Transmitting device for mobile equipment and TOF (Time of Flight) sensor comprising same

Abstract

The utility model provides a transmitting device for mobile equipment and a TOF (Time of Flight) sensor comprising the same. The transmitting device comprises a super lens; a light source; the super lens comprises a substrate and micro-nano structures arranged on the surface of the side, away from the light-emitting face of the light source, of the substrate, and a filling material with the refractive index larger than 1 is arranged between the micro-nano structures. The super lens is used for modulating a light beam emitted by the light source so as to form a light spot on a target plane; the emitting device meets the condition that the air interval between the super lens and the light emitting face of the light source is larger than or equal to 0.1 mm and smaller than or equal to 0.2 mm. The light spot projection of the transmitting device of the TOF sensor can be realized through the super lens, and the volume and the total thickness of the transmitting device are compressed, so that the mobile equipment where the transmitting device is located is more convenient to miniaturize, light and thin.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optics, in particular to a transmitting device for a mobile device and a TOF sensor comprising the same. BACKGROUND

[0002] TOF, Time Of Flight, is a technology for distance measurement by measuring the time in the process of light transmission. A TOF sensor can measure the distance from an object to the sensor according to the time difference between the emitted light and the received light, and is widely used in the field of face recognition.

[0003] However, the transmitting device in the prior art has a large volume, and when the transmitting device in the prior art is applied to a mobile device, it is difficult to ensure the miniaturization and thinness of the mobile device. CONTENT OF THE INVENTION

[0004] One object of the present application is to provide a transmitting device for a mobile device and a TOF sensor comprising the same. The transmitting device for a mobile device and the TOF sensor comprising the same provided by the present application achieve the projection of a light spot through a superlens, compress the volume of the transmitting device, and thus enable the mobile device to be more easily miniaturized and thinned.

[0005] According to an aspect of an embodiment of the present application, a transmitting device for a mobile device is disclosed, characterized in that the transmitting device comprises: a superlens; a light source;

[0006] The superlens comprises a substrate and a micro-nano structure arranged on the surface of the substrate away from the light emitting surface of the light source;

[0007] The superlens is used to modulate the light beam emitted by the light source to form a light spot on a target plane;

[0008] The air gap between the superlens and the light emitting surface of the light source is greater than or equal to 0.1 mm and less than or equal to 0.2 mm.

[0009] In an exemplary embodiment of the present application, a filling material with a refractive index greater than 1 is arranged between the micro-nano structures.

[0010] In an exemplary embodiment of the present application, the transmitting device satisfies TTL≤0.6mm, where TTL is the total optical length of the transmitting device.

[0011] In an example embodiment of the present application, the light beam outputted by the emitting device has a full angle of divergence greater than or equal to 63° and less than or equal to 73° in a first direction, and a full angle of divergence greater than or equal to 49° and less than or equal to 59° in a second direction, wherein the first direction is perpendicular to the second direction.

[0012] In an example embodiment of the present application, the light beam outputted by the emitting device has a full angle of divergence greater than or equal to 55° and less than or equal to 65° in a first direction, and a full angle of divergence greater than or equal to 40° and less than or equal to 50° in a second direction, wherein the first direction is perpendicular to the second direction.

[0013] In an example embodiment of the present application, the emitting device further comprises a substrate, wherein the substrate is configured to support the light source.

[0014] In an example embodiment of the present application, the emitting device further comprises a housing, wherein the housing is disposed on the substrate at a same side as the light source.

[0015] The housing is configured to fix the superlens.

[0016] In an example embodiment of the present application, the total thickness of the emitting device is less than or equal to 0.8 mm.

[0017] In an example embodiment of the present application, the light source is a VCSEL light source.

[0018] According to an aspect of the embodiments of the present application, a TOF sensor is disclosed, which comprises a receiving device and an emitting device as described in any of the above embodiments.

[0019] The emitting device for mobile devices and the TOF sensor comprising the same provided by the present application, the emitting device comprises a superlens, a light source, the superlens comprises a substrate and a micro-nano structure disposed on the surface of the substrate away from the light emitting surface of the light source, the superlens is configured to modulate the light beam emitted by the light source to form a light spot on a target plane, the air gap between the superlens and the light emitting surface of the light source is greater than or equal to 0.1 mm and less than or equal to 0.2 mm. The present application can realize the light spot projection of the emitting device of the TOF sensor through the superlens, which compresses the volume and total thickness of the emitting device, so as to make the mobile device where it is located more convenient for miniaturization and thinning.

[0020] Other characteristics and advantages of the present application will become apparent from the following detailed description, or will be learned by practice of the present application.

[0021] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application, as claimed. BRIEF DESCRIPTION OF DRAWINGS

[0022] The foregoing and other objects, features and advantages of the application will be more readily understood upon consideration of the following detailed description of example embodiments in conjunction with the accompanying drawings.

[0023] Figure 1 A structure schematic diagram of the superlens provided by an embodiment of the application is shown.

[0024] Figure 2 A structure schematic diagram of the transmitting device provided by an embodiment of the application is shown.

[0025] Figure 3 A structure schematic diagram of the transmitting device provided by an embodiment of the application is shown.

[0026] Figure 4 A structure schematic diagram of the transmitting device provided by an embodiment of the application is shown.

[0027] Figure 5 A structure schematic diagram of the receiving device provided by an embodiment of the application is shown.

[0028] Figure 6 A structure schematic diagram of the receiving device provided by an embodiment of the application is shown.

[0029] Figure 7 A structure schematic diagram of the TOF sensor provided by an embodiment of the application is shown.

[0030] REFERENCE NUMERALS:

[0031] 1 - superlens; 11 - substrate; 12 - micro-nano structure; 13 - filling material; 2 - light source; 3 - substrate;

[0032] 4 - shell; 5 - detector; 6 - focusing lens. DETAILED DESCRIPTION

[0033] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, however, can be implemented in many different forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the several views. Like components will not be described repeatedly with like reference numerals.

[0034] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more exemplary embodiments. Numerous specific details are provided in the following description to give a full understanding of exemplary embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced with one or more of the specific details omitted, or other methods, components, steps, etc., can be employed. In other instances, well-known structures, methods, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0035] In existing technologies, diffusers are typically used to modulate the light beam emitted by the light source of the transmitting device in a TOF sensor. However, since the diffuser is usually manufactured using an imprinting process, the substrate of the diffuser needs to have a certain thickness for support; otherwise, the substrate may break. This makes it difficult to compress the thickness of the diffuser. Furthermore, to protect the diffuser, the microlens array on the diffuser can only be placed on the surface of the substrate close to the light-emitting surface of the light source. To ensure that the light emitted from the light-emitting surface of the light source can be received by more microlenses on the microlens array, the air gap between the light-emitting surface of the light source and the diffuser is usually set to be relatively large. Ultimately, the aforementioned two problems directly result in a large overall thickness and volume of the transmitting device. When the transmitting device is used in mobile devices, it is difficult to ensure the miniaturization and thinness of the mobile devices.

[0036] In order to overcome the above-mentioned defects of related technologies, this application provides a transmitting device for mobile devices and a TOF sensor containing the same, which realizes the projection of light spots through a superlens, compresses the volume of the transmitting device, and thus ensures the miniaturization and thinning of the mobile device in which it is located.

[0037] This application provides a transmitting device for a mobile device and a TOF sensor including the same, the transmitting device comprising: a superlens 1; and a light source 2.

[0038] like Figure 1 As shown, Figure 1 A schematic diagram of a superlens provided in an embodiment of this application is shown. The superlens 1 includes a substrate 11 and micro / nano structures 12 disposed on the surface of the substrate 11 facing away from the light-emitting surface of the light source 2. The micro / nano structures 12 are subwavelength structures. The superlens 1 mainly provides corresponding phases at various locations on its surface by configuring parameters such as the material, cross-sectional size, height, and arrangement period of the micro / nano structures 12. This applies a phase abrupt change to the received light beam, thereby creating a certain phase gradient at different positions on the superlens 1, thus modulating the light beam received at different positions on the superlens 1. The superlens 1 is used to modulate the light beam emitted by the light source 2 to form a light spot on the target plane.

[0039] Furthermore, the air gap between the superlens 1 and the light-emitting surface of the light source 2 is greater than or equal to 0.1 mm and less than or equal to 0.2 mm. See details. Figure 2 , Figure 2 This illustration shows a schematic diagram of a transmitting device according to an embodiment of this application. The light source 2 and the substrate 3 in the transmitting device are connected via a power line. Figure 2 The two arcs in the middle are the power lines. In this case, the upper limit of the air gap ensures that the entire transmitting device can be made thin, which greatly reduces the volume of the transmitting device. The lower limit of the air gap can prevent the superlens 1 from colliding with the power line during assembly, which improves the safety of superlens 1 assembly and avoids excessive assembly difficulty.

[0040] In one embodiment, a filling material 13 with a refractive index greater than 1 is provided between the micro / nano structures 12 of the superlens 1. It should be noted that the filling material 13 is a transparent material in the operating wavelength band of the light source 2. Preferably, the filling material 13 is silicon dioxide, wherein the operating wavelength band of the light source 2 is the near-infrared band. In this case, the micro / nano structures 12 of the superlens 1 can be disposed on the surface of the substrate 11 on the side opposite to the light-emitting surface of the light source 2, and the filling material 13 is used to protect the micro / nano structures 12. Furthermore, this arrangement of the micro / nano structures 12 also allows the light beam emitted by the light source 2 to first pass through the substrate 11 and then propagate to the micro / nano structures 12, thereby enabling the light beam to propagate a sufficient distance. While ensuring that the light beam can irradiate more micro / nano structures 12 and ensuring the modulation effect, it also effectively compresses the air gap between the superlens 1 and the light-emitting surface of the light source 2, thereby effectively compressing the volume of the emitting device.

[0041] In one embodiment, the superlens 1 is used to homogenize and collimate the light beam emitted by the light source 2. Specifically, based on the superposition property of the superlens phase, the phase of the superlens 1 includes a homogenizing phase and a collimating phase; wherein, the homogenizing phase is used to diffuse the light beam emitted by the light source 2; and the collimating phase is used to collimate the light beam emitted by the light source 2. That is, the phase distribution of the superlens 1 in this application within its coverage area includes a homogenizing phase for diffusing the light beam and a collimating phase for collimating the light beam. This improves the edge steepness of the light beam modulated by the superlens 1, thereby increasing the edge steepness of the light spot formed by the light beam on the target plane or the object being detected, making the edge of the formed light spot clearer and sharper, and thus improving the accuracy of the transmitting device.

[0042] In one embodiment, the transmitting device satisfies: TTL ≤ 0.6 mm, where TTL is the total optical length of the transmitting device. It should be noted that... Figure 3 A schematic diagram of the structure of a launching device provided in an embodiment of this application is shown, as follows: Figure 2 andFigure 3 As shown, TTL is the distance from the light emitting surface of the light source 2 to the light emitting surface of the superlens 1; and since the height of the micro-nano structure arranged on the substrate 11 is in nanometer level, the height can be ignored, thus in the present application, the light emitting surface of the superlens 1 can be understood as the side of the substrate 11 of the superlens 1 away from the light source 2, that is, TTL is the air gap between the light emitting surface of the light source 2 and the superlens 1 plus the thickness of the substrate 11 of the superlens 1. In this case, the upper limit of TTL can ensure that the emitting device reduces the processing difficulty of the superlens 1 while reducing the volume of the emitting device, which is more conducive to the light and thin of the mobile device.

[0043] It should be further pointed out that the emitting device provided by the present application is applicable to any kind of mobile device, including but not limited to: mobile phone, tablet computer, portable notebook computer, etc.

[0044] In an embodiment, the emitting device also satisfies: TTL≥0.3mm. Since TTL is equivalent to the air gap between the light emitting surface of the light source 2 and the superlens 1 in the emitting device, plus the thickness of the substrate 11 of the superlens 1, therefore, the TTL size of the emitting device can be compressed by reducing the air gap between the light emitting surface of the light source 2 and the superlens 1, or reducing the thickness of the substrate 11 of the superlens 1. The superlens 1 provided by the present application is compared with the homogenizing sheet, since the micro-nano structure 12 can be arranged on the side of the substrate 11 of the superlens 1 away from the light emitting surface of the light source 2, thus the thickness of the substrate 11 of the superlens 1 is also part of the light beam propagation path, the light beam propagates through the air gap and then irradiates into the substrate 11 of the superlens 1, propagates in the substrate 11 and then irradiates onto the micro-nano structure 12 of the superlens 1, in this case, the light beam can still propagate a sufficient distance and irradiate onto as many micro-nano structures 12 as possible, that is, the thickness of the substrate 11 can replace the air gap required by the light beam propagation to ensure the modulation effect of the superlens 1 on the light beam, so as to shorten the air gap between the superlens 1 and the light emitting surface of the light source 2, thus the air gap between the light emitting surface of the light source 2 and the superlens 1 can also be compressed accordingly; in this case, the present application can effectively reduce the TTL of the emitting device, and the reduction of TTL can ensure that the emitting device compresses the volume of the emitting device to the greatest extent on the premise of ensuring the performance, thereby improving the integration of the mobile device where the emitting device is located.

[0045] Moreover, the homogenizing sheet made by the embossing method in the prior art is difficult to reduce the thickness of the homogenizing sheet substrate, while in the present application, the superlens 1 as the optical modulation element of the emitting device can realize the maximum compression of the thickness of the substrate 11 of the superlens 1, in this case, the TTL of the emitting device can also be effectively reduced, and the volume of the emitting device can be compressed.

[0046] In an embodiment, the light beam output by the emitting device has a full angle of divergence in the first direction greater than or equal to 63° and less than or equal to 73°, and a full angle of divergence in the second direction greater than or equal to 49° and less than or equal to 59°, wherein the first direction is perpendicular to the second direction.

[0047] Specifically, in this case, the emitting device is mainly applied to the face recognition function of a mobile device, and the larger full angle of divergence can make the light beam emitted by the emitting device better cover the face of a user, and the larger full angle of divergence can also better adapt to different head postures and angle changes of the user, thereby improving the accuracy of face recognition.

[0048] In an embodiment, the light beam output by the emitting device has a full angle of divergence in the first direction greater than or equal to 55° and less than or equal to 65°, and a full angle of divergence in the second direction greater than or equal to 40° and less than or equal to 50°, wherein the first direction is perpendicular to the second direction.

[0049] Specifically, in this case, the emitting device is mainly applied to the ranging function of a mobile device, and the smaller full angle of divergence can make the light beam emitted by the emitting device more concentrated, so that the light beam can be projected farther, thereby increasing the effective range of ranging and improving the accuracy of ranging.

[0050] It should be noted that in the foregoing embodiments regarding the full angle of divergence, the first direction and the second direction are specifically as shown in the coordinate axes in Figure 2 , the first direction refers to the x-axis direction, and the second direction refers to the y-axis direction.

[0051] In an embodiment, the emitting device further comprises a substrate 3, the substrate 3 being configured to carry the light source 2. Preferably, the substrate 3 is made of ceramic. The substrate 3 is further configured to provide a driving current for the light source 2, so that the light source 2 can work.

[0052] In an embodiment, the emitting device further comprises a housing 4, the housing 4 being arranged on the substrate 3 on the same side as the light source 2, as shown in Figure 2 and Figure 3 . The housing 4 is further configured to fix the superlens 1; it should be noted that in some embodiments of the present application, as shown in Figure 2 and Figure 3 , the superlens 1 is arranged at the edge of the housing 4, which can facilitate the assembly of the superlens 1 and reduce the processing difficulty of the emitting device; in other embodiments of the present application, as shown in Figure 4 , the superlens 1 is arranged inside the space surrounded by the housing 4, which can better protect the superlens 1 and prolong the service life of the emitting device. Figure 4 , the superlens 1 is arranged inside the space surrounded by the housing 4, which can better protect the superlens 1 and prolong the service life of the emitting device.

[0053] In one embodiment, the total thickness of the transmitting device is less than or equal to 0.8 mm. For example... Figure 2 and Figure 3 As shown, the total thickness of the emitting device refers to the distance from the side of the substrate 3 facing away from the light-emitting surface of the light source 2 to the farthest point away from the light-emitting surface of the light source 2. It should be noted that the farthest point away from the light-emitting surface of the light source 2 can be the light-emitting surface of the superlens 1 or the highest point of the outer surface of the housing 4. In this case, the total thickness of the emitting device can be limited to a small range, which takes into account both the overall assembly difficulty of the emitting device and ensures that the thickness of the emitting device is within a relatively thin range.

[0054] In one embodiment, the total thickness of the transmitting device is greater than or equal to 0.6 mm. In this case, the thickness of the transmitting device can be compressed to the maximum extent, that is, the volume of the transmitting device can also be compressed to the maximum extent, thereby enabling the mobile device in which it is located to be better miniaturized and made thinner.

[0055] In one embodiment, the light-emitting surface of the superlens 1 of the emitting device is higher than the outer surface of the housing 4, such as... Figure 2 As shown, the total thickness is the distance from the side of the substrate 3 facing away from the light-emitting surface of the light source 2 to the light-emitting surface of the superlens 1. In other words, the total thickness of the emitting device is actually the sum of the thickness of the substrate 4, the thickness of the light source 2, the air gap between the light-emitting surface of the light source 2 and the superlens 1, and the thickness of the substrate 11 of the superlens 1. It should be noted that although the superlens 1 also includes a filling material 13, since the filling material 13 is also nanometer-scale in height, it can be ignored. The light-emitting surface of the superlens 1 is still considered as the side of the substrate 11 facing away from the light source 2. In this case, the assembly difficulty of the superlens 1 can be effectively reduced, while simultaneously protecting the micro / nano structures 12 on the superlens 1.

[0056] In one embodiment, the light-emitting surface of the superlens 1 of the emitting device is lower than the height of the outer surface of the housing 4, such as... Figure 3 As shown, the total thickness is the distance from the side of the substrate 3 facing away from the light-emitting surface of the light source 2 to the highest point of the outer surface of the housing 4. In other words, the total thickness of the emitting device is actually the sum of the thickness of the substrate 4 and the height of the outer surface of the housing 4. In this case, the light-emitting surface of the superlens 1 does not need to be filled with filling material 13, thereby reducing the manufacturing cost of the superlens 1 and improving the safety of the superlens 1. However, in the mass production and processing of the emitting device, the superlens 1 without filling with protective material is prone to damage to the micro-nano structure 12 during processing. Therefore, it is preferable to use filling material 13 between the micro-nano structures 12 as described in the aforementioned embodiment to protect the micro-nano structures 12.

[0057] In an embodiment, the light source 2 in the emitting device is a VCSEL (Vertical-Cavity Surface-Emitting Laser) light source.

[0058] The present application also provides a TOF sensor for a mobile device, the TOF sensor comprising: a receiving device; and an emitting device as described in the above embodiments.

[0059] Specifically, the receiving device comprises a detector 5, as shown in Figure 5 , Figure 5 A structural schematic diagram of the receiving device provided by an embodiment of the present application is shown in the figure, and the detector 5 is used to receive and sense the light spot projected on the target plane by the emitting device. After the emitting device emits the light beam and forms the light spot at the target plane or the detection object, the reflected light beam reflected by the light spot can be received by the detector 5 carried on the receiving device, that is, the detector 5 on the receiving device can sense the light spot, so that the TOF sensor can determine the distance, shape or posture of the target plane or the detection object based on the light spot sensed by the detector 5 on the receiving device.

[0060] It should be noted that the receiving device also comprises a corresponding housing and substrate (not marked in the figure).

[0061] In an embodiment, the receiving device further comprises a focusing lens 6.

[0062] Specifically, as shown in Figure 6 , Figure 6 A structural schematic diagram of the receiving device provided by an embodiment of the present application is shown in the figure, and the focusing lens 6 is used to converge the reflected light beam reflected by the target plane, and the received reflected light beam is converged, so that the converged reflected light beam can be emitted to the detector 5 by the focusing lens 6. In this case, the reflected light beam reflected by the target plane can be better accepted by the detector 5, thereby improving the measurement accuracy of the TOF sensor.

[0063] In an embodiment, the emitting device and the receiving device in the TOF sensor can be arranged at different positions, as long as the receiving device can receive the reflected light beam of the light spot projected by the emitting device.

[0064] In an embodiment, the emitting device and the receiving device of the TOF sensor can be arranged side by side, as shown in Figure 7 , Figure 7 A structural schematic diagram of the TOF sensor provided by an embodiment of the present application is shown in the figure, and in this case, the housing 4 of the emitting device is tightly attached to the housing (not marked in the figure) of the receiving device, thereby improving the integration of the TOF sensor.

[0065] Embodiments

[0066] In this embodiment, the thickness of the superlens 1 is 0.3 mm, the light source 2 is a VCSEL light source, the thickness of the light source 2 is 0.1 mm, the air gap between the superlens 1 and the light emitting surface of the light source 2 is 0.2 mm, the material of the substrate 3 is ceramic, the thickness of the substrate 3 is 0.2 mm, the total thickness of the entire emitting device is 0.8 mm (without considering the thickness of the glue used to fix the VCSEL light source), the TTL of the emitting device is 0.5 mm, the full angle of the divergence angle of the light beam output by the emitting device in the first direction is 68°, and the full angle of the divergence angle in the second direction is 54° (alternatively, the full angle of the divergence angle of the light beam output by the emitting device in the first direction is 60°, and the full angle of the divergence angle in the second direction is 45°).

[0067] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

Claims

1. A transmitting apparatus for a mobile device, characterized by, The emitting device comprises: a superlens; a light source; The superlens comprises a substrate and micro-nano structures arranged on the surface of the substrate away from the light emitting surface of the light source; The superlens is used for modulating the light beam emitted by the light source to form a light spot on a target plane; The air gap between the superlens and the light emitting surface of the light source is greater than or equal to 0.1 mm and less than or equal to 0.2 mm.

2. The transmitting apparatus of claim 1, wherein, The micro-nano structures are provided with a filling material with a refractive index greater than 1.

3. The launch device of claim 1, wherein, The superlens is used for homogenizing and collimating the light beam emitted by the light source.

4. The launch device of claim 1, wherein, The emitting device satisfies: TTL≤0.6mm, wherein TTL is the total optical length of the emitting device.

5. The launch device of claim 1, wherein, The light beam output by the emitting device has a total angle of divergence greater than or equal to 63° and less than or equal to 73° in a first direction and a total angle of divergence greater than or equal to 49° and less than or equal to 59° in a second direction, wherein the first direction is perpendicular to the second direction.

6. The transmitting apparatus of claim 1, wherein, The light beam output by the emitting device has a total angle of divergence greater than or equal to 55° and less than or equal to 65° in a first direction and a total angle of divergence greater than or equal to 40° and less than or equal to 50° in a second direction, wherein the first direction is perpendicular to the second direction.

7. The launch device of claim 1, wherein, The emitting device further comprises: a substrate; the substrate is used to carry the light source.

8. The launch device of claim 1, wherein, The emitting device further comprises: a housing; the housing is arranged on the substrate on the same side as the light source; The housing is used to fix the superlens.

9. The launch device of claim 1, wherein, The total thickness of the emitting device is less than or equal to 0.8 mm.

10. A TOF sensor, characterized by The TOF sensor comprises: a receiving device; the emitting device according to any one of claims 1-9.

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