WO2021051710A1

WO2021051710A1 - Fingerprint sensing module and electronic apparatus

Info

Publication number: WO2021051710A1
Application number: PCT/CN2019/129829
Authority: WO
Inventors: 范成至; 张添祥; 周正三
Original assignee: 神盾股份有限公司
Priority date: 2019-09-22
Filing date: 2019-12-30
Publication date: 2021-03-25
Also published as: CN211554956U; CN110969151A; TW202113664A; TWM594198U

Abstract

A fingerprint sensing module (200), comprising an image sensor (220), a collimator (230), a filter (240) and a light-shielding structure (250). The collimator (230) is disposed on the image sensor (220), and the filter (240) is disposed between the image sensor (220) and the collimator (230). The light-shielding structure (250) is disposed at the periphery of the filter (240) in order to block stray light from entering into the image sensor (220). Also proposed is an electronic apparatus (100).

Description

Fingerprint sensing module and electronic device

Technical field

The invention relates to a sensing module, and in particular to a fingerprint sensing module and an electronic device.

Background technique

With the development of portable electronic devices (such as smart phones or tablet computers) toward large screen-to-body ratios or full screens, the traditional capacitive fingerprint sensor module located next to the screen can no longer be placed on the front of the electronic device. Therefore, a capacitive fingerprint sensor module arranged on the side or back of the electronic device is adopted. However, the capacitive fingerprint sensing module placed on the side or the back has its inconvenience in use. Therefore, an optical fingerprint sensing module placed under the screen has recently been developed.

Since the fingerprint sensing module is placed under the screen, the thinner the thickness of the fingerprint sensing module, the better to avoid affecting the thickness of the electronic device. On the other hand, when the optical fingerprint sensing solution uses the visible light emitted by the screen to illuminate the fingerprint, and the image sensor below the screen is used to sense the visible light reflected by the fingerprint, in order to avoid sunlight affecting the accuracy of fingerprint recognition, the optical fingerprint is generally used. An infrared cut-off filter is added above the fingerprint sensor module to solve the problem of outdoor use under strong light. However, such a design makes it difficult to reduce the thickness of the fingerprint sensing module, which in turn causes the electronic device to be too thick.

Another solution is to integrate the infrared light cut filter directly on the fingerprint sensor chip and place it between the image sensor and the collimator, which can reduce the thickness of the glass substrate required for the external infrared light cut filter. In turn, the overall module thickness is reduced. However, since the area of the infrared cut filter integrated on the chip does not exceed the area of the image sensor, this design allows stray light (such as infrared light or visible light) to enter the image sensor from the edge of the image sensor, thereby causing noise.

Summary of the invention

The invention is directed to a fingerprint sensing module and an electronic device, which has a good sensing effect and can have a thinner thickness.

An embodiment of the present invention provides a fingerprint sensing module, including an image sensor, a collimator, a filter, and a light-shielding structure. The collimator is arranged on the image sensor, and the filter is arranged between the image sensor and the collimator. The light-shielding structure is arranged around the filter to block stray light from entering the image sensor.

An embodiment of the present invention provides an electronic device including a display panel and the aforementioned fingerprint sensing module. The fingerprint sensing module is disposed under the display panel to sense the light emitted by the display panel, reflected by a finger placed on the display panel and penetrating the display panel.

In an embodiment of the present invention, the filter is an infrared cut filter.

In an embodiment of the present invention, the light-shielding structure is a light-shielding glue covering the side surfaces of the image sensor, the filter and the collimator.

In an embodiment of the present invention, the shading structure is a shading tape attached to the edge of the upper surface of the collimator.

In an embodiment of the present invention, the fingerprint sensing module further includes a flexible printed circuit board, which is disposed on the bottom plate and located around the image sensor.

In an embodiment of the present invention, the light-shielding structure is a light-shielding glue, which covers the side surfaces of the image sensor, the filter and the collimator, and is filled in the image sensor and the filter. In the gap between the entirety of the sheet and the collimator and the entirety of the flexible printed circuit board and the foam on it.

In an embodiment of the present invention, the light-shielding structure is a light-shielding tape attached to the edge of the upper surface of the collimator and covers the image sensor, the filter and the collimator The gap between the entirety of the flexible printed circuit board and the entirety of the foam on the flexible printed circuit board.

In an embodiment of the present invention, the collimator is an optical fiber plate, a lens array or a lens.

In the fingerprint sensing module and the electronic device of the embodiment of the present invention, the filter is disposed between the image sensor and the collimator, and the light shielding structure is disposed around the filter to prevent stray light from entering the image sensor. Therefore, the fingerprint sensing module and the electronic device can have a good fingerprint sensing effect and can have a thinner thickness.

Description of the drawings

The accompanying drawings are included for further understanding of the present invention, and the accompanying drawings are incorporated into this specification and constitute a part of this specification. The drawings illustrate embodiments of the present invention, and together with the description serve to explain the principles of the present invention.

FIG. 1 is a schematic cross-sectional view of an electronic device according to an embodiment of the invention;

2 is a schematic cross-sectional view of an electronic device according to another embodiment of the invention.

Attached icon number description

50: Finger

100, 100a: electronic device

110: display panel

112: Light

120: Foam

200, 200a: fingerprint sensor module

210: bottom plate

220: Image sensor

230: collimator

232: Upper surface

240: filter

250, 250a: shading structure

260: Flexible printed circuit board

270: Bonding line

280: Chip attach film

G: gap

detailed description

Reference will now be made in detail to the exemplary embodiments of the present invention, and examples of the exemplary embodiments are illustrated in the accompanying drawings. Whenever possible, the same component symbols are used in the drawings and descriptions to indicate the same or similar parts.

FIG. 1 is a schematic cross-sectional view of an electronic device according to an embodiment of the invention. Please refer to FIG. 1, the electronic device 100 of this embodiment includes a display panel 110 and a fingerprint sensing module 200. The display panel 110 is, for example, an organic light-emitting device (OLED) display panel. However, in other embodiments, the display panel 110 may also be a liquid crystal display panel or other suitable display panels. The fingerprint sensing module 200 is disposed under the display panel 110 to sense the light 112 emitted by the display panel 110 and reflected by the finger 50 placed on the display panel 110 and penetrating the display panel 110. In this embodiment, the display panel 110 is, for example, a transparent display panel. However, in other embodiments, the display panel 110 may also be a display panel having a light-transmitting opening in the area above the fingerprint sensing module 200. The electronic device 100 is, for example, a mobile phone, a tablet computer, a notebook computer, or other appropriate electronic devices.

The fingerprint sensing module 200 includes a bottom plate 210, an image sensor 220, a collimator 230, a filter 240, and a light shielding structure 250. The image sensor 220 is disposed on the bottom plate 210, the collimator 230 is disposed on the image sensor 220, and the filter 240 is disposed between the image sensor 220 and the collimator 230. In this embodiment, the bottom plate 210 is a rigid metal sheet, such as an iron sheet. The image sensor 220 is, for example, a complementary metal oxide semiconductor (CMOS) sensor or a charge coupled device (CCD). The collimator 230 is, for example, a fiber optic plate, a microlens array, or a collimating structure formed by other methods, which can collimate and transmit the light 112 from the finger 50 to be imaged on the image sensor 220. Alternatively, the collimator 230 may also be any other device capable of collimating and transmitting the light 112 from the finger 50 to be imaged on the image sensor 220. The filter 240 is, for example, an infrared cut filter. However, in other embodiments, the filter 240 may also be a filter for filtering other visible light wavebands or invisible light wavebands.

The light shielding structure 250 is disposed around the filter 240 and the image sensor 220 to block stray light from entering the image sensor 220. In this embodiment, the light-shielding structure 250 is a light-shielding glue, for example, a light-absorbing glue (such as a black glue). In this embodiment, the fingerprint sensing module 200 further includes a flexible printed circuit (FPC) 260, which is disposed on the bottom plate 210 and located around the image sensor 220. The image sensor 220 is electrically connected to the flexible printed circuit board 260 through a bonding wire 270. In one embodiment, the light-shielding structure 250 is filled in the gap G between the image sensor 220 and the flexible printed circuit board 260 to cover the side surfaces of the image sensor 220, the filter 240 and the collimator 230 to block stray light Enter from the side of the image sensor 220. In one embodiment, the light-shielding structure 250 is filled in the gap G between the entirety of the image sensor 220, the filter 240, and the collimator 230, and the entirety of the flexible printed circuit board 260 and the foam 120 thereon. . In addition, in an embodiment, the light shielding structure 250 may cover the bonding wire 270.

In the fingerprint sensing module 200 and the electronic device 100 of this embodiment, the filter 240 is disposed between the image sensor 220 and the collimator 230. Therefore, the filter 240 can be directly formed on the image sensor 220 to make fingerprints sense. The measurement module 200 may have a thinner thickness, thereby reducing the thickness of the electronic device 100. In addition, in this embodiment, since stray light is blocked by the light shielding structure 250 and cannot enter the image sensor 220, the fingerprint sensor module 200 and the electronic device 100 equipped with the fingerprint sensor module 200 can obtain good quality Fingerprint images, without the edge of the fingerprint image being overexposed due to stray light.

In this embodiment, the image sensor 220 can be attached to the bottom plate 210 by a die attach film 280. In addition, the electronic device 100 may have a foam 120 disposed between the flexible printed circuit board 260 and the display panel 110.

2 is a schematic cross-sectional view of an electronic device according to another embodiment of the invention. Please refer to FIG. 2. The electronic device 100a of this embodiment is similar to the electronic device 100 of FIG. 1, and the main differences between the two are as follows. In the fingerprint sensing module 200a of the electronic device 100a of this embodiment, the light-shielding structure 250a is a light-shielding tape, such as a light-absorbing tape (such as a black tape), which is attached to the edge of the upper surface 232 of the collimator 230, and The gap G between the image sensor 220 and the flexible printed circuit board 260 or the foam 120 is covered. In one embodiment, the light shielding structure 250a covers the gap G between the entirety of the image sensor 220, the filter 240, and the collimator 230, and the entirety of the flexible printed circuit board 260 and the foam 120 thereon.

The light-shielding

structures

250 and 250a of the above embodiments may use materials that can shield visible light, infrared light, and ultraviolet light, or materials that can absorb visible light, infrared light, and ultraviolet light. In addition, the light-shielding

structures

250 and 250a of the above embodiments may be rectangular frames, and the opening in the middle of the rectangular frames exposes the sensing area (ie, the area used for light-sensing) of the image sensor 220, but the present invention is not limited to this.

In summary, in the fingerprint sensing module and the electronic device of the embodiment of the present invention, the filter is disposed between the image sensor and the collimator, and the light shielding structure is disposed around the filter to block stray light Enter the image sensor. Therefore, the fingerprint sensing module and the electronic device can have a good fingerprint sensing effect, and can therefore have a thinner thickness.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions recorded in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention. range.

Claims

A fingerprint sensing module, characterized in that it comprises:

Image Sensor;

The collimator is configured on the image sensor;

The filter is disposed between the image sensor and the collimator; and

The light-shielding structure is arranged around the filter to block stray light from entering the image sensor.
The fingerprint sensing module according to claim 1, wherein the filter is an infrared light cut filter.
The fingerprint sensing module according to claim 1, wherein the shading structure is a shading glue covering the side surfaces of the image sensor, the filter and the collimator.
The fingerprint sensing module according to claim 1, wherein the shading structure is a shading tape attached to the edge of the upper surface of the collimator.
The fingerprint sensing module according to claim 1, further comprising a flexible printed circuit board, which is disposed on the bottom plate and located around the image sensor.
5. The fingerprint sensor module according to claim 5, wherein the shading structure is a shading glue, covering the side surfaces of the image sensor, the filter and the collimator, and filling the image sensor, In the gap between the entirety of the filter and the collimator and the entirety of the flexible printed circuit board and the foam on it.
The fingerprint sensing module according to claim 5, wherein the shading structure is a shading tape, attached to the edge of the upper surface of the collimator, and covering the image sensor, the filter and all The gap between the whole of the collimator and the whole of the flexible printed circuit board and the foam on it.
The fingerprint sensing module according to claim 1, wherein the collimator is an optical fiber plate, a lens array or a lens.
An electronic device, characterized in that it comprises:

Display panel; and

The fingerprint sensing module is configured under the display panel to sense the light emitted by the display panel, reflected by a finger placed on the display panel and penetrating the display panel. The fingerprint sensing The modules include:

Image Sensor;

The collimator is configured on the image sensor;

The filter is disposed between the image sensor and the collimator; and

The light-shielding structure is arranged around the filter to block stray light from entering the image sensor.
9. The electronic device according to claim 9, wherein the filter is an infrared cut filter.
9. The electronic device according to claim 9, wherein the light-shielding structure is a light-shielding glue covering the side surfaces of the image sensor, the filter and the collimator.
9. The electronic device according to claim 9, wherein the light-shielding structure is a light-shielding tape attached to the edge of the upper surface of the collimator.
9. The electronic device according to claim 9, wherein the fingerprint sensing module further comprises a flexible printed circuit board, which is disposed on the bottom plate and located around the image sensor.
The electronic device according to claim 13, wherein the light-shielding structure is a light-shielding glue covering the side surfaces of the image sensor, the filter and the collimator, and is filled in the image sensor and the collimator. In the gap between the entirety of the filter and the collimator and the entirety of the flexible printed circuit board and the foam on it.
The electronic device according to claim 13, wherein the light-shielding structure is a light-shielding tape attached to the edge of the upper surface of the collimator and covers the image sensor, the filter and the collimator. The gap between the whole of the straightener and the whole of the flexible printed circuit board and the foam on it.
The electronic device according to claim 9, wherein the collimator is a fiber board, a lens array, or a lens.