Optical module and projection device

Abstract

The invention provides an optical module and a projection device. The optical module comprises a light source and an optical structure. The light source is used for emitting light, and the optical structure is arranged on the light source and used for receiving the light. The optical structure includes a first surface and a second surface. The first surface is configured to deflect light. The second surface is configured to project a predetermined pattern when light passes through the second surface, the second surface is provided with a plurality of microstructures, and the second surface corresponds to the first surface.

Description

Technical Field

[0001] The present invention relates to an optical module, and more particularly to an optical module including an optical structure having two surfaces with different functions and a projection device to which the optical module is applied. Background Art

[0002] Projectors for projecting patterns are widely used in three-dimensional (3D) sensing systems, in which patterns can be projected through optical elements. However, in existing projectors, in order to project a pattern with a large field of view (FOV), the structural shape of the optical element needs to have a large slope at the same time, resulting in difficulties in the process of the optical element. In addition, optical elements with defective structures and / or zero-order emitted light can cause human eye safety problems. Summary of the Invention

[0003] One object of the present invention is to provide an optical module and a projection device to which the optical module is applied to improve the problems encountered by existing projection devices. The provided optical module includes a first surface configured to deflect light and a second surface configured to project a predetermined pattern, so that the optical module can have a large projection field of view and the size of the optical module is small.

[0004] An embodiment of the present invention provides an optical module. The optical module includes a light source and an optical structure. The light source is used to emit light, and the optical structure is disposed on the light source and used to receive light. The optical structure includes a first surface and a second surface. The first surface is configured to deflect light. The second surface is configured to project a predetermined pattern when light passes through the second surface, and the second surface has a plurality of microstructures, wherein the second surface corresponds to the first surface.

[0005] An embodiment of the present invention provides a projection device. The projection device includes at least two of the above optical modules. At least two optical modules are disposed adjacent to each other, and the predetermined patterns projected by the at least two optical modules are combined to form a design pattern.

[0006] The beneficial effects of the present invention are that, according to the optical module and the projection device to which the optical module is applied according to the embodiments of the present invention, through the structural design of the optical module including the first surface configured to deflect light and the second surface configured to project a predetermined pattern, the optical module can have a large projection field of view and can reduce human eye safety problems. In addition, by deflecting different traveling directions of light, two or more small-size patterns can be combined to form and project a large pattern. Brief Description of the Drawings

[0007] Figure 1 A schematic diagram of the optical module according to the first embodiment of the present invention.

[0008] Figure 2 Schematic diagram of an optical module according to a variant embodiment of the first embodiment of the present invention.

[0009] Figure 3 Schematic diagram of an optical module according to the second embodiment of the present invention.

[0010] Figure 4 Schematic diagram of a projection device including two optical modules according to another embodiment of the present invention.

[0011] Figure 5 It is from Figure 4 Schematic diagram of a design pattern projected by the projection device shown.

[0012] The reference numerals are as follows:

[0013] 100: Optical module

[0014] 110: Light source

[0015] 120: Optical structure

[0016] 122: Microstructure

[0017] 130: Light-shielding element

[0018] 132: Opening

[0019] CE: Connecting element

[0020] DPA: Design pattern

[0021] EF: Emission range

[0022] L, La, Lb: Light rays

[0023] L0, L0a, L0b: Deflected light

[0024] L1: First deflected light

[0025] L2: Second deflected light

[0026] LS: Stray light

[0027] OL1: First optical layer

[0028] OL2: Second optical layer

[0029] P1: First part

[0030] P2: Second part

[0031] PA: Predetermined pattern

[0032] PA1: First sub-pattern

[0033] PA2: Second sub-pattern

[0034] PF: Projection range

[0035] PRO: Projection device

[0036] S1: First surface

[0037] S2: Second surface

[0038] SB: Substrate

[0039] SB1: First substrate

[0040] SB2: Second substrate

[0041] Z: Direction

[0042] θa, θb: Included angle Detailed implementation manners

[0043] The content of the present invention will be described in detail below in combination with specific embodiments and the accompanying drawings. It should be noted that, in order to enable readers to easily understand and for the simplicity of the drawings, only at least a part of the optical module and / or the projection device is drawn in multiple drawings of the present invention, and specific elements in the drawings are not drawn according to the actual ratio. In addition, the number and size of each element in the drawings are only for illustration and are not used to limit the scope of the present invention.

[0044] Throughout the specification and claims of the present invention, certain terms will be used to refer to specific elements. Those skilled in the art should understand that equipment manufacturers may use different names to refer to the same element. This document does not intend to distinguish elements that have the same function but different names. In the following specification and claims, words such as "comprising", "including" and "having" are open-ended terms, and thus should be interpreted as meaning "including but not limited to...". When the terms "comprise", "include", "contain" and / or "have" are used in this specification, they specify the presence of the described features, regions, steps, operations and / or elements, but do not exclude the presence or addition of one or more other features, regions, steps, operations, elements and / or their combinations.

[0045] When an element or film layer is referred to as being "on" or "connected to" another element or film layer, it can be directly on this other element or film layer or directly connected to this other element or film layer, or there are intervening elements or film layers between them (i.e., indirectly connected). Conversely, when an element is referred to as being "directly" on another element or film layer or "directly connected to" another element or film layer, there are no intervening elements or film layers between them.

[0046] The directional terms mentioned in this text, such as "up", "down", "front", "back", "left", "right", etc., are only with reference to the directions in the accompanying drawings. Therefore, the directional terms used are for illustration purposes and not for limiting the present invention.

[0047] The ordinal numbers used in the description and claims, such as "first", "second", etc., are used to modify elements. They do not themselves imply or represent that the element(s) have any previous ordinal number, nor do they represent the order of one element relative to another element or the order in the manufacturing method. The use of multiple ordinal numbers is only to clearly distinguish an element with a certain name from another element with the same name. The claims and the description may not use the same terms. Accordingly, the first component in the description may be the second component in the claims.

[0048] It should be noted that, without departing from the spirit of the present invention, the features in several different embodiments can be replaced, reorganized, and mixed to complete other embodiments.

[0049] Please refer to Figure 1 , which is a schematic diagram of the optical module according to the first embodiment of the present invention. As Figure 1As shown, the optical module 100 of the present invention includes a light source 110 and an optical structure 120. The light source 110 is used to emit light rays L, and the optical structure 120 is disposed on the light source 110 and is used to receive the light rays L. The light source 110 may include one of a laser diode (LD), a vertical-cavity surface-emitting laser (VCSEL), a light-emitting diode (LED), and a photonic-crystal surface-emitting laser (PCSEL), or the light source 110 may include other suitable light-emitting elements, not limited to the above. The optical structure 120 includes a first surface S1 and a second surface S2, and the second surface S2 corresponds to the first surface S1. The first surface S1 is configured to deflect the light rays L, and the second surface S2 is configured to project a predetermined pattern PA when the deflected light of the light rays L passes through the second surface S2, and the second surface S2 has a plurality of microstructures 122. For example, the first surface S1 may be formed by a first optical layer OL1 including a deflection element for deflecting light, and the second surface S2 may be formed by a second optical layer OL2 having a plurality of microstructures 122. The first surface S1 may include an inclined surface, a blazed grating, a prism, or a prism array. The plurality of microstructures 122 of the second surface S2 may form a micro lens array (MLA), a diffractive optical element (DOE), or meta-surfaces. According to an embodiment of the present invention, one or more optical modules 100 may be applied to a projection device to project one or more predetermined patterns PA. The projection device may include a flood illuminator, a dot projector, or a combination of the above, and the projection device may be applied to a three-dimensional sensing system or a vehicle sensing device, but not limited thereto.

[0050] As Figure 1 shown, the first surface S1 may be disposed between the second surface S2 and the light source 110, and the light rays L are deflected by the first surface S1 and then pass through the second surface S2. However, the positions of the first surface S1 and the second surface S2 are not limited to the above, and they may be interchanged with each other in other embodiments (not shown in the figure), that is, the second surface S2 may be disposed between the first surface S1 and the light source 110, and the light rays L are deflected by the first surface S1 after passing through the second surface S2.

[0051] According Figure 1In the illustrated embodiment, the optical structure 120 may include a substrate SB, and a first surface S1 and a second surface S2 are located on opposite sides of the substrate SB. Specifically, the first optical layer OL1 may be disposed on the side of the substrate SB facing the light source 110, that is, on the lower surface of the substrate SB, and the second optical layer OL2 may be disposed on the other side of the substrate SB facing away from the light source 110, that is, on the upper surface of the substrate SB, such that the first surface S1 faces the light source 110 and the second surface S2 faces away from the light source 110. The light source 110 emits light rays L, and the light rays L enter the first surface S1 and are deflected by the first optical layer OL1 on the first surface S1 into deflected light rays L0. Then, the deflected light rays L0 pass through the substrate SB to enter the second optical layer OL2 on the second surface S2 and are projected into a predetermined pattern PA. However, the structural design of the optical structure 120 is not limited to the above. In other embodiments, the second optical layer OL2 may be disposed on the side of the substrate SB facing the light source 110 to make the second surface S2 face the light source 110, and the first optical layer OL1 may be disposed on the other side of the substrate SB facing away from the light source 110 to make the first surface S1 face away from the light source 110.

[0052] As Figure 1 shown, the light source 110 emits light rays L having an emission range EF, and the emission range EF is represented by a dashed line between the light source 110 and the first surface S1. The emission range EF represents the initial propagation field of the light rays L emitted by the light source 110. The dashed line of the emission range EF also shows the outermost light rays of the initial light rays L emitted by the light source 110. After the light rays L pass through the first surface S1 and are deflected by the first surface S1, the traveling direction of the light rays L changes, where the light rays L are deflected into deflected light rays L0. After the deflected light rays L0 pass through the second surface S2, the propagation range or light profile of the deflected light rays L0 becomes a projection range PF, and the projection range PF represents the final projection range of the optical module 100 or the projection device to which it is applied. The traveling direction of the outermost light rays of the deflected light rays L0 shown by the dashed line of the projection range PF changes to have a larger exit angle with respect to the normal direction of the substrate SB, thereby having a larger projection range PF. In other words, the first surface S1 changes the traveling path and / or traveling direction of the light rays L emitted by the light source 110, and after the deflected light rays L0 pass through the second surface S2, a larger final field of view generated by the optical module 100 can be obtained, which produces a larger predetermined pattern PA.

[0053] With the above structural design, since the first surface S1 provides a deflection function and the light ray L emitted by the light source 110 can be deflected, and the second surface S2 provides a larger propagation range or light shape for the deflected light L0, the predetermined pattern PA projected by the optical module 100 can have a larger projection field of view. On the other hand, the second surface S2 configured to project the predetermined pattern PA but not requiring deflection of the light ray can have a smaller size, which can simplify the design of the second surface S2.

[0054] Please refer to Figure 2 , which is a schematic diagram of an optical module according to a variant embodiment of the first embodiment of the present invention. As Figure 2 shown, the optical module 100 may further include a light-shielding element 130, surrounding the light source 110 and the optical structure 120. The optical module 100 and the light-shielding element 130 can be applied together to the projection device PRO. The light-shielding element 130 has an opening 132, and the light ray L deflected by the first surface S1 can pass through the opening 132. That is to say, the deflected light L0 (or most of the deflected light L0) will not be blocked by the light-shielding element 130 and can pass through the opening 132 to form a predetermined pattern PA. Moreover, the light-shielding element 130 can block stray light. Specifically, since the light ray L is deflected, the light ray (i.e., the zero-order light ray) in the traveling direction Z can be reduced, and the stray light LS that is not deflected and has the traveling direction Z can be blocked by the light-shielding element 130, thereby reducing the human eye safety problem caused by the zero-order light ray. According to Figure 2 the embodiment shown, the direction Z can be parallel to the initial traveling direction of the light ray L emitted by the light source 110, and the direction Z can be, for example, perpendicular to the upper surface or the lower surface of the substrate SB, but is not limited thereto.

[0055] Please refer to Figure 3 , which is a schematic diagram of an optical module according to a second embodiment of the present invention. Figure 3 The difference between the optical module 100 of the second embodiment shown and the first embodiment is that the optical structure 120 may include a first substrate SB1 and a second substrate SB2. The second substrate SB2 corresponds to the first substrate SB1. The first surface S1 is located on one side of the first substrate SB1, and the second surface S2 is located on one side of the second substrate SB2. In some embodiments, the optical structure 120 may further include a connecting element CE, and the first substrate SB1 is connected to the second substrate SB2 through the connecting element CE, where the connecting element CE can be, for example (but not limited to), a bonding pad, glue, or other suitable elements capable of connecting the first substrate SB1 and the second substrate SB2.

[0056] According to Figure 3In the illustrated embodiment, the first optical layer OL1 can be disposed on a side of the first substrate SB1 facing the light source 110, and the second optical layer OL2 can be disposed on a side of the second substrate SB2 facing the light source 110, such that the first surface S1 faces the light source 110 and the second surface S2 faces the light source 110. However, the structural design of the optical structure 120 is not limited thereto. In the optical structure 120 of the optical module 100 of the present invention, the first optical layer OL1 can be disposed on a side of the first substrate SB1 facing or facing away from the light source 110, and the second optical layer OL2 can be disposed on a side of the second substrate SB2 facing or facing away from the light source 110.

[0057] As Figure 3 shown, the light source 110 can emit light rays L, and the light rays L enter the first surface S1 and are deflected by the first optical layer OL1 of the first surface S1 into a first deflected light ray L1 and a second deflected light ray L2, wherein the traveling direction of the first deflected light ray L1 is different from the traveling direction of the second deflected light ray L2. For example, the light rays L can travel to different parts of the first surface S1 and are respectively deflected by different parts of the first surface S1 into a first deflected light ray L1 and a second deflected light ray L2. The first deflected light ray L1 passes through a first part P1 of the second surface S2 formed by the second optical layer OL2 to form a first sub-pattern PA1, and the second deflected light ray L2 passes through a second part P2 of the second surface S2 formed by the second optical layer OL2 to form a second sub-pattern PA2, wherein the first sub-pattern PA1 and the second sub-pattern PA2 are combined to form a predetermined pattern PA. The first part P1 is not the same as the second part P2, that is to say, the first part P1 can at least partially not overlap with the second part P2. In Figure 3 the illustrated embodiment, the first part P1 partially overlaps with the second part P2. In a variant embodiment, the first part P1 can completely not overlap with the second part P2.

[0058] Through the above structural design of the optical module 100, the optical module 100 can have a large-size projection field of view, and can form and project a large-size predetermined pattern PA by combining two or more small-size sub-patterns projected simultaneously. In some embodiments, multiple sub-patterns (such as the first sub-pattern PA1 and the second sub-pattern PA2) can be projected by a time-division multiplexing method, rather than being projected simultaneously, but not limited thereto.

[0059] Please refer to Figure 4 and Figure 5 . Figure 4 FIG. is a schematic diagram of a projection device including two optical modules according to another embodiment of the present invention. Figure 5 is a schematic diagram of a design pattern projected by the projection device shown in Figure 4 . As Figure 4 and Figure 5As shown, multiple optical modules 100 of various embodiments of the present invention can be arranged adjacent to each other to form a projection device PRO. For example, the projection device PRO can include two optical modules 100 arranged adjacent to each other, and the predetermined patterns PA projected by the two optical modules 100 are combined to form a design pattern DPA. According to Figure 4 and Figure 5 the embodiment shown, the optical structure 120 of each of the two optical modules 100 can include a first substrate SB1 and a second substrate SB2 corresponding to the first substrate SB1. A first optical layer OL1 can be disposed on a side of the first substrate SB1 facing away from the light source 110, and a second optical layer OL2 can be disposed on a side of the second substrate SB2 facing the light source 110, such that the first surface S1 faces away from the light source 110 and the second surface S2 faces the light source 110. In other words, the first optical layer OL1 and the second optical layer OL2 can both be disposed between the first substrate SB1 and the second substrate SB2, such that the first surface S1 and the second surface S2 are both located between the first substrate SB1 and the second substrate SB2. However, the structural design of the optical structure 120 in the two optical modules 100 is not limited to the above. In the optical structure 120 of each optical module 100 of the projection device PRO of the present invention, the first optical layer OL1 can be disposed on a side of the first substrate SB1 facing or facing away from the light source 110, and the second optical layer OL2 can be disposed on a side of the second substrate SB2 facing or facing away from the light source 110.

[0060] As Figure 4 and Figure 5 shown, the light source 110 of one of the two optical modules 100 can emit light rays La, and the light rays La travel to the first surface S1 and are deflected by the first optical layer OL1 of the first surface S1 into deflected light L0a. The deflected light L0a passes through the second optical layer OL2 of the second surface S2 to generate a predetermined pattern PA. On the other hand, the light source 110 of the other of the two optical modules 100 can emit light rays Lb, and the light rays Lb travel to the first surface S1 and are deflected by the first optical layer OL1 of the first surface S1 into deflected light L0b. The deflected light L0b passes through the second optical layer OL2 of the second surface S2 to generate another predetermined pattern PA. The combination of the above two predetermined patterns PA forms a design pattern DPA. Accordingly, the projection device PRO including two optical modules 100 can project the design pattern DPA.

[0061] The traveling direction of the deflected light L0a is different from the traveling direction of the deflected light L0b. For example, as Figure 5As shown, the traveling direction of the deflected light L0a has an included angle θa with respect to the direction Z in the clockwise direction, while the traveling direction of the deflected light L0b has an included angle θb with respect to the direction Z in the counterclockwise direction, where the included angle θa may be the same as or different from the included angle θb. The different traveling directions of the deflected light L0a and the deflected light L0b may be formed, for example, by the different tilting directions of the two first surfaces S1, but not limited thereto. For example, as Figure 4 shown, the tilting direction of the first surface S1 in the optical module 100 on the right side is different from the tilting direction of the first surface S1 in the optical module 100 on the left side.

[0062] Through the structural design of the above projection device PRO, the projection device PRO can have a large-size projection field of view, and can combine two or more small-size predetermined patterns PA projected by different optical modules simultaneously to form and project a large-size design pattern DPA. In some embodiments, multiple predetermined patterns PA can be generated by a time-division multiplexing method instead of simultaneously, but not limited thereto.

[0063] In summary, according to the optical module and the projection device to which it is applied according to the embodiments of the present invention, through the structural design of the optical module including a first surface configured to deflect light and a second surface configured to project a predetermined pattern, the optical module can have a large projection field of view and can reduce the human eye safety problem. In addition, through the different traveling directions of the deflected light, two or more small-size patterns can be combined to form and project a large pattern. Briefly, the optical module includes two optical layers to form two different surfaces with different functions. One of the two surfaces' optical layers provides a deflection function, and the other of the two surfaces' optical layers provides a function of generating a predetermined projection pattern. According to the above structural design, a small-size optical module capable of projecting a large field of view pattern is provided. Furthermore, two different optical layers with simple functions only require a simple manufacturing process, thereby reducing the manufacturing cost.

[0064] The above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims

1. An optical module, comprising: a light source for emitting light; as well as An optical structure, disposed on the light source and used to receive the light, the optical structure comprising: a first surface configured to deflect the light; as well as A second surface is configured to project a predetermined pattern when the light passes through the second surface, and the second surface has a plurality of microstructures, wherein the second surface corresponds to the first surface. 2 . The optical module as claimed in claim 1 , wherein the first surface is disposed between the second surface and the light source, and the light passes through the second surface after being deflected by the first surface. 3 . The optical module as claimed in claim 1 , wherein the second surface is disposed between the first surface and the light source, and the light is deflected by the first surface after passing through the second surface. 4 . The optical module as claimed in claim 1 , wherein the optical structure comprises a substrate, and the first surface and the second surface are located on opposite sides of the substrate. 5 . The optical module as claimed in claim 4 , wherein the first surface faces the light source, and the second surface faces away from the light source. 6 . The optical module as claimed in claim 1 , wherein the optical structure comprises a first substrate and a second substrate, the second substrate corresponds to the first substrate, wherein the first surface is located on one side of the first substrate, and the second surface is located on one side of the second substrate. 7 . The optical module as claimed in claim 6 , wherein the first surface faces the light source, and the second surface faces the light source. 8 . The optical module as claimed in claim 6 , wherein the first surface faces away from the light source, the second surface faces the light source, and both the first surface and the second surface are located between the first substrate and the second substrate. 9 . The optical module as claimed in claim 1 , wherein the light source comprises one of a laser diode, a vertical cavity surface emitting laser, a light emitting diode and a photonic crystal surface emitting laser. 10 . The optical module as claimed in claim 1 , wherein the first surface comprises a slope, a blazed grating, a prism or a prism array. 11 . The optical module as claimed in claim 1 , wherein the second surface comprises a microlens array, a diffractive optical element or a metasurface.

12. An optical module as described in claim 1, wherein the light is deflected by the first surface into a first deflected light and a second deflected light, the first deflected light passes through a first portion of the second surface to form a first sub-pattern, and the second deflected light passes through a second portion of the second surface to form a second sub-pattern, wherein the first sub-pattern and the second sub-pattern are combined to form the predetermined pattern.

13. The optical module of claim 12, wherein the first portion is different from the second portion. 14 . The optical module as claimed in claim 1 , further comprising a shading element surrounding the light source and the optical structure, wherein the shading element has an opening, and the light deflected by the first surface can pass through the opening.

15. A projection device comprising: At least two optical modules according to claim 1, wherein the at least two optical modules are arranged adjacent to each other, and a plurality of the predetermined patterns projected by the at least two optical modules are combined to form a design pattern.

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