WO2021081865A1

WO2021081865A1 - Optical diffuser, light emitting module, mobile terminal, and method for manufacturing optical diffuser

Info

Publication number: WO2021081865A1
Application number: PCT/CN2019/114584
Authority: WO
Inventors: 丁细超; 沈培逸; 李宗政
Original assignee: 南昌欧菲生物识别技术有限公司
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2021-05-06

Abstract

An optical diffuser (30), a light emitting module (1), a mobile terminal, and a method for manufacturing the optical diffuser. The optical diffuser (30) comprises: a diffusion sheet (100); and an ITO layer (200), disposed inside the diffusion sheet (100).

Description

Optical diffuser, light emitting module, mobile terminal and manufacturing method of optical diffuser

Technical field

The present disclosure relates to the field of imaging technology, in particular to an optical diffuser, a light emitting module having the optical diffuser, a mobile terminal having the light emitting module, and a manufacturing method of the optical diffuser.

Background technique

The TOF (Time of Flight) module 1'in the related art, as shown in Figure 1, if the optical diffuser (Diffuser) 10' in the module breaks, it will cause the VCSEL (Vertical Cavity Surface Emitting Laser) light source 20' Hit human eyes directly, causing eye damage. For this reason, a photodiode (PD) 30' is usually added to the module to receive the reflected light from the optical diffuser 10', and the magnitude of the photocurrent generated by it is monitored to determine whether the optical diffuser 10' is broken, but this solution The following problems exist:

Due to the addition of the photodiode 30', the cost of the TOF module 1'increases;

Since the module needs to even out the position where the photodiode 30' is installed, the overall volume of the module 1'is relatively large;

Since the photodiode 30' indirectly reflects whether the optical diffuser 10' is broken by the current value generated by the conversion of reflected light, it is necessary to strictly control the range of the current value of the photodiode 30' for monitoring. However, the intensity of the reflected light on the surface of the photodiode 30' is greatly affected by the PD-VCSEL/PD-Diffuser spacing. Due to the large process deviation, the PD current value of some modules exceeds the control range, which causes the module to misjudge. The manufacturing process is difficult, which affects the production yield of the module 1'.

Summary of the invention

The present disclosure aims to solve at least one of the technical problems existing in the prior art. To this end, an objective of the present disclosure is to provide an optical diffuser that can accurately determine whether a crack occurs, and has a low cost, which is beneficial to reduce the volume of the module, reduce the difficulty of the manufacturing process, and improve the production yield of the module.

The present disclosure also proposes a light emitting module with the above-mentioned optical diffuser.

The present disclosure also proposes a mobile terminal with the above-mentioned light emitting module.

The present disclosure also proposes a manufacturing method of the light emitting module.

According to an embodiment of the first aspect of the present disclosure, an optical diffuser is provided. The optical diffuser includes: a diffusion sheet; and an ITO layer, the ITO layer being disposed inside the diffusion sheet.

According to the optical diffuser of the embodiment of the present disclosure, by providing an ITO layer inside the diffuser, it is possible to feedback whether the optical diffuser is broken according to the resistance change of the ITO layer, and because the ITO layer 200 is placed inside the diffuser, it can prevent The ITO layer is damaged during the manufacturing and transportation process, so as to accurately and reliably feedback whether the optical diffuser is broken, reducing the possibility of misjudgment. Based on this, there is no need to install a photodiode in the light emitting module, which effectively reduces the cost and reserves design space for the miniaturization of the light emitting module. In addition, the difficulty of the manufacturing process can be reduced, thereby increasing the production yield.

According to some specific embodiments of the present disclosure, the diffusion sheet has an optically effective area, and the ITO layer is arranged around the edge of the optically effective area. Thus, while realizing monitoring, it does not affect the spread of light.

According to some specific embodiments of the present disclosure, the diffusion sheet includes a substrate and a diffusion layer, and the ITO layer is disposed between the substrate and the diffusion layer. As a result, the ITO layer was built into the diffusion sheet.

Further, the ITO layer is plated on the substrate, and the diffusion layer is combined with the ITO layer through a transfer glue. In this way, the overall structure of the diffusion sheet is stable and the process is simple.

Further, the ITO layer includes: an open loop portion extending along the circumferential direction of the substrate and spaced a predetermined distance from the outer edge of the substrate; a first detection portion and a second detection portion, the The first detection portion extends from one end of the open loop portion to the outer edge of the substrate, and the second detection portion extends from the other end of the open loop portion to the outer edge of the substrate. A detection part and the second detection part are spaced apart and located on the same side of the substrate. As a result, it is not only possible to provide timely feedback through the change of the resistance value when the optical diffuser is broken, but also to facilitate the detection of the resistance value of the ITO layer.

According to some specific embodiments of the present disclosure, the thickness of the ITO layer is less than or equal to 500 nm. This can reduce the impact on the imprinting effect of the microstructure layer.

An embodiment according to the second aspect of the present disclosure provides a light emitting module, the light emitting module includes: a base; a VCSEL light source, the VCSEL light source is provided on the base; according to the first aspect of the present disclosure In the optical diffuser of the embodiment, the optical diffuser is provided on the base.

The light emitting module according to the embodiment of the present disclosure, by using the optical diffuser according to the embodiment of the first aspect of the present disclosure, has the advantages of high safety, low cost, small size, low process difficulty, and high production yield. .

According to some specific embodiments of the present disclosure, the light emitting module further includes: a resistance detection device connected to the ITO layer. This facilitates monitoring of the resistance of the ITO layer.

Further, a connecting wire is provided in the base, and the ITO layer is connected to the resistance detection device through the connecting wire. This facilitates monitoring of the resistance of the ITO layer.

Further, the base is configured with a supporting step, the diffusion sheet is mounted on the supporting step through a conductive pad, and the ITO layer and the connecting line are connected through the conductive pad. This realizes the fixation of the diffusion sheet and facilitates the monitoring of the resistance of the ITO layer.

Further, the conductive pad is attached to the supporting step by a conductive adhesive. In this way, while improving the structural stability, it further facilitates the monitoring of the resistance of the ITO layer.

According to some specific embodiments of the present disclosure, the light emitting module further includes a controller, which is respectively connected to the resistance detection device and the VCSEL light source, and when the resistance detection device detects the ITO When the resistance of the layer increases by a predetermined value, the controller turns off the power of the VCSEL light source. In this way, the automatic judgment of whether the optical diffuser is broken is realized.

According to an embodiment of the third aspect of the present disclosure, a mobile terminal is provided, and the mobile terminal includes the light emitting module according to the embodiment of the second aspect of the present disclosure.

The mobile terminal according to the embodiment of the present disclosure, by using the light emitting module according to the embodiment of the second aspect of the present disclosure, has the advantages of high safety, low cost, small size, low process difficulty, and high production yield.

An embodiment according to the fourth aspect of the present disclosure proposes a method of manufacturing an optical diffuser. The method of manufacturing the optical diffuser includes: determining the size and cutting interval of the optical diffuser; and according to the size of the optical diffuser And the cutting interval, ITO layer is plated on one side of the substrate; transfer glue is coated on the ITO layer; the master mold containing the diffusion layer is attached; after pre-curing, the mold is demolded and cured and cut.

According to the manufacturing method of the optical diffuser according to the embodiment of the present disclosure, it can accurately determine whether a crack occurs, and the cost is low, which is beneficial to reduce the volume of the module, reduce the difficulty of the manufacturing process, and improve the production yield of the module.

The additional aspects and advantages of the present disclosure will be partially given in the following description, and some will become obvious from the following description, or be understood through the practice of the present disclosure.

Description of the drawings

The above and/or additional aspects and advantages of the present disclosure will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

FIG. 1 is a schematic diagram of the structure of a light emitting module in the prior art.

Fig. 2 is a schematic structural diagram of a light emitting module according to an embodiment of the present disclosure.

Fig. 3 is a schematic structural diagram of an optical diffuser according to an embodiment of the present disclosure.

4 is a schematic diagram of the ITO layer distribution of the optical diffuser according to an embodiment of the present disclosure.

FIG. 5 is a flowchart of a method of manufacturing an optical diffuser according to an embodiment of the present disclosure.

Reference signs:

current technology:

TOF module 1', optical diffuser 10', VCSEL light source 20', photodiode 30';

This disclosure:

Light emitting module 1,

Base 10, VCSEL light source 20, optical diffuser 30, supporting step 40, conductive pad 50, conductive glue 60, diffuser 100, substrate 110, master 120, transfer glue 130,

The ITO layer 200, the open loop portion 210, the first detection portion 220, and the second detection portion 230.

Detailed ways

The embodiments of the present disclosure are described in detail below. Examples of the embodiments are shown in the accompanying drawings, in which the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary, and are only used to explain the present disclosure, and should not be construed as limiting the present disclosure.

In the description of the present disclosure, it should be understood that the terms "center", "length", "width", "thickness", "top", "bottom", "inner", "outer", "circumferential", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the pointed device or element must have a specific orientation or a specific orientation. The structure and operation cannot therefore be construed as a limitation of the present disclosure.

The light emitting module 1 according to an embodiment of the present disclosure will be described below with reference to the accompanying drawings.

As shown in FIG. 2, the light emitting module 1 according to the embodiment of the present disclosure includes a base 10, a VCSEL light source 20 and an optical diffuser 30.

First, the optical diffuser 30 according to an embodiment of the present disclosure will be described with reference to FIGS. 3 and 4.

The optical diffuser 30 according to an embodiment of the present disclosure includes a diffusion sheet 100 and an ITO (Indium Tin Oxide) layer 200. The ITO layer 200 is provided inside the diffusion sheet 100, that is, the ITO layer 200 is built in the diffusion sheet 100.

In the light emitting module 1 according to the embodiment of the present disclosure, the VCSEL light source 20 is provided on the base 10, and the optical diffuser 30 is provided on the base 10. For example, the base 10 may be a ceramic piece, the base 10 is configured with a groove, the VCSEL light source 20 is located in the groove and arranged at the center of the bottom wall of the groove, and the optical diffuser 30 covers the groove of the base 10, And the optical effective area of the optical diffuser 30 is directly opposite to the VCSEL light source 20.

According to the light emitting module 1 and the optical diffuser 30 of the embodiment of the present disclosure, by arranging the ITO layer 200 inside the diffuser 100, it is possible to feedback whether the optical diffuser 30 is broken according to the resistance change of the ITO layer 200. The layer 200 is placed inside the diffusion sheet 100, which can prevent the ITO layer 200 from being damaged during the manufacturing and transportation process, thereby accurately and reliably feedback whether the optical diffuser 30 is broken, and reducing the possibility of misjudgment. Based on this, there is no need to install a photodiode in the light emitting module 1, which effectively reduces the cost and reserves design space for the miniaturization of the light emitting module 1. For example, the size of the light emitting module 1'in the prior art A′ is usually 4.2 mm, and the size A of the light emitting module 1 according to the embodiment of the present disclosure can be reduced to 3.6 mm or even smaller. In addition, the difficulty of the manufacturing process can be reduced, thereby increasing the production yield.

Therefore, the optical diffuser 30 according to the embodiment of the present disclosure can accurately determine whether a crack occurs, and the cost is low, which is beneficial to reduce the volume of the module, reduce the difficulty of the manufacturing process, and improve the production yield of the module.

The light emitting module 1 according to the embodiment of the present disclosure, by using the optical diffuser 30 according to the above embodiment of the present disclosure, has the advantages of high safety, low cost, small size, low process difficulty, and high production yield.

In some specific embodiments of the present disclosure, as shown in FIG. 4, the diffuser 100 has an optically effective area. It can be understood here that the optically effective area refers to the part through which light can actually pass, and is usually set in the center of the diffuser 100. At this point, the ITO layer 200 is arranged around the edge of the optical effective area, so as to realize monitoring without affecting the propagation of light.

In some specific examples of the present disclosure, as shown in FIG. 3, the diffusion sheet includes a substrate 110 and a diffusion layer 120. The ITO layer 200 is disposed between the substrate 110 and the diffusion layer 120. For example, the ITO layer 200 is electroplated on the substrate 110. , The diffusion layer 120 is combined with the ITO layer 200 through the transfer glue 130. In this way, the ITO layer 200 is built in the diffusion sheet 100.

Specifically, as shown in FIG. 4, the ITO layer 200 includes an open loop part 210, a first detection part 220 and a second detection part 230.

The open-loop portion 210 is a ring with an opening, for example, a rectangular open-loop shape matching the outer edge of the substrate 110 is formed. The open-loop portion 210 extends along the circumferential direction of the substrate 110, and the open-loop portion 210 is spaced from the outer edge of the substrate 110 A predetermined distance, which is usually not zero. The first detection portion 220 extends from one end of the open loop portion 210 to the outer edge of the substrate 110, and the second detection portion 230 extends from the other end of the open loop portion 210 to the outer edge of the substrate 110. The first detection portion 220 and the second The two detecting parts 230 are spaced apart and located on the same side of the substrate 110. In this way, not only can the optical diffuser 30 be broken in time through the resistance change for feedback, but also the arrangement of the first detection part 220 and the second detection part 230 can facilitate the detection of the resistance value of the ITO layer 200.

In some specific embodiments of the present disclosure, the light emitting module 1 further includes a resistance detection device (not shown in the figure) and a controller (not shown in the figure), and the resistance detection device is connected to the ITO layer 200, so The controller is connected to the resistance detection device and the VCSEL light source 20 respectively.

Specifically, a connecting wire (such as a metal wire) is provided in the base 10, and the ITO layer 200 is connected to the resistance detection device through the connecting wire. For example, the base 10 is configured with a supporting step 40, the diffusion sheet 100 is mounted on the supporting step 40 through a conductive pad 50, and the conductive pad 50 is attached to the supporting step 40 through a conductive glue 60 (such as silver glue), thereby The first detection part 220 and the second detection part 230 of the ITO layer 200 are connected to the resistance detection device through the conductive pad 50, the conductive glue 60 and the connecting wire in sequence.

When the optical diffuser 30 is cracked, the ITO layer 200 at the cracked position is broken, and the circuit is opened. The resistance detection device monitors that the resistance of the ITO layer 200 rises suddenly, thereby judging that the optical diffuser 30 is broken. Alternatively, when the optical diffuser 30 falls off, the connection line inside the base 10 at the conductive pad 50 is disconnected, and the resistance detection device can also monitor the increase in the resistance of the ITO layer 200 to determine that the optical diffuser 30 falls off. In either case, when it is monitored that the resistance of the ITO layer 200 rises and the rise reaches a predetermined value, the controller turns off the VCSEL light source 20 to avoid concentrated light emission and endanger human eye safety.

Those skilled in the art can understand that the resistance detection device and the controller may be externally placed on the base 10, for example, integrated on the circuit board of the device to which the light emitting module 1 is applied.

Hereinafter, a method of manufacturing an optical diffuser according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

As shown in FIG. 5, the method of manufacturing an optical diffuser according to an embodiment of the present disclosure includes:

S1: Determine the size and cutting interval of the optical diffuser;

S2: According to the size and cutting interval of the optical diffuser, plate an ITO layer on one side of the substrate;

S3: Coating transfer glue on the ITO layer;

S4: Fit the master mold containing the diffusion layer;

S5: After pre-curing, demoulding, curing and cutting are carried out.

Specifically, first confirm the size and cutting interval of the required optical diffuser 30, and plate the ITO layer 200 on one side of the substrate 110 (such as white glass) according to the above information, and then coat the transfer glue 130 on the ITO layer 200, The diffusion layer 120 is attached to it, after pre-curing, it is demolded and further cured and cut. The thickness of the ITO layer 200 is less than or equal to 500 nm, so the impact on the imprinting effect of the microstructure layer is minimal.

The following describes a mobile terminal according to an embodiment of the present disclosure. The mobile terminal includes the light emitting module 1 according to the above-mentioned embodiment of the present disclosure. The mobile terminal may be a mobile phone, a tablet computer, or the like.

The mobile terminal according to the embodiment of the present disclosure, by using the light emitting module 1 according to the above-mentioned embodiment of the present disclosure, has the advantages of high safety, low cost, small size, low process difficulty, and high production yield.

Other configurations and operations of the mobile terminal according to the embodiments of the present disclosure are known to those of ordinary skill in the art, and will not be described in detail here.

In the description of this specification, the description with reference to the terms "specific embodiment", "specific example", etc. means that the specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or In the example. In this specification, the schematic representation of the above-mentioned terms does not necessarily refer to the same embodiment or example.

Although the embodiments of the present disclosure have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and modifications can be made to these embodiments without departing from the principle and purpose of the present disclosure. The scope of the present disclosure is defined by the claims and their equivalents.

Claims

An optical diffuser, characterized in that it comprises:

Diffuser

The ITO layer is arranged inside the diffusion sheet.
The optical diffuser according to claim 1, wherein the diffusion sheet has an optically effective area, and the ITO layer is arranged around an edge of the optically effective area.
The optical diffuser according to claim 1, wherein the diffusion sheet comprises a substrate and a diffusion layer, and the ITO layer is disposed between the substrate and the diffusion layer.
4. The optical diffuser of claim 3, wherein the ITO layer is plated on the substrate, and the diffusion layer is combined with the ITO layer through a transfer glue.
The optical diffuser of claim 4, wherein the ITO layer comprises:

An open-loop portion, the open-loop portion extends along the circumferential direction of the substrate and is spaced apart from the outer edge of the substrate by a predetermined distance;

A first detection portion and a second detection portion, the first detection portion extends from one end of the open loop portion to the outer edge of the substrate, and the second detection portion extends from the other end of the open loop portion To the outer edge of the substrate, the first detection portion and the second detection portion are spaced apart and located on the same side of the substrate.
The optical diffuser of claim 1, wherein the thickness of the ITO layer is less than or equal to 500 nm.
A light emitting module is characterized in that it comprises:

Base

VCSEL light source, the VCSEL light source is arranged on the base;

The optical diffuser according to any one of claims 1 to 6, wherein the optical diffuser is provided on the base.
8. The light emitting module of claim 7, further comprising:

The resistance detection device is connected to the ITO layer.
8. The light emitting module according to claim 8, wherein a connecting wire is provided in the base, and the ITO layer is connected to the resistance detection device through the connecting wire.
The light emitting module according to claim 9, wherein the base is configured with a supporting step, the diffusion sheet is installed on the supporting step through a conductive pad, and the ITO layer is connected to the connection The wires communicate through the conductive pads.
10. The light emitting module of claim 10, wherein the conductive pad is attached to the supporting step by a conductive adhesive.
The light emitting module according to any one of claims 8-11, further comprising:

A controller, the controller is respectively connected with the resistance detection device and the VCSEL light source, when the resistance detection device monitors that the resistance of the ITO layer rises by a predetermined value, the controller turns off the VCSEL light source Power supply.
A mobile terminal, characterized by comprising the light emitting module according to any one of claims 7-12.
A method for manufacturing an optical diffuser, which is characterized in that it comprises:

Determining the size and cutting interval of the optical diffuser;

According to the size and cutting interval of the optical diffuser, an ITO layer is plated on one side of the substrate;

Coating transfer glue on the ITO layer;

Laminate the master mold containing the diffusion layer;

After pre-curing, it is demoulded and cured and cut.