TWM601858U - Display device - Google Patents

Abstract

A display device includes a display panel, a sensing light source and a fingerprint sensing module. The sensing light source has a first light emitting region and a second light emitting region, and the second light emitting region is annularly arranged at the periphery of the first light emitting region. The fingerprint sensing module is disposed on one side of the display panel, and receives the sensing light emitted from the sensing light source and penetrating the display panel to perform fingerprint detection.

Description

Display device

This creation is about a display device, especially a display device that uses a larger angle of incident light to illuminate fingerprints.

With the rise of smart electronic products, portable display devices, such as smart phones, tablet PCs, or laptop PCs, have become essential tools in people’s lives . As the functions become more and more diversified, private information such as phone books, photos, or personal identification information is usually stored in them. Due to the need for personal privacy and security and to protect private data, fingerprint sensing modules have been developed to be used in portable display devices.

When the user’s finger is relatively dry, there is an air gap between the ridge of the fingerprint and the screen, making the two incomplete contact. In addition, when light is irradiated on the ridge and valley of the fingerprint, diffuse reflection will appear. Or scattering (scattering). The above phenomena all cause the contrast value of the fingerprint image to drop significantly, which in turn causes recognition failure.

The technical problem to be solved by this creation is that when the user's fingers are relatively dry, the contrast value of the fingerprint image will be greatly reduced, which will cause the recognition failure.

In order to solve the above technical problems, the present invention provides a display device, which includes a display panel, a sensing light source, and a fingerprint sensing module. The sensing light source has a first light-emitting area and a second light-emitting area, wherein the second light-emitting area is annularly arranged on the periphery of the first light-emitting area. The fingerprint sensing module is arranged on one side of the display panel, and the fingerprint sensing module receives the sensing light emitted from the sensing light source and penetrating one of the display panels to perform fingerprint detection.

In the display device of this invention, the sensing light source can have a ring-shaped second light-emitting area, and can emit light with a larger incident angle through the second light-emitting area to illuminate finger fingerprints, and the contrast value of the second fingerprint image is less affected. The influence of diffuse reflection or scattering is reduced, thereby reducing the probability of identification failure.

Please refer to FIG. 1, the display device 10 may include a cover 100, a display panel 102, a sensing light source 104, and a fingerprint sensing module 106, wherein the display panel 102 may be disposed on the cover 100 and the fingerprint sensing module Between 106. The cover plate 100 can provide a function of protecting the display panel 102, and the cover plate 100 can include a transparent material, such as glass, plastic, or a combination thereof. The display panel 100 of this embodiment may be, for example, an organic light emitting diode (OLED) display panel, and part of the OLED elements or part of the pixels in the display panel 100 may be used as a sensing light for sensing fingerprints. Source 104. In other words, the sensing light source 104 of this embodiment can be disposed in the display panel 102, and the sensing light source 104 includes an organic light emitting diode.

In this embodiment, the sensing light source 104 for sensing fingerprints may have a first light-emitting area E1 and a second light-emitting area E2. As shown in FIG. 1, the first light-emitting area E1 may be a circular area, and the second light-emitting area E2 may be an annular area, and the second light-emitting area E2 may be annularly arranged on the periphery of the first light-emitting area E1. For example, the inner edge E21 of the second light-emitting area E2 may be located in the first light-emitting area E1, and the outer edge E23 of the second light-emitting area E2 may coincide with the edge E10 of the first light-emitting area E1. The shape of the second light-emitting area E2 in this embodiment may include a circle, and the inner edge E21 and the outer edge E23 may both be circular. In addition, the second light emitting area E2 may include an inner diameter R1 corresponding to the inner edge E21 and an outer diameter R2 corresponding to the outer edge E23, and the ratio of the inner diameter R1 to the outer diameter R2 may range from 1:10 to 9: 10. In addition, the outer diameter R2 of the second light-emitting area E2 of this embodiment may be the same as the diameter of the edge E10 of the first light-emitting area E1.

In the first fingerprint image capturing mode of the display device 10, the display device 10 can drive the OLED elements or pixels in the display panel 102 corresponding to the first light-emitting area E1 to emit sensing light (light L1 in FIG. 1). The fingerprint sensing module 106 can receive the sensing light emitted by the sensing light source 104 from the first light-emitting area E1 to generate a first fingerprint image. For example, the light L1 can illuminate the finger, and the fingerprint sensing module 106 can receive the light L2 reflected from the finger to measure a first fingerprint image. As shown in Fig. 1, light L1 and light L2 can be parallel to a normal direction N, and the incident angle and reflection angle can be regarded as zero degrees. For example, the normal direction N may be perpendicular to the upper surface of the display device 10 (the upper surface of the cover plate 100 in FIG. 1).

However, in some cases, when the finger is relatively dry, there is an air gap between the ridge of the fingerprint and the screen, so that the two cannot be in complete contact. In addition, when the light L1 irradiates the ridges and valleys of the fingerprint, diffuse reflection or scattering will occur, and the above phenomenon is the most serious in the direction of the light L2 reflected by the finger, resulting in the first fingerprint image The contrast value of is greatly reduced, which causes identification failure.

Therefore, this embodiment provides the second light-emitting area E2 and a second fingerprint imaging mode. In the second fingerprint imaging mode, the display device 10 can drive the OLED elements or pixels in the display panel 102 corresponding to the second light-emitting area E2 to emit sensing light (light L3 in FIG. 1). In some cases, when the finger is relatively dry, the sensing light (such as light L3) emitted by the second light-emitting area E2 can illuminate the finger with an incident angle α, and the incident angle α may be greater than 10 degrees, where the incident angle α It can be the angle between the light L3 and the normal direction N. In other words, compared to the incident angle of the light L1 in the first fingerprint imaging mode, in the second fingerprint imaging mode, the finger fingerprint is irradiated with the light L3 with a larger incident angle α. As shown in Figure 1, after light L3 illuminates the fingerprint of the finger, the finger can reflect light L4 and light L5, where light L4 can be parallel to the normal direction N, and light L5 can have a reflection angle β, where incident angle β can be light L5 The angle between and the normal direction N, and the angle of the reflection angle β may be substantially the same as the angle of the incident angle α.

The phenomenon of diffuse reflection or scattering will be the most serious in the direction of the light reflected by the finger L5. However, in the second fingerprint imaging mode, the fingerprint sensing module 106 can receive the sensing light source 104 emitted from the second light emitting area E1 The second fingerprint image is generated by sensing light. For example, the fingerprint sensing module 106 can receive the light L4 reflected from the finger to measure a second fingerprint image. Since the phenomenon of diffuse reflection or scattering is less serious in the direction of the light L4 reflected by the finger, the first The contrast value of the two fingerprint images is less affected and reduced, thereby reducing the probability of recognition failure.

As shown in FIG. 1, the fingerprint sensing module 106 of this embodiment can be arranged on one side of the display panel 102, and the fingerprint sensing module 106 can receive the sensing light emitted from the sensing light source 104 and penetrating the display panel 102 (such as The light L1 or the light L3) is the light reflected by the finger (such as the light L2 or the light L4), and the fingerprint is detected by this. The fingerprint sensing module 106 may include a sensing element 108 and a collimating element 110, wherein the collimating element 110 may be disposed between the sensing element 108 and the display panel 102. The sensing element 108 may include a thin film transistor (TFT) sensor, a complementary metal-oxide-semiconductor (CMOS) sensor, a photodiode, and other suitable sensors. Photoelectric conversion element or a combination of the above.

The collimating element 110 of this embodiment may include a plurality of microlenses 1102, a plurality of openings 1104, and a light shielding layer 1106. The opening 1104 can be disposed in the light shielding layer 1106 and can penetrate the light shielding layer 1106. In addition, the opening 1104 and the light shielding layer 1106 may be disposed between the micro lens 1102 and the sensing element 108. The microlens 1102 may include a material with high light transmittance or a transparent material, but is not limited thereto. The light-shielding layer 1106 can be used to improve the problem of crossover interference. The light-shielding layer 1106 can include opaque materials or light-absorbing materials, but is not limited to this.

On the other hand, this embodiment also provides a fingerprint sensing method for an electronic device, where the electronic device can be the display device 10 described above, but the fingerprint sensing method of this embodiment does not apply to the display device 10 as However, the fingerprint sensing method of this embodiment can also be applied to other suitable electronic devices. Please refer to FIG. 2, which is a flowchart of the fingerprint sensing method of the electronic device according to the first embodiment of the creation. The fingerprint sensing method of the electronic device (such as the display device 10) of this embodiment may include step S10 to step S16, and is not limited to the following sequence.

S10: Provide a display device;

S12: Provide a first fingerprint imaging mode in which sensing light is emitted through the first light-emitting area, and a first fingerprint image is measured through the fingerprint sensing module;

S14: Perform a fingerprint recognition using the first fingerprint image, if the recognition fails, continue with steps S16 and S18;

S16: Provide a second fingerprint imaging mode, in which sensing light is emitted through the second light-emitting area, and a second fingerprint image is measured through the fingerprint sensing module; and

S18: Perform a fingerprint recognition using the second fingerprint image.

For example, firstly, step S10 can be performed to provide the display device 10, wherein the elements and features of the display device 10 have been introduced above, and will not be repeated here. Then, step S12 can be performed to provide the first fingerprint imaging mode. As described above, the display device 10 can emit sensing light (light L1 in FIG. 1) through the first light-emitting area E1, and the fingerprint sensing module 106 can receive light reflected from a finger (light L2 in FIG. 1) , And the first fingerprint image can be measured through the fingerprint sensor module 106. When the first fingerprint image is greater than or equal to the preset threshold, the first fingerprint image may be considered sufficiently clear. At this time, step S16 may be performed to perform fingerprint recognition using the first fingerprint image.

However, in some cases, when the finger is relatively dry, the first fingerprint image is not clear enough and the recognition fails. Therefore, in this embodiment, the display device 10 (or electronic device) may perform steps S16-S18 to perform the second fingerprint imaging mode. As described above, the display device 10 can emit sensing light with a larger incident angle α through the second light-emitting area E2 (light L3 in FIG. 1), and the fingerprint sensing module 106 can receive the light reflected from the finger ( The light L4 in FIG. 1), and the second fingerprint image can be measured through the fingerprint sensor module 106.

Then, step S18 can be performed to perform fingerprint recognition using the second fingerprint image. As described above, the phenomenon of diffuse reflection or scattering is less serious in the direction of the light L4 reflected by the finger, which can increase the probability of successful fingerprint recognition.

Please refer to FIG. 3, which is a top view structure of the first light-emitting area and the second light-emitting area of the second embodiment of the creation. The difference from the first embodiment of FIG. 1 is that the shapes of the first light-emitting area E1 and the second light-emitting area E2 of this embodiment include rectangles. For example, the first light-emitting area E1 may be a rectangular area, and the second light-emitting area E2 may be a rectangular ring-shaped area, wherein the inner edge E21 and the outer edge E23 may both be rectangular.

Please refer to FIG. 4, which is a schematic diagram of the display device according to the third embodiment of the creation. The difference from the first embodiment of FIG. 1 is that the fingerprint sensing module 106 of this embodiment may include a sensing element 108 and a lens 112, wherein the lens 112 may be disposed between the sensing element 108 and the display panel 102 . The lens 112 may include a conventional optical lens, but is not limited thereto.

Please refer to FIG. 5, which is a schematic diagram of the display device of the fourth embodiment of the creation. The difference from the first embodiment in FIG. 1 is that the first light-emitting area E1 of the sensing light source 104 of this embodiment is located in the display panel 102, and the second light-emitting area E2 can be located in the display panel 102 and the fingerprint sensing module Between 106. In other words, the display device 10 of this embodiment may also have an external sensing light source 104'. In some embodiments, the display panel 102 may be an organic light emitting diode display panel, and the sensing light source 104' may include a light emitting diode (LED), a vertical cavity surface laser (vertical cavity surface), and a light emitting diode (LED). emitting laser, VCSEL) or a combination of the above. The external sensing light source 104' may have the second light-emitting area E2 introduced in the first embodiment, which will not be repeated here. In addition, the emitting half angle of the LED may range from 10 degrees to 80 degrees, and the view angle of the LED may range from 20 degrees to 160 degrees. On the other hand, the range of the half-angle of light emission of the VCSEL may be 10 degrees to 50 degrees, and the range of the viewing angle of the VCSEL may be 20 degrees to 100 degrees.

In other embodiments (as shown in FIG. 6), the display panel 102 may be a liquid crystal display panel, and the sensing light source 104 may be an external light source. The first light emitting area E1 and the second light emitting area E2 of the sensing light source 104 are both It is located between the display panel 102 and the fingerprint sensing module 106, and the sensing light source 104 may include OLED, LED, VCSEL or a combination of the above.

In summary, in the display device of the present invention, the sensing light source can have a ring-shaped second light-emitting area, and can emit light with a larger incident angle through the second light-emitting area to illuminate finger fingerprints. As shown in Figure 1, the phenomenon of diffuse reflection or scattering will be the most serious in the direction of the light L5 reflected by the finger. However, the fingerprint sensing module can receive the light L4 reflected from the finger to measure the second fingerprint image. Since the phenomenon of diffuse reflection or scattering is less serious in the direction of the light L4 reflected by the finger, the contrast value of the second fingerprint image is less affected and reduced, thereby reducing the probability of identification failure. In addition, this invention provides a fingerprint sensing method for electronic devices (or display devices). When the user’s fingers are relatively dry, the second fingerprint image can be measured through the second fingerprint imaging mode for recognition, which can improve the recognition success Probability.

10: Display device 100: cover 102: display panel 104,104’: Sensing light source 106: Fingerprint sensor module 108: sensing element 110: collimation element 1102: Micro lens 1104: Opening 1106: shading layer 112: lens E1: The first light-emitting area E10: Edge E2: second light emitting area E21: inner edge E23: Outer edge L1, L2, L3, L4, L5: light N: Normal direction R1: inner diameter R2: outer diameter S10-S18: steps α: incident angle β: reflection angle

FIG. 1 is a schematic diagram of the display device of the first embodiment of the creation. 2 is a flowchart of the fingerprint sensing method of the electronic device according to the first embodiment of the creation. 3 is a top view of the first light-emitting area and the second light-emitting area of the second embodiment of the creation. FIG. 4 is a schematic diagram of the display device of the third embodiment of the creation. FIG. 5 is a schematic diagram of the display device of the fourth embodiment of the creation. FIG. 6 is a schematic diagram of the display device of the fifth embodiment of the creation.

10: Display device

100: cover

102: display panel

104: Sensing light source

106: Fingerprint sensor module

108: sensing element

110: collimation element

1102: Micro lens

1104: Opening

1106: shading layer

E1: The first light-emitting area

E10: Edge

E2: second light emitting area

E21: inner edge

E23: Outer edge

L1, L2, L3, L4, L5: light

N: Normal direction

R1: inner diameter

R2: outer diameter

α: incident angle

β: reflection angle

Claims (10)

A display device includes: A display panel; A sensing light source having a first light-emitting area and a second light-emitting area, wherein the second light-emitting area is annularly arranged on the periphery of the first light-emitting area; and A fingerprint sensing module is arranged on one side of the display panel, and the fingerprint sensing module receives a sensing light emitted from the sensing light source and penetrating one of the display panels to perform fingerprint detection. The display device according to claim 1, wherein the second light-emitting area includes an inner diameter and an outer diameter, and a ratio of the inner diameter to the outer diameter ranges from 1:10 to 9:10. The display device according to claim 1, wherein the shape of the second light-emitting area includes a circle or a rectangle. The display device according to claim 1, further comprising a first fingerprint image or a second fingerprint image, and the fingerprint sensing module receives the sensing light from the sensing light source and generates the sensing light from the first light-emitting area A fingerprint image, or receiving the sensing light emitted by the second light-emitting area from the sensing light source to generate the second fingerprint image. The display device according to claim 1, wherein the first light-emitting area of the sensing light source is located in the display panel, and the second light-emitting area is located between the display panel and the fingerprint sensing module. The display device according to claim 1, wherein the first light-emitting area and the second light-emitting area of the sensing light source are both located in the display panel or between the display panel and the fingerprint sensing module. The display device according to claim 1, wherein the display panel is an organic light emitting diode display panel or a liquid crystal display panel. The display device according to claim 1, wherein the sensing light source includes an organic light-emitting diode, a light-emitting diode or a vertical cavity surface-emitting laser. The display device according to claim 1, further comprising a cover plate, wherein the display panel is disposed between the cover plate and the fingerprint sensing module. The display device according to claim 1, wherein the sensing light emitted through the second light-emitting area illuminates a finger at an incident angle, and the incident angle is greater than 10 degrees.

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