Under-screen fingerprint identification device

Abstract

An under-screen fingerprint identification device includes an image sensing element, a display element, an optical lens, and a band pass filter element. The band pass filter element is disposed between the image sensing element and the display element. An object to be identified reflects an initial beam to generate a sensing beam, and the sensing beam is transmitted to the image sensing element through the display element, the optical lens, and the band pass filter element. The band pass filter element allows a beam with a specific wavelength range to pass. The specific wavelength range and a wavelength range of the initial beam are partially overlapped.

What is claimed is: 
     
         1 . An under-screen fingerprint identification device comprising:
 a display element;   an image sensing element disposed below the display element;   an optical lens disposed between the image sensing element and the display element; and   a band pass filter element disposed between the image sensing element and the display element, wherein an object to be identified is disposed on the display element, an initial beam is incident to the object to be identified, the object to be identified reflects the initial beam to generate a sensing beam, and the sensing beam is transmitted to the image sensing element through the display element, the optical lens, and the band pass filter element;   the band pass filter element allowing a beam with a specific wavelength range to pass, the specific wavelength range and a wavelength range of the initial beam being partially overlapped.   
     
     
         2 . The under-screen fingerprint identification device according to  claim 1 , wherein the wavelength range of the initial beam is within a range from λ L1  to λ L2 , the sensing beam comprises a first sub-beam, an incidence angle θ 1  between the first sub-beam and a normal line of the band pass filter element is substantially 0°, the band pass filter element has a first filter frequency spectrum corresponding to the first sub-beam, a transmittance rate corresponding to the first filter frequency spectrum at a wavelength λ F11  and a wavelength λ F12  is 50%, the wavelength λ F11  is shorter than the wavelength λ F12 , and λ L1 ≤λ F11 <λ L2 . 
     
     
         3 . The under-screen fingerprint identification device according to  claim 1 , wherein the band pass filter element is disposed between the image sensing element and the optical lens. 
     
     
         4 . The under-screen fingerprint identification device according to  claim 1 , wherein the band pass filter element is disposed between the display element and the optical lens. 
     
     
         5 . The under-screen fingerprint identification device according to  claim 2 , wherein the sensing beam further comprises a second sub-beam, an incidence angle θ 2  between the second sub-beam and the normal line of the band pass filter element is greater than the incidence angle θ 1  between the first sub-beam and the normal line of the band pass filter element, the band pass filter element has a second filter frequency spectrum corresponding to the second sub-beam, a transmittance rate corresponding to the second filter frequency spectrum at a wavelength λ F21  and a wavelength λ F22  is 50%, the wavelength λ F21  is shorter than the wavelength λ F22 , and λ F21 <λ F11 . 
     
     
         6 . The under-screen fingerprint identification device according to  claim 5 , wherein λ L4 ≤λ F21 <λ F11 . 
     
     
         7 . The under-screen fingerprint identification device according to  claim 5 , wherein λ F21 <λ L1 . 
     
     
         8 . The under-screen fingerprint identification device according to  claim 1 , wherein a full width at half maximum of the first filter frequency spectrum is greater than a full width at half maximum of the initial beam. 
     
     
         9 . The under-screen fingerprint identification device according to  claim 1 , wherein the display element emits the initial beam. 
     
     
         10 . An under-screen fingerprint identification device configured to identify an object to be identified and comprising:
 a display element;   an image sensing element disposed below the display element;   an optical lens disposed between the image sensing element and the display element, wherein an initial beam generates a light spot on the display element, the light spot comprises a central portion and a peripheral portion outside the central portion, and a brightness of the peripheral portion is greater than a brightness of the central portion.   
     
     
         11 . The under-screen fingerprint identification device according to  claim 10 , wherein the initial beam comprises a central sub-beam and a peripheral sub-beam, the central sub-beam defines the central portion of the light spot on the display element, the peripheral sub-beam defines the peripheral portion of the light spot on the display element, the central sub-beam passes through an optical axis region of the optical lens, and the peripheral sub-beam passes through a peripheral region of the optical lens.