includes a first region including a plurality of first microlenses having a first diameter, a second region surrounding the first region and including a plurality of second microlenses having a second diameter, and a third region surrounding the second region and including a plurality of third microlenses having a third diameter. The number and diameter of the microlenses included in at least one of the first to third regions have a correlation with the diameter of the microlenses included in another region surrounding at least one of the first to third regions.

Description

Technical Field

[0001] The present invention relates to a camera device.

Background Art

[0002] 3D content is applied in many fields such as games, culture, education, manufacturing, and autonomous driving. To obtain 3D content, depth information (Depth Map) is required. Depth information is information indicating the distance in space and shows the perspective information of other points with respect to a point in a 2D video. As a method for obtaining depth information, a method of projecting IR (Infrared) structured light onto an object, a method using a stereo camera, a TOF (Time of Flight) method, etc. are used.

[0003] According to the TOF method, the distance to an object is calculated by measuring the flight time, that is, the time it takes for light to be emitted and reflected back. The greatest advantage of the TOF method is that it can quickly provide distance information for a 3D space in real time. Also, accurate distance information can be obtained without the user applying a separate algorithm or performing hardware correction. Moreover, accurate depth information can be obtained even when measuring a very close subject or a moving subject.

[0004] On the other hand, in order to obtain depth information, the light emitting unit of the camera device generates an output optical signal and irradiates the object, the light receiving unit of the camera device receives the input optical signal reflected from the object, and the depth information generation unit of the camera device generates the depth information of the object using the input optical signal received by the light receiving unit.

[0005] Generally, in order to obtain depth information, the light emitting unit of the camera device can convert an IR laser beam into a surface illumination pattern having a predetermined FoI (Field of Illumination) and irradiate the object. In order to convert the IR laser beam into a surface illumination pattern, the light emitting unit of the camera device can include a diffusing member, and an example of the diffusing member is a micro lens array (MLA).

[0006] The uniformity of the surface illumination pattern may change depending on the design of the micro lens array, and the safety level for the user's eyes may change. Thus, the design of the micro lens array is important.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The technical problem that the present invention aims to solve is to provide a camera device capable of extracting depth information with high precision and resolution.

[0008] The technical problem that the present invention aims to solve is to provide a camera device including a light emitting unit having a high uniformity of the surface illumination pattern and excellent safety for the user's eyes.

Means for Solving the Problems

[0009] A camera device according to an embodiment of the present invention includes a light emitting unit that irradiates an object with an optical signal, a light receiving unit that includes an image sensor and receives the optical signal reflected from the object, and a depth information generation unit that generates depth information of the object using the optical signal received by the light receiving unit. The light emitting unit includes a light source and a microlens array disposed on the light source. The microlens array includes a first region including a plurality of first microlenses having a first diameter, a second region surrounding the first region and including a plurality of second microlenses having a second diameter, and a third region surrounding the second region and including a plurality of third microlenses having a third diameter. The number and diameter of the microlenses included in at least one of the first to third regions have a correlation with the diameter of the microlenses included in another region surrounding at least one of the first to third regions.

[0010] The first diameter, the second diameter, and the third diameter may be different from each other.

[0011] The first region includes x1 first microlenses arranged along a first direction, the second region includes x2 second microlenses arranged along the first direction, and the third region includes x3 third microlenses arranged along the first direction. The product of the first diameter and x1 may be the same as the product of the second diameter and a number one less than x1, and the product of the second diameter and x2 may be the same as the product of the third diameter and a number one less than x2.

[0012] In the first region, x1 first microlenses may be arranged along a second direction perpendicular to the first direction, in the second region, x2 second microlenses may be arranged along the second direction, and in the third region, x3 third microlenses may be arranged along the second direction.

[0013] The plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses protrude in a direction toward the light source, and the protrusion heights of the plurality of first microlenses, the protrusion heights of the plurality of second microlenses, and the protrusion height of the third microlenses may be different from each other.

[0014] Each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses may have an aspherical shape.

[0015] The aspherical shape of each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses can be defined by an image height, a radius of curvature, and a conic constant.

[0016] The aspherical shape of each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses can be defined by the following mathematical formula:

[0017] JPEG2025521591000002.jpg2371

[0018] Here, x is the X-axis image height, y is the Y-axis image height, R x is the X-axis radius of curvature, R y is the Y-axis radius of curvature, K x is the x-axis conic constant, K y is the Y-axis conic constant.

[0019] The number and diameter of the first microlenses included in the first region can have a correlation with the diameter of the second microlenses included in the second region.

[0020] The distance from the center of the microlens array to the second microlens may be greater than the distance from the center of the microlens array to the first microlens.

[0021] The first diameter, the second diameter, and the third diameter can vary depending on the distance between the light source and the microlens array.

[0022] A camera device according to another embodiment of the present invention includes a light emitting unit that irradiates an object with an optical signal, a light receiving unit that includes an image sensor and receives the optical signal reflected from the object, and a depth information generation unit that generates depth information of the object using the optical signal received by the light receiving unit. The light emitting unit includes a light source and a microlens array disposed on the light source. The microlens array includes a first region including a plurality of first microlenses having a first average diameter, and a second region surrounding the first region and including a plurality of second microlenses having a second average diameter different from the first average diameter. The diameters of the plurality of first microlenses are different from each other, and the diameters of the plurality of second microlenses are different from each other.

[0023] The diameters of the plurality of first microlenses may be included in a range of 0.95 to 1.05 times the first average diameter, and the diameters of the plurality of second microlenses may be included in a range of 0.95 to 1.05 times the second average diameter.

[0024] The second average diameter may be larger than the first average diameter.

[0025] The second average diameter may be 1.1 times or more the first average diameter.

[0026] The diameters of the plurality of first microlenses and the diameters of the plurality of second microlenses can be designed by random number generation, respectively.

[0027] The diameters of the plurality of first microlenses are designed by random number generation using a Gaussian function distribution based on the first average diameter and a first standard deviation, and the diameters of the plurality of second microlenses can be designed by random number generation using a Gaussian function distribution based on the second average diameter and a second standard deviation different from the first standard deviation.

[0028] The diameters of the plurality of first microlenses and the diameters of the plurality of second microlenses can be extracted by rejection sampling for each of the number of the plurality of first microlenses and the number of the plurality of second microlenses, respectively.

[0029] Further including a third region surrounding the second region and including a plurality of third microlenses having a third average diameter different from the first average diameter and the second average diameter, the number and average diameter of the microlenses included in at least one of the first to third regions can have a correlation with the average diameter of the microlenses included in another region surrounding at least one of the first to third regions.

[0030] The first region includes x1 first microlenses arranged along a first direction, the second region includes x2 second microlenses arranged along the first direction, the third region includes x3 third microlenses arranged along the first direction, and the product of the first average diameter and x1 may be the same as the product of the second average diameter and a number one less than x1, and the product of the second average diameter and x2 may be the same as the product of the third average diameter and a number one less than x2.

[0031] In the first region, x1 first microlenses are arranged along a second direction perpendicular to the first direction, in the second region, x2 second microlenses are arranged along the second direction, and in the third region, x3 third microlenses may be arranged along the second direction.

[0032] The first average diameter and the second average diameter may be average diameters in a first direction perpendicular to the optical axis direction, the optical axis direction, a second direction perpendicular to the first direction, or the optical axis direction, respectively.

[0033] An optical output device according to an embodiment of the present invention includes a light source and a microlens array disposed on the light source. The microlens array includes a first region including a plurality of first microlenses having a first average diameter, and a second region surrounding the first region and including a plurality of second microlenses having a second average diameter different from the first average diameter. Diameters of the plurality of first microlenses are different from each other, and diameters of the plurality of second microlenses are different from each other.

[0034] A camera device according to another embodiment of the present invention includes a light emitting unit that irradiates an object with a first optical signal, a light receiving unit that receives a second optical signal reflected from the object, and a depth information generation unit that generates depth information of the object using the second optical signal. The light emitting unit includes a light source and a microlens array disposed on the light source. The microlens array includes a plurality of microlenses arranged in at least a 3×3 matrix, and the plurality of microlenses arranged in the 3×3 matrix have different FoIs (Fields of Illumination) from each other.

[0035] 50% or more of the microlens array may be microlenses having different FoIs from each other.

[0036] At least one of an aspherical shape, a radius of curvature, and a conic constant of the plurality of microlenses arranged in the 3×3 matrix may be different from each other.

[0037] The plurality of microlenses arranged in the 3×3 matrix are arranged in a first region including the center of the microlens array. The microlens array further includes a plurality of microlenses arranged in a second region surrounding the first region. At least one of an aspherical shape, a radius of curvature, and a conic constant of the plurality of microlenses arranged in the first region may be different from each other.

[0038] At least one of the aspherical shape, radius of curvature, and conic constant of the plurality of microlenses disposed in the second region may be different from each other.

[0039] The plurality of microlenses disposed in the first region have a first average diameter, the plurality of microlenses disposed in the second region have a second average diameter different from the first average diameter, the plurality of microlenses disposed in the first region have different diameters from each other, and the plurality of microlenses disposed in the second region can have different diameters from each other.

[0040] A camera device according to another embodiment of the present invention includes a light emitting unit that irradiates an object with a first optical signal, a light receiving unit that receives a second optical signal reflected from the object, and a depth information generation unit that generates depth information of the object using the second optical signal. The light emitting unit includes a light source and a microlens array disposed on the light source. The microlens array includes a first microlens and a plurality of second microlenses that most closely surround the first microlens. The plurality of second microlenses have different FoIs from each other, and the first microlens and the plurality of second microlenses have different FoIs from each other.

[0041] At least one of the aspherical shape, radius of curvature, and conic constant of the plurality of second microlenses may be different from each other.

[0042] At least one of the aspherical shape, radius of curvature, and conic constant of the first microlens and the plurality of second microlenses may be different from each other.

[0043] A camera device according to another embodiment of the present invention includes a light emitting unit that irradiates an object with a first optical signal, a light receiving unit that receives a second optical signal reflected from the object, and a depth information generation unit that generates depth information of the object using the second optical signal. The light emitting unit includes a light source and a microlens array disposed on the light source. The microlens array includes a plurality of microlenses. At least 50% of the plurality of microlenses have different fields of interest (FoIs) from each other in a first direction, or at least 50% of the plurality of microlenses have different FoIs from each other in a second direction perpendicular to the first direction.

[0044] At least one of the aspherical shape, the radius of curvature, and the conic constant of at least 50% of the plurality of microlenses may be different from each other.

[0045] The microlens array includes a first region including a plurality of first microlenses having a first average diameter, and a second region including a plurality of second microlenses having a second average diameter different from the first average diameter and surrounding the first region. The diameters of the plurality of first microlenses are different from each other, the diameters of the plurality of second microlenses are different from each other, and the plurality of first microlenses and the plurality of second microlenses can have different FoIs from each other.

[0046] The plurality of microlenses includes a first microlens group disposed in a first region including the center of the microlens array, and a second microlens group disposed in a second region disposed around the first region and including an edge. The lenses of the first microlens group may have at least one of an aspherical shape, a radius of curvature, and a conic constant different from each other.

[0047] The lenses of the second microlens group may have at least one of an aspherical shape, a radius of curvature, and a conic constant different from each other.

[0048] At least a part of the plurality of microlenses having the same curvature radius and conic constant in the first direction may have at least one of the curvature radius and the conic constant different in the second direction, or at least a part of the plurality of microlenses having the same curvature radius and conic constant in the second direction may have at least one of the curvature radius and the conic constant different in the first direction.

[0049] An optical output device according to another embodiment of the present invention includes a light source; and a microlens array disposed on the light source, the microlens array including a first microlens; and a plurality of second microlenses that most closely surround the first microlens, the FoI of the first microlens and the plurality of second microlenses being different from each other, and the FoI between the plurality of second microlenses being different from each other.

Effect of the Invention

[0050] According to an embodiment of the present invention, it is possible to obtain a camera device with a high uniformity of the surface illumination pattern, safe for the user's eyes, and capable of extracting depth information with high precision and resolution.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0084] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0085] However, the technical idea of the present invention is not limited to a part of the described embodiments, and can be realized in various different forms. Within the scope of the technical idea of the present invention, one or more of the components among the embodiments can be selectively combined or replaced and used.

[0086] In addition, the terms (including technical and scientific terms) used in the embodiments of the present invention can be construed to have a meaning generally understood by those of ordinary skill in the technical field to which the present invention pertains, unless clearly defined and described otherwise. Terms that are generally used like those defined in a dictionary can be interpreted considering their meaning in the context of the related art.

[0087] Also, the terms used in the embodiments of the present invention are for the purpose of explaining the embodiments and are not intended to limit the present invention.

[0088] In this specification, the singular form can also include the plural form unless otherwise specifically stated in the text. When it is described as "at least one (or one or more) of A and (or) B, C", it can include one or more of all combinations that can be combined with A, B, and C.

[0089] In addition, when describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. can be used.

[0090] Such terms are only for distinguishing the component from other components and are not limited to the essence, order, or procedure of the corresponding component by such terms.

[0091] In addition, when a component is described as being "connected", "coupled", or "joined" to another component, that component can include not only the case where it is directly connected or joined to the other component, but also the case where it is "connected", "coupled", or "joined" by another component or other components intervening between that component and the other component.

[0092] In addition, when it is described that it is formed or arranged "above (upper part) or below (lower part)" of each component, "above (upper part) or below (lower part)" includes not only the case where two components are in direct contact with each other, but also the case where one or more other components are formed or arranged between the two components. Further, when expressed as "above (upper part) or below (lower part)", it can include not only the upward direction but also the downward direction with respect to one component.

[0093] The camera device according to an embodiment of the present invention can mean a camera that extracts depth information using a ToF (Time of Flight) function. Therefore, the camera device can be used interchangeably with a ToF camera device, a ToF camera module, a ToF camera, etc.

[0094] FIG. 1 is a block diagram of a camera device according to an embodiment of the present invention, and FIG. 2 is a drawing for explaining an output optical signal output by the camera device according to an embodiment of the present invention.

[0095] Referring to FIG. 1, a camera device 1000 according to an embodiment of the present invention includes a light emitting unit 100, a light receiving unit 200, a depth information generating unit 300, and a control unit 500.

[0096] The light emitting unit 100 can generate and output an output optical signal in the form of a pulse wave or a continuous wave. The continuous wave may be in the form of a sinusoid wave or a squared wave. By generating the output optical signal in the form of a pulse wave or a continuous wave, the camera device 1000 can detect the time difference or phase difference between the output optical signal output from the light emitting unit 100 and the input optical signal input to the light receiving unit 200 after being reflected from the object. In this specification, the output light means the light output from the light emitting unit 100 and incident on the object, and the input light can mean the light output from the light emitting unit 100, reaching the object, and then being reflected from the object and input to the light receiving unit 200. From the perspective of the object, the output light can be the incident light, and the input light can be the reflected light.

[0097] Referring to FIG. 2(a), the light emitting unit 100 can generate optical pulses at a constant period. The light emitting unit 100 has a predetermined pulse repetition period (t modulation ) and can generate optical pulses having a predetermined pulse width (t pulse ).

[0098] Referring to FIG. 2(b), a certain number of optical pulses generated by the light emitting unit 100 can be grouped to form one phase pulse. The light emitting unit 100 can generate a phase pulse having a predetermined phase pulse period (t phase ) and a predetermined phase pulse width (t exposure ). The phase pulse width can also be referred to as t illumination or t integration . Here, one phase pulse period (t phase ) can correspond to one sub-frame. The sub-frame can be called a phase frame. The phase pulse periods can be grouped in a predetermined number. The method of grouping four phase pulse periods (t phase ) can be called a 4-phase method. The method of grouping eight periods (t pphase ) can be called an 8-phase method.

[0099] Referring to FIG. 2(c), a certain number of phase pulses generated by the light emitting unit 100 can be grouped to form one frame pulse. The light emitting unit 100 can generate a frame pulse having a predetermined frame pulse period (t frame ) and a predetermined frame pulse width (t phase group(sub-frame group) ). Here, one frame pulse period (t frame ) can correspond to one frame. Therefore, when shooting an object at 10 FPS, there are 10 frame pulse periods (t frame) can be repeated. In the 4-phase method, one frame can include 4 sub-frames. That is, one frame can be generated through 4 sub-frames. In the 8-phase method, one frame can include 8 sub-frames. That is, one frame can be generated through 8 sub-frames.

[0100] In the above, for the purpose of explanation, the terms of optical pulse, phase pulse, and frame pulse are used, but it is not limited thereto.

[0101] Referring also to FIG. 1, the light emitting unit 100 can include a light source 110 and a diffusion member 120. The light source 110 generates and outputs light. The light generated by the light source 110 may be infrared light having a wavelength of 770 to 3000 nm. Or the light generated by the light source 110 may be visible light having a wavelength of 380 to 770 nm. The light source 110 can utilize a light emitting diode (LED), and can have a form in which a plurality of light emitting diodes are arranged in a certain pattern. Not only that, the light source 110 may include an organic light emitting diode (OLED) or a laser diode (LD). Or, the light source 110 may be a VCSEL (Vertical Cavity Surface Emitting Laser). The VCSEL is one of the laser diodes that converts an electrical signal into an optical signal, and can output a wavelength of about 800 to 1000 nm, for example, a wavelength of about 850 nm or about 940 nm. The light source 110 repeatedly turns on and off at a certain time interval to generate an output optical signal in a pulse waveform or a continuous waveform. The certain time interval may be the frequency of the output optical signal.

[0102] After receiving the light output from the light source 110, the diffusion member 120 can diffract and output the received light. The diffusion member 120 can condense light and convert it into parallel light. The diffusion member 120 may be a Micro Lens Array (MLA).

[0103] Although not shown in the figure, the light emitting unit 100 may further include an additional lens assembly. The lens assembly (not shown) can condense the light output from the light source 110 and output the condensed light to the outside. The lens assembly can be disposed at a distance from the light source 110 above the light source 110. Here, above the light source 110 can mean the side from which light is output from the light source 110. The lens assembly may include at least one lens. When the lens assembly includes a plurality of lenses, each lens can be aligned with respect to the central axis to form an optical system. Here, the central axis may be the same as the optical axis of the optical system.

[0104] The light receiving unit 200 can receive the light reflected from the object. The light receiving unit 200 can receive the optical signal reflected from the object. At this time, the received optical signal may be the optical signal output by the light emitting unit 100 reflected from the object.

[0105] The light-receiving unit 200 may include a lens assembly, a filter, and a sensor for receiving an optical signal. The optical signal reflected from the object can pass through the lens assembly. The optical axis of the lens assembly can be aligned with the optical axis of the sensor. The filter can be disposed between the lens assembly and the sensor. The filter can be disposed on the optical path between the object and the sensor. The filter can filter light having a predetermined wavelength range. The filter can transmit light in a specific wavelength band of light. The filter can pass light of a specific wavelength. For example, the filter can pass light in the infrared band and block light other than the infrared band. The sensor can sense light. The sensor can receive an optical signal. The sensor may be an image sensor that senses an optical signal. The sensor can sense an optical signal and output it as an electrical signal. The sensor can sense light having a wavelength corresponding to the wavelength of the light output by the light-emitting element. For example, the sensor can sense light in the infrared band.

[0106] For example, the sensor can receive an input optical signal synchronized with the blinking period of the light source 110. Specifically, the sensor can receive light in phase and out of phase with the output optical signal output from the light source 110, respectively. That is, the sensor can repeatedly perform the step of receiving the input optical signal when the light source is on and the step of receiving the input optical signal when the light source is off. The sensor can generate an electrical signal corresponding to each reference signal using a plurality of reference signals having different phase differences from each other. The frequency of the reference signal can be set to be the same as the frequency of the output optical signal output from the light source 110. Therefore, when the light source 110 generates an output optical signal at a plurality of frequencies, the sensor generates an electrical signal using a plurality of reference signals corresponding to each frequency. The electrical signal can include information regarding the amount of charge or voltage corresponding to each reference signal.

[0107] The reference signals according to the embodiments of the present invention may be four (C1 to C4, not shown). Although each reference signal (C1 to C4) has the same frequency as the output optical signal, they can have a phase difference of 90 degrees from each other. One of the four reference signals (C1) can have the same phase as the output optical signal. The phase of the input optical signal is delayed by the distance that the output optical signal travels after being incident on the object and then reflected back. The sensor mixes the input optical signal and each reference signal respectively. Then, the sensor can generate electrical signals for each reference signal.

[0108] The sensor can be configured with a structure in which a plurality of pixels are arranged in a grid form. The sensor may be a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. Also, the sensor can include a ToF sensor that receives IR light reflected from an object and measures the distance using time or phase difference. For example, each pixel can include an In phase receiving unit that receives the input optical signal with the same phase as the waveform of the output light and an Out phase receiving unit that receives the input optical signal with the opposite phase to the waveform of the output light. When the In phase receiving unit and the Out phase receiving unit are activated with a time difference, a difference in the amount of light received by the In phase receiving unit and the Out phase receiving unit occurs depending on the distance to the object, and the distance to the object can be calculated using this difference.

[0109] The light receiving unit 200 and the light emitting unit 100 may be arranged side by side. The light receiving unit 200 may be arranged beside the light emitting unit 100. The light receiving unit 200 may be arranged in the same direction as the light emitting unit 100.

[0110] The depth information generation unit 300 can generate depth information of an object using the input optical signal input to the light receiving unit 200. For example, the depth information generation unit 300 can calculate the depth information of the object using the flight time from when the output optical signal output from the light emitting unit 100 is reflected by the object until it is input to the light receiving unit 200. For example, the depth information generation unit 300 calculates the phase difference between the output optical signal and the input optical signal using the electrical signal received from the sensor, and calculates the distance between the object and the camera device 1000 using the calculated phase difference.

[0111] Specifically, the depth information generation unit 300 can calculate the phase difference between the output optical signal and the input optical signal using the charge amount information of the electrical signal.

[0112] As detailed above, four electrical signals can be generated for each frequency of the output optical signal. Therefore, the depth information generation unit 300 uses the following mathematical formula 1 to calculate the phase difference (t d ) between the output optical signal and the input optical signal.

[0113]

Equation

[0114] Here, Q1 to Q4 are the charge amounts of the four electrical signals respectively. Q1 is the charge amount of the electrical signal corresponding to the reference signal having the same phase as the output optical signal. Q2 is the charge amount of the electrical signal corresponding to the reference signal having a phase 180 degrees later than the output optical signal. Q3 is the charge amount of the electrical signal corresponding to the reference signal having a phase 90 degrees later than the output optical signal. Q4 is the charge amount of the electrical signal corresponding to the reference signal having a phase 270 degrees later than the output optical signal.

[0115] Then, the depth information generation unit 300 can calculate the distance between the object and the camera device 100 by using the phase difference between the output optical signal and the input optical signal. At this time, the depth information generation unit 300 can calculate the distance (d) between the object and the camera device 1000 by using the following mathematical formula 2.

[0116]

Equation

[0117] Here, c is the speed of light, and f is the frequency of the output light.

[0118] The control unit 500 controls the driving of the light emitting unit 100, the light receiving unit 200, and the depth information generation unit 300. The depth information generation unit 300 and the control unit 500 can be realized in the form of a PCB (printed circuit board). Also, the depth information generation unit 300 and the control unit 500 can be realized in other configurations. Alternatively, the control unit 500 can also be included in the terminal where the camera device 1000 according to the embodiment of the present invention is arranged. For example, the control unit 500 can be realized in the form of an application processor (AP) of a smartphone on which the camera device 1000 according to the embodiment of the present invention is mounted.

[0119] FIG. 3 is a schematic diagram of the light emitting unit according to an embodiment of the present invention.

[0120] Referring to FIG. 3, the light emitting unit 100 according to an embodiment of the present invention includes a light source 110 and a diffusion member 120.

[0121] According to an embodiment of the present invention, the light source 110 can include a plurality of light emitting elements 112. Specifically, the light source 110 can be realized in an array form in which a plurality of light emitting elements 112 are arranged on a substrate 111 according to a predetermined rule. The substrate 111 includes a first surface and a second surface, and a plurality of light outlets (apertures) can be formed on the first surface of the substrate 111, and the diffusion member 120 can be arranged on the substrate 111 corresponding to the plurality of light outlets. The light source 110 outputs light through the light outlet, and the light can be output at a predetermined divergence angle. The plurality of light emitting elements 112 may be vertical-cavity surface-emitting lasers (VCSELs).

[0122] The diffusion member 120 can be divided into a main body portion 121 and a plurality of microlenses 122. Specifically, the diffusion member 120 may have a shape in which a plurality of microlenses 122 are arranged on the main body portion 121 according to a predetermined rule. The diffusion member 120 can be integrally formed with the main body portion 121 and the plurality of microlenses 122. At this time, the main body portion 121 and the microlenses 122 can be formed of the same material as each other. The main body portion 121 may be in the shape of a plate. Accordingly, the diffusion member 120 may be a microlens array (MLA).

[0123] The diffusion member 120 can be divided into a first surface for inputting light from the light source 110 and a second surface for outputting light. The second surface of the diffusion member 120 can include a horizontal surface or a curved surface, and a plurality of microlenses 122 can be arranged on the first surface of the diffusion member 120.

[0124] The plurality of microlenses 122 can have a predetermined diameter. The diameter of the plurality of microlenses 122 can be set such that the maximum value among the light beam concentration degrees of the plurality of microlenses does not exceed a predetermined value. Here, the light beam concentration degree can mean the ratio of the total energy output by the light source 110 to the light beam incident on one microlens. According to this, the energy concentrated on one microlens can be dispersed to enhance the safety for the user's eyes. Here, the user can be an object of the camera device 1000 or a person located around the camera device 1000, etc.

[0125] The diffusing member 120 converts the laser beam output by the light emitting element 112 into a surface illumination pattern. Here, the surface illumination pattern can be mixed with a flood illumination pattern, a surface light source pattern, etc. in a form in which light spreads uniformly within a predetermined region. Here, being uniform can mean that light spreads continuously in space. In the case of the surface illumination pattern, since light spreads uniformly (continuously) in space, when irradiating an object with the light of the surface illumination pattern, there is an advantage that depth information with high resolution can be obtained.

[0126] At this time, when the size of the diffusing member 120, that is, the plurality of microlenses forming the microlens array, is uniform, reinforcement interference or destructive interference may occur due to the coherent characteristic of the laser beam, and the homogeneity of the surface illumination pattern may decrease.

[0127] More specifically, when a laser beam having a coherent characteristic passes through a slit having a certain grating period, diffraction can occur according to Mathematical Formula 3. That is, the phase of light of a specific wavelength meets the grating period to cause reinforcement interference and destructive interference, and diffraction occurs. A phenomenon that brightens or darkens at a specific angle can occur due to the reinforcement interference, and this can be defined as the diffraction order.

[0128]

Equation

[0129] Here, d is the grating period, θ is the diffraction angle, m is the diffraction order, and λ means the wavelength.

[0130] In addition, as the number of grating periods of the slit increases, the reinforcing interference and the canceling interference are further strengthened. Therefore, the light intensity at the diffraction angle θ is as shown in Mathematical Formula 4.

[0131]

Equation

[0132] Here, I is the light intensity of the electric field, d is the grating period, N is the number of grating periods per 1 mm (d / 1 mm), θ is the diffraction angle, and λ means the wavelength.

[0133] In an embodiment of the present invention, through the design of the microlens forming the diffusion member, the deviation of the light intensity I is reduced by Mathematical Formula 4, and the uniformity of the surface illumination pattern is increased.

[0134] According to an embodiment of the present invention, the diffusion member can be divided into a plurality of regions, and can include microlenses having different diameters for each region.

[0135] FIG. 4 is a plan view of a diffusion member according to an embodiment of the present invention, FIGS. 5 to 6 are drawings for explaining the diameters of the microlenses forming the diffusion member according to an embodiment of the present invention, and FIG. 7 is a cross-sectional view of a diffusion member and a light source according to an embodiment of the present invention.

[0136] Referring to FIGS. 4 to 7, a diffusion member 400 according to an embodiment of the present invention includes a first region 410R including a plurality of first microlenses 410 having a first diameter P1, a second region 420R surrounding the first region 410R and including a plurality of second microlenses 420 having a second diameter P2, and a third region 430R surrounding the second region 420R and including a plurality of third microlenses 430 having a third diameter P3. Here, for the same content as the description of the diffusion member 120 described with reference to FIGS. 1 to 3 in the description of the diffusion member 400, redundant descriptions are omitted.

[0137] Here, the first region 410R may be a region including the center of the diffusion member 400.

[0138] According to an embodiment of the present invention, the first region 410R includes a plurality of first microlenses 410 arranged along a first direction, the second region 420R includes a plurality of second microlenses 420 arranged along the first direction, and the third region 430R includes a plurality of third microlenses 430 arranged along the first direction. Here, the first direction may correspond to a direction intersecting the optical axis direction. Also, a plurality of first microlenses 410 are arranged along a second direction perpendicular to the first direction in the first region 410R, a plurality of second microlenses 420 are arranged along the second direction in the second region 420R, and a plurality of third microlenses 430 are arranged along the second direction in the third region 430R. At this time, the plurality of first microlenses 410 arranged in the outermost row and outermost column of the first region 410R are arranged adjacent to the plurality of second microlenses 420 arranged in the second region 420R, and the plurality of second microlenses 420 arranged in the second region 420R can be arranged adjacent to the plurality of third microlenses 430 arranged in the third region 430R. The plurality of second microlenses 420 can be arranged in a single row so as to surround the outermost contour of the first region 410R, and the plurality of third microlenses 430 can be arranged in a single row so as to surround the second region 420R. As a result, on one side surface of each second microlens 420 in a direction perpendicular to the direction in which the plurality of second microlenses 420 are arranged, a first microlens 410 can be arranged, and on the other side surface, a third microlens 430 can be arranged. That is, on both side surfaces of each second microlens 420 in a direction perpendicular to the direction in which the plurality of second microlenses 420 are arranged, second microlenses 420 do not necessarily need to be arranged. Similarly, on both side surfaces of each third microlens 430 in a direction perpendicular to the direction in which the plurality of third microlenses 430 are arranged, third microlenses 430 do not necessarily need to be arranged. The distance of the diffusing member 400, that is, from the center of the microlens array to the second microlens 420, may be larger than the distance from the center of the microlens array to the first microlens, and the distance from the center of the microlens array to the third microlens 430 may be larger than the distance from the center of the microlens array to the second microlens 420.

[0139] In this specification, the description is centered around the first to third regions 410R to 430R including the first to third microlenses with the first to third diameters, but this is for convenience of description and is not limited thereto. Embodiments of the present invention can be extended to a fourth region surrounding the third region 430R and including a plurality of fourth microlenses having a fourth diameter, a fifth region surrounding the fourth region and including a plurality of fifth microlenses having a fifth diameter, and the like.

[0140] Here, the first diameter P1, the second diameter P2, and the third diameter P3 can be used interchangeably with the first pitch P1, the second pitch P2, and the third pitch P3, respectively. Here, the diameter can mean the length of the microlens in the first direction or the second direction. However, the diameter can also mean the length of the microlens in a direction other than the first and second directions.

[0141] According to an embodiment of the present invention, the first region 410R, the second region 420R, and the third region 430R are arranged within a region a defined by Equation 5.

[0142]

Equation

[0143] Here, a is the width of the region where the light intensity reaches 1 / e of the maximum light intensity, D means the distance from the light source 110 to the diffusing member 400, and θ can be defined as the angle at which the light intensity of 1 / e of the maximum light intensity of the light source 110 is output. 2 times the light intensity reaches, and θ can be defined as the angle at which the light intensity of 1 / e of the maximum light intensity of the light source 110 is output. 2 times the light intensity is output.

[0144] In this connection, referring to FIG. 7, the light source 110 and the diffusion member 400 are arranged at a predetermined distance (D) from each other. Further, the light emitting element 112 outputs light at a predetermined angle (θ). When a virtual normal perpendicular to the substrate 111 is connected from the center of the light emitting element 112, the angle (θ / 2) formed by the virtual normal and the light is half of the divergence angle (θ) of the light output by the light emitting element 112. The plurality of light emitting elements 112 may all have the same standard, and the divergence angles (θ) at which the plurality of light emitting elements 112 output light may be the same as each other.

[0145] For example, the light emitting element 112 can emit a predetermined amount of energy from -20 degrees to 20 degrees with respect to the optical axis. However, it can be seen that the amount of energy is almost zero at angles of -15 degrees, +15 degrees, or angles of -15 degrees or less or 15 degrees or more. That is, most of the energy exists within a predetermined angle with respect to the optical axis of the light emitting element. Therefore, it is inefficient to set the divergence angle of the light emitting element to all angles where the amount of energy is not zero, and it is efficient to set the divergence angle of the light emitting element to the angle at which a certain amount or more of energy is diverged. As a result, the divergence angle of the light source 110 can be set to the angle at which the light intensity is 1 / e 2 times the maximum light intensity of the light source 110, and the region a defined by Equation 5 can be referred to as the effective light region.

[0146] At this time, the first diameter P1, the second diameter P2, and the third diameter P3 may be different from each other. In this way, when the first region 410R, the second region 420R, and the third region 430R in which the diameters of the microlenses are different from each other are arranged within the effective light region, the energy of the output light can be dispersed to enhance the safety for the user's eyes, and a decrease in homogeneity due to interference can also be prevented.

[0147] According to an embodiment of the present invention, the number of microlenses included in at least one of the first to third regions 410R, 420R, 430R has a correlation with the diameter of the microlenses included in at least one of the first to third regions 410R, 420R, 430R and the diameter of the microlenses included in another region surrounding at least one of the first to third regions 410R, 420R, 430R. According to an embodiment of the present invention, the number and diameter of the microlenses included in at least one of the first to third regions 410R, 420R, 430R have a correlation with the diameter of the microlenses included in another region surrounding at least one of the first to third regions 410R, 420R, 430R. The number of microlenses by region according to an embodiment of the present invention can be represented by Mathematical Formula 6.

[0148]

Number

[0149] Here, P n is the diameter of the microlenses arranged in the nth region, and P n+1 is the diameter of the microlenses arranged in the (n + 1)th region, and x n is the number of microlenses arranged along the first direction or the number of microlenses arranged along the second direction in the nth region. x n does not mean the total number of all microlenses included in the nth region. For example, x1 may be 4 microlenses arranged along the first direction or the second direction in the first region, x2 may be 5 microlenses arranged along the first direction or the second direction in the second region, and x3 may be 6 microlenses arranged along the first direction or the second direction in the third region.

[0150] According to this, the number of microlenses included in the n-th region can have a correlation with the diameter of the microlenses included in the n-th region and the diameter of the microlenses included in the (n + 1)-th region surrounding the n-th region. The number and diameter of the microlenses included in the n-th region can have a correlation with the diameter of the microlenses included in the (n + 1)-th region surrounding the n-th region.

[0151] For example, the number of first microlenses 410 included in the first region 410R can have a correlation with the first diameter P1 of the first microlenses 410 included in the first region 410R and the second diameter P2 of the second microlenses 420 included in the second region 420R. The number and the first diameter P1 of the first microlenses 410 included in the first region 410R can have a correlation with the second diameter P2 of the second microlenses 420 included in the second region 420R. Also, the number of second microlenses 420 included in the second region 420R can have a correlation with the second diameter P2 of the second microlenses 420 included in the second region 420R and the third diameter P3 of the third microlenses 430 included in the third region 430R. The number and the second diameter P2 of the second microlenses 420 included in the second region 420R can have a correlation with the third diameter P3 of the third microlenses 430 included in the third region 430R.

[0152] For example, the product of the first diameter P1 and the number of first microlenses 410 arranged along the first direction may be the same as the product of a number that is 1 less than the number of first microlenses 410 arranged along the first direction and the second diameter P2, and the product of the second diameter P2 and the number of second microlenses 420 arranged along the first direction may be the same as the product of a number that is 1 less than the number of second microlenses 420 arranged along the first direction and the third diameter P3. According to this, it is possible to minimize the constructive interference and destructive interference due to the overlap of diffraction angles due to the diffraction order for each region, and the arrangement of the microlens array is easy.

[0153] Table 1 shows an example of a microlens array according to an embodiment of the present invention under the condition that D>5.7 mm, which is the distance from the light source 110 to the diffusion member 400.

[0154] [Table 1]

[0155] Here, n is the order of the region, the diameter is the diameter of the microlens for each region, and the number is the number of microlenses repeatedly arranged along the first direction or the number of microlenses repeatedly arranged along the second direction.

[0156] For example, 4 microlenses with a diameter of 300 μm in the first region can be arranged in a row along the first direction, 5 microlenses with a diameter of 400 μm in the second region can be arranged in a row along the first direction, 6 microlenses with a diameter of 500 μm in the third region can be arranged in a row along the first direction, 7 microlenses with a diameter of 600 μm in the fourth region can be arranged in a row along the first direction, 8 microlenses with a diameter of 700 μm in the fifth region can be arranged in a row along the first direction, and 9 microlenses with a diameter of 800 μm in the sixth region can be arranged in a row along the first direction.

[0157] Referring to Equation 6, when n = 1, the diameter is 300 μm, and when n = 2, the diameter is 400 μm. In this case, the number of microlenses arranged in a row along the first direction when n = 1 can be 4. Similarly, when n = 2, the diameter is 400 μm, and when n = 3, the diameter is 500 μm. In this case, the number of microlenses arranged in a row along the first direction when n = 2 can be 5.

[0158] Also, when n = 6, the diameter is 800 μm, and when n = 7, the diameter is 900 μm. In this case, the number of microlenses arranged in a row along the first direction when n = 6 can be 9.

[0159] When arranging the microlens array under such conditions, it is possible to minimize the constructive interference and destructive interference caused by the overlap of diffraction angles due to the diffraction order for each region. Since three or more types of microlenses with different diameters are arranged within the effective light region, it can be safer for the user's eyes.

[0160] Table 2 shows an example of the microlens array according to an embodiment of the present invention under the condition that D>1.2 mm, which is the distance from the light source 110 to the diffusion member 400.

[0161]

Table 2

[0162] Here, n is the order of the region, the diameter is the diameter of the microlens for each region, and the number is the number of microlenses repeatedly arranged along the first direction or the number of microlenses repeatedly arranged along the second direction. It can be seen from Table 2 that it is designed to satisfy Mathematical Formula 6. Under such conditions, when arranging the microlens array, it is possible to minimize the constructive interference and destructive interference caused by the overlap of diffraction angles due to the diffraction order for each region. Since three or more types of microlenses with different diameters are arranged within the effective light region, it can be safer for the user's eyes.

[0163] Table 3 shows an example of the microlens array according to an embodiment of the present invention under the condition that D>0.35 mm, which is the distance from the light source 110 to the diffusion member 400.

[0164]

Table 3

[0165] Here, n is the order of the regions, the diameter is the diameter of the microlenses for each region, and the number is the number of microlenses repeatedly arranged along the first direction or the number of microlenses repeatedly arranged along the second direction. It can also be seen from Table 3 that it is designed to satisfy Mathematical Formula 6. Under such conditions, when arranging the microlens array, it is possible to minimize the constructive interference and destructive interference due to the overlap of diffraction angles according to the diffraction order for each region. Since three or more types of microlenses with different diameters are arranged within the effective light region, it can be safer for the user's eyes.

[0166] Referring to Tables 1 to 3, it can be seen that the diameter of the microlenses changes depending on the distance D between the light source 110 and the diffusing member 400. Here, the distance D between the light source 110 and the diffusing member 400 may be the vertical distance between the first surface of the light source 110 and the first surface of the diffusing member 400. The first surface of the light source 110 means the surface where the light exit is arranged. The first surface of the diffusing member 400 means the surface where light from the light source 110 is input for each of the plurality of microlenses 410, 420, 430. Specifically, since the plurality of microlenses 410, 420, 430 are arranged in an embossing form on the first surface of the diffusing member 400, the first surface of the diffusing member 400 can be meant as the surface connecting the points through which the optical axes pass for each of the plurality of microlenses 410, 420, 430. Therefore, the separation distance between the diffusing member 400 and the light source 110 may also be the vertical distance between the first surface of the light source 110 and a point through which the optical axes of the microlenses 410, 420, 430 pass.

[0167] As illustrated in Table 1, when D > 5.7 mm, it can be seen that the diameter of the microlens is several hundred μm, for example, 300 μm or more, for example, 300 μm to 800 μm. As illustrated in Table 2, when D > 1.2 mm, it can be seen that the diameter of the microlens is several tens of μm to several hundred μm, for example, 50 μm or more, for example, 50 μm to 120 μm. As illustrated in Table 3, when D > 0.35 mm, it can be seen that the diameter of the microlens is several tens of μm, for example, 20 μm or more, for example, 20 μm to 70 μm. Thus, when the diameter of the microlens changes depending on the distance D between the light source 110 and the diffusion member 400, the light flux concentration with respect to a specific microlens can be reduced, so it can be safe for the user's eyes.

[0168] On the other hand, according to an embodiment of the present invention, the plurality of first microlenses 410 included in the first region 410R, the plurality of second microlenses 420 included in the second region 420R, and the plurality of third microlenses 430 included in the third region 430R can be projected in the direction toward the light source 110. In this specification, the direction from the diffusion member 400 toward the light source 110 can be referred to as a third direction perpendicular to the first direction and the second direction, which are the planar directions of the diffusion member 400. Here, the third direction may be the same as the optical axis direction of the first to third microlenses 410, 420, and 430.

[0169] At this time, the protruding height (h1) of the plurality of first microlenses 410, the protruding height (h2) of the plurality of second microlenses 420, and the protruding height (h3) of the plurality of third microlenses 430 may be different from each other. According to this, since the boundaries of the first region 410R, the second region 420R, and the third region 430R are determined by the protruding height of each microlens, the periodicity of the lattice is disrupted, and the reinforcement interference and cancellation interference due to the overlap of the diffraction angles according to the diffraction order for each region can be minimized.

[0170] At this time, the plurality of first microlenses 410 included in the first region 410R, the plurality of second microlenses 420 included in the second region 420R, and the plurality of third microlenses 430 included in the third region 430R can each have an aspherical shape. For example, the aspherical shapes of the first microlenses 410, the second microlenses 420, and the third microlenses 430 can be defined by the image height, the radius of curvature, and the conic constant. For example, the aspherical shapes of the first microlenses 410, the second microlenses 420, and the third microlenses 430 can be defined by Mathematical Formula 7.

[0171]

Equation

[0172] Here, Z is the aspherical shape of the lens, h is the image height, R is the radius of curvature, and K is the conic constant.

[0173] Since the microlens array is arranged two-dimensionally, the aspherical shapes of the first microlenses 410, the second microlenses 420, and the third microlenses 430 can be defined by Mathematical Formula 8.

[0174]

Equation

[0175] Here, x is the X-axis image height, y is the Y-axis image height, Rx is the X-axis radius of curvature, Ry is the Y-axis radius of curvature, Kx is the x-axis conic constant, and Ky is the Y-axis conic constant.

[0176] According to this, the FoI of the laser beam passing through the microlens array can be defined, and the light flux concentration degree of a specific microlens can be set so as not to exceed a predetermined value.

[0177] The simulation results according to the embodiments and comparative examples of the present invention will be described below.

[0178] FIG. 8(a) is a plan view of a 3D drawing of a microlens array according to a comparative example, FIG. 8(b) is a perspective view of a 3D drawing of a microlens array according to a comparative example, FIG. 9 is a Monte Carlo Ray tracing simulation result of a microlens array according to a comparative example, FIG. 10(a) is an FDTD simulation result of a microlens array according to a comparative example, and FIG. 10(b) is an enlarged view of a partial region of FIG. 10(a).

[0179] FIG. 11(a) is a plan view of a 3D drawing of a microlens array according to an embodiment, FIG. 11(b) is a perspective view of a 3D drawing of a microlens array according to an embodiment, FIG. 12 is a Monte Carlo Ray tracing simulation result of a microlens array according to an embodiment, FIG. 13(a) is an FDTD simulation result of a microlens array according to an embodiment, and FIG. 13(b) is an enlarged view of a partial region of FIG. 13(a).

[0180] In the microlens array according to the comparative example, a plurality of microlenses are arranged in an array shape, and the plurality of microlenses are all designed to have the same diameter.

[0181] Referring to FIGS. 8(a), 8(b), 9, 10(a) and 10(b), it can be seen that in the Monte Carlo ray tracing simulation result of the microlens array according to the comparative example, the edge angle of the peripheral portion is sharply formed, and in the FDTD simulation result of the microlens array according to the comparative example, strong reinforcing interference due to diffraction occurs.

[0182] On the other hand, referring to FIGS. 11(a), 11(b), 12, 13(a) and 13(b), it can be seen that in the Monte Carlo ray tracing simulation results of the microlens array according to the embodiment, the edge angle of the peripheral portion becomes duller than that of the comparative example, and in the FDTD simulation results of the microlens array according to the embodiment, the reinforcing interference due to diffraction is significantly weakened compared to the comparative example.

[0183] FIG. 14 is a plan view of a diffusion member according to another embodiment of the present invention, FIGS. 15 to 16 are drawings for explaining the diameters of microlenses forming the diffusion member according to another embodiment of the present invention, FIG. 17 is an enlarged view of the first region 710R in FIG. 15, and FIG. 18 is a cross-sectional view of a diffusion member and a light source according to another embodiment of the present invention. For the sake of convenience of explanation, redundant explanations will be omitted for the same content as that described through FIGS. 1 to 13.

[0184] Referring to FIGS. 14 to 18, a diffusion member 700 according to another embodiment of the present invention includes a first region 710R including a plurality of first microlenses 710 having a first average diameter AP1, a second region 720R surrounding the first region 710R and including a plurality of second microlenses 720 having a second average diameter AP2, and a third region 730R surrounding the second region 720R and including a plurality of third microlenses 730 having a third average diameter AP3. Here, redundant explanations will be omitted for the same content as that described for the diffusion member 120 with reference to FIGS. 1 to 3 in the description of the diffusion member 700.

[0185] Here, the first region 710R may be a region including the center of the diffusion member 700. The center of the diffusion member 700 may mean the center of the microlens array of the diffusion member 700.

[0186] According to an embodiment of the present invention, the first region 710R includes a plurality of first microlenses 710 arranged along a first direction, the second region 720R includes a plurality of second microlenses 720 arranged along the first direction, and the third region 730R includes a plurality of third microlenses 730 arranged along the first direction. Here, the first direction may correspond to a direction intersecting the optical axis direction. Also, in the first region 710R, a plurality of first microlenses 710 are arranged along a second direction that is perpendicular to the first direction and intersects the optical axis direction, in the second region 720R, a plurality of second microlenses 720 are arranged along the second direction, and in the third region 730R, a plurality of third microlenses 730 are arranged along the second direction. At this time, a plurality of first microlenses 710 arranged in the outermost row and outermost column of the first region 710R may be arranged adjacent to a plurality of second microlenses 720 arranged in the second region 720R, and a plurality of second microlenses 720 arranged in the second region 720R may be arranged adjacent to a plurality of third microlenses 730 arranged in the third region 730R. The plurality of second microlenses 720 may be arranged in a row so as to surround the outermost outline of the first region 710R, and the plurality of third microlenses 730 may be arranged in a row so as to surround the second region 720R. As a result, on one side surface of each second microlens 720 in a direction perpendicular to the direction in which the plurality of second microlenses 720 are arranged, a first microlens 710 may be arranged, and on the other side surface, a third microlens 730 may be arranged. That is, on both side surfaces of each second microlens 720 in a direction perpendicular to the direction in which the plurality of second microlenses 720 are arranged, second microlenses 720 may not be arranged. Similarly, on both side surfaces of each third microlens 730 in a direction perpendicular to the direction in which the plurality of third microlenses 730 are arranged, third microlenses 730 may not be arranged. The distance of the diffusing member 700, that is, from the center of the microlens array to the second microlens 720, may be greater than the distance from the center of the microlens array to the first microlens 710, and the distance from the center of the microlens array to the third microlens 730 may also be greater than the distance from the center of the microlens array to the second microlens 720.

[0187] In this specification, the description is centered around the first to third regions 710R to 730R including the first to third microlenses with the first to third average diameters, but this is for convenience of description and is not limited thereto. Embodiments of the present invention can be extended to a fourth region surrounding the third region 730R and including a plurality of fourth microlenses having a fourth average diameter, a fifth region surrounding the fourth region and including a plurality of fifth microlenses having a fifth average diameter, and the like.

[0188] Here, the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3 can be used interchangeably with the first average pitch AP1, the second average pitch AP2, and the third average pitch AP3, respectively. Here, the diameter can mean the length of the microlens in the first direction or the second direction. However, the diameter can also mean the length of the microlens in a direction other than the first and second directions. For example, the diameter can also mean the length of the microlens in the third direction which is the first direction, the second direction, or the optical axis direction.

[0189] According to an embodiment of the present invention, the first region 710R, the second region 720R, and the third region 730R are arranged within the region a defined by Equation 9.

[0190]

Equation

[0191] Here, a is the width of the region where the light intensity reaches 1 / e of the maximum light intensity, D means the distance from the light source 110 to the diffusion member 700, and θ can be defined as the angle at which the light intensity of 1 / e of the maximum light intensity of the light source 110 is output. 2 times the light intensity reaches, and D means the distance from the light source 110 to the diffusion member 700, and θ is 1 / e of the maximum light intensity of the light source 110 2 times the light intensity can be defined as the angle at which the light intensity is output.

[0192] In this regard, referring to FIG. 18, the light source 110 and the diffusion member 700 are arranged at a predetermined distance (D) from each other. Further, the light emitting element 112 outputs light at a predetermined angle (θ). When a virtual normal perpendicular to the substrate 111 is connected from the center of the light emitting element 112, the angle (θ / 2) formed by the virtual normal and the light is half of the divergence angle (θ) of the light output by the light emitting element 112. The plurality of light emitting elements 112 may all have the same standard, and the divergence angles (θ) at which the plurality of light emitting elements 112 output light may be the same as each other.

[0193] For example, the light emitting element 112 can emit a predetermined amount of energy from -20 degrees to 20 degrees with respect to the optical axis. However, it can be seen that at an angle of -15 degrees, or +15 degrees, or less than -15 degrees, or 15 degrees or more, the amount of energy is almost close to 0. That is, most of the energy exists within a predetermined angle with respect to the optical axis of the light emitting element. Therefore, it is inefficient to set all angles where the amount of energy is not 0 as the divergence angle of the light emitting element, and it is efficient to set the angle that diverges a certain amount or more of energy as the divergence angle of the light emitting element. Thereby, the divergence angle of the light source 110 can be set to the angle at which the light intensity is 1 / e 2 times the maximum light intensity of the light source 110, and the region a defined by Mathematical Formula 9 can be referred to as the effective light region.

[0194] At this time, the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3 may be different from each other. According to an embodiment of the present invention, the second average diameter AP2 may be larger than the first average diameter AP1, and the third average diameter AP3 may be larger than the second average diameter AP2. According to an embodiment of the present invention, the second average diameter AP2 may be 1.1 times or more the first average diameter AP1, and the third average diameter AP3 may be 1.1 times or more the second average diameter AP2. According to an embodiment of the present invention, the ratio of the second average diameter AP2 to the first average diameter AP1 may be larger than the ratio of the third average diameter AP3 to the second average diameter AP2. According to this, the energy of the output light can be dispersed to enhance the safety for the user's eyes, and a decrease in homogeneity due to interference can also be prevented.

[0195] As illustrated in FIG. 17, according to an embodiment of the present invention, a plurality of first microlenses 710 having a first average diameter AP1 within the first region 710R can have different diameters from each other. Here, the diameter may be a diameter in the first direction, a diameter in a second direction perpendicular to the first direction, or a diameter in a third direction which is the optical axis direction, and the first direction and the second direction may be directions perpendicular to the third direction. According to an embodiment of the present invention, the plurality of first microlenses 710 can have different diameters from each other within a range of 0.95 to 1.05 times, preferably 0.97 to 1.03 times, more preferably 0.98 to 1.02 times of the first average diameter AP1. According to this, it is possible to minimize the reinforcing interference and the canceling interference due to the overlap of the diffraction angles according to the diffraction orders of the plurality of first microlenses 710 within the first region 710R.

[0196] Similarly, a plurality of second microlenses 720 having a second average diameter AP2 within the second region 720R can have different diameters from each other. According to an embodiment of the present invention, the plurality of second microlenses 720 can have different diameters from each other within a range of 0.95 to 1.05 times, preferably 0.97 to 1.03 times, more preferably 0.98 to 1.02 times of the second average diameter AP2. According to this, it is possible to minimize the reinforcing interference and the canceling interference due to the overlap of the diffraction angles according to the diffraction orders of the plurality of second microlenses 720 within the second region 720R.

[0197] Similarly, a plurality of third microlenses 730 having a third average diameter AP3 within the third region 730R can have different diameters from each other. According to an embodiment of the present invention, the plurality of third microlenses 730 can have different diameters from each other within a range of 0.95 to 1.05 times, preferably 0.97 to 1.03 times, more preferably 0.98 to 1.02 times of the third average diameter AP3. According to this, it is possible to minimize the reinforcing interference and the canceling interference due to the overlap of the diffraction angles according to the diffraction orders of the plurality of third microlenses 730 within the third region 430R.

[0198] Therefore, the diameters of the plurality of first microlenses 710, the diameters of the plurality of second microlenses 720, and the diameters of the plurality of third microlenses 730 can each be designed by random number generation. When the diameters of the plurality of first microlenses 710 are designed by random number generation, the plurality of first microlenses 710 arranged in the first region 710R can have different diameters from each other. When the diameters of the plurality of second microlenses 720 are designed by random number generation, the plurality of second microlenses 720 arranged in the second region 720R can have different diameters from each other. When the diameters of the plurality of third microlenses 730 are generated by random number generation, the plurality of third microlenses 730 arranged in the third region 730R can have different diameters from each other. When the plurality of microlenses included in each region have different diameters from each other, the reinforcement interference and cancellation interference due to the overlap of the diffraction angles according to the diffraction order can be minimized.

[0199] According to an embodiment of the present invention, the random number generation for the diameter of the microlens can be designed using a Gaussian function distribution with a preset average diameter and standard deviation. According to an embodiment of the present invention, the diameters of the plurality of microlenses included in each region can be extracted by rejection sampling for the number of the plurality of microlenses included in each region.

[0200] Mathematical formula 10 shows a Gaussian function.

[0201]

Equation

[0202] Here, x is a variable, μ is an average, and σ is a standard deviation.

[0203] That is, when the average diameter and standard deviation for each region are defined, a Gaussian function distribution can be set. FIG. 19 shows a Gaussian function distribution set with an average diameter of 300 μm and a standard deviation of 2 μm.

[0204] On the one hand, it may be difficult to directly extract random numbers from a normal distribution as shown in FIG. 19. Therefore, in an embodiment of the present invention, rejection sampling can be used to extract random numbers for the diameters of a plurality of microlenses for each region.

[0205] For this purpose, an envelope function for the Gaussian function of Equation 10 is defined. The envelope function has a form similar to the Gaussian function of Equation 10, but has a value greater than the Gaussian function of Equation 10 for all values that the variable can have. Equation 11 is the envelope function for the Gaussian function of Equation 10.

[0206]

Equation

[0207] Here, x is a variable, μ is the mean, and σ is the standard deviation.

[0208] According to an embodiment of the present invention, random numbers are extracted from Equation 11 which is the envelope function. Equation 12 is a function for generating random numbers using a continuous uniform distribution from Equation 11 which is the envelope function.

[0209]

Equation

[0210] FIG. 20 is an example of a rejection sampling procedure according to an embodiment of the present invention. According to an embodiment of the present invention, the Gaussian function of Equation 10 and the envelope function of Equation 11 are compared using the random numbers extracted from Equation 12, and it can be determined whether to accept or reject the random numbers according to the comparison result. When the Gaussian function of Equation 10 and the envelope function of Equation 11 are compared, the difference is larger the farther away from the average value, and the difference is smaller the closer to the average value. Thus, it is advantageous to accept random numbers close to the average value.

[0211] Figure 21 shows the diffraction angles according to the diameter and the order of diffraction of the microlenses designed according to the embodiments of the present invention.

[0212] Referring to Figure 21, the diameters of the plurality of first microlenses 710 are set such that the first average diameter AP1 is 300 μm, the first standard deviation is 2.13, and the number of samples is 16, which is the result of designing by the random number generation method according to the embodiments of the present invention. From this, it can be seen that the diameters of the plurality of first microlenses 710 are all different from each other, and there is no overlapping portion in the diffraction angles of the diffraction discrimination.

[0213] The diameters of the plurality of second microlenses 720 are set such that the second average diameter AP2 is 400 μm, the second standard deviation is 3.42, and the number of samples is 16, which is the result of designing by the random number generation method according to the embodiments of the present invention. From this, it can be seen that the diameters of the plurality of second microlenses 720 are all different from each other, and there is no overlapping portion in the diffraction angles of the diffraction discrimination.

[0214] The diameters of the plurality of third microlenses 730 are set such that the third average diameter is 500 μm, the third standard deviation is 4.37, and the number of samples is 20, which is the result of designing by the random number generation method according to the embodiments of the present invention. From this, it can be seen that the diameters of the plurality of third microlenses 730 are all different from each other, and there is no overlapping portion in the diffraction angles of the diffraction discrimination.

[0215] Thus, since the diameters of the first to third microlenses 710 to 730 are all different, the diffraction angles according to the order of diffraction do not overlap, and the reinforcement interference and the cancellation interference due to the overlapping of the diffraction angles according to the order of diffraction can be minimized.

[0216] On the one hand, according to an embodiment of the present invention, the number and average diameter of the microlenses included in at least one of the first to third regions 710R, 720R, and 730R have a correlation with the average diameter of the microlenses included in another region surrounding at least one of the first to third regions 710R, 720R, and 730R. The number of microlenses for each region according to the embodiment of the present invention can be represented by Mathematical Formula 13.

[0217]

Number

[0218] Here, AP n is the average diameter of the microlenses arranged in the nth region, and AP n+1 is the average diameter of the microlenses arranged in the (n + 1)th region, and x n is the number of microlenses arranged along the first direction or the number of microlenses arranged along the second direction in the nth region. x n does not mean the number of all microlenses included in the nth region. For example, x1 may be 4 microlenses arranged along the first direction or the second direction in the first region, x2 may be 5 microlenses arranged along the first direction or the second direction in the second region, and x3 may be 6 microlenses arranged along the first direction or the second direction in the third region. Here, both sides of Mathematical Formula 13 can have a predetermined error range. For example, when the calculated values of the right side and the left side of Mathematical Formula 13 have an error range within ±3%, the equation of Mathematical Formula 13 can be analyzed as holding.

[0219] Accordingly, the number of microlenses included in the nth region can have a correlation with the average diameter of the microlenses included in the nth region and the average diameter of the microlenses included in the (n + 1)th region surrounding the nth region. The number and average diameter of the microlenses included in the nth region can have a correlation with the average diameter of the microlenses included in the (n + 1)th region surrounding the nth region.

[0220] For example, the number of the first microlenses 710 included in the first region 710R can have a correlation with the first average diameter AP1 of the first microlenses 710 included in the first region 710R and the second average diameter AP2 of the second microlenses 720 included in the second region 720R. The number of the first microlenses 710 and the first average diameter AP1 included in the first region 710R can have a correlation with the second average diameter AP2 of the second microlenses 720 included in the second region 720R. Also, the number of the second microlenses 720 included in the second region 720R can have a correlation with the second average diameter AP2 of the second microlenses 720 included in the second region 720R and the third average diameter AP3 of the third microlenses 730 included in the third region 730R. The number of the second microlenses 720 and the second average diameter AP2 included in the second region 720R can have a correlation with the third average diameter AP3 of the third microlenses 730 included in the third region 730R.

[0221] For example, the product of the first average diameter AP1 and the number of the first microlenses 710 arranged along the first direction may be the same as the product of a number that is 1 less than the number of the first microlenses 710 arranged along the first direction and the second average diameter AP2, and the product of the second average diameter AP2 and the number of the second microlenses 720 arranged along the first direction may be the same as the product of a number that is 1 less than the number of the second microlenses 720 arranged along the first direction and the third average diameter AP3. According to this, it is possible to minimize the reinforcing interference and the canceling interference due to the overlapping of the diffraction angles according to the diffraction orders for each region, and the arrangement of the microlens array is easy.

[0222] Table 4 shows an example of a microlens array according to an embodiment of the present invention under the condition that D>5.7 mm, which is the distance from the light source 110 to the diffusion member 700.

[0223]

Table 4

[0224] Here, n is the order of the region, the average diameter is the average diameter of the microlenses for each region, and the number is the number of microlenses repeatedly arranged along the first direction or the number of microlenses repeatedly arranged along the second direction.

[0225] For example, four microlenses with an average diameter of 300 μm in the first region can be arranged in a row along the first direction, five microlenses with an average diameter of 400 μm in the second region can be arranged in a row along the first direction, six microlenses with an average diameter of 500 μm in the third region can be arranged in a row along the first direction, seven microlenses with an average diameter of 600 μm in the fourth region can be arranged in a row along the first direction, eight microlenses with an average diameter of 700 μm in the fifth region can be arranged in a row along the first direction, and nine microlenses with an average diameter of 800 μm in the sixth region can be arranged in a row along the first direction.

[0226] Referring to Mathematical Formula 12, when n = 1, the average diameter is 300 μm, and when n = 2, the average diameter is 400 μm. In this case, the number of microlenses arranged in a row along the first direction when n = 1 can be 4. Similarly, when n = 2, the average diameter is 400 μm, and when n = 3, the average diameter is 500 μm. In this case, the number of microlenses arranged in a row along the first direction when n = 2 can be 5.

[0227] Also, when n = 6, the average diameter is 800 μm, and when n = 7, the average diameter is 900 μm. In this case, the number of microlenses arranged in a row along the first direction when n = 6 can be 9.

[0228] When arranging the microlens array under such conditions, it is possible to minimize the reinforcing interference and the canceling interference due to the overlap of the diffraction angles according to the diffraction orders for each region. Since three or more types of microlenses with different average diameters are arranged within the effective light region, it can be safer for the user's eyes.

[0229] Table 5 shows an example of a microlens array according to an embodiment of the present invention under the condition that D, which is the distance from the light source 110 to the diffusion member 700, is D>1.2 mm.

[0230] [Table 5]

[0231] Here, n is the order of the region, the average diameter is the average diameter of the microlenses for each region, and the number is the number of microlenses repeatedly arranged along the first direction or the number of microlenses repeatedly arranged along the second direction.

[0232] It can also be seen from Table 5 that it is designed to satisfy Equation 12. When arranging the microlens array under such conditions, it is possible to minimize the reinforcement interference and cancellation interference due to the overlap of diffraction angles according to the diffraction order for each region. Since three or more types of microlenses with different average diameters are arranged within the effective light region, it can be safer for the user's eyes.

[0233] Table 6 shows an example of a microlens array according to an embodiment of the present invention under the condition that D, which is the distance from the light source 110 to the diffusion member 700, is D>0.35 mm.

[0234] [Table 6]

[0235] Here, n is the order of the region, the average diameter is the average diameter of the microlenses for each region, and the number is the number of microlenses repeatedly arranged along the first direction or the number of microlenses repeatedly arranged along the second direction.

[0236] It can also be seen that in Table 6, it is designed to satisfy Mathematical Formula 12. When arranging the microlens array under such conditions, it is possible to minimize the reinforcing interference and the canceling interference due to the overlap of the diffraction angles according to the diffraction order for each region. Since three or more types of microlenses with different average diameters are arranged within the effective light region, it can be safer for the user's eyes.

[0237] Referring to Tables 4 to 6, it can be seen that the average diameter of the microlens changes depending on the distance D between the light source 110 and the diffusion member 700. Here, the distance D between the light source 110 and the diffusion member 700 may be the vertical distance between the first surface of the light source 110 and the first surface of the diffusion member 700. The first surface of the light source 110 means the surface where the light exit is arranged. The first surface of the diffusion member 700 means the surface where light from the light source 110 is input by each of the plurality of microlenses 710, 720, 730. Specifically, since a plurality of microlenses 710, 720, 730 are arranged in an embossing form on the first surface of the diffusion member 700, the first surface of the diffusion member 700 can be meant as the surface connecting the points through which the optical axes of the plurality of microlenses 710, 720, 730 pass. Therefore, the isolation distance between the diffusion member 700 and the light source 110 may be the vertical distance between the first surface of the light source 110 and a point through which the optical axes of the microlenses 710, 720, 730 pass.

[0238] As illustrated in Table 4, when D > 5.7 mm, it can be seen that the average diameter of the microlens is several hundred μm, for example, 300 μm or more, for example, 300 μm to 800 μm. As illustrated in Table 5, when D > 1.2 mm, it can be seen that the average diameter of the microlens is several tens of μm to several hundred μm, for example, 50 μm or more, for example, 50 μm to 120 μm. As illustrated in Table 6, when D > 0.35 mm, it can be seen that the average diameter of the microlens is several tens of μm, for example, 20 μm or more, for example, 20 μm to 70 μm. Thus, when the average diameter of the microlens changes depending on the distance D between the light source 110 and the diffusion member 700, the light flux concentration degree for a specific microlens can be reduced, so it can be safe for the user's eyes.

[0239] On the one hand, according to an embodiment of the present invention, a plurality of first microlenses 710 included in the first region 710R, a plurality of second microlenses 720 included in the second region 720R, and a plurality of third microlenses 730 included in the third region 730R can be protruded in the direction toward the light source 110. In the present specification, the direction from the diffusing member 700 toward the light source 110 can be referred to as a third direction perpendicular to the first direction and the second direction, which are the planar directions of the diffusing member 700. Here, the third direction may be the same as the optical axis direction of the first to third microlenses 710, 720, and 730.

[0240] At this time, the first average protrusion height (h1) of the plurality of first microlenses 710, the second average protrusion height (h2) of the plurality of second microlenses 720, and the third average protrusion height (h3) of the plurality of third microlenses 730 may be different from each other. Here, the first average protrusion height (h1), the second average protrusion height (h2), and the third average protrusion height (h3) can respectively mean the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3 in the third direction, which is the optical axis direction. According to this, since the boundaries of the first region 710R, the second region 720R, and the third region 730R are determined by the protrusion heights of the respective microlenses, the periodicity of the lattice is disrupted, and it is possible to minimize the reinforcing interference and the canceling interference due to the overlap of the diffraction angles according to the diffraction orders for each region. According to an embodiment of the present invention, the plurality of first microlenses 710 may all have different protrusion heights from each other, the plurality of second microlenses 720 may all have different protrusion heights from each other, and the plurality of third microlenses 730 may all have different protrusion heights from each other.

[0241] At this time, the plurality of first microlenses 710 included in the first region 710R, the plurality of second microlenses 720 included in the second region 720R, and the plurality of third microlenses 730 included in the third region 730R can each have an aspherical shape. For example, the aspherical shapes of the first microlens 710, the second microlens 720, and the third microlens 730 can be defined by the image height, the radius of curvature, and the conic constant. For example, the aspherical shapes of the first microlens 710, the second microlens 720, and the third microlens 730 can be defined by Equation 14.

[0242] [Number]

[0243] Here, Z is the aspherical shape of the lens, h is the image height, R is the radius of curvature, and K is the conic constant.

[0244] Since the microlens array is two-dimensionally arranged, the aspherical shapes of the first microlens 710, the second microlens 720, and the third microlens 730 can be defined by Equation 15.

[0245] [Number]

[0246] Here, x is the X-axis image height, y is the Y-axis image height, Rx is the X-axis radius of curvature, Ry is the Y-axis radius of curvature, Kx is the x-axis conic constant, and Ky is the Y-axis conic constant.

[0247] According to this, the FoI of the laser beam passing through the microlens array can be defined, and the light flux concentration degree of a specific microlens can be set so as not to exceed a predetermined value.

[0248] On the one hand, Fig. 22(a) is a plan view of a 3D drawing of a microlens array having a uniform diameter, and Fig. 22(b) is a perspective view of a 3D drawing of a microlens array having a uniform diameter. As described above, in the microlens array having a uniform diameter, the edge angles of the peripheral portion are sharply formed, and strong reinforcing interference due to diffraction occurs.

[0249] According to another embodiment of the present invention, the diffusing member includes a plurality of microlenses having different diameters from each other and different FoIs from each other. Hereinafter, for the sake of convenience of explanation, for the same content as that described through Figs. 1 to 21, duplicate explanations will be omitted.

[0250] Fig. 23(a) is a plan view of a 3D drawing of a microlens array according to another embodiment of the present invention, and Fig. 23(b) is a perspective view of a 3D drawing of a microlens array according to another embodiment of the present invention.

[0251] Referring to Figs. 23(a) and 23(b), a microlens array 1700 according to another embodiment of the present invention includes a plurality of microlenses 1701.

[0252] According to an embodiment of the present invention, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses 1701 have different diameters from each other. Here, the plurality of microlenses 1701 are two-dimensionally arranged along a first direction and a second direction perpendicular to the first direction. Here, the first direction can be referred to as the X direction, and the second direction can be referred to as the Y direction. Accordingly, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses 1701 can have different diameters from each other in the first direction. Or, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses 1701 can have different diameters from each other in the second direction.

[0253] According to an embodiment of the present invention, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses 1701 have different Fields of Illumination (FoI) from each other. Here, the FoI is defined by the aspherical shape, radius of curvature, and conic constant of each microlens. Accordingly, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses 1701 may have different aspherical shapes, radii of curvature, and conic constants from each other. Here, the plurality of microlenses are two-dimensionally arranged along a first direction and a second direction. Accordingly, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses may have different FoI in the first direction from each other. Or, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses may have different FoI in the second direction from each other. That is, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses may have at least one of different aspherical shapes, radii of curvature, and conic constants in the first direction from each other. Or, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses may have at least one of different aspherical shapes, radii of curvature, and conic constants in the second direction from each other.

[0254] Thus, when 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses have different diameters and / or different FoI from each other, the diffraction phenomenon due to interference is minimized, the homogeneity of the surface illumination pattern is increased, and it is safer for the user's eyes.

[0255] According to an embodiment of the present invention, the plurality of microlenses having different diameters and / or different FoI from each other are arranged within a region a defined by Mathematical Expression 16.

[0256]

Equation

[0257] Here, a is the width of the region where the light intensity reaches 1 / e of the maximum light intensity, D means the distance from the light source 110 to the diffusion member 1700, and θ can be defined as the angle at which the light intensity of 1 / e of the maximum light intensity of the light source 110 is output. 2 Here, a is the width of the region where the light intensity reaches 1 / e of the maximum light intensity, D means the distance from the light source 110 to the diffusion member 1700, and θ can be defined as the angle at which the light intensity of 1 / e of the maximum light intensity of the light source 110 is output. 2 can be defined.

[0258] In this regard, referring to FIG. 3, the light source 110 and the microlens array 120 are arranged at a predetermined distance (D) apart. Also, the light emitting element 112 outputs light at a predetermined angle (θ). When a virtual normal perpendicular to the substrate 111 is connected from the center of the light emitting element 112, the angle (θ / 2) formed by the virtual normal and the light is half of the divergence angle (θ) of the light output by the light emitting element 112. The plurality of light emitting elements 112 may all have the same standard, and the divergence angles (θ) at which the plurality of light emitting elements 112 output light may be the same as each other.

[0259] For example, the light emitting element 112 can emit a predetermined amount of energy from -20 degrees to 20 degrees with respect to the optical axis. However, it can be seen that the amount of energy is almost close to 0 at an angle of -15 degrees, or +15 degrees, or below -15 degrees, or 15 degrees or more. That is, most of the energy exists within a predetermined angle with respect to the optical axis of the light emitting element. Therefore, it is inefficient to set all the angles where the energy amount is not 0 as the divergence angle of the light emitting element, and it is efficient to set the angle at which a certain amount or more of energy is diverged as the divergence angle of the light emitting element. As a result, the divergence angle of the light source 110 can be set to the angle at which the light intensity of 1 / e of the maximum light intensity of the light source 110 is output, and the region a defined by Mathematical Formula 16 can be referred to as the effective light region. 2 can be set, and the region a defined by Mathematical Formula 16 can be referred to as the effective light region.

[0260] Here, the different diameters of the plurality of microlenses can be designed by random number generation. According to an embodiment of the present invention, the random number generation for the diameter of the microlens can be designed using a Gaussian function distribution with a preset average diameter and standard deviation. According to an embodiment of the present invention, the diameter of the microlens can be extracted by rejection sampling for only the number of microlenses.

[0261] Similarly, the different FoIs of the plurality of microlenses can be designed by random number generation. According to an embodiment of the present invention, the random number generation for the FoI of the microlens can be designed using a Gaussian function distribution with a preset average FoI and standard deviation. According to an embodiment of the present invention, the FoI of the microlens can be extracted by rejection sampling for only the number of microlenses.

[0262] Mathematical formula 17 shows a Gaussian function.

[0263]

Equation

[0264] Here, x is a variable, μ is an average, and σ is a standard deviation.

[0265] Figure 24(a) shows a Gaussian function distribution set with an average diameter of 300.2 μm in the X direction and a standard deviation of 10.94 μm, Figure 24(b) shows a Gaussian function distribution set with an average diameter of 301.2 μm in the Y direction and a standard deviation of 11.3 μm, Figure 25(a) shows a Gaussian function distribution set with an average FoI of 54.02 degrees in the X direction and a standard deviation of 0.9746 degrees, and Figure 25(b) shows a Gaussian function distribution set with an average FoI of 62.06 degrees in the Y direction and a standard deviation of 0.9323 degrees.

[0266] On the one hand, it may be difficult to directly extract random numbers from a normal distribution as shown in FIGS. 24(a) to 25(b). Therefore, in the embodiments of the present invention, rejection sampling can be used to extract random numbers for the diameters and / or FoIs of a plurality of microlenses.

[0267] For this purpose, an envelope function for the Gaussian function of Equation (17) is defined. The envelope function has a form similar to the Gaussian function of Equation (17), but has a value greater than the Gaussian function of Equation (17) for all values that the variable can have. Equation (18) is the envelope function for the Gaussian function of Equation (17).

[0268]

Equation

[0269] Here, x is a variable, μ is the mean, and σ is the standard deviation.

[0270] According to an embodiment of the present invention, random numbers are extracted from Equation (18), which is the envelope function. Equation (19) is a function for generating random numbers using a continuous uniform distribution from Equation (18), which is the envelope function.

[0271]

Equation

[0272] The rejection sampling procedure according to an embodiment of the present invention can be referred to FIG. 20. According to an embodiment of the present invention, the random numbers extracted from Equation (19) are used to compare the Gaussian function of Equation (17) and the envelope function of Equation (18), and it can be determined whether to accept or reject the random numbers according to the comparison result. When comparing the Gaussian function of Equation (17) and the envelope function of Equation (18), the difference is larger the farther away from the average value, and the difference is smaller the closer to the average value. Thus, it is advantageous to accept random numbers close to the average value.

[0273] On one hand, each microlens included in the plurality of microlenses can have an aspherical shape. The aspherical shape of each microlens can be defined by the image height, radius of curvature, and conic constant. For example, the aspherical shape of each microlens can be defined by Mathematical Formula 20.

[0274]

Number

[0275] Here, Z is the aspherical shape of the lens, h is the image height, R is the radius of curvature, and K is the conic constant.

[0276] Since the microlens array is arranged two-dimensionally, the aspherical shape of each microlens can be defined by Mathematical Formula 21.

[0277]

Number

[0278] Here, x is the X-axis image height, y is the Y-axis image height, Rx is the X-axis radius of curvature, Ry is the Y-axis radius of curvature, Kx is the x-axis conic constant, and Ky is the Y-axis conic constant.

[0279] The FoI of the laser beam passing through the microlens can be defined by the aspherical shape. Thus, in an embodiment of the present invention, in order to design a plurality of microlenses to have different FoIs from each other, at least one of the aspherical shape, the radius of curvature, and the conic constant of the microlens can be generated with random numbers. For example, the random numbers for at least one of the aspherical shape, the radius of curvature, and the conic constant of the microlens can be generated using a Gaussian function distribution with a preset average value and standard deviation, and can be extracted by rejection sampling for the number of microlenses. The random numbers for at least one of the aspherical shape, the radius of curvature, and the conic constant of the microlens can be designed by the rejection sampling described with reference to Mathematical Formulas 17 to 20 and FIG. 20.

[0280] Thus, in the microlens assembly 1700 according to an embodiment of the present invention, more than 50%, preferably more than 60%, more preferably more than 70% of the plurality of microlenses may have at least one of the aspherical shape, the radius of curvature, and the conic constant different from each other. Since the microlens assembly 1700 is arranged two-dimensionally, more than 50%, preferably more than 60%, more preferably more than 70% of the plurality of microlenses may have at least one of the aspherical shape, the radius of curvature, and the conic constant different from each other in the first direction, or at least one of the aspherical shape, the radius of curvature, and the conic constant different from each other in the second direction. At this time, at least a part of the plurality of microlenses having the same radius of curvature and conic constant in the first direction may have at least one of the radius of curvature and the conic constant different in the second direction, or at least a part of the plurality of microlenses having the same radius of curvature and conic constant in the second direction may have at least one of the radius of curvature and the conic constant different in the first direction.

[0281] FIG. 26 illustrates the diameter and FoI of the microlens designed according to an embodiment of the present invention, FIG. 27 illustrates the center positions of the microlens array according to the design of FIG. 26, FIG. 28(a) is an X-direction FoI graph according to the design of FIG. 26, FIG. 28(b) is a Y-direction FoI graph according to the design of FIG. 26, and FIG. 29 is a light-emitting image according to the design of FIG. 29.

[0282] Referring to FIG. 26, X pitch represents the diameter in the X direction, Y pitch represents the diameter in the Y direction, X_k represents the X-direction conic constant, X_R represents the X-direction radius of curvature, Y_k represents the Y-direction conic constant, Y_R represents the Y-direction radius of curvature, X FoI_simul. represents the FoI in the X direction, and Y FoI_simul. represents the FoI in the Y direction. The average diameter of a plurality of microlenses in the X direction is 300.2 μm with a standard deviation of 10.94 μm, the average diameter in the Y direction is 301.2 μm with a standard deviation of 11.3 μm, the average FoI in the X direction is 54.02 degrees with a standard deviation of 0.9746 degrees, the average FoI in the Y direction is 62.06 degrees with a standard deviation of 0.9323 degrees. The number of samples is set to 36, which is the result of designing by the random number generation method according to the embodiment of the present invention. From this, it can be seen that the diameters of the 36 microlenses are all different from each other, and the FoIs are also all different from each other.

[0283] Referring to FIG. 27, a uniform position within the 6*6 matrix grid means the center position of each grid, and a random position means the center positions of a plurality of microlenses generated according to the design of FIG. 26. According to this, it can be seen that the center positions of the plurality of microlenses generated according to the design of FIG. 26 are randomly arranged.

[0284] Referring to FIGS. 28(a) and 28(b), it can be seen that each microlens such as MLA7, MLA9, MLA29, and MLA31 has each FoI, but the Random MLA, which is the overall FoI of MLA1 to MLA36, converges to the pre-designed average FoI.

[0285] Referring to FIG. 29, it can be seen that the microlens array including MLA1 to MLA36 from the microlens array composed of 36 MLA7, the microlens array composed of 36 MLA9, the microlens array composed of 36 MLA29, and the microlens array composed of 36 MLA31 is effective in suppressing diffraction phenomenon and homogenizing the surface illumination pattern.

[0286] Also referring to FIGS. 23(a) and 23(b), the diffusing member 1700 according to an embodiment of the present invention includes a microlens array. The microlens array includes a plurality of microlenses, and 50% or more of the microlens array are microlenses having different FoIs from each other.

[0287] At this time, the microlens array includes a plurality of microlenses arranged in an N*M matrix. Here, N and M are each an integer of 3 or more, and may be the same as or different from each other. According to an embodiment of the present invention, a plurality of microlenses arranged in at least a 3*3 matrix have different FoIs from each other. As described above, since FoI is defined by an aspherical shape, a radius of curvature, and a conic constant, at least one of the aspherical shape, the radius of curvature, and the conic constant of a plurality of microlenses arranged in a 3*3 matrix may be different from each other.

[0288] According to an embodiment of the present invention, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses having different diameters and / or different FoIs from each other can be distributed dispersedly among other plurality of microlenses having the same diameter and / or the same FoI. Or, 50% or more, preferably 60% or more, more preferably 70% or more of the plurality of microlenses having different diameters and / or different FoIs from each other can be arranged adjacent to each other among other plurality of microlenses having the same diameter and / or the same FoI.

[0289] FIG. 30 is a plan view of a microlens array according to another embodiment of the present invention. For the sake of convenience of explanation, redundant explanations are omitted for the same content as that described with reference to FIGS. 1 to 29.

[0290] Referring to FIG. 30, a microlens array 1700 according to another embodiment of the present invention can be divided into a first region 1700R1 including the center of the microlens array 1700 and a second region 1700R2 surrounding the first region 1700R1 and including the edge of the microlens array 1700.

[0291] The first region 1700R1 includes a plurality of microlenses in at least a 3×3 matrix, and the plurality of microlenses included in the first region 1700R1 can have different FoIs from each other. At this time, the different FoIs of the plurality of microlenses included in the first region 1700R1 may be 0.9 to 1.1 times the average FoI. At this time, the different FoIs from each other can be designed by random number generation with reference to the descriptions of Mathematical Formulas 17 to 19 and FIG. 20. The plurality of microlenses included in the first region 1700R1 can have different FoIs from each other in the first direction or different FoIs from each other in the second direction. That is, the plurality of microlenses included in the first region 1700R1 can have at least one of different aspherical shapes, radii of curvature, and conic constants from each other in the first direction or at least one of different aspherical shapes, radii of curvature, and conic constants from each other in the second direction.

[0292] At this time, the area of the first region 1700R1 may be 50% to 70%, preferably 55% to 65% of the total area of the microlens array 1700. The first region 1700R1 is arranged within a region a defined with reference to the description of Mathematical Formula 16 and FIG. 3.

[0293] In addition, the second region 1700R2 includes a plurality of microlenses, and the plurality of microlenses included in the second region 1700R2 can have the same FoI.

[0294] According to this, the optical signal passing through the microlens array 1700 can be diffused and reach the target area including the object. According to this, the diffraction phenomenon due to interference can be reduced in the main part of the target area including the object, and an optical signal with a homogeneous surface pattern can reach, and the complexity of the design of the microlens array 1700 can be reduced.

[0295] Here, the plurality of microlenses included in the first region 1700R1 can have different diameters from each other. At this time, the different diameters of the plurality of microlenses included in the first region 1700R1 can be designed by random number generation with reference to the descriptions of Mathematical Formulas 17 to 19 and FIG. 20. According to this, the diffraction phenomenon due to interference can be reduced, and a homogeneous surface pattern can be realized.

[0296] FIG. 31 is a plan view of a microlens array according to still another embodiment of the present invention. For the sake of convenience of explanation, duplicate explanations are omitted for the same content as that described with reference to FIGS. 1 to 30.

[0297] Referring to FIG. 31, the microlens array 1700 according to still another embodiment of the present invention includes a first region 1700RA and a second region 1700RB disposed on the side surface of the first region 1700RA.

[0298] The first region 1700RA and the second region 1700RB each include a plurality of microlenses. The plurality of microlenses included in the first region 1700RA have different FoIs from each other, and the plurality of microlenses included in the second region 1700RB can have different FoIs from each other. At this time, the different FoIs from each other can be designed by random number generation with reference to the descriptions of Mathematical Formulas 17 to 19 and FIG. 20. The plurality of microlenses included in the first region 1700RA can have different FoIs from each other in the first direction or different FoIs from each other in the second direction. That is, the plurality of microlenses included in the first region 1700RA can have at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the first direction or at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the second direction. The plurality of microlenses included in the second region 1700RB can have different FoIs from each other in the first direction or different FoIs from each other in the second direction. That is, the plurality of microlenses included in the first region 1700RB can have at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the first direction or at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the second direction.

[0299] At this time, the average FoI of the plurality of microlenses included in the first region 1700RA and the average FoI of the plurality of microlenses included in the second region 1700RB may be the same. Here, the fact that the average FoIs are the same can include an error range within ±5%.

[0300] According to an embodiment of the present invention, the light source 110 may be a VCSEL, and the VCSEL can be driven in a split manner. For example, the light source 110 is divided into a first VCSEL region and a second VCSEL region, the first VCSEL region can be driven during a first time period, and the second VCSEL region can be driven during a second time period. The average FoI of the plurality of microlenses included in the first region 1700RA of the microlens array 1700 is the same as the average FoI of the plurality of microlenses included in the second region 1700RB, and the first region 1700RA of the microlens array 1700 is disposed at a position corresponding to the first VCSEL region, and the second region 1700RB of the microlens array 1700 can be disposed at a position corresponding to the second VCSEL region. According to this, during the entire time period, the diffraction phenomenon due to interference can be reduced, and a uniform surface pattern can be realized.

[0301] Here, the plurality of microlenses included in the first region 1700RA can have different diameters from each other. At this time, the different diameters of the plurality of microlenses included in the first region 1700RA can be designed by random number generation with reference to the descriptions of Mathematical Formulas 17 to 19 and FIG. 20. Also, the plurality of microlenses included in the second region 1700RB can have different diameters from each other. At this time, the different diameters of the plurality of microlenses included in the second region 1700RB can be designed by random number generation with reference to the descriptions of Mathematical Formulas 17 to 19 and FIG. 20. According to this, the diffraction phenomenon due to interference can be reduced, and a uniform surface pattern can be realized.

[0302] According to still another embodiment of the present invention, the microlens array is divided into a plurality of regions and can include microlenses having different average diameters for each region.

[0303] FIG. 32 is a plan view of a microlens array according to another embodiment of the present invention, FIG. 33 is a drawing for explaining the diameter of a microlens forming the microlens array according to another embodiment of the present invention, and FIG. 34 is an example of the first region 1710R of FIG. 32.

[0304] Referring to FIGS. 32 to 34, a microlens array 1700 according to another embodiment of the present invention includes a first region 1710R including a plurality of first microlenses 1710 having a first average diameter AP1, a second region 1720R surrounding the first region 1710R and including a plurality of second microlenses 1720 having a second average diameter AP2, and a third region 1730R surrounding the second region 1720R and including a plurality of third microlenses 1730 having a third average diameter AP3. Here, for the same content as that described with reference to FIGS. 1 to 31 in the description of the microlens array 1700, duplicate descriptions are omitted. Here, the description is centered on the first to third regions 1710R to 1730R including the first to third microlenses having the first to third average diameters, but this is for convenience of explanation and is not limited thereto. An embodiment of the present invention may be a microlens array including only the first region 1710R and the second region 1720R, and may be extended to a fourth region surrounding the third region 1730R and including a plurality of fourth microlenses having a fourth average diameter, a fifth region surrounding the fourth region and including a plurality of fifth microlenses having a fifth average diameter, and the like.

[0305] Here, the first region 1710R may be a region including the center of the microlens array 1700.

[0306] According to an embodiment of the present invention, the first region 1710R includes a plurality of first microlenses 1710 arranged along a first direction, the second region 1720R includes a plurality of second microlenses 1720 arranged along the first direction, and the third region 1730R includes a plurality of third microlenses 1730 arranged along the first direction.

[0307] Further, a plurality of first microlenses 1710 are arranged along a second direction that is perpendicular to the first direction and intersects the optical axis direction in the first region 1710R, a plurality of second microlenses 1720 are arranged along the second direction in the second region 1720R, and a plurality of third microlenses 1730 are arranged along the second direction in the third region 1730R.

[0308] At this time, the plurality of first microlenses 1710 arranged in the outermost row and outermost column of the first region 1710R can be arranged adjacent to the plurality of second microlenses 1720 arranged in the second region 1720R, and the plurality of second microlenses 1720 arranged in the second region 1720R can be arranged adjacent to the plurality of third microlenses 1730 arranged in the third region 1730R. The plurality of second microlenses 1720 can be arranged in a row so as to surround the outermost contour of the first region 1710R, and the plurality of third microlenses 1730 can be arranged in a row so as to surround the second region 1720R. Thereby, on one side surface of each second microlens 1720 in a direction perpendicular to the direction in which the plurality of second microlenses 1720 are arranged, the first microlenses 1710 can be arranged, and on the other side surface, the third microlenses 1730 can be arranged. That is, on both side surfaces of each second microlens 1720 in a direction perpendicular to the direction in which the plurality of second microlenses 1720 are arranged, the second microlenses 1720 do not necessarily need to be arranged. Similarly, on both side surfaces of each third microlens 1730 in a direction perpendicular to the direction in which the plurality of third microlenses 1730 are arranged, the third microlenses 1730 do not necessarily need to be arranged. The distance from the center of the diffusing member 1700, that is, the microlens array, to the second microlens 1720 may be greater than the distance from the center of the microlens array to the first microlens 1710, and the distance from the center of the microlens array to the third microlens 1730 may be greater than the distance from the center of the microlens array to the second microlens 1720.

[0309] Here, the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3 can be used interchangeably with the first average pitch AP1, the second average pitch AP2, and the third average pitch AP3, respectively. Here, the diameter can mean the length of the microlens in the first direction or the second direction. However, the diameter can also mean the length of the microlens in a direction other than the first and second directions. For example, the diameter can also mean the length of the microlens in the third direction, which is the first direction, the second direction, or the optical axis direction.

[0310] At this time, the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3 may be different from each other. According to an embodiment of the present invention, the second average diameter AP2 may be larger than the first average diameter AP1, and the third average diameter AP3 may be larger than the second average diameter AP2. According to an embodiment of the present invention, the second average diameter AP2 may be 1.1 times or more the first average diameter AP1, and the third average diameter AP3 may be 1.1 times or more the second average diameter AP2. According to an embodiment of the present invention, the ratio of the second average diameter AP2 to the first average diameter AP1 may be larger than the ratio of the third average diameter AP3 to the second average diameter AP2. According to this, the energy of the output light can be dispersed to enhance the safety for the user's eyes, and a decrease in homogeneity due to interference can also be prevented.

[0311] According to an embodiment of the present invention, the plurality of first microlenses 1710 in the first region 1710R can have different FoIs from each other, the plurality of second microlenses 1720 in the second region 1720R can have different FoIs from each other, and the plurality of third microlenses 1730 in the third region 1730R can have different FoIs from each other. That is, the plurality of first microlenses 1710 in the first region 1710R can have at least one of different aspherical shapes, radii of curvature, and conic constants from each other, the plurality of second microlenses 1720 in the second region 1720R can have at least one of different aspherical shapes, radii of curvature, and conic constants from each other, and the plurality of third microlenses 1730 in the third region 1730R can have at least one of different aspherical shapes, radii of curvature, and conic constants from each other.

[0312] As described above, the FoIs different from each other for each region can be designed by random number generation described with reference to Mathematical Formulas 17 to 19 and FIG. 20.

[0313] At this time, the plurality of first microlenses 1710 in the first region 1710R can have different FoIs from each other in the first direction, the plurality of second microlenses 1720 in the second region 1720R can have different FoIs from each other in the first direction, and the plurality of third microlenses 1730 in the third region 1730R can have different FoIs from each other in the first direction. Or, the plurality of first microlenses 1710 in the first region 1710R can have different FoIs from each other in the second direction, the plurality of second microlenses 1720 in the second region 1720R can have different FoIs from each other in the second direction, and the plurality of third microlenses 1730 in the third region 1730R can have different FoIs from each other in the second direction. That is, the plurality of first microlenses 1710 in the first region 1710R can have at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the first direction, the plurality of second microlenses 1720 in the second region 1720R can have at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the first direction, and the plurality of third microlenses 1730 in the third region 1730R can have at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the first direction. Or, the plurality of first microlenses 1710 in the first region 1710R can have at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the second direction, the plurality of second microlenses 1720 in the second region 1720R can have at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the second direction, and the plurality of third microlenses 1730 in the third region 1730R can have at least one of aspherical shapes, radii of curvature, and conic constants that are different from each other in the second direction.

[0314] At this time, the average FoI of the first region 1710R, the average FoI of the second region 1720R, and the average FoI of the third region 1730R may be the same as each other. Here, the average FoI that is the same as each other can include an error range within ±5%. According to this, even if each microlens included in the microlens array 1700 has a different FoI from each other, the surface illumination pattern output by the microlens array 1700 converges to the average FoI, and thus a uniform surface illumination pattern can be obtained.

[0315] According to an embodiment of the present invention, the plurality of first microlenses 1710 having the first average diameter AP1 in the first region 1710R can have different diameters from each other. The plurality of second microlenses 1720 having the second average diameter AP2 in the second region 1720R can have different diameters from each other. The plurality of third microlenses 1730 having the third average diameter AP3 in the third region 1730R can have different diameters from each other.

[0316] Therefore, the diameters of the plurality of first microlenses 1710, the diameters of the plurality of second microlenses 1720, and the diameters of the plurality of third microlenses 1730 can each be designed by random number generation. When the plurality of microlenses included in each region have different diameters from each other, the reinforcing interference and the canceling interference due to the overlapping of the diffraction angles according to the diffraction order can be minimized. The random number generation for the diameter of the microlens can refer to Mathematical Formulas 17 to 19 and FIG. 20.

[0317] On the other hand, according to an embodiment of the present invention, the number and the average diameter of the microlenses included in at least one of the first to third regions 1710R, 1720R, 1730R are correlated with the average diameter of the microlenses included in another region surrounding at least one of the first to third regions 1710R, 1720R, 1730R. The number of microlenses for each region according to the embodiment of the present invention can refer to Mathematical Formula 13.

[0318] According to an embodiment of the present invention, the average diameter of the microlenses can be changed by the distance D between the light source 110 and the microlens array 1700. For example, as the distance D between the light source 110 and the microlens array 1700 increases, the average diameter of the microlenses can become larger. According to this, the light flux concentration degree for a specific microlens can be decreased, so it can be safe for the user's eyes.

[0319] FIG. 35 is an exploded view of a camera module according to an embodiment of the present invention.

[0320] The camera module may include a light emitting part and a light receiving part. However, since components such as the substrate 10, the holder 30, and the shield can 50 are integrally formed and commonly used for the light emitting part and the light receiving part, it may be difficult to distinguish them into the light emitting part and the light receiving part. In this case, each of the above components can be understood as a component of each of the light emitting part and the light receiving part. However, as a modification, the common components such as the substrate 10, the holder 30, and the shield can 50 can be separately provided for the light emitting part and the light receiving part, respectively.

[0321] The light emitting part may include the substrate 10, the light source 20, the holder 30, the diffusing member 41, the diffuser ring 42, and the shield can 50. The light receiving part may include the substrate 10, the sensor 60, the filter 80, the holder 30, the lens 70, the barrel 71, and the shield can 50.

[0322] The substrate 10 can include a printed circuit board (PCB). The substrate 10 can be connected to a connector through the FPCB91. The substrate 10 and the FPCB91 can be formed of a rigid flexible PCB (RFPCB). A light source 20 and a sensor 60 can be arranged on the substrate 10. The substrate 10 can be arranged under the holder 30. The substrate 10 can include terminals. The terminals of the substrate 10 can be connected to the coupling part of the shield can 50. The terminals of the substrate 10 can include a plurality of terminals. The terminals of the substrate 10 can include two terminals.

[0323] The light source 20 can be arranged on the substrate 10. The light source 20 can be arranged in contact with the substrate 10. The light source 20 can be arranged on the substrate 10. The light source 20 can be arranged on the substrate 10. The light source 20 can correspond to the light source 110 described above.

[0324] The holder 30 can be arranged on the substrate 10. The holder 30 can be arranged in contact with the substrate 10. The holder 30 can be arranged on the substrate 10. The holder 30 can be arranged on the substrate 10. The holder 30 can be fixed to the substrate 10 by an adhesive. The holder 30 can accommodate the light source 20, the diffuser module 40, the sensor 60, and the filter 80 inside. The holder 30 may be a plastic injection molding. The holder 30 can be formed by injection.

[0325] The diffuser module 40 can include a diffusing member 41 and a diffuser ring 42. The diffuser module 40 can be integrally formed as in a modified example, but in this embodiment, in order to increase the moldability during injection molding, the diffusing member 41 and the diffuser ring 42 can be separately manufactured. The diffusing member 41 and the diffuser ring 42 can be separated from each other.

[0326] The diffusion member 41 may be a diffuser lens. The diffusion member 41 can correspond to the diffusion members 120 and 400 described above. The diffusion member 41 can be disposed within the holder 30. The diffusion member 41 can be coupled to the holder 30. The diffusion member 41 can be fixed to the holder 30. The diffusion member 41 can be disposed on the optical path of the light emitted from the light source 20. The diffusion member 41 can be disposed on the light source 20. The diffusion member 41 can be disposed on the light source 20. The diffusion member 41 may be a plastic injection molding. The diffusion member 41 can be formed by plastic injection. The height of the upper end of the diffusion member 41 can correspond to the height of the upper end of the lens 70. The diffusion member 41 can be inserted upward in the vertical direction and coupled to the holder 30. At this time, the upward direction may be the direction from the lower part of the holder 30 to the upper part of the holder 30. A part of the diffusion member 41 can be overlapped with the holder 30 upward.

[0327] The diffuser ring 42 can be disposed within the holder 30. The diffuser ring 42 can be fixed to the holder 30. The diffuser ring 42 can be coupled to the holder 30. The diffuser ring 42 can be disposed under the diffusion member 41. The diffuser ring 42 can support the diffusion member 41. The diffuser ring 42 can be brought into contact with the diffusion member 41. The diffuser ring 42 may be a plastic injection molding. The diffuser ring 42 can be formed by plastic injection.

[0328] The shield can 50 can cover the main body of the holder 30. The shield can 50 can include a cover. The shield can 50 can include a cover can. The shield can 50 may be a non-magnetic body. The shield can 50 can be formed of a metal material. The shield can 50 can be formed of a metal plate material. The shield can 50 can be electrically connected to the substrate 10. The shield can 50 can be connected to the substrate 10 through solder balls. Through this, the shield can 50 can be grounded. The shield can 50 can block electromagnetic interference noise (EMI). At this time, the shield can 500 can be called an "EMI shield can". In this embodiment, since a high voltage is used inside the optical device, electromagnetic interference noise may increase, but the shield can 50 can block the electromagnetic interference noise.

[0329] The sensor 60 can be disposed on the substrate 10. The sensor 60 can be disposed on the other side of the partition wall of the holder 30 on the substrate 10. That is, the sensor 60 can be disposed on the opposite side of the light source 20 with respect to the partition wall of the holder 30. The sensor 60 can sense infrared rays. The sensor 60 can sense light of a specific wavelength among infrared rays. The sensor 60 can sense the light that has passed through the filter 80. The sensor 60 can sense the light in the wavelength band of the light source 20. Through this, the sensor 60 can sense the light emitted from the light source 20 and reflected by the subject, and sense the 3D image information of the subject. The effective sensing area of the sensor 60 is disposed corresponding to the diffusion member 41, but the sensor 60 can be disposed biased in the overall partition wall direction. The circuit pattern of the sensor 60 and the like can be disposed in the portion of the sensor 60 biased in the partition wall direction.

[0330] The lens 70 can be fixed within the barrel 71. The lens 70 may be a plastic injection molding. The lens 70 can be formed by plastic injection. The lens 70 can include a plurality of lenses.

[0331] The filter 80 can be disposed between the lens 70 and the sensor 60. The filter 80 may be a band pass filter that allows light in a specific wavelength band to pass through. The filter 80 can allow infrared light to pass through. The filter 80 can allow light of a specific wavelength among infrared light to pass through. The filter 80 can allow light in the wavelength band of the light emitted by the light source 20 to pass through. The filter 80 can block visible light. The filter 80 can be coupled to the holder 30. A groove sized to correspond to the filter 80 is formed in the holder 30, and the filter 80 can be inserted into the groove and fixed with an adhesive. Adhesive injection grooves for injecting an adhesive between the filter 80 and the holder 30 can be formed together in the groove of the holder 30. The filter 80 can be disposed at a position lower than the position of the diffuser ring 42.

[0332] As described above, the description has centered on the camera device that extracts depth information using the ToF method, but the embodiments of the present invention are not limited thereto. The camera device according to the embodiments of the present invention can also mean a camera device that extracts depth information using the structured light method. That is, the camera device according to the embodiments of the present invention can use structured light having a predetermined pattern as an output optical signal and generate depth information using the disparity of the structured light. Further, the camera device according to the embodiments of the present invention can also mean a camera device mounted on an automobile for measuring the distance between the automobile and an object. That is, the camera device according to the embodiments of the present invention may be a LIDAR (Light Detection and Ranging) camera.

[0333] Although the above has been described mainly with reference to the embodiments, these are merely examples and do not limit the present invention. Those having ordinary knowledge in the field to which the present invention pertains will understand that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments can be implemented with modifications. Also, differences regarding such modifications and applications should be construed as being included in the scope of the present invention defined by the appended claims.

Claims

1. A light emitting unit that irradiates an object with an optical signal, A light receiving unit including an image sensor that receives the optical signal reflected from the object, A depth information generation unit that generates depth information of the object using the optical signal received by the light receiving unit, The light emitting unit includes A light source, A microlens array disposed on the light source, The microlens array includes A first region including a plurality of first microlenses having a first diameter, A second region surrounding the first region and including a plurality of second microlenses having a second diameter, A third region surrounding the second region and including a plurality of third microlenses having a third diameter, A camera device, wherein the number and diameter of the microlenses included in at least one of the first to third regions have a correlation with the diameter of the microlenses included in another region surrounding at least one of the first to third regions.

2. The camera device according to claim 1, wherein the first diameter, the second diameter, and the third diameter are different from each other.

3. The first region includes x1 first microlenses arranged along a first direction, The second region includes x2 second microlenses arranged along the first direction, The third region includes x3 third microlenses arranged along the first direction, The product of the first diameter and x1 is the same as the product of the second diameter and a number one less than x1, The camera device according to claim 2, wherein the product of the second diameter and x2 is the same as the product of the third diameter and a number one less than x2.

4. In the first region, x1 first microlenses are arranged along a second direction perpendicular to the first direction, In the second region, x2 second microlenses are arranged along the second direction, The camera device according to claim 3, wherein in the third region, x3 third microlenses are arranged along the second direction.

5. The plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses protrude in a direction toward the light source, The camera device according to claim 1, wherein the protruding heights of the plurality of first microlenses, the protruding heights of the plurality of second microlenses, and the protruding height of the third microlenses are different from each other.

6. Each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses has an aspherical shape, The aspherical shape of each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses is defined by an image height, a radius of curvature, and a conic constant, the camera device according to claim 1.

7. The aspherical shape of each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses is defined by the following mathematical formula, the camera device according to claim 6: 【Number 1】 Here, x is the X-axis image height, y is the Y-axis image height, R ｘ is the X-axis curvature radius, R ｙ is the Y-axis curvature radius, K ｘ is the x-axis conic constant, K ｙ is the Y-axis conic constant.

8. The number and diameter of the first microlenses included in the first region have a correlation with the diameter of the second microlenses included in the second region, the camera device according to claim 1.

9. The distance from the center of the microlens array to the second microlens is greater than the distance from the center of the microlens array to the first microlens, the camera device according to claim 1.

10. The first diameter, the second diameter, and the third diameter vary depending on the distance between the light source and the microlens array, the camera device according to claim 1.

Images