TWI750559B - Light sensing system and nanostructure layer - Google Patents

Abstract

A light sensing system having a structure including: a total reflection conductive layer having an upper surface and a lower surface, which configured to transmit in an optical information with total reflection in the total reflection conductive layer, wherein when an object contacts the upper surface of the total reflection conductive layer, the total reflection transmission of the optical information is destroyed and the optical information is output.; a light sensing layer is disposed below the total reflective conductive layer and configured to receive the optical information; a light output layer is disposed between the total reflection conductive layer and the light sensing layer, and directly or indirectly disposed on the lower surface of the total reflection conductive layer, the light output layer having a nano structure layer, the nano structure layer is configured to conduct the optical information which output from the total reflection conductive layer to the light sensor, and prevent the optical information from being reflected. Wherein, the light sensing layer is arranged directly or indirectly under the nano-structure layer, to receive the optical information which output by the nano-structure layer. Therefore, the invention can effectively improve the stability of the light sensing system, especially the accuracy of the light sensing layer.

Description

Optical sensing system and nanostructure layer

The present invention relates to a light sensing system, in particular, to a light sensing system that utilizes an anti-reflection nano-structure layer to realize full-screen under-screen sensing.

In recent years, the development of fingerprint identification has set off an upsurge again. At present, the application of fingerprint identification under the display screen on the market can be divided into three systems: traditional capacitive fingerprint identification, ultrasonic fingerprint identification, and optical fingerprint identification.

Among them, the optical fingerprint identification system is the most widely used, and its advantages are low cost, mature technology and less interference from ambient light. Its main principle is to rely on the sensor to project light, then obtain the reflected light and draw a fingerprint pattern, and finally compare it with the fingerprint image in the system memory to achieve the recognition function.

At present, in order to increase the sensing area of the conventional optical fingerprint identification system, the process technology of thin film transistor is generally used, and a-Si/m-Si can absorb the wavelength of visible light to generate electrical signals, and use it as a light source. sensor to create a large-screen light sensor. However, since the quantum efficiency of a-Si/m-Si is not high, it is necessary to obtain more intense optical information to improve the conversion of electrical information. Therefore, how to improve the signal-to-noise ratio of the received optical information is a problem that researchers should solve. one of the problems.

The present invention is accomplished based on the above-mentioned technical problems, and can provide a light sensing system, which can effectively improve the accuracy of the light sensor without increasing the thickness of the screen or a small amount, and can use a nanostructure layer to prevent light Information reflection, thereby improving the signal-to-noise ratio of optical information.

The object of the present invention is to provide a light sensing system with a total reflection conductive layer and a nanostructure layer, comprising: a total reflection conductive layer, configured to transmit optical information through total reflection therein, and when an object touches the top of the total reflection conductive layer When the surface is damaged, the total reflection of the optical information transmits and outputs the optical information; the light sensing layer is arranged under the total reflection conduction layer and is configured to receive the optical information; the light output layer is arranged between the total reflection conduction layer and the light output layer. and directly or indirectly disposed on the lower surface of the total reflection conductive layer, the light output layer has a nanostructure layer, and the nanostructure layer is configured to conduct the optical information output from the total reflection conductive layer to the light sensing layer wherein, the photo-sensing layer is disposed directly or indirectly under the nano-structure layer, and is configured to receive the optical information output by the nano-structure layer.

In an embodiment of the present invention, the optical information output by the external light source has high collimation, that is, it has a small divergence angle, so that the optical information transmitted by total reflection in the total reflection conductive layer is transmitted more efficiently. The long distance enables the light information transmitted to the light sensing layer to have a higher signal-to-noise ratio.

Preferably, in an embodiment of the present invention, the divergence angle ranges from 0.3 degrees to 5 degrees.

In an embodiment of the present invention, the nanostructure layer is formed on the surface of the total reflection conductive layer.

Preferably, in an embodiment of the present invention, the light output layer is disposed on the surface of the total reflection layer in a stamping manner to prevent reflection of the light information output from the total reflection layer and transmit the light information to the light sensing layer. .

Preferably, in another embodiment of the present invention, the light output layer is a thin film, and the thin film is adhered on the total reflection layer to prevent the reflection of the optical information output in the total reflection layer and transmit the optical information to the light. sensing layer.

Another object of the present invention is to provide a nanostructured layer for use in the above-mentioned light sensing system. The nanostructure layer is used to prevent reflection of the optical information output from the total reflection conductive layer, thereby causing attenuation of the optical information.

In one embodiment of the present invention, the nanostructures may be made of plastic.

In one embodiment of the present invention, the shape of the nanostructure may be a cone, such as a cone, a quadrangular pyramid, or a triangular pyramid, or a column such as a quadrangular prism, a cylinder, or an elliptical column, or any combination thereof.

In one embodiment of the present invention, the diameter and height of the shape of the nanostructure are between 10 nm and 100 nm.

In one embodiment of the present invention, the refractive index of the nanostructure is smaller than the refractive index of the total reflection layer.

In order for those skilled in the art to understand the purpose, features and effects of the present invention, the present invention is described in detail as follows by means of the following specific embodiments and in conjunction with the accompanying drawings.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, the same reference numbers refer to substantially the same elements. In the following description, when it is determined that the detailed description of the related prior art or configuration will obscure the technology to which the present disclosure is directed, the detailed description thereof will be omitted. In describing several embodiments, the introductory portion of this specification typically describes the same elements, and may be omitted in other embodiments.

Terms including ordinal numbers, such as first and second, may be used to describe various elements, but those elements are not limited by the terms. These terms are only used to distinguish one element from another.

1 is a conventional optical fingerprint identification system in the prior art, including an optical output device 101, a contact interface 102 and a light sensor 103. However, the under-screen optical fingerprint identification system currently used in smart phones on the market , limited by the size of the mobile phone, the traditional optical illumination system must be abandoned, and the light of the mobile phone panel is used as the light source. However, since the liquid crystal display panel itself cannot emit light by itself, the products with under-screen optical fingerprint recognition generally use the organic light-emitting display panel as the screen at present. Smartphones using organic light-emitting display panels as the screen, because organic light-emitting display panels are generally made by methods such as solid-state material evaporation or liquid material spin coating, there is at least a gap between pixels, so that light can be guaranteed. through. When the user's finger touches the screen, the light emitted by the screen of the organic light-emitting display panel will illuminate the finger area, and the reflected light will be transmitted to the sensor under the screen through the pixel gap of the screen, and the formed image will be regenerated. Compare and analyze the data stored in the database.

FIG. 2 is a schematic diagram of the light sensing system of the present invention. The light sensing system 200 shown in FIG. 2 includes: a total reflection conductive layer 201 , a light output layer 203 and a light sensing layer 204 , wherein the light output layer 203 includes a nanostructure layer 202 . As shown in FIG. 2, the optical information is output to the total reflection layer 201 for total reflection transmission, and the transmission range can reach the full screen, instead of only using the light of the panel itself in the optical sensing system as the light source of the optical sensing system , so it is possible to realize full-screen fingerprint recognition on a smartphone with a liquid crystal display panel or an organic light-emitting display panel as a screen.

Preferably, the total reflection conductive layer 201 may be a transparent material such as glass, ITO or TFT.

Wherein, as shown in FIG. 2 , the nanostructure layer 202 is disposed between the total reflection conductive layer 201 and the light sensing layer 204, and is directly or indirectly disposed on the lower surface of the total reflection layer 201, and the light output layer 203 is configured to The optical information output in the total reflection layer 201 is conducted to the light sensing layer 204, and the light output layer 203 has a nanostructure layer 202. The nanostructure layer 202 is used to conduct the optical information output from the total reflection conduction layer 201 to The light sensing layer 204 has the function of preventing the reflection of light information; the light sensing layer 204 can be disposed above or below the light output layer 204 , and is configured to receive the light information output by the light output layer 203 .

Preferably, FIG. 3 is a schematic diagram of an external light source 205 outputting optical information according to an embodiment of the present invention. As shown in FIG. 3 , when the external light source 205 outputs optical information, the optical information has a divergence angle θ, and when the divergence angle θ is larger, It means that the collimation of the external light source 205 is lower, so that when the optical information is transmitted through total reflection in the total reflection conductive layer 201, the later transmitted optical information may overlap with the earlier transmitted optical information due to the divergence angle θ to generate noise. , which reduces the signal-to-noise ratio of optical information. Conversely, when the divergence angle θ is smaller, the collimation of the external light source 205 is higher. Due to the concentration of the optical information, the traveling distance of the optical information can be longer and noise is not easily generated, which can effectively improve the signal-to-noise ratio of the optical information. The divergence angle of the light information output by the external light source 205 according to an embodiment of the present invention is between 0.3 degrees and 5 degrees, preferably between 0.4 degrees and 4 degrees, such as 0.5 degrees or 3 degrees. In this way, the external light source 205 according to an embodiment of the present invention has better collimation and a smaller divergence angle, which effectively improves the signal-to-noise ratio and concentrates the light, making fingerprint image recognition clearer and more accurate.

Preferably, FIG. 4 is a schematic diagram of a nanostructure layer according to an embodiment of the present invention. As shown in FIG. 4 , the nanostructure layer 202 includes a nanostructure 400 configured to prevent output from the total reflection conductive layer 201 . When the optical information is transmitted into the nanostructure 400, reflection or noise is generated, which causes the attenuation of the optical information or reduces its signal-to-noise ratio.

The shape of the nanostructure 400 may be a cone such as a cone, a quadrangular pyramid, or a triangular pyramid, or a column such as a quadrangular prism, a cylinder, or an elliptical column, or a combination of any of the above. It should be further explained that, from the viewpoint of obtaining sufficiently low reflection characteristics in all regions of the visible light region with wavelengths of 380 nm to 700 nm, the height of the nanostructure 400 will affect the reflectivity of visible light of different wavelengths, especially in visible light. There is a significant change in the long wavelength region. Therefore, according to an embodiment of the present invention, the height of the nanostructure 400 is between 10 nm and 100 nm, preferably between 20 nm and 90 nm, such as 30 nm or 80 nm.

In addition, if the distance between the shapes of the nanostructures 400 is extremely small compared to the wavelength of visible light, the distance will not affect the characteristics of the reflected light. , the reflectivity in the short wavelength region of visible light will have a significant impact. Therefore, according to an embodiment of the present invention, the diameter of the nanostructure 400 is between 10 nm and 100 nm, preferably between 20 nm and 90 nm, For example: 30nm or 80nm.

Preferably, according to an embodiment of the present invention, the angle between the shape of the nanostructures 400 and the input optical information can be adjusted according to the configuration of the photo-sensing layer 203 , that is, different photo-sensing elements. As the photo-sensing layer 203, it can have different angles, and at the same time, according to the images sensed by different photo-sensing layers 203, it can also be adjusted and corrected through software algorithms, so that the fingerprint images obtained in each direction are consistent. .

Preferably, according to an embodiment of the present invention, the nanostructure 400 may be made of plastic.

Preferably, according to an embodiment of the present invention, the light output layer 203 may be disposed on the lower surface of the total reflection conductive layer 201 by embossing. It should be further noted that, according to an embodiment of the present invention, the imprinting material may be hardened by chemical and/or physical procedures. Also, according to another embodiment of the present invention, the embossing material can be hardened by electromagnetic radiation and/or by temperature.

Preferably, according to an embodiment of the present invention, when the light output layer 203 is disposed on the lower surface of the total reflection conduction layer 201 by imprinting, the refractive index of the material used in the nanostructure 400 may be smaller than the total reflection conduction layer. Refractive index of layer 201 . Therefore, the refractive index of the material used in the nanostructure 400 may be between 1.2 and 1.55, preferably between 1.3 and 1.51. For example, the refractive index of the material is 1.45.

Preferably, according to another embodiment of the present invention, the light output layer 203 is a thin film with a thickness between 10 nm and 1000 nm, which can be attached to the lower surface of the total reflection conductive layer 201 . At this time, the refractive index of the material used in the nanostructure 400 may be smaller than the refractive index of the total reflection conductive layer 201, so the refractive index of the material used in the nanostructure 400 may be between 1.2 and 1.55, preferably Between 1.3 and 1.51, for example, the refractive index of the material is 1.45.

In an embodiment of the present invention, as shown in FIG. 5A , the light sensing system 510 includes: a total reflection conductive layer 201 , a nanostructure layer 202 , a liquid crystal display panel 511 , a backlight 512 and a light sensing layer 204 . Wherein, as shown in FIG. 5A , the external light source 513 includes a liquid crystal display panel 511 , a backlight panel 512 and a light sensing layer 204 . It should be further noted that the light sensing layer 204 according to an embodiment of the present invention is a transparent light sensing layer, so it can be disposed between the liquid crystal display panel 511 and the backlight panel 512 .

Specifically, as shown in FIG. 5A , first, the external light source 513 outputs optical information to the total reflection conductive layer 201 for total reflection transmission. When the object touches the total reflection conductive layer 201 , the total reflection transmission of the optical information is destroyed, so that the total reflection transmission of the optical information is destroyed. The total reflection conductive layer 201 outputs the optical information to the nanostructure layer 202 disposed below, wherein the nanostructure layer 202 has anti-reflection nanostructures 400; then, the optical information penetrates the liquid crystal display through the nanostructure layer 202 The panel 511 is then conducted to the light sensing layer 203 ; finally, the fingerprint image recognition is realized by the light sensing layer 204 .

Although FIG. 5A shows an embodiment of the light sensing system 510, the present invention is not limited thereto, and FIG. 5B shows the light sensing system 520 according to another embodiment of the present invention including: a total reflection conductive layer 201, a nanostructure layer 202 , the organic light emitting display panel 521 and the light sensing layer 204 . It is characterized in that when the organic light emitting display panel 521 is used, the thickness of the light sensing system 520 can be effectively reduced, so that its application range is wider. However, in the embodiments of the light emitter 120 shown in FIG. 5A and FIG. 5B , the light sensing layer 204 is disposed under the liquid crystal display panel 511 or the organic light emitting display panel 521 , so that the light sensing layer 204 is sensitive to fingerprint images. The clarity and accuracy of the recognition is reduced.

Therefore, as shown in FIG. 5C , a light sensing system 530 according to another embodiment of the present invention includes: a total reflection conductive layer 201 , a nanostructure layer 202 , a light sensing layer 204 , a liquid crystal display panel 511 and a backlight 512 . Wherein, as shown in FIG. 5A , the external light source 513 includes a liquid crystal display panel 511 and a backlight panel 512 . In this way, the clarity and accuracy of fingerprint image recognition by the effective light sensing layer 204 can be improved, but the present invention is not limited to this.

Further, as shown in FIG. 5D , in another embodiment of the present invention, the light sensing system 540 includes: a total reflection conductive layer 201 , a nanostructure layer 202 , a light sensing layer 203 and an organic light emitting display panel 521 . In this way, the clarity and accuracy of fingerprint image recognition by the effective light sensing layer 204 are improved, and the thickness of the light sensing system 540 is effectively reduced.

Thereby, the present invention has the following implementation effect and technical effect:

First, the present invention uses the total reflection conductive layer 201 to transmit light information through total reflection, instead of using the light of the panel as the light source, and at the same time, by disposing the light sensing layer 204 between the liquid crystal display panel 511 and the backlight panel 512 In this way, whether an organic light-emitting display panel or a liquid crystal display panel is used as the screen, the optical fingerprint recognition under the screen can be realized, thereby improving the versatility of the light sensing system according to an embodiment of the present invention.

Second, the present invention improves the noise ratio of the optical information output from the total reflection conductive layer 201 to the photo-sensing layer 204 by the nano-structure layer 202 having the anti-reflection nano-structure 400, so that the photo-sensing layer 204 The clarity and accuracy of fingerprint image recognition has been improved.

Thirdly, the present invention further effectively improves the identification speed and accuracy of the photo-sensing layer 204 by disposing the photo-sensing layer 204 directly under the nano-structure layer 202 .

The embodiments of the present invention are described above by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention; all other equivalent changes or modifications made without departing from the spirit disclosed in the present invention shall be included in the following patent scope Inside.

101: Optical output device 102: Contact interface 103: Light sensor 200: Light Sensing System 201: Total reflection conductive layer 202: Nanostructured layers 203: Light output layer 204: Light Sensing Layer 205: External light source 400: Nanostructures 510: Light Sensing System 511: LCD panel 512: Backlight board 513: External light source 520: Light Sensing System 521: Organic Light Emitting Display Panel 530: Light Sensing System 533: External light source 540: Light Sensing System θ: divergence angle

1 is an optical fingerprint identification system known in the prior art; 2 is a schematic diagram of the light sensing system of the present invention; 3 is a schematic diagram of an external light source outputting optical information according to an embodiment of the present invention; 4 is a schematic diagram of a nanostructured layer according to an embodiment of the present invention; 5A is a schematic diagram of a light sensing system according to another embodiment of the present invention; 5B is a schematic diagram of a light sensing system according to another embodiment of the present invention; 5C is a schematic diagram of a light sensing system according to another embodiment of the present invention; FIG. 5D is a schematic diagram of a light sensing system according to another embodiment of the present invention.

200: Light Sensing System

201: Total reflection conductive layer

202: Nanostructured layers

203: Light Sensing Layer

204: Light output layer

Claims (12)

A light sensing system, the structure of which includes: a total reflection conductive layer, which has an upper surface and a lower surface, and is used for total reflection transmission of an optical information in the total reflection conductive layer, wherein when an object touches the total reflection When the upper surface of the conduction layer is used, the total reflection transmission of the optical information is destroyed and the optical information is output; a light sensing layer is arranged under the total reflection conduction layer for receiving the optical information; a light The output layer is arranged between the total reflection conduction layer and the light sensing layer, and is directly or indirectly arranged on the lower surface of the total reflection conduction layer, the light output layer has a nanostructure layer, the nanostructure The layer is used for conducting the optical information output from the total reflection conducting layer to the optical sensing layer, which has the function of preventing the reflection of optical information; wherein, the optical sensing layer is disposed directly or indirectly on the nanostructure layer below, to receive the optical information output by the nanostructure layer. The light sensing system of claim 1, wherein the light sensing layer is disposed under the light output layer. The light sensing system of claim 1, wherein the nanostructure layer is formed on a surface of the light output layer, and the light output layer is located on a lower surface of the total reflection conductive layer. The light sensing system according to claim 1, wherein the light output layer is disposed on the lower surface of the total reflection conductive layer in a stamping manner to prevent the output from the total reflection conductive layer. The optical information is reflected and transmitted to the optical sensing layer. The light sensing system of claim 1, wherein the light output layer is a thin film, and the thin film is adhered to the lower surface of the total reflection conductive layer to prevent output from the total reflection conductive layer The optical information is reflected, and the optical information is transmitted to the optical sensing layer. A nanostructure layer, which is used in the light sensing system as described in claim 1, includes a nanostructure for preventing reflection of an optical information output in a total reflection conductive layer, and transmits it. The optical information is sent to a photo-sensing layer. The nanostructure layer as claimed in claim 6, wherein the shape of the nanostructure is set as a cone shape, a column shape, or any combination thereof. The nanostructure layer as described in item 6 of the claimed scope is formed on the lower surface of the total reflection conductive layer. The nanostructure layer according to claim 7, wherein the diameter and height of the shape of the nanostructure are both between 10 nm and 100 nm. The nanostructured layer as described in claim 7, wherein the nanostructured layer is made of plastic. The nanostructure layer as described in claim 7, wherein the refractive index of the nanostructure is smaller than the refractive index of the total reflection conductive layer. The nanostructure layer according to claim 11, wherein the refractive index of the nanostructure is between 1.3 and 1.5.

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