TWI688891B - Fingerprint identification apparatus - Google Patents

Abstract

A fingerprint identification apparatus includes a display element, a light controlling element, a sensing element, a light guiding element and a sensing light source. The light controlling element and the sensing element are respectively disposed on both sides of the display element. The light guiding element is disposed on the display element. The sensing light source provides a sensing light beam. The sensing light beam passing through the light controlling element enters the light guiding element at an angle α. The light controlling element is able to adjust the angle α.

Description

Fingerprint identification device

The invention relates to an optical device, and in particular to a fingerprint identification device.

Fingerprint identification devices can be divided into optical, capacitive, ultrasonic, and thermal. Taking the optical fingerprint identification device as an example, the principle of optical fingerprint identification is as follows.

The fingerprint of a finger is composed of many irregular peaks and troughs. When the finger presses the fingerprint recognition device, the wave peak contacts the fingerprint recognition device, while the wave valley does not contact the fingerprint recognition device. The wave peak directly diffuses the light beam to the sensing element, thereby forming a bright area. At the same time, the light beam irradiated to the trough will be reflected multiple times in the trough, and then transmitted to the sensing element, thereby forming a dark area. In this way, the light beams corresponding to the peaks and troughs of the fingerprint are formed as a staggered pattern of stripes on the light-receiving surface of the sensing element, and fingerprint images are obtained. Using the algorithm to calculate the information corresponding to the fingerprint image, the user's identity can be identified.

However, when the optical fingerprint identification device and the display panel are assembled into an electronic device with fingerprint identification (eg, mobile phone, computer, etc.), the user needs to press a specific area on the display panel of the electronic device to perform fingerprint identification, resulting in User inconvenience.

The invention provides a fingerprint identification device, which is convenient to use.

A fingerprint identification device of the present invention includes a display element, a dimming element, a sensing element, a light guide element, and a sensing light source. The dimming element and the sensing element are respectively disposed on both sides of the display element. The light guide element is disposed on the display element. The sensing light source provides the sensing beam. After passing through the dimming element, the sensing beam enters the light guide element at an angle α. The dimming element can adjust the angle α.

In an embodiment of the invention, the above-mentioned dimming element includes multiple substrates, optically anisotropic materials, and multiple electrodes. A plurality of substrates are arranged oppositely. The optically anisotropic material is disposed between the multiple substrates. The plurality of electrodes are provided on at least one of the plurality of substrates. The multiple electrodes have voltage differences to drive optically anisotropic materials.

In an embodiment of the invention, the above-mentioned dimming element further includes: a light homogenizing element, which is disposed between one of the plurality of substrates and the sensing light source.

In an embodiment of the invention, the above-mentioned light homogenizing element includes a grid-shaped light blocking pattern.

In an embodiment of the invention, the fingerprint identification device described above further includes a touch element and a processing and control element. The touch element is disposed on or in the display element. The processing and control element is electrically connected to the touch element and the dimming element. The processing and control element drives the dimming element according to the touch signal from the touch element to determine the range of the angle α.

In an embodiment of the present invention, the above-mentioned display element has a display area, and the dimming element and the sensing element are arranged in a direction. The display area includes a plurality of sub-display areas arranged along the direction; the dimming element changes the angle α , So that the sensing beam is transmitted to the multiple sub-display areas in time sequence.

In order to make the above-mentioned features and advantages of the present invention more obvious and understandable, the embodiments are specifically described below in conjunction with the accompanying drawings for detailed description as follows.

Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the drawings. Wherever possible, the same element symbols are used in the drawings and description to denote the same or similar parts.

It should be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” or “connected to” another element, it can be directly on or connected to the other element, or Intermediate elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to physical and/or electrical connections. Furthermore, the "electrically connected" or "coupled" system may be that there are other elements between the two elements.

As used herein, "about", "approximately", or "substantially" includes the stated value and the average value within an acceptable deviation range for a particular value determined by one of ordinary skill in the art, taking into account the measurements and A certain amount of measurement-related errors (ie, limitations of the measurement system). For example, "about" may mean within one or more standard deviations of the stated value, or within ±30%, ±20%, ±10%, ±5%. Furthermore, as used herein, "about", "approximately", or "substantially" can be based on optical properties, etching properties, or other properties to select a more acceptable range of deviation or standard deviation, and not one standard deviation can be applied to all properties .

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this invention belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology and the present invention, and will not be interpreted as idealized or excessive Formal meaning unless explicitly defined as such in this article.

FIG. 1 is a schematic cross-sectional view of a fingerprint identification device according to an embodiment of the invention. 2 is a three-dimensional schematic diagram of a fingerprint identification device according to an embodiment of the invention.

Please refer to FIGS. 1 and 2, the fingerprint identification device 100 includes a display element 110. In this embodiment, the display element 110 includes a display panel 112. The display panel 112 may include a pixel array substrate 112a, a counter substrate 112b, and a display medium 112c disposed between the pixel array substrate 112a and the counter substrate 112b.

For example, in this embodiment, the display medium 112c may be a non-self-luminous display medium (such as but not limited to: liquid crystal), and the display element 110 may include a backlight 118 disposed below the display panel 112. In addition, in this embodiment, the display element 110 may further include a polarizer 114 and a polarizer 116, which are respectively disposed on the pixel array substrate 112a and the counter substrate 112b. However, the present invention is not limited to this. According to other embodiments, the display medium 112c may also be a self-luminous display medium (such as but not limited to: an organic electroluminescent layer), and the display element 110 may not include the backlight 118; in addition, according to In other embodiments, the display element 110 may optionally not include the polarizer 114 and/or the polarizer 116.

The fingerprint recognition device 100 further includes a dimming element 120 and a sensing element 130, which are respectively disposed on both sides of the display element 110. The sensing element 130 is used to convert the sensing beam L into an electrical signal. For example, in this embodiment, the sensing element 130 may be a charge-coupled device (CCD) or a complementary metal oxide semiconductor active pixel sensor (CMOS Active pixel sensor), but the present invention does not This is the limit.

In this embodiment, the dimming element 120 may include a plurality of substrates 121, 122, a plurality of electrodes 123, 124, and an optically anisotropic material 125. The substrate 121 is opposite to the substrate 122. The optically anisotropic material 125 (for example, but not limited to: liquid crystal) is disposed between the plurality of substrates 121 and 122. The plurality of electrodes 123 and 124 are provided on at least one of the plurality of substrates 121 and 122. The electrode 123 and the electrode 124 are transparent. The electrode 123 and the electrode 124 have a voltage difference to drive the optically anisotropic material 125. The dimming element 120 further includes a driver 126 electrically connected to the electrodes 123 and 124 to provide a voltage difference between the electrode 123 and the electrode 124. In this embodiment, the dimming element 120 does not include a polarizer.

In this embodiment, the plurality of electrodes 123 and 124 of the dimming element 120 may be disposed on the plurality of substrates 121 and 122, respectively. However, the present invention is not limited to this. According to other embodiments, the plurality of electrodes 123, 124 of the dimming element 120 may also be disposed on the same substrate 121, as long as the voltage difference between the plurality of electrodes 123, 124 can drive optically different directions Sexual material 125 is enough.

In addition, in this embodiment, the dimming element 120 and the display element 110 may be two independent components; or one component integrated together. For example, if the dimming element 120 and the display element 110 are integrated together, the dimming element 120 and the display element 110 may share the upper and lower substrates; that is, the substrate 121 of the dimming element 120 and the pixel array of the display element 110 The base of the substrate 112a may be the same member, the base 122 of the dimming element 120 and the opposite substrate 112b of the display element 110 may be the same member, and the optically anisotropic material 125 of the dimming element 120 and the display element 110 A separation element (such as but not limited to: frame glue) can be selectively provided between the display media 112c.

In this embodiment, the dimming element 120 may further include a light homogenizing element 127, which is disposed between the substrate 121 and the sensing light source 150. The light homogenizing element 127 enables the sensing light beam L emitted by the sensing light source 150 to be uniformly transmitted to the optically anisotropic material 125 of the dimming element 120.

3 is a schematic top view of a light homogenizing device according to an embodiment of the invention. Please refer to FIGS. 1 and 3. For example, in this embodiment, the light uniformizing element 127 may include a grid-shaped light blocking pattern. The grid-shaped light-blocking pattern may have a plurality of meshes 127c with the same size and uniform density, and the sensing beam L can be uniformized after passing through the plurality of meshes 127c to be uniformly transmitted to the optically anisotropic material 125.

In this embodiment, the light homogenizing element 127 may have a plurality of light-shielding strips 127a extending in the direction x and a plurality of light-shielding strips 127b extending in the direction y, where the direction x is interleaved with the direction y. For example, the display element 110 and the light guide element 140 are stacked in the direction z, the direction x and the direction y are perpendicular to the direction z, and the direction x and the direction y may be perpendicular to each other, but the invention is not limited thereto.

Please refer to FIG. 1 and FIG. 2, the fingerprint identification device 100 further includes a light guide element 140 disposed on the display element 110. In this embodiment, the light guide element 140 is also disposed on the dimming element 120. The light guide element 140 has a surface 140 a facing the light adjustment element 120 and a surface 140 b for the finger F to press. In this embodiment, the light guide element 140 is a transparent material layer. For example, the material of the light guide element 140 may be Silica, Silicon, or other suitable materials.

The fingerprint recognition device 100 further includes a sensing light source 150 to provide a sensing beam L. For example, in this embodiment, the sensing light source 150 may be selectively the backlight 118 of the display element 110, but the invention is not limited thereto.

It is worth noting that the sensing beam L enters the light guide element 140 at an angle α after passing through the dimming element 120, and the dimming element 120 can adjust the angle α. In other words, the dimming element 120 can adjust the incident angle α of the sensing beam L entering the surface 140a of the light guide element 140. Thereby, the sensing light beam L can be transmitted from the inside of the light guide element 140 to the surface 140b of the light guide element 140 at various angles β, so that the sensing element 130 outputs an electrical signal corresponding to the fingerprint image of the finger F for fingerprint recognition.

Specifically, in this embodiment, the plurality of electrodes 123 and 124 of the dimming element 120 may have a voltage difference, and voltage differences of different magnitudes may cause the optical anisotropic medium 125 (such as but not limited to: liquid crystal) to rotate The angle is different. That is to say, by controlling the voltage difference of the plurality of electrodes 123 and 124 of the dimming element 120, the rotation angle of the optical anisotropic medium 125 (such as but not limited to: liquid crystal) can be controlled, thereby adjusting the incidence of the sensing beam L into the light guide element The angle α of 140.

FIG. 4 shows that the sensing light beam L according to an embodiment of the present invention is deflected by the optical anisotropic medium 125 during a plurality of successive first to seventh time intervals t1 to t7 (labeled in FIGS. 5A to 5G) according to the timing The multiple sensing light beams Lt1 ˜ Lt7 transmitted to the surface 140 b (shown in FIG. 1) of the light guide element 140.

FIGS. 5A to 5G show that the sensing beams Lt1 to Lt7 (marked in FIG. 4) according to an embodiment of the present invention are transmitted to a plurality of regions RLt1 to RLt7 above the display element 110 in the first to seventh time intervals t1 to t7, respectively. Situation.

Please refer to FIGS. 1, 4 and 5A to 5G. In this embodiment, the display element 110 has display areas 110a to 110g (labeled in FIGS. 5A to 5G), and the dimming element 120 and the sensing element 130 are in one Arranged in the direction x, the display areas 110a to 110g include a plurality of sub-display areas 110a, 110b, 110c, 110d, 110e, 110f, and 110g arranged along the direction x. The dimming element 120 changes the angle α to make the sensing beam Lt1 Lt2, Lt3, Lt4, Lt5, Lt6, and Lt7 are transmitted to the top of the plurality of sub-display areas 110a to 110g of the display element 110 in time sequence. That is, the sensing light beams Lt1, Lt2, Lt3, Lt4, Lt5, Lt6, and Lt7 respectively illuminate the plurality of regions RLt1 to RLt7 above the display element 110 in the successive first to seventh time intervals t1 to t7. Thereby, no matter where the finger F is placed above the display areas 110a to 110g of the display element 110, the sensing element 130 can receive the sensing beam L diffused by the finger F, thereby realizing full-screen optical fingerprint recognition装置100。 The device 100.

Please refer to FIG. 1. In this embodiment, the fingerprint recognition device 100 may optionally include a touch element TP and a processing and control element 160. The processing and control element 160 is electrically connected to the touch element TP and the dimming element 120. The processing and control element 160 drives the dimming element 120 according to a touch signal from the touch element TP to determine the range of the angle α.

In other words, the processing and control element 160 can determine the magnitude of the voltage difference between the multiple electrodes 123 and 124 of the dimming element 120 according to the finger touch position information carried by the touch signal, so that the sensing beam L scans the finger The area where F is located, and most of the area where non-finger F is located is not scanned. Thereby, the speed of acquiring the fingerprint image can be increased and the power consumption of the fingerprint recognition device 100 can be reduced.

Please refer to FIG. 1. In this embodiment, the touch element TP can be selectively disposed in the display element 110. In other words, the touch element TP may be an in-cell touch element. However, the present invention is not limited to this. According to other embodiments, the touch element TP may also be disposed at other appropriate positions, which will be illustrated below with reference to FIG. 6.

6 is a schematic cross-sectional view of a fingerprint identification device according to another embodiment of the invention. The fingerprint recognition device 100A of FIG. 6 is similar to the fingerprint recognition device 100 of FIG. 1, and the main difference between the two is that the location of the touch element TP of the fingerprint recognition device 100A is different from the location of the touch element TP of the fingerprint recognition device 100. Specifically, in the embodiment of FIG. 6, the touch element TP can be disposed on the display panel 112. In other words, the touch element TP may be an on-cell or an out-cell touch element. The fingerprint identification device 100A of FIG. 6 has similar functions and advantages as the fingerprint identification device 100 of FIG. 1 and will not be repeated here.

Although the present invention has been disclosed as above with examples, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention shall be subject to the scope defined in the appended patent application.

100, 100A: fingerprint recognition device 110: display element 110a～110g: display area 112: display panel 112a: Pixel array substrate 112b: Counter substrate 112c: Display media 114, 116: Polarizer 118: Backlight 120: dimming element 121, 122: substrate 123, 124: electrode 125: Optically anisotropic material 126: Drive 127: Light homogenizing element 127a, 127b: shading strip 127c: Mesh 130: sensing element 140: light guide element 140a, 140b: surface 150: Sensing light source 160: Processing and control elements F: finger L, Lt1～Lt7: sensing beam RLt1～RLt7: area t1～t7: time interval TP: touch element x, y, z: direction α, β: angle

FIG. 1 is a schematic cross-sectional view of a fingerprint identification device according to an embodiment of the invention. 2 is a three-dimensional schematic diagram of a fingerprint identification device according to an embodiment of the invention. 3 is a schematic top view of a light homogenizing device according to an embodiment of the invention. FIG. 4 illustrates a plurality of sensing beams that are deflected by an optically anisotropic medium and transmitted to the surface of the light guide element in time sequence in a plurality of successive first to seventh time intervals according to an embodiment of the present invention . FIGS. 5A to 5G illustrate the situation in which the sensing beams of one embodiment of the present invention are transmitted to multiple areas above the display element in the first to seven time intervals, respectively. 6 is a schematic cross-sectional view of a fingerprint identification device according to another embodiment of the invention.

100: fingerprint recognition device

110: display element

112: display panel

112a: Pixel array substrate

112b: Counter substrate

112c: Display media

114, 116: Polarizer

118: Backlight

120: dimming element

121, 122: substrate

123, 124: electrode

125: Optically anisotropic material

126: Drive

127: Light homogenizing element

130: sensing element

140: light guide element

140a, 140b: surface

150: Sensing light source

160: Processing and control elements

F: finger

L: sensing beam

TP: touch element

x, y, z: direction

α, β: angle

Claims (5)

A fingerprint identification device includes: a display element; a dimming element and a sensing element, which are respectively disposed on both sides of the display element, wherein the dimming element includes: a plurality of substrates, oppositely arranged; an optical anisotropy Materials are provided between the substrates; and a plurality of electrodes are provided on at least one of the substrates, wherein the electrodes have a voltage difference to drive the optically anisotropic material; a light guide element is provided On the display element; and a sensing light source, providing a sensing beam, wherein the sensing beam enters the light guide element at an angle α after passing through the dimming element, and the dimming element can adjust the angle α. The fingerprint identification device as described in item 1 of the patent application range, wherein the dimming element further includes: a light homogenizing element disposed between one of the substrates and the sensing light source. The fingerprint identification device as described in item 2 of the patent application range, wherein the light homogenizing element includes a grid-shaped light blocking pattern. A fingerprint identification device includes: a display element; a dimming element and a sensing element, which are respectively arranged on both sides of the display element; and a light guide element, which is arranged on the display element; A sensing light source provides a sensing beam, wherein the sensing beam enters the light guide element at an angle α after passing through the dimming element, and the dimming element can adjust the angle α; a touch element is provided at On or within the display element; and a processing and control element electrically connected to the touch element and the dimming element, wherein the processing and control element is driven according to a touch signal from the touch element The dimming element determines the range of the angle α. A fingerprint identification device includes: a display element; a dimming element and a sensing element, which are respectively arranged on both sides of the display element; a light guide element, which is arranged on the display element; and a sensing light source, providing A sensing beam, wherein the sensing beam enters the light guide element at an angle α after passing through the dimming element, and the dimming element can adjust the angle α; the display element has a display area, the dimming element and The sensing elements are arranged in a direction, and the display area includes a plurality of sub-display areas arranged in the direction; the dimming element changes the angle α so that the sensing beam is transmitted to the top of the sub-display areas in time sequence .

Images