Camera device

Abstract

A camera device according to an embodiment of the present invention comprises: a light emitting unit for irradiating a light signal to an object; a light receiving unit including an image sensor and receiving a light signal reflected from the object; and a depth information generating unit for generating depth information of the object by using the light signal received by the light receiving unit, the light emitting unit including 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 are related to the diameter of the microlenses included in another region surrounding the at least one of the first to third regions.

Description

Technical Field

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

[0002] Three-dimensional content is used in many fields such as gaming, culture, education, manufacturing, and autonomous driving, and depth information (depth map) is required to obtain three-dimensional content. Depth information is information indicating spatial distance, and indicates perspective information of one point relative to another point in a two-dimensional image. A method of projecting infrared (IR) structured light onto an object, a method using a stereo camera, a time-of-flight (TOF) method, and the like are used as methods for obtaining depth information.

[0003] According to the TOF method, the distance to an object is calculated by measuring TOF (i.e., the reflection time of the photographed light). The greatest advantage of the TOF method is that it provides distance information about a three-dimensional space quickly and in real time. In addition, the user can obtain accurate distance information without adopting a separate algorithm or performing hardware calibration. In addition, by measuring very close objects or moving objects, accurate depth information can be obtained.

[0004] At the same time, in order to obtain depth information, the light emitting unit of the camera device generates an output light signal and irradiates the output light signal to the object, the light receiving unit of the camera device receives an input light signal reflected from the object, and the depth information generating unit of the camera device uses the input light signal received by the light receiving unit to generate depth information of the object.

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

[0006] The uniformity of the surface illumination pattern may vary due to the design of the MLA, and the safety of the user's eyes may also vary. Therefore, the design of the MLA is very important. Summary of the invention

[0007]

Technical issues

[0008] The present invention is directed to providing a camera device capable of extracting depth information with high accuracy and high resolution.

[0009] The present invention also aims to provide a camera device including a light emitting unit having a highly uniform surface illumination pattern and excellent user eye safety.

[0010]

Technical solution

[0011] A camera device according to an embodiment of the present invention includes: a light emitting unit configured to irradiate a light signal to an object; a light receiving unit including an image sensor and configured to receive a light signal reflected from the object; and a depth information generating unit configured to generate depth information of the object using the light signal received by the light receiving unit, wherein the light emitting unit includes a light source and a microlens array arranged on the light source, the microlens array including: a first area including a plurality of first microlenses having a first diameter; a second area surrounding the first area and including a plurality of second microlenses having a second diameter; and a third area surrounding the second area and including a plurality of third microlenses having a third diameter, and the number and diameter of the microlenses included in at least one area among the first area to the third area have a correlation with the diameter of the microlenses included in another area surrounding at least one area among the first area to the third area.

[0012] The first diameter, the second diameter, and the third diameter may be different.

[0013] The first area may include x1 first microlenses arranged along the first direction, the second area may include x2 second microlenses arranged along the first direction, the third area may include 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 less than x1 by 1, and the product of the second diameter and x2 may be the same as the product of the third diameter and a number less than x2 by 1.

[0014] x1 first microlenses may be arranged in a second direction perpendicular to the first direction in the first region, x2 second microlenses may be arranged in the second direction in the second region, and x3 third microlenses may be arranged in the second direction in the third region.

[0015] The plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses may protrude in a direction toward the light source, and protrusion heights of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses may be different.

[0016] Each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses may have an aspherical surface.

[0017] The aspherical shape of each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses may be defined by an image height, a radius of curvature, and a cone constant.

[0018] The aspherical shape of each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses may be defined by the following Mathematical Formula 1:

[0019]

[0020] Where x represents the image height on the X axis, y represents the image height on the Y axis, and R x Indicates the X-axis curvature radius, R y Indicates the Y-axis curvature radius, K x represents the X-axis cone constant, K y Represents the Y-axis cone constant.

[0021] The number and diameter of the first microlenses included in the first region may have a correlated relationship with the diameter of the second microlenses included in the second region.

[0022] A distance between a center of the microlens array and the second microlens may be greater than a distance from the center of the microlens array to the first microlens.

[0023] The first diameter, the second diameter, and the third diameter may vary according to the distance between the light source and the microlens array.

[0024] A camera device according to another embodiment of the present invention includes: a light-emitting unit configured to irradiate a light signal to an object; a light-receiving unit including an image sensor and configured to receive a light signal reflected from the object; and a depth information generating unit configured to generate depth information of the object using the light signal received by the light-receiving unit, wherein the light-emitting unit includes a light source and a microlens array arranged on the light source, the microlens array including: a first area including a plurality of first microlenses having a first average diameter; and a second area surrounding the first area 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 being different, and the diameters of the plurality of second microlenses being different.

[0025] The diameters of the plurality of first microlenses may be included in a range of 0.95 times 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 times to 1.05 times the second average diameter.

[0026] The second average diameter may be greater than the first average diameter.

[0027] The second average diameter may be 1.1 times or more the first average diameter.

[0028] The diameters of the plurality of first microlenses and the diameters of the plurality of second microlenses may be designed by random number generation, respectively.

[0029] The diameters of the plurality of first microlenses can be designed by random number generation using a Gaussian function distribution according to a 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 according to a second average diameter and a second standard deviation different from the first standard deviation.

[0030] The diameters of the plurality of first microlenses and the diameters of the plurality of second microlenses may be extracted by rejection sampling the same number of times as the number of the plurality of first microlenses and the number of the plurality of second microlenses, respectively.

[0031] The camera device may also include a third area, which includes a plurality of third microlenses, which surround the second area and have a third average diameter different from the first average diameter and the second average diameter, wherein the number and average diameter of the microlenses included in at least one area of ​​the first to third areas may have a correlation with the average diameter of the microlenses included in another area surrounding at least one area of ​​the first to third areas.

[0032] The first region may include x1 first microlenses arranged along the first direction, the second region may include x2 second microlenses arranged along the first direction, the third region may include x3 third microlenses arranged along the first direction, the product of the first average diameter and x1 may be the same as the product of the second average diameter and a number less than x1 by 1, 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 less than x2 by 1.

[0033] x1 first microlenses may be arranged in a second direction perpendicular to the first direction in the first region, x2 second microlenses may be arranged in the second direction in the second region, and x3 third microlenses may be arranged in the second direction in the third region.

[0034] The first average diameter and the second average diameter may be average diameters according to a first direction perpendicular to the optical axis direction, a second direction perpendicular to the optical axis direction and the first direction, or the optical axis direction, respectively.

[0035] According to one embodiment of the present invention, a light output device includes a light source and a microlens array arranged on the light source, wherein the microlens array includes: a first area, including a plurality of first microlenses having a first average diameter; and a second area, surrounding the first area and including a plurality of second microlenses having a second average diameter different from the first average diameter, wherein the diameters of the plurality of first microlenses are different, and the diameters of the plurality of second microlenses are different.

[0036] According to another embodiment of the present invention, a camera device includes: a light-emitting unit configured to irradiate a first light signal to an object; a light-receiving unit configured to receive a second light signal reflected from the object; and a depth information generating unit configured to generate depth information of the object using the second light signal, wherein the light-emitting unit includes a light source and a microlens array arranged 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 illumination fields (FoI).

[0037] 50% or more of the microlens array may be microlenses with different FoIs.

[0038] At least one of an aspherical shape, a radius of curvature, and a cone constant of each of the plurality of micro lenses arranged in a 3*3 matrix may be different.

[0039] A plurality of microlenses arranged in a 3*3 matrix may be arranged in a first area including the center of the microlens array, the microlens array may further include a plurality of microlenses arranged in a second area surrounding the first area, and at least one of the aspherical shape, the radius of curvature and the cone constant of each of the plurality of microlenses arranged in the first area may be different.

[0040] At least one of an aspherical shape, a radius of curvature, and a cone constant of each of the plurality of microlenses disposed in the second region may be different.

[0041] The plurality of microlenses disposed in the first region may have a first average diameter, the plurality of microlenses arranged in the second region may have a second average diameter different from the first average diameter, the plurality of microlenses disposed in the first region may have different diameters, and the plurality of microlenses disposed in the second region may have different diameters.

[0042] According to another embodiment of the present invention, a camera device includes: a light-emitting unit configured to irradiate a first light signal to an object; a light-receiving unit configured to receive a second light signal reflected from the object; and a depth information generating unit configured to generate depth information of the object using the second light signal, wherein the light-emitting unit includes a light source and a microlens array arranged on the light source, the microlens array includes a first microlens and a plurality of second microlenses surrounding and closest to the first microlens, the plurality of second microlenses have different FoIs, and the first microlens and the plurality of second microlenses have different FoIs.

[0043] At least one of an aspherical shape, a radius of curvature, and a cone constant of each of the plurality of second microlenses may be different.

[0044] At least one of an aspherical shape, a radius of curvature, and a cone constant of each of the first microlens and the plurality of second microlenses may be different.

[0045] According to another embodiment of the present invention, a camera device includes: a light-emitting unit configured to irradiate a first light signal to an object; a light-receiving unit configured to receive a second light signal reflected from the object; and a depth information generating unit configured to generate depth information of the object using the second light signal, wherein the light-emitting unit includes a light source and a microlens array arranged on the light source, the microlens array includes a plurality of microlenses, 50% or more of the plurality of microlenses have different FoIs in a first direction, or 50% or more of the plurality of microlenses have different FoIs in a second direction perpendicular to the first direction.

[0046] At least one of the aspherical shape, the radius of curvature, and the conic constant of each of 50% or more of the microlenses in the plurality of microlenses may be different.

[0047] The microlens array may include: a first area, including a plurality of first microlenses having a first average diameter; a second area, including a plurality of second microlenses surrounding the first area and having a second average diameter different from the first average diameter, wherein the diameters of the plurality of first microlenses may be different, the diameters of the plurality of second microlenses may be different, and the plurality of first microlenses and the plurality of second microlenses may have different FoIs.

[0048] The plurality of microlenses may include: 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 located on the circumference of the first region and including the edge, and at least one of the aspherical shape, the radius of curvature, and the cone constant of each lens of the first microlens group may be different.

[0049] At least one of the aspherical shape, the curvature radius, and the cone constant of each lens of the second microlens group may be different.

[0050] At least one of the radius of curvature and the cone constant of each of at least some of the multiple microlenses having the same radius of curvature and the cone constant in the first direction may be different in the second direction, or at least one of the radius of curvature and the cone constant of each of at least some of the multiple microlenses having the same radius of curvature and the cone constant in the second direction may be different in the first direction.

[0051] According to another embodiment of the present invention, a light output device includes a light source and a microlens array arranged on the light source, wherein the microlens array includes a first microlens and a plurality of second microlenses surrounding and closest to the first microlens, the FoIs of the first microlens and the plurality of second microlenses are different, and the FoIs of the plurality of second microlenses are different.

[0052]

Beneficial Effects

[0053] According to the embodiments of the present invention, a camera device capable of ensuring a highly uniform surface illumination pattern and safety of the user's eyes and capable of extracting depth information with high accuracy and high resolution can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a block diagram of a camera apparatus according to an embodiment of the present invention.

[0055] Figure 2 is a view for describing an output light signal output by a camera apparatus according to an embodiment of the present invention.

[0056] Figure 3 is a schematic diagram of a light emitting unit according to an embodiment of the present invention.

[0057] Figure 4 is a plan view of a diffusion member according to an embodiment of the present invention.

[0058] Figure 5 and Figure 6 : is a view for describing the diameter of a microlens forming a diffusion member according to one embodiment of the present invention.

[0059] Figure 7 is a cross-sectional view of a diffusion member and a light source according to one embodiment of the present invention.

[0060] Figure 8 (a) is a plan view of a three-dimensional image of a microlens array according to a comparative example, Figure 8 (b) is a stereogram of a three-dimensional image of a microlens array according to a comparative example.

[0061] Fig. 9 The results of a Monte Carlo ray tracing simulation of a microlens array according to a comparative example are shown.

[0062] Fig.10 (a) shows the result of FDTD simulation of the microlens array according to the comparative example, Fig.10 (b) is Fig.10 Magnified images of some areas in (a).

[0063] Fig.11 (a) is a plan view of a three-dimensional image of a microlens array according to an embodiment, Fig.11 (b) is a perspective view of a three-dimensional image of a microlens array according to an embodiment.

[0064] Fig.12 Results of a Monte Carlo ray tracing simulation of a microlens array according to an embodiment are shown.

[0065] Fig.13 (a) shows the result of FDTD simulation of the microlens array according to the embodiment, Fig.13 (b) is Fig.13 Magnified images of some areas in (a).

[0066] Fig.14 is a plan view of a diffusion member according to another embodiment of the present invention.

[0067] Fig.15 and Fig.16 is a view for describing the diameter of a microlens forming a diffusion member according to another embodiment of the present invention.

[0068] Fig.17 yes Fig.15 An enlarged view of the first area (710R).

[0069] Fig.18 is a cross-sectional view of a diffusion member and a light source according to another embodiment of the present invention.

[0070] Fig.19 A Gaussian function distribution with an average diameter of 300 μm and a standard deviation of 2 μm is shown.

[0071] Fig. 20 is an example of a rejection sampling process according to an embodiment of the present invention.

[0072] Fig.21 The diameter of the microlens designed according to the embodiment of the present invention and the diffraction angle of each diffraction order are shown.

[0073] Fig.22a is a plan view of a three-dimensional graph of a microlens array with uniform diameter, Figure 22b is a stereogram of a three-dimensional image of a microlens array with uniform diameter.

[0074] Fig.23a is a plan view of a three-dimensional image of a microlens array according to another embodiment of the present invention, Figure 23b is a stereogram of a three-dimensional image of a microlens array according to yet another embodiment of the present invention.

[0075] Fig.24a The Gaussian function distribution with an average diameter of 300.2 μm and a standard deviation of 10.94 μm in the X direction is shown. Figure 24bA Gaussian function distribution with an average diameter of 301.2 μm and a standard deviation of 11.3 μm in the Y direction is shown.

[0076] Fig.25a A Gaussian function distribution is shown with an average field of illumination (FoI) of 54.02 degrees in the X direction and a standard deviation of 0.9746 degrees, Fig.25b A Gaussian function distribution set to have an average FoI of 62.06 degrees and a standard deviation of 0.9323 degrees in the Y direction is shown.

[0077] Fig.26 The diameter and FoI of a microlens designed according to an embodiment of the present invention are shown.

[0078] Fig. 27 Shown according to Fig.26 The center position of the designed microlens array.

[0079] Fig.28a is based on Fig.26 The FoI diagram of the design in the X direction, Fig.28b is based on Fig.26 FoI diagram of the design in the Y direction.

[0080] Fig.29 is based on Fig.29 Glowing image for your design.

[0081] Fig.30 is a plan view of a microlens array according to still another embodiment of the present invention.

[0082] Fig.31 is a plan view of a microlens array according to still another embodiment of the present invention.

[0083] Fig.32 is a plan view of a microlens array according to still another embodiment of the present invention.

[0084] Fig.33 1 is a view for describing the diameters of microlenses forming a microlens array according to still another embodiment of the present invention.

[0085] Fig.34 yes Fig.32 Example of the first region (1710R).

[0086] Fig.35 is an exploded view of a camera module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0087] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0088] However, the technical spirit of the present invention is not limited to some of the described embodiments, but can be implemented in various different forms, and one or more components in the embodiments can be used by selective coupling or replacement without departing from the scope of the technical spirit of the present invention.

[0089] In addition, unless explicitly and specifically defined and described, the terms (including technical terms and scientific terms) used in the embodiments of the present invention may be interpreted as having the same meaning as that generally understood by technicians in the field to which the present invention belongs, and the meaning of general terms such as terms defined in dictionaries may be interpreted in consideration of the contextual meaning of the relevant technology.

[0090] Furthermore, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention.

[0091] In this specification, unless otherwise specified in a phrase, a singular form may include a plural form, and when described as "at least one (or one or more) of A, B and C", it may include one or more of all possible combinations of A, B and C.

[0092] Furthermore, terms such as first, second, A, B, (a), and (b) may be used to describe components of embodiments of the present invention.

[0093] These terms are used only to distinguish one component from another component, and these terms do not limit the nature, sequence, order, etc. of the corresponding components.

[0094] In addition, when a first component is described as being “connected,” “coupled” or “bonded” to a second component, this may include a case where the first component is directly connected, coupled or bonded to the second component, and may also include a case where the first component is “connected,” “coupled” or “bonded” to the second component via other components present between the first and second components.

[0095] Furthermore, when a specific component is described as being formed or disposed “on” or “under” another component, the term “on…” or “under” may include not only a case where the two components are in direct contact with each other but also a case where one or more other components are formed or disposed between the two components. Furthermore, when described as “on…” or “under…”, this may include not only a meaning based on an upward direction of one component but also a meaning based on a downward direction of one component.

[0096] The camera device according to an embodiment of the present invention may be a camera that extracts depth information using a time-of-flight (TOF) function. Therefore, the camera device may be used interchangeably with a TOF camera device, a TOF camera module, a TOF camera, and the like.

[0097] Figure 1 is a block diagram of a camera apparatus according to an embodiment of the present invention, Figure 2 is a view for describing an output light signal output by a camera apparatus according to an embodiment of the present invention.

[0098] refer to Figure 1 , a camera apparatus 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 .

[0099] The light emitting unit 100 may generate and output an output light signal in the form of a pulse wave or a continuous wave. The continuous wave may be in the form of a sine wave or a square wave. By generating an output light signal in the form of a pulse wave or a continuous wave, the camera device 1000 may detect a time difference or a phase difference between an output light signal output from the light emitting unit 100 and an input light signal input to the light receiving unit 200 after being reflected from an object. In the present specification, the output light may be light output from the light emitting unit 100 and incident on an object, and the input light may be light output from the light emitting unit 100 and reaching an object, then reflected from the object and input to the light receiving unit 200. Based on the object, the output light may be incident light, and the input light may be reflected light.

[0100] refer to Figure 2 In (a), the light emitting unit 100 may generate light pulses at a fixed period. The light emitting unit 100 may generate light pulses at a predetermined pulse repetition period t modulation Generate a pulse with a predetermined width t pulse of light pulses.

[0101] refer to Figure 2 In (b), a predetermined number of light pulses generated by the light emitting unit 100 may be combined (into a group) to generate a phase pulse. The light emitting unit 100 may generate a phase pulse having a predetermined period t phase and the predetermined phase pulse width t exposure The phase pulse width can be called t inlumination or integration Here, a phase pulse period t phase Can correspond to a subframe. A subframe can be called a phase frame. A predetermined number of phase pulse cycles can be combined. Make four phase pulse cycles t phase The grouping method can be called the 4-phase method. phase The grouped method may be referred to as an 8-phase method.

[0102] refer to Figure 2In (c), a predetermined number of phase pulses generated by the light emitting unit 100 may be combined to generate one frame pulse. The light emitting unit 100 may generate a frame pulse having a predetermined frame pulse period t frame and the predetermined frame pulse width t phase group(sub-frame group) Here, a frame pulse period t frame Therefore, when capturing an object at 10 FPS, 10 frame pulse cycles can be repeated per second. frame In the 4-phase method, one frame may include 4 subframes. That is, one frame may be generated by 4 subframes. In the 8-phase method, one frame may include 8 subframes. That is, one frame may be generated by 8 subframes.

[0103] In the above description, terms such as light pulse, phase pulse, and frame pulse are used, but the present invention is not limited thereto.

[0104] Reference again Figure 1 , the light emitting unit 100 may 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 with a wavelength of 770 to 3000 nm. Alternatively, the light generated by the light source 110 may be visible light with a wavelength of 380 to 770 nm. The light source 110 may use a light emitting diode (LED) and have a form in which a plurality of light emitting diodes are arranged in a regular pattern. In addition, the light source 110 may include an organic light emitting diode (OLED) or a laser diode (LD). Alternatively, the light source 110 may be a vertical cavity surface emitting laser (VCSEL). VCSEL is one of the laser diodes used to convert an electrical signal into an optical signal, and may 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 flashes (on / off) at fixed time intervals to generate an output optical signal in the form of a pulse wave or a continuous wave. The fixed time interval may be the frequency of the output optical signal.

[0105] The diffusion member 120 may receive light output from the light source 110, then diffract the received light and output the diffracted light. The diffusion member 120 may collect light and convert the collected light into parallel light. The diffusion member 120 may be a micro lens array (MLA).

[0106] Although not shown, the light emitting unit 100 may further include an additional lens assembly. The lens assembly (not shown) may collect light output from the light source 110 and output the collected light outwardly. The lens assembly may be arranged to be spaced apart from the light source 110 above the light source 110. Here, "above the light source 110" may be a 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, the lenses may be aligned relative to a central axis to form an optical system. Here, the central axis may be the same as the optical axis of the optical system.

[0107] The light receiving unit 200 may receive light reflected from an object. The light receiving unit 200 may receive an optical signal reflected from an object. In this case, the received optical signal may be an optical signal output by the light emitting unit 100 and reflected from the object.

[0108] The light receiving unit 200 may include a lens assembly, an optical filter, and a sensor to receive an optical signal. The optical signal reflected from the object may pass through the lens assembly. The optical axis of the lens assembly may be aligned with the optical axis of the sensor. The optical filter may be disposed between the lens assembly and the sensor. The optical filter may be disposed on the optical path between the object and the sensor. The optical filter may filter light having a predetermined wavelength range. The optical filter may transmit light of a specific wavelength band. The optical filter may transmit light having a specific wavelength. For example, the optical filter may transmit light in an infrared band and block light outside the infrared band. The sensor may sense light. The sensor may sense an optical signal. The sensor may be an image sensor for sensing an optical signal. The sensor may detect an optical signal and output the detected optical signal as an electrical signal. The sensor may detect light having a wavelength corresponding to the wavelength of light output from the light emitting element. For example, the sensor may detect light in an infrared band.

[0109] For example, the sensor may receive an input light signal in synchronization with a flashing cycle of the light source 110. Specifically, the sensor may receive light in phase and out of phase with an output light signal output from the light source 110. That is, the sensor may repeatedly perform an operation of receiving an input light signal when the light source is turned on and an operation of receiving an input light signal when the light source is turned off. The sensor may generate an electrical signal corresponding to each reference signal using a plurality of reference signals having different phase differences. The frequency of the reference signal may be set to be the same as the frequency of the output light signal output from the light source 110. Therefore, when the light source 110 generates an output light signal using a plurality of frequencies, the sensor generates an electrical signal using a plurality of reference signals corresponding to each frequency. The electrical signal may include information about the amount of charge or voltage corresponding to each reference signal.

[0110] The number of reference signals according to an embodiment of the present invention may be four, i.e., C1 to C4 (not shown). Each of the reference signals C1 to C4 may have the same frequency as the output optical signal, but with a phase difference of 90 degrees. One C1 of the four reference signals may have the same phase as the output optical signal. The phase delay of the input optical signal is as much as the distance that the output optical signal is reflected and returned after being incident on the object. The sensor mixes the input optical signal with each reference signal. Then, the sensor may generate an electrical signal for each reference signal.

[0111] The sensor may be configured to have a structure in which a plurality of pixels are arranged in a grid shape. The sensor may be a complementary metal oxide semiconductor (CMOS) image sensor or a charge coupled device (CCD) image sensor. In addition, the sensor may include a TOF sensor for receiving IR light reflected from an object and measuring the distance using a time difference or a phase difference. For example, each pixel may include an in-phase receiving unit and an out-of-phase receiving unit, the in-phase receiving unit being used to receive an input light signal having the same phase as the waveform of the output light, and the out-of-phase receiving unit being used to receive an input light signal having a phase opposite to the phase of the waveform of the output light. When the in-phase receiving unit and the out-of-phase receiving unit are activated with a certain time difference, the amount of light received by the in-phase receiving unit and the out-of-phase receiving unit differs according to the distance to the object, and the distance to the object may be calculated using the above difference.

[0112] 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 next to the light emitting unit 100. The light receiving unit 200 may be arranged in the same direction as the light emitting unit 100.

[0113] The depth information generating unit 300 may generate depth information of the object using the input light signal input to the light receiving unit 200. For example, the depth information generating unit 300 may calculate the depth information of the object using the flight time required for the output light signal output from the light emitting unit 100 to be reflected from the object and then input to the light receiving unit 200. For example, the depth information generating unit 300 calculates the phase difference between the output light signal and the input light 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.

[0114] Specifically, the depth information generating unit 300 may calculate a phase difference between an output optical signal and an input optical signal using charge amount information of an electrical signal.

[0115] As described above, four electrical signals may be generated for each frequency of the output optical signal. Therefore, the depth information generating unit 300 may calculate the phase difference t between the output optical signal and the input optical signal using the following mathematical formula 1: d .

[0116] [Mathematical formula 1]

[0117]

[0118] Here, Q1 to Q4 represent the charge amounts of four electrical signals. Q1 represents the charge amount of the electrical signal corresponding to the reference signal having the same phase as the phase of the output optical signal. Q2 represents the charge amount of the electrical signal corresponding to the reference signal having a phase 180 degrees later than the phase of the output optical signal. Q3 represents the charge amount of the electrical signal corresponding to the reference signal having a phase 90 degrees later than the phase of the output optical signal. Q4 represents the charge amount of the electrical signal corresponding to the reference signal having a phase 270 degrees later than the phase of the output optical signal.

[0119] Then, the depth information generating unit 300 may calculate the distance between the object and the camera apparatus 100 using the phase difference between the output light signal and the input light signal. In this case, the depth information generating unit 300 may calculate the distance d between the object and the camera apparatus 1000 using Math 2 below.

[0120] [Mathematical formula 2]

[0121]

[0122] Here, c represents the speed of light, and f represents the frequency of the output light.

[0123] The control unit 500 controls the driving of the light emitting unit 100, the light receiving unit 200, and the depth information generating unit 300. The depth information generating unit 300 and the control unit 500 may be implemented in the form of a printed circuit board (PCB). In addition, the depth information generating unit 300 and the control unit 500 may be implemented in the form of different configurations. Alternatively, the control unit 500 may be included in a terminal provided with the camera device 1000 according to an embodiment of the present invention. For example, the control unit 500 may be implemented in the form of an application processor (AP) of a smartphone provided with the camera device 1000 according to an embodiment of the present invention.

[0124] Figure 3 is a schematic diagram of a light emitting unit according to an embodiment of the present invention.

[0125] refer to Figure 3 , the light emitting unit 100 according to the embodiment of the present invention includes a light source 110 and a diffusion member 120 .

[0126] According to an embodiment of the present invention, the light source 110 may include a plurality of light emitting elements 112. Specifically, the light source 110 may be implemented in the form of an array 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, a plurality of holes may be formed in the first surface of the substrate 111, and a diffusion member 120 may be disposed on the substrate 111 corresponding to the plurality of holes. The light source 110 outputs light through the holes, and the light may be output at a predetermined divergence angle. The plurality of light emitting elements 112 may be VCSELs.

[0127] The diffusion member 120 may 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 may have a main body portion 121 and a plurality of microlenses 122 formed integrally. In this case, the main body portion 121 and the microlenses 122 may be formed of the same material. The main body portion 121 may have a plate shape. Therefore, the diffusion member 120 may be a microlens array (MLA).

[0128] The diffusion member 120 may be divided into a first surface receiving light from the light source 110 and a second surface outputting light. The second surface of the diffusion member 120 may include a horizontal surface or a curved surface, and a plurality of micro lenses 122 may be disposed on the first surface of the diffusion member 120.

[0129] The plurality of microlenses 122 may have a predetermined diameter. The plurality of microlenses 122 may have a diameter set so that the maximum value of the light flux concentration of the plurality of microlenses does not exceed a predetermined value. Here, light flux concentration may refer to a ratio of the light flux incident on one microlens to the total energy output by the light source 110. Therefore, the safety of the user's eyes may be improved by dispersing the energy concentrated on one microlens. Here, the user may be an object of the camera device 1000, a person located near the camera device 1000, or the like.

[0130] The diffusion member 120 converts the laser beam output by the light emitting element 112 into a surface illumination pattern. Here, the surface illumination pattern is a form in which light is uniformly distributed in a predetermined area, and can be used interchangeably with a flood illumination pattern, a surface light source pattern, etc. Here, uniformity can mean that light is continuously distributed in space. In the case of a surface illumination pattern, since the light is uniformly (continuously) distributed in space, there is an advantage in that when the light of the surface illumination pattern is irradiated onto an object, high-resolution depth information can be acquired.

[0131] In this case, when the size of the diffusion member 120 (ie, a plurality of microlenses forming the microlens array) is uniform, constructive interference or destructive interference may occur due to coherent characteristics of the laser beam, and thus the uniformity of the surface illumination pattern may be deteriorated.

[0132] More specifically, when a laser beam having coherent characteristics passes through a slit having a constant grating period, diffraction occurs according to Mathematical Formula 3. That is, when the phase of light having a specific wavelength satisfies the grating period, constructive interference and destructive interference occur, thereby causing diffraction, and due to constructive interference, a phenomenon in which light becomes brighter or darker at a specific angle may occur, which can be defined as a diffraction order.

[0133] [Mathematical formula 3]

[0134] dsinθ=mλ

[0135] Where d is the grating period, θ is the diffraction angle, m is the diffraction order, and λ is the wavelength.

[0136] In addition, since constructive interference and destructive interference are further enhanced as the number of grating periods of the slit increases, the intensity of light at the diffraction angle θ is expressed by Mathematical Formula 4.

[0137] [Formula 4]

[0138]

[0139] Where I is the intensity of the electric field light, d is the grating period, N is the number of grating periods within 1 mm (d / 1 mm), θ is the diffraction angle, and λ is the wavelength.

[0140] The embodiments of the present invention are directed to reducing the deviation of the light intensity I according to Math. 4 and improving the uniformity of the surface illumination pattern through the design of the micro lenses forming the diffusion member.

[0141] According to an embodiment of the present invention, the diffusion member may be divided into a plurality of regions and may include micro lenses having different diameters for each region.

[0142] Figure 4 is a plan view of a diffusion member according to an embodiment of the present invention, Figure 5 and Figure 6 is a view for describing the diameter of a microlens forming a diffusion member according to one embodiment of the present invention, and Figure 7 is a cross-sectional view of a diffusion member and a light source according to an embodiment of the present invention.

[0143] refer to Figures 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, in the description of the diffusion member 400, the reference numerals will be omitted. Figures 1 to 3 The same contents as those described regarding the diffusion member 120 are described repeatedly.

[0144] Here, the first region 410R may be a region including the center of the diffusion member 400 .

[0145] 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 with the optical axis direction. In addition, the plurality of first microlenses 410 are arranged in the first region 410R along a second direction perpendicular to the first direction, the plurality of second microlenses 420 are arranged in the second region 420R along the second direction, and the plurality of third microlenses 430 are arranged in the third region 430R along the second direction. In this case, the plurality of first microlenses 410 arranged in the outermost columns and the outermost rows of the first region 410R may be 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 may be arranged adjacent to the plurality of third microlenses 430 arranged in the third region 430R. The plurality of second microlenses 420 may be arranged in a row to surround the outermost portion of the first region 410R, and the plurality of third microlenses 430 may be arranged in a row to surround the second region 420R. Therefore, the first microlens 410 may be arranged 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, and the third microlens 430 may be arranged on the other side surface of each second microlens 420. That is, the second microlens 420 may not be arranged 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. Likewise, the third microlens 430 may not be arranged 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. The distance from the center of the diffusion member 400 (i.e., the microlens array) to the second microlens 420 may be greater 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 greater than the distance from the center of the microlens array to the second microlens 420.

[0146] In this specification, the first region 410R to the third region 430R including the first microlens to the third microlens having the first diameter to the third diameter are mainly described, but this is for the convenience of description and the present invention is not limited thereto. The 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.

[0147] Here, the first diameter P1, the second diameter P2, and the third diameter P3 may be used interchangeably with the first pitch P1, the second pitch P2, and the third pitch P3, respectively. Here, the diameter may refer to the length of the microlens in the first direction or the second direction. However, the diameter may also refer to the length of the microlens in a direction other than the first direction and the second direction.

[0148] According to an embodiment of the present invention, the first region 410R, the second region 420R, and the third region 430R are disposed in a region a defined by Math.

[0149] [Mathematical formula 5]

[0150] a=2D tanθ

[0151] Where a represents 1 / e 2 The width of the area reached by the maximum light intensity is 1 / e times, D represents the distance from the light source 110 to the diffusion member 400, and θ can be defined as 1 / e of the light source 110. 2 times the angle of maximum light intensity output.

[0152] In this regard, refer to Figure 7 , the light source 110 and the diffusion member 400 are arranged to be spaced apart from each other by a predetermined distance D. In addition, the light emitting element 112 outputs light at a predetermined angle θ. When a virtual normal line perpendicular to the substrate 111 is drawn from the center of the light emitting element 112, an angle θ / 2 formed by the virtual normal line 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 specifications, and the divergence angle θ of the light output by the plurality of light emitting elements 112 may be the same.

[0153] For example, the light emitting element 112 may emit a predetermined amount of energy from -20 degrees to 20 degrees relative to the optical axis. However, it can be seen that the amount of energy is close to zero at an angle of -15 degrees, +15 degrees, below -15 degrees, or above 15 degrees. That is, most of the energy exists in a predetermined angle relative to the optical axis of the light emitting element. Therefore, it is inefficient to set all angles at which the amount of energy is not zero as the divergence angle of the light emitting element, while it is efficient to set the angle at which a predetermined amount or more of energy is emitted as the divergence angle of the light emitting element. Therefore, the divergence angle of the light source 110 may be set to 1 / e of the output light source 110.2 The angle is times the maximum light intensity, and the area a defined by Mathematical Formula 5 can be called the effective light area.

[0154] In this case, the first diameter P1, the second diameter P2, and the third diameter P3 may be different. In this way, when the first region 410R, the second region 420R, and the third region 430R of the microlenses having different diameters are arranged in the effective light region, the energy of the output light is dispersed, thereby improving the safety of the user's eyes and preventing uniformity degradation due to interference.

[0155] 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, and 430R has a correlation relationship with the diameter of the microlenses included in at least one of the first to third regions 410R, 420R, and 430R and the diameter of the microlenses included in another region surrounding at least one of the first to third regions 410R, 420R, and 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, and 430R have a correlation relationship with the diameter of the microlenses included in another region surrounding at least one of the first to third regions 410R, 420R, and 430R. The number of region-specific microlenses according to an embodiment of the present invention can be expressed by Mathematical Formula 6.

[0156] [Mathematical formula 6]

[0157] P n × n =P n+1 ×(x n -1)

[0158] Among them, P n represents the diameter of the microlens set in the nth region, P n+1 represents the diameter of the microlens arranged in the (n+1)th region, x n represents the number of microlenses arranged along the first direction or the number of microlenses arranged along the second direction in the nth region. n It does not refer to the number of all microlenses included in the nth region. For example, x1 may be four microlenses arranged along the first direction or the second direction in the first region, x2 may be five microlenses arranged along the first direction or the second direction in the second region, and x3 may be six microlenses arranged along the first direction or the second direction in the third region.

[0159] Therefore, the number of microlenses included in the nth region may have a correlation relationship with the diameter of the microlenses included in the nth region and the diameter of the microlenses included in the (n+1)th region surrounding the nth region. The number and diameter of the microlenses included in the nth region may have a correlation relationship with the diameter of the microlenses included in the (n+1)th region surrounding the nth region.

[0160] For example, the number of first microlenses 410 included in the first region 410R may have a correlation relationship with a first diameter P1 of the first microlenses 410 included in the first region 410R and a second diameter P2 of the second microlenses 420 included in the second region 420R. The number of first microlenses 410 included in the first region 410R and the first diameter P1 may have a correlation relationship with a second diameter P2 of the second microlenses 420 included in the second region 420R. In addition, the number of second microlenses 420 included in the second region 420R may have a correlation relationship with a second diameter P2 of the second microlenses 420 included in the second region 420R and a third diameter P3 of the third microlenses 430 included in the third region 430R. The number of second microlenses 420 included in the second region 420R and the second diameter P2 may have a correlation relationship with a third diameter P3 of the third microlenses 430 included in the third region 430R.

[0161] For example, the product of the first diameter P1 and the number of the first microlenses 410 disposed in the first direction may be equal to the product of the second diameter P2 and a number less than one of the number of the first microlenses 410 disposed in the first direction, and the product of the second diameter P2 and the number of the second microlenses 420 disposed in the first direction may be equal to the product of the third diameter P3 and a number less than one of the number of the second microlenses 420 disposed in the first direction. Therefore, constructive interference and destructive interference due to overlap of diffraction angles according to diffraction orders of each region can be minimized, and arrangement of the microlens array is easy.

[0162] Table 1 is an example of a microlens array according to an embodiment of the present invention under the condition that the distance D from the light source 110 to the diffusion member 400 exceeds 5.7 mm (D>5.7 mm).

[0163] Table 1

[0164]

[0165] Here, n represents the order of the regions, diameter is the diameter of the region-specific microlens, and number is the number of microlenses repeatedly arranged in the first direction or the number of microlenses repeatedly arranged in the second direction.

[0166] For example, four microlenses with a diameter of 300 μm can be arranged in a row along the first direction in the first region, five microlenses with a diameter of 400 μm can be arranged in a row along the first direction in the second region, six microlenses with a diameter of 500 μm can be arranged in a row along the first direction in the third region, seven microlenses with a diameter of 600 μm can be arranged in a row along the first direction in the fourth region, eight microlenses with a diameter of 700 μm can be arranged in a row along the first direction in the fifth region, and nine microlenses with a diameter of 800 μm can be arranged in a row along the first direction in the sixth region.

[0167] Referring to Mathematical Formula 6, when the diameter is 300 μm in the case of n=1 and the diameter is 400 μm in the case of n=2, the number of microlenses arranged in a row in the first direction when n=1 may be 4. Similarly, when the diameter is 400 μm in the case of n=2 and the diameter is 500 μm in the case of n=3, the number of microlenses arranged in a row in the first direction when n=2 may be 5.

[0168] In addition, when the diameter is 800 μm in the case of n=6 and the diameter is 900 μm in the case of n=7, the number of microlenses arranged in a line in the first direction may be 9 when n=6.

[0169] When the microlens array is arranged according to these conditions, constructive interference and destructive interference caused by the overlap of diffraction angles according to the diffraction orders of each area can be minimized, and since three or more types of microlenses with different diameters are arranged in the effective optical area, the arrangement of the microlens array can be safer for the user's eyes.

[0170] Table 2 is an example of the microlens array according to the embodiment of the present invention under the condition that the distance D from the light source 110 to the diffusion member 400 exceeds 1.2 mm (D>1.2 mm).

[0171] Table 2

[0172]

[0173] Wherein, n represents the order of the region, the diameter is the diameter of the region-specific microlens, and the number is the number of microlenses repeatedly arranged in the first direction or the number of microlenses repeatedly arranged in the second direction. It can be seen from Table 2 that the microlens array is also designed to satisfy Mathematical Formula 6. When the microlens array is arranged according to these conditions, constructive interference and destructive interference caused by the overlap of diffraction angles according to the diffraction orders of each region can be minimized, and since three or more types of microlenses with different diameters are arranged in the effective optical area, the arrangement of the microlens array can be safer for the user's eyes.

[0174] Table 3 is an example of the microlens array according to the embodiment of the present invention under the condition that the distance D from the light source 110 to the diffusion member 400 exceeds 0.35 mm (D>0.35 mm).

[0175] Table 3

[0176]

[0177]

[0178] Wherein, n represents the order of the region, the diameter is the diameter of the region-specific microlens, and the number is the number of microlenses repeatedly arranged in the first direction or the number of microlenses repeatedly arranged in the second direction. It can be seen from Table 3 that the microlens array is also designed to satisfy Mathematical Formula 6. When the microlens array is arranged according to these conditions, constructive interference and destructive interference caused by the overlap of diffraction angles according to the diffraction order of each region can be minimized, and since three or more types of microlenses with different diameters are arranged in the effective optical area, the arrangement of the microlens array can be safer for the user's eyes.

[0179] Referring to Tables 1 to 3, it can be seen that the diameter of the microlens varies according to the distance D between the light source 110 and the diffusion member 400. Here, the distance D between the light source 110 and the diffusion member 400 may be a vertical distance between the first surface of the light source 110 and the first surface of the diffusion member 400. The first surface of the light source 110 is a surface provided with a hole. The first surface of the diffusion member 400 is a surface where each of the plurality of microlenses 410, 420, and 430 receives light from the light source 110. Specifically, since the plurality of microlenses 410, 420, and 430 are provided on the first surface of the diffusion member 400 in an embossing form, the first surface of the diffusion member 400 may be a surface connecting points where the optical axis passes through each of the plurality of microlenses 410, 420, and 430. Therefore, the distance between the diffusion member 400 and the light source 110 may be a vertical distance between a point where the optical axis of the microlenses 410, 420, and 430 passes and the first surface of the light source 110.

[0180] It can be seen that, as shown in Table 1, when D>5.7mm, the diameter of the microlens is hundreds of microns, such as 300μm or more, for example, ranging from 300μm to 800μm; as shown in Table 2, when D>1.2mm, the diameter of the microlens is tens of microns to hundreds of microns, such as 50μm or more, for example, ranging from 50μm to 120μm; as shown in Table 3, when D>0.35mm, the diameter of the microlens is tens of microns, such as 20μm or more, for example, ranging from 20μm to 70μm. In this way, when the diameter of the microlens varies according to the distance D between the light source 110 and the diffusion member 400, it is possible to reduce the concentration of light flux on a specific microlens, thereby making the user's eyes safe.

[0181] Meanwhile, 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 may protrude toward the direction of the light source 110. In the present specification, the direction from the diffusion member 400 to the light source 110 may be referred to as a third direction perpendicular to the first direction and the second direction, which are plane 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.

[0182] In this case, the protrusion height h1 of the plurality of first microlenses 410, the protrusion height h2 of the plurality of second microlenses 420, and the protrusion height h3 of the plurality of third microlenses 430 may be different. Therefore, since the boundaries of the first region 410R, the second region 420R, and the third region 430R are determined by the protrusion height of each microlens, the periodicity of the grating is destroyed, and constructive interference and destructive interference caused by the overlap of the diffraction angles according to the diffraction orders of each region can be minimized.

[0183] In this case, 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 may have aspherical shapes, respectively. For example, the aspherical shapes of the first microlenses 410, the second microlenses 420, and the third microlenses 430 may be defined by image height, radius of curvature, and cone constant. For example, the aspherical shapes of the first microlenses 410, the second microlenses 420, and the third microlenses 430 may be defined by Mathematical Formula 7.

[0184] [Formula 7]

[0185]

[0186] Among them, Z represents the aspherical shape of the lens, h represents the image height, R represents the radius of curvature, and K represents the cone constant.

[0187] Since the microlens array is arranged in a two-dimensional manner, the aspherical shapes of the first microlens 410 , the second microlens 420 , and the third microlens 430 may be defined by Math Formula 8.

[0188] [Mathematical formula 8]

[0189]

[0190] Where x represents the image height on the X axis, y represents the image height on the Y axis, and R x Indicates the X-axis curvature radius, R y Indicates the Y-axis curvature radius, K x represents the X-axis cone constant, K y Represents the Y-axis cone constant.

[0191] Therefore, the FoI of the laser beam passing through the microlens array can be defined, and the light flux on a specific microlens can be concentratedly set not to exceed a predetermined value.

[0192] Hereinafter, simulation results of examples according to the present invention and comparative examples will be described.

[0193] Figure 8 (a) is a plan view of a three-dimensional image of a microlens array according to a comparative example, Figure 8 (b) is a stereogram of a three-dimensional image of a microlens array according to a comparative example, Fig. 9 shows the results of Monte Carlo ray tracing simulation of a microlens array according to a comparative example, Fig.10 (a) shows the result of FDTD simulation of the microlens array according to the comparative example, Fig.10 (b) is Fig.10 Magnified images of some areas in (a).

[0194] Fig.11 (a) is a plan view of a three-dimensional image of a microlens array according to an embodiment, Fig.11 (b) is a stereogram of a three-dimensional image of a microlens array according to an embodiment, Fig.12 shows the results of Monte Carlo ray tracing simulation of a microlens array according to an embodiment, Fig.13 (a) shows the result of FDTD simulation of the microlens array according to the embodiment, Fig.13 (b) is Fig.13 Magnified images of some areas in (a).

[0195] The microlens array according to the comparative example is designed such that a plurality of microlenses are arranged in an array shape and all of the plurality of microlenses have the same diameter.

[0196] refer to Figure 8 Middle (a), Figure 8 Middle (b), Fig. 9 , Fig.10 (a) and Fig.10 In (b), as a result of the Monte Carlo ray tracing simulation of the microlens array according to the comparative example, the edge angle of the peripheral portion is formed to be relatively sharp, and as a result of the FDTD simulation of the microlens array according to the comparative example, the constructive interference due to diffraction is relatively strong.

[0197] On the contrary, reference Fig.11 Middle (a), Fig.11 Middle (b), Fig.12 , Fig.13 (a) and Fig.13 In (b), as a result of the Monte Carlo ray tracing simulation of the microlens array according to the embodiment, it can be seen that there is no edge angle of the surrounding part compared with the comparative example, and as a result of the FDTD simulation of the microlens array according to the embodiment, it can be seen that the constructive interference caused by diffraction is significantly weakened.

[0198] Fig.14 is a plan view of a diffusion member according to another embodiment of the present invention, Fig.15 and Fig.16 is a view for describing the diameter of a microlens forming a diffusion member according to another embodiment of the present invention, Fig.17 yes Fig.15 An enlarged view of the first region (710R) of Fig.18 FIG. 1 is a cross-sectional view of a diffusion member and a light source according to another embodiment of the present invention. Figures 1 to 13 Duplicate descriptions of the same content.

[0199] refer to Figures 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, in the description of the diffusion member 700, the reference numerals will be omitted. Figures 1 to 3 The same contents as those described about the diffusion member 120 are described repeatedly.

[0200] 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 be the center of the microlens array of the diffusion member 700.

[0201] 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 with the optical axis direction. In addition, the plurality of first microlenses 710 are arranged in the first region 710R along a second direction perpendicular to the first direction and intersecting with the optical axis direction, the plurality of second microlenses 720 are arranged in the second region 720R along the second direction, and the plurality of third microlenses 730 are arranged in the third region 730R along the second direction. In this case, the plurality of first microlenses 710 arranged in the outermost columns and the outermost rows of the first region 710R may be arranged adjacent to the plurality of second microlenses 720 arranged in the second region 720R, and the plurality of second microlenses 720 arranged in the second region 720R may be arranged adjacent to the plurality of third microlenses 730 arranged in the third region 730R. The plurality of second microlenses 720 may be arranged in a row to surround the outermost portion of the first region 710R, and the plurality of third microlenses 730 may be arranged in a row to surround the second region 720R. Therefore, the first microlens 710 may be arranged 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, and the third microlens 730 may be arranged on the other side surface of each second microlens 720. That is, the second microlens 720 may not be arranged 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. Likewise, the third microlens 730 may not be arranged 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. The distance from the center of the diffusion member 700 (i.e., 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 be greater than the distance from the center of the microlens array to the second microlens 720.

[0202] In this specification, the first region 710R to the third region 730R including the first microlenses to the third microlenses having the first average diameter to the third average diameter are mainly described, but this is for the convenience of description and the present invention is not limited thereto. The 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 diameter, a fifth region surrounding the fourth region and including a plurality of fifth microlenses having a fifth diameter, and the like.

[0203] Here, the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3 may be used interchangeably with the first average spacing AP1, the second average spacing AP2, and the third average spacing AP3, respectively. Here, the diameter may refer to the length of the microlens in the first direction or the second direction. However, the diameter may also refer to the length of the microlens in a direction other than the first direction and the second direction. For example, the diameter may refer to the length of the microlens array in the first direction, the second direction, or the third direction (i.e., the optical axis direction).

[0204] According to an embodiment of the present invention, the first region 710R, the second region 720R, and the third region 730R are disposed within a region a defined by Math.

[0205] [Mathematical formula 9]

[0206] a=2D tanθ

[0207] Where a represents 1 / e 2 The width of the area reached by the maximum light intensity is 1 / e times, D represents the distance from the light source 110 to the diffusion member 700, and θ can be defined as 1 / e of the light source 110. 2 times the angle of maximum light intensity output.

[0208] In this regard, refer to Fig.18 , the light source 110 and the diffusion member 700 are arranged to be spaced apart from each other by a predetermined distance D. In addition, the light emitting element 112 outputs light at a predetermined angle θ. When a virtual normal line perpendicular to the substrate 111 is drawn from the center of the light emitting element 112, an angle θ / 2 formed by the virtual normal line 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 specifications, and the divergence angle θ of the light output by the plurality of light emitting elements 112 may be the same.

[0209] For example, the light emitting element 112 may emit a predetermined amount of energy from -20 degrees to 20 degrees relative to the optical axis. However, it can be seen that the amount of energy is close to zero at an angle of -15 degrees, +15 degrees, below -15 degrees, or above 15 degrees. That is, most of the energy exists in a predetermined angle relative to the optical axis of the light emitting element. Therefore, it is inefficient to set all angles at which the amount of energy is not zero as the divergence angle of the light emitting element, while it is efficient to set the angle at which a predetermined amount or more of energy is emitted as the divergence angle of the light emitting element. Therefore, the divergence angle of the light source 110 may be set to 1 / e of the output light source 110. 2 The angle is times the maximum light intensity, and the area a defined by Mathematical Formula 9 can be called the effective light area.

[0210] In this case, the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3 may be different. According to an embodiment of the present invention, the second average diameter AP2 may be greater than the first average diameter AP1, and the third average diameter AP3 may be greater than the second average diameter AP2. According to an embodiment of the present invention, the second average diameter AP2 may be more than 1.1 times the first average diameter AP1, and the third average diameter AP3 may be more than 1.1 times 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 greater than the ratio of the third average diameter AP3 to the second average diameter AP2. Therefore, the energy of the output light can be dispersed, thereby improving the safety of the user's eyes and preventing uniformity degradation due to interference.

[0211] like Fig.17 As shown, according to an embodiment of the present invention, a plurality of first microlenses 710 having a first average diameter AP1 in a first region 710R may have different diameters. Here, the diameter may be a diameter in a first direction, a diameter in a second direction perpendicular to the first direction, or a diameter in a third direction as an 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, a plurality of first microlenses 710 may have different diameters in a range of 0.95 to 1.05 times the first average diameter AP1, preferably in a range of 0.97 to 1.03 times the first average diameter AP1, and more preferably in a range of 0.98 to 1.02 times the first average diameter AP1. Therefore, it is possible to minimize constructive interference and destructive interference caused by overlapping diffraction angles according to the diffraction orders of the plurality of first microlenses 710 in the first region 710R.

[0212] Likewise, the plurality of second microlenses 720 having the second average diameter AP2 in the second region 720R may have different diameters. According to an embodiment of the present invention, the plurality of second microlenses 720 may have different diameters in the range of 0.95 to 1.05 times the second average diameter AP2, preferably in the range of 0.97 to 1.03 times the second average diameter AP2, and more preferably in the range of 0.98 to 1.02 times the second average diameter AP2. Therefore, constructive interference and destructive interference caused by overlapping diffraction angles of the plurality of second microlenses 720 in the second region 720R according to the diffraction orders can be minimized.

[0213] Likewise, the plurality of third microlenses 730 having the third average diameter AP3 in the third region 730R may have different diameters. According to an embodiment of the present invention, the plurality of third microlenses 730 may have different diameters in the range of 0.95 to 1.05 times the third average diameter AP3, preferably in the range of 0.97 to 1.03 times the third average diameter AP3, and more preferably in the range of 0.98 to 1.02 times the third average diameter AP3. Therefore, constructive interference and destructive interference caused by overlapping diffraction angles of the plurality of third microlenses 730 in the third region 430R can be minimized.

[0214] To this end, 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 may be designed respectively 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 disposed in the first region 710R may have different diameters. When the diameters of the plurality of second microlenses 720 are designed by random number generation, the plurality of second microlenses 720 disposed in the second region 720R may have different diameters. When the diameters of the plurality of third microlenses 730 are designed by random number generation, the plurality of third microlenses 730 disposed in the third region 730R may have different diameters. When the plurality of microlenses included in each region have different diameters, constructive interference and destructive interference caused by overlapping diffraction angles according to diffraction orders can be minimized.

[0215] According to an embodiment of the present invention, the random number generation of the diameter of the microlens can be designed using a Gaussian function distribution according to a preset average diameter and standard deviation. According to an embodiment of the present invention, the diameters of the multiple microlenses included in each region can be extracted by rejection sampling the same number of times as the number of the multiple microlenses included in each region.

[0216] Mathematical formula 10 represents a Gaussian function.

[0217] [Formula 10]

[0218]

[0219] Here, x represents the variable, μ represents the mean, and σ represents the standard deviation.

[0220] That is, when the average diameter and standard deviation of each region are defined, Gaussian function distribution can be set. Fig.19 A Gaussian function distribution with an average diameter of 300 μm and a standard deviation of 2 μm is shown.

[0221] At the same time, it may be difficult to Fig.19Therefore, in the embodiment of the present invention, rejection sampling can be used to extract random numbers of the diameters of the plurality of microlenses in each region.

[0222] For this purpose, an envelope function of the Gaussian function of Mathematical Formula 10 is defined. The envelope function has a form similar to that of the Gaussian function of Mathematical Formula 10, and for all possible values ​​of the variable, its value is larger than that of the Gaussian function of Mathematical Formula 10. Mathematical Formula 11 is an envelope function of the Gaussian function of Mathematical Formula 10.

[0223] [Mathematical formula 11]

[0224]

[0225] Here, x represents the variable, μ represents the mean, and σ represents the standard deviation.

[0226] According to the embodiment of the present invention, a random number is extracted from the envelope function of Mathematical Formula 11. Mathematical Formula 12 is a function for generating a random number from Mathematical Formula 11, which is an envelope function, using a continuous uniform distribution.

[0227] [Mathematical formula 12]

[0228]

[0229] Fig. 20 is an example of a rejection sampling process according to an embodiment of the present invention. According to an embodiment of the present invention, the Gaussian function of mathematical formula 10 is compared with the envelope function of mathematical formula 11 under a random number extracted from mathematical formula 12, and it can be determined whether to accept or reject the random number based on the result of the comparison. When the Gaussian function of mathematical formula 10 is compared with the envelope function of mathematical formula 11, the farther from the average value, the greater the difference, and the closer to the average value, the smaller the difference. Therefore, it is advantageous to accept a random number close to the average value.

[0230] Fig.21 The diameter of the microlens designed according to the embodiment of the present invention and the diffraction angle of each diffraction order are shown.

[0231] refer to Fig.21 , the diameters of the plurality of first microlenses 710 are the result of the random number generation method according to the embodiment of the present invention being designed in the following manner: the first average diameter AP1 is set to 300 μm, the first standard deviation is set to 2.13, and the number of samples is set to 16. Therefore, it can be seen that the diameters of the plurality of first microlenses 710 are all different, and the diffraction angles of each diffraction order have no overlapping parts.

[0232] The diameters of the plurality of second microlenses 720 are the result of the random number generation method according to the embodiment of the present invention being designed in the following manner: the second average diameter AP2 is set to 400 μm, the second standard deviation is set to 3.42, and the number of samples is set to 16. Therefore, it can be seen that the diameters of the plurality of second microlenses 720 are all different, and the diffraction angles of each diffraction order have no overlapping parts.

[0233] The diameters of the plurality of third microlenses 730 are the result of the random number generation method according to the embodiment of the present invention being designed in the following manner: the third average diameter AP1 is set to 500 μm, the third standard deviation is set to 4.37, and the number of samples is set to 20. Therefore, it can be seen that the diameters of the plurality of third microlenses 730 are all different, and the diffraction angles of each diffraction order have no overlapping parts.

[0234] In this manner, since the diameters of the first to third microlenses 710 to 730 are all different, the diffraction angles of each diffraction order do not overlap with each other, and constructive interference and destructive interference due to the overlap of diffraction angles according to the diffraction orders can be minimized.

[0235] Meanwhile, according to an embodiment of the present invention, the number and average diameter of microlenses included in at least one of the first to third regions 710R, 720R, and 730R have a correlation with the average diameter of microlenses included in another region surrounding at least one of the first to third regions 710R, 720R, and 730R. The number of region-specific microlenses according to an embodiment of the present invention may be expressed by Mathematical Formula 13.

[0236] [Mathematical formula 13]

[0237] AP n × n =AP n+1 ×(x n +1)

[0238] Among them, AP n represents the average diameter of the microlenses set in the nth region, AP n+1 represents the average diameter of the microlenses arranged in the (n+1)th region, x n represents the number of microlenses arranged along the first direction or the number of microlenses arranged along the second direction in the nth region. nIt does not refer to the number of all microlenses included in the nth region. For example, x1 may be four microlenses arranged along the first direction or the second direction in the first region, x2 may be five microlenses arranged along the first direction or the second direction in the second region, and x3 may be six microlenses arranged along the first direction or the second direction in the third region. Here, both sides of Mathematical Formula 13 may have a predetermined error range. For example, when the error range of the calculated values ​​on the left and right sides of Mathematical Formula 13 is within ±3%, Mathematical Formula 13 may be considered to be valid.

[0239] Therefore, the number of microlenses included in the nth region may 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 may have a correlation with the average diameter of the microlenses included in the (n+1)th region surrounding the nth region.

[0240] For example, the number of first microlenses 710 included in the first region 710R may have a correlation relationship with a first average diameter AP1 of the first microlenses 710 included in the first region 710R and a second average diameter AP2 of the second microlenses 720 included in the second region 720R. The number of first microlenses 710 included in the first region 710R and the first average diameter AP1 may have a correlation relationship with a second average diameter AP2 of the second microlenses 720 included in the second region 720R. In addition, the number of second microlenses 720 included in the second region 720R may have a correlation relationship with a second average diameter AP2 of the second microlenses 720 included in the second region 720R and a third average diameter AP3 of the third microlenses 730 included in the third region 730R. The number of second microlenses 720 included in the second region 720R and the second average diameter AP2 may have a correlation relationship with a third average diameter AP3 of the third microlenses 730 included in the third region 730R.

[0241] For example, the product of the first average diameter AP1 and the number of the first microlenses 710 arranged in the first direction may be equal to the product of the second average diameter AP2 and the number of the first microlenses 710 arranged in the first direction less than one, and the product of the second average diameter AP2 and the number of the second microlenses 720 arranged in the first direction may be equal to the product of the third average diameter AP3 and the number of the second microlenses 720 arranged in the first direction less than one. Therefore, constructive interference and destructive interference caused by the overlap of the diffraction angles according to the diffraction orders of each region can be minimized, and the arrangement of the microlens array is easy.

[0242] Table 4 is an example of the microlens array according to the embodiment of the present invention under the condition that the distance D from the light source 110 to the diffusion member 700 exceeds 5.7 mm (D>5.7 mm).

[0243] Table 4

[0244] N Average diameter quantity 1 300μm 4 2 400μm 5 3 500μm 6 4 600μm 7 5 700μm 8 6 800μm 9

[0245] Here, n represents the order of the regions, diameter is the diameter of the region-specific microlens, and number is the number of microlenses repeatedly arranged in the first direction or the number of microlenses repeatedly arranged in the second direction.

[0246] For example, four microlenses with an average diameter of 300 μm can be arranged in a row along the first direction in the first region, five microlenses with an average diameter of 400 μm can be arranged in a row along the first direction in the second region, six microlenses with an average diameter of 500 μm can be arranged in a row along the first direction in the third region, seven microlenses with an average diameter of 600 μm can be arranged in a row along the first direction in the fourth region, eight microlenses with an average diameter of 700 μm can be arranged in a row along the first direction in the fifth region, and nine microlenses with an average diameter of 800 μm can be arranged in a row along the first direction in the sixth region.

[0247] Referring to Mathematical Formula 12, when the average diameter is 300 μm in the case of n=1 and the average diameter is 400 μm in the case of n=2, the number of microlenses arranged in a row in the first direction when n=1 may be 4. Similarly, when the average diameter is 400 μm in the case of n=2 and the average diameter is 500 μm in the case of n=3, the number of microlenses arranged in a row in the first direction when n=2 may be 5.

[0248] In addition, when the average diameter is 800 μm in the case of n=6 and the average diameter is 900 μm in the case of n=7, the number of microlenses arranged in a line in the first direction may be 9 when n=6.

[0249] When the microlens array is arranged according to these conditions, constructive interference and destructive interference caused by the overlap of diffraction angles according to the diffraction orders of each area can be minimized, and since three or more types of microlenses with different average diameters are arranged in the effective optical area, the arrangement of the microlens array can be safer for the user's eyes.

[0250] Table 5 is an example of the microlens array according to the embodiment of the present invention under the condition that the distance D from the light source 110 to the diffusion member 700 exceeds 1.2 mm (D>1.2 mm).

[0251] Table 5

[0252] N Average diameter quantity 1 50μm 6 2 60μm 7 3 70μm 8 4 80μm 9 5 90μm 10 6 100μm 11 7 110μm 12 8 120μm 13

[0253] Here, n represents the order of the regions, diameter is the diameter of the region-specific microlens, and number is the number of microlenses repeatedly arranged in the first direction or the number of microlenses repeatedly arranged in the second direction.

[0254] As can be seen in Table 5, the microlens array is also designed to satisfy Mathematical Formula 12. When the microlens array is arranged according to these conditions, constructive interference and destructive interference due to the overlap of diffraction angles according to the diffraction orders of each region can be minimized, and since three or more types of microlenses with different average diameters are arranged in the effective optical area, the arrangement of the microlens array can be safer for the user's eyes.

[0255] Table 6 is an example of the microlens array according to the embodiment of the present invention under the condition that the distance D from the light source 110 to the diffusion member 700 exceeds 0.35 mm (D>0.35 mm).

[0256] Table 6

[0257] N Average diameter quantity 1 20μm 3 2 30μm 4 3 40μm 5 4 50μm 6 5 60μm 7 6 70μm 8

[0258] Here, n represents the order of the regions, diameter is the diameter of the region-specific microlens, and number is the number of microlenses repeatedly arranged in the first direction or the number of microlenses repeatedly arranged in the second direction.

[0259] As can be seen in Table 6, the microlens array is also designed to satisfy Mathematical Formula 12. When the microlens array is arranged according to these conditions, constructive interference and destructive interference due to the overlap of diffraction angles according to the diffraction orders of each region can be minimized, and since three or more types of microlenses with different average diameters are arranged in the effective optical region, the arrangement of the microlens array can be safer for the user's eyes.

[0260] Referring to Tables 4 to 6, it can be seen that the average diameter of the microlenses varies according to 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 a 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 is a surface provided with holes. The first surface of the diffusion member 700 is a surface on which each of the plurality of microlenses 710, 720, and 730 receives light from the light source 110. Specifically, since the plurality of microlenses 710, 720, and 730 are provided on the first surface of the diffusion member 700 in a relief form, the first surface of the diffusion member 700 may be a surface connecting points through which the optical axis passes through each of the plurality of microlenses 710, 720, and 730. Therefore, the distance between the diffusion member 700 and the light source 110 may be a vertical distance between a point through which the optical axis of the microlenses 710, 720, and 730 passes and the first surface of the light source 110.

[0261] It can be seen that, as shown in Table 4, when D>5.7mm, the average diameter of the microlens is hundreds of microns, such as 300μm or more, for example, in the range of 300μm to 800μm; as shown in Table 5, when D>1.2mm, the average diameter of the microlens is tens of microns to hundreds of microns, such as 50μm or more, for example, in the range of 50μm to 120μm; as shown in Table 6, when D>0.35mm, the average diameter of the microlens is tens of microns, such as 20μm or more, for example, in the range of 20μm to 70μm. In this way, when the average diameter of the microlens varies according to the distance D between the light source 110 and the diffusion member 700, it is possible to reduce the concentration of light flux on a specific microlens, thereby making the user's eyes safe.

[0262] Meanwhile, according to an embodiment of the present invention, 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 may protrude toward the direction of the light source 110. In the present specification, the direction from the diffusion member 700 to the light source 110 may be referred to as a third direction perpendicular to the first direction and the second direction, which are plane directions of the diffusion 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.

[0263] In this case, 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. Here, the first average protrusion height h1, the second average protrusion height h2, and the third average protrusion height h3 may be used interchangeably with the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3, respectively. Therefore, since the boundaries of the first region 710R, the second region 720R, and the third region 730R are determined by the protrusion height of each microlens, the periodicity of the grating is broken, and the constructive interference and destructive interference caused by the overlap of the diffraction angles according to the diffraction orders of each region can be minimized. According to an embodiment of the present invention, the plurality of first microlenses 710 may all have different protrusion heights, the plurality of second microlenses 720 may all have different protrusion heights, and the plurality of third microlenses 730 may all have different protrusion heights.

[0264] In this case, 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 may have aspherical shapes, respectively. For example, the aspherical shapes of the first microlenses 710, the second microlenses 720, and the third microlenses 730 may be defined by image height, radius of curvature, and cone constant. For example, the aspherical shapes of the first microlenses 710, the second microlenses 720, and the third microlenses 730 may be defined by Mathematical Formula 14.

[0265] [Formula 14]

[0266]

[0267] Among them, Z represents the aspherical shape of the lens, h represents the image height, R represents the radius of curvature, and K represents the cone constant.

[0268] Since the microlens array is arranged in a two-dimensional manner, the aspherical shapes of the first microlens 710 , the second microlens 720 , and the third microlens 730 may be defined by Math Formula 15.

[0269] [Mathematical formula 15]

[0270]

[0271] Where x represents the image height on the X axis, y represents the image height on the Y axis, and R x Indicates the X-axis curvature radius, R y Indicates the Y-axis curvature radius, K x represents the X-axis cone constant, K y Represents the Y-axis cone constant.

[0272] Therefore, the FoI of the laser beam passing through the microlens array can be defined, and the light flux on a specific microlens can be concentratedly set not to exceed a predetermined value.

[0273] at the same time, Fig.22a is a plan view of a three-dimensional graph of a microlens array with uniform diameter, Figure 22b It is a stereogram of a three-dimensional diagram of a microlens array having a uniform diameter. As described above, a microlens array having a uniform diameter is formed with a sharp edge angle on the peripheral portion, and strong constructive interference occurs due to diffraction.

[0274] According to another embodiment of the present invention, the diffusion member includes a plurality of micro lenses having different diameters and different FoIs. Figures 1 to 21 Description: Repeated description of the same content.

[0275] Fig.23a is a plan view of a three-dimensional image of a microlens array according to another embodiment of the present invention, Figure 23b is a stereogram of a three-dimensional image of a microlens array according to yet another embodiment of the present invention.

[0276] refer to Fig.23a and Figure 23b , a microlens array 1700 according to yet another embodiment of the present invention includes a plurality of microlenses 1701 .

[0277] According to an embodiment of the present invention, 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses 1701 have different diameters. Here, the plurality of microlenses 1701 are arranged in a two-dimensional manner in a first direction and in a second direction perpendicular to the first direction. Here, the first direction may be referred to as the X direction, and the second direction may be referred to as the Y direction. Therefore, 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses 1701 may have different diameters in the first direction. Alternatively, 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses 1701 may have different diameters in the second direction.

[0278] According to an embodiment of the present invention, 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses 1701 have different FoIs. Here, FoI is defined by the aspheric shape, radius of curvature, and cone constant of each microlens. Therefore, at least 50%, preferably at least 60%, and more preferably 70% or more of the plurality of microlenses 1701 may have different aspheric shapes, radius of curvature, and cone constants. Here, the plurality of microlenses are arranged in a two-dimensional manner in the first direction and the second direction. Therefore, 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses may have different FoIs in the first direction. Alternatively, 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses may have different FoIs in the second direction. That is, 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses may have at least one of different aspheric shapes, radius of curvature, and cone constants in the first direction. Alternatively, 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, curvature radii, and conic constants in the second direction.

[0279] In this way, when 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses have different diameters and / or different FoIs, the diffraction phenomenon due to interference is minimized, the uniformity of the surface illumination pattern is increased, and the user's eyes are made safer.

[0280] According to an embodiment of the present invention, a plurality of microlenses having different diameters and / or different FoIs are disposed in the region a defined by Math.

[0281] [Formula 16]

[0282] a=2D tanθ

[0283] Where a represents 1 / e 2 The width of the area reached by the maximum light intensity is 1 / e times, D represents the distance from the light source 110 to the diffusion member 1700, and θ can be defined as 1 / e of the light source 110. 2 times the angle of maximum light intensity output.

[0284] In this regard, refer to Figure 3, the light source 110 and the microlens array 120 are arranged to be spaced apart from each other by a predetermined distance D. In addition, the light emitting element 112 outputs light at a predetermined angle θ. When a virtual normal perpendicular to the substrate 111 is drawn from the center of the light emitting element 112, an 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 specifications, and the divergence angle θ of the light output by the plurality of light emitting elements 112 may be the same.

[0285] For example, the light emitting element 112 may emit a predetermined amount of energy from -20 degrees to 20 degrees relative to the optical axis. However, it can be seen that the amount of energy is close to zero at an angle of -15 degrees, +15 degrees, below -15 degrees, or above 15 degrees. That is, most of the energy exists in a predetermined angle relative to the optical axis of the light emitting element. Therefore, it is inefficient to set all angles at which the amount of energy is not zero as the divergence angle of the light emitting element, while it is efficient to set the angle at which a predetermined amount or more of energy is emitted as the divergence angle of the light emitting element. Therefore, the divergence angle of the light source 110 may be set to 1 / e of the output light source 110. 2 The angle is times the maximum light intensity, and the area a defined by mathematical formula 16 can be called the effective light area.

[0286] Here, different diameters of multiple microlenses can be designed by random number generation. According to an embodiment of the present invention, the random number generation of the diameter of the microlens can be designed by using a Gaussian function distribution according to 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 the same number of times as the number of microlenses.

[0287] Similarly, different FoIs of multiple microlenses can be designed by random number generation. According to an embodiment of the present invention, the random number generation of the FoI of the microlens can be designed using a Gaussian function distribution according to 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 the same number of times as the number of microlenses.

[0288] Mathematical formula 17 represents a Gaussian function.

[0289] [Mathematical formula 17]

[0290]

[0291] Here, x represents the variable, μ represents the mean, and σ represents the standard deviation.

[0292] Fig.24a The Gaussian function distribution with an average diameter of 300.2 μm and a standard deviation of 10.94 μm in the X direction is shown. Figure 24bThe Gaussian function distribution with an average diameter of 301.2 μm and a standard deviation of 11.3 μm in the Y direction is shown. Fig.25a A Gaussian function distribution is shown with an average field of illumination (FoI) of 54.02 degrees in the X direction and a standard deviation of 0.9746 degrees, Fig.25b A Gaussian function distribution is shown with a mean field of illumination (FoI) of 62.06 degrees in the Y direction and a standard deviation of 0.9323 degrees.

[0293] At the same time, it may be difficult to Figures 24a to 25b Therefore, in the embodiment of the present invention, rejection sampling can be used to extract random numbers of diameters and / or FoIs of multiple microlenses.

[0294] For this purpose, an envelope function of the Gaussian function of Math 17 is defined. The envelope function has a form similar to that of the Gaussian function of Math 17, and for all possible values ​​of the variable, its value is larger than that of the Gaussian function of Math 17. Math 18 is an envelope function of the Gaussian function of Math 17.

[0295] [Mathematical formula 18]

[0296]

[0297] Here, x represents the variable, μ represents the mean, and σ represents the standard deviation.

[0298] According to an embodiment of the present invention, a random number is extracted from the envelope function of Mathematical Formula 18. Mathematical Formula 19 is a function for generating a random number from Mathematical Formula 18, which is an envelope function, using a continuous uniform distribution.

[0299] [Mathematical formula 19]

[0300]

[0301] The rejection sampling process according to an embodiment of the present invention can refer to Fig. 20 . According to an embodiment of the present invention, the Gaussian function of mathematical formula 17 is compared with the envelope function of mathematical formula 18 under the random number extracted from mathematical formula 19, and it can be determined whether to accept or reject the random number based on the result of the comparison. When the Gaussian function of mathematical formula 17 is compared with the envelope function of mathematical formula 18, the farther from the average value, the greater the difference, and the closer to the average value, the smaller the difference. Therefore, it is advantageous to accept a random number close to the average value.

[0302] At the same time, each microlens included in the plurality of microlenses may have an aspherical shape. The aspherical shape of each microlens may be defined by an image height, a radius of curvature, and a cone constant. For example, the aspherical shape of each microlens may be defined by Mathematical Formula 20.

[0303] [Mathematical formula 20]

[0304]

[0305] Among them, Z represents the aspherical shape of the lens, h represents the image height, R represents the radius of curvature, and K represents the cone constant.

[0306] Since the microlens array is arranged in a two-dimensional manner, the aspherical shape of each microlens can be defined by Mathematical Formula 21.

[0307] [Mathematical formula 21]

[0308]

[0309] Where x represents the image height on the X axis, y represents the image height on the Y axis, and R x Indicates the X-axis curvature radius, R y Indicates the Y-axis curvature radius, K x represents the X-axis cone constant, K y Represents the Y-axis cone constant.

[0310] The FoI of the laser beam passing through the microlens can be defined by the aspherical shape. Therefore, in an embodiment of the present invention, in order to design a plurality of microlenses with different FoIs, a random number of at least one of the aspherical shape, radius of curvature, and cone constant of the microlens can be generated. For example, a random number of at least one of the aspherical shape, radius of curvature, and cone constant of the microlens can be generated using a Gaussian function distribution according to a preset mean and standard deviation, and can be extracted by rejection sampling the same number of times as the number of microlenses. This can be done by referring to Mathematical Formulas 17 to 20 and Fig. 20 The rejection sampling is described to design a random number of at least one of the aspheric shape, the radius of curvature and the conic constant of the microlens.

[0311] Therefore, in the microlens assembly 1700 according to an embodiment of the present invention, at least one of the aspheric shape, the radius of curvature, and the cone constant of each of 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses may be different. Since the microlens assembly 1700 is arranged in a two-dimensional manner, at least one of the aspheric shape, the radius of curvature, and the cone constant of each of 50% or more, preferably 60% or more, and more preferably 70% or more of the plurality of microlenses may be different in the first direction, or at least one of the aspheric shape and the radius of curvature may be different in the second direction. In this case, at least one of the radius of curvature and the cone constant of each of at least some of the plurality of microlenses having the same radius of curvature and the cone constant in the first direction may be different in the second direction, or at least one of the radius of curvature and the cone constant of each of at least some of the plurality of microlenses having the same radius of curvature and the cone constant in the second direction may be different in the first direction.

[0312] Fig.26 shows the diameter and FoI of the microlens designed according to an embodiment of the present invention, Fig. 27 Shown according to Fig.26 The center position of the designed microlens array, Fig.28a is based on Fig.26 The FoI diagram of the design in the X direction, Fig.28b is based on Fig.26 FoI diagram of the design in the Y direction, Fig.29 is based on Fig.29 Glowing image for your design.

[0313] refer to Fig.26 , X spacing represents the diameter in the X direction, Y spacing represents the diameter in the Y direction, X_k represents the cone constant in the X direction, X_R represents the curvature radius in the X direction, Y_k represents the cone constant in the Y direction, Y_R represents the curvature radius in the Y direction, X FoI_simul. represents the FoI in the X direction, and Y FoI_simul. represents the FoI in the Y direction. The diameter and FoI of the microlens are the results of the random number generation method according to the embodiment of the present invention designed in the following manner: the average diameter of the plurality of microlenses in the X direction is set to 300.2 μm, the standard deviation is set to 10.94 μm, the average diameter in the Y direction is set to 301.2 μm, the standard deviation is set to 11.3 μm, the average FoI in the X direction is set to 54.02 degrees, the standard deviation is set to 0.9746 degrees, the average FoI in the Y direction is set to 62.06 degrees, the standard deviation is set to 0.9323 degrees, and the number of samples is set to 36. Therefore, it can be seen that the diameters of the 36 microlenses are different, and the FoIs are different.

[0314] refer to Fig. 27 , the uniform position in the grid of the 6*6 matrix is ​​the center position of each grid, and the random position is based on Fig.26 Therefore, it can be seen that according to the design of Fig.26 The center positions of the multiple microlenses generated by the design are randomly arranged.

[0315] refer to Fig.28a and Fig.28b , it can be seen that each microlens (e.g., MLA7, MLA9, MLA29, and MLA31) has its own FoI, but the overall FoI of the random MLA (MLA1 to MLA36) converges to the pre-designed average FoI.

[0316] refer to Fig.29 , it can be seen that the microlens array including MLA1 to MLA36 can more effectively suppress the diffraction phenomenon and make the surface illumination pattern uniform than the microlens array including 36 MLA7s, the microlens array including 36 MLA9s, the microlens array including 36 MLA29s, and the microlens array including 36 MLA31s.

[0317] Reference again Fig.23a and Figure 23b , the diffusion member 1700 according to an embodiment of the present invention includes a microlens array including a plurality of microlenses, and 50% or more of the microlenses in the microlens array are microlenses having different FoIs.

[0318] In this case, the microlens array includes a plurality of microlenses arranged in an N*M matrix. Here, N and M are both integers greater than or equal to 3, and may be the same or different. According to an embodiment of the present invention, a plurality of microlenses arranged in at least a 3*3 matrix have different FoIs. As described above, since the FoI is defined by an aspherical shape, a radius of curvature, and a cone constant, at least one of the aspherical shape, the radius of curvature, and the cone constant of each of the plurality of microlenses arranged in a 3*3 matrix may be different.

[0319] According to an embodiment of the present invention, 50% or more, preferably 60% or more, and more preferably 70% or more of the microlenses with different diameters and / or different FoIs among the plurality of microlenses may be distributed and dispersed between a plurality of other microlenses with the same diameter and / or the same FoI. Alternatively, 50% or more, preferably 60% or more, and more preferably 70% or more of the microlenses with different diameters and / or different FoIs among the plurality of microlenses may be disposed adjacent to each other between a plurality of other microlenses with the same diameter and / or the same FoI.

[0320] Fig.30 FIG. 1 is a plan view of a microlens array according to another embodiment of the present invention. Figures 1 to 29 Description: Repeated description of the same content.

[0321] refer to Fig.30 According to another embodiment of the present invention, the microlens array 1700 may 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 .

[0322] 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 may have different FoIs. In this case, the different FoIs of the plurality of microlenses included in the first region 1700R1 may range from 0.9 times to 1.1 times the average FoI. In this case, the different FoIs may refer to Mathematical Formulas 17 to 19 and Fig. 20 The description is designed by random number generation. The plurality of microlenses included in the first region 1700R1 may have different FoIs in the first direction, or different FoIs in the second direction. That is, the plurality of microlenses included in the first region 1700R1 may have at least one of different aspherical shapes, curvature radii, and conic constants in the first direction, or at least one of different aspherical shapes, curvature radii, and conic constants in the second direction.

[0323] In this case, the area of ​​the first region 1700R1 may range from 50% to 70%, preferably from 55% to 65%, of the total area of ​​the microlens array 1700. The first region 1700R1 is disposed at the position indicated by reference to Mathematical Formulas 16 and 170 Figure 3 The description is in area a defined by .

[0324] In addition, the second region 1700R2 includes a plurality of micro lenses, and the plurality of micro lenses included in the second region 1700R2 may have the same FoI.

[0325] Therefore, the optical signal passing through the microlens array 1700 can be diffused and reaches the target area including the object. Therefore, in the main part of the target area including the object, the diffraction phenomenon due to interference can be reduced, and the optical signal with a uniform surface pattern can reach, and the design complexity of the microlens array 1700 can be reduced.

[0326] Here, the plurality of microlenses included in the first region 1700R1 may have different diameters. In this case, the different diameters of the plurality of microlenses included in the first region 1700R1 may refer to Mathematical Formulas 17 to 19 and Fig. 20 The description of is designed by random number generation. Therefore, the diffraction phenomenon due to interference can be reduced and a uniform surface pattern can be achieved.

[0327] Fig.31 FIG. 1 is a plan view of a microlens array according to another embodiment of the present invention. Figures 1 to 30 Duplicate descriptions of the same content.

[0328] refer to Fig.31 , a microlens array 1700 according to still another embodiment of the present invention includes a first region 1700RA and a second region 1700RB disposed on a side surface of the first region 1700RA.

[0329] The first region 1700RA and the second region 1700RB each include a plurality of microlenses, and the plurality of microlenses included in the first region 1700RA may have different FoIs, and the plurality of microlenses included in the second region 1700RB may have different FoIs. In this case, different FoIs may refer to Mathematical Formulas 17 to 19 and Fig. 20 The description is designed by random number generation. The multiple microlenses included in the first area 1700RA may have different FoIs in the first direction, or different FoIs in the second direction. That is, the multiple microlenses included in the first area 1700RA may have different aspheric shapes, curvature radii, and at least one of cone constants in the first direction, or different aspheric shapes, curvature radii, and cone constants in the second direction. The multiple microlenses included in the second area 1700RB may have different FoIs in the first direction, or different FoIs in the second direction. That is, the multiple microlenses included in the first area 1700RB may have different aspheric shapes, curvature radii, and cone constants in the first direction, or different aspheric shapes, curvature radii, and cone constants in the second direction.

[0330] In this case, an average FoI of the plurality of microlenses included in the first region 1700RA may be the same as an average FoI of the plurality of microlenses included in the second region 1700RB. Here, the same average FoI may include an error range of ±5%.

[0331] According to an embodiment of the present invention, the light source 110 may be a VCSEL, and the VCSEL may be driven in different regions. For example, the light source 110 may be divided into a first VCSEL region and a second VCSEL region, and the first VCSEL region may be driven during a first time region, and the second VCSEL region may be driven during a second time region. The average FoI of the plurality of microlenses included in the first region 1700RA of the microlens array 1700 may be 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 may be set at a position corresponding to the first VCSEL region, and the second region 1700RB of the microlens array 1700 may be set at a position corresponding to the second VCSEL region. Therefore, the diffraction phenomenon caused by interference during the entire time region can be reduced, and a uniform surface pattern can be achieved.

[0332] Here, the plurality of microlenses included in the first region 1700RA may have different diameters. In this case, the different diameters of the plurality of microlenses included in the first region 1700RA may refer to Mathematical Formulas 17 to 19 and Fig. 20 The description is designed by random number generation. In addition, the plurality of microlenses included in the second region 1700RB may have different diameters. In this case, the different diameters of the plurality of microlenses included in the second region 1700RB may refer to Mathematical Formulas 17 to 19 and Fig. 20 The description of is designed by random number generation. Therefore, the diffraction phenomenon due to interference can be reduced and a uniform surface pattern can be achieved.

[0333] According to still another embodiment of the present invention, the microlens array may be divided into a plurality of regions and may include microlenses having different average diameters for each region.

[0334] Fig.32 is a plan view of a microlens array according to yet another embodiment of the present invention, Fig.33 is a view for describing the diameters of microlenses forming a microlens array according to still another embodiment of the present invention, Fig.34 yes Fig.32 An example of the first region 1710R.

[0335] refer to Figure 32 to Figure 34According to another embodiment of the present invention, a microlens array 1700 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, in the description of the microlens array 1700, the reference numerals 1710 and the first microlenses 1710 are omitted. Figures 1 to 31 Repeated description of the same content as described. Here, the first area 1710R to the third area 1730R including the first microlens to the third microlens having the first average diameter to the third average diameter is mainly described, but this is for the convenience of description and the present invention is not limited to this. An embodiment of the present invention may be a microlens array including only the first area 1710R and the second area 1720R, or may be extended to a fourth area surrounding the third area 1730R and including a plurality of fourth microlenses having a fourth average diameter, a fifth area surrounding the fourth area and including a plurality of fifth microlenses having a fifth average diameter, and the like.

[0336] Here, the first region 1710R may be a region including the center of the microlens array 1700 .

[0337] 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.

[0338] In addition, multiple first microlenses 1710 are arranged in the first area 1710R along a second direction perpendicular to the first direction and intersecting the optical axis direction, multiple second microlenses 1720 are arranged in the second area 1720R along the second direction, and multiple third microlenses 1730 are arranged in the third area 1730R along the second direction.

[0339] In this case, the plurality of first microlenses 1710 disposed in the outermost columns and the outermost rows of the first region 1710R may be disposed adjacent to the plurality of second microlenses 1720 disposed in the second region 1720R, and the plurality of second microlenses 1720 disposed in the second region 1720R may be disposed adjacent to the plurality of third microlenses 1730 disposed in the third region 1730R. The plurality of second microlenses 1720 may be disposed in a row to surround the outermost portion of the first region 1710R, and the plurality of third microlenses 1730 may be disposed in a row to surround the second region 1720R. Therefore, the first microlenses 1710 may be disposed 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 disposed, and the third microlenses 1730 may be disposed on the other side surface of each second microlens 1720. That is, the second microlenses 1720 may not be disposed 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 disposed. Likewise, the third microlenses 1730 may not be arranged on both side surfaces of each of the third microlenses 1730 in a direction perpendicular to the arrangement direction of the plurality of third microlenses 1730. The distance from the center of the diffusion member 1700 (i.e., 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.

[0340] Here, the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3 may be used interchangeably with the first average spacing AP1, the second average spacing AP2, and the third average spacing AP3, respectively. Here, the diameter may refer to the length of the microlens in the first direction or the second direction. However, the diameter may refer to the length of the microlens in a direction other than the first direction and the second direction. For example, the diameter may refer to the length of the microlens in the first direction, the second direction, or the third direction (i.e., the optical axis direction).

[0341] In this case, the first average diameter AP1, the second average diameter AP2, and the third average diameter AP3 may be different. According to an embodiment of the present invention, the second average diameter AP2 may be greater than the first average diameter AP1, and the third average diameter AP3 may be greater than the second average diameter AP2. According to an embodiment of the present invention, the second average diameter AP2 may be more than 1.1 times the first average diameter AP1, and the third average diameter AP3 may be more than 1.1 times 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 greater than the ratio of the third average diameter AP3 to the second average diameter AP2. Therefore, the energy of the output light can be dispersed, thereby improving the safety of the user's eyes and preventing uniformity degradation due to interference.

[0342] According to an embodiment of the present invention, the plurality of first microlenses 1710 in the first region 1710R may have different FoIs, the plurality of second microlenses 1720 in the second region 1720R may have different FoIs, and the plurality of third microlenses 1730 in the third region 1730R may have different FoIs. That is, the plurality of first microlenses 1710 in the first region 1710R may have at least one of different aspherical shapes, curvature radii, and conic constants, the plurality of second microlenses 1720 in the second region 1720R may have at least one of different aspherical shapes, curvature radii, and conic constants, and the plurality of third microlenses 1730 in the third region 1730R may have at least one of different aspherical shapes, curvature radii, and conic constants.

[0343] As described above, by referring to Mathematical Formulas 17 to 19 and Fig. 20 The random number generation described above is used to design different FoIs for each region.

[0344] In this case, the plurality of first microlenses 1710 in the first region 1710R may have different FoIs in the first direction, the plurality of second microlenses 1720 in the second region 1720R may have different FoIs in the first direction, and the plurality of third microlenses 1730 in the third region 1730R may have different FoIs in the first direction. Alternatively, the plurality of first microlenses 1710 in the first region 1710R may have different FoIs in the second direction, the plurality of second microlenses 1720 in the second region 1720R may have different FoIs in the second direction, and the plurality of third microlenses 1730 in the third region 1730R may have different FoIs in the second direction. That is, the plurality of first microlenses 1710 in the first region 1710R may have at least one of different aspheric shapes, radii of curvature, and cone constants in the first direction, the plurality of second microlenses 1720 in the second region 1720R may have at least one of different aspheric shapes, radii of curvature, and cone constants in the first direction, and the plurality of third microlenses 1730 in the third region 1730R may have at least one of different aspheric shapes, radii of curvature, and cone constants in the first direction. Alternatively, the plurality of first microlenses 1710 in the first region 1710R may have at least one of different aspheric shapes, radii of curvature, and cone constants in the second direction, the plurality of second microlenses 1720 in the second region 1720R may have at least one of different aspheric shapes, radii of curvature, and cone constants in the second direction, and the plurality of third microlenses 1730 in the third region 1730R may have at least one of different aspheric shapes, radii of curvature, and cone constants in the second direction.

[0345] In this case, 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. Here, the same average FoI may include an error range of ±5%, so even if each microlens included in the microlens array 1700 has a different FoI, the surface illumination pattern output by the microlens array 1700 may converge to the average FoI, thereby obtaining a uniform surface illumination pattern.

[0346] 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 may have different diameters. The plurality of second microlenses 1720 having the second average diameter AP2 in the second region 1720R may have different diameters. The plurality of third microlenses 1730 having the third average diameter AP3 in the third region 1730R may have different diameters.

[0347] To this end, 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 may be designed by random number generation, respectively. When the plurality of microlenses included in each region have different diameters, constructive interference and destructive interference due to overlap of diffraction angles according to diffraction orders can be minimized. The random number generation of the diameters of the microlenses may refer to Mathematical Formulas 17 to 19 and Fig. 20 .

[0348] Meanwhile, according to an embodiment of the present invention, the number and average diameter of microlenses included in at least one of the first to third regions 1710R, 1720R, and 1730R have a correlation with the average diameter of microlenses included in another region surrounding at least one of the first to third regions 1710R, 1720R, and 1730R. The number of region-specific microlenses according to an embodiment of the present invention may refer to Mathematical Formula 13.

[0349] According to an embodiment of the present invention, the average diameter of the microlens may vary according to 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 microlens may increase. Therefore, the concentration of the luminous flux of a specific microlens may be reduced, thereby making the user's eyes safe.

[0350] Fig.35 is an exploded view of a camera module according to an embodiment of the present invention.

[0351] The camera module may include a light emitting unit and a light receiving unit. However, since components such as the base 10, the bracket 30, and the shielding cover 50 are formed integrally and used in common for the light emitting unit and the light receiving unit, it may be difficult to distinguish the light emitting unit from the light receiving unit. In this case, each of the above components can be understood as a component of each of the light emitting unit and the light receiving unit. However, as a modified example, the common configuration of the base 10, the bracket 30, and the shielding cover 50 may be provided separately to the light emitting unit and the light receiving unit.

[0352] The light emitting unit may include a substrate 10, a light source 20, a bracket 30, a diffusion member 41, a diffusion ring 42 and a shield 50. The light receiving unit may include a substrate 10, a sensor 60, a filter 80, a bracket 30, a lens 70, a barrel 71 and a shield 50.

[0353] The substrate 10 may include a PCB. The substrate 10 may be connected to a connector via a flexible PCB (FPCB) 91. The substrate 10 and the FPCB 91 may be formed as a rigid FPCB (RFPCB). The light source 20 and the sensor 60 may be disposed on the substrate 10. The substrate 10 may be disposed below the bracket 30. The substrate 10 may include a terminal. The terminal of the substrate 10 may be connected to a connection portion of the shielding case 50. The terminal of the substrate 10 may include a plurality of terminals. The terminal of the substrate 10 may include two terminals.

[0354] The light source 20 may be disposed on the substrate 10. The light source 20 may be disposed in contact with the substrate 10. The light source 20 may be disposed above the substrate 10. The light source 20 may be disposed on the substrate 10. The light source 20 may correspond to the light source 110.

[0355] The bracket 30 may be disposed on the substrate 10. The bracket 30 may be disposed in contact with the substrate 10. The bracket 30 may be disposed above the substrate 10. The bracket 30 may be disposed on the substrate 10. The bracket 30 may be fixed to the substrate 10 by an adhesive. The bracket 30 may accommodate the light source 20, the diffusion module 40, the sensor 60, and the filter 80 therein. The bracket 30 may be a plastic injection molded product. The bracket 30 may be formed by injection molding.

[0356] The diffusion module 40 may include a diffusion member 41 and a diffusion ring 42. The diffusion module 40 may be integrally formed as in the modified example, but in the present embodiment, the diffusion module 40 may be manufactured separately as the diffusion member 41 and the diffusion ring 42 to improve moldability during injection molding. The diffusion member 41 and the diffusion ring 42 may be separate.

[0357] The diffusion member 41 may be a diffusion lens. The diffusion member 41 may correspond to the diffusion member 120 and the diffusion member 400 described above. The diffusion member 41 may be disposed in the bracket 30. The diffusion member 41 may be coupled to the bracket 30. The diffusion member 41 may be fixed to the bracket 30. The diffusion member 41 may be disposed on the optical path of the light emitted from the light source 20. The diffusion member 41 may be disposed on the light source 20. The diffusion member 41 may be disposed above the light source 20. The diffusion member 41 may be a plastic injection molded product. The diffusion member 41 may be formed by plastic injection molding. The height of the upper end of the diffusion member 41 may correspond to the height of the upper end of the lens 70. The diffusion member 41 may be inserted and coupled to the bracket 30 upward in the vertical direction. In this case, upward may be a direction from the lower portion of the bracket 30 to the upper portion of the bracket 30. A portion of the diffusion member 41 may overlap the bracket 30 upward.

[0358] The diffusion ring 42 may be disposed in the bracket 30. The diffusion ring 42 may be fixed to the bracket 30. The diffusion ring 42 may be coupled to the bracket 30. The diffusion ring 42 may be disposed below the diffusion member 41. The diffusion ring 42 may support the diffusion member 41. The diffusion ring 42 may contact the diffusion member 41. The diffusion ring 42 may be a plastic injection molded product. The diffusion ring 42 may be formed by plastic injection molding.

[0359] The shielding cover 50 may cover the main body of the bracket 30. The shielding cover 50 may include a cover. The shielding cover 50 may include a cover. The shielding cover 50 may be a non-magnetic. The shielding cover 50 may be formed of a metal material. The shielding cover 50 may be formed of a metal plate. The shielding cover 50 may be electrically connected to the substrate 10. The shielding cover 50 may be connected to the substrate 10 via solder balls. Therefore, the shielding cover 50 may be grounded. The shielding cover 50 may block electromagnetic interference (EMI). In this case, the shielding cover 500 may be referred to as an "EMI shielding cover". In the present embodiment, since a high voltage is used inside the optical device, electromagnetic interference noise may increase, and the shielding cover 50 may block electromagnetic interference noise.

[0360] The sensor 60 may be disposed on the substrate 10. The sensor 60 may be disposed on the other side of the partition wall of the bracket 30 on the substrate 10. That is, the sensor 60 may be disposed on the side opposite to the light source 20 relative to the partition wall of the bracket 30. The sensor 60 may detect infrared rays. The sensor 60 may detect light of a specific wavelength in the infrared rays. The sensor 60 may detect light passing through the filter 80. The sensor 60 may detect light within the wavelength band of the light source 20. Therefore, the sensor 60 may detect light emitted from the light source 20 and reflected in the object to sense three-dimensional image information of the object. The effective sensing area of ​​the sensor 60 is set to correspond to the diffusion member 41, but the sensor 60 may be set to be completely biased toward the partition wall. The circuit pattern of the sensor 60, etc. may be set in the portion where the sensor 60 is biased toward the partition wall.

[0361] The lens 70 may be fixed in the lens barrel 71. The lens 70 may be a plastic injection molded product. The lens 70 may be formed by plastic injection molding. The lens 70 may include a plurality of lenses.

[0362] The optical filter 80 may be disposed between the lens 70 and the sensor 60. The optical filter 80 may be a bandpass filter that allows light of a specific wavelength to pass through. The optical filter 80 may allow infrared rays to pass through. The optical filter 80 may allow light of a specific wavelength in infrared rays to pass through. The optical filter 80 may allow light of a wavelength band of light emitted by the light source 20 to pass through. The optical filter 80 may block visible light. The optical filter 80 may be coupled to the bracket 30. A groove having a size corresponding to that of the optical filter 80 may be formed in the bracket 30, and the optical filter 80 may be inserted into the groove and fixed with an adhesive. An adhesive injection groove may be formed together in the groove of the bracket 30, and an adhesive is injected between the optical filter 80 and the bracket 30 through the adhesive injection groove. The optical filter 80 may be disposed at a position lower than that of the diffusion ring 42.

[0363] Although the above mainly describes a camera device that uses a TOF method to extract depth information, embodiments of the present invention are not limited thereto. A camera device according to an embodiment of the present invention may be a camera device that uses a structured light method to extract depth information. That is, a camera device according to an embodiment of the present invention may use structured light having a predetermined pattern as an output light signal, and use the parallax of the structured light to generate depth information. In addition, a camera device according to an embodiment of the present invention may be a camera device mounted on a vehicle for measuring the distance between the vehicle and an object. That is, a camera device according to an embodiment of the present invention may be a light detection and ranging (LiDAR) camera.

[0364] Although the above mainly describes the embodiments, these are only illustrative and do not limit the present invention, and those skilled in the art to which the present invention belongs can know that various modifications and applications not illustrated above are also possible without departing from the essential features of the embodiments. For example, each component specifically shown in the embodiments can be implemented by modification. In addition, the differences related to these modifications and applications should be understood to be included in the scope of the present invention defined in the appended claims.

Claims

1. A camera device, comprising: a light emitting unit configured to irradiate a light signal toward an object; a light receiving unit including an image sensor and configured to receive the light signal reflected from the object; as well as a depth information generating unit configured to generate depth information of the object using the light signal received by the light receiving unit, Wherein, the light emitting unit comprises: Light source; and A microlens array is disposed on the light source, The microlens array comprises: 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, and The number and diameter of the microlenses included in at least one of the first to third regions have a correlated relationship 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 camera device according to claim 2, wherein: The first area includes x1 first micro lenses arranged along a first direction, The second area includes x2 second micro lenses arranged along the first direction, The third region includes x3 third micro lenses arranged along the first direction, The product of the first diameter and the x1 is equal to the product of the second diameter and a number that is 1 less than the x1, and The product of the second diameter and the x2 is equal to the product of the third diameter and a number that is 1 less than the x2.

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

5. The camera device according to claim 1, wherein: The plurality of first micro lenses, the plurality of second micro lenses, and the plurality of third micro lenses 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 heights of the plurality of third microlenses are different from each other.

6. The camera device according to claim 1, wherein: Each of the plurality of first microlenses, the plurality of second microlenses, and the plurality of third microlenses has an aspherical shape, and An 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 cone constant.

7. The camera device according to claim 6, wherein: 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 1: Where x represents the image height on the X axis, y represents the image height on the Y axis, and R x Indicates the X-axis curvature radius, R y Indicates the Y-axis curvature radius, K x represents the X-axis cone constant, K y Represents the Y-axis cone constant.

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

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

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

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