TW202335277A - Biological feature sensor module - Google Patents

Abstract

The biological feature sensor module includes multiple pixels, and each of the pixels includes a color filter layer, an Infrared-cut layer and an optical sensor. The infrared-cut layer is located below the color filter layer. The optical sensor is located below the infrared-cut layer. The color filter layer of one of the pixels includes a first filter layer and a second filter layer having different colors. The first filter layer overlaps the second filter layer along an orthogonal projection direction.

Description

Biometric sensing module

This disclosure is about a biometric sensing module.

Most current electronic devices have identity authentication mechanisms, and the use of biometrics for identity recognition has been a trend in recent years. A common authentication method is fingerprint recognition, because fingerprint recognition is easy to integrate into electronic devices.

However, the green light band of the infrared light cutoff layer in the current biometric sensing module has a high transmittance, and the absorption spectrum of the sensing module is mostly distributed in the blue-green light band. As a result, the infrared light blocking layer will cause the signal received by the photosensitive element to decrease. In addition, the infrared light cut-off layer cannot be used with the filter layer in the red light band, resulting in a decrease in the anti-counterfeiting function of the biometric sensing module.

In view of this, how to provide a biometric sensing module that can solve the above problems is still a research and development goal in this field.

One technical aspect of this disclosure is a biometric sensing module.

In one embodiment, the biometric sensing module includes a plurality of pixels, where each pixel includes a light-splitting material layer, an infrared light-cutting layer and a photosensitive element. The infrared light cutoff layer is below the spectroscopic material layer. The photosensitive element is located under the infrared light cutoff layer. The light-splitting material layer of one of the plurality of pixels includes a first filter layer and a second filter layer having different colors, and the first filter layer and the second filter layer overlap in the vertical projection direction.

In one embodiment, the first filter layer is a blue filter layer, and the second filter layer is a green filter layer.

In one embodiment, the transmittance of the spectroscopic material layer in a wavelength band above 590 nanometers is less than 50%.

In one embodiment, the transmittance of the infrared light cutoff layer in a wavelength band above 570 nanometers is less than 10%.

In one embodiment, the light splitting material layer of one of the plurality of pixels further includes a green filter layer, and the green filter layer has a transmittance greater than 50% in a wavelength range of 495 nanometers to 590 nanometers.

In one embodiment, the light splitting material layer of one of the plurality of pixels further includes a blue filter layer, and the blue filter layer has a transmittance greater than 50 in a wavelength range of 400 nanometers to 495 nanometers. %.

In one embodiment, the biometric sensing module further includes a first light-shielding layer located between the infrared light cutoff layer and the photosensitive element, and the first light-shielding layer has a plurality of openings.

In one embodiment, the biometric sensing module further includes a second light-shielding layer located between the first light-shielding layer and the infrared light-cutting layer or between the first light-shielding layer and the photosensitive element.

In one embodiment, the infrared light cutoff layer has a transmittance greater than 20% in a wavelength range of 400 nanometers to 570 nanometers.

In one embodiment, the infrared light cutoff layer has a transmittance greater than 50% in a wavelength range of 420 nanometers to 550 nanometers.

In the above embodiments, by combining the light-splitting material layer and the infrared light cut-off layer with a specific transmittance distribution, the biometric sensing module of the present disclosure can simultaneously have the anti-counterfeiting function of filtering ambient light and utilizing the light-splitting material layer to split light. .

A plurality of embodiments of the present invention will be disclosed in the drawings below. For clarity of explanation, many practical details will be explained in the following description. However, it will be understood that these practical details should not limit the invention. That is to say, in some embodiments of the present invention, these practical details are not necessary. In addition, for the sake of simplifying the drawings, some commonly used structures and components will be illustrated in a simple schematic manner in the drawings. Also, the thicknesses of layers and regions in the drawings may be exaggerated for clarity, and like reference numbers refer to the same elements in the description of the drawings.

Figure 1 is a side view of a biometric identification device 10 according to an embodiment of the present disclosure. The biometric identification device 10 includes a biometric sensing module 100 and a biometric sensing module of the electronic device 200 . The biometric sensing module 100 is an under-screen optical sensing module. The biometric sensing module 100 is located in the biometric identification area 210 of the electronic device 200 . The electronic device 200 is an organic light-emitting diode display device, but the disclosure is not limited thereto. When the finger 300 presses the biometric recognition area 210, the light is reflected by the finger 300 and then enters the biometric sensing module 100.

The biometric sensing module 100 includes an anti-counterfeiting area 1002 . In this embodiment, the anti-counterfeiting areas 1002 are separated from each other, but the present disclosure is not limited to this. In other embodiments, the anti-counterfeiting area 1002 may span the entire biometric identification area 210 .

Figure 2 is a top view of the anti-counterfeiting area 1002 in Figure 1 . Each anti-counterfeiting area 1002 has a pixel array. In this embodiment, a 9x9 pixel array is taken as an example. Figure 3 is a cross-sectional view along line 3-3 in Figure 2. Refer to Figure 3. The electronic device 200 includes a cover 230 and a display panel 220 . The biometric sensing module 100 includes a spectroscopic material layer 110, an infrared light blocking layer 120, a first light shielding layer 130, a second light shielding layer 140 and a photosensitive element 150. The spectroscopic material layer 110 is located above the infrared light blocking layer 120, but the present disclosure is not limited thereto. The photosensitive element 150 is located below the first light-shielding layer 130 and the second light-shielding layer 140 . Each pixel of the anti-counterfeiting area 1002 includes a photosensitive element 150 . The biometric sensing module 100 includes a flat layer 112 covering the spectroscopic material layer 110 to make the surface of the spectroscopic material layer 110 flat and protect the color of the spectroscopic material layer 110 . The first light-shielding layer 130 and the second light-shielding layer 140 are located between the infrared light blocking layer 120 and the photosensitive element 150 . The first light-shielding layer 130 includes a plurality of openings 132, wherein each pixel includes at least one opening 132. In this embodiment, the second light-shielding layer 140 has a plurality of openings 142 that are the same as the openings 132, but the disclosure is not limited thereto.

The biometric sensing module 100 includes a dielectric layer 144 located between the first light-shielding layer 130 and the second light-shielding layer 140 . The dielectric layer 144 is transparent. The second light-shielding layer 140 can be selectively disposed above the light-splitting material layer 110 and is not limited to the position in this embodiment.

Refer to Figure 3. The biometric sensing module 100 also includes a microlens array 160 and a spacer layer 170 . The microlens array 160 is located above the first light-shielding layer 130 , and the spacer layer 170 is located between the infrared light blocking layer 120 and the microlens array 160 . The microlens array 160 includes a plurality of microlenses 162 , and each microlens 162 corresponds to a photosensitive element 150 . The spacer layer 170 is composed of a plurality of spacer pillars 172 . The biometric sensing module 100 also includes a glass substrate 180 located above the spectroscopic material layer 110 and a glass substrate 182 located below the photosensitive element 150 . The infrared light cutoff layer 120, the first light shielding layer 130, the second light shielding layer 140, the microlens array 160 and the spacer layer 170 cover the entire anti-counterfeiting area 1002.

Refer to Figure 3. In this embodiment, the biometric sensing module 100 is composed of an upper plate 100A and a lower plate 100B. The upper plate 100A is a light splitting structure, which is composed of a glass substrate 180, a light splitting material layer 110, an infrared light cutoff layer 120 and a spacer layer 170, and is used to split the light reflected by the finger 300. The lower plate 100B is a collimating structure, which is composed of a microlens array 160, a first light-shielding layer 130, a second light-shielding layer 140, a photosensitive element 150 and a glass substrate 182 to collimate the split light. In other embodiments, the structure for splitting light and the structure for collimating light in the biometric sensing module can be integrated.

Refer to Figure 2. The anti-counterfeiting area 1002 includes a red pixel 1004R, a blue pixel 1004B, a green pixel 1004G and a basic pixel 1004I. The dichroic material layer 110 in the red pixel 10042R is a red filter layer 110R, the dichroic material layer 110 in the blue pixel 1004B is a blue filter layer 110B, and the dichroic material layer 110 in the green pixel 1004G is a green filter. Layer 110G. The basic pixel 1004I does not have the above-mentioned filter layer, but is filled with a flat layer 112 (see Figure 3). In other words, in the viewing angle of FIG. 2 , the infrared light blocking layer 120 in the basic pixel 1004I is exposed from the spectroscopic material layer 110 .

The arrangement and distribution density of the red pixels 1004R, the blue pixels 1004B, and the green pixels 1004G shown in Figure 2 are only examples, and the present disclosure is not limited thereto. In this embodiment, each 3x3 pixel array includes a red pixel 1004R, a blue pixel 1004B and a green pixel 1004G. In other words, the biometric sensing module 100b in this embodiment uses three spectral bands to perform the anti-counterfeiting function. In other embodiments, it suffices as long as each 3x3 pixel array includes at least one filter layer with more than one color. It should be understood that in Figure 2, the red filter layer 110R, the blue filter layer 110B and the green filter layer 110G are exemplarily shown to cover the entire red pixel 1004R, the green pixel 1004G and the blue pixel respectively. 1004B, but this disclosure is not limited to this.

Figure 4 is a graph showing the relationship between transmittance and wavelength of a filter layer according to an embodiment of the present disclosure. As shown in the curve S1, the transmittance of the blue filter layer 110B in the wavelength range of 400 nanometers to 495 nanometers is greater than 50%, and the wavelength of 450 nanometers has the highest transmittance, which is about 85%. As shown in the curve S2, the green filter layer 110G has a transmittance greater than 50% in the wavelength range of 495 nanometers to 590 nanometers, with the highest transmittance filtering at a wavelength of 540 nanometers, which is about 90%. As shown in curve S3, the red filter layer 110R has a transmittance of greater than 50% in a wavelength band greater than 590 nanometers, and has the highest transmittance of about 95% at a wavelength of about 630 nanometers. The biometric sensing module 100 uses filter layers of different colors to obtain the spectral spectrum of the light reflected by the finger 300 to identify the authenticity of the fingerprint.

Figure 5 is a graph showing the relationship between transmittance and wavelength of the infrared light blocking layer 120 according to an embodiment of the present disclosure. The transmittance of the infrared light cutoff layer 120 in the range of wavelengths greater than 400 nanometers and less than 590 nanometers is greater than 50%, which is beneficial to the penetration of blue light and green light. In addition, the transmittance in the wavelength range of 440 nm to 560 nm is greater than 90%. In other words, almost all the light corresponding to the wavelength band with the highest transmittance of the blue filter layer 110B (approximately a wavelength of 450 nanometers) and the wavelength band with the highest transmittance of the green filter layer 110G (approximately a wavelength of 540 nanometers) can pass through. The infrared light cutoff layer 120 can avoid filtering out the light after penetrating the blue filter layer 110B and the green filter layer 110G.

The transmittance of the infrared light cutoff layer 120 in the wavelength range of greater than or equal to 590 nanometers and less than or equal to 630 nanometers is greater than 10% and less than 60%. The transmittance of the infrared light cutoff layer 120 in the wavelength band above 630 nanometers (eg, 630 nanometers to 700 nanometers) is greater than 5% and less than 15%, and the average transmittance is about 10%. In this way, the wavelength band corresponding to the red filter layer 110R (ie, 590 nanometers to 630 nanometers) still has a transmittance greater than 10%, which can avoid filtering out the light that penetrates the red filter layer 110R. In the wavelength band that easily penetrates the finger 300 and causes overexposure (ie, above 630 nanometers), the penetration rate is reduced to about 10%, thereby achieving the effect of filtering ambient light.

Based on the above, it can be seen that by combining the light-splitting material layer 110 and the infrared light cut-off layer 120 with a specific transmittance distribution, the biometric sensing module 100 of the present disclosure can simultaneously filter ambient light and use the light-splitting material layer 110 to split light. Anti-counterfeiting function.

Figure 6 is a top view of the first light-shielding layer 130 in the framed range A in Figure 2. In this embodiment, the second light-shielding layer 140 may have the same opening distribution as the first light-shielding layer 130 . The following only uses the first light-shielding layer 130 as an example.

As shown in FIG. 6 , the light-shielding area 130G of the first light-shielding layer 130 in the green pixel 1004G has one opening 132 , and the light-shielding area 130B of the first light-shielding layer 130 in the blue pixel 1004B has two openings. holes 132, and the light-shielding area 130R of the first light-shielding layer 130 in the red pixel 1004R has eight openings 132. In other words, referring to FIGS. 2 and 6 simultaneously, the number of openings 132 overlapping with the red filter layer 110R is greater than the number of openings 132 overlapping with the blue filter layer 110B. The number of overlapping openings 132 is greater than the number of overlapping openings 132 with the green filter layer 110G.

It can be seen from Figures 4 and 5 that relatively less light passes through the red filter layer 110R. Therefore, by increasing the number of openings 132 of the first light-shielding layer 130 located in the red pixel 1004R, the intensity distribution among the red light, blue light and green light received by the photosensitive element 150 can be balanced.

As shown in Figure 5, in this embodiment, it can be known from the calculation of the integrated area size of transmittance and wavelength that the transmittance distribution of the green filter layer 110G is slightly larger than the transmittance of the blue filter layer 110B. Therefore, as shown in FIG. 6 , the number of openings 132 of the first light-shielding layer 130 in the blue pixel 1004B is also greater than the number of the openings 132 of the first light-shielding layer 130 in the green pixel 1004G. In some embodiments, the number of openings 132 of the first light-shielding layer 130 in the green filter layer 110G and the blue filter layer 110B may be the same.

In this embodiment, the light-shielding area 130I of the first light-shielding layer 130 in the basic pixel 1004I has nine openings 132, but the disclosure is not limited thereto. Persons in the art can adjust the number of openings 132 in the basic pixel 1004I according to actual needs.

It should be understood that the above distribution of the number and size of openings is based on the premise that the opening sizes are the same. The relationship between the number and size of the openings 132 of the first light-shielding layer 130 is also equivalent to the relationship between the total area of the openings 132 of the first light-shielding layer 130 . In other words, the present disclosure is not limited to the aspect where the sizes of the openings 132 are all the same.

As shown in Figure 6, the total area of the openings 132 in the red pixel 1004R is greater than the total area of the openings 132 in the blue pixel 1004B, and the total area of the openings 132 in the red pixel 1004R is also greater than that of the green pixel. The total area of openings 132 in 1004G. Similarly, the total area of the openings 132 in the blue pixel 1004B in this embodiment is larger than the total area of the openings 132 in the green pixel 1004G.

Through the above design, the intensity distribution among the red light, blue light and green light received by the photosensitive element 150 can be balanced. In one embodiment, the total area of the openings 132 of the first light-shielding layer 130 in the red pixel 1004R occupies approximately 80% of the area of the first light-shielding layer 130 in the red pixel 1004R, and the total area of the openings 132 in the blue pixel 1004B The total area of the openings 132 of a light-shielding layer 130 occupies approximately 20% of the area of the first light-shielding layer 130 in the blue pixel 1004B, while the total area of the openings 132 of the first light-shielding layer 130 in the green pixel 1004G occupies approximately 10% of the area of the first light-shielding layer 130 in the green pixel 1004G. The above-mentioned total area ratio of the openings 132 is only an example and is not intended to limit the present disclosure. Specifically, taking ambient light and anti-counterfeiting functions into consideration, it is sufficient as long as the opening 132 of the first light-shielding layer 130 in the red pixel 1004R does not cause overexposure of the fingerprint.

Figure 7 is a partial cross-sectional view of a biometric identification device 10a according to another embodiment of the present disclosure. The biometric sensing module 100a is roughly the same as the biometric sensing module 100 shown in Figure 3. The difference is that the spectroscopic material layer 110 and the infrared light cutoff layer 120 of the biometric sensing module 100a are located in the first between the light-shielding layer 130 and the second light-shielding layer 140 , and the microlens array 160 is located above the second light-shielding layer 140 . The first light-shielding layer 130 in this embodiment also has the distribution of openings 132 as shown in Figure 6. Therefore, the biometric sensing module 100a and the biometric sensing module 100 have the same technical effect, which will not be described again. .

Figure 8 is a top view of the anti-counterfeiting area 1002a of the biometric sensing module according to another embodiment of the present disclosure. Figure 9 is a cross-sectional view along line 9-9 in Figure 8. Refer also to Figures 8 and 9. The biometric sensing module 100b is substantially the same as the biometric sensing module 100 shown in FIG. 3, except that the biometric sensing module 100b has a reference pixel 1004N but not a red pixel 1004R. The dichroic material layer 110a only includes a blue filter layer 110B and a green filter layer 110G. The transmittance of the dichroic material layer 110a in the wavelength band corresponding to red light is less than 50%. In other words, the transmittance of the spectroscopic material layer 110a in the wavelength band greater than 590 nanometers is less than 50%. It can be seen from this that the biometric sensing module 100b in this embodiment uses two spectral bands to perform anti-counterfeiting functions.

The filter layer 110N in the reference pixel 1004N is composed of a blue filter layer 110B and a green filter layer 110G stacked in the vertical direction Z. In this way, the light entering the reference pixel 1004N is sequentially filtered by the blue filter layer 110B, the green filter layer 110G and the infrared light blocking layer 120a. In other words, light cannot pass through the filter layer 110N in the reference pixel 1004N. Therefore, the signal received by the photosensitive element 150 located in the reference pixel 1004N represents background noise that does not come from illumination. The signals of the anti-counterfeiting area 1002 and the normal sensing area (basic pixel 1004I, blue pixel 1004B and green pixel 1004G) can deduct this background noise to achieve the correction effect.

The arrangement of the reference pixel 1004N, the blue pixel 1004B and the green pixel 1004G shown in Figure 9 is only an example, and the present disclosure is not limited thereto. The stacking position of the blue filter layer 110B and the green filter layer 110G in the filter layer 110N in the vertical direction Z is also not limited, as long as the light reflected by the finger 300 does not enter the photosensitive element 150 of the reference pixel 1004N. .

Figure 10 is a graph showing the relationship between transmittance and wavelength of an infrared light blocking layer according to another embodiment of the present disclosure. The infrared light cutoff layer shown in Figure 10 can be applied to the biometric sensing module 100b in Figure 8 . As shown in Figure 10, when the biometric sensing module 100b does not have the red pixel 1004R, the transmittance of the infrared light cutoff layer 120a in the wavelength band above 570 nanometers is less than 10%. In other words, the cutoff band of the infrared light cutoff layer 120a is approximately 570 nanometers. The transmittance of the infrared light cutoff layer 120a in the wavelength range of 400 nanometers to 570 nanometers is greater than 20%, and the transmittance in the wavelength range of 420 nanometers to 550 nanometers is greater than 50%. In this way, the effect of filtering ambient light can be further optimized, and at the same time it has the technical effects of anti-counterfeiting and noise correction.

In summary, by combining the filter layer and the infrared light cut-off layer with a specific transmittance distribution, the biometric sensing module of the present disclosure can simultaneously filter ambient light and use the light-splitting material layer to split the light. Anti-counterfeiting function. In addition, by adjusting the number of openings in the first light-shielding layer according to the spectral wavelength band, the intensity distribution between the light of different wavelength bands received by the photosensitive element can be balanced. In other embodiments, by removing the red filter layer and using it as a reference pixel, the effect of noise reduction can be achieved. In addition, the cutoff band of the infrared light cutoff layer can be reduced to further optimize the effect of filtering ambient light.

Although the disclosure has been disclosed in the above embodiments, it is not intended to limit the disclosure. Anyone skilled in the art can make various changes and modifications without departing from the spirit and scope of the disclosure. Therefore, the protection of the disclosure The scope shall be determined by the appended patent application scope.

10,10a: Biometric identification device 100, 100a, 100b: biometric sensing module 100A: upper board 100B:Lower plate 1002,1002a: Anti-counterfeiting area 1004R: red pixel 1004G: Green pixel 1004B: blue pixel 1004N: Reference pixel 1004I: Basic pixel 110,110a: Spectroscopic material layer 110R: red filter layer 110G: Green filter layer 110B: blue filter layer 110N: Filter layer 112: Flat layer 120,120a: Infrared light cut-off layer 130: First light shielding layer 130G, 130B, 130R, 130I: light shielding area 132,142: opening 140:Second light shielding layer 144:Dielectric layer 150: Photosensitive element 160:Microlens array 162:Microlens 170: Spacer layer 172: Spacer column 180,182:Glass substrate 200:Electronic devices 210:Biometric identification area 220:Display panel 230:Cover 300:finger Z: vertical direction A: Frame selection range S1, S2, S3: Curve 3-3,9-9: Line segment

Figure 1 is a side view of a biometric identification device according to an embodiment of the present disclosure. Figure 2 is a top view of the anti-counterfeiting area in Figure 1. Figure 3 is a cross-sectional view along line 3-3 in Figure 2. Figure 4 is a graph showing the relationship between transmittance and wavelength of a filter layer according to an embodiment of the present disclosure. Figure 5 is a graph showing the relationship between transmittance and wavelength of an infrared light blocking layer according to an embodiment of the present disclosure. Figure 6 is a top view of the first light-shielding layer in the framed area in Figure 2. Figure 7 is a partial cross-sectional view of a biometric sensing device according to another embodiment of the present disclosure. Figure 8 is a top view of the anti-counterfeiting area of a biometric sensing module according to another embodiment of the present disclosure. Figure 9 is a cross-sectional view along line 9-9 in Figure 8. Figure 10 is a graph showing the relationship between transmittance and wavelength of an infrared light blocking layer according to another embodiment of the present disclosure.

10b: Biometric identification device

100b: Biometric sensing module

1002a: Anti-counterfeiting area

110: Spectroscopic material layer

110G: Green filter layer

110B: blue filter layer

110N: Filter layer

112: Flat layer

120: Infrared light cutoff layer

130: First light shielding layer

132,142: opening

140:Second light shielding layer

144:Dielectric layer

150: Photosensitive element

160:Microlens array

162:Microlens

170: Spacer layer

172: Spacer column

180,182:Glass substrate

200:Electronic devices

220:Display panel

230:Cover

300:finger

Z: vertical direction

Claims (10)

A biometric sensing module including: A plurality of pixels, each of which includes: a layer of spectroscopic material; An infrared light cut-off layer is located below the light-splitting material layer; and A photosensitive element is located below the infrared light cutoff layer; The light-splitting material layer of one of the pixels includes a first filter layer and a second filter layer having different colors, and the first filter layer and the second filter layer are in a vertical direction. overlap. The biometric sensing module of claim 1, wherein the first filter layer is blue and the second filter layer is green. The biometric sensing module as described in claim 1, wherein the transmittance of the spectroscopic material layer in the wavelength band above 590 nanometers is less than 50%. The biometric sensing module as described in claim 1, wherein the infrared light cutoff layer has a transmittance of less than 10% in a wavelength band above 570 nanometers. The biometric sensing module according to claim 1, wherein the light-splitting material layer of one of the pixels further includes a green filter layer, and the green filter layer has a wavelength of 495 nanometers to 590 nanometers. The penetration rate in the meter range is greater than 50%. The biometric sensing module according to claim 1, wherein the light-splitting material layer of one of the pixels further includes a blue filter layer, and the blue filter layer has a wavelength of 400 nm to The penetration rate in the 495 nm range is greater than 50%. The biometric sensing module as described in request item 1 also includes: A first light-shielding layer is located between the infrared light-cutting layer and the photosensitive element, wherein the first light-shielding layer has a plurality of openings. The biometric sensing module as described in request item 7 also includes: A second light-shielding layer is located between the first light-shielding layer and the infrared light blocking layer or between the first light-shielding layer and the photosensitive element. The biometric sensing module of claim 1, wherein the infrared light cutoff layer has a transmittance greater than 20% in the wavelength range of 400 nanometers to 570 nanometers. The biometric sensing module of claim 1, wherein the infrared light cutoff layer has a transmittance greater than 50% in the wavelength range of 420 nanometers to 550 nanometers.

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