Method for optically detecting a fingerprint or an object, and device with at least one screen

• US 9,958,988 B2
• Filed: 05/21/2014
• Issued: 05/01/2018
• Est. Priority Date: 06/12/2013
• Status: Active Grant

• Current Assignee: Dan Hossu
• Original Assignee: Dan Hossu
• Inventors: Hossu, Dan
• Primary Examiner(s): BEKELE, MEKONEN T
• Application Number:
  US14/893,006
• Publication Number:
  US 20160110025A1
• Time in Patent Office: 1,441 Days
• Field of Search: 382124, 382115, 345173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 40/1318 using electro-optical elements or layers, e.g. electroluminescent sensing
• CPC Class Codes: H10K 59/40 OLEDs integrated with touch screens
• CPC Class Codes: H10K 59/65 OLEDs integrated with inorganic image sensors

Abstract

In a method for optically capturing a fingerprint or an object on a surface (2) of a cover plate (1) of a screen with a plurality of photosensors (4) which are each assigned to a respective display pixel (6), the display pixels (6) emit light radiation and the photosensors (4) capture light radiation from the display pixels (6) reflected by the surface (2) within a scan angle (8). The scan angle (8) describes in a virtual mirror image plane (9) the size of the display pixel (6).

Claims

1. A method for optically capturing a fingerprint or an object on a surface (2) of a cover plate (1) of a screen, comprising the following steps:

providing a plurality of photosensors (4);

providing a plurality of display pixels (6);

assigning each of said photosensors (4) to a respective display pixel (6), wherein the display pixels (6) emit light radiation and the photosensors (4) capture light radiation from the display pixels (6) reflected by the surface (2) of the cover plate (1) of the screen within a scan angle (8), wherein the scan angle (8) corresponds in a virtual mirror image plane (9) to the size of a selected one of the display pixels (6), and wherein the scan angle (8) does not exceed the following size;

α

≤

2 arctan(d/4h₁)

wherein;

α

=scan angle 8

d=edge length of the display pixel 6

h₁=distance from the upper side of the display pixel to the surface 2 of the cover plate.

2. The method as defined in claim 1, wherein, for capturing a fingerprint, a plurality of display pixels (6) emit light radiation, wherein a proportion of said light radiation that is emitted and that are reflected by the surface (2) are received by the photosensor (4) that is respectively assigned to the display pixel (6).

3. The method as defined in claim 1, wherein, for capturing the object placed on the surface, a plurality of display pixels (6), emit light radiation to form a chessboard pattern, wherein reflected proportions of said light radiation that is emitted are received by the photosensor (4) that is respectively assigned to the display pixel (6) that emits no light radiation.

4. The method as defined in claim 3, wherein the object is a document (10) placed on the surface (2).

5. The method as defined in claim 3, wherein the display pixels (6) are arranged in the form of a matrix or in columns and lines.

6. The method as claimed in claim 3, wherein, for recording two half images of the object that can be combined to form one image, the display pixels (6) sequentially emit light radiation or the photosensors (4) associated with the display pixels (6) receive reflected light radiation.

7. An apparatus for performing the method as defined in claim 1, comprising:

at least one screen comprising an upper optical cover plate (1);

a plurality of display pixels (6) arranged under said upper optical cover plate (1) as light sources for an image to be represented; and

a plurality of photosensors, wherein a respective one of the photosensors is assigned in each case in a centered fashion to a plurality of display pixels (6).

8. The apparatus as defined in claim 7, wherein the photosensors (4) are arranged in a central free space of the associated display pixel (6) and are surrounded by subpixels (5).

9. The apparatus as defined in claim 7, wherein the photosensors (4) are arranged on a side of the display pixels (6) that is opposite the cover plate (1), wherein each display pixel (6) comprises a plurality of subpixels (5).

10. The apparatus as defined in claim 7, wherein at least one of the display pixels (6) or a subpixel (5) of the display pixel (6) emits radiation in the infrared or ultraviolet range.

11. The apparatus as defined in claim 7, wherein the display pixels (6) or subpixels (5) of the display pixels (6) emit monochromatic or colored light.

12. The apparatus as defined in claim 7, wherein the display pixels (6) are component parts of an OLED.

13. The apparatus as defined in claim 7, wherein each photosensor (4) comprises a color filter and/or each photosensor (4) is assigned a mask (7) for screening against direct illumination by the display pixels (6).

14. The apparatus as defined in claim 13, wherein the mask (7) is a metallized mask.

15. The apparatus as defined in claim 7, wherein each photosensor (4) comprises a plurality of sub-photosensors with one color filter.

16. The apparatus as defined in claim 7, wherein each photosensor (4) or at least one of its sub-photosensors is sensitive to infrared light and/or comprises an infrared filter.

17. The apparatus as defined in claim 7, wherein each photosensor (4) is assigned a microlens (3).

18. The apparatus as defined in claim 7, wherein the microlens (3) is configured as a Fresnel lens or a holographic lens.

19. The apparatus as defined in claim 7, wherein the microlens (3) is arranged between the cover plate (1) and the photosensor (4).

20. The apparatus as defined in claim 7, wherein the screen is configured as a touch screen.

21. The apparatus as defined in claim 7, wherein at least the display pixels (6) and the photosensors (4) are connected to a computer unit and a memory module.

22. The apparatus as defined in claim 7, further comprising a switching device, wherein said switching device is coupled to a computer unit to actuate either a fingerprint recognition mode, wherein in in said fingerprint recognition mode, all display pixels (6) emit light radiation and the photosensors (4) of said display pixels (6) that are assigned thereto capture reflected light radiation, or a scan mode, wherein in said scan mode, the display pixels (6) are switched on and off sequentially in the pattern of a chessboard so as to emit light radiation, and the photosensors (4) of the respectively switched-off display pixels (6) are switched on to receive the reflected light radiation.

23. The apparatus as defined in claim 7, wherein the cover plate (1) is configured as a flexible plastic film.

24. The apparatus as defined in claim 23, wherein the plastic film is uncoated, hard-coated or covered by a further film, and/or consists of a plurality of layers film.

25. The apparatus as defined in claim 23, wherein the further film is a graphene film.

26. The use of the apparatus as defined in claim 7 as a fingerprint sensor and/or a document scanner and/or a touch screen for a mobile telephone, a smart phone, a tablet computer and/or a stationary work screen computer.