Projection device and electronic device including the same

Abstract

In one embodiment, a projection apparatus is disclosed, including: a light source unit; a light modulator for modulating light emitted from the light source unit; a prism disposed between the light modulator and the light source unit; a reflection unit disposed between the light modulator and the prism; a first lens disposed between the prism and the light source unit; and a second lens disposed between the first lens and the prism, in which an interval between the first lens and the second lens is 0.8 to 1.2 times a thickness of at least one of the first lens and the second lens.

Description

Technical Field

[0001] The embodiments relate to a projection device and an electronic device including the projection device. Background Technology

[0002] Virtual reality (VR) refers to a specific environment, situation, or technology itself generated using artificial technologies such as computers, which is similar to reality but is not real.

[0003] Augmented reality (AR) is a technology that combines virtual objects or information with the real environment to make the result look like objects that exist in the original environment.

[0004] Mixed reality (MR), or hybrid reality, refers to the creation of new environments or information by combining the virtual and real worlds. Specifically, it is called mixed reality when it refers to the ability for real-time interaction between things that exist in the real world and things that exist in the virtual world.

[0005] In this context, the generated virtual environments and situations stimulate the user's five senses and allow them to move freely between reality and imagination by providing a similar spatial and temporal experience. Furthermore, users can not only simply immerse themselves in these environments but also interact with things realized within them, such as manipulating them or issuing commands using real devices.

[0006] Recently, research has been actively conducted on devices (gears, mechanisms) used in these technological fields. However, the demand for miniaturization and improved optical performance of these devices is growing. Summary of the Invention Technical issues

[0007] The embodiments provide a projection device and an electronic device that are miniaturized and compacted by means of a lens at the rear end of the light source unit, for use as a projection device for augmented reality (AR) and the like, and an electronic device including the projection device.

[0008] Furthermore, projection devices and electronic devices with reduced size can be provided by controlling the shape of at least one surface of the lens.

[0009] The problems to be solved by the embodiments are not limited to those described herein, but also include objectives or effects that can be achieved from the solutions to the problems or embodiments described below. Technical solution

[0010] The projection device according to an embodiment includes: a light source unit; an optical modulator configured to modulate light emitted from the light source unit; a prism disposed between the optical modulator and the light source unit; a reflector disposed between the optical modulator and the prism; a first lens disposed between the prism and the light source unit; and a second lens disposed between the first lens and the prism, wherein the distance between the first lens and the second lens is 0.8 to 1.2 times the thickness of at least one of the first lens and the second lens.

[0011] The ratio of the size of the optical modulator to the total volume of the light source unit, the first lens, and the second lens can be in the range of 1:5 to 1:25 (inches:cc).

[0012] At least one of the first and second lenses can be a Fresnel lens.

[0013] The first lens and the second lens may be Fresnel lenses, each of which may include multiple lens regions, and the width of each of the multiple lens regions may decrease in a direction away from the center of each of the first lens and the second lens.

[0014] Each lens region may include multiple sub-regions, and the width of each sub-region may decrease in a direction away from the center of each of the first and second lenses.

[0015] Multiple sub-regions can correspond to each other on each of the light source unit side surface and the reflector side surface of the first lens.

[0016] The thickness of the first lens and the second lens can be the same.

[0017] The distance between the first lens and the second lens can be the same as the thickness of the first lens or the second lens.

[0018] In the first lens and the second lens, the light source unit side surface of the first lens can have the maximum radius of curvature.

[0019] In the second lens, the radius of curvature of the light source unit side surface and the radius of curvature of the reflector side surface can have different signs.

[0020] The projection device may include a projection lens unit located at the rear end of the optical modulator.

[0021] Light emitted from the light source unit can be transmitted through the prism, and light emitted from the optical modulator can be reflected by the prism.

[0022] The projection device according to an embodiment includes: a light source unit; an optical modulator configured to modulate light emitted from the light source unit; a prism disposed between the optical modulator and the light source unit; a reflector disposed between the optical modulator and the prism; a first lens disposed between the prism and the light source unit; and a second lens disposed between the first lens and the prism, wherein at least one of the first lens and the second lens has a first metasurface.

[0023] The first metasurface may be located on at least one of the light source unit side surface and the reflector side surface of the first lens and the second lens.

[0024] The first metasurface can be arranged to form a shape distribution that alters the phase of the incident light according to a predetermined rule depending on the location.

[0025] The first metasurface may include multiple patterned structures having a width or thickness smaller than the wavelength of the incident light.

[0026] Multiple structures can have cylindrical, polygonal, or strip shapes.

[0027] The projection device may include a front prism disposed between the reflector and the light source unit.

[0028] The front prism may include: an incident surface facing the light source unit; and an exit surface through which light incident through the incident surface is emitted.

[0029] The front prism may include a second metasurface located on the incident surface.

[0030] The ratio of the size of the optical modulator to the total volume of the light source unit, the first lens, and the second lens can be in the range of 1:5 to 1:25 (inches:cc).

[0031] The projection device may include a projection lens unit located at the rear end of the optical modulator.

[0032] In this system, light emitted from the light source unit can be transmitted through the prism, and light emitted from the optical modulator can be reflected by the prism. Beneficial effects

[0033] The embodiments implement a projection device and an electronic device that are miniaturized and compacted by means of a lens at the rear end of the light source unit, for use as a projection device for augmented reality (AR) and an electronic device including the projection device.

[0034] Furthermore, projection devices and electronic devices with reduced volume can be achieved by controlling the shape of at least one surface of the lens.

[0035] The various useful advantages and effects of the present invention are not limited to those described above, and can be more easily understood in the process of describing specific embodiments of the invention. Attached Figure Description

[0036] Figure 1 This is a block diagram illustrating the configuration of an extended reality electronic device according to an embodiment of the present invention.

[0037] Figure 2 This is a perspective view of an augmented reality electronic device according to an embodiment of the present invention.

[0038] Figure 3 This is a perspective view of the projection device according to an embodiment.

[0039] Figure 4 This is another perspective view of the projection device according to an embodiment.

[0040] Figure 5 This is an exploded perspective view of the projection device according to an embodiment.

[0041] Figure 6 It is along Figure 3 A sectional view of line A-A' in the middle.

[0042] Figure 7 and Figure 8 This is a view of the projection device according to an embodiment, wherein the housing has been removed.

[0043] Figure 9 This is a cross-sectional view of the light source unit, first lens, second lens, first reflector, second reflector, and third lens in the projection device according to an embodiment.

[0044] Figure 10 This is a cross-sectional view of the light source unit, first lens, second lens, first reflector, second reflector, and third lens in the projection device of the comparative example.

[0045] Figure 11 This is a perspective view of the first lens or the second lens in the projection device according to an embodiment.

[0046] Figure 12 This is a cross-sectional view of the first lens or the second lens in the projection device according to an embodiment.

[0047] Figure 13 This is another perspective view of the first lens or the second lens in the projection device according to an embodiment.

[0048] Figure 14 and Figure 15 This is a view illustrating the optical performance of the projection device according to the comparative example and embodiment.

[0049] Figure 16This is a configuration diagram of the light source unit side in the projection apparatus according to various examples, based on an embodiment.

[0050] Figure 17 This is a cross-sectional view of the light source unit, first lens, second lens, first reflector, second reflector, and third lens in a projection device according to another embodiment.

[0051] Figure 18 This is a schematic diagram of a metasurface applied to the rear end of a light source unit according to an embodiment.

[0052] Figure 19 This is a schematic perspective view of a metasurface according to another embodiment.

[0053] Figure 20 This is a schematic perspective view of a metasurface according to yet another embodiment.

[0054] Figure 21 This is a schematic perspective view of a metasurface according to yet another embodiment.

[0055] Figure 22 This is a schematic diagram of a metasurface according to yet another embodiment.

[0056] Figure 23 This is a schematic diagram of a metasurface according to yet another embodiment.

[0057] Figure 24 This is a schematic diagram of a metasurface according to yet another embodiment.

[0058] Figure 25 This is a cross-sectional view of the light source unit, first lens, second lens, first reflector, second reflector, and third lens in a projection device according to yet another embodiment.

[0059] Figure 26 This is an exploded perspective view showing a first reflector, a second reflector, and a metasurface in a projection device according to yet another embodiment. Detailed Implementation

[0060] In the following, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0061] However, the technical concept of the present invention is not limited to the embodiments to be described, but can be implemented in various different forms, and one or more components in the embodiments can be selectively combined or replaced and used within the scope of the technical concept of the present invention.

[0062] Furthermore, unless explicitly and specifically defined and described, the terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that is generally understood by one of ordinary skill in the art to which the present invention pertains, and commonly used terms (such as terms defined in dictionaries) may be interpreted in light of the contextual meaning of the relevant art.

[0063] Furthermore, the terminology used in the embodiments of the present invention is for the purpose of describing the embodiments and not for limiting the invention.

[0064] In this specification, unless otherwise specified in the phrase, the singular may also include the plural, and when it is 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.

[0065] Furthermore, when describing the components of embodiments of the present invention, terms such as first, second, A, B, (a), (b) may be used.

[0066] These terms are intended only to distinguish one component from another, and the nature, order, sequence, etc., of the components are not limited by these terms.

[0067] Furthermore, when a component is described as being “connected,” “coupled,” or “joined” to another component, it can include not only cases where the component is directly connected, coupled, or joined to another component, but also cases where the component is “connected,” “coupled,” or “joined” to other components between the component and the other component.

[0068] Furthermore, when a component is described as being formed or positioned "above (upper) or below (lower)" of another component, "above (upper)" or "below (lower)" includes not only the case where the two components are in direct contact with each other, but also the case where one or more other components are formed or positioned between the two components. Additionally, when expressed as "above (upper) or below (lower)", it can include meanings based on a component's orientation not only upwards but also downwards.

[0069] Figure 1 This is a block diagram illustrating the configuration of an extended reality electronic device according to an embodiment of the present invention.

[0070] refer to Figure 1 The extended reality electronic device 20 may include a wireless communication unit 21, an input unit 22, a sensing unit 23, an output unit 24, an interface unit 25, a memory 26, a control unit 27, a power supply unit 28, etc. Figure 1 The components shown are not necessary for implementing electronic device 20, therefore electronic device 20 described in this specification may have more or fewer components than those listed above.

[0071] More specifically, in the above-described components, the wireless communication unit 21 may include one or more modules for enabling wireless communication between the electronic device 20 and a wireless communication system, between the electronic device 20 and another electronic device, or between the electronic device 20 and an external server. Furthermore, the wireless communication unit 21 may include one or more modules for connecting the electronic device 20 to one or more networks.

[0072] The wireless communication unit 21 may include at least one of a broadcast receiving module, a mobile communication module, a wireless Internet module, a short-range communication module, and a location information module.

[0073] Input unit 22 may include a camera or video input unit for video signal input, a microphone or audio input unit for audio signal input, and a user input unit (e.g., touch keys, buttons (mechanical keys), etc.) for receiving information from the user. Voice or image data collected from input unit 22 can be analyzed and processed using user control commands.

[0074] The sensing unit 23 may include one or more sensors for detecting at least one of information in the electronic device 20, information about the surrounding environment around the electronic device 20, and user information.

[0075] For example, the sensing unit 23 may include at least one of a proximity sensor, an illuminance sensor, a touch sensor, an accelerometer, a magnetic sensor, a G-sensor, a gyroscope, a motion sensor, an RGB sensor, an infrared sensor (IR sensor), a finger scanning sensor, an ultrasonic sensor, an optical sensor (e.g., an imaging device), a microphone, a battery gauge, an environmental sensor (e.g., a barometer, a hygrometer, a thermometer, a radiation detection sensor, a thermal detection sensor, a gas detection sensor, etc.), and a chemical sensor (e.g., an electronic nose, a healthcare sensor, a biometric sensor, etc.). Furthermore, the electronic device 20 disclosed in this specification can utilize information detected by at least two of these sensors in combination.

[0076] The output unit 24 can be used to generate outputs related to vision, hearing, touch, etc., and may include at least one of a display unit, an audio output unit, a haptic module, and an optical output unit. The display unit can be implemented as a touch screen by forming an interlayer structure with the touch sensor or by integrating it with the touch sensor. The touch screen can be used as a user input device that provides an input interface between the augmented reality electronic device 20 and the user, and can also provide an output interface between the augmented reality electronic device 20 and the user.

[0077] The interface unit 25 serves as a channel for connecting to various types of external devices of the electronic device 20. Through the interface unit 25, the electronic device 20 can receive virtual reality or augmented reality content provided from external devices and perform mutual interaction by sending and receiving various input signals, detection signals, and data.

[0078] For example, interface unit 25 may include at least one of a wired / wireless headphone port, an external charger port, a wired / wireless data port, a memory card port, a port for connecting a device equipped with an identification module, an audio input / output (I / O) port, a video input / output (I / O) port, and a headphone port.

[0079] Furthermore, memory 26 can store data supporting various functions of electronic device 20. Memory 26 can store multiple applications (or applications) driven by electronic device 20, data for the operation of electronic device 20, and commands. At least some of these applications can be downloaded from an external server via wireless communication. Additionally, at least some of these applications may be present on electronic device 20 at the time of manufacture for basic functions of electronic device 20 (e.g., incoming and outgoing call functions, message receiving and sending functions).

[0080] In addition to operations related to the application, the control unit 27 typically controls the overall operation of the electronic device 20. The control unit 27 can process signals, data, information, etc., input or output through the aforementioned components.

[0081] Furthermore, the control unit 27 can control at least some components by driving the application stored in the memory 26 to provide the user with appropriate information or processing functions. Additionally, the control unit 27 can coordinately operate at least two or more of the components included in the electronic device 20 to drive the application.

[0082] Furthermore, the control unit 27 can detect the movement of the electronic device 20 or the user by using a gyroscope sensor, gravity sensor, motion sensor, etc., included in the sensing unit 23. Alternatively, the control unit 27 can detect objects approaching the electronic device 20 or the user by using a proximity sensor, illuminance sensor, magnetic sensor, infrared sensor, ultrasonic sensor, light sensor, etc., included in the sensing unit 23. Additionally, the control unit 27 can also detect the user's movement by using sensors provided in a controller that operates in conjunction with the electronic device 20.

[0083] In addition, the control unit 27 can use the application stored in the memory 26 to perform the operation (or function) of the electronic device 20.

[0084] The power supply unit 28 can receive external or internal power under the control of the control unit 27 and supply power to each component included in the electronic device 20. The power supply unit 28 may include a battery, which may be provided in a built-in or replaceable form.

[0085] At least some of the above-described components can cooperate with each other to implement the operation, control, or control method of the electronic device according to the various embodiments described below. Furthermore, the operation, control, or control method of the electronic device can be implemented on the electronic device by driving at least one application program stored in memory 26.

[0086] In the following description, an electronic device described as an example of the present invention will be based on an embodiment applied to a head-mounted display (HMD). However, embodiments of the electronic device according to the present invention may include mobile phones, smartphones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation devices, tablet PCs, portable PCs, ultrabooks, wearable devices, etc. Besides HMDs, wearable devices may also include watch-type terminals (smartwatches), contact lenses, VR / AR / MR glasses, etc.

[0087] Figure 2 This is a perspective view of an augmented reality electronic device according to an embodiment of the present invention.

[0088] like Figure 2 As shown, an electronic device according to an embodiment of the present invention may include a frame 100, a projection device 200, and a display unit 300.

[0089] The electronic device can be provided in the form of eyeglasses (smart glasses). The eyeglass-type electronic device is configured to be worn on the head and may include a frame 100 (shell, housing, etc.) for this purpose. The frame 100 may be formed of a flexible material for ease of wear.

[0090] The frame 100 can be supported on the head and provides space for mounting various components. As illustrated in the accompanying drawings, electronic components such as a projection device 200, a user input unit 130, or an audio output unit 140 can be mounted on the frame 100. Furthermore, lenses covering at least one of the left and right eyes can be detachably mounted on the frame 100.

[0091] The frame 100 may take the form of glasses worn on the user's face as shown in the attached figure, but is not limited to this, and may also take the form of goggles worn in close contact with the user's face.

[0092] Frame 100 may include a front frame 110 having at least one opening and a y-direction intersecting the front frame 110 (see [link]). Figure 2 A pair of side frames 120 that extend and are parallel to each other.

[0093] The frame 100 may have a length DI along the x-direction and a length LI along the y-direction, which may be the same or different.

[0094] The projection device 200 can be configured to control various electronic components located in the electronic device. The projection device 200 can be used interchangeably with "optical output device", "optical projection device", "light illumination device", "optical device", etc.

[0095] The projection device 200 can generate images or videos that include a series of images to be displayed to a user. The projection device 200 may include an image source panel for generating images, multiple lenses for diffusing and converging the light generated from the image source panel, etc.

[0096] The projection device 200 can be fixed to either of the two side frames 120. For example, the projection device 200 can be fixed to the inside or outside of either side frame 120, or it can be integrally formed by being built into either side frame 120. Alternatively, the projection device 200 can be fixed to the front frame 110 or disposed separately from the electronic device.

[0097] The display unit 300 can be implemented in the form of a head-mounted display (HMD). An HMD is a display mounted on the head and directly displays images in front of the user's eyes. When the user wears the electronic device, the display unit 300 can be configured to correspond to at least one of the left and right eyes, such that the image is presented directly in front of the user's eyes. The accompanying drawings show the display unit 300 located in the portion corresponding to the user's right eye, such that the image is output toward the right eye. However, as described above, the invention is not limited thereto, and the display unit 300 can be located on both the left and right eyes.

[0098] The display unit 300 allows users to visually perceive the external environment while simultaneously displaying images generated by the projection device 200. For example, the display unit 300 can use a prism to project images onto the display area.

[0099] Furthermore, the display unit 300 can be formed to be transparent, allowing the projected image and the general field of view (the range seen by the user through his / her eyes) to be viewed simultaneously. For example, the display unit 300 can be semi-transparent and can be formed from optical components including glass.

[0100] Furthermore, the display unit 300 can be inserted into and fixed in an opening included in the front frame 110, or it can be located on the rear surface of the opening (i.e., between the opening and the user) and fixed to the front frame 110. Although the accompanying drawings show, by way of example, the display unit 300 located on the rear surface of the opening and fixed to the front frame 110, the display unit 300 can be positioned and fixed at various locations on the frame 100.

[0101] like Figure 2 As shown, when the electronic device directs the image light from the image from the projection device 200 onto one side of the display unit 300, the image light is emitted through the display unit 300 to the other side, thereby allowing the user to see the image generated from the projection device 200.

[0102] Therefore, the user can see the external environment through the opening in the frame 100 and simultaneously see the image generated by the projection device 200. In other words, the image output by the display unit 300 can appear to overlap with the normal field of view. Electronic devices can use these display characteristics to provide augmented reality (AR), which overlays virtual images onto real-world images or backgrounds to create a single image.

[0103] In addition to the operations described above, the images generated from the external environment and the projection device 200 can be provided to the user with a short time difference that is imperceptible to humans. For example, in one frame, the external environment can be provided to the user in one segment, and the image from the projection device 200 can be provided to the user in another segment.

[0104] Alternatively, both overlay and time difference can be provided.

[0105] Furthermore, the projection device according to the embodiments may have the structure described below, or may be formed by a structure that further includes a waveguide and / or glass. Additionally, the projection device may include a digital light processing (DLP) projector or a projection apparatus.

[0106] Figure 3 This is a perspective view of the projection device according to an embodiment. Figure 4 This is another perspective view of the projection device according to an embodiment. Figure 5 This is an exploded perspective view of the projection device according to an embodiment. Figure 6 It is along Figure 3 The sectional view of line A-A' in the diagram.

[0107] refer to Figures 3 to 6The projection device 200 according to the embodiment may include a housing 210, a light source unit 220, a first lens 231, a second lens 232, a first reflector 251, a second reflector 252, a third lens 261, a fourth lens 262, a third reflector 253, a fifth lens 263, a prism 270, an optical modulator 280, a projection lens unit 290, and a blocking member TP.

[0108] The housing 210 may have a space or housing recess therein for accommodating or housing each component of the projection device 200. The housing 210 may be located outside the projection device 200. For example, the light source unit 220, the first lens 231, the second lens 232, the first reflector 251, the second reflector 252, the third lens 261, the fourth lens 262, the third reflector 253, the fifth lens 263, the prism 270, the optical modulator 280, and the projection lens unit 290 may be disposed in the housing 210.

[0109] Furthermore, the housing 210 may have a structure with an opening on one side. Therefore, each of the above-described components can be assembled through the opening area or surface. Additionally, the blocking member TP described below may be disposed in the opening area or surface of the housing 210.

[0110] The housing 210 can have various shapes. For example, the housing 210 can have a hexahedral structure. Therefore, the projection device according to the embodiment can be easily installed in an electronic device. Furthermore, the projection device according to the embodiment can be easily miniaturized or compacted.

[0111] The light source unit 220 can be disposed within the housing 210. The light source unit 220 can be disposed adjacent to any one of the outer surfaces of the housing 210.

[0112] The light source unit 220 may include at least one light source. In an embodiment, the light source unit 220 may include a first light source 221 and a second light source 222. The first light source 221 and the second light source 222 may be located near different surfaces in the housing 210. Furthermore, as described below, in an embodiment, the light source unit 220 may include only the first light source 221, the first light source 221 and the second light source 222, or the first light source 221 to the third light source.

[0113] Furthermore, multiple light sources can emit light of different wavelengths. As shown in the figure, when the light source unit 220 is composed of a first light source 221 and a second light source 222, the first light source 221 and the second light source 222 can emit light of different wavelengths or different colors. For example, the first light source 221 can emit light of green wavelength. For example, green wavelength light can be the center wavelength of the first light source 221. Furthermore, the second light source 222 can emit red and blue light. For example, red and blue light can be the center wavelength of the second light source 222.

[0114] Furthermore, in the projection device according to the embodiment, the first direction may correspond to the "X-axis direction" in the figures. The first direction may correspond to the direction from the first light source 221 toward the projection lens unit 290. Alternatively, the first direction may correspond to the direction from the first surface of the housing 210 toward the third surface. Furthermore, the second direction may correspond to the Y-axis direction in the figures. The second direction may be a direction perpendicular to the first direction. The third direction may be a direction perpendicular to both the first and second directions. Furthermore, the third direction may correspond to the "Z-axis direction" in the figures.

[0115] Furthermore, the first light source 221 and the second light source 222 in the light source unit 220 can emit light in parallel or different directions. In other words, the emission direction of light from the first light source 221 and the emission direction of light from the second light source 222 can be non-parallel to each other.

[0116] The lens unit 230 may be located at the rear end of the light source unit 220. The lens unit 230 may include at least one lens. For example, the lens unit 230 may include a first lens 231 and a second lens 232.

[0117] Furthermore, the first lens 231 and the second lens 232 can be disposed at the rear end of the light source unit 220. For example, the first lens 231 and the second lens 232 can be located at the rear end of each light source in the light source unit 220. For example, the first lens 231 and the second lens 232 can be sequentially disposed at the rear end of the first light source 221. Furthermore, the first lens 231 and the second lens 232 can be sequentially disposed at the rear end of the second light source 222. In the following description, the first lens 231 and the second lens 232 located at the rear end of the first light source 221 will be used. Furthermore, the following description can also be applied to the first lens 231 and the second lens 232 located at the rear end of the second light source 222 (or another light source).

[0118] Furthermore, the first lens (or second lens) adjacent to different light sources can be configured to be spaced apart from each other in the second direction, and at least a portion thereof can be configured to be offset in the first direction. For example, the spaced-apart first lenses 231 can be configured to be spaced apart from each other in the second direction (Y-axis direction). For example, at least a portion of the spaced-apart first lenses 231 can be configured to be offset in the first direction (X-axis direction). In other words, at least a portion of the spaced-apart first lenses 231 can not overlap in the first direction (Y-axis direction).

[0119] The first lens 231 can be positioned closer to the first light source 221 than the second lens 232. That is, the first lens 231 can be located between the second lens 232 and the first light source 221.

[0120] The first lens 231 can be configured such that light emitted from the first light source 221 is incident upon it. The first lens 231 can be located at the rear end of the first light source 221. In this embodiment, the rear end is described based on the direction of light travel emitted from the light source. Furthermore, light can be emitted from the light source and output to the outside through the projection lens unit 290. Therefore, the projection lens unit 290 can be located at the rear end of the light source unit.

[0121] Furthermore, light emitted from the first light source 221 can pass through the first lens 231. The first lens 231 can be located to one side of the first light source 221 in a first direction (X-axis direction). Alternatively, the first lens 231 can be located to one side of the first light source 221 along the light emission direction from the first light source 221.

[0122] Furthermore, the first lens 231 may overlap with the first light source 221 in a first direction (X-axis direction). Additionally, the second lens 232 may be configured such that light passing through the first lens 231 is incident upon it. The second lens 232 may be located at the rear end of the first lens 231. Furthermore, the second lens 232 may be located adjacent to the first lens 231. Light transmitted through the first lens 231 may be transmitted through or pass through the second lens 232.

[0123] The second lens 232 can overlap with the first light source 221 and the first lens 231 in the first direction (X-axis direction). Therefore, the first lens 231 and the second lens 232 can collect the light emitted from the first light source 221.

[0124] Furthermore, the first light source 221, the first lens 231, and the second lens 232 can be arranged sequentially based on the direction of light travel emitted from the first light source 221.

[0125] At least one of the first lens 231 and the second lens 232 can be a Fresnel lens or a lens including a metasurface. For example, the first lens 231 and the second lens 232 can be formed as Fresnel lenses. This will be the basis for the description below. Furthermore, this configuration can reduce the loss of light emitted from the light source unit (e.g., the first light source) and easily reduce the size of the projection device. This will be described in detail below.

[0126] The first reflecting mirror 251 and the second reflecting mirror 252 can be located at the rear end of the first lens 231 or the second lens 232. For example, the first reflecting mirror 251 and the second reflecting mirror 252 can be positioned on one side of the first light source 221 or the first lens 231 in a first direction (X-axis direction). Furthermore, the first reflecting mirror 251 and the second reflecting mirror 252 can be spaced apart from the first light source 221 or the first lens 231 in the first direction (X-axis direction). Moreover, light emitted from the first light source 221 (or the second light source) and light transmitted (or emitted) through the first lens 231 (or the second lens) can be transmitted through the first reflecting mirror 251 and the second reflecting mirror 252.

[0127] More specifically, light emitted from the first light source 221 and the first lens 231 can be transmitted through the first reflecting mirror 251. Furthermore, the second reflecting mirror 252 can reflect light emitted from the second light source 222 and the second lens 232. Additionally, light passing through the first reflecting mirror 251 can be transmitted through the second reflecting mirror 252. With this configuration, light emitted from the first light source 221 and the second light source 222 can be collected by the first lens unit and the second lens unit, and then incident on the third lens 261 at their rear ends. Therefore, the light required for optical modulation or image generation can be incident on the optical modulator 280.

[0128] Furthermore, the second reflector 252 may be disposed at the rear end of the first reflector 251. The first reflector 251 and the second reflector 252 may be tilted at a predetermined angle relative to the X-axis or Y-axis. Additionally, the first reflector 251 and the second reflector 252 may have different tilt angles relative to the X-axis or Y-axis.

[0129] Furthermore, the distance between one end of the first reflector 251 and the second reflector 252 may be different from the distance between their other ends. For example, the distance g1 between one end of the first reflector 251 and one end of the second reflector 252 may be different from the distance g2 between the other ends of the first reflector 251 and the second reflector 252. Moreover, the distance g1 between one end of the first reflector 251 and one end of the second reflector 252 may be smaller than the distance g2 between the other ends of the first reflector 251 and the second reflector 252.

[0130] Furthermore, the first reflector 251 and the second reflector 252 can have different lengths. For example, the first reflector 251 and the second reflector 252 can have different lengths in the XY plane. For example, the length of the second reflector located at the rear end can be greater than the length of the first reflector.

[0131] Furthermore, the first reflector 251 and the second reflector 252 may include dichroic mirrors. The first reflector 251 may include a dichroic mirror for red. The second reflector 252 may include a dichroic mirror for blue.

[0132] Furthermore, the first reflecting mirror 251 and the second reflecting mirror 252 can be implemented as prisms. For example, the first reflecting mirror 251 and the second reflecting mirror 252 can be implemented as an "X-cube". In this way, the first reflecting mirror 251 and the second reflecting mirror 252 can represent various mirror components used to reflect light incident in multiple directions to an exit surface or space.

[0133] The third lens 261 may be disposed at the rear end of the first reflector 251 and the second reflector 252. At least a portion of the third lens 261 may overlap with the first reflector 251 and the second reflector 252 in a first direction (X-axis direction). Furthermore, at least a portion of the third lens 261 may overlap with the first light source 221 and the first lens 231 in the first direction.

[0134] Light transmitted through the first reflecting mirror 251 and light reflected by the second reflecting mirror 252 can be transmitted through the third lens 261. For example, the third lens 261 may include a microlens array (MLA) to diffuse the collected light. That is, the third lens 261 may be a diffuser or a diffusion unit. Furthermore, the third lens 261 may include a compound eye lens (FEL). For example, the third lens 261 may be formed from an array of small lenses. Therefore, the third lens 261 can focus and converge light rays. In this way, the third lens 261 can focus light rays incident on an entire surface to a single point or small area, or it can diffuse light rays. In an embodiment, the third lens 261 can collect light rays. Furthermore, the third lens 261 can reflect or refract light rays or separate light rays of a specific wavelength depending on the surface and shape of each of the lenses.

[0135] Furthermore, the third lens 261 can be disposed between the second reflector 252 and the fourth lens 262. The second reflector 252 can be located at the front end of the third lens 261. Furthermore, the fourth lens 262 can be disposed at the rear end of the third lens 261. In this way, in this specification, each component of the projection device can be located between a component located at the front end and a component located at the rear end. For example, the third lens 261 can be located between at least one of the light source unit, the first lens unit, and the second lens unit, and at least one of the first and second reflectors, and at least one of the fourth lens, the third reflector, the fifth lens, the prism, the optical modulator, and the projection lens unit. Similarly, this positional relationship can be applied to other components in the same way.

[0136] The fourth lens 262 can be disposed at the rear end of the third lens 261. The fourth lens 262 can be disposed on one side of the third lens 261 in the first direction (X-axis direction). At least a portion of the fourth lens 262 can overlap with the third lens 261 in the first direction (X-axis direction). Similarly, at least a portion of the fourth lens 262 can also overlap with the first reflector 251, the second reflector 252, the first lens 231, and the first light source 221 in the first direction (X-axis direction). This configuration facilitates miniaturization of the projection device.

[0137] The fourth lens 262 may include a relay lens. Light emitted or transmitted through the third lens 261 can be transmitted through the fourth lens 262. The fourth lens 262 can transmit light from one location to another. In other words, the fourth lens 262 can arrange or change the path of light. Furthermore, the fourth lens 262 can adjust the size (maximum area of ​​light) or compensate for optical differences in the light or image provided by the illumination system.

[0138] The third reflecting mirror 253 can be located at the rear end of the fourth lens 262. The third reflecting mirror 253 can be located to one side of the fourth lens 262 in the first direction (X-axis direction). The third reflecting mirror 253 can be arranged to be spaced apart from the fourth lens 262 in the first direction. The third reflecting mirror 253 can be referred to as a "reflector".

[0139] Furthermore, the third reflecting mirror 253 can be tilted relative to the fourth lens 262 at a predetermined angle. The third reflecting mirror 253 can reflect light emitted from the fourth lens 262. For example, light passing through the fourth lens 262 can be reflected by the third reflecting mirror 253, thereby directing the light path toward the projection lens unit and then reflecting downwards.

[0140] The third reflecting mirror 253 can be tilted at a predetermined angle relative to the fourth lens 262, the first direction, etc. With this configuration, the projection device according to the embodiment can minimize its length in the second direction.

[0141] The fifth lens 263 may be disposed at the rear end of the third reflecting mirror 253. The fifth lens 263 may be disposed below the third reflecting mirror 253. At least a portion of the fifth lens 263 may overlap with the third reflecting mirror 253 in the second direction.

[0142] The fifth lens 263 may include a relay lens. Light reflected from the third mirror 253 can be transmitted through the fifth lens 263. The fifth lens 263 can transmit light from one location to another. That is, the fifth lens 263 can be arranged or altered to change the path of light. Furthermore, the fifth lens 263 can adjust the size (maximum light area) of the light or image provided by the illumination system or compensate for optical differences.

[0143] Furthermore, the fourth lens 262, the third reflector 253, and the fifth lens 263 can be arranged sequentially so that light emitted or transmitted through the first reflector 251 and the second reflector 252 is incident.

[0144] Furthermore, the exit surface of the fifth lens 263 can be located above the exit surface of the first lens 231. Additionally, the exit surface of the fifth lens 263 can be located above the exit surface of the second lens 232.

[0145] Prism 270 can be positioned at the rear end of fifth lens 263. Furthermore, prism 270 and fifth lens 263 can be arranged sequentially. Additionally, prism 270 can be located below fifth lens 263. Prism 270 and fifth lens 263 can partially overlap in the second direction. Furthermore, some areas of prism 270 may not overlap with fifth lens 263 in the second direction. With this configuration, light emitted (or transmitted) from fifth lens 263 can pass through prism 270, and the transmitted light can be incident on optical modulator 280 and reflected back to projection lens unit 290.

[0146] Prism 270 may include a total internal reflection prism (TIR prism). As described above, prism 270 can change the direction of light travel. That is, prism 270 can perform both transmission and reflection of light. Specifically, light emitted (or transmitted) from the fifth lens 263 can be transmitted through prism 270, and light emitted from the optical modulator 280 can be reflected by prism 270. Furthermore, light emitted from the light source unit 220 can be transmitted through prism 270, and prism 270 can reflect light emitted from the optical modulator 280. Therefore, the optical path can be redirected to the first direction or the projection lens unit. With this configuration, miniaturization of the projection device according to the embodiment can be achieved.

[0147] Prism 270 can be disposed between optical modulator 280 and projection lens unit 290. Alternatively, prism 270 can be disposed between fifth lens 263 and optical modulator 280.

[0148] An optical modulator 280 can be located at the rear end of the prism 270. The optical modulator 280 can reflect light transmitted through the prism 270 back into the prism 270.

[0149] Optical modulator 280 can project an image by reflecting incident light. For example, optical modulator 280 can transmit or project video or images based on an image signal input through board SB. That is, optical modulator 280 can modulate light emitted from light source unit 220.

[0150] The optical modulator 280 according to an embodiment may include a digital micromirror device (DMD). The optical modulator 280 may include a plurality of small mirrors. Furthermore, each mirror may reflect or block light based on a signal (e.g., a digital signal). In other words, the optical modulator 280 may control the state of each mirror based on an image signal applied via the board SB to project an image (or video) corresponding to the image signal. For example, when light is reflected by the control of the mirrors, a bright image area may be output, and when light is blocked, a dark image area may be output.

[0151] Furthermore, the second direction (Y-axis direction) can correspond to the vertical direction of the upper surface of the optical modulator 280.

[0152] The projection lens unit 290 can be disposed at the rear end of the prism 270. When light emitted from the optical modulator 280 is reflected by the prism 270, the reflected light can be incident on the projection lens unit 290. The light can then be projected from the projection lens unit 290. The projection lens unit 290 can project light emitted from the projection device onto a screen or waveguide (or display unit).

[0153] In an embodiment, the projection lens unit 290 can adjust the size of the image so that light is incident within the effective aperture diameter (incident pupil diameter, EPD) of the waveguide, etc.

[0154] Therefore, the projection lens unit 290 according to the embodiment may include a lens barrel 291 and a plurality of lenses L1 to L4 (or optical systems) disposed in the lens barrel.

[0155] At least a portion of the multiple lenses L1 to L4 may overlap with the prism 270 in the first direction.

[0156] A blocking member TP can be disposed on an outer surface of the housing 210. Therefore, after each component is housed in the housing 210, the blocking member TP can be disposed on the outside of each component. In an embodiment, the blocking member TP can be disposed on one side of the housing 210 to correspond to a recess in the housing 210. Furthermore, the blocking member TP can cover each component. With this configuration, the blocking member TP can easily block foreign objects or external light from entering the components of the housing 210. Therefore, image projection from electronic devices or projection devices can be achieved more accurately.

[0157] Furthermore, the projection device 200 according to the embodiment may include a plate SB, fastening members SC1, SC2 and SC3, and reinforcing plates ST1, ST2 and ST3.

[0158] The plate SB can be electrically connected to the light source unit 220 and the optical modulator 280. The light source unit 220 and the optical modulator 280 can be disposed on the plate SB. In addition, the plate SB can be disposed on the housing 210. For example, the plate SB can be disposed along the outer surface of the housing 210.

[0159] The operation of the optical modulator 280 and the light source unit 220 can be controlled via the board SB. The board SB can communicate with the control unit of an external device, etc., via wired or wireless means. For example, external control signals can be sent to the projection device via the board SB. Furthermore, the projection device can output an image based on the sent control signals.

[0160] Fastening components SC1, SC2, and SC3 can be disposed on the outer side of plate SB. This improves the coupling strength between plate SB, housing 210, light source unit 220, and optical modulator 280. Furthermore, plate SB can be disposed on the outer side of housing 210 to enhance assembly or design flexibility.

[0161] Reinforcing plates ST1, ST2, and ST3 can be disposed on the outer side of plate SB. Furthermore, reinforcing plates ST1, ST2, and ST3 can be made of various materials such as metal, composite materials, and resin (plastic) as reinforcing members. Reinforcing plates ST1, ST2, and ST3 can be disposed on the outer side of plate SB to improve the rigidity and strength of plate SB and the housing. For example, reinforcing plates ST1, ST2, and ST3 can be placed on plate SB to correspond to the positions of light source unit 220 and optical modulator 280. This configuration can suppress deformation caused by heat generated by light source unit 220 and optical modulator 280. Furthermore, reinforcing plates ST1, ST2, and ST3 can protect the projection device from external impacts, etc.

[0162] Fastening components SC1, SC2 and SC3 can pass through reinforcing plates ST1, ST2 and ST3.

[0163] For example, the fastening components may include a first fastening component SC1, a second fastening component SC2, and a third fastening component SC3. The reinforcing plate may include a first reinforcing plate ST1, a second reinforcing plate ST2, and a third reinforcing plate ST3.

[0164] The first fastening member SC1 and the first reinforcing plate ST1 can be positioned to correspond to the first light source 221. The first fastening member SC1 and the first reinforcing plate ST1 can overlap with the first light source 221 in a first direction.

[0165] The second fastening member SC2 and the second reinforcing plate ST2 can be positioned to correspond to the second light source 222. The second fastening member SC2 and the second reinforcing plate ST2 can overlap with the second light source 222 in a second direction.

[0166] The third fastening member SC3 and the third reinforcing plate ST3 can be positioned to correspond to the optical modulator 280. The third fastening member SC3 and the third reinforcing plate ST3 can overlap with the optical modulator 280 in the second direction (Y-axis direction).

[0167] Furthermore, each fastening member can pass through each reinforcing plate to improve the coupling strength between the plate and the housing 210. Additionally, a third fastening member SC3 can pass through the optical modulator 280 to improve the coupling strength between the optical modulator 280, the housing 210, and the plate SB.

[0168] As a modification example, the reinforcing plate can be formed integrally instead of multiple reinforcing plates to correspond to plate SB. That is, the reinforcing plate can have a structure that extends from the first light source 221 to the optical modulator 280.

[0169] Furthermore, each plate can also be configured to correspond to each light source and optical modulator. Additionally, fastening members can be disposed on each of the multiple plates. Alternatively, each of the fastening members can pass through all the plates in the multiple plates. Therefore, multiple plates can be coupled together using a single fastening member. Thus, the number of fastening members can be set to various odd or even numbers.

[0170] Figure 7 and Figure 8 This is a view of the projection device according to an embodiment, wherein the housing has been removed.

[0171] The projection device according to the embodiments may include an illumination system and a projection system (or a projection system, projection unit, projection component, projection component, etc.).

[0172] refer to Figure 7 The projection device may include an illumination system. According to an embodiment, the illumination system may include a housing 210, a light source unit 220, a first lens 231, a second lens 232, a first reflector 251, a second reflector 252, a third lens 261, a fourth lens 262, a third reflector 253, a fifth lens 263, and a prism 270. That is, light emitted from the prism 270 can be incident on the optical modulator 280.

[0173] The illumination system may include a prism 270 as a component, which receives light (illumination light) from a light source and emits light in a predetermined direction. The illumination light may be transmitted to or provided to an optical modulator 280 of the projection system.

[0174] Further reference Figure 8The projection system may include a prism 270, an optical modulator 280, and a projection lens unit 290. The projection system may include the prism 270 as a component. In an embodiment, the prism 270 may be a component of both the lighting system and the projection system. That is, the projection system may include components of the aforementioned lighting system.

[0175] Furthermore, the projection system can modulate the illumination light generated from the illumination system through the optical modulator 280, and emit or diffuse the light in a predetermined direction through the prism 270 and the projection lens unit 290.

[0176] In the projection system, the optical modulator 280 can reflect the illumination light into pattern light, and the pattern light can pass through the projection lens unit 290 and be output to the outside of the projection device.

[0177] Furthermore, the projection device may include a light source unit, an illumination system, an optical modulator, and a projection system. Therefore, the illumination system may include a first lens 231, a second lens 232, a first reflector 251, a second reflector 252, a third lens 261, a fourth lens 262, a third reflector 253, a fifth lens 263, and a prism 270. Furthermore, the projection system may include a prism 270 and a projection lens unit 290.

[0178] Furthermore, the optical folding component can be present between the output unit of the projection device and the input unit of the waveguide. The optical folding component can be configured to fold the optical path of patterned light along at least two different directions.

[0179] Figure 9 This is a cross-sectional view of the light source unit, first lens, second lens, first reflector, second reflector, and third lens in the projection device according to an embodiment. Figure 10 This is a cross-sectional view of the light source unit, first lens, second lens, first reflector, second reflector, and third lens in the projection device of the comparative example. Figure 11 This is a perspective view of the first lens or the second lens in the projection device according to an embodiment. Figure 12 This is a cross-sectional view of the first lens or the second lens in the projection device according to an embodiment, and Figure 13 This is another perspective view of the first lens or the second lens in the projection device according to the embodiment.

[0180] refer to Figure 9 and Figure 10 The projection device according to the embodiment may include a light source module, and the light source module may include a light source unit 220, a first lens 231, a second lens 232, a first reflector 251, a second reflector 252 and a third lens 261.

[0181] Furthermore, the projection device according to the comparative example also includes a light source module corresponding to the projection device according to the embodiment, but in the case of the comparative example, the first lens 213' and the second lens 232 of the light source module may be different from the first lens and the second lens according to the embodiment.

[0182] As described above, in the light source module of the projection device according to the embodiment, at least one of the plurality of light sources (i.e., the first lens 231 and the second lens 232) may include a Fresnel lens. For example, the first lens 231 and the second lens 232 may be formed as Fresnel lenses. With this configuration, the light beam can be easily focused in one place, and the spacing between the lenses can be reduced, thereby miniaturizing the projection device.

[0183] Furthermore, in the light source module of the projection device according to the comparative example, the first lens 231' and the second lens 232' can be formed as refractive lenses.

[0184] First, refer to Figures 11 to 13 In the projection device according to the embodiment, at least one of the first lens 231 and the second lens 232 may be a Fresnel lens. Although the following description is based on the first lens 231, the following description may also be applied to the second lens 232.

[0185] The first lens 231 may include multiple lens regions LR. Furthermore, multiple lens regions LR may be divided or defined within the first lens 231. The multiple lens regions LR may represent or correspond to unit regions of a pattern formed or arranged on the light source unit side surface S1 or the reflector side surface S2 of the first lens 231.

[0186] First, the first lens 231 may have a center. The center of the first lens 231 may correspond to the optical axis OX, the center of gravity, etc. In this embodiment, the center of the first lens 2231 may correspond to the optical axis OX.

[0187] The width W1 of each of the plurality of lens regions LR in the first lens 231 (or the second lens) can vary along the direction away from the center. For example, the width of each of the plurality of lens regions LR in the first lens 231 can decrease along the direction away from the center. Furthermore, among the plurality of lens regions LR, the width of the lens region LR that overlaps with the center or optical axis OX of the first lens 231 can be the largest. In addition, among the plurality of lens regions LR, the width of the lens region can increase towards the center of the first lens 231.

[0188] Furthermore, the maximum thickness of multiple lens regions LR can be the same. Therefore, the maximum thickness in a lens region LR can be the same as the maximum thickness of adjacent lens regions.

[0189] Furthermore, each of the plurality of lens regions LR according to the embodiment may include a plurality of sub-regions SR. That is, each lens region LR may be composed of a plurality of sub-regions SR.

[0190] Multiple sub-regions SR can be arranged adjacent to each other in a lens region LR. Furthermore, within a lens region LR, the multiple sub-regions SR can decrease in size as they move away from the center of the first lens 231. That is, the width W2 of each sub-region SR can decrease as it moves away from the center OX of the first lens 231.

[0191] Furthermore, the widths of sub-regions SR with the same thickness in adjacent lens regions LR can be different from each other. Additionally, the widths of sub-regions SR with the same thickness and spaced apart from each other in adjacent lens regions LR can decrease as they move further away from the center OX of the first lens 231.

[0192] Furthermore, in the accompanying drawings, the number of sub-regions SR within each lens region LR may be the same or different. That is, the number of multiple sub-regions SR is not limited to the number shown in the accompanying drawings.

[0193] Furthermore, in the first lens 231, the lens region LR on the light source unit side surface S1 and the lens region LR on the reflector side surface S2 can be positioned relative to each other along the optical axis. For example, the lens region LR on the light source unit side surface S1 and the lens region LR on the reflector side surface S2 can be formed symmetrically based on a surface that bisectes the first lens 231 along the optical axis. This configuration improves ease of manufacturing and enhances structural reliability.

[0194] Furthermore, the light source unit side surface S1 and the reflector side surface S2 of the first lens 231 can have different radii of curvature and optical performance levels. Therefore, the lens region LR on the light source unit side surface S1 and the lens region LR on the reflector side surface S2 of the first lens 231 can partially overlap along the optical axis. Furthermore, in the first lens 231, at least a portion of the lens region LR on the light source unit side surface S1 can be non-overlapping with the lens region LR on the reflector side surface S2 along the optical axis. For example, in the first lens 231, the nth adjacent pattern (lens region) starting from the center OX of the light source unit side surface S1 and the nth adjacent pattern (lens region) starting from the center OX of the reflector side surface S2 can be non-corresponding along the optical axis. Furthermore, in the first lens 231, at least a portion of the nth adjacent pattern (lens region) starting from the center OX of the light source unit side surface S1 can be non-overlapping with the nth adjacent pattern (lens region) starting from the center OX of the reflector side surface S2 along the optical axis. With this configuration, performance optimization, miniaturization, etc., can be easily achieved.

[0195] Furthermore, the maximum thickness of each of the multiple lens regions LR in the first lens 231 can also be different.

[0196] The volume (cubic centimeters, cc) of the light source module in the projection device can range from 1cc to 7cc. For example, the volume of the light source module can also vary depending on the size of the optical modulator, etc.

[0197] Furthermore, referring to Table 1 and other materials described below, the size of the light source module in the comparative example is 4.91cc. (24mm x 10mm x 19.5mm). The dimensions of the light source module in this embodiment are 3.03cc (17mm x 10.5mm x 17mm). In this way, as an effect, the projection device according to the embodiment can be easily miniaturized using the first and second lenses described above.

[0198] By miniaturizing the light source module through the use of the first lens 231 (or the second lens) described above, the projection device according to the embodiment can be designed and manufactured more compactly. Therefore, the projection device can be easily applied to wearable devices such as VR / AR / MR glasses, and user inconvenience caused by weight, etc., can also be resolved.

[0199] More specifically, Table 1 shows the relationship with Figure 9 and Figure 10 A table showing the size characteristics of the light source module and the size of the optical modulator in corresponding examples and comparative examples.

[0200] [Table 1]

[0201] Here, the thickness of the first and second lenses corresponds to their length along the optical axis, and the X-cube also corresponds to its thickness along the optical axis. Furthermore, the X-cube corresponds to the concept including the aforementioned first and second reflectors. Additionally, here, "third lens (MLA)" refers both to the case where the third lens is a microlens array (MLA) and to the case where a microlens array is added to the rear end of the X-cube in addition to the third lens. Referring to Table 1, the size of the optical modulator and the volume of the light source module according to the embodiment can have a ratio of 1:5 to 1:25. Here, the size of the optical modulator is in inches, and the volume is in cc. When the ratio is greater than 1:25, there is a limitation that miniaturization is difficult to achieve, and when the ratio is less than 1:5, there is a limitation that the manufacturing design is difficult. Table 2 below shows the characteristics of the components of the light source module in the comparative example, and Table 3 shows the characteristics of the components of the light source module in the embodiment. Furthermore, the thickness of the light source unit side surface of each lens refers to the thickness of the corresponding lens. Furthermore, the thickness of the reflector side surface of each lens refers to the spacing distance between the corresponding lens and the rear component. For example, referring to Table 3, the distance between the first lens and the second lens can be 1 mm. Furthermore, thickness and length can be expressed in mm.

[0202] [Table 2]

[0203] [Table 3]

[0204] Referring to Tables 1 and 2, the spacing between the first lens and the second lens in the projection device according to the embodiment can be similar to the thickness. For example, the spacing (or gap) between the first lens and the second lens can be 0.8 to 1.2 times the thickness of at least one of the first and second lenses. This configuration enables ease of manufacturing and miniaturization. Furthermore, the first lens and the second lens can have the same or similar thickness. In the embodiment, the thickness of the first lens can be 0.8 to 1.2 times the thickness of the second lens. This configuration enables easier lens manufacturing and a reduction in the thickness of the Fresnel lens. Additionally, in the embodiment, the light source unit side surface of the first lens can have the largest radius of curvature. The radius of curvature of the reflector side surface of the first lens can be greater than the radii of curvature of the light source unit side surface and the reflector side surface of the second lens.

[0205] Furthermore, the radius of curvature of the light source unit side surface and the radius of curvature of the reflector side surface of the second lens can have different signs. For example, the radius of curvature of the light source unit side surface of the second lens can have a negative sign, and the radius of curvature of the reflector side surface can have a positive sign. Therefore, the light source unit side surface of the second lens can bulge towards the reflector or be recessed towards the light source unit. Additionally, the reflector side surface of the second lens can bulge towards the light source unit. In this case, the radius of curvature can be the radius of curvature of the portion of the light source unit side surface (or reflector side surface) of each of the first and second lenses corresponding to the optical axis.

[0206] Figure 14 and Figure 15 This is a view illustrating the optical performance of a projection device according to comparative examples and embodiments.

[0207] Figure 14 and Figure 15 This is the result of geometric image analysis performed on the light source unit side surface of the first lens. Specifically, in Figure 14 A to Figure 15 In each of B, the X and Y axes of the left image represent the x-axis (horizontal position) and y-axis (vertical position), respectively. Furthermore, the Z-axis corresponds to the optical axis. Figure 14 and Figure 15 The analysis results are obtained by setting the field of view position to (0 [mm], 0 [mm]), the image size to 10 mm, and the pixel to 255×255.

[0208] refer to Figure 14 A, Figure 14 B. Figure 15 A and Figure 15 B. It can be seen that the optical performance of the light source module according to the embodiment is similar to that of the light source module according to the comparative example. Therefore, the projection device according to the embodiment can be easily miniaturized while maintaining optical performance.

[0209] Figure 16 This is a configuration diagram of the light source unit side in the projection device according to various examples of the embodiment.

[0210] As described above, the light source unit in the light source module of the projection device can consist of at least one light source.

[0211] like Figure 16 As shown in Figure A, the light source unit 220 in the projection device may include three light sources. For example, the light source unit 220 may include a first light source 221, a second light source 222, and a third light source 223. Furthermore, a first lens 231 and a second lens 232 may be disposed at the rear end of each light source.

[0212] In the comparative example, the first and second lenses in the light source module can be formed as refractive lenses. In this case, the volume of the light source module can be 4.8cc (24mm x 10mm x 20mm). Alternatively, in the embodiment, the volume of the light source module can be 3.06cc. (18mm x 10mm x 17mm).

[0213] refer to Figure 16 B. The light source unit 220 may consist of two light sources, and may include, for example, a first light source 221 and a second light source 222. Similarly, a first lens 231 and a second lens 232 may be disposed at the rear end of each light source.

[0214] In the comparative example, the first and second lenses in the light source module can be formed as refractive lenses, and the volume of the light source module according to the comparative example can be 3.4cc (17mm x 10mm x 20mm). Alternatively, in the embodiment, the volume of the light source module can be 2.38cc (14mm x 10mm x 17mm).

[0215] refer to Figure 16 C. The light source unit 220 may consist of a single light source and may include, for example, a first light source 221. Similarly, a first lens 231 and a second lens 232 may be disposed at the rear end of the first light source.

[0216] In the comparative example, the first and second lenses in the light source module can be formed as refractive lenses, and the volume of the light source module according to the comparative example can be 2cc (10mm x 10mm x 20mm). Alternatively, in the embodiment, the volume of the light source module can be 1.7cc (10mm x 10mm x 17mm).

[0217] In this way, as described above, the size of the light source module can be reduced according to the embodiment. Furthermore, the overall size of the projection device can also be reduced by decreasing the number of light sources in the projection device.

[0218] Figure 17 This is a cross-sectional view of the light source unit, first lens, second lens, first reflector, second reflector, and third lens in a projection device according to another embodiment. Figure 18 This is a schematic diagram of a metasurface applied to the rear end of a light source unit according to an embodiment. Figure 19 This is a schematic perspective view of a metasurface according to another embodiment. Figure 20 This is a schematic perspective view of a metasurface according to yet another embodiment. Figure 21 This is a schematic perspective view of a metasurface according to yet another embodiment. Figure 22 This is a schematic diagram of a metasurface according to yet another embodiment. Figure 23 This is a schematic diagram of a metasurface according to yet another embodiment. Figure 24 This is a schematic diagram of a metasurface according to yet another embodiment.

[0219] refer to Figure 17 and Figure 18 A projection device according to another embodiment can be used in the same manner as the projection device described above. For example, a projection device according to another embodiment may include a housing, a light source unit 220, a first lens 231, a second lens 232, a first reflector 251, a second reflector 252, a third lens 261, a fourth lens, a third reflector, a fifth lens, a prism, an optical modulator, a projection lens unit, and a blocking member. Furthermore, the projection device may include other components as described above, and optically includes an illumination system and a projection system. It should also be understood that other embodiments or the above-described contents may be applied in addition to those described below.

[0220] Furthermore, the projection device described below can have a metasurface. The metasurface can be located at the rear end of the light source unit. For example, the metasurface can be located on the first lens, second lens, or front prism (the aforementioned X cube) at the rear end of the light source unit.

[0221] Specifically, in the projection device according to the embodiment, at least one of the first lens 231 and the second lens 232 may have a first metasurface. Through this first metasurface, the first lens and the second lens can be arranged in a similar size and position to the Fresnel lens described above. That is, the volume and size of the light source module can be kept relatively small.

[0222] The first metasurface may be located on at least one of the light source unit side surface and the reflector side surface of the first lens 231 and the second lens 232. In the following description, the light source unit side surface of the first lens 231 will be used as the basis.

[0223] The first metasurface MF1 can be arranged to form a shape distribution that modulates the phase of the incident light according to a predetermined rule depending on the location. Furthermore, the first metasurface MF1 may include multiple structures MS having dimensions (e.g., width D, thickness t, etc.) for shapes according to sub-wavelengths. Here, a sub-wavelength refers to a wavelength smaller than the incident light, which may be the target of phase modulation.

[0224] For example, in the first metasurface MF1, at least one of the dimensions of the shape (such as width and thickness) may correspond to a sub-wavelength. That is, the first metasurface MF may include a plurality of patterned structures MS having a width or thickness smaller than the wavelength of the incident light.

[0225] Furthermore, the distance between the centers of adjacent structures MS can be represented as a spacing P, which can also be a sub-wavelength or correspond to a sub-wavelength.

[0226] The width D, thickness t, and spacing P of multiple structured MSs can be arranged according to predetermined rules determined by their positions. Furthermore, multiple structured MSs can be formed in an array. For example, a structured array PMS of multiple structures can be determined based on a desired predetermined phase modulation pattern for light in a desired wavelength band. For example, the wavelength band can be in the range of 300 nm to 1000 nm, 400 nm to 750 nm, or 700 nm to 1000 nm. This can be set in response to the color of the light described above.

[0227] Each of the multiple structural MSs can be formed on a substrate BS. The substrate BS can be made of a material with a refractive index lower than that of the structural MSs. Furthermore, a protective layer PL covering the multiple structural MSs can be formed on the substrate BS. The protective layer PL can be formed of a material with a refractive index lower than that of the structural MSs. The protective layer PL can also be made of a material with the same refractive index as the substrate BS. The protective layer PL can be made of a light-transmitting material. Alternatively, the protective layer PL can be omitted.

[0228] The structured MS can be made of a material with a refractive index higher than that of the substrate BS, and this can improve the modulation efficiency of the modulated incident light. In other words, by controlling the shape, distribution, arrangement, etc., of the structured array PMS, the range of phase modulation can be easily expanded. Furthermore, this phase modulation can occur in the form of a transmitted phase. Therefore, when the loss is high (high absorption rate), i.e., when the extinction coefficient k is large, the optical efficiency of the modulated light may decrease. The structured MS according to the embodiment can widen the modulation range and improve the optical efficiency, thereby modulating light into various desired forms.

[0229] refer to Figure 19 The structure MS can have a polygonal prism shape. However, the invention is not limited to this, and the structure MS can have an elliptical cylinder shape or various polygonal prism shapes.

[0230] Furthermore, a structure MS can be formed by arranging cylinders or polygonal columns of various diameters or widths at appropriate locations to create a structure array PMS. A structure array PMS composed of multiple structures can have a periodic arrangement, a quasi-periodic arrangement, a random arrangement, or a quasi-random arrangement.

[0231] refer to Figure 20 As an example, the first metasurface may include a structure array PMS in which strip structures MS are arranged one-dimensionally. The width D of the strip shapes is shown as constant, but may vary depending on their position.

[0232] refer to Figure 21As another example, the structure MS in the first metasurface differs from the first metasurface described above in that it has a sculpted cylindrical shape. That is, although the structure MS is implemented in relief form in the above embodiments, the structure can also be implemented in sculpted form, for example, a hole structure.

[0233] For example, the aforementioned structure MS can be formed on a substrate BS. Specifically, the structure MS can consist of multiple engraved cavities CV (or holes or grooves). Therefore, the first metasurface can be formed in various shapes, such as slits, grooves, and holes. The cavities CV are depicted as having a cylindrical shape, but are not limited to this, and can have an elliptical cylindrical shape, a polygonal prism shape, or a strip shape. It should also be understood that in other embodiments, the structure can be implemented in the form of relief or engraving.

[0234] refer to Figure 22 As yet another example, the first metasurface may include a structure array PMS, wherein the structures MS are arranged to function as convex lenses.

[0235] The structure array PMS can have an array form in which the width D of each structure MS gradually decreases from the center to the periphery.

[0236] Furthermore, the array configuration can be a structure that repeats at least once from the center of the first metasurface or substrate BS outwards or outwards. Additionally, the convexity (positive diopter) can be adjusted by controlling the tendency to change the width D, the number of repeated patterns (or regions), etc.

[0237] refer to Figure 23 As yet another example, the first metasurface includes a structure array PMS, wherein the structures MS are arranged to function as concave lenses.

[0238] The structure array PMS can have an arrangement in which the width D of the structure MS gradually increases from the center to the periphery.

[0239] Furthermore, this form can be a structure that repeats at least once from the center of the first metasurface or substrate BS outwards or outwards. Additionally, the concavity (negative refractive power) can be adjusted by controlling the tendency to change the width D, the number of repeated patterns (or regions), etc.

[0240] refer to Figure 24 The structure array PMS can have a structure MS, the width D of which varies from the center to the periphery, and its shape can also vary. That is, the shapes of the structures according to the various examples above can be combined and implemented.

[0241] For example, structure MS may include a first structure MS1 and a second structure MS2. The first structure MS1 and the second structure MS2 may have different shapes, and the width and thickness of the first structure MS1 and the second structure MS2 may be the same or different. In addition, the arrangement orientation of the first structure MS1 and the second structure MS2 may also be different.

[0242] Figure 25 This is a cross-sectional view of the light source unit, first lens, second lens, first reflector, second reflector, and third lens in a projection device according to yet another embodiment. Figure 26 This is an exploded perspective view showing a first reflector, a second reflector, and a metasurface in a projection device according to yet another embodiment.

[0243] refer to Figure 25 and Figure 26 The projection device according to another embodiment can be used in the same manner as the projection device described above. For example, the projection device according to another embodiment may include a housing, a light source unit 220, a first lens 231, a second lens 232, a first reflector 251, a second reflector 252, a third lens 261, a fourth lens, a third reflector, a fifth lens, a prism, an optical modulator, a projection lens unit, and a blocking member. Furthermore, the projection device may include other components as described above, and optically it may consist of an illumination system and a projection system. Moreover, it should be understood that other embodiments or the above-described contents may be applied in addition to those described below.

[0244] Furthermore, the projection device described below can have a metasurface. The metasurface can be located at the rear end of the light source unit. For example, the metasurface can be located on the front prism (the aforementioned X cube) at the rear end of the first lens, the second lens, or the light source unit.

[0245] Specifically, in this embodiment, the metasurface may be located between the light source unit and the reflector. Furthermore, the metasurface may be located between the second lens and the reflector. In particular, the metasurface may be located on the front prism to correspond to the first and second reflectors. For example, the front prism may be formed of a prism, such as an x-cube as described above.

[0246] The front prism PP may include: an incident surface facing the light source unit (or each light source); and an exit surface through which light incident on the incident surface is reflected and then exited. Furthermore, the front prism PP may include a second metasurface MF2 located on the incident surface. The second metasurface MF2 may be formed directly on the outer surface of the front prism. Alternatively, the metasurface MF2 may be formed from a wafer or the like, and the second metasurface MF2 may be disposed on the outer surface of the front prism by means of an adhesive member or the like.

[0247] Specifically, the outer surface of the front prism PP may include a first outer surface SF1 to a third outer surface SF3 facing the light sources 221, 222, and 223, respectively. The first outer surface SF1 may face the first light source 221. The second outer surface SF2 may face the second light source 222. The third outer surface SF3 may face the third light source 223. Alternatively, the first light source 221 may correspond to the first outer surface SF1. The second light source 222 may correspond to the second outer surface SF2. The third light source 223 may correspond to the third outer surface SF3.

[0248] Furthermore, the outer surface of the front prism PP may include a fourth outer surface SF4. The fourth outer surface SF4 may be the outer surface of the front prism PP facing the third lens MLA. That is, the fourth outer surface SF4 may correspond to the third lens.

[0249] Furthermore, the first outer surface SF1 and the fourth outer surface SF4 can be opposing surfaces of the front prism PP. For example, in the front prism PP, the first outer surface SF1 and the fourth outer surface SF4 can be positioned corresponding to each other. In the front prism PP, the first outer surface SF1 and the fourth outer surface SF4 can overlap in one direction. In the front prism PP, the first outer surface SF1 and the fourth outer surface SF4 can be surfaces facing each other.

[0250] The second outer surface SF2 and the third outer surface SF3 can be opposing surfaces of the front prism PP. For example, in the front prism PP, the second outer surface SF2 and the third outer surface SF3 can be positioned corresponding to each other. In the front prism PP, the second outer surface SF2 and the third outer surface SF3 can overlap in different directions. In the front prism PP, the second outer surface SF2 and the third outer surface SF3 can be surfaces facing each other.

[0251] In addition, the outer surface may include a fifth outer surface and a sixth outer surface. The fifth and sixth outer surfaces may be the outer surfaces of the front prism PP other than the first outer surface SF1 to the fourth outer surface SF4.

[0252] Furthermore, the projection device may include a second metasurface MF2 located between the front prism PP and each light source. Therefore, the second metasurface MF2 can contact the front prism PP.

[0253] The second metasurface MF2 may be located on each of the first to third outer surfaces, or it may be integrally located on the first to third outer surfaces. The second metasurface MF2 may have the same structure as the first metasurface described above.

[0254] In other words, the second metasurface MF2 can be arranged to form a shape distribution that modulates the phase of the incident light according to a predetermined rule depending on the position. Furthermore, the second metasurface MF2 may include multiple structures MS having dimensions (e.g., width D, thickness t, etc.) for shapes according to sub-wavelengths. Here, a sub-wavelength refers to a wavelength smaller than the incident light, which can be the target of phase modulation.

[0255] For example, in the second metasurface MF2, at least one of the width and thickness, which are dimensions of the shape, can correspond to a sub-wavelength. That is, the second metasurface MF can include multiple patterned structures MS having a width or thickness smaller than the wavelength of the incident light.

[0256] Furthermore, the distance between the centers of adjacent structures MS can be expressed as a spacing P, and this spacing P can also be a sub-wavelength or correspond to a sub-wavelength.

[0257] The width D, thickness t, and spacing P of multiple structured MSs can be arranged according to predetermined rules determined by their positions. Furthermore, multiple structured MSs can be formed in an array. For example, a structured array PMS in the array form of multiple structures can be determined based on a desired predetermined phase modulation pattern for light in a desired wavelength band. The content of the first metasurface described below can also be applied to the second metasurface in the same way.

[0258] Furthermore, as a modification example, the metasurface can be located on the first lens, second lens, or front prism (the aforementioned X-cube) at the rear end of the light source unit, and at least one of the first and second lenses can be formed as a Fresnel lens. For example, one of the first and second lenses can be formed as a Fresnel lens, and the other can include a metasurface. Furthermore, as another example, the first and second lenses can be formed as Fresnel lenses, and the front prism can include a metasurface. That is, the metasurface can be formed on one of the first and second lenses, and replaced by a Fresnel lens.

[0259] The features, structures, effects, etc., described in the above embodiments are included in at least one embodiment, and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, etc., exemplified in each embodiment can be combined or modified by those skilled in the art to which the embodiments pertain and implemented in other embodiments. Therefore, content related to these combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0260] While the foregoing description has been centered on examples, these are merely illustrative and do not limit the invention. Those skilled in the art will recognize that various modifications and applications, not illustrated above, can be made without departing from the essential characteristics of these examples. For instance, each component specifically shown in the examples can be modified and implemented. Furthermore, differences relating to these modifications and applications should be interpreted as including within the scope of the invention as defined in the appended claims.

Claims

1. A projection device, comprising: Light source unit; An optical modulator is configured to modulate light emitted from the light source unit; A prism is disposed between the optical modulator and the light source unit; A reflective element is disposed between the optical modulator and the prism; A first lens is disposed between the prism and the light source unit; as well as The second lens is disposed between the first lens and the prism. The interval between the first lens and the second lens is 0.8 to 1.2 times the thickness of at least one of the first lens and the second lens.

2. The projection device according to claim 1, wherein, The ratio of the size of the optical modulator to the total volume of the light source unit, the first lens, and the second lens is in the range of 1:5 to 1:25 (inches:cc).

3. The projection device according to claim 1, wherein, At least one of the first lens and the second lens is a Fresnel lens.

4. The projection device according to claim 3, wherein, The first lens and the second lens are Fresnel lenses. Each of the first lens and the second lens includes a plurality of lens regions, and The width of each of the plurality of lens regions decreases in a direction away from the center of each of the first lens and the second lens.

5. The projection device according to claim 4, wherein, Each of the lens regions includes multiple sub-regions, and The width of each sub-region decreases in a direction away from the center of each of the first and second lenses.

6. The projection device according to claim 5, wherein, Multiple sub-regions correspond to each other on each of the light source unit side surface and the reflector side surface of the first lens.

7. The projection device according to claim 1, wherein, The first lens and the second lens have the same thickness.

8. The projection device according to claim 1, wherein, The distance between the first lens and the second lens is the same as the thickness of the first lens or the second lens.

9. The projection device according to claim 1, wherein, In the first lens and the second lens, the light source unit side surface of the first lens has the largest radius of curvature.

10. The projection device according to claim 1, wherein, In the second lens, the radius of curvature of the light source unit side surface and the radius of curvature of the reflector side surface have different signs.

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