阅读说明：本技术 光学感测模块 (Optical sensing module ) 是由 陈怡永 吴高彬 张鸿德 于 2018-11-15 设计创作，主要内容包括：本发明是一种光学感测模块,包含有一光源及一光学感测集成电路装置；其中该光源用以发射一光信号,而该光学感测集成电路装置则包含有一光学感测器及一光栅；其中该光学感测器用以感测该光信号的反射光,且该光学感测器与该光源沿着第一方向排列,该光栅则形成于该第一光学感测器的上方,且包含有多条相互平行排列的导线,且该些导线与该第一方向垂直。(The invention relates to an optical sensing module, which comprises a light source and an optical sensing integrated circuit device; wherein the light source is used for emitting a light signal, and the optical sensing integrated circuit device comprises an optical sensor and a grating; the optical sensor is used for sensing the reflected light of the optical signal, the optical sensor and the light source are arranged along a first direction, the grating is formed above the first optical sensor and comprises a plurality of conducting wires which are arranged in parallel, and the conducting wires are vertical to the first direction.)

1. An optical sensing module, comprising:

A light source; and

An optical sensing integrated circuit device, comprising:

A first optical sensor, the first optical sensor and the light source being arranged along a first direction; and

and a grating formed above the first optical sensor, wherein the grating comprises a plurality of wires arranged in parallel, and the wires are perpendicular to the first direction.

2. The optical sensing module of claim 1, wherein:

The optical sensing integrated circuit device is provided with a plurality of conductor layers above the first optical sensor; and

The grating is located on one of the conductor layers.

3. The optical sensing module of claim 1 or 2, wherein the first optical sensor is a proximity sensor for detecting the proximity of an object.

4. The optical sensing module of claim 1 or 2, wherein the first optical sensor is an infrared sensor.

5. The optical sensing module of claim 1 or 2, wherein the optical sensing integrated circuit device further comprises:

A second optical sensor, which is an ambient light sensor for sensing ambient light.

6. The optical sensing module of claim 1 or 2, wherein the light source is an infrared light emitting diode.

7. The optical sensing module of claim 1 or 2, further comprising:

and the circuit board is used for arranging the light source and the optical sensing integrated circuit device.

8. the optical sensing module of claim 7, further comprising:

A shell, set on the circuit board to cover the light source and the optical sensing integrated circuit device, wherein the shell includes:

A first opening aligned with the light source below; and

A second opening aligned with the first optical sensor of the optical sensor integrated circuit device below.

9. The optical sensing module of claim 8, wherein the housing further comprises a partition wall between the light source and the optical sensing integrated circuit device.

Technical Field

the present invention relates to an optical sensor module, and more particularly, to an optical sensor module with a grating.

background

proximity sensors (proximity sensors) and ambient light sensors are widely used in portable electronic devices, such as smart phones. Generally, the proximity sensor is disposed in the vicinity of the ambient light sensor. In order to improve the signal-to-noise ratio (SNR) of the proximity sensor, the prior art uses a geometric structure (opening) to limit the viewing angle of the proximity sensor. For example, by reducing the opening above the proximity sensor for light, noise is reduced from entering the proximity sensor. However, the prior art has at least the following disadvantages, one of which is that the geometry also limits the viewing angle of the ambient light sensor, which is detrimental to the operation of the ambient light sensor, and the allowable tolerance range is smaller and smaller as the component size is smaller, which makes the desired geometry difficult to realize.

Therefore, there is a need for an innovative optical sensing structure to effectively improve the signal-to-noise ratio of the optical sensor without the limitation of the geometric structure.

Disclosure of Invention

accordingly, the present invention is directed to an optical sensor module with a grating, so as to overcome the drawbacks of the conventional optical sensors.

The main technical means to achieve the above object is to make the optical sensing module include:

A light source; and

an optical sensing integrated circuit device, comprising:

a first optical sensor arranged along a first direction with the light source; and

and a grating formed above the first optical sensor, wherein the grating comprises a plurality of wires arranged in parallel, and the wires are perpendicular to the first direction.

The grating is formed above the first optical sensor, so that noise can be reduced from entering the first optical sensor, and the signal-to-noise ratio of the optical sensing module is improved.

Drawings

FIG. 1: an embodiment of the optical sensing module of the present invention is a cross-sectional view.

FIG. 2: the relative positions of the first optical sensor and the light source in FIG. 1 are illustrated.

FIG. 3A: the cross-sectional view of the first embodiment of the first optical sensor of the optical sensing module of the present invention is shown.

FIG. 3B: the cross-sectional view of the second embodiment of the first optical sensor of the optical sensing module of the present invention is shown.

FIG. 3C: the cross-sectional view of the third embodiment of the first optical sensor of the optical sensing module of the present invention is shown.

FIG. 4: an incident angle and refractive index profile of light entering the glass material.

FIG. 5: fig. 3A is an enlarged partial cross-sectional view.

wherein, the reference numbers:

10 optical sensing module 11 circuit board

12 first opening of housing 121

122 second opening 13 partition wall

14 glass 20 light source

30 optical sensing integrated circuit device 31 first optical sensor

311 transparent dielectric layer 32 Grating

321 conducting wire 33 second optical sensor

35 routing 40 object

Detailed Description

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Fig. 2 is a schematic diagram of the optical sensing module 10 of the present invention, wherein the optical sensing module 10 may be a part of an electronic device (not shown in fig. 1), wherein the electronic device may be, but is not limited to, a portable electronic device, such as a mobile phone, a tablet computer, or a notebook computer.

the optical sensing module 10 may include, but is not limited to, a light source 20 and an optical sensing integrated circuit device 30. The light source 20 and the optical sensing integrated circuit device 30 are disposed on a circuit board 11. The light source 20 may be an infrared light emitting diode for emitting infrared light. The optical sensor integrated circuit device 30 includes a first optical sensor 31 and a second optical sensor 33. In one embodiment, the first optical Sensor 31 is a Proximity Sensor (PS) for detecting the Proximity of an object, and the second optical Sensor 33 is an Ambient Light Sensor (ALS) for detecting Ambient Light, which may be, but is not limited to, an infrared Sensor.

Fig. 2 is a schematic diagram illustrating the relative positions of the first optical sensor 31 and the light source 20. The first optical sensor 31 and the light source 20 are arranged along the first direction X. The grating 32 is formed above the first optical sensor 31, and the grating 32 includes a plurality of conductive lines 321 arranged in parallel, wherein the conductive lines 321 are perpendicular to the first direction X.

Fig. 3A to 3C are schematic diagrams respectively illustrating partial cross-sectional views of an embodiment of the optical sensing integrated circuit device 30, the cross-sectional views being cut along the X direction shown in fig. 2. A plurality of conductive layers M1, M2 and M3 are sequentially formed over the first optical sensor 31. In one embodiment, the conductive layers M1, M2 and M3 are made of metal. M1 has a transparent dielectric layer 311 between the first optical sensor 31 and the conductive layer, which allows light to pass through. The grating 32 composed of a plurality of parallel wires 321 can be formed on one of the conductive layers M1, M2 and M3, and the plurality of wires 321 of the grating 32 are formed together in the process of manufacturing a conductive layer. For example, in the embodiment of fig. 3A, the plurality of conductive lines 321 of the grating 32 are formed by the conductive layer M1, in the embodiment of fig. 3B, the plurality of conductive lines 321 of the grating 32 are formed by the conductive layer M2, and in the embodiment of fig. 3C, the plurality of conductive lines 321 of the grating 32 are formed by the conductive layer M3. The conductive layers M1, M2 and M3 are further used to form the trace 35. The trace 35 is used for transmitting an electrical signal or a sensing signal of the first optical sensor 31. In other embodiments, there may be more or less conductive layers above the first optical sensor 31, and the invention is still applicable.

Referring to the schematic diagram provided in fig. 5, the width w, the height h and the spacing d OF the wires 321 OF the grating 32 determine a view angle FOV (field OF view) OF the first sensor 31, which can be understood as an incident angle range OF light entering the first optical sensor 31. The smaller the viewing angle FOV, the less light can enter the first optical sensor 31. Therefore, the width w, height h and spacing d of the conductive lines 321 of the grating 32 are determined according to the signal-to-noise ratio requirements of the first optical sensor 31. In the embodiment of fig. 1, the optical sensing module 10 further includes, but is not limited to, a housing 12 and a partition wall 13. The housing 12 is disposed on the circuit board 11 and covers the light source 20 and the optical sensing integrated circuit device 30. The housing 12 is formed with a first opening 121 aligned with the light source 20 therebelow so as to allow light emitted from the light source 20 to pass therethrough. The housing 12 is formed with a second opening 122 aligned with the first optical sensor 31 and the second optical sensor 33 therebelow, so as to allow light to enter the first optical sensor 31 and the second optical sensor 33. The partition wall 13 is located between the light source 20 and the optical sensing integrated circuit device 30 for separating the light source 20 and the optical sensing integrated circuit device 30. In the embodiment of fig. 1, a partition wall 13 extends downward from the inner top surface of the housing 12 and abuts against the circuit board 11.

The glass 14 on the housing 12 is part of the electronic device. A portion of the light signal LS emitted upward by the light source 20 passes through the glass 14 and is reflected by an object 40 (e.g. a finger) located outside the electronic device, so as to generate a first reflected light RS1 toward the first optical sensor 31. Another part of the light signal LS emitted upward from the light source 20 is internally reflected by the glass 102 a plurality of times to generate a second reflected light RS2 to the first optical sensor 31. for the first optical sensor 31, the first reflected light RS1 is used to detect the approach of the object 40, and the second reflected light RS2 is unwanted noise.

Referring to fig. 4, which is a graph showing the characteristics of the incident angle and the refractive index after a light beam enters the glass 14, it can be seen that the ratio of the S-polarized light (S) Sp in the second reflected light RS2 is greater than the ratio of the P-polarized light (P-polarized) Pp, so that if the S-polarized light in the second reflected light is reduced to enter the first optical sensor 31, the signal-to-noise ratio can be improved.

the grating 32 formed above the first optical sensor 31 acts as a Polarizer (Polarizer) and can reflect the S-polarized light component of the second reflected light RS2, so that the energy of the second reflected light RS2 entering the first optical sensor 31 is greatly reduced, thereby achieving the effect of reducing noise and increasing the signal-to-noise ratio of the first optical sensor 31.

On the other hand, as can be understood from the view angle FOV of fig. 5, the grating 32 limits the range of incident angles that can enter the first optical sensor 31, and since the incident angle of the second reflected light RS2 (noise) to the first optical sensor 31 is large, most of the second reflected light RS2 will not enter the first optical sensor 31, and the incident angle of the first reflected light RS1 to the first optical sensor 31 is very small, the first reflected light RS1 can be received by the first optical sensor 31 through the grating 32. In other words, the physical structure of the grating 32 can limit the viewing angle FOV of the first optical sensor 31, and reduce the noise (the second reflected light RS2) entering the first optical sensor 31, thereby increasing the signal-to-noise ratio. Furthermore, the grating 32 has the function of limiting the FOV of the first optical sensor 31, so that the prior art using an opening to limit the FOV of the first optical sensor 31 can be replaced. The precision required for forming the second opening 122 in the housing 12 can be reduced, which is beneficial to the miniaturization of the whole optical sensing module 10.

The above description is only an embodiment of the present invention, and is not intended to limit the present invention in any way, and in other embodiments, it is also possible to omit the second optical sensor 33. Although the present invention has been described with reference to the above embodiments, it should be understood that the invention is not limited to the above embodiments, and those skilled in the art can make various changes and modifications without departing from the scope of the invention.