Optical distance measuring sensor configured to determine a proximity of a target object and electronic system

Abstract

The present disclosure relates to optical ranging sensors configured to determine proximity of a target object and electronic systems. The optical ranging sensor includes a housing cover including an emission opening and a reception opening, a light radiation source positioned to direct ranging light radiation through the emission opening toward the target object, a light radiation receiver positioned to receive ranging light radiation reflected from the target object through the reception opening, and a retroreflective mechanism implemented on a surface of the housing cover, wherein the retroreflective mechanism directs unwanted optical noise back toward a source of the unwanted optical noise and away from the light radiation receiver; wherein the proximity of the target object is determined based on one or more properties of the ranging light radiation.

Description

Technical Field

[0001] Embodiments of this disclosure generally relate to noise reduction mechanisms on optical sensors (e.g., optical range sensors, optical proximity sensors, and / or optical image sensors), and more particularly, to reducing optical noise from undesirable sources by utilizing retroreflective mechanisms on the surface of an optical sensor housing cover. Background Technology

[0002] Various example embodiments address technical problems associated with optical noise from undesirable sources in optical ranging, proximity, or image sensors. During operation of an optical ranging sensor, light can be received from various sources, including reflections from a target object, reflections from multiple surfaces of the optical ranging sensor and its external covering, and / or light from ambient sources. Light from undesirable sources, such as reflections from multiple surfaces of the optical ranging sensor and / or light from ambient sources, increases the noise received at the light radiation receiver and reduces the signal-to-noise ratio (SNR) of reflections from the target object. Increased noise can lead to inaccurate and / or inconsistent readings from the optical ranging sensor.

[0003] The applicant has identified numerous technical challenges and difficulties associated with reducing optical noise received at the light radiation receiver of optical ranging, proximity, or image sensors. Through effort, ingenuity, and innovation, the applicant has addressed the problems related to receiving optical noise in optical ranging sensors by developing solutions implemented in this disclosure, which will be described in detail below. Utility Model Content

[0004] Various embodiments relate to example optical ranging sensors and example electronic systems, the example electronic systems including an optical ranging sensor configured to reduce unwanted optical noise at a light radiation receiver. An example optical ranging sensor configured to determine the proximity of a target object may include a housing cover including a transmitting opening and a receiving opening. The example optical ranging sensor may further include a light radiation source positioned to direct ranging light radiation through the transmitting opening toward a target object, a light radiation receiver positioned to receive ranging light radiation reflected from the target object through the receiving opening, and an anti-reflection mechanism implemented on the surface of the housing cover. In some embodiments, the anti-reflection mechanism directs unwanted optical noise back toward the unwanted optical noise source and away from the light radiation receiver. The proximity of the target object may be determined based on one or more properties of the ranging light radiation received at the light radiation receiver.

[0005] In some embodiments, the housing cover also includes a top surface opposite to the light radiation receiver, wherein the retroreflective mechanism is deployed such that the top surface of the housing cover is substantially covered.

[0006] In some embodiments, the portion of the housing cover between the receiving opening and the transmitting opening includes the retroreflective mechanism.

[0007] In some embodiments, one or more opening surfaces defining the transmitting opening and the receiving opening include the retroreflective mechanism.

[0008] In some embodiments, one or more blocking surfaces positioned between the light radiation source and the light radiation receiver include the retroreflective mechanism.

[0009] In some embodiments, the optical ranging sensor may further include a receiving optical structure positioned between a light radiation receiver and a target object, wherein the receiving optical structure is configured to direct ranging light radiation toward the light radiation receiver.

[0010] In some embodiments, the optical ranging sensor may further include a transmitting optical structure positioned between the light radiation source and the target object, wherein the transmitting optical structure is configured to direct ranging light radiation toward the target object.

[0011] In some embodiments, the retroreflective mechanism includes a corner retroreflector.

[0012] In some embodiments, the retroreflective mechanism includes a cat's eye retroreflector.

[0013] In some embodiments, the retroreflective mechanism includes at least one of a retroreflective coating and a retroreflective strip.

[0014] In some embodiments, the one or more properties of the ranging optical radiation include at least one of the time of flight of the optical radiation and the intensity of the optical radiation.

[0015] In some embodiments, the proximity of the target object includes at least one of the following: the distance between the target object and the optical ranging sensor, the position of the target object relative to the optical ranging sensor, and the velocity of the target object.

[0016] Example electronic systems configured to determine the proximity of a target object are also provided. In some embodiments, the example electronic system may include an external cover and an optical ranging sensor deployed inside the external cover, opposite to the target object. The optical ranging sensor may include: a housing cover including a transmitting opening and a receiving opening; a light radiation source positioned to direct ranging light radiation through the transmitting opening toward the target object; a light radiation receiver positioned to receive ranging light radiation reflected from the target object through the receiving opening; and an anti-reflection mechanism deployed on the surface of the housing cover, wherein the anti-reflection mechanism directs unwanted optical noise back toward an optical noise source, away from the light radiation receiver. In some embodiments, the proximity of the target object is determined based on one or more properties of the ranging light radiation.

[0017] In some embodiments, the housing cover also includes a top surface opposite to the light radiation receiver, wherein the retroreflective mechanism is deployed such that the top surface of the housing cover is substantially covered.

[0018] In some embodiments, the portion of the housing cover located between the receiving opening and the transmitting opening includes the retroreflective mechanism.

[0019] In some embodiments, one or more opening surfaces defining the transmitting opening and the receiving opening include the retroreflective mechanism.

[0020] In some embodiments, one or more blocking surfaces positioned between the light radiation source and the light radiation receiver include the retroreflective mechanism.

[0021] In some embodiments, the retroreflective mechanism includes at least one of a corner retroreflector and a cat's eye retroreflector.

[0022] In some embodiments, the retroreflective mechanism includes at least one of a retroreflective coating and a retroreflective strip.

[0023] In some embodiments, the proximity of the target object includes at least one of the following: the distance between the target object and the optical ranging sensor, the position of the target object relative to the optical ranging sensor, and the velocity of the target object. Attached Figure Description

[0024] Reference will now be made to the accompanying drawings. Components shown in the figures may or may not be presented in some embodiments described herein. According to exemplary embodiments of this disclosure, some embodiments may include fewer (or more) components than those shown in the figures.

[0025] Figure 1 A cross-sectional view of an example optical ranging system according to an exemplary embodiment of the present disclosure is shown, which receives unwanted optical noise from multiple sources at the optical radiation receiver.

[0026] Figures 2A-2B A cross-sectional view of an example housing cover assembly including a retroreflective mechanism according to an example embodiment of the present disclosure is shown.

[0027] Figure 3 A cross-sectional view of an example housing cover according to an exemplary embodiment of the present disclosure is shown, the example housing cover including an retroreflective mechanism positioned on the top surface of the housing cover.

[0028] Figure 4 A cross-sectional view of an example housing cover according to an exemplary embodiment of the present disclosure is shown, the example housing cover including an retroreflective mechanism positioned on the top surface of the housing cover between a transmitting opening and a receiving opening.

[0029] Figure 5 A cross-sectional view of an example optical ranging system according to an exemplary embodiment of the present disclosure is shown. The example optical ranging system includes an retroreflective mechanism positioned to reflect unwanted optical noise away from the light radiation receiver.

[0030] Figures 6A-6B A cross-sectional view of an example retroreflective mechanism including a corner retroreflector and a cat's eye retroreflector according to an exemplary embodiment of the present disclosure is illustrated.

[0031] Figure 7 Several example electronic systems utilizing optical ranging sensors are illustrated according to exemplary embodiments of the present disclosure. Detailed Implementation

[0032] Example embodiments will be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, embodiments of the invention disclosed herein. In fact, embodiments of the invention may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to enable the disclosure to meet applicable legal requirements. The same reference numerals denote the same elements throughout the drawings.

[0033] Various example embodiments address technical problems associated with receiving optical noise from undesirable sources at the optical radiation receiver of an optical ranging, proximity, or image sensor. As those skilled in the art to which this disclosure pertains will understand, there are numerous example scenarios in which the accuracy and consistency of an optical ranging, proximity, or image sensor can be improved by reducing the amount of undesirable optical noise received at the optical radiation receiver.

[0034] During the operation of an optical ranging sensor, a light source emits ranging light radiation. This ranging light radiation can be directed through one or more emitting optical structures, a display screen, a cover glass, and / or lenses toward a target object. A portion of the ranging light radiation can be reflected by the target object and received by a light radiation receiver. The received ranging light radiation can be correlated with the emitted ranging light radiation to determine certain characteristics related to the proximity of the target object, such as the distance to the target object, the position of the target object, the motion of the target object, and / or the velocity of the target object.

[0035] In addition to the ranging light radiation reflected from the target object, light radiation may also be received from various undesirable sources. Light radiation received from undesirable sources (or undesirable optical noise) can weaken the reflected ranging light radiation. For example, light radiation from undesirable sources (such as, but not limited to, reflections from multiple surfaces and / or external coverings of the optical ranging sensor and / or any object not including the target, and / or light from ambient sources) increases the noise received at the light radiation receiver. This increase in undesirable optical noise corresponds to a decrease in the signal-to-noise ratio (SNR) of the ranging light radiation reflected from the target object. Due to the reduced SNR caused by undesirable optical noise, the proximity accuracy output from the optical ranging sensor becomes increasingly inaccurate and inconsistent.

[0036] In some examples, mitigating unwanted optical noise reception has included selecting housing materials and positioning reflective surfaces. For instance, an optical rangefinder manufacturer might choose materials that absorb one or more wavelengths of light. However, these materials often have limitations in terms of the necessary characteristics of the housing cover. Furthermore, an optical rangefinder manufacturer might choose materials and / or surfaces that randomly diffuse any incident light. This option could randomly reflect light towards the light radiation receiver, and so on.

[0037] The various example embodiments described herein utilize a variety of techniques to redirect unwanted optical noise away from the light radiation receiver of the optical rangefinder. For example, in some embodiments, one or more retroreflective mechanisms may be provided on multiple surfaces of the housing cover of the optical rangefinder to limit the amount of unwanted optical noise received at the optical sensor.

[0038] Generally, retroreflective mechanisms cause guided light radiation to return in the direction of the light radiation source. By guiding the light radiation towards the light radiation source, the light radiation is directed away from the light radiation receiver. Retroreflective mechanisms may include corner retroreflectors, cat's eye retroreflectors, retroreflective coatings, retroreflective strips, etc. In some embodiments, retroreflective mechanisms may be added to all surfaces of the housing cover, including the top surface of the housing cover, the inner surface of the housing cover, the opening surface of the housing cover, the blocking surface of the housing cover, etc. Such retroreflective mechanisms may be incorporated into the surface of the housing cover during the housing cover forming process.

[0039] Furthermore, in some embodiments, the retroreflective mechanism can be strategically positioned on a surface of the housing cover where most of the unwanted optical noise is reflected into the light radiation receiver. For example, in some embodiments, the entire top surface of the housing cover may include the retroreflective mechanism, while the inner surface, opening surface, and / or blocking surface may not include the retroreflective mechanism. In some example embodiments, only the top surface between the transmitting and receiving openings in the housing cover may include the retroreflective mechanism.

[0040] By using retroreflective mechanisms on one or more surfaces of the housing cover of an optical ranging, proximity, or imaging sensor, the amount of unwanted optical noise received at the light radiation receiver can be significantly reduced. Reducing unwanted optical noise at the light radiation receiver can improve the performance and overall consistency of optical ranging, proximity, or imaging devices. As illustrated by the examples described herein and the results of some examples, the effectiveness of optical ranging, proximity, or imaging sensors can be significantly improved.

[0041] Now for reference Figure 1 An example ranging system 100 is shown, which includes an optical ranging sensor 102 that operates without retroreflective features. Figure 1 As shown, the optical ranging system 100 includes an optical ranging sensor 102, which includes a light source 104 configured to direct ranging light radiation 118 through an emitting optical structure 114 (e.g., a lens) placed in an emitting opening 126 of a housing cover 108 and through an external cover 116 (e.g., a screen) toward a target object 110. The ranging light radiation 118 is reflected by the target object 110 and returns through a receiving opening 124 and a receiving optical structure 122 in the housing cover 108 for reception at a light radiation receiver 106. Figure 1 As further shown, the light source 104 and the light receiver 106 are electrically connected to the substrate 112 (e.g., a printed circuit board). Additionally, a housing cover 108 is attached to the substrate 112. Figure 1 As shown, unwanted light radiation from multiple sources (e.g., unwanted ambient optical noise 120a, unwanted crosstalk optical noise 120b-120e) is reflected from multiple surfaces of the housing cover 108 and received at the light radiation receiver 106.

[0042] like Figure 1The example optical ranging sensor 102 shown includes a light source 104. The light source 104 is any device, light bulb, semiconductor, diode, laser, or other photonic emitting structure configured to generate ranging light radiation 118 and positioned to direct the ranging light radiation 118 toward a target object 110. The light source 104 can include any light source, such as a laser diode, light-emitting diode, light bulb, semiconductor device, or other photonic emitting structure. In some embodiments, the light source 104 can include a semiconductor laser diode, such as a vertical-cavity surface-emitting laser (VCSEL) and / or an edge-emitting laser diode. Generally, the light source 104 can output a coherent beam of light when a current is received. In the optical ranging sensor 102, the proximity of a target object 110 in the environment can be measured by generating pulsed or continuous-wave ranging light radiation 118, receiving reflected pulsed or continuous-wave ranging light radiation 118, and determining the time of flight of the pulsed or continuous-wave ranging light radiation 118. The proximity of the target object 110 may include the distance between the target object 110 and the optical ranging sensor 102, the position of the target object 110, the speed of the target object 110, the direction of motion of the target object 110, and other similar characteristics related to the position of the target object 110 in the environment.

[0043] like Figure 1 As further illustrated, the example optical ranging sensor 102 includes a light radiation receiver 106. The light radiation receiver 106 can be any collection of one or more photodiodes, integrated circuits, devices, sensors, photosensitive diodes, or other structures that generate an electrical signal due to light received at the light radiation receiver 106. For example, the electrical signal output by the light radiation receiver 106 can increase with the number of photons striking the light radiation receiver 106 per second. In such an embodiment, the current output from the light radiation receiver 106 can be used to determine the intensity or amplitude of the ranging light radiation 118 striking the light radiation receiver 106. In some embodiments, the light radiation receiver 106 can be a photosensitive semiconductor diode that generates electron-hole pairs at a pn junction when photons with sufficient energy strike the light radiation receiver 106.

[0044] like Figure 1 As shown, the light radiation receiver 106 is electrically connected to the substrate 112. In some embodiments, the light radiation receiver 106 may also be electrically connected to a processing device. The processing device may be configured to receive an electrical signal generated by the light radiation receiver 106, which represents the intensity or other properties of the light radiation received at the light radiation receiver 106. In some embodiments, the processing device may determine the time of flight of the ranging light radiation 118 based on the electrical signal received by the light radiation receiver 106, and determine one or more characteristics related to the physical location of the target object 110.

[0045] like Figure 1 As further shown, the optical range sensor 102 includes a substrate 112. The substrate 112 is any structure configured to support attachment of the optical range sensor 102, including a housing cover 108. In some embodiments, the substrate 112 may include a printed circuit board (PCB) or alumina ceramic, which includes electrical connections to connect the optical range sensor 102 to a processor, controller, analog-to-digital converter, or other electrical components.

[0046] like Figure 1 As further shown, the example optical rangefinder 102 includes a housing cover 108. The housing cover 108 can be any package, cover, container, or other covering configured to protect the internal electrical components and circuitry of the optical rangefinder 102. The housing cover 108 can include plastic, ceramic, or other protective materials. The housing cover 108 is attached to the substrate 112 to provide stability and further protect the internal electrical components of the optical rangefinder 102. In some embodiments, the housing cover 108 may also include conductive pins and / or conductive pads to provide electrical connections to the internal electrical components.

[0047] like Figure 1 As further shown, the housing cover 108 includes an emission opening 126 and a receiving opening 124. The openings in the housing cover 108 allow for the emission and reception of light radiation entering and exiting the optical rangefinder 102. For example, the emission opening 126 can be aligned with the emission cone of the light source 104. Rangefinder light radiation 118 from the light source 104 can pass through the emission opening 126 toward the target object 110. Similarly, the receiving opening 124 allows for the reception of reflected rangefinder light radiation 118 entering the optical rangefinder 102, for example, to be received by the light radiation receiver 106 and analyzed by a processor or other device.

[0048] like Figure 1As further shown, the light source 104 is configured to output ranging light radiation 118. The ranging light radiation 118 can be any light signal emitted by the optical ranging sensor 102 towards the target object 110, used to determine characteristics related to the proximity of the target object 110. In some embodiments, the ranging light radiation 118 can be a pulsed laser signal. For example, the light source 104 can be configured to generate uniform laser pulses. Using a pulsed laser signal allows the controller to determine the time of flight of the ranging light radiation 118 once it is received at the light radiation receiver 106. In some embodiments, the ranging light radiation 118 can be a continuous-wave laser signal. In such embodiments, a continuous-wave laser signal allows the controller to determine the proximity of the target object 110 by correlating the proximity of the target object 110 with the phase change in the ranging light radiation 118 as it is emitted by the light source 104, reflected from the target object 110, and subsequently received by the light radiation receiver 106.

[0049] like Figure 1 As further shown, the ranging light radiation 118 is configured to pass through the emission opening 126. (As illustrated...) Figure 1 As shown, in some embodiments, the emission opening 126 includes an emission optics structure 114. The emission optics structure 114 is any transparent and / or translucent device configured to allow the ranging light radiation 118 to pass through. In some embodiments, the emission optics structure 114 may include an optical lens, an assembly of optical lenses, or other optical devices configured to distort the ranging light radiation 118. For example, the emission optics structure 114 may direct, converge, or guide the ranging light radiation 118 toward a target object 110 or a dynamic portion of the target object 110. In some embodiments, the emission optics structure 114 may be a transparent device positioned to prevent dust, dirt, and other impurities from entering the internal cavity of the optical ranging sensor 102. In some embodiments, the emission optics structure 114 may be a bandpass filter to limit the ranging light radiation 118 emitted by the light radiation source 104 to a narrow wavelength range. In some embodiments, the emission optics structure 114 may be positioned on the outer surface of the housing cover 108.

[0050] like Figure 1 As further shown, the reflected ranging light radiation 118 is configured to be reflected from the target object 110 and pass through the receiving opening 124. (As illustrated...) Figure 1As shown, in some embodiments, the receiving opening 124 includes a receiving optical structure 122. The receiving optical structure 122 is any transparent and / or semi-transparent device configured to allow reflected ranging light radiation 118 to pass through. In some embodiments, the receiving optical structure 122 may include an optical lens, an optical lens assembly, or other optical devices configured to distort the ranging light radiation 118 such that the ranging light radiation 118 is focused onto the light radiation receiver 106. In some embodiments, the receiving optical structure 122 may be a transparent device positioned to prevent dust, dirt, and other impurities from entering the internal cavity of the optical ranging sensor 102. In some embodiments, the receiving optical structure 122 may be a bandpass filter to prevent noise of unwanted wavelengths from reaching the light radiation receiver 106. In some embodiments, the receiving optical structure 122 may be positioned on the outer surface of the housing cover 108.

[0051] like Figure 1 As further shown, the optical ranging system 100 may include an external cover 116, such as an electronic display screen. The external cover 116 is any transparent and / or semi-transparent device positioned outside the optical ranging sensor 102 through which the ranging light radiation 118 passes to encounter the target object 110.

[0052] In some embodiments, the external cover 116 may be an electronic display screen of an electronic device, such as a mobile phone. In such embodiments, an optical ranging sensor 102 emits and receives ranging light radiation 118 through the electronic display screen to determine the proximity characteristics of a target object 110 outside the mobile device. The electronic display screen may be any digital display, screen, monitor, or other device configured to output information in a visual form based on received electronic signals. The electronic display screen may be transparent or translucent for certain wavelengths of light, such that the reflected ranging light radiation 118 can be received by a light radiation receiver 106 behind or below the electronic display screen.

[0053] In some embodiments, the outer cover 116 may be a protective cover that separates the sensor from external components. In such an embodiment, the optical ranging sensor 102 emits and receives ranging light radiation 118 through the outer cover 116 to determine the proximity characteristics of a target object 110 outside the mobile device. The outer cover 116 may be any barrier that protects the sensor and other components from any foreign matter, such as, but not limited to, dust, water, and oil. The outer cover 116 may be transparent or translucent to certain wavelengths of light, such that reflected ranging light radiation 118 can be received by a light radiation receiver 106 behind or beneath the outer cover 116.

[0054] like Figure 1As further shown, the ranging light radiation 118 emitted by the optical ranging sensor 102 is reflected from the target object 110 and returned to the light radiation receiver 106 of the optical ranging sensor 102. The target object 110 can be any object, structure, person, entity, or other object located within the line of sight of the ranging light radiation 118 emitted by the optical ranging sensor 102. In some embodiments, the optical ranging sensor 102 can be configured to determine one or more proximity characteristics of the target object 110, such as the spatial position, movement, and / or velocity of the target object 110. For example, in some embodiments, the optical ranging sensor 102 can be positioned below the electronic display screen of a mobile device and can be configured to detect the target object 110 closer than a predetermined threshold of the optical ranging sensor 102. In instances where the target object 110 is closer than the predetermined threshold of the optical ranging sensor 102, the mobile device can deactivate the touchscreen, turn off the display, or take any other related action.

[0055] like Figure 1 As further illustrated, unwanted optical noise 120a-120e may be received at the optical radiation receiver 106 of the optical ranging sensor 102. Undesirable optical noise 120a-120e refers to any optical radiation received at the optical radiation receiver 106 that is not emitted by the optical radiation source 104 or does not follow a direct path from the optical radiation source 104 to the target object 110 and back to the optical radiation receiver 106. For example, as... Figure 1 The unwanted optical noise 120a shown originates from unwanted optical noise sources, such as ambient light sources outside the optical ranging sensor 102. Ambient light sources can be external light, sunlight, another light source, another source emitting laser and / or pulsed or continuous wave laser, and similar external light sources.

[0056] like Figure 1 As further illustrated, undesirable optical noise 120e may be emitted directly from the light source 104 to the light receiver through the internal compartment of the optical rangefinder sensor. Undesirable optical noise 120e may be due to gaps in the obstruction separating the light source 104 and the light receiver 106, and / or due to insufficient obstruction separating the light source 104 and the light receiver 106. Figure 1 As further illustrated, the undesirable optical noise 120b-d may be due to emitted ranging light radiation 118 reflected from multiple surfaces of the optical ranging sensor 102 and / or the external cover 116.

[0057] Undesired optical noise 120a-120e received from unwanted light sources or from various reflections of ranging light radiation 118 unrelated to the target object may reduce the ability of the optical ranging sensor 102 to detect ranging light radiation 118 reflected from the target object 110. An increase in undesired optical noise 120a-120e may lead to a decrease in the signal-to-noise ratio (SNR) of the ranging light radiation 118 reflected from the target object 110. As the SNR decreases due to undesired optical noise 120a-120e, the determined proximity characteristics of the target object 110 may become increasingly inaccurate and inconsistent.

[0058] Although Figure 1 The optical range sensor 102 is shown as an optical ranging device, but it can be any optical sensor configured to emit light radiation and receive unwanted light radiation at a receiver. For example, the optical range sensor 102 may include an optical proximity sensor. In another embodiment, the optical range sensor 102 may include an imaging device configured to receive reflected light radiation.

[0059] Now for reference Figures 2A-2B An example assembly of a housing cover 208 including a retroreflective mechanism 230 is shown. Figure 2A As shown, before the housing cover 208 is attached to the substrate 212, the retroreflective mechanism 230 is positioned on all surfaces of the housing cover 208. The surfaces of the housing cover 208 on which the retroreflective mechanism 230 is deployed include a top surface 236, an opening surface 232, a blocking surface 234, an inner surface 238, and an outer surface 240.

[0060] like Figure 2A As shown, the housing cover 208 includes a retroreflective mechanism 230. The retroreflective mechanism 230 is any structure, material, object, frame, or other optical device that reflects guided light radiation back to the light radiation source with minimal scattering. The retroreflective mechanism 230 may include optical elements and / or reflective surfaces to reflect incident light back at an angle close to the angle of incidence. In some embodiments, the retroreflective mechanism 230 may include a combination of... Figure 6A Further description of corner retroreflectors and / or combinations Figure 6BThe cat's eye retroreflector is further described. Other retroreflective mechanisms 230 may include retroreflective coatings and / or retroreflective strips. The retroreflective mechanism 230 may be applied to the surface of the housing cover 208 as part of the manufacturing process, after the housing cover 208 is manufactured but before it is attached to the substrate 212, and / or after it is attached to the substrate 212. By applying the retroreflective mechanism 230 to the surface of the housing cover 208, any undesired optical noise encountering the retroreflective mechanism 230 on the surface of the housing cover 208 will be reflected back toward the source of the undesired optical noise, such as light radiation source 204, ambient noise source, or another source of undesired optical noise.

[0061] like Figure 2A As shown, the housing cover 208 includes a plurality of inner surfaces 238, outer surfaces 240, and opening surfaces 232. The inner surfaces 238 are any surfaces within the internal cavity formed by the housing cover 208 and adjacent to internal components (e.g., light source 204, light receiver 206) of the optical ranging sensor 202. The inner surfaces 238 include blocking surfaces 234. Blocking surfaces 234 are any surfaces of the housing cover 208 on the internal blocking members that separate the light source 204 from the light receiver 206. In some embodiments, one or more inner surfaces 238 may include retroreflective mechanisms 230. For example, the blocking surface 234 adjacent to the light source 204 may include retroreflective mechanisms 230 for preventing unwanted optical noise (such as...). Figure 1 The unwanted crosstalk optical noise 120e shown is emitted directly from the light source 204 to the light receiver 206 through the internal cavity of the optical ranging sensor 202.

[0062] The outer surface 240 of the housing cover 208 is any surface outside the internal cavity defined by the housing cover 208. The outer surface 240 includes a top surface 236. The top surface 236 is the surface outside the internal cavity defined by the housing cover 208, including an emission opening 226 and a receiving opening 224, for ranging light radiation (e.g., as per...). Figure 1 The rangefinding light radiation 118 described herein is emitted and received. In some embodiments, one or more of the outer surfaces 240 may include retroreflective mechanisms 230. For example, the top surface 236 may include retroreflective mechanisms 230, which prevent unwanted optical noise (such as...) Figure 1 The unwanted crosstalk optical noise 120b-120e shown is emitted directly from the light source 204 to the light receiver 206 by reflection from the top surface 236.

[0063] The opening surface 232 includes any surface of the housing cover 208 that defines openings (e.g., receiving opening 224 and transmitting opening 226) in the housing cover 208 leading to the internal cavity. In some embodiments, one or more of the opening surfaces 232 may include a retroreflective mechanism 230. For example, the opening surface 232 defining the receiving opening 224 may include a retroreflective mechanism 230 that prevents unwanted optical noise (such as...) Figure 1 The unwanted ambient optical noise 120a) shown is reflected from the opening surface 232 and emitted to the light radiation receiver 206.

[0064] like Figure 2B As further shown, a housing cover 208, including a retroreflective mechanism 230, is attached to a substrate 212, thereby forming a protective barrier around the light radiation source 204, the light radiation receiver 206, and other internal components of the optical range sensor 202. Furthermore, a transmitting optical structure 214 and a receiving optical structure 222 are attached to the housing cover 208 at a transmitting opening 226 and a receiving opening 224, respectively, to further protect the internal components of the optical range sensor 202.

[0065] Now for reference Figure 3 An example embodiment of an optical ranging sensor 302 including a retroreflective mechanism 330 is provided. For example... Figure 3 As shown, the example optical rangefinder 302 includes a housing cover 308 attached to a substrate 312, the housing cover 308 defining an internal cavity that includes internal electrical components of the optical rangefinder 302, such as a light source 304 and a light receiver 306. Figure 3 As further shown, the housing cover 308 includes an emission opening 326 through which the light radiation source 304 can emit ranging light radiation (e.g., as shown in the diagram). Figure 1 The ranging light radiation 118 shown is illustrated. Furthermore, the housing cover 308 includes a receiving opening 324 through which reflected ranging light radiation can be received at the light radiation receiver 306. The example optical ranging sensor 302 also includes an retroreflective mechanism 330 deployed across the top surface 336 of the housing cover 308.

[0066] In some embodiments, due to manufacturing difficulty, total cost, or other limiting factors, the retroreflective mechanism 330 may be positioned only on a selected portion of the housing cover 308. For example... Figure 3 As shown, the example retroreflective mechanism 330 is positioned to substantially cover the top surface 336 of the housing cover 308. Figure 1As shown, the top surface 336 of the housing cover 308 can be a significant source of unwanted optical noise due to crosstalk reflections. An anti-reflective mechanism 330 placed on the top surface 336 of the housing cover 308 redirects the unwanted optical noise to a light source, such as light source 304.

[0067] Now for reference Figure 4 An example embodiment of an optical ranging sensor 402 including a retroreflective mechanism 430 is provided. For example... Figure 4 As shown, the example optical rangefinder 402 includes a housing cover 408 attached to a substrate 412, defining an internal cavity that includes internal electrical components of the optical rangefinder 402, such as a light source 404 and a light receiver 406. Figure 4 As further shown, the housing cover 408 includes an emission opening 426 through which the light radiation source 404 can emit ranging light radiation (e.g., as shown in the diagram). Figure 1 The ranging light radiation 118 shown is illustrated. Furthermore, the housing cover 408 includes a receiving opening 424 through which reflected ranging light radiation can be received at the light radiation receiver 406. The example optical ranging sensor 402 also includes an retroreflective mechanism 430 deployed on the top surface 436 of the housing cover 408 between the transmitting opening 426 and the receiving opening 424.

[0068] As described herein, in some embodiments, due to manufacturing difficulty, total cost, or other limiting factors, the retroreflective mechanism 330 may be positioned on a limited portion of the housing cover 408. Figure 4 As shown, the example retroreflective mechanism 430 is positioned on the top surface 436 of the housing cover 308 between the transmitting opening 426 and the receiving opening 424. Figure 1 As shown, the top surface 436 of the housing cover 408, located between the emitting opening 426 and the receiving opening 424, can be a significant source of unwanted optical noise. For example, light radiation emitted from the light source 404 may be reflected from multiple surfaces of the housing cover, electronic screen, or other external coverings, the top surface of the housing cover, and other surfaces. In instances where unwanted optical noise due to such crosstalk reflections reaches the light receiver 406, invalid or inaccurate proximity results may be determined. An antireflective mechanism 430 placed on the top surface 436 of the housing cover 408, located between the emitting opening 426 and the receiving opening 424, redirects the unwanted optical noise back to the light source, such as the light source 404.

[0069] Now for reference Figure 5 An example optical ranging system 500 is provided, including an optical ranging sensor 502, which includes a retroreflective mechanism 530. For example... Figure 5 As shown, the optical ranging system 500 includes an optical ranging sensor 502, which includes a light source 504 configured to direct ranging light radiation 518 through an emission opening 526 in a housing cover 508, through an external cover 516 (e.g., a screen), and toward a target object 510. The ranging light radiation 518 is reflected by the target object 510 and returns through a receiving opening 524 in the housing cover 508 to be received at a light radiation receiver 506. Figure 5 As further shown, the light source 504 and the light receiver 506 are protected by a housing cover 508, which is attached to the substrate 512 and defines an internal cavity in which the internal electrical components of the optical ranging sensor 502 are deployed. Figure 5 As shown, the surface of the housing cover 508 includes a retroreflective mechanism 530, which is positioned to redirect light radiation from a variety of undesirable noise sources (e.g., undesirable ambient optical noise 520a, undesirable crosstalk optical noise 520b-520e) in a direction at or near the incident angle of the directed light radiation.

[0070] like Figure 5 As shown, unwanted noise may enter the optical ranging system 500 from various light radiation sources. For example, unwanted noise (e.g., unwanted ambient optical noise 520a) may enter the optical ranging system 500 from external sources. Furthermore, light radiation emitted from the light radiation source 504 may be reflected towards the light radiation receiver 506 from multiple surfaces of the housing cover, electronic screen, or other external covering 516, or other structures on or near the optical ranging sensor 502. Figure 5 As shown, the surface of the housing cover 508 includes a retroreflective mechanism 530. The retroreflective mechanism 530 redirects incident light in the direction in which the incident light encounters the retroreflective mechanism 530 on the surface of the housing cover 508. This prevents unwanted optical noise 520a-520e from being reflected toward the light radiation receiver 506.

[0071] Now for reference Figure 6A Example retroreflective mechanisms are provided (e.g., retroreflective mechanisms 230, 330, 430, 530). For example... Figure 6A As shown, the corner retroreflector surface 660 can be positioned on one or more surfaces of the housing cover (e.g., housing cover 108, 208, 308, 408, 508) as a retroreflective mechanism. As shown, the corner retroreflector 666 includes an array of three mutually perpendicular reflective surfaces 678 positioned to form the interior corners of a cube. Incident light 662a, 664a encountering the corner retroreflector 666 is guided back to the source of the incident light 662a, 664a as retroreflected light 662b, 664b.

[0072] like Figure 6A As further shown, a plurality of corner retroreflectors 666 may be positioned in a corner retroreflector surface 660. The corner retroreflector surface 660 may be manufactured on one or more surfaces of the housing cover as part of the housing cover manufacturing process. In some embodiments, the corner retroreflectors 666 and / or the corner retroreflector surface 660 may be deployed on one or more surfaces of the housing cover after the housing cover has been manufactured.

[0073] Now for reference Figure 6B Example retroreflective mechanisms are provided (e.g., retroreflective mechanisms 230, 330, 430, 530). For example... Figure 6B As shown, the cat's eye retroreflector 674 can be positioned on one or more surfaces of the housing cover (e.g., housing cover 108, 208, 308, 408, 508) as a retroreflective mechanism. Figure 6B As shown, the cat's eye retroreflector 674 typically includes a transparent sphere 672 and a spherical mirror 676. Incident light 668a, 670a entering the cat's eye retroreflector 674 is guided back to the source of the incident light 668a, 670a as retroreflected light 668b, 670b.

[0074] In some embodiments, a plurality of cat-eye retroreflectors 674 may be positioned across the surface of the housing cover. The cat-eye retroreflectors 674 may be manufactured on one or more surfaces of the housing cover as part of the housing cover manufacturing process. In some embodiments, the cat-eye retroreflectors 674 may be deployed on one or more surfaces of the housing cover after the housing cover has been manufactured.

[0075] Now for reference Figure 7 Several example electronic systems are provided, which are configured to use an optical range sensor 702 to determine the proximity of a target object. For example... Figure 7 As shown, the housing cover 708 includes a retroreflective mechanism 730 located on its surface. The housing cover 708 is attached to a substrate 712 to form a protective barrier defining an internal cavity in which the internal electrical components of the optical rangefinder 702 are disposed. As described herein, the retroreflective mechanism 730, disposed on one or more surfaces of the housing cover 708, can redirect unwanted optical noise (e.g., unwanted optical noise 120a-120e, 520a-520e) toward a source of unwanted optical noise. By redirecting the unwanted optical noise in the direction of the source, the unwanted optical noise is redirected away from the light radiation receiver of the optical rangefinder 702.

[0076] like Figure 7As further illustrated herein, various electronic systems (including but not limited to mobile phones 780, wearable devices 782, consumer electronics 784, and industrial electronics 786) can benefit from utilizing the optical ranging sensor 702 according to embodiments described herein. The SNR of the ranging light radiation reflected from the target object increases by reducing unwanted optical noise received at the light radiation receiver of the optical ranging sensor 702. The increased SNR improves the accuracy and consistency of the optical ranging sensor 702.

[0077] While this detailed description has illustrated some embodiments of the invention, the appended claims cover other embodiments of the invention that differ from the described embodiments due to various modifications and improvements. For example, those skilled in the art will recognize that these principles can be applied to any electronic device that uses a light source to determine the proximity and / or range of a target object. Examples include mobile devices such as telephones, tablets, and laptops; wearable electronic devices such as watches and earphones; consumer electronics such as robotic vacuum cleaners and projection systems; industrial electronics such as unmanned aerial vehicles, robots; and so on.

[0078] In the appended claims, unless the specific terms “means for” or “step for” are used in a given claim, the claim is not intended to be interpreted in accordance with paragraph 6 of 35 U.SC112.

[0079] The use of broader terms such as “comprising,” “including,” and “having” should be understood to support narrower terms such as “consisting of,” “substantially consisting of,” and “truly consisting of.” The use of terms such as “optionally,” “may,” “perhaps,” and “possibly” with respect to any element of the embodiments means that the element is not required, or alternatively, the element is required, both of which are within the scope of the embodiments(s). Furthermore, references to examples are provided for illustrative purposes only and are not intended to be exclusive.

Claims

1. An optical ranging sensor configured to determine the proximity of a target object, characterized in that, include: The outer casing includes: Launch opening; and Receiving opening; The light radiation source is positioned to guide the ranging light radiation through the emission opening toward the target object; A light radiation receiver is positioned to receive range-measuring light radiation reflected from a target object through a receiving opening; and The retroreflective mechanism is implemented on the surface of the outer casing. The retroreflective mechanism directs unwanted optical noise back toward the unwanted optical noise source and away from the light radiation receiver. The proximity of a target object is determined based on one or more properties of the ranging light radiation.

2. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, The housing cover also includes a top surface opposite to the light radiation receiver, wherein an anti-reflective mechanism is deployed such that the top surface of the housing cover is covered.

3. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, The portion of the outer casing located between the receiving opening and the transmitting opening includes the retroreflective mechanism.

4. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, One or more opening surfaces defining the transmitting opening and the receiving opening include the retroreflective mechanism.

5. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, One or more blocking surfaces positioned between the light radiation source and the light radiation receiver include the retroreflective mechanism.

6. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, Also includes: A receiving optical structure positioned between a light radiation receiver and a target object. The receiving optical structure is configured to guide the ranging light radiation toward the light radiation receiver.

7. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, Also includes: An optical emission structure positioned between a light radiation source and a target object. The emitting optical structure is configured to guide the ranging light radiation toward the target object.

8. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, The retroreflective mechanism includes a corner retroreflector.

9. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, The retroreflective mechanism includes a cat's eye retroreflector.

10. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, The retroreflective mechanism includes at least one of retroreflective coating and retroreflective strip.

11. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, The one or more properties of the ranging optical radiation include at least one of the time of flight of the optical radiation and the intensity of the optical radiation.

12. The optical ranging sensor configured to determine the proximity of a target object as described in claim 1, characterized in that, The proximity of the target object includes at least one of the following: the distance between the target object and the optical ranging sensor, the position of the target object relative to the optical ranging sensor, and the speed of the target object.

13. An electronic system configured to determine the proximity of a target object, characterized in that, include: External coverings; as well as An optical ranging sensor, deployed inside the external covering and opposite to the target object, comprises: The outer casing includes: Launch opening; and Receiving opening; The light radiation source is positioned to guide the ranging light radiation through the emission opening toward the target object; A light radiation receiver is positioned to receive range-measuring light radiation reflected from a target object through a receiving opening; and The retroreflective mechanism is deployed on the surface of the outer casing. The retroreflective mechanism guides unwanted optical noise away from the light radiation receiver and back toward the unwanted optical noise source. The proximity of a target object is determined based on one or more properties of the ranging light radiation.

14. The electronic system configured to determine the proximity of a target object as described in claim 13, characterized in that, The housing cover also includes a top surface opposite to the light radiation receiver, wherein an anti-reflective mechanism is deployed such that the top surface of the housing cover is covered.

15. The electronic system configured to determine the proximity of a target object as described in claim 13, characterized in that, The portion of the outer casing located between the receiving opening and the transmitting opening includes the retroreflective mechanism.

16. The electronic system configured to determine the proximity of a target object as described in claim 13, characterized in that, One or more opening surfaces defining the transmitting opening and the receiving opening include the retroreflective mechanism.

17. The electronic system configured to determine the proximity of a target object as described in claim 13, characterized in that, One or more blocking surfaces positioned between the light radiation source and the light radiation receiver include the retroreflective mechanism.

18. The electronic system configured to determine the proximity of a target object as described in claim 13, characterized in that, The retroreflective mechanism includes at least one of a corner retroreflector and a cat's eye retroreflector.

19. The electronic system configured to determine the proximity of a target object as described in claim 13, characterized in that, The retroreflective mechanism includes at least one of retroreflective coating and retroreflective strip.

20. The electronic system configured to determine the proximity of a target object as described in claim 13, characterized in that, The proximity of the target object includes at least one of the following: the distance between the target object and the optical ranging sensor, the position of the target object relative to the optical ranging sensor, and the speed of the target object.

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