Optical tracking device
By using the light-shielding cover plate and optical path recombination structure in the optical tracking device, the problems of insufficient sensing stability and high cost in the optical tracking system are solved, and the optical tracking effect with high accuracy and low cost are achieved.
Patent Information
- Application Number
- CN202411286664.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-02-26
- Filing Date
- 2024-09-13
- Publication Date
- 2025-08-26
AI Technical Summary
In the existing optical tracking system, the sensing stability is insufficient and the cost is high. How to improve the sensing stability and reduce the cost is an urgent problem.
The light-shading cover plate and optical path recombination structure are adopted. The light-shading cover plate blocks stray light. The optical path recombination structure uses the microstructure to recombinate the light path to eliminate stray light interference and improve optical tracking accuracy.
Effectively reduce the misjudgment rate, improve the sensing stability and accuracy of the optical tracking device, and achieve low-cost manufacturing.
Smart Images
Figure CN120539736A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an optical device, and in particular to an optical tracking device. Background Art
[0002] With technological advancements, more and more electronic products require tracking systems to determine the distance, position, or direction between the electronic product and the surrounding environment or the user (such as electric vehicles, smart appliances, and wearable devices). Among tracking systems, optical tracking offers the advantage of a long sensing distance. However, improving sensing stability while simultaneously reducing costs remains a challenge for manufacturers. Summary of the Invention
[0003] The present invention provides an optical tracking device that effectively reduces the proportion of stray light in sensing light, makes the sensing light have good sharpness, reduces the probability of misjudgment of the tracking device, and further increases sensing stability.
[0004] An optical tracking device according to one embodiment of the present invention includes a circuit substrate, a sensing light source, a light shielding cover, and an optical path reorganization structure. The light shielding cover is disposed on the sensing light source, and the optical path reorganization structure overlaps the sensing light source. The optical path reorganization structure has a first surface facing the sensing light source and a second surface facing away from the sensing light source. The first surface has a first microstructure, and the second surface has a second microstructure. Sensing light emitted by the sensing light source sequentially passes through the first microstructure and the second microstructure.
[0005] Based on the above, the optical tracking device of the present invention utilizes a light-shielding cover to be set on the sensing light source, and overlaps the light path reorganization structure with the sensing light source. The light-shielding effect of the light-shielding cover can block the unexpected light-emitting area and absorb stray light, and the light path reorganization structure is installed on the light outlet of the sensing light. In addition, the microstructure on the surface of the light path reorganization structure can cause the sensing light to diffuse and reorganize when passing through the microstructure, which is equivalent to moving the position of the sensing light source to the position of the light path reorganization structure, effectively eliminating the path of stray light arbitrarily penetrating, reflecting and scattering in other components, eliminating the light spot image appearing in the wrong position, avoiding interference and misjudgment of the tracking device, improving the accuracy of the optical tracking effect and avoiding misjudgment.
[0006] In order to make the above contents of the present invention more clearly understood, embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present invention and together with the description serve to explain the principles of the present invention.
[0008] Figure 1 is a schematic diagram of the optical structure of an optical tracking device according to one embodiment of the present invention;
[0009] Figure 2A and Figure 2B They are Figure 1 An exploded view and detailed structural diagram of an optical tracking device according to an embodiment;
[0010] Figure 3 is a schematic diagram of the optical structure of an optical tracking device according to one embodiment of the present invention;
[0011] Figure 4A and Figure 4B They are respectively a schematic diagram of the optical structure of an optical tracking device of a comparative embodiment and a schematic diagram of the generation of stray light. DETAILED DESCRIPTION
[0012] As used herein, "about," "approximately," "substantially," or "substantially" include the stated value and the mean value within an acceptable deviation range for the particular value as determined by one of ordinary skill in the art, taking into account the measurement in question and the particular amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within, for example, ±30%, ±20%, ±15%, ±10%, ±5%. Furthermore, as used herein, "about," "approximately," "substantially," or "substantially" can be selected based on the acceptable deviation range or standard deviation of the measured property, cut property, or other property, and may not apply to all properties without a single standard deviation.
[0013] In the accompanying drawings, the thickness of layers, films, panels, regions, etc. is exaggerated for clarity. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element, or an intermediate element can also exist. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there is no intermediate element. As used herein, "connection" can refer to physical and / or electrical connection. Furthermore, "electrical connection" can refer to the presence of other elements between two elements.
[0014] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.
[0015] Figure 1 It is a schematic diagram of the optical structure of an optical tracking device according to one embodiment of the present invention. Figure 2A and Figure 2B They are Figure 1The exploded view and detailed structure diagram of the optical tracking device of the embodiment. Please also refer to Figure 1 、 Figure 2A as well as Figure 2B The optical tracking device 10A includes a circuit substrate 100, a sensing light source 110, a light shielding cover 120, and an optical path reorganization structure 121 disposed on the light shielding cover 120. The sensing light source 110 is electrically connected to the circuit substrate 100 and is used to provide sensing light L. The optical tracking device 10A may further include an optical sensor (such as a camera) and a processor (neither of which are shown). When the light emitted by the sensing light L is reflected or refracted and finally reaches the optical sensor (such as a camera) of the optical tracking device 10A, the optical sensor converts the received sensing light L into an electrical signal. The processor can receive the electrical signal to determine information about the target object, such as the position change of the target object, the surface shape of the target object, or the movement path of the target object, but the present invention is not limited thereto.
[0016] The circuit substrate 100 may further include a substrate 111 and a circuit layer 112. The substrate 111 may be, for example, a printed circuit board (PCB) or a flexible printed circuit (FPC), and thus be flexible, but the present invention is not limited thereto. In other embodiments, the substrate 111 may be a solid glass substrate or a plastic substrate. The circuit layer 112 may include various signal lines, switching elements, drive circuits, and pads (none of which are shown) for providing and transmitting electrical signals to the sensing light source 110 to control the sensing light source 110 to emit sensing light L. The sensing light source 110 may be a light emitting diode (LED) or a laser diode (LD), and the wavelength range of the sensing light L emitted by the sensing light source 110 may be in the visible light band (e.g., a wavelength between 380 nm and 750 nm) or in the near-infrared to infrared light band (e.g., a wavelength above 750 nm or a wavelength above 1054 nm), but the present invention is not limited thereto.
[0017] The light shielding cover 120 is disposed on the sensing light source 110. The light shielding cover 120 may include, but is not limited to, a dark material (e.g., black), a material with a high optical density (e.g., an optical density OD value > 0.5), a material with a low transmittance (e.g., a transmittance < 30%) for the sensing light L, or a material with a high absorptivity for the sensing light L, and has both protective and aesthetic functions. The light path reorganization structure 121 is disposed overlapping the sensing light source 110. For example, Figure 2A and Figure 2BAs shown, the light path reorganization structure 121 may have an aperture AP that overlaps the sensing light source 110 when projected onto the circuit substrate 100. The light path reorganization structure 121 may be made of a plastic material with high transmittance and low absorption of the sensing light L, such as polyethylene terephthalate (PET), polymethylmethacrylate (PMMA), polystyrene (PS), or polycarbonate (PC), but the present invention is not limited thereto.
[0018] It is worth mentioning that the optical path reorganization structure 121 has a first surface S1 facing the sensing light source 110 and a second surface S2 facing away from the sensing light source 110, and the first surface S1 has a first microstructure M1, and the second surface S2 has a second microstructure M2, so that the sensing light L is emitted from the sensing light source 110 and passes through the first microstructure M1 and the second microstructure M2.
[0019] For example, the first microstructure M1 may be a concave-convex surface formed by sandblasting or surface atomization on the first surface S1 of the light path reorganization structure 121, or a plurality of prismatic structures. The second microstructure M2 may include, for example, a plurality of prismatic structures or a concave-convex surface formed by sandblasting or surface atomization. In embodiments where the second microstructure M2 includes a plurality of prismatic structures, the material of the second microstructure M2 may be the same as or different from the material of the light path reorganization structure 121, and may include, for example, UV glue or other suitable materials, but the present invention is not limited thereto.
[0020] When the sensing light source 110 emits sensing light L, the sensing light L may have a first field of view (FOV1). Due to the light-shielding effect of the light-shielding cover 120, a portion of the sensing light L is blocked from passing through the light-shielding cover 120. This prevents the sensing light L from being unexpectedly refracted, reflected, or diffused within the light-shielding cover 120, preventing the sensing light L from appearing in unexpected locations and reducing the chance of stray light generation. Furthermore, the majority of the sensing light L is transmitted out of the optical tracking device 10A from a position overlapping the optical path reorganization structure 121 of the sensing light source 110. This reduces the chance of misjudgment by the optical tracking device 10A and increases the accuracy of the optical tracking device 10A.
[0021] Moreover, when the sensing light L is transmitted to the first microstructure M1 of the first surface S1, the first microstructure M1 can reorganize the refraction path of the sensing light L, that is, the light-emitting direction of the sensing light L is randomly distributed and has a second field of view angle FOV2 that is larger than the first field of view angle FOV1. The effect is equivalent to a point light source being located at the position of the light path reorganization structure 121. From another perspective, the light path reorganization structure 121 is equivalent to moving the position of the sensing light source 110 to the position of the light path reorganization structure 121. On the other hand, through the refraction effect of the second microstructure M2, the sensing light L can be easily captured by the optical sensor when it is irradiated at a large angle, thereby increasing the tracking effect of the optical tracking device 10A. Both the light shielding cover 120 and the light path reorganization structure 121 can be manufactured using plastic injection molding, without high manufacturing costs, and can achieve low-cost mass production. Therefore, the optical tracking device 10A of the present invention has a simple structure, is easy to manufacture, is conducive to the miniaturization of the overall device, and has high optical tracking accuracy.
[0022] Please continue to refer to Figure 2A as well as Figure 2B The optical tracking device 10A may further include a spacer 140, which is disposed between the circuit substrate 100 and the light shielding cover 120. The spacer 140 may have an accommodation space AC, and the sensing light source 110 is disposed in the accommodation space AC. The spacer 140 is used to maintain an appropriate distance between the light shielding cover 120 and the circuit substrate 100 to prevent the light shielding cover 120 or the optical path reorganization structure 121 from colliding with the sensing light source 110 when the optical tracking device 10A is subjected to an external force collision. Based on the above, the height 140H of the spacer 140 on the circuit substrate 100 may be greater than the height 110H of the sensing light source 110 on the circuit substrate 100. The height 140H may be defined as the distance from the upper surface of the spacer 140 to the upper surface of the circuit substrate 100, and the height 110H may be defined as the distance from the light emitting surface 110S of the sensing light source 110 to the upper surface of the circuit substrate 100. In some embodiments, a suitable spacing d1 can be maintained between the spacer 140 and the sensing light source 110 (for example, in the plane of the circuit substrate 100, the ratio of the spacing d1 to the width of the sensing light source 110 is greater than 0.2), allowing for slight manufacturing process tolerances and providing a certain assembly margin. The spacer 140 can be made of, for example, plastic or metal, but the present invention is not limited thereto. In some embodiments, the spacer 140 can have an appropriate reflectivity so that the sensing light L, when it strikes the sidewalls of the spacer 140, is re-reflected toward the light path re-organizing structure 121, thereby increasing the light energy utilization efficiency of the sensing light L.
[0023] On the other hand, the optical tracking device 10A may further include a first adhesive layer 130A and a second adhesive layer 130B. The first adhesive layer 130A is disposed between the spacer 140 and the circuit substrate 100 to bond the spacer 140 and the circuit substrate 100 to each other. The second adhesive layer 130B is disposed between the spacer 140 and the light shielding cover 120 to bond the spacer 140 and the light shielding cover 120 to each other. On the other hand, on the projection surface of the circuit substrate 100, the first adhesive layer 130A, the second adhesive layer 130B and the spacer 140 all surround the sensing light source 110. It can also be understood that the first adhesive layer 130A, the second adhesive layer 130B and the spacer 140 together create an accommodating space AC for placing the sensing light source 110. The first adhesive layer 130A and the second adhesive layer 130B may be, for example, a pressure sensitive adhesive (PSA) having a certain absorptivity or reflectivity for the sensing light L, thereby reducing the proportion of sensing light L leaking from the first adhesive layer 130A and the second adhesive layer 130B, or increasing the light energy utilization rate of the sensing light L. The present invention is not limited to this. In other embodiments, the first adhesive layer 130A and the second adhesive layer 130B may also be other types of colloids or adhesive layers.
[0024] Another embodiment will be listed below to illustrate the present invention in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted. For the omitted parts, please refer to the above embodiment and will not be repeated below.
[0025] Figure 3 This is a schematic diagram of the optical structure of an optical tracking device according to one embodiment of the present invention. Figure 3 The optical tracking device 10B is similar to the optical tracking device 10A, with the difference that the optical tracking device 10B further includes an optical element 150, which is disposed between the optical path recombining structure 121 and the sensing light source 110. The optical element 150 is, for example, a plastic lens or a glass lens with positive refractive index, or other optical elements with a focusing function. When the sensing light L has a first field of view angle FOV1 after being emitted from the sensing light source 110, the optical element 150 can recycle and concentrate the sensing light L onto the optical path recombining structure 121, so as to facilitate the sensing light L to be guided out of the optical path recombining structure 121. In addition, the optical path recombining structure 121 can further recombine the sensing light L, so that the sensing light L can have a larger second field of view angle FOV2 when leaving the optical tracking device 10B. In this way, the optical element 150 can increase the light energy utilization rate of the sensing light L, and indirectly enhance the intensity of the sensing light L.
[0026] Figure 4A and Figure 4B They are respectively a schematic diagram of the optical structure of an optical tracking device of a comparative embodiment and a schematic diagram of the generation of stray light. Please also refer to Figure 4A as well as Figure 4B As a comparative example, the optical tracking device 1000 has, for example, a circuit substrate 100, a sensing light source 110, a spacer 140, and a transparent cover 200. When the display light L emitted by the sensing light source 110 is transmitted to the transparent cover 200, it is easy to cause the display light L to undergo unexpected refraction, reflection, and diffusion in the transparent cover 200, which can easily cause stray light SL to be generated at the edge of the transparent cover 200. Ultimately, the light spot image formed by the stray light SL will appear at an unexpected position, and there will be other uneven stray light spots, which will cause the tracking device to misjudge. Conversely, the optical tracking device 10A (or optical tracking device 10B) of the embodiment of the present invention can effectively solve the above problems and increase the accuracy of optical tracking.
[0027] In summary, the optical tracking device of the present invention utilizes a light-shielding cover plate to be set on the sensing light source, and overlaps the light path reorganization structure with the sensing light source. The light-shielding effect of the light-shielding cover plate can block the unexpected light-emitting area and absorb stray light, and the light path reorganization structure is installed at the light outlet of the sensing light. In addition, the microstructure on the surface of the light path reorganization structure can cause the sensing light to diffuse when passing through, which is equivalent to moving the position of the sensing light source to the position of the light path reorganization structure, effectively eliminating the path of stray light arbitrarily penetrating, reflecting and scattering in other components, eliminating the light spot image appearing in the wrong position, avoiding interference and misjudgment of the tracking device, and improving the accuracy of the optical tracking effect to avoid misjudgment.
[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. An optical tracking device, characterized in that: include: Circuit board; a sensing light source, electrically connected to the circuit substrate and configured to emit sensing light; as well as a light shielding cover, disposed on the sensing light source and comprising a light path reorganization structure overlapping the sensing light source, the light path reorganization structure having a first surface facing the sensing light source and a second surface facing away from the sensing light source; The first surface has a first microstructure, the second surface has a second microstructure, and the sensing light is emitted from the sensing light source and passes through the first microstructure and the second microstructure in sequence.
2. The optical tracking device according to claim 1, wherein: The first microstructure is a concave-convex surface or a plurality of prism structures.
3. The optical tracking device according to claim 1, wherein: The second microstructure includes a plurality of prism structures or is a concave-convex surface.
4. The optical tracking device according to claim 1, wherein: Also includes: A spacer is provided between the circuit substrate and the light shielding cover. The spacer has an accommodating space, and the sensing light source is provided in the accommodating space.
5. The optical tracking device according to claim 4, wherein: Also includes: a first adhesive layer disposed between the spacer and the circuit substrate; as well as The second adhesive layer is disposed between the spacer and the light shielding cover.
6. The optical tracking device according to claim 5, wherein: The height of the spacer on the circuit substrate is greater than the height of the sensing light source on the circuit substrate.
7. The optical tracking device according to claim 5, wherein: There is a distance between the spacer and the sensing light source.
8. The optical tracking device according to claim 5, wherein: On the projection surface of the circuit substrate, the first adhesive layer, the second adhesive layer, and the spacer all surround the sensing light source.
9. The optical tracking device according to claim 1, wherein: The light shielding cover has a transmittance of less than or equal to 30% for the sensing light.
10. The optical tracking device according to claim 1, wherein: It also includes an optical element, which is arranged between the light path reorganization structure and the sensing light source.