Light guidance apparatus and camera apparatus comprising same

Abstract

Disclosed is a camera apparatus according to an embodiment of the present invention comprising: a light source unit emitting light; a light guidance apparatus for guiding the light from the light source unit to irradiate an object with the light, and guiding the light reflected from the object; and a light-receiving unit for receiving the guided light reflected from the object, wherein the light guidance apparatus comprises a substrate, and on the substrate, an input diffraction element, an input-and-output diffraction element, and an output diffraction element, and the count of total reflection of the light diffracted by the input-and-output diffraction element is the same the count by the input diffraction element.

Description

Light guide device and camera device including the same

[0001] The embodiment relates to a light guide device and a camera device including the same.

[0002] Currently, traffic accidents caused by drivers are increasing significantly along with the increase in the number of vehicles, and there is a problem in that the incidence rate of these accidents increases significantly depending on the driver's physical condition.

[0003] In particular, accidents caused by driver inattention, such as the use of smartphones while driving, have been increasing significantly recently. Due to the rising problem of traffic accidents resulting from such driver inattention or drowsy driving, automobile manufacturers are now equipping vehicles with Driver Monitoring Systems (DMS) that monitor the driver's concentration and physical condition while driving.

[0004] While DMS was generally implemented at the level of simply predicting the driver's condition based on the driver's steering state or the driving time and raising the driver's awareness through warning sounds or messages, recently, with the development of Advanced Driver Assistance Systems (ADAS) that provide various functions to directly assist the driver, such as Adaptive Cruise Control (ACC), which drives while maintaining a distance from the vehicle in front at a speed set by the driver, and Lane Keeping Assist System (LKAS), which recognizes lanes using a camera to maintain the lane, various methods are being implemented to more actively identify the driver's state of concentration or physical condition such as drowsiness. These methods include monitoring the driver's physical movements through video captured by a camera or monitoring the movement of the driver's eyelids to determine whether the driver is drowsy or focused on driving, and generating steering wheel vibrations or warning sounds to the driver or reducing the vehicle's speed to below a certain level to avoid danger.

[0005] Meanwhile, as the autonomous driving performance of automobiles advances, drivers no longer necessarily need to hold the steering wheel, and as hands-off situations occur frequently, there is a demand for a driver monitoring system equipped with a hands-off monitoring function. Consequently, there is a need for an advanced DMS capable of determining the driver's state of concentration or drowsiness based on various driver movements resulting from hands-off.

[0006] However, as drivers and others do not prefer to be filmed or monitored, there is an increasing need for technology that prevents drivers from being aware of such surveillance.

[0007] The embodiment provides a light guide device and a camera device in which image generation of a passenger, etc., within a vehicle is more easily implemented, and double images are eliminated by adjusting the length of a diffraction element, thereby improving image quality.

[0008] In addition, the embodiment can provide a light guide device and a camera device with improved optical quality by adjusting the position of the diffraction element to improve light intensity uniformity.

[0009] In addition, the embodiment can provide a light guide device and a camera device capable of providing high-precision images without being affected by external environments, by providing incident light to an input diffraction element at different incident angles depending on the wavelength.

[0010] In addition, the embodiment can provide an easy-to-manufacture and miniaturized light guide device and camera device by setting the grating vector of each diffraction element to be the same.

[0011] In addition, a light guide device and a camera device that minimize light interference or reflection through a prevention unit, etc., can be provided.

[0012] The problems intended to be solved in the embodiments are not limited thereto, and may also include objectives or effects that can be identified from the means of solving the problems or the embodiments described below.

[0013] A camera device according to an embodiment comprises: a light source unit that irradiates light; a light guide device that guides light from the light source unit to irradiate an object and guides light reflected from the object; and a light receiving unit that receives light reflected from the object and guided. The light guide device comprises: a substrate; an input diffraction element disposed on the substrate; an input / output diffraction element disposed on the substrate; and an output diffraction element disposed on the substrate. The light diffracted by the input / output diffraction element has the same number of total reflections from the input diffraction element.

[0014] The light diffracted by the input diffraction element and guided within the substrate may have a wavelength ranging from a minimum wavelength, which is the first wavelength, to a maximum wavelength, which is the second wavelength.

[0015] The length in the first direction of the input diffraction element may be smaller than the horizontal distance traveled by the light of the first wavelength being reflected twice within the substrate.

[0016] The length in the first direction of the input diffraction element may be smaller than the horizontal distance traveled by the light of the second wavelength being reflected twice.

[0017] The light of the first wavelength is incident on the input diffraction element at a first diffraction angle, and the light of the second wavelength is incident on the input diffraction element at a second diffraction angle, and the first diffraction angle may be larger than the second diffraction angle.

[0018] The length in the first direction of the input diffraction element can satisfy the following Equations 1 and 2.

[0019] [Equation 1]

[0020]

[0021] [Equation 2]

[0022]

[0023] (Here, a is the length in the first direction of the input diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle)

[0024] The light diffracted by the above input diffraction element may have a different diffraction angle corresponding to the wavelength.

[0025] The light diffracted by the input / output diffraction element has been totally reflected from the input diffraction element n times, and at least a portion of the light that has been totally reflected from the input diffraction element n times may not be diffracted by the input / output diffraction element.

[0026] The light diffracted by the above input / output diffraction element can satisfy Equation 3 below.

[0027] [Equation 3]

[0028] , n is an integer greater than 0

[0029] (Here, a is the length in the first direction of the input diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle)

[0030] The length in the first direction of the input / output diffraction element may be greater than the thickness of the substrate and smaller than the length in the first direction of the input diffraction element.

[0031] The above input / output diffraction element may be spaced apart from the above input diffraction element in a first direction.

[0032] The distance in the first direction between one end of the input / output diffraction element and one end of the input diffraction element may be greater than the horizontal distance traveled by the light of the first wavelength reflecting once within the substrate.

[0033] The distance in the first direction between one end of the input / output diffraction element and one end of the input diffraction element may be smaller than the sum of the distance traveled by the light of the second wavelength reflected once within the substrate and the length in the first direction of the input diffraction element.

[0034] The separation distance in the first direction between one end of the input / output diffraction element and one end of the input diffraction element can satisfy the following Equation 4.

[0035] [Equation 4]

[0036]

[0037] (Gap is the distance between one end of the input / output diffraction element and one end of the input diffraction element, a is the length in the first direction of the input diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle)

[0038] If the length in the first direction of the input diffraction element is smaller than the thickness of the substrate, the following Equation 5 can be satisfied.

[0039] [Equation 5]

[0040]

[0041] (Here, b is the length in the first direction of the input / output diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle)

[0042] If the length in the first direction of the input diffraction element is greater than the thickness of the substrate, the following Equation 6 can be satisfied.

[0043] [Equation 6]

[0044]

[0045] (Here, b is the length in the first direction of the input / output diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle)

[0046] The substrate includes a first surface and a second surface corresponding to the first surface, and the input diffraction element, the input / output diffraction element, and the output diffraction element may be disposed on either the first surface or the second surface.

[0047] At least a portion of the input / output diffraction element may overlap with the input diffraction element in the thickness direction.

[0048] The above input diffraction element can diffract light irradiated from the light source and guide it into the substrate.

[0049] The input / output diffraction element can diffract light guided by the input diffraction element toward an object, diffract light reflected from the object toward the substrate, and guide light reflected from the object toward the substrate. The output diffraction element can diffract light reflected from the object toward the substrate and guide it toward the light receiving unit.

[0050] The embodiment implements an optical guide device and a camera device in which image generation of a passenger, etc., within a vehicle is more easily implemented, and double images are eliminated by adjusting the length of a diffraction element, thereby improving image quality.

[0051] In addition, the embodiment can implement a light guide device and a camera device with improved optical quality by improving light intensity uniformity through adjusting the position of the diffraction element.

[0052] In addition, the embodiment can implement a light guide device and a camera device that can provide high-precision images without being affected by external environments, by providing incident light to an input diffraction element at different incident angles depending on the wavelength.

[0053] In addition, the embodiment enables the implementation of an easy-to-manufacture and miniaturized light guide device and camera device by setting the grating vector of each diffraction element to be the same.

[0054] In addition, light guide devices and camera devices that minimize light interference or reflection can be implemented through the prevention unit, etc.

[0055] The various and beneficial advantages and effects of the present invention are not limited to those described above and may be more easily understood in the process of explaining specific embodiments of the present invention.

[0056] FIG. 1 is a conceptual diagram of a vehicle including a camera device according to an embodiment of the present invention, and

[0057] FIG. 2 is a drawing illustrating the operation according to a camera device according to an embodiment of the present invention, and

[0058] FIG. 3 is a flowchart illustrating the operation of a camera device according to an embodiment, and

[0059] FIG. 4 is a block diagram of a camera device according to an embodiment, and

[0060] FIG. 5 is a drawing showing the configuration of a camera device according to an embodiment, and

[0061] FIG. 6 is a diagram illustrating the operation of a camera device according to an embodiment, and

[0062] FIG. 7 is a perspective view of a light guide device in a camera device according to an embodiment, and

[0063] FIG. 8 is a cross-sectional view of an optical guide device viewed by cutting along II' in FIG. 7, and

[0064] Fig. 9 is a partial enlarged view of Fig. 8, and

[0065] FIGS. 10 and 11 are drawings illustrating the effect of a light guide device in a camera device according to an embodiment, and

[0066] FIG. 12 is a cross-sectional view of another example of a light guide device in a camera device according to an embodiment, and

[0067] FIG. 13 is a cross-sectional view of another example of a light guide device in a camera device according to an embodiment.

[0068] The present invention is susceptible to various modifications and may have various embodiments, and specific embodiments are illustrated and described in the drawings. However, this does not specify the present invention.

[0069] It should be understood that the embodiments are not intended to be limited and include all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0070] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0071] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0072] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0073] Additionally, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as “and at least one of B and C (or more than one),” it may include one or more of all combinations that can be combined with A, B, and C.

[0074] Terms including ordinal numbers, such as second, first, etc., may be used to describe various components, but the components are not limited by the terms. The terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be named the first component, and similarly, the first component may be named the second component. The term "and / or" includes a combination of multiple related described items or any of the multiple related described items. Such terms are intended only to distinguish the component from other components and are not limited by the essence, order, sequence, etc. of the component.

[0075] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0076] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0077] Furthermore, when described as being formed or placed "above or below" each component, "above or below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0078] In addition, the expression that configuration A is positioned between configuration B and configuration C must include the meaning that configuration A is positioned such that at least a portion of it overlaps with configurations B and C in the horizontal and / or vertical directions.

[0079] Expressions referring to directions include horizontal and vertical directions, and the horizontal direction includes a first horizontal direction and a second horizontal direction perpendicular to the first horizontal direction. These are referred to as the first horizontal direction (X-axis), the second horizontal direction (Y-axis), and the vertical direction (Z-axis) according to the Cartesian coordinate system, and the meaning of being superimposed along the horizontal direction must include the meaning of being superimposed along the first horizontal direction and / or superimposed along the second horizontal direction.

[0080] Furthermore, the statement that Configuration A is exposed from Configuration B should be understood as meaning that Configuration A is exposed from Configuration B, not that Configuration A is exposed from the entire product. In other words, when Configuration A is stated to be exposed from Configuration B, it should be understood to mean that Configuration A is covered by at least a portion of Configuration C.

[0081] Furthermore, when it is stated that Component A 'contacts' Component B, this may include not only cases where the component 'contacts' the other component directly, but also cases where it 'contacts' due to another component located between the component and the other component. Therefore, if Component A is to be understood only as 'directly contacting' Component B, it is described as 'directly contacting'.

[0082] In addition, when it is stated that configuration A is 'covered' by configuration B, it should be understood that configuration A is covered by configuration B, and that the part intended for the function and purpose to be resolved is covered, and unless there are special circumstances, it should not be understood that the entire configuration A is covered by configuration B.

[0083] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0084] FIG. 1 is a conceptual diagram of a vehicle including a camera device according to an embodiment of the present invention, FIG. 2 is a diagram explaining the operation according to a camera device according to an embodiment of the present invention, and FIG. 3 is a flowchart explaining the operation of a camera device according to an embodiment.

[0085] Referring to FIG. 1, a vehicle system (or environment) according to an embodiment may include a vehicle (1), a person (e.g., passenger, driver), and an electronic device (CU). In the following description, the electronic device (CU) is described as a device separately provided within the vehicle (1), but the present invention is not limited thereto. For example, the electronic device (CU) may be implemented as a part of the vehicle (1).

[0086] The vehicle (1) may include a vehicle body and various devices for moving the vehicle body (e.g., wheels, a drive unit for driving the wheels, a starter unit for starting the drive unit, an engine that generates power and transmits the generated power to the drive unit, a steering unit that controls the direction of the vehicle, an acceleration unit that controls the speed of the vehicle, etc.). In addition, the vehicle (1) may include various electrical systems. For example, the electrical systems may include an engine control unit that controls the engine, a temperature control unit that controls the temperature inside the vehicle, a light control unit that controls the lights according to external conditions, etc.

[0087] In particular, the vehicle (1) may include a communication interface capable of communicating with an electronic device (CU), and may include an additional processor that performs a preset function based on the analysis of data transmitted through the communication interface and the results of the analysis.

[0088] The processor may be implemented, for example, as the engine control unit or motor control unit described above. The communication interface may support at least one of various communication methods, such as CAN communication that supports data transmission and reception within the vehicle (1) or wired communication through a cable connected to an electronic device (CU). As an example, the vehicle (1) may receive an image or an analysis result of the image acquired by the electronic device (CU) and perform a designated function according to the received result.

[0089] According to an embodiment, an electronic device (CU) is connected to a camera device (100) to perform image acquisition of a driver and, after performing analysis on the acquired image, can perform various set function processing (e.g., deceleration processing, hazard light turn-on or turn-off, horn device control, vehicle vibration control, window opening / closing control, etc.) according to the analysis result. In addition, various additional function processing may be implemented in addition to these function processing.

[0090] The driver, as a person capable of controlling the steering device while seated in the driver's seat, can be the subject of video recording by an electronic device (CU). In the present invention, the electronic device (CU) acquiring an image of the driver seated in the driver's seat is described as a representative example, but the present invention is not limited thereto. For example, the monitoring system can acquire images of not only the driver but also a passenger seated in the auxiliary seat or other seats. Accordingly, the monitoring system may be applied to control the method of acquiring images of various actions of the passenger. In this regard, at least one electronic device (CU) may be installed in the vehicle (1). For example, a camera device (100) and an electronic device (CU) may be installed to acquire an image of the driver seated in the driver's seat, which supports only driver monitoring.

[0091] Alternatively, if a monitoring function for the driver and passenger is supported, a plurality of electronic devices (CU) may be placed in the vehicle (1) to enable image acquisition of the driver's seat and passenger seats.

[0092] Referring further to FIG. 2, an electronic device (CU) can receive image information regarding the driver's face (A2) via a camera device (100). Accordingly, the electronic device (CU) can determine the driver's drowsiness in a predetermined manner and provide various feedback (e.g., alarms) corresponding thereto. For example, the electronic device (CU) can determine whether the driver is drowsy based on the user's eye track, iris size, or changes in size. Additionally, the electronic device (CU) can receive image information regarding the driver's hands (A1, A3) as well as the user's face (A2) from the camera device (100). Accordingly, the electronic device (CU) can easily determine the driver's hands-off state. In other words, a driver monitoring system having a hands-off monitoring function can be implemented. As a result, the driver's state of concentration or drowsiness can be easily determined based on various movements of the driver following the driver's hands-off.

[0093] The camera device (100) can be positioned in a location within the vehicle where the occupant can be easily photographed. For example, it can be positioned in various specific locations of the vehicle (1), such as the windshield (e.g., the location where the head-up display is placed), the bottom of the windshield, the dashboard, the instrument panel, etc., so as to acquire an image of a subject seated in the driver's seat. Furthermore, the camera device (100) may be positioned in a location that is difficult for the occupant to easily perceive.

[0094] Additionally, a camera device (100) connected to an electronic device (CU) is positioned at a predetermined location within the vehicle (1) to receive image information regarding passengers other than the driver of the vehicle (1). For example, there may be at least one camera device (100) and it may be positioned on a rearview mirror (or room mirror), etc., to detect all passengers other than the driver. Thus, the camera device (100) can generate an image of all passengers.

[0095] Thus, the camera device (100) can generate image information of other passengers (A5, A6, A7) other than the driver (A4) in the vehicle. And the electronic device (CU) can receive image information including passengers other than the driver. With this configuration, a monitoring system for not only the driver but also other passengers can be easily implemented.

[0096] Referring to FIG. 3, the monitoring method according to the embodiment may include the step of driving a camera device or module (S310), the step of receiving image information (S320), and the step of providing a preset function processing (e.g., alarm, emergency light turn on / off, horn, etc.) by analyzing the image information (S330).

[0097] First, the aforementioned processor, etc., can drive a camera device or module (S310). The camera device may operate in specific situations or at specific times. For example, the camera device may be driven when the vehicle is moving. When the vehicle is not moving, the camera device may or may not be driven. For example, the driving status of the vehicle may be determined based on whether it is moving or not through navigation, etc., and if the result of the determination is that it is moving, the driving status of the camera device may be determined (e.g., start camera driving when moving).

[0098] The camera device can generate an image of the driver or passenger by means of a control unit or a processor (S320). As described below, an image of an object or subject can be generated through a light source unit, a light guide device, a light receiving unit, etc.

[0099] Then, image information generated from the camera device can be analyzed by a control unit or a processor, and pre-set function processing can be performed through the analysis (S330). For example, the electronic device or the control unit can determine whether the driver is drowsy based on the position change or persistence of the change of feature points on the driver's face in the image information. For example, the reference position for the change in the position of the feature points can correspond to the average value of the position of the driver's eye feature points for a certain period of time after driving begins. In addition, since the monitoring method according to the embodiment can accurately calculate the position and position change of the eye feature points by applying depth information, the driver's drowsiness state can be accurately monitored, and thus the reliability of the product can be improved.

[0100] Each of the aforementioned steps can be implemented by a control unit, processor, etc., within an electronic device (CU) or camera device as described above.

[0101] FIG. 4 is a block diagram of a camera device according to an embodiment, FIG. 5 is a diagram showing the configuration of a camera device according to an embodiment, and FIG. 6 is a diagram explaining the operation of a camera device according to an embodiment.

[0102] Referring to FIG. 4, a camera device (100) according to an embodiment may include a light source unit (110), a light guide device (120), a light receiving unit (130), and a control unit (140).

[0103] First, the light source unit (110) can output light by means of a control signal. Finally, the light output from the light source unit (110) can be irradiated onto an object. The light irradiated onto the object can then be reflected and provided to the light receiving unit (130).

[0104] The light source unit (110) may include at least one light source. The at least one light source may emit light of a predetermined wavelength band or light having a predetermined center wavelength. Additionally, the light source of the light source unit (110) may emit light of a predetermined pattern according to a pre-designed algorithm. This light source unit (110) may output light under the control of the control unit (140).

[0105] In the following description, output light or incident light refers to light that is output from the light source unit (110) and provided to an object, and input light or reflected light may refer to light that is output from the light source unit (110), reaches the object, is reflected from the object, and is input to the light receiving unit (130). That is, from the perspective of the object, output light can be incident light, and input light can be reflected light.

[0106] At least one light source of the light source unit (110) can output light of a predetermined wavelength band. For example, the wavelength of the light output from the light source may be infrared light with a wavelength of 770 nm to 3000 nm. In addition, the wavelength of the light output from the light source may be visible light with a wavelength of 380 nm to 770 nm. Furthermore, the light source of the light source unit (110) may emit light other than the aforementioned wavelength range. In particular, as described above, the light source may irradiate light of a specific wavelength band so as not to be harmful to occupants such as the driver and passenger inside the vehicle, or irradiate light of a specific energy or lower so as not to be harmful.

[0107] The light source may include a light-emitting diode (LED), an organic light-emitting diode (OLED), a laser diode (LD), a vertical-cavity surface-emitting laser (VCSEL), a plasma lamp, a fluorescent lamp, a xenon lamp, a halogen lamp, a neon lamp, etc. It may output a wavelength of about 800 nm to 1000 nm, for example, about 850 nm or about 940 nm.

[0108] The light guide device (120) can be positioned adjacent to the light source unit (110) and the light receiving unit (130). The light guide device (120) can guide light irradiated from the light source unit (110) and deliver it to an object. The light guide device (120) can also guide light reflected from the object back to the light receiving unit (130). In this way, the light guide device (120) can be configured to control light and move it along a desired path. In other words, the light guide device (120) can perform both delivering light to an object (O) and receiving reflected light. Accordingly, the light guide device (120) can be configured to help light from the camera device (100) reach the sensor accurately or guide it along a specific path so that optical information is accurately delivered.

[0109] Such light guide devices (120) may be made of various materials capable of guiding light. For example, the light guide device (120) may be made of materials such as glass, polymer, or silicon. The light guide device (120) may include various other materials capable of guiding light.

[0110] And the light guide device (120) can transmit light in a desired direction using diffraction. Accordingly, the light guide device (120) may include an optical element for determining the path of light in a substrate that is a waveguide. The optical element may include various elements that operate based on diffraction.

[0111] In an example, the light guide device (120) may include a diffraction element which is a holographic optical element (HOE). The light guide device (120) may include an input diffraction element, an input / output diffraction element, and an output diffraction element as described below. For example, the input diffraction element, the input / output diffraction element, and the output diffraction element may be composed of holographic optical elements.

[0112] Furthermore, holographic optical elements diffract light using interference patterns generated through laser interference, thereby enabling the control of light of specific wavelengths or diffraction in desired directions. Bragg's Law applies during this diffraction process, and the diffraction angle can be determined by the wavelength of the light and the structure of the holographic optical element.

[0113] A holographic optical element can be composed of an interference pattern recorded on a transparent substrate. As previously mentioned, the transparent substrate can be a waveguide and can be made of various materials such as glass, plastic, or polymer. The interference pattern of the holographic optical element can be precisely designed inside or on the surface of the substrate to guide light in a specific direction. Furthermore, holographic optical elements can be classified into a transmissive type, in which light diffracts as it passes through, and a reflective type, in which light diffracts as it is reflected. Accordingly, the position of the holographic optical element can change on the substrate. By precisely controlling light through such a holographic optical element, high-resolution images can be provided. Additionally, the holographic optical element can support high-speed data transmission in optical communication through wavelength separation and coupling. Moreover, since the holographic optical element is lighter and thinner than conventional lenses or mirrors, it can provide a miniaturized camera device. A detailed description of the input diffraction element, input / output diffraction element, and output diffraction element, which are diffraction elements in the light guide device (120), will be provided later.

[0114] The light receiving unit (130) can receive light transmitted through the light guide device (120). The light receiving unit (130) may include an image sensor. The image sensor can receive light reflected from an object. Accordingly, the image sensor can detect light and convert it into an electrical signal. For example, the image sensor can generate a digital image by converting the electrical signal. The image sensor may include a Charge-Coupled Device (CCD), a Complementary Metal-Oxide-Semiconductor (CMOS), an InGaAs (Indium Gallium Arsenide) sensor, a Mercury Cadmium Telluride (HgCdTe) sensor, a microbolometer, etc. The light receiving unit (130) may also include an image sensor that receives light of various wavelength bands other than those described above or examples.

[0115] The light receiving unit (130) may also be located adjacent to the light guide device (120), just like the light source unit (110). Alternatively, an additional lens (not shown) may be placed between the light receiving unit (130) and the light guide device (120). This may also be applied equally between the light source unit (110) and the light guide device (120).

[0116] The control unit (140) can control the operation of the light source unit (110) and the light receiving unit (130). The control unit (140) can generate depth information based on an image generated by the light receiving unit (130) or transmit and receive image information with other electronic devices, such as a vehicle. This control unit (140) can control the operation within the camera device and can also communicate with a processor, etc., within an external electronic device, such as a vehicle.

[0117] The control unit (140) may include a processor, a microcontroller (MCU), a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), etc., and may also be implemented in the form of an Application Processor (AP) of various electronic devices.

[0118] Referring to FIGS. 5 and 6, the light guide device (120) may include a substrate (WG), an input diffraction element (121), an input / output diffraction element (122), and an output diffraction element (123).

[0119] The input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) may be placed on a substrate (WG) which is a waveguide. The input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) correspond to either a light-transmitting type or a reflective type, and may be located on either one side (e.g., the top surface) or the other side (e.g., the bottom surface) of the substrate (WG).

[0120] And the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) are diffraction elements as described above and can be spaced apart from each other.

[0121] The input diffraction element (121) can be configured such that the incident angle of the optical axis in the light irradiated from the light source (110) varies according to the wavelength based on the grating vector of the input diffraction element (121). A detailed explanation thereof will be provided later.

[0122] And the input diffraction element (121) may be composed of a plurality of diffraction elements or may include a plurality of regions. For example, the input diffraction element (121) may be composed of a single diffraction element. In an embodiment, when the input diffraction element (121) is composed of a plurality of sub-elements, the plurality of sub-elements may be spaced apart from each other or formed as a single unit.

[0123] In an example, light (L1) emitted from a light source unit (110) can be input to an input diffraction element (121). The input diffraction element (121) can diffract the light irradiated from the light source unit (110) and guide it into the substrate (WG) (L2). The input diffraction element (121) diffracts the light (L1) provided from the light source unit (110), and the diffracted light (L2) can move toward the input / output diffraction element (122) while undergoing total internal reflection within the substrate (WG). That is, the light (L2) guided into the substrate (WG) can be provided to the input / output diffraction element (122).

[0124] The input / output diffraction element (122) can diffract light (L2) guided from the input diffraction element (121) to the substrate (WG) toward the object (O) (L3), and diffract light (L4) reflected from the object (O). The light (L5) diffracted from the input / output diffraction element (122) can be guided by total internal reflection within the substrate (WG). That is, the input / output diffraction element (122) can diffract light toward the object (O) or diffract light reflected from the object (O) into the substrate (WG).

[0125] At this time, the object (O) may be various objects outside the camera device or the light guide device (120). That is, the object (O) is a various object that can be detected or recognized through the camera device, and may include people, cars, animals, buildings, etc. For example, a passenger inside a vehicle or a building or object outside the vehicle may correspond to the object.

[0126] And the light (L4) provided to the input / output diffraction element (122) can be diffracted at the input / output diffraction element (122) and the light path can be changed. Accordingly, the input / output diffraction element (122) diffracts the light (L4) reflected from the object (O) and guides it to the substrate (WG), and the light (L5) diffracted at the input / output diffraction element (122) and guided to the substrate (WG) can be guided to the output diffraction element (123).

[0127] And the output diffraction element (123) can diffract light (L5) that is reflected from the object (O) and guided to the substrate (WG) by the input / output diffraction element (122), and guide or provide it to the light receiving unit (130). At this time, the light (L6) that is diffracted from the output diffraction element (123) and guided to the light receiving unit (130) is incident on the light receiving unit (130) and can be converted into image information.

[0128] The camera device according to the present embodiment may consist of an illumination system and an imaging system. The illumination system can perform the role of illuminating a target with light in an optical system. This illumination system can help the target or subject to be seen clearly by uniformly dispersing or concentrating the light. The imaging system can perform the role of forming an image of the target in an optical system. This imaging system can collect light to focus it and form an image on an image sensor, film, or the eye. These illumination and imaging systems work together in an optical system to play an important role in forming an accurate and sharp image.

[0129] The illumination system may consist of components along a path through which light emitted from a light source unit (110) passes through an input diffraction element (121), a substrate (WG), and an input / output diffraction element (122) to be provided to an object (O). The imaging system may consist of components along a path through which light reflected from the object (O) passes through an input / output diffraction element (122), a substrate (WG), and an output diffraction element (123) to be provided to a light receiving unit (130). For example, the illumination system may include a light source unit, an input diffraction element (121), a substrate (WG), and an input / output diffraction element (122). The imaging system may include an input / output diffraction element (122), a substrate (WG), an output diffraction element (123), and a light receiving unit (130). The camera device may include components (e.g., a substrate, an input / output diffraction element) that belong to both the illumination system and the imaging system.

[0130] FIG. 8 is a cross-sectional view of a light guide device viewed by cutting along II' in FIG. 7, FIG. 9 is a partial enlarged view of FIG. 8, and FIG. 10 and FIG. 11 are drawings explaining the effect of the light guide device in a camera device according to an embodiment.

[0131] Referring to FIGS. 7 and 8, in the camera device (100) according to the embodiment, the light source unit (110) may include at least one light source. In the embodiment, the light source unit (110) may include a plurality of light sources corresponding to the input diffraction element.

[0132] And the input diffraction element (121) may be multiple, corresponding to the number of light sources. However, the following description is based on one input diffraction element (121).

[0133] In an example, the light source unit (110) can emit light of different wavelengths. Accordingly, diffraction can be performed at different angles for different wavelengths for the light irradiated from the light source unit (110) based on the grating vector of the input diffraction element (121).

[0134] For example, if the wavelength of light emitted from a light source decreases, the input diffraction element (121) may increase the diffraction angle (or diffraction angle) of the optical axis for the light irradiated from the light source (110) based on the grating vector of the input diffraction element (121). Conversely, if the wavelength of light emitted from a light source increases, the input diffraction element (121) may decrease the diffraction angle of the optical axis for the light based on the grating vector of the input diffraction element (121). The diffraction angle or diffraction angle may be the angle formed by the diffracted light with respect to the optical axis (NL) (or normal to the substrate, normal to the diffraction element, NL).

[0135] In this way, for light with a large wavelength, the angle of incidence of the optical axis can be reduced relative to the grating vector of the input diffraction element (121). Conversely, for light with a small wavelength, the angle of incidence of the optical axis can be increased relative to the grating vector of the input diffraction element (121). Additionally, for light with a large wavelength, the diffraction angle diffracted by the diffraction element can be small. And for light with a small wavelength, the diffraction angle diffracted by the diffraction element can be small. That is, for light incident on the diffraction element, the angle of incidence of the optical axis relative to the grating vector can change depending on the wavelength. Thus, even if the light emitted from the light source unit (110) consists of light of different wavelengths, it can be diffracted into the substrate (WG) with high efficiency by the diffraction element.

[0136] Furthermore, the light diffracted from the diffraction element may be guided to the substrate (WG) or provided to the outside. For example, some of the light incident on the input diffraction element (121) may be diffracted and totally reflected within the substrate (WG). Accordingly, some of the light incident on the input diffraction element (121) may not be totally reflected within the substrate (WG) after diffraction. Accordingly, the light provided to the object may be guided only within the substrate (WG) in a specific wavelength band corresponding to the wavelength, etc. That is, light of a specific wavelength may not be totally reflected within the substrate (WG). In addition, as described above, the diffraction angle of the light may change depending on the wavelength. Thus, the diffraction angle of the light diffracted from the input diffraction element (121) may differ depending on the wavelength.

[0137] In the light guide device according to the embodiment, the light diffracted from each diffraction element may differ depending on the wavelength. For example, the light diffracted from the input diffraction element (121) and guided within the substrate (WG) may have a wavelength greater than or equal to the first wavelength (λ1), which is the minimum wavelength. Additionally, the light diffracted from each input diffraction element (121) and guided within the substrate (WG) in the light guide device may have a wavelength less than or equal to the second wavelength (λ2), which is the maximum wavelength. In other words, the wavelength of the light diffracted from each input diffraction element (121) and guided within the substrate (WG) in the light guide device may have a range of the first wavelength (λ1) to the second wavelength (λ2).

[0138] In addition, in the embodiment, the angle of incidence of the light (LI1) of the first wavelength (λ1) and the angle of incidence of the light (LI2) of the second wavelength (λ2) may be angles formed in a clockwise (or counterclockwise) direction with respect to the optical axis (or normal, NL). In this case, the absolute values ​​of the angle of incidence of the light (LI1) of the first wavelength (λ1) and the angle of incidence of the light (LI2) of the second wavelength (λ2) may be the same. That is, the absolute value of the angle of incidence of the light (LI1) of the first wavelength (λ1) may be the same as the absolute value of the angle of incidence of the light (LI2) of the second wavelength (λ2). Furthermore, the light (LI1) of the first wavelength (λ1) and the light (LI2) of the second wavelength (λ2) may be formed symmetrically with respect to the optical axis or normal (NL). For example, furthermore, the range formed by the first angle of incidence and the second angle of incidence may be the field of view (fov) of the light guide device. For example, if the first angle of incidence is -10 degrees and the second angle of incidence is +10 degrees, the viewing angle may be 20 degrees. Furthermore, light of an intermediate wavelength between the first wavelength (λ1) and the second wavelength (λ2) may be incident parallel to the optical axis (or normal, NL). With this configuration, the fabrication and implementation of the light guide device may be easy. In addition, the wavelength-specific light described below may be guided on the substrate (WG) when conditions such as the grating equation of the diffraction element and the refractive index of the substrate (WG) for total reflection are met.

[0139] Furthermore, light incident on the input diffraction element (121) may have a diffraction angle ranging from a second diffraction angle (θ2) to a first diffraction angle (θ1). That is, light (LI1) of a first wavelength (λ1) may be diffracted at the input diffraction element (121) at a first diffraction angle (θ1). And light (LI2) of a second wavelength (λ2) may be diffracted at the input diffraction element (121) at a second diffraction angle (θ2). In other words, the first diffraction angle (θ1) is a diffraction angle corresponding to the first wavelength (λ1), and the second diffraction angle (θ2) is a diffraction angle corresponding to the second wavelength (λ2). And according to the embodiment, the first diffraction angle (θ1) may be larger than the second diffraction angle (θ2).

[0140] Additionally, in the camera device according to the embodiment, the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) may have the same diffraction vector. When a folding diffraction element that changes the light path within the substrate, etc., is not placed as an additional diffraction element, the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) may have the same grating vector. For example, the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) may be formed with the same period of 433 nm. Furthermore, depending on the position of the light incident from any one of the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) (the lower or upper surface of the diffraction element), the diffraction direction may be opposite (e.g., 180 degrees or ±).

[0141] At this time, the light guide device (120) may include a blocking member disposed in at least a portion of the substrate (WG) other than the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123).

[0142] The blocking member may include a black coating, etc. The blocking member can reduce light reflection or interference and prevent unwanted optical signals. Such a blocking member can be applied to the inside or outside of the substrate (WG). For example, the blocking member may be located on the outer surface of the substrate, excluding the top and bottom surfaces. The blocking member can remove stray light, such as by absorbing light, and suppress internal reflection of light. For example, the blocking member may be made of various light-absorbing materials. For example, the blocking member may include carbon black, matte black paint, velvet coating, nano coating, ceramic black, etc.

[0143] Additionally, in the camera device according to the embodiment, the input diffraction element (121) and the output diffraction element (123) of the light guide device (120) may be spaced apart along a third direction (Z-axis direction). The input diffraction element (121) and the output diffraction element (123) may overlap at least partially in the third direction (Z-axis direction). With this configuration, the arrangement of the input diffraction element and the output diffraction element in the light guide device is easy, and the miniaturization of the light guide device can be easily realized.

[0144] In addition, the input diffraction element (121) and the output diffraction element (123) may be spaced apart from the input / output diffraction element (122) in a first direction (X-axis direction). A groove or a blocking part (GR) may exist in the region between the input diffraction element (121) and the output diffraction element (123). The groove or blocking part (GR) may be made of a material with a refractive index different from that of the substrate (WG), such as air. As described above, light guided from the input diffraction element (121) is guided toward the input / output diffraction element (122), and this guiding direction may be parallel to the first direction. Then, light incident on the input / output diffraction element (122) (light reflected from an object) may diffract and be guided from the substrate (WG) along the opposite direction of the first direction and provided to the output diffraction element (123). In this way, the input diffraction element (121) and the output diffraction element (123) are located on the same side from the input / output diffraction element (122), and the guiding area of ​​the diffracted light can be shared with each other. Accordingly, the groove or prevention part (GR) can minimize light interference or reflection between the input diffraction element (121) and the output diffraction element (123), which are located on the same side from the input / output diffraction element (122). In other words, optical interference is reduced, and the quality of the image information generated in the image sensor can be improved.

[0145] Additionally, the grating vectors of the input diffraction element (121), input / output diffraction element (122), and output diffraction element (123) may all be the same when no additional diffraction element controlling an additional optical path is placed on the substrate (WG). As described later, when additional diffraction elements, such as a folding diffraction element, are placed on the substrate (WG), the grating vectors for the diffraction elements may be different from each other.

[0146] And the substrate (WG) may include a first surface (e.g., an upper surface (US)) and a second surface (e.g., a lower surface (BS)). The first surface (US) and the second surface (BS) may be surfaces facing each other within the substrate (WG).

[0147] Each of the input diffraction element (121), input / output diffraction element (122), and output diffraction element (123) may be placed on either the first surface (US) or the second surface (BS) of the substrate (WG). For example, at least two of the input diffraction element (121), input / output diffraction element (122), and output diffraction element (123) may be placed on the same surface of the substrate (WG).

[0148] For example, the input diffraction element (121) and the output diffraction element (123) may be placed on the lower surface (BS) of the substrate (WG). The input diffraction element (121) may also be placed on the upper surface (US) of the substrate (WG). Furthermore, the input diffraction element (121) and the input / output diffraction element (122) may also be spaced apart from each other in a first direction.

[0149] In addition, in the light guide device (120) according to the embodiment, the length (L1) in the first direction (X-axis direction) of the input diffraction element (121) may be smaller than the horizontal distance traveled by the light of the first wavelength (LI1), which is the minimum wavelength, or the light of the second wavelength (LI2), which is the maximum wavelength, being reflected twice. For example, in the light guide device (120), the length (L1) in the first direction (X-axis direction) of the input diffraction element (121) may be smaller than the horizontal distance traveled by the light of the first wavelength (LI1), which is reflected twice, within the substrate (WG). Furthermore, the length (L1) in the first direction (X-axis direction) of the input diffraction element (121) may be smaller than the horizontal distance traveled by the light of the second wavelength, which is reflected twice, within the substrate (WG). Moreover, the length (L1) in the first direction (X-axis direction) of the input diffraction element (121) may satisfy Equations 1 and 2.

[0150] [Equation 1]

[0151]

[0152] [Equation 2]

[0153]

[0154] Here, a is the length in the first direction of the input diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle.

[0155] With this configuration, the amount of light diffracted by the input / output diffraction element (122) and provided to the object can be maximized. Furthermore, light of the most uniform amount for each wavelength can be provided to and received by the object. As a result, an improved image can be provided regardless of distance, and improved image quality can be secured.

[0156] Additionally, the light (L3a, L3b, L3c) diffracted by the input / output diffraction element (122) may be totally reflected n times with respect to the input diffraction element (121). That is, the light diffracted by the input / output diffraction element (122) may be diffracted from the input diffraction element (121) and totally reflected n times. Furthermore, a portion of the light that has been totally reflected from the input diffraction element (121) n times may be diffracted by the input / output diffraction element (122) as described above and provided as an object. Additionally, at least a portion of the light that has been totally reflected from the input diffraction element (121) n times may not be diffracted by the input / output diffraction element (122). That is, all light diffracted by the input / output diffraction element (122) has the same total reflection count of n (n is 0 or greater), but not all light with a total reflection count of n may be diffracted by the input / output diffraction element (122).

[0157] In addition, the light diffracted from the input / output diffraction element (122) in the light guide device (120) according to the embodiment may have the same number of total reflections from the input diffraction element (121). That is, when light having different wavelengths or the same wavelength is diffracted from the input / output diffraction element (122) and emitted to an object, the light diffracted from the input / output diffraction element (122) may have the same number of total reflections from the substrate (WG) after being diffracted from the input diffraction element (121). By this configuration, double images of the light output to the object can be suppressed. Thus, the occurrence of double images of the object in the aforementioned image can be prevented. Accordingly, the camera device according to the embodiment can provide improved image quality.

[0158] Referring further to FIGS. 10 and FIGS. 11, FIG. 10(a) shows an image of a normal object (FG) without a double image phenomenon, while FIG. 10(b) shows that both the object (FG) and a double image of the object (FG') are present in the image due to the double image phenomenon. Similarly, FIG. 11 shows that a double image (PI) may occur in some fields. A field may refer to light with the same diffraction angle. As illustrated, it can be seen that when light with different total reflection counts is provided to the input / output device, a somewhat blurry image may occur due to diffraction at the input / output diffraction element.

[0159] Furthermore, the light diffracted by the input / output diffraction element (122) can satisfy the following Equation 3.

[0160] [Equation 3]

[0161] , n is an integer greater than 0

[0162] Likewise, in Equation 3, a is the length in the first direction of the input diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle. Thus, the aforementioned double image generation can be suppressed.

[0163] Furthermore, the length (L2) in the first direction (X-axis direction) of the input / output diffraction element (122) may be greater than the thickness (t) of the substrate (WG) and smaller than the length (L1) in the first direction (X-axis direction) of the input diffraction element (121). With this configuration, the input / output diffraction element (122) has a length in the appropriate first direction (X-axis direction), thereby eliminating double images and improving image quality.

[0164] In particular, the gap in the first direction (X-axis direction) between one end of the input / output diffraction element (122) and one end of the input diffraction element (121) may be greater than the possible horizontal distance that light travels by reflecting once within the substrate (WG). Specifically, the gap in the first direction (X-axis direction) between one end of the input / output diffraction element (122) and one end of the input diffraction element (121) may be greater than the horizontal distance that light of the first wavelength (LI1) travels by reflecting once within the substrate (WG). Additionally, the gap in the first direction (X-axis direction) between one end of the input / output diffraction element (122) and one end of the input diffraction element (121) may be smaller than the sum of the distance that light of the second wavelength (LI2) travels by reflecting once within the substrate (WG) and the length (L1) in the first direction of the input diffraction element (121).

[0165] That is, the gap in the first direction (X-axis direction) between one end of the input / output diffraction element (122) and one end of the input diffraction element (121) can satisfy Equation 4.

[0166] [Equation 4]

[0167]

[0168] Likewise, gap is the distance between one end of the input / output diffraction element and one end of the input diffraction element, a is the length in the first direction of the input diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle.

[0169] With this configuration, the viewing angle of the light diffracted by the input / output diffraction element (122) is secured, and the amount of light provided to the object is increased and a uniform amount of light can also be provided to the object.

[0170] Furthermore, if the length (L1) in the first direction (X-axis direction) of the input diffraction element (121) is smaller than the thickness (t) of the substrate (WG), the following Equation 5 can be satisfied.

[0171] [Equation 5]

[0172]

[0173] In Equation 5, b is the length in the first direction of the input / output diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle.

[0174] With this configuration, double-phase generation suppression can be effectively implemented.

[0175] Likewise, if the length in the first direction of the input diffraction element is greater than the thickness of the substrate, the following Equation 6 can be satisfied.

[0176] [Equation 6]

[0177]

[0178] In Equation 6, b is the length in the first direction of the input / output diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle.

[0179] Thus, even if the length (L2) in the first direction (X-axis direction) of the input / output diffraction element (122) is fixed or changed, the length (L1) in the first direction (X-axis direction) of the input diffraction element (121) is designed to conform to Equations 5 and 6, thereby easily implementing image quality improvement due to double image removal.

[0180] Furthermore, according to the embodiment, the input / output diffraction element (122) may be spaced apart from the input diffraction element (121) in a first direction (X-axis direction). As illustrated, the input / output diffraction element (122) may not overlap with the input diffraction element (121) in a second direction (Y-axis direction). This improves the field of view of the camera device. In this specification, the second direction (Y-axis direction) may correspond to the thickness direction of the substrate (WG). Furthermore, the third direction (Z-axis direction) is a direction perpendicular to the first direction (X-axis direction) and the second direction (Y-axis direction).

[0181] FIG. 12 is a cross-sectional view of another example of a light guide device in a camera device according to an embodiment, and FIG. 13 is a cross-sectional view of yet another example of a light guide device in a camera device according to an embodiment.

[0182] Referring to FIG. 12, another example of an optical guide device (120) may include a substrate (WG), an input diffraction element (121), an input / output diffraction element (122), and an output diffraction element (123). Additionally, in the optical guide device (120), the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) may be placed on the substrate (WG), which is a waveguide. Furthermore, the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) correspond to either a light-transmitting type or a reflective type, and may be located on either one side (e.g., the top side) or the other side (e.g., the bottom side) of the substrate (WG). Also, the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) are diffraction elements as described above and may be spaced apart from each other. And, excluding the details explained below, the above-described content may apply in the same way.

[0183] The input diffraction element (121) and the input / output diffraction element (122) may be placed on different sides of the substrate (WG). The input diffraction element (121) may be placed offset from the input / output diffraction element (122) in a second direction (Y-axis direction). For example, the input diffraction element (121) may not overlap with the input / output diffraction element (122) in the second direction (Y-axis direction).

[0184] Furthermore, the distance in the first direction (X-axis direction) between one end of the input / output diffraction element (122) and one end of the input diffraction element (121) can correspond to the length in the first direction (X-axis direction) of the input diffraction element (121).

[0185] Furthermore, an input / output diffraction element (122) may be positioned in an overlapping area where the horizontal distance traveled by the second wavelength light (LI2), which is the maximum wavelength, being diffracted by the input diffraction element (121) and totally reflected n times inside the substrate (WG), and the horizontal distance traveled by the first wavelength light (LI1), which is the minimum wavelength, being diffracted by the input diffraction element (121) and totally reflected n times inside the substrate (WG) overlap. Furthermore, the input / output diffraction element (122) may have a length corresponding to the length of the overlapping area based on the horizontal distance traveled by the first wavelength light and the second wavelength light having the same number of total reflections being totally reflected once.

[0186] For example, as illustrated, when the total reflection count is 1, a first region (CA1) corresponding to the horizontal distance traveled by light of the second wavelength being diffracted by the input diffraction element (121) and totally reflected once inside the substrate (WG), and a second region (CA2) corresponding to the horizontal distance traveled by light of the first wavelength being diffracted by the input diffraction element (121) and totally reflected once inside the substrate (WG) may have an overlapping region (OV). At this time, the input / output diffraction element (122) may be located in the overlapping region (OV). Furthermore, the maximum length (L2) in the first direction (X-axis direction) of the input / output diffraction element (122) may correspond to the length in the first direction (x-axis direction) of the overlapping region (OV).

[0187] Referring to FIG. 13, another example of an optical guide device (120) may include a substrate (WG), an input diffraction element (121), an input / output diffraction element (122), and an output diffraction element (123). Additionally, in the optical guide device (120), the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) may be placed on the substrate (WG), which is a waveguide. Furthermore, the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) correspond to either a light-transmitting type or a reflective type, and may be located on either one side (e.g., the top surface) or the other side (e.g., the bottom surface) of the substrate (WG). Also, the input diffraction element (121), the input / output diffraction element (122), and the output diffraction element (123) are diffraction elements as described above and may be spaced apart from each other. And, excluding the details explained below, the above-described content may apply in the same way.

[0188] The input diffraction element (121) and the input / output diffraction element (122) may be placed on different sides of the substrate (WG). The input / output diffraction element (122) may be located in the region between one end and the other end of the input diffraction element (121). For example, the input diffraction element (121) may overlap with the input / output diffraction element (122) in a second direction (Y-axis direction). With this configuration, the length in the first direction of the substrate (WG) is reduced, making it easy to miniaturize the light guide device.

[0189] Furthermore, an input / output diffraction element (122) may be positioned in an overlapping area where the horizontal distance traveled by the second wavelength light (LI2), which is the maximum wavelength, being diffracted by the input diffraction element (121) and totally reflected n times inside the substrate (WG), and the horizontal distance traveled by the first wavelength light (LI1), which is the minimum wavelength, being diffracted by the input diffraction element (121) and totally reflected n times inside the substrate (WG) overlap. Furthermore, the input / output diffraction element (122) may have a length corresponding to the length of the overlapping area where the first wavelength light (LI1) and the second wavelength light (LI2), which have the same number of total reflections, are totally reflected once and travel.

[0190] For example, as illustrated, when the total reflection count is 1, a first region (CA1) corresponding to the horizontal distance traveled by the second wavelength light (LI2) being diffracted by the input diffraction element (121) and totally reflected n times within the substrate (WG), and a second region (CA2') corresponding to the horizontal distance traveled by the first wavelength light (LI1) being diffracted by the input diffraction element (121) and totally reflected n times within the substrate (WG) may have an overlapping region (OV). At this time, the input / output diffraction element (122) may be located in the overlapping region (OV). Furthermore, at least a portion (OV1) of the overlapping region (OV) may face the input diffraction element (121). That is, the overlapping region (OV) may overlap with the input diffraction element (121) in a vertical direction. Additionally, the input diffraction element (121) and the input / output diffraction element (122) may have an overlapping region (OV1) in a vertical direction. Furthermore, the maximum length (L2) in the first direction (X-axis direction) of the input / output diffraction element (122) can correspond to the length in the first direction (x-axis direction) of the overlap region (OV).

[0191] The features, structures, effects, etc. described in the embodiments above are included in at least one embodiment and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified and implemented in other embodiments by a person skilled in the art to which the embodiments belong. Therefore, details regarding such combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0192] Although the above description has focused on the embodiments, this is merely an example and is not intended to limit the embodiments. A person skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For instance, each component specifically shown in the embodiments may be modified and implemented. Furthermore, differences related to such modifications and applications should be interpreted as being included within the scope of the embodiments set forth in the appended claims.

Claims

1. A light source unit that emits light; A light guide device that guides light from the light source unit to irradiate an object and guides light reflected from the object; and A light receiving unit that receives light reflected and guided from the above object; The above light guide device is, Substrate; An input diffraction element disposed on the above substrate; Input / output diffraction element disposed on the above substrate and It includes an output diffraction element disposed on the above substrate, and A camera device in which the light diffracted by the input / output diffraction element is totally reflected from the input diffraction element the same number of times.

2. In Paragraph 1, A camera device in which light diffracted by the input diffraction element and guided within the substrate has a wavelength ranging from a minimum wavelength, which is a first wavelength, to a maximum wavelength, which is a second wavelength.

3. In Paragraph 2, A camera device in which the length in the first direction of the input diffraction element is smaller than the horizontal distance traveled by light of the first wavelength being reflected twice within the substrate.

4. In Paragraph 2, A camera device in which the length in the first direction of the input diffraction element is smaller than the horizontal distance traveled by the light of the second wavelength being reflected twice.

5. In Paragraph 2, The light of the first wavelength is incident on the input diffraction element at a first diffraction angle, and The light of the second wavelength is incident on the input diffraction element at a second diffraction angle, and A camera device in which the first diffraction angle is larger than the second diffraction angle.

6. In Paragraph 5, A camera device in which the length in the first direction of the input diffraction element satisfies the following Equations 1 and 2. [Equation 1] [Equation 2] (Here, a is the length in the first direction of the input diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle) 7. In Paragraph 2, A camera device in which light diffracted by the above input diffraction element has a different diffraction angle corresponding to the wavelength.

8. In Paragraph 1, The light diffracted by the input / output diffraction element has been totally reflected from the input diffraction element n times, and A camera device in which at least a portion of light that has been totally reflected from the input diffraction element n times is not diffracted by the input / output diffraction element.

9. In Paragraph 1, A camera device in which light diffracted by the above input / output diffraction element satisfies the following Equation 3. [Equation 3] , n is an integer greater than 0 (Here, a is the length in the first direction of the input diffraction element, t is the thickness of the substrate, θ1 is the first diffraction angle, and θ2 is the second diffraction angle) 10. In Paragraph 1, A camera device in which the length in the first direction of the input / output diffraction element is greater than the thickness of the substrate and smaller than the length in the first direction of the input diffraction element.

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