TWM611072U - Optical proximity sensor module and apparatus including the module - Google Patents

Abstract

An apparatus includes a display screen, and an optical proximity sensor module disposed behind the display screen. The optical proximity sensor module includes a light emitter operable to produce light having a wavelength for transmission through the display screen toward a target object, and a light sensor operable to sense light reflected by the target object and having the wavelength. The optical proximity sensor module can includes means for reducing a maximum energy density of a light beam produced by the light emitter. The means for reducing the maximum energy density of the light beam is disposed between the light emitter and the display screen so as to intersect the light beam produced by the light emitter. In some cases, there are multiple light emitters collectively operable to provide sufficient optical energy for proximity sensing without producing a visible spot on the display screen. These and other techniques can help reduce or eliminate display screen distortion caused by energy from the light emitters.

Description

Optical proximity sensor module and equipment containing the module

This creation is about optical proximity sensing system.

One of the recent trends in the industrial design of smart phones is to reduce the bezel width and remove the remaining holes for the optical sensor and other holes for the microphone, speaker, and/or fingerprint reader. The border area clears clutter and maximizes the screen area. On the other hand, there is also a trend of increasing the number of optical sensors to obtain additional functionality. For example, in some cases, an optical proximity sensor is integrated into the smart phone to facilitate adjustment of the display screen brightness and reduce the overall energy consumption of the display when the user brings the smart phone close to her ear. Optical proximity sensing usually relies on emitting infrared (IR) or near infrared (NIR) light and measuring the light energy reflected back from the object to be detected.

Another trend in the smart phone market is the use of organic light-emitting displays (OLED). This trend provides an opportunity to move the proximity sensor from the frame of the smart phone to a position below the OLED. Therefore, the proximity sensor is buried behind the OLED, which allows certain light including IR and NIR radiation to pass through. However, the energy of IR or NIR light sometimes causes screen distortion (for example, a bright spot on an OLED screen, which can be visible under certain conditions), even when the screen displays a black image.

This creation describes the technology used to help reduce or eliminate the distortion of the display screen caused by the energy from the light emitter in a proximity sensor module.

According to one aspect of the present creation, an optical proximity sensor module is provided, which includes: a light emitter operable to generate light having a wavelength, and the light transmits through the display screen toward a target object; A light sensor, which is operable to sense light reflected by the target object and having the wavelength; and a member for reducing one of the maximum energy density of a light beam generated by the light emitter, which is used for reducing The member of the maximum energy density of the light beam is arranged between the light emitter and the display screen so as to intersect the light beam generated by the light emitter.

According to another aspect of the present creation, an optical proximity sensor module configured to be placed behind a display screen of a device is provided. The optical proximity sensor module includes: a plurality of light emitters, which Operable to generate infrared or near-infrared light, the infrared or near-infrared light is transmitted through the display screen toward a target object; and a light sensor, which is operable to sense the infrared or near-infrared light reflected by the target object . The plurality of light emitters are collectively operable to provide sufficient optical energy for the proximity sensing, and the light emitters disperse the optical energy for the proximity sensing, thereby reducing distortion of the display screen.

According to still another aspect of the present creation, a method is provided, which includes: causing each of a plurality of VCSELs in an optical proximity sensor module disposed behind a display screen to generate infrared or near-infrared light , The infrared or near-infrared light is transmitted through the display screen toward a target object, wherein each of the VCSELs generates an energy level of 2.0mW or less; sensing the infrared or near-infrared light reflected by the target object Light; and processing the signal corresponding to the sensed infrared or near-infrared light for proximity sensing.

For example, in one aspect, this creation describes a device that includes a display screen and an optical proximity sensor module arranged behind the display screen. The optical proximity sensor module includes: a light emitter operable to generate light having a wavelength, and the light transmits through the display screen toward a target object; and a light sensor operable to sense Measure the light reflected by the target object and having the wavelength. The optical proximity sensor module also includes a component for reducing the maximum energy density of a light beam generated by the light emitter. The member for reducing the maximum energy density of the light beam is arranged between the light emitter and the display screen so as to intersect the light beam generated by the light emitter.

Certain implementations include one or more of the following features. For example, in some cases, the display screen is an OLED display screen. For example, the member for reducing the maximum energy density of the light beam may include a microlens, a microlens array, and/or an optical diffuser. The member for reducing the maximum energy density of the light beam is operable to cause the light beam to propagate radially so as to reduce the maximum energy density of the light beam incident on the OLED screen. In some embodiments, a beam of the member emitted to reduce the maximum energy density of the beam has a half beam and a half width larger than the beam emitted by the light emitter. In some cases, the light emitter is operable to generate infrared or near-infrared light.

According to another aspect, this creation describes a device that includes a display screen and an optical proximity sensor module arranged behind the display screen. The optical proximity sensor module includes: a plurality of light emitters operable to generate infrared or near-infrared light, the infrared or near-infrared light is transmitted toward a target object through the display screen; and a light sensor, It can be operated to sense infrared or near-infrared light reflected by the target object. The light emitters are collectively operable to provide sufficient optical energy for proximity sensing. In particular, the light emitters disperse the optical energy used for the proximity sensing, thereby reducing the display screen’s distortion.

In some cases, each of the light emitters is operable to generate an energy density, so as to reduce one of the maximum energy density of light incident on a back side of the display screen, while maintaining the total energy In order to promote the performance of the proximity test. For example, the display screen can be an OLED display screen.

This creation also describes a method that includes: causing each of a plurality of VCSELs in an optical proximity sensor module arranged behind a display screen to generate infrared or near-infrared light, the infrared or near-infrared light The light is transmitted through the display screen toward a target object. Each of the VCSELs generates a maximum energy level of 2.0 mW, and preferably a maximum energy level of 1.5 mW. The method further includes: sensing infrared or near-infrared light reflected by the target object; and processing a signal corresponding to the sensed infrared or near-infrared light for proximity sensing. In some embodiments, the method includes: applying a drive current in a range of 2 mA to 3 mA to each of the plurality of VCSELs. In some cases, these methods can help eliminate or reduce screen distortion.

It will be easy to understand other aspects, features and advantages based on the following detailed description, drawings and the scope of the patent application.

10: Host device

12: Display screen

14: Optical proximity sensor module

16: Electronic control unit

20: front glass

22: Launcher

24: light sensor

26: Micro lens array

26A: Round micro lens

26B: Hexagonal micro lens

28: beam

30: beam

32: optical components

34: printed circuit board

114: Proximity sensor module

d1: spacing

d2: spacing

Figure 1 illustrates various features of a host device including an optical proximity sensor module located behind a display screen.

Figure 2 illustrates the details of the optical proximity sensor module according to a first embodiment.

Figure 3A illustrates further details of the proximity sensor of Figure 2 according to certain implementations.

Fig. 3B is a top view of Fig. 3A.

Fig. 3C is a cross-sectional view passing through the line A-A of Fig. 3B.

Figure 4 illustrates a first example of a microlens array.

Figure 5 illustrates a second example of a microlens array.

Figure 6 illustrates the details of the optical proximity sensor module according to a second embodiment.

FIG. 7 illustrates the details of the optical proximity sensor module according to a third embodiment.

As shown in FIG. 1, a host device 10 (such as a portable computing device (eg, a smart phone, personal digital assistant (PDA), laptop, or wearable)) includes a front glass An OLED type or other display screen 12 below 20. An optical proximity sensor module 14 is arranged directly below a part of the display screen 12 and is operable to emit light (for example, infrared or near infrared radiation) toward a target object outside the host device 10 and sense the direction from the target object The light reflected back by the optical proximity sensor module 14.

An electronic control unit (ECU) 16 is operable to receive, process, and analyze the signal from the optical proximity sensor module 14, and in response, execute a designation depending on, for example, the amount of light detected action. In some cases, for example, the ECU 16 may cause the brightness of the display screen 12 to be adjusted. In some cases, the detection/release event is interrupt-driven and occurs when the proximity result exceeds the upper threshold setting and/or the lower threshold setting. For example, the ECU 16 may be a processor used in the sensor hub or some other processor in the host device 10. The overall brightness of the OLED can be controlled, for example, by using a transistor in series with the pixels to apply PWM modulation to each pixel or by adjusting the overall range of current that can drive each pixel.

As shown in the example of FIG. 2, the optical proximity sensor module 14 includes an emitter 22, such as being operable to emit IR or NIR radiation (for example, at a wavelength of 940 nm) A light emitting diode (LED) or a vertical cavity surface emitting laser (VCSEL), and a factory-calibrated LED driver. The optical proximity sensor module 14 also includes a photo sensor 24, such as a photodiode receiver, operable to sense light having the same wavelength emitted by the transmitter 22. The photodiode receiver may include associated circuitry operable to process signals from the photodiode. Each of the transmitter 22 and the light sensor 24 can be, for example, implemented as a separate die (ie, semiconductor chip) and can be mounted on a printed circuit board 34 (or other substrate) .

Some light emitters produce a light beam whose energy density is roughly shaped like a bell-shaped curve, that is, its energy density has a maximum value at or close to the central optical axis of the emitter, and varies with Decrease with the distance from the center optical axis. The maximum energy density generated by the transmitter 22 may be sufficiently high to cause a distortion on the display screen 12 (if no steps are taken to prevent this distortion).

As further illustrated in the example of FIG. 2, the optical proximity sensor module 14 includes a component for reducing the maximum energy density generated by the transmitter 22 and incident on the display screen 12. Therefore, in some implementations, the optical proximity sensor module 14 includes a microlens or microlens array 26 disposed in the path of the light beam 28 emitted by the transmitter 22. The microlens or microlens array 26 intersects the beam 28 before it is incident on the back side of the display screen 12 and causes the beam 28 to propagate slightly radially, thereby reducing the maximum energy density of the beam 30 incident on the OLED screen. Therefore, in general, the microlens or microlens array 26 generates a beam 30 that is wider than the beam 28 generated by the transmitter 22 alone (for example, a beam that is one-half and a half-width larger than the beam 28). Reducing the maximum energy density of the light beam 30 incident on the display screen 12 can reduce or eliminate screen distortion (or at least reduce or eliminate the user's perception of this distortion). In addition, in some examples, the microlens array 26 may be implemented to provide a more uniform light beam 30. In some cases, the microlens or microlens array 26 is operable to leave the microlens or microlens array The light beam 30 in the column is substantially perpendicular to the surface of the OLED display. This feature can help reduce the amount of light that can be reflected by the display screen 12 irradiating the light sensor 24, thereby reducing optical crosstalk.

3A to 3C illustrate further details of the optical proximity sensor module 14 according to certain implementations. In some cases, the microlens array 26 covers an area of ^{about 480 μm 2 directly above the emitter 22.} The different areas of the microlens array 26 may be appropriate for other implementations. FIG. 4 illustrates a specific example of a microlens array 26, which includes circular microlenses 26A arranged at a pitch d1. In some cases, the spacing d1 is equal to 95 μm, but different values may be appropriate for other implementations. FIG. 5 illustrates another example of a microlens array 26, which includes hexagonal microlenses 26B arranged at a pitch d2. In some cases, the distance d2 is equal to 95 μm, but a different value may be appropriate for other implementations.

In some embodiments, instead of or in addition to the microlens or microlens array, the means for reducing the maximum energy density includes an optical diffuser.

As further shown in FIGS. 2 and 3A to 3C, the optical proximity sensor module 14 may also include an optical element 32 (such as a lens) located above the light sensor 24 and operable to face The light sensing element of the light sensor 24 guides the incoming light (for example, the light reflected by the target object). Providing such an optical element 32 can help improve sensitivity and noise rejection.

In some implementations, as shown in the example of FIG. 6, a plurality of emitters 22 are arranged in an optical proximity sensor module 114 and arranged relative to each other so as to be scattered on the display screen 12. The resulting light spot. In this case, each of the emitters 22 can be operated to generate a lower maximum energy density, so as to reduce the density of IR or NIR light incident on the back of the display screen 12, while maintaining the total energy to achieve Satisfyingly close to the test performance. For example, in some cases, instead of applying a current of 15 mA to each emitter 22 (for example, a VCSEL light emitter), a current of 5 mA is applied. Different current values may be appropriate for other implementations. In some cases, ^{one of the maximum optical energy density of 3 mW/mm 2 is} incident on the back of the display screen 12. In some cases, each VCSEL is operated to generate a maximum energy level of about 2.0mW and preferably a maximum energy level of about 1.5mW (corresponding to a driving current of about 2mA to 3mA for some VCSELs) ) To prevent screen distortion. In addition, although the example of FIG. 6 shows three transmitters 22, other implementations may use only two transmitters or more than three transmitters. In any case, multiple emitters 22 are used to provide sufficient optical energy for proximity sensing without concentrating the light energy in the same area so as to adversely affect the pixels of the OLED screen (for example, to prevent To assist the human eye to be a visible light spot, or to reduce the distortion that might otherwise occur).

FIG. 7 illustrates an example of the technique of combining FIG. 2 and FIG. 6. Therefore, the optical proximity sensor module 214 includes a component (for example, a microlens or a microlens array 26 or a diffuser) for reducing the maximum energy density as described in conjunction with FIGS. 2 to 5, and There are multiple transmitters 22 as explained in conjunction with FIG. 6.

The design of smart phones and other host computing devices referred to in this creation may include one or more processors, one or more memories (such as RAM), and storage devices (such as a magnetic disk or flash memory) , A user interface (for example, it may include a small keyboard, a TFT LCD or OLED display screen, touch or other gesture sensors, a camera or other optical sensors, a compass sensor, a 3D magnetic Meter, a 3-axis accelerometer, a 3-axis gyroscope, one or more microphones, etc., and software commands for providing a graphical user interface), interconnects between these components (for example, a bus) And an interface used to communicate with other devices (which can be wireless (such as GSM, 3G, 4G, CDMA, WiFi, WiMax, Zigbee, or Bluetooth) and/or wired (such as through an Ethernet local area network) , A T-1 Internet connection Wait)).

The various aspects of the subject matter and functional operations described in this specification can be implemented in digital electronic circuits or computer software, firmware, or hardware containing the structures disclosed in this specification and their structural equivalents, or by Implemented in one or a combination of them. Therefore, the subject matter described in this specification can be implemented as one or more computer program products, that is, one or more computer program instruction modules encoded on a computer-readable medium for The data processing equipment executes or is used to control the operation of the data processing equipment. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter that realizes a machine-readable propagated signal, or one or a combination of them. In addition to hardware, the device may also contain code that creates an execution environment for one of the computer programs in question, for example, code that constitutes the firmware of the processor.

Any form of programming language that can include compiled language or interpretation language to write a computer program (also called a program, software, software application, script or code), and can deploy the computer program in any form , Including deployment as an independent program or deployment as a module, component, subroutine, or other units suitable for use in a computing environment. A computer program need not correspond to a file in a file system. A program can be stored in a part of a file that holds other programs or data (for example, stored in one or more scripts in a markup language document), in a single file dedicated to the program in question, Or be stored in multiple coordinated files (for example, files that store one or more modules, subprograms, or parts of code). A computer program can be deployed to be executed on one computer or on multiple computers located at one site or distributed across multiple sites and interconnected by a communication network.

The procedures and logic flows described in this manual can be executed by one or more programmable processors that execute one or more computer programs to manipulate input data and Produce output to perform the function. These programs and logic flows can also be executed by special-purpose logic circuits (for example, an FPGA (Field Programmable Gate Array) or an ASIC (Special Application Integrated Circuit)), and the device can also be implemented as the special-purpose logic Circuit.

By way of example, processors suitable for executing a computer program include both general-purpose microprocessors and special-purpose microprocessors, and any one or more processors of any kind of digital computer. Generally speaking, a processor will receive commands and data from a read-only memory or a random access memory or both. The basic components of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including by way of example: semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory) Devices); magnetic disks (for example, internal hard disks or removable disks); magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and memory can be supplemented by special-purpose logic circuits or incorporated into special-purpose logic circuits.

Although this specification contains many specific details, these specific details should not be regarded as limitations on the creation or the scope of the claim, but should be regarded as descriptions of the unique features of the specific embodiments of the creation. The specific features described in this specification in the context of individual embodiments can also be implemented in a single embodiment in combination. Conversely, various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination form. In addition, although features may be described above as functioning in certain combinations and even initially claimed to be so, one or more of the features from a claimed combination may in some cases be removed from the combination, and the claimed combination Can be aimed at a sub-combination or a sub-combination variation.

Similarly, although operations are depicted in a specific order in the drawings, this should not be understood as requiring that these operations be performed in the specific order shown or in a sequential order, or to perform All operations illustrated to achieve the desired result. In some situations, multitasking and parallel processing may be advantageous.

Several implementation options have been described. However, various modifications can be made without departing from the spirit and scope of this creation. Therefore, other implementation schemes are also within the scope of the patent application.

12: Display screen

14: Optical proximity sensor module

22: Launcher

24: light sensor

26: Micro lens array

28: beam

30: beam

32: optical components

34: printed circuit board

Claims (17)

An optical proximity sensor module configured to be placed behind a display screen of a device, the optical proximity sensor module comprising: at least one light emitter, which is operable to generate light having a wavelength , The light is transmitted through the display screen toward a target object; a light sensor, which is operable to sense the light reflected by the target object and having the wavelength; and used to reduce the light generated by the at least one light emitter One or more beams of one of the largest energy density components, wherein the component for reducing the maximum energy density of the beams is arranged between the at least one light emitter and the display screen, so as to communicate with the light The one or more beams generated by the transmitter intersect; wherein the member for reducing the maximum energy density of the one or more beams is operable to cause the beam to propagate radially so as to reduce the incidence on the display screen The maximum energy density of the beam above. Such as the module of claim 1, wherein the display screen is an OLED display screen. The module of claim 1 or 2, wherein the member for reducing the maximum energy density of the at least one light beam includes a micro lens. The module of claim 1 or 2, wherein the member for reducing the maximum energy density of the at least one light beam includes a microlens array. The module of claim 1 or 2, wherein the member for reducing the maximum energy density of the at least one light beam includes an optical diffuser. The module of claim 1 or 2, wherein a beam of the member for reducing the maximum energy density of the beam has a half beam and a half width larger than the beam emitted by the light emitter. Such as the module of claim 1 or 2, wherein the light transmitter is operable to generate infrared light or near-infrared light. Such as the module of claim 1 or 2, and it is configured to illuminate a back side of the display screen with a light energy density of ^{3mW/mm 2 or less.} An optical proximity sensor module configured to be placed behind a display screen of a device. The optical proximity sensor module includes: a plurality of light emitters, which are operable to generate infrared or near-infrared light , The infrared or near-infrared light is transmitted through the display screen toward a target object; and a light sensor operable to sense infrared or near-infrared light reflected by the target object, wherein the plurality of light emitters are Jointly operable to provide sufficient optical energy for proximity sensing, the light emitters disperse the optical energy used for proximity sensing, thereby reducing distortion of the display screen; wherein the plurality of light emitters are It is configured to illuminate a back side of the display screen with a light energy density of ^{3mW/mm 2 or less.} Such as the module of claim 9, wherein each of the light emitters is operable to generate an energy density so as to reduce a maximum energy density of light incident on a back side of the display screen, and at the same time Maintain the total energy to promote the proximity sensory performance. For example, the module of claim 9 or 10, wherein the display screen is an OLED display screen. Such as the module of claim 9 or 10, wherein the plurality of light emitters include a plurality of VCSELs, and each of the plurality of VCSELs is operated to generate an energy level of 2.0 mW or less. Such as the module of claim 9 or 10, wherein the plurality of light emitters include a plurality of VCSELs, and each of the plurality of VCSELs is operated to generate an energy level of 1.5 mW or less. Such as the module of claim 9 or 10, wherein the member for reducing the maximum energy density of the light beam is arranged between the light emitter and the display screen so that the light beam generated by the light emitter intersects . The module of claim 10, wherein the member for reducing the maximum energy density of the light beam includes a microlens array or a diffuser. An electronic device comprising a display screen and optical proximity sensor modules such as request items 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 , The optical proximity sensor module is arranged behind the display screen. Such as the device of claim 16, wherein the display screen is an OLED display screen.

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