WO2021169950A1 - 衍射抑制光学部件设计方法、显示屏和屏下摄像装置 - Google Patents

衍射抑制光学部件设计方法、显示屏和屏下摄像装置 Download PDF

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Publication number
WO2021169950A1
WO2021169950A1 PCT/CN2021/077458 CN2021077458W WO2021169950A1 WO 2021169950 A1 WO2021169950 A1 WO 2021169950A1 CN 2021077458 W CN2021077458 W CN 2021077458W WO 2021169950 A1 WO2021169950 A1 WO 2021169950A1
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Prior art keywords
display screen
diffraction suppression
optical component
area
diffraction
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PCT/CN2021/077458
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English (en)
French (fr)
Inventor
范真涛
冯辉
张恺
窦晨浩
吴皓
田克汉
Original Assignee
嘉兴驭光光电科技有限公司
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Priority to EP21761566.5A priority Critical patent/EP4113487A4/en
Priority to US17/802,734 priority patent/US11693253B2/en
Publication of WO2021169950A1 publication Critical patent/WO2021169950A1/zh

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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/42—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
    • G02B27/4205—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/0012—Optical design, e.g. procedures, algorithms, optimisation routines
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/18—Diffraction gratings
    • G02B5/1866—Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/57—Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/02—Constructional features of telephone sets
    • H04M1/0202—Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets
    • H04M1/026—Details of the structure or mounting of specific components
    • H04M1/0264—Details of the structure or mounting of specific components for a camera module assembly
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/02—Constructional features of telephone sets
    • H04M1/0202—Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets
    • H04M1/026—Details of the structure or mounting of specific components
    • H04M1/0266—Details of the structure or mounting of specific components for a display module assembly

Definitions

  • the present invention generally relates to under-screen imaging technology, and particularly relates to a design method of diffraction suppression optical components, a diffraction suppression display screen, and an under-screen imaging device that can be used to improve the imaging quality of under-screen imaging.
  • the existing technology proposes to place the front camera under the screen to completely hide the front camera, thereby completely realizing the full screen.
  • the display screen due to the presence of the display screen, it has a greater impact on the shooting effect of the camera under the screen.
  • the periodically arranged unit pixels will form a starburst effect due to the diffraction effect under strong light irradiation, thereby affecting the image quality.
  • the object of the present invention is to provide a diffraction suppression optical component, a diffraction suppression display screen, and an under-screen camera device, which can be used to suppress diffraction in the under-screen camera device, thereby improving image quality.
  • a design method of a diffraction suppression optical component for a transparent display screen which includes:
  • the design method may further include:
  • the value of the distance d is changed in the range of 0.1 to 5 mm, and more preferably the value of the distance d is changed in the range of 0.3 to 2 mm.
  • the diffraction suppression optical component may be a diffractive optical element including a substrate layer and a relief layer
  • the design method further includes: according to the transmittance function t 2 (x 2 , y 2 ) Determine the structure of the relief layer of the diffractive optical element and/or determine the material refractive index and thickness of the substrate layer of the diffractive optical element according to the distance d.
  • the step (a) may include: calculating the transmittance function t 1 (x 1 , y 1 ) based on the optical parameters and geometric parameters of the layer structure of the transparent display screen.
  • a diffraction suppression display screen which includes: a display screen that allows light to pass therethrough and includes periodically arranged pixel units; and a first diffraction suppression optical component that is disposed at A distance d from the display screen, where the display screen has a first transmittance function t 1 (x 1 , y 1 ), so that when a plane wave The complex amplitude distribution of the light field obtained by entering the display screen and propagating the distance d after transmission is The diffraction suppression optical component has a second transmittance function And meet C is a constant.
  • the distance d is preferably in the range of 0.1 to 5 mm, and more preferably in the range of 0.3 to 2 mm.
  • the second diffraction suppression optical component may be integrated inside the display screen or arranged between the display screen and the first diffraction suppression optical component.
  • the second diffraction suppressing optical component includes a sheet-shaped body including: a first area periodically arranged; and a first area approximately in a strip shape arranged around the first area. A second area; and a transition area, located at the edge of the second area.
  • the transition area extends from the edge position of the second area along the normal direction of the edge toward the first area, the first area is a light-transmitting area, and the second area includes at least at the edge position In the opaque area, the transmittance of the transition area changes in its extending direction.
  • the opaque area and the first area of the second diffraction suppression optical component at the edge of the second area respectively correspond to the edge of the adjacent pixel unit and the corresponding pixel unit of the light-shielding band of the display screen.
  • the change in the transmittance of the transition region of the second diffraction suppression optical component in the extending direction conforms to the apodization function, and the apodization function is selected from one of a linear function, a Blackman function, a Connes function, and a Gaussian function .
  • the transition area of the second diffraction suppression optical component includes an opaque portion and a transparent portion, and the transmittance of the transition area is determined by the ratio between the opaque portion and the transparent portion.
  • the second diffraction suppressing optical component is formed as a sheet-like member including a first area periodically arranged in a two-dimensional manner and a first area approximately in a strip shape arranged around the first area.
  • the second area, the first area is a light-transmitting area, wherein the second area has a plurality of unit patterns arranged along the extending direction of the strip shape occurring in a transverse direction perpendicular to the extending direction
  • the shape is generated by random displacement, and the second region is opaque at least on its two side edge portions.
  • an under-screen camera device which includes: the above-mentioned diffraction suppression display screen, the diffraction suppression display screen having a display surface for display and a back surface opposite to the display surface; And a camera, which is arranged on the back side of the diffractive display screen, and is used to image an object located on the side of the display surface of the diffractive display screen.
  • the phase-type diffraction suppression optical component provides phase modulation, thereby suppressing the diffraction effect in the under-screen device, and improving the imaging quality of the under-screen imaging.
  • Fig. 1 schematically shows an example of an electronic device incorporating an under-screen camera device according to an embodiment of the present invention
  • FIG. 2 is a schematic diagram of an under-screen camera device according to the first embodiment of the present invention.
  • FIG. 3 is a schematic flowchart of an example of a design method of a diffraction suppression optical component according to an embodiment of the present invention
  • Fig. 4 schematically shows an example of a periodic structure of pixels in a transparent display screen
  • Fig. 5 schematically shows a phase modulation distribution diagram of an example of a phase-type diffraction suppression optical component according to an embodiment of the present invention
  • Fig. 6 shows the MTF curve obtained by combining the phase-type diffraction suppression optical component shown in Fig. 5 with the transparent display screen;
  • FIG. 7 shows a simulation data chart of the diffraction suppression effect obtained by combining the phase-type diffraction suppression optical component and the transparent display screen shown in FIG. 5;
  • Fig. 8 schematically shows a phase modulation distribution diagram of another example of a phase-type diffraction suppression optical component according to an embodiment of the present invention.
  • FIG. 9 shows the MTF curve obtained by combining the phase-type diffraction suppression optical component shown in FIG. 8 with the transparent display screen;
  • FIG. 10 shows a simulation data chart of the diffraction suppression effect obtained by combining the phase-type diffraction suppression optical component and the transparent display screen shown in FIG. 8;
  • FIG. 11 is a schematic diagram of an under-screen camera device according to the second embodiment of the present invention.
  • FIG. 12 is a schematic diagram of an example of an amplitude-type diffraction suppressing optical component that can be used in the present invention.
  • FIG. 13 shows a schematic diagram of an opaque gray scale unit in the transition region of the amplitude-type diffraction suppression optical component shown in FIG. 12;
  • FIG. 14 shows a schematic diagram of a gray scale unit with a certain degree of transparency in the transition area of the amplitude-type diffraction suppression optical component shown in FIG. 12;
  • FIG. 15 schematically shows a phase modulation distribution diagram of another example of a phase-type diffraction suppression optical component according to an embodiment of the present invention.
  • FIG. 16 shows the MTF curve obtained by combining the amplitude-type diffraction suppression optical component shown in FIG. 12, the phase-type diffraction suppression optical component shown in FIG. 15 and the transparent display screen;
  • FIG. 17 shows a simulation data chart of the diffraction suppression effect obtained by combining the amplitude-type diffraction suppression optical component shown in FIG. 12 and the phase-type diffraction suppression optical component shown in FIG. 15 with the transparent display screen;
  • FIG. 18 is a schematic diagram of another example of an amplitude-type diffraction suppressing optical component that can be used in the present invention.
  • FIG. 19 is a schematic diagram of an under-screen camera device according to Embodiment 3 of the present invention.
  • 20 is a schematic diagram of an under-screen camera device according to the fourth embodiment of the present invention.
  • FIG. 1 schematically shows an example of an electronic device incorporating an under-screen camera device 1 according to an embodiment of the present invention, a smart phone 2.
  • the smart phone 2 may have a full screen, and the under-screen camera 1 may be constructed under at least a part of the full screen.
  • FIG. 2 is a schematic diagram of the under-screen camera device 1 according to the first embodiment of the present invention.
  • the under-screen camera device 1 includes a diffraction suppression display screen 10 and a camera 20 according to an embodiment of the present invention.
  • the diffraction suppression display screen 10 includes a transparent display screen 11 and a diffraction suppression optical component 12.
  • the transparent display screen 11 allows light to pass therethrough, and has a display surface 11a for display.
  • the diffraction suppression optical member 12 is provided on the side of the display screen 11, preferably on the back side of the display screen 11 opposite to the display surface 11a as shown in FIG.
  • the diffraction suppression optical component 12 is an optical component that suppresses diffraction by phase modulation of incident light, and has a small influence on the amplitude of incident light, and is hereinafter referred to as a phase-type diffraction suppression optical component.
  • the display surface 11a is also configured as a display surface of the diffraction suppression display screen 10 at the same time.
  • the camera 20 is disposed on the side of the diffraction suppression display screen 10 opposite to the display surface 11a, and is used to receive light transmitted through the display screen 11 and the diffraction suppression optical member 12 and perform imaging. As shown in FIG. 2, the camera 20 includes, for example, an imaging lens 21 and an image sensor 22.
  • the internal structure of the display screen 11, especially the periodically arranged pixel units, will diffract the light passing through the display screen 11, the imaging quality of the camera 20 will be affected, especially the starburst effect will occur.
  • the entire optical The modulation transfer function (MTF, Modulation Transfer Function) of the system will also decrease.
  • a phase-type diffraction suppression optical component 12 is added, which is arranged at a distance d from the display screen 11.
  • the display screen 11 has a first transmittance function t 1 (x 1 , y 1 ), so that when a plane wave The complex amplitude distribution of the light field obtained after entering the display screen 11 and transmitting through the propagation distance d is Then the second transmittance function of the diffraction suppression optical component 12 is satisfy C is a constant.
  • the distance d is preferably set in the range of 0.1 to 5 mm, and in some examples, it is more preferably set in the range of 0.3 to 2 mm.
  • the diffraction suppression optical component 12 is a diffractive optical element (DOE, Diffractive Optical Element).
  • DOE diffractive optical element
  • FIG. 3 is a schematic flowchart of an example of a design method of the diffraction suppression optical component 12 according to an embodiment of the present invention. As shown in FIG. 3, the design method 3 of the diffraction suppression optical component 12 includes:
  • S3b Calculate a plane wave based on the transmittance function t 1 (x 1 , y 1) of the transparent display screen 11 The complex amplitude distribution of the light field on a plane at a distance d from the transparent display after passing through the transparent display
  • S3c Design the diffraction suppression optical component 12 so that it has a transmittance function And satisfied C is a constant.
  • the transmittance function t 1 (x 1 , y 1 ) of the transparent display screen 11 can be achieved by illuminating the display screen 11 with a known light field and measuring the transmittance through the display screen 11. The light field is measured and can also be calculated based on the optical parameters and geometric parameters of the layer structure of the transparent display screen.
  • step S3b it can be based on plane wave
  • the light field complex amplitude distribution U(x 2 , y 2 , d) is calculated by perpendicularly incident on the display screen 11; it can also be based on the light field under non-perpendicular incident or incident at different multiple angles, for example.
  • the diffraction suppression optical component design method 3 may further include:
  • S3e Corresponding to different distances d, based on the transmittance function t 1 (x 1 , y 1 ) of the transparent display screen and the transmittance function t 2 (x 2 , y 2 ) of the diffraction suppression optical components.
  • the simulation calculation includes The diffraction suppression effect or modulation transfer function of the optical system of the transparent display screen and the diffraction suppression optical component, and compare the diffraction suppression effect or modulation transfer function to select the value of the distance d and the corresponding transmittance of the diffraction suppression optical component Function t 2 (x 2 ,y 2 ).
  • step S3b and step S3c it is preferable to adjust the value of the distance d within a certain range, repeat step S3b and step S3c, and calculate and compare the values of the optical system including the display screen 11 and the diffraction suppression optical component 12 under different distance d values.
  • Diffraction suppression effect or modulation transfer function is selected to select the transmittance function t 2 (x 2 , y 2 ) of the diffraction suppression optical component 12 corresponding to a relatively better diffraction suppression effect or modulation transfer function.
  • the design of diffraction suppression optical components can be based on vector diffraction theory or scalar diffraction theory. However, due to the complicated derivation process of vector diffraction theory and the huge amount of calculation, it is generally more inclined to use scalar diffraction theory for approximate calculation.
  • the inventor found through simulation that when the distance d is too small, that is, less than 0.1mm, the approximate calculation using the scalar diffraction theory will seriously deviate from the actual situation, resulting in the phase-type diffraction suppression optical components calculated and designed according to the scalar diffraction theory failing to meet expectations.
  • Technical effect since the under-screen camera device involved in the present invention is mainly used in portable communication devices, such as smart phones, tablet computers, etc., these devices are usually thin, so the distance d should not be too large.
  • the diffraction suppression optical member 12 is a diffractive optical element and includes a substrate layer and a relief layer.
  • the diffraction suppression optical component design method 3 may further include:
  • S3f Determine the structure of the relief layer of the diffractive optical element according to the transmittance function t 2 (x 2 , y 2 ) and/or determine the material refractive index and thickness of the substrate layer of the diffractive optical element according to the distance d.
  • the distance between the display screen 11 and the diffraction suppression optical component 12 is strictly controlled.
  • the distance d is not easy, so if the optical path length equivalent to the distance d (in air) is realized by designing, for example, the substrate layer of the diffraction suppression optical component 12, for example, the display screen 11 and the diffraction suppression optical component 12 can be bonded to each other. Structure. This is advantageous for simplifying the structure and manufacturing of the diffraction suppression display screen according to the embodiment of the present invention.
  • optical length equivalent to the distance d can also be realized by adjusting the relevant layers in the display screen 11, for example, by designing the thickness of the substrate on the side of the display screen 11 opposite to the display surface 11a.
  • Fig. 4 schematically shows an example of a periodic structure of pixels in a transparent display screen.
  • the display screen 11 includes periodically arranged pixel units 111 and a light shielding band 112 arranged around the pixel units 111.
  • the light-shielding band 112 may include, for example, a plurality of light-shielding bands along two different directions crossing each other (preferably perpendicular).
  • the light-shielding band 112 is formed of, for example, metal gate lines, such as data lines or address lines.
  • FIG. 5 shows a phase modulation distribution diagram of the diffraction suppression optical component 12A, which essentially corresponds to the transmittance function t 2 (x 2 , y 2 ) of the diffraction suppression optical component 12A.
  • the gray scale at each position (x 2 , y 2 ) in the phase modulation distribution diagram shown in Figure 5 indicates the magnitude of the phase modulation at that position (Expressed in radians).
  • FIG. 6 shows the MTF curve obtained by combining the diffraction suppression optical component 12A (referred to as “inverted phase plate” in the figure) shown in FIG. 5 and the transparent display screen 11 (referred to as “screen” in the figure) shown in FIG.
  • FIG. 6 also shows the MTF curve of the imaging system when there is only the display screen 11 for comparison.
  • the MTF of the system is improved.
  • FIG. 7 shows a simulation data chart of the diffraction suppression effect of the system obtained by combining the diffraction suppression optical component 12A shown in FIG. 5 and the transparent display screen 11 shown in FIG. 4.
  • the arrangement of the diffraction suppression optical component 12A has a significant suppression effect on ⁇ 1 to ⁇ 3 orders, and has a small suppression effect on most orders above ⁇ 4.
  • the transmittance function of the diffraction suppression optical component 12B expressed in Fig. 8 It is calculated according to the design method 3 of the embodiment of the present invention.
  • FIG. 9 shows the MTF curve obtained by combining the diffraction suppressing optical component 12B (referred to as “inverted phase plate” in the figure) shown in FIG. 8 and the transparent display screen 11 (referred to as “screen” in the figure) shown in FIG. Fig. 9 also shows the MTF curve of the imaging system when there is only the display screen 11. As shown in FIG. 9, by adding the diffraction suppression optical component 12B at 1.5 mm, the MTF of the system is improved.
  • FIG. 10 shows a simulation data chart of the diffraction suppression effect of the system obtained by combining the diffraction suppression optical component 12B shown in FIG. 8 and the transparent display screen 11 shown in FIG. 4.
  • the arrangement of the diffraction suppression optical component 12B has a significant suppression effect on ⁇ 1 to ⁇ 3 orders, and has a small suppression effect on most orders above ⁇ 4.
  • the diffraction suppression optical component 12A and the diffraction suppression optical component 12B Comparing the diffraction suppression optical component 12A and the diffraction suppression optical component 12B, the overall diffraction suppression effect and MTF improvement effect brought by the two are similar. Therefore, the easy-to-assemble distance d and the corresponding design of the diffraction suppression optical component 12 can be selected in the design.
  • FIG. 11 is a schematic diagram of an under-screen camera device 1'according to the second embodiment of the present invention.
  • the under-screen imaging device 1 ′ may further include another diffraction suppression optical component 13.
  • the transparent display screen 11, the diffraction suppression optical component 12, and the diffraction suppression optical component 13 constitute the diffraction suppression display screen 10'.
  • the diffraction suppressing optical member 12 is referred to as a first diffraction suppressing optical member
  • the diffraction suppressing optical member 13 is referred to as a second diffraction suppressing optical member for distinction.
  • the second diffraction suppression optical component 13 is an optical component that modulates the amplitude of incident light to suppress diffraction, and has a small influence on the phase of the incident light, and is hereinafter referred to as an amplitude-type diffraction suppression optical component.
  • the second diffraction suppression optical component 13 may be provided between the display screen 11 and the first diffraction suppression optical component 12. In other examples, the second diffraction suppression optical component 13 may also be integrated inside the display screen 11.
  • FIG. 12 shows an example of an amplitude-type diffraction suppressing optical member that can be used in the present invention, the second diffraction suppressing optical member 13A.
  • the second diffraction suppression optical member 13A includes a sheet-shaped body including a first area 131 periodically arranged, and a second area 132 that is arranged around the first area 131 in a substantially strip shape.
  • a transition area 133 located at the edge of the second area 132, wherein the transition area 133 extends from the edge position of the second area 132 to the first area 131 along the normal direction of the edge.
  • the first area 131 is a light-transmitting area
  • the second area 132 includes an opaque area at least at the edge position
  • the transmittance of the transition area 133 changes in its extending direction.
  • the second diffraction suppression optical component 13 is arranged in the diffraction suppression display screen 10' so that the opaque area at the edge of the second area 132 and the first area 131 are respectively connected to the adjacent pixel unit 111 of the light shielding band 112 of the display screen 11.
  • the edge and the corresponding pixel unit 111 correspond to each other.
  • the change in the transmittance of the transition region 133 of the second diffraction suppression optical component 13A in the extending direction conforms to the apodization function, and the apodization function is selected from one of a linear function, a Blackman function, a Connes function, and a Gaussian function.
  • the second diffraction suppression optical component 13A is designed such that the change in the transmittance of the transition region in the extending direction conforms to the Connes function
  • a is the width of the transition area/gray-scale area
  • x is the coordinate value along the direction of the gray-scale change.
  • the transition area 133 of the second diffraction suppression optical member 13A may include an opaque portion and a transparent portion, so that the transmittance of the transition area 133 is determined by the ratio between the opaque portion and the transparent portion.
  • FIGS. 13 and 14 respectively show schematic diagrams of gray cells with different transmittances in the transition region of the second diffraction suppression optical component 13 in FIG. 12.
  • FIG. 13 is a schematic diagram of a gray unit with a square shape and a transparency of 0
  • FIG. 14 is a schematic diagram of a gray unit with a square shape and a certain transparency.
  • 5*5 minimum processing sizes can be used as the transmittance of a gray-scale unit.
  • the gray-scale unit The transmittance of 13a is 0%, and the corresponding gray value is 0; and in the gray unit 13b shown in Figure 14, 5 of the 25 minimum processing sizes are randomly selected to make it transparent, then the gray unit The transmittance of 13b is 20%, and the corresponding gray value is 51.
  • the gray scale of each gray scale unit can be quantized from 0 to 255.
  • the minimum processing size may be 200*200nm.
  • the size of the gray scale cells 13a and 13b in FIG. 13 and FIG. 14 is 1*1um.
  • the gray scale gradation implementation described above is based on the example of 5*5 minimum processing sizes forming a gray unit. Of course, other minimum processing size combinations of different numbers can also be used, such as 4*4, 6*6, 10*10 Wait. In other examples, the gray scale unit may also have a shape other than a square, such as a rectangle, a hexagon, etc., and the present invention is not limited in this respect.
  • the transmittance function of the diffraction suppression optical component 12C expressed in Fig. 15 It is calculated according to the design method 3 of the embodiment of the present invention.
  • the phase effect when the incident light passes through the second diffraction suppression optical component can also be taken into consideration.
  • FIG. 16 shows the diffraction suppression optical member 12C shown in FIG. 15 (referred to as the "inverted phase plate” in the figure) and the transparent display 11 shown in FIG.
  • the MTF curve when only the display screen 11 is combined with the second diffraction suppression optical component 13A is also shown in FIG. 16 for comparison.
  • FIG. 16 by adding the diffraction suppressing optical member 12C at 1 mm, the MTF of the system is also improved compared to the case where the second diffraction suppressing optical member 13A is combined.
  • FIG. 17 shows a simulation data chart of the diffraction suppression effect of the system obtained by combining the diffraction suppression optical component 12C shown in FIG. 15 with the transparent display screen 11 shown in FIG. 4 and the second diffraction suppression optical component 13A shown in FIG. 12.
  • the arrangement of the diffraction suppression optical component 12C has a significant inhibitory effect on orders above ⁇ 2. When the order is above ⁇ 11, it can be suppressed to less than 7% of the original, and the order can be above ⁇ 18. Suppress the original 3% or less.
  • Fig. 18 shows another example of an amplitude-type diffraction suppressing optical member that can be used in the under-screen imaging device 1'shown in Fig. 11, the second diffraction suppressing optical member 13B.
  • the second diffraction suppression optical member 13B is formed as a sheet-like member including a first region 131' periodically arranged in two dimensions and a substantially stripe arranged around the first region 131' Shaped second area 132'.
  • the first area 131' is a light-transmitting area.
  • the second region 132' has a shape generated by randomly displacing a plurality of unit patterns arranged along the extending direction of the strip shape in the lateral direction perpendicular to the extending direction, and the second region 132' is on at least two sides thereof
  • the rim is opaque.
  • the unit pattern is rectangular or line segment shape, and the second area 132' has a random burr shape at its edge as a whole.
  • amplitude-type diffraction suppressing optical member (second diffraction suppressing optical member) that can be used in the present invention is not limited to the specific form described with reference to FIGS. 12 and 18, but may have the ability to amplitude modulate light and thereby suppress display. Any other suitable configuration for diffraction caused by periodic structures in the screen.
  • the phase-type diffraction suppression optical component in the under-screen imaging device is disposed between the display screen and the imaging lens.
  • the phase-type diffraction suppression optical component 12' may be disposed between the imaging lens 21 and the image sensor 22 (see FIG.
  • the under-screen camera device 1" shown in 19) can also be arranged between multiple lenses in the imaging lens 21' (see the under-screen camera device 1"' shown in Fig. 20).

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Abstract

一种用于透明显示屏（11）的相位型衍射抑制光学部件（12）的设计方法，其包括：获取一平面波透过透明显示屏（11）之后在与屏相距距离d的平面上的光场复振幅分布U(x2, y2, d)=A(x2, y2, d)exp(iφ20(x2, y2, d))；和设计衍射抑制光学部件（12），使得其具有透过率函数t2(x2, y2)=exp(iφ21(x2, y2 ))且满足φ20(x2, y2, d)φ21(x2, y2 )=C，C为常数。衍射抑制光学部件（12）和具有其的屏下摄像装置（1）。相位型衍射抑制光学部件（12）通过提供相位调制，抑制屏下摄像装置（1）中的衍射效应，提高了屏下成像的质量。

Description

衍射抑制光学部件设计方法、显示屏和屏下摄像装置
本申请要求享有于2020年2月27日提交中国专利局、申请号为202010124247.X、发明名称为“衍射抑制光学部件设计方法、显示屏和屏下摄像装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明总体上涉及屏下摄像技术，特别是涉及可用于改善屏下摄像成像质量的衍射抑制光学部件的设计方法、衍射抑制显示屏和屏下摄像装置。
背景技术
拍照与显示当前已经成为智能手机的必备功能，而智能手机的前置摄像头更是十分重要。因为前置摄像头不仅能满足自拍需求，而且在人脸识别、内容交互方面也有较大的用途。因此，前置摄像头在手机中已经变得不可或缺。
与此同时，随着智能手机的功能性的提升，大屏幕手机更符合市场趋势。由于屏幕不能无限扩大，使得对高屏占比手机需求也较为旺盛，全面屏则顺势而生，但是由于前置摄像头的原因，完全的全面屏一直无法很好地实现。
为了解决前置摄像头影响全面屏实现的问题，目前已有技术提出将前置摄像头放置于屏幕下面来实现对前置摄像头的完全隐藏，从而完全实现全面屏。但是由于显示屏的存在，对屏下摄像头的拍摄效果有较大的影响。特别是，周期性排列的单元像素会在强光照射下形成由于衍射效应造成的星芒效应，从而影响成像质量。
因此，需要新的屏下摄像技术来抑制衍射造成的星芒效应，从而提高屏下摄像的成像质量。
发明内容
本发明的目的是提供一种衍射抑制光学部件、衍射抑制显示屏和屏下摄像装置，其可用于抑制屏下摄像装置中的衍射，从而改善成像质量。
根据本发明的一个方面，提供了一种用于透明显示屏的衍射抑制光学部件的设计方法，其包括：
(a)获取透明显示屏的透过率函数t 1(x 1,y 1)；
(b)基于所述透过率函数t 1(x 1,y 1)，计算一平面波
Figure PCTCN2021077458-appb-000001
入射所述透明显示屏并透射之后在与所述透明显示屏相距距离d的平面上的光场复振幅分布
Figure PCTCN2021077458-appb-000002
和
(c)设计所述衍射抑制光学部件，使得其具有透过率函数
Figure PCTCN2021077458-appb-000003
Figure PCTCN2021077458-appb-000004
且满足
Figure PCTCN2021077458-appb-000005
C为常数。
在一些有利的实施例中，所述设计方法还可以包括：
(d)改变所述距离d的值，重复上述步骤(b)和(c)；和
(e)对应于不同的距离d，基于所述透明显示屏的透过率函数t 1(x 1,y 1)和所述衍射抑制光学部件的透过率函数t 2(x 2,y 2)，仿真计算包含所述透明显示屏和衍射抑制光学部件的光学系统的衍射抑制效果或调制传递函数，并且比较所述衍射抑制效果或调制传递函数，选定所述距离d的值以及对应的所述衍射抑制光学部件的透过率函数t 2(x 2,y 2)。
优选，在0.1～5mm的范围内改变所述距离d的值，更优选在0.3～2mm的范围内改变所述距离d的值。
在一些实施例中，所述衍射抑制光学部件可以为衍射光学元件，该衍射光学元件包括衬底层和浮雕层，并且所述设计方法还包括：根据所述透过率函数t 2(x 2,y 2)确定所述衍射光学元件的浮雕层的结构以及/或者根据所述距离d确定所述衍射光学元件的衬底层的材料折射率和厚度。
在一些实施例中，所述步骤(a)可以包括：基于所述透明显示屏的层结构的光学参数和几何参数，计算所述透过率函数t 1(x 1,y 1)。
根据本发明的另一个方面，还提供一种衍射抑制显示屏，其包括：显示屏，其允许光从其中透过并包括周期性布置的像素单元；和第一衍射抑制光学部件，其设置在距离所述显示屏一距离d的位置处，其中，所述显示屏具有第一透过率函数t 1(x 1,y 1)，使得当一平面波
Figure PCTCN2021077458-appb-000006
入射所述显示屏并透射后传播所述距离d得到的光场复振幅分布为
Figure PCTCN2021077458-appb-000007
所述衍射抑制光学部件具有第二透过率函数
Figure PCTCN2021077458-appb-000008
并且满足
Figure PCTCN2021077458-appb-000009
Figure PCTCN2021077458-appb-000010
C为常数。
优选距离d在0.1～5mm的范围内，更优选在0.3～2mm的范围内。
所述显示屏还可以包括围绕着像素单元周期性布置的遮光带，并且所述衍射抑制显示屏还包括第二衍射抑制光学部件，所述第二衍射抑制光学部件构造为具有第三透过率函数t 3(x 3,y 3)＝A 3(x 3,y 3)，从而改变对应于所述遮光带边缘附近的位置上的光透过率。所述第二衍射抑制光学部件可以结合在所述显示屏内部或者设置在所述显示屏与第一衍射抑制光学部件之间。
在一些实施例中，所述第二衍射抑制光学部件包括片状主体，该片状主体包括：呈周期性布置的第一区域；围绕着所述第一区域布置的大致呈条带形状的第二区域；和过渡区域，位于所述第二区域的边缘。所述过渡区域从所述第二区域的边缘位置处沿所述边缘的法向朝向所述第一区域延伸，所述第一区域为透光区域，所述第二区域至少在边缘位置处包括不透光区域，所述过渡区域的透过率在其延伸方向上变化。所述第二衍射抑制光学部件的在第二区域的边缘处的不透明区域和第一区域分别与所述显示屏遮光带的邻接像素单元的边缘和相应的像素单元相互对应。
优选，所述第二衍射抑制光学部件的过渡区域的透过率在其延伸方向上的变化符合切趾函数，所述切趾函数选自线性函数、Blackman函数、Connes函数和Gaussian函数中的一个。
在一些实施例中，所述第二衍射抑制光学部件的过渡区域包括不透明部分和透明部分，所述过渡区域的透过率由所述不透明部分和所述透明部分之间的比例决定。
在一些实施例中，所述第二衍射抑制光学部件形成为片状件，该片状件包括呈二维周期性布置的第一区域和围绕着第一区域布置的大致呈条带形状的第二区域，所述第一区域为透光区域，其中，所述第二区域具有由沿着所述条带形状的延伸方向排列的多个单元图形在垂直于所述延伸方向的横向方向上发生随机错位而产生的形状，并且所述第二区域至少在其两个侧缘部分上是不透光的。
根据本发明的又一个方面，提供了一种屏下摄像装置，其包括：如上所述的衍射抑制显示屏，该衍射抑制显示屏具有用于显示的显示表面和与该显示表面相反的背面；和摄像头，其设置于所述衍射显示屏的背面一侧，用于对位于所述衍射显示屏的显示表面一侧的对象进行成像。
根据本发明，相位型衍射抑制光学部件通过提供相位调制，从而抑制屏下装置中的衍射效应，提高了屏下摄像的成像质量。
附图说明
通过阅读参照以下附图所作的对非限制性实施例的详细描述，本发明的其它特征、目的和优点将会变得更明显：
图1示意性地示出结合有根据本发明实施例的屏下摄像装置的电子装置的一个示例；
图2为根据本发明实施方式一的屏下摄像装置的示意图；
图3为根据本发明实施例的衍射抑制光学部件的设计方法的一个示例的示意性流程图；
图4示意性地示出了透明显示屏中像素周期性结构的一个示例；
图5示意性地示出了根据本发明实施例的相位型衍射抑制光学部件的一个示例的相位调制分布图；
图6示出了图5所示相位型衍射抑制光学部件与透明显示屏结合得到的MTF曲线；
图7示出了图5所示相位型衍射抑制光学部件与透明显示屏结合得到的衍射抑制效果的仿真数据图表；
图8示意性地示出了根据本发明实施例的相位型衍射抑制光学部 件的另一示例的相位调制分布图；
图9示出了图8所示相位型衍射抑制光学部件与透明显示屏结合得到的MTF曲线；
图10示出了图8所示相位型衍射抑制光学部件与透明显示屏结合得到的衍射抑制效果的仿真数据图表；
图11为根据本发明实施方式二的屏下摄像装置的示意图；
图12为可用于本发明的振幅型衍射抑制光学部件的一个示例的示意图；
图13示出了图12所示振幅型衍射抑制光学部件的过渡区中不透明的灰度单元的示意图；
图14示出了图12所示振幅型衍射抑制光学部件的过渡区中具有一定透明度的灰度单元的示意图；
图15示意性地示出了根据本发明实施例的相位型衍射抑制光学部件的另一示例的相位调制分布图；
图16示出了图12所示振幅型衍射抑制光学部件、图15所示相位型衍射抑制光学部件与透明显示屏结合得到的MTF曲线；
图17示出了图12所示振幅型衍射抑制光学部件、图15所示相位型衍射抑制光学部件与透明显示屏结合得到的衍射抑制效果的仿真数据图表；
图18为可用于本发明的振幅型衍射抑制光学部件的另一个示例的示意图；
图19为根据本发明实施方式三的屏下摄像装置的示意图；以及
图20为根据本发明实施方式四的屏下摄像装置的示意图。
具体实施方式
下面结合附图和实施例对本发明作进一步的详细说明。可以理解的是，此处所描述的具体实施例仅仅用于解释相关发明，而非对该发明的限定。另外还需要说明的是，为了便于描述，附图中仅示出了与发明相关的部分。
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例 中的特征可以相互组合。下面将参考附图并结合实施例来详细说明本发明。
图1示意性地示出结合有根据本发明实施例的屏下摄像装置1的电子装置的一个示例，智能手机2。在图示示例中，智能手机2可以具有全面屏，屏下摄像装置1可以构造在全面屏的至少部分区域之下。
图2为根据本发明实施方式一的屏下摄像装置1的示意图。如图2所示，屏下摄像装置1包括根据本发明实施例的衍射抑制显示屏10和摄像头20。衍射抑制显示屏10包括透明显示屏11和衍射抑制光学部件12。透明显示屏11允许光从其中透过，并具有用于显示的显示表面11a。衍射抑制光学部件12设置在显示屏11的一侧，优选图2所示设置在显示屏11的与显示表面11a相反的背面一侧。根据本发明实施例，衍射抑制光学部件12为通过对入射光进行相位调制而抑制衍射的光学部件，其对入射光的振幅的影响较小，以下称为相位型衍射抑制光学部件。显示表面11a同时也构成为衍射抑制显示屏10的显示表面。摄像头20设置在衍射抑制显示屏10的与显示表面11a相反的一侧，用于接收透过显示屏11和衍射抑制光学部件12的光并进行成像。如图2所示，摄像头20例如包括成像镜头21和图像传感器22。
由于显示屏11的内部结构，特别是周期性布置的像素单元，对透过显示屏11的光会产生衍射作用，所以摄像头20的成像质量受到影响，特别是会产生星芒效应，此外整个光学系统的调制传递函数(MTF,Modulation Transfer Function)也会下降。为此，根据本发明实施例，增加了相位型衍射抑制光学部件12，其设置在距离显示屏11一距离d的位置处。假设显示屏11具有第一透过率函数t 1(x 1,y 1)，使得当一平面波
Figure PCTCN2021077458-appb-000011
入射显示屏11并透射后传播距离d得到的光场复振幅分布为
Figure PCTCN2021077458-appb-000012
则衍射抑制光学部件12具有的第二透过率函数
Figure PCTCN2021077458-appb-000013
满足
Figure PCTCN2021077458-appb-000014
Figure PCTCN2021077458-appb-000015
C为常数。
距离d优选设置在0.1～5mm的范围内，在一些示例中，更优选设置在0.3～2mm的范围内。
在一些优选实施例中，衍射抑制光学部件12为衍射光学元件 (DOE,Diffractive Optical Element)。
图3为根据本发明实施例的衍射抑制光学部件12的设计方法的一个示例的示意性流程图。如图3所示，衍射抑制光学部件12的设计方法3包括：
S3a：获取透明显示屏11的透过率函数t 1(x 1,y 1)；
S3b：基于透明显示屏11的透过率函数t 1(x 1,y 1)，计算一平面波
Figure PCTCN2021077458-appb-000016
透过透明显示屏之后在与透明显示屏相距距离d的平面上的光场复振幅分布
Figure PCTCN2021077458-appb-000017
S3c：设计衍射抑制光学部件12，使得其具有透过率函数
Figure PCTCN2021077458-appb-000018
Figure PCTCN2021077458-appb-000019
且满足
Figure PCTCN2021077458-appb-000020
C为常数。
根据本发明不同实施例，步骤S3a中，透明显示屏11的透过率函数t 1(x 1,y 1)可以是通过利用已知的光场照射显示屏11并测量透过显示屏11的光场而测量得到，也可以基于透明显示屏的层结构的光学参数和几何参数计算得到。
步骤S3b中，可以基于平面波
Figure PCTCN2021077458-appb-000021
垂直入射显示屏11而计算光场复振幅分布U(x 2,y 2,d)；也可以例如基于平面波非垂直入射或者以不同的多个角度入射下的光场。
步骤S3c中，由于如以上已经介绍的，根据本发明实施例的衍射抑制光学部件12为相位型衍射抑制光学部件，所以假设其具有透过率函数
Figure PCTCN2021077458-appb-000022
(对光的振幅没有影响)，并设计该透过率函数使之满足
Figure PCTCN2021077458-appb-000023
C为常数。例如，C＝0。这样意味着，平面波
Figure PCTCN2021077458-appb-000024
透过透明显示屏11和衍射抑制光学部件12之后得到的波阵面仍旧保持是平面，对显示屏11带来的衍射效果实现了抑制作用。
如图3所示，根据本发明实施例的衍射抑制光学部件设计方法3还可以包括：
S3d：改变距离d的值，重复上述步骤S3b和步骤S3c；和
S3e：对应于不同的距离d，基于透明显示屏的透过率函数t 1(x 1,y 1)和衍射抑制光学部件的透过率函数t 2(x 2,y 2)，仿真计算包含透明显示屏和衍射抑制光学部件的光学系统的衍射抑制效果或调制传递函数， 并且比较所述衍射抑制效果或调制传递函数，以选定距离d的值以及对应的衍射抑制光学部件的透过率函数t 2(x 2,y 2)。
在一些实施例中，优选在一定范围内调整距离d的值，重复步骤S3b和步骤S3c，并计算和比较不同距离d值下包含显示屏11和衍射抑制光学部件12的光学系统所体现出来的衍射抑制效果或调制传递函数，从而选定对应于相对更好衍射抑制效果或调制传递函数的衍射抑制光学部件12透过率函数t 2(x 2,y 2)。
优选在0.1～5mm的范围内改变距离d的值，更优选在0.3～2mm的范围内改变距离d的值。衍射抑制光学部件的设计可以基于矢量衍射理论或者标量衍射理论来进行，但由于矢量衍射理论推导过程复杂，计算量巨大，所以一般来说更倾向于使用标量衍射理论来进行近似计算。然而发明人通过仿真发现当距离d过小时，即小于0.1mm时，使用标量衍射理论来进行近似计算会严重偏离实际情况，导致根据标量衍射理论计算设计得到的相位型衍射抑制光学部件无法达到预期的技术效果。另外，由于本发明所涉及的屏下摄像装置主要应用于便携式通讯设备中，如智能手机、平板电脑等，这些设备通常较薄，因此距离d也不宜过大。
根据本发明的优选实施例，衍射抑制光学部件12为衍射光学元件并且包括衬底层和浮雕层。在这些实施例中，如图3中进一步所示的，衍射抑制光学部件设计方法3还可以包括：
S3f：根据所述透过率函数t 2(x 2,y 2)确定衍射光学元件的浮雕层的结构以及/或者根据距离d确定衍射光学元件的衬底层的材料折射率和厚度。
由于包含显示屏11与衍射抑制光学部件12的光学系统的衍射抑制效果和调制传递函数对于两者之间的距离d是较为敏感的，而严格控制显示屏11与衍射抑制光学部件12之间的距离d并不容易，所以如果通过设计衍射抑制光学部件12的例如衬底层来实现与距离d(空气中)等效的光程，则可以得到例如显示屏11与衍射抑制光学部件12彼此贴合的结构。这对于简化根据本发明实施例的衍射抑制显示屏的结构和制造而言，都是有利的。
应该理解的是，上述与距离d等效的光程也可以通过调节显示屏11中的相关层来实现，例如通过设计显示屏11的与显示表面11a相反一侧的基板厚度。
以下将参照图4至图11介绍衍射抑制光学部件12的两个示例。
图4示意性地示出了透明显示屏中像素周期性结构的一个示例。如图4所示，显示屏11包括周期性布置的像素单元111和围绕着像素单元111布置的遮光带112。遮光带112可以包括例如沿相互交叉(优选垂直)的两个不同方向的多个遮光带。遮光带112例如由金属栅线构成，例如数据线或寻址线。
仅为示例目的而非限制性的，图4所示显示屏11中，像素单元在彼此垂直的两个方向上的排列周期P 1＝P 2＝100μm，像素单元的透光区域在这两个方向上的宽度T 1＝T 2＝80μm，即遮光带的宽度为20μm。
以下介绍的衍射抑制光学部件的示例均针对图4所示显示屏11设计，并且所给出的仿真计算基于屏下摄像装置中的摄像头20为焦距为3.85mm、孔径φ＝1.925mm的理想镜头，波长为532nm等相同参数条件。
图5示出了根据本发明实施例的、针对图4所示显示屏11在距离d＝0.5mm的条件下设计的衍射抑制光学部件12的一个示例，衍射抑制光学部件12A。具体而言，图5示出了衍射抑制光学部件12A的相位调制分布图，其本质对应于衍射抑制光学部件12A的透过率函数t 2(x 2,y 2)。图5所示相位调制分布图中各个位置(x 2,y 2)上的灰度表示了该位置上的相位调制的大小
Figure PCTCN2021077458-appb-000025
(以弧度值表示)。灰度与弧度值的对应关系参见图5中右侧标度。图5所表达的衍射抑制光学部件12A的透过率函数
Figure PCTCN2021077458-appb-000026
是根据本发明实施例的设计方法3计算得到的。
图6示出了图5所示衍射抑制光学部件12A(图中称为“反相相位板”)与图4所示透明显示屏11(图中称为“屏幕”)结合得到的MTF曲线。实际上图6中还给出了仅有显示屏11时成像系统的MTF曲线，以作为对比。如图6所示，通过在0.5mm处增加衍射抑制光学部件12A，提升了系统的MTF。
图7示出了图5所示衍射抑制光学部件12A与图4所示透明显示屏11结合得到的系统的衍射抑制效果的仿真数据图表。如图7所示，衍射抑制光学部件12A的设置，对±1到±3级次有明显的抑制作用，对±4以上的绝大部分级次都有小幅抑制效果。
图8示出了根据本发明实施例的、针对图4所示显示屏11在距离d＝1.5mm的条件下设计的衍射抑制光学部件12的另一示例，衍射抑制光学部件12B。与图5所示类似，图8示出了衍射抑制光学部件12B的相位调制分布图，其本质对应于衍射抑制光学部件12B的透过率函数t 2(x 2,y 2)。图8所表达的衍射抑制光学部件12B的透过率函数
Figure PCTCN2021077458-appb-000027
Figure PCTCN2021077458-appb-000028
是根据本发明实施例的设计方法3计算得到的。
图9示出了图8所示衍射抑制光学部件12B(图中称为“反相相位板”)与图4所示透明显示屏11(图中称为“屏幕”)结合得到的MTF曲线。图9中还给出了仅有显示屏11时成像系统的MTF曲线。如图9所示，通过在1.5mm处增加衍射抑制光学部件12B，提升了系统的MTF。
图10示出了图8所示衍射抑制光学部件12B与图4所示透明显示屏11结合得到的系统的衍射抑制效果的仿真数据图表。如图10所示，衍射抑制光学部件12B的设置，对±1到±3级次有明显的抑制作用，对±4以上的绝大部分级次都有小幅抑制效果。
对比衍射抑制光学部件12A和衍射抑制光学部件12B，两者带来的衍射抑制效果以及MTF提升效果整体相近，因此在设计时可以选择易于装配的距离d以及对应的衍射抑制光学部件12的设计。
图11为根据本发明实施方式二的屏下摄像装置1’的示意图。如图11所示，屏下摄像装置1’还可以包括另一衍射抑制光学部件13。透明显示屏11、衍射抑制光学部件12和衍射抑制光学部件13构成衍射抑制显示屏10’。以下将衍射抑制光学部件12称为第一衍射抑制光学部件，将衍射抑制光学部件13称为第二衍射抑制光学部件，以示区分。根据本发明实施例，第二衍射抑制光学部件13为对入射光进行振幅调制而抑制衍射的光学部件，其对入射光的相位的影响较小，以下称为振幅型衍射抑制光学部件。第二衍射抑制光学部件13具有第三透过率 函数t 3(x 3,y 3)＝A 3(x 3,y 3)，用于改变对应于所述遮光带边缘附近的位置上的光透过率。
图11所示示例中，第二衍射抑制光学部件13可以设置在显示屏11与第一衍射抑制光学部件12之间。在另一些示例中，第二衍射抑制光学部件13也可以结合在显示屏11内部。
图12示出了可用于本发明的振幅型衍射抑制光学部件的一个示例，第二衍射抑制光学部件13A。如图所示，第二衍射抑制光学部件13A包括片状主体，该片状主体包括呈周期性布置的第一区域131、围绕着第一区域131布置的大致呈条带形状的第二区域132、和位于第二区域132的边缘的过渡区域133，其中过渡区域133从第二区域132的边缘位置处沿边缘的法向朝向第一区域131延伸。第一区域131为透光区域，第二区域132至少在边缘位置处包括不透光区域，过渡区域133的透过率在其延伸方向上变化。第二衍射抑制光学部件13在衍射抑制显示屏10’中设置成是的其第二区域132的边缘处的不透明区域和第一区域131分别与显示屏11的遮光带112的邻接像素单元111的边缘和相应的像素单元111相互对应。
第二衍射抑制光学部件13A的过渡区域133的透过率在其延伸方向上的变化符合切趾函数，切趾函数选自线性函数、Blackman函数、Connes函数和Gaussian函数中的一个。图12所示示例中，第二衍射抑制光学部件13A设计成过渡区域透过率在其延伸方向上的变化符合Connes函数
Figure PCTCN2021077458-appb-000029
其中a为过度区域/灰度区域宽度，x为沿灰度变化方向上的坐标值。
第二衍射抑制光学部件13A的过渡区域133可以包括不透明部分和透明部分，从而过渡区域133的透过率由所述不透明部分和所述透明部分之间的比例决定。作为示例，图13和图14分别示出了图12中第二衍射抑制光学部件13的过渡区域中不同透过率的灰度单元的示意图。图13是形状为正方形且透明度为0的灰度单元的示意图，图14是形状为正方形且具有一定透明度的灰度单元的示意图。为了实现过渡区域133的透过率的变化，可以取例如5*5个最小加工尺寸作透过率为一个灰度单元，由于图13所示灰度单元13a中没有透明部分，因此 灰度单元13a的透过率为0％，对应灰度值为0；而图14所示灰度单元13b中，随机取25个最小加工尺寸中的5个最小加工尺寸使其透光，则灰度单元13b的透过率为20％，对应灰度值为51。以此类推，每个灰度单元的灰度可以被量化为0～255。仅作为示例而非限制性的，最小加工尺寸可以为200*200nm。图13和图14中的灰度单元13a和13b的尺寸为1*1um。
以上描述的灰度渐变实现方式是以5*5个最小加工尺寸组成一个灰度单元为例，当然也可以其它不同数量的最小加工尺寸组合方式，例如4*4，6*6，10*10等。在另一些示例中，灰度单元还可以具有正方形以外的形状，例如长方形、六边形等等，本发明在此方面不受限制。
图15示出了根据本发明实施例的、针对图4所示显示屏11在距离d＝1mm的条件下设计的衍射抑制光学部件12的一个示例，衍射抑制光学部件12C。与图5以及图8所示类似，图15示出了衍射抑制光学部件12C的相位调制分布图，其本质对应于衍射抑制光学部件12C的透过率函数t 2(x 2,y 2)。图15所表达的衍射抑制光学部件12C的透过率函数
Figure PCTCN2021077458-appb-000030
是根据本发明实施例的设计方法3计算得到的。在进一步设计衍射抑制光学部件12C时，还可以将入射光通过第二衍射抑制光学部件时的相位影响考虑在内。
图16示出了图15所示衍射抑制光学部件12C(图中称为“反相相位板”)与图4所示透明显示屏11(图中称为“屏幕”)以及图12所示第二衍射抑制光学部件13A(图中称为“灰度掩膜”)结合(第二衍射抑制光学部件13A贴靠在显示屏11上)得到的MTF曲线。图16中还给出了仅显示屏11与第二衍射抑制光学部件13A结合时的MTF曲线，以作为对比。如图16所示，通过在1mm处增加衍射抑制光学部件12C，相对于结合有第二衍射抑制光学部件13A的情况，系统的MTF也得到了提升。
图17示出了图15所示衍射抑制光学部件12C与图4所示透明显示屏11以及图12所示第二衍射抑制光学部件13A结合得到的系统的衍射抑制效果的仿真数据图表。如图17所示，衍射抑制光学部件12C的设置，对±2以上的级次有明显的抑制作用，当级次在±11以上可 抑制到原来的7％以下，级次在±18以上可抑制到原来的3％以下。
图18示出了可用于图11所示屏下摄像装置1’的振幅型衍射抑制光学部件的另一个示例，第二衍射抑制光学部件13B。如图18所示，第二衍射抑制光学部件13B形成为片状件，该片状件包括呈二维周期性布置的第一区域131’和围绕着第一区域131’布置的大致呈条带形状的第二区域132’。第一区域131’为透光区域。第二区域132’具有由沿着条带形状的延伸方向排列的多个单元图形在垂直于延伸方向的横向方向上发生随机错位而产生的形状，并且第二区域132’至少在其两个侧缘部分上是不透光的。图18所示示例中，所述单元图形为长方形或线段形状，第二区域132’整体上在其边缘处具有随机毛刺形状。
应该理解，可用于本发明的振幅型衍射抑制光学部件(第二衍射抑制光学部件)并不限于参照图12和图18所介绍的特定形式，而可以具有能够对光进行振幅调制并从而抑制显示屏中周期性结构引起的衍射的任何其它适合的构造。
以上介绍的本发明实施方式中，屏下摄像装置中相位型衍射抑制光学部件被设置在显示屏和成像镜头之间，这是优选的。但是，根据本发明的发明构思，这样的构造并不是必须的。例如如图19和20分别示出的根据本发明实施方式三和实施方式四的屏下摄像装置中，相位型衍射抑制光学部件12’可以设置在成像镜头21与图像传感器22之间(见图19所示屏下摄像装置1”)，也可以设置在成像镜头21’中的多个镜片之间(见图20所示屏下摄像装置1”’)。
以上描述仅为本申请的较佳实施例以及对所运用技术原理的说明。本领域技术人员应当理解，本申请中所涉及的发明范围，并不限于上述技术特征的特定组合而成的技术方案，同时也应涵盖在不脱离所述发明构思的情况下，由上述技术特征或其等同特征进行任意组合而形成的其它技术方案。例如上述特征与本申请中公开的(但不限于)具有类似功能的技术特征进行互相替换而形成的技术方案。

Claims (15)

  1. 一种用于透明显示屏的衍射抑制光学部件的设计方法，包括：
    (a)获取透明显示屏的透过率函数t 1(x 1,y 1)；
    (b)基于所述透过率函数t 1(x 1,y 1)，计算一平面波
    Figure PCTCN2021077458-appb-100001
    入射所述透明显示屏并透射之后在与所述透明显示屏相距距离d的平面上的光场复振幅分布
    Figure PCTCN2021077458-appb-100002
    和
    (c)设计所述衍射抑制光学部件，使得其具有透过率函数
    Figure PCTCN2021077458-appb-100003
    Figure PCTCN2021077458-appb-100004
    且满足
    Figure PCTCN2021077458-appb-100005
    C为常数。
  2. 如权利要求1所述的设计方法，还包括：
    (d)改变所述距离d的值，重复上述步骤(b)和(c)；和
    (e)对应于不同的距离d，基于所述透明显示屏的透过率函数t 1(x 1,y 1)和所述衍射抑制光学部件的透过率函数t 2(x 2,y 2)，仿真计算包含所述透明显示屏和衍射抑制光学部件的光学系统的衍射抑制效果或调制传递函数，并且比较所述衍射抑制效果或调制传递函数，选定所述距离d的值以及对应的所述衍射抑制光学部件的透过率函数t 2(x 2,y 2)。
  3. 如权利要求2所述的设计方法，其中，在0.1～5mm的范围内改变所述距离d的值，优选在0.3～2mm的范围内改变所述距离d的值。
  4. 如权利要求1或2所述的设计方法，其中，所述衍射抑制光学部件为衍射光学元件，该衍射光学元件包括衬底层和浮雕层，并且所述设计方法还包括：
    根据所述透过率函数t 2(x 2,y 2)，确定所述衍射光学元件的浮雕层的结构。
  5. 如权利要求1或2所述的设计方法，还包括：
    根据所述距离d，确定所述衍射光学元件的衬底层的材料折射率 和厚度。
  6. 如权利要求1所述的设计方法，其中，所述步骤(a)包括：基于所述透明显示屏的层结构的光学参数和几何参数，计算所述透过率函数t 1(x 1,y 1)。
  7. 一种衍射抑制显示屏，包括：
    显示屏，其允许光从其中透过并包括周期性布置的像素单元；和
    第一衍射抑制光学部件，其设置在距离所述显示屏一距离d的位置处，
    其中，所述显示屏具有第一透过率函数t 1(x 1,y 1)，使得当一平面波
    Figure PCTCN2021077458-appb-100006
    入射所述显示屏并透射后传播所述距离d得到的光场复振幅分布为
    Figure PCTCN2021077458-appb-100007
    所述衍射抑制光学部件具有第二透过率函数
    Figure PCTCN2021077458-appb-100008
    并且满足
    Figure PCTCN2021077458-appb-100009
    Figure PCTCN2021077458-appb-100010
    C为常数。
  8. 如权利要求7所述的衍射抑制显示屏，其中，所述距离d在0.1～5mm的范围内，优选在0.3～2mm的范围内。
  9. 如权利要求7所述的衍射抑制显示屏，其中，所述显示屏还包括围绕着像素单元周期性布置的遮光带，并且所述衍射抑制显示屏还包括第二衍射抑制光学部件，所述第二衍射抑制光学部件构造为具有第三透过率函数t 3(x 3,y 3)＝A 3(x 3,y 3)，从而改变对应于所述遮光带边缘附近的位置上的光透过率。
  10. 如权利要求9所述的衍射抑制显示屏，其中，所述第二衍射抑制光学部件结合在所述显示屏内部或者设置在所述显示屏与第一衍射抑制光学部件之间。
  11. 如权利要求9所述的衍射抑制显示屏，其中，所述第二衍射 抑制光学部件包括片状主体，该片状主体包括：
    呈周期性布置的第一区域；
    围绕着所述第一区域布置的大致呈条带形状的第二区域；和
    过渡区域，位于所述第二区域的边缘；
    其中，所述过渡区域从所述第二区域的边缘位置处沿所述边缘的法向朝向所述第一区域延伸，所述第一区域为透光区域，所述第二区域至少在边缘位置处包括不透光区域，所述过渡区域的透过率在其延伸方向上变化，并且
    其中，所述第二衍射抑制光学部件的在第二区域的边缘处的不透明区域和第一区域分别与所述显示屏遮光带的邻接像素单元的边缘和相应的像素单元相互对应。
  12. 如权利要求11所述的衍射抑制显示屏，其中，所述第二衍射抑制光学部件的过渡区域的透过率在其延伸方向上的变化符合切趾函数，所述切趾函数选自线性函数、Blackman函数、Connes函数和Gaussian函数中的一个。
  13. 如权利要求11所述的衍射抑制显示屏，其中，所述第二衍射抑制光学部件的过渡区域包括不透明部分和透明部分，所述过渡区域的透过率由所述不透明部分和所述透明部分之间的比例决定。
  14. 如权利要求9所述的衍射抑制显示屏，其中，所述第二衍射抑制光学部件形成为片状件，该片状件包括呈二维周期性布置的第一区域和围绕着第一区域布置的大致呈条带形状的第二区域，所述第一区域为透光区域，其中，所述第二区域具有由沿着所述条带形状的延伸方向排列的多个单元图形在垂直于所述延伸方向的横向方向上发生随机错位而产生的形状，并且所述第二区域至少在其两个侧缘部分上是不透光的。
  15. 一种屏下摄像装置，包括：
    如权利要求7-14中任一项所述的衍射抑制显示屏，该衍射抑制显示屏具有用于显示的显示表面和与该显示表面相反的背面；和
    摄像头，其设置于所述衍射显示屏的背面一侧，用于对位于所述衍射显示屏的显示表面一侧的对象进行成像。
PCT/CN2021/077458 2020-02-27 2021-02-23 衍射抑制光学部件设计方法、显示屏和屏下摄像装置 WO2021169950A1 (zh)

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Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113053235A (zh) * 2020-02-27 2021-06-29 嘉兴驭光光电科技有限公司 衍射抑制光学部件设计方法、显示屏和屏下摄像装置
CN111953879B (zh) * 2020-08-31 2022-08-09 京东方科技集团股份有限公司 屏下摄像头模组、电子设备及照片拍摄方法
CN113055560B (zh) * 2020-10-19 2023-12-19 上海鲲游科技有限公司 用于实现屏下摄像头的光学系统及其制造方法
TWI837871B (zh) * 2022-10-07 2024-04-01 宏碁股份有限公司 顯示裝置

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101261334A (zh) * 2007-03-07 2008-09-10 富士胶片株式会社 滤光器、以及使用其的液晶显示装置
US9057931B1 (en) * 2012-06-14 2015-06-16 Amazon Technologies, Inc. Display integrated camera
CN106842607A (zh) * 2017-01-19 2017-06-13 浙江工业大学 基于光学衍射元件的激光散斑抑制的实现系统
CN109274789A (zh) * 2018-09-17 2019-01-25 深圳奥比中光科技有限公司 电子设备
CN111402712A (zh) * 2020-02-27 2020-07-10 嘉兴驭光光电科技有限公司 衍射抑制光学部件设计方法、显示屏和屏下摄像装置

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008002692B4 (de) * 2008-06-26 2019-02-21 Seereal Technologies S.A. Displayeinrichtung zur dreidimensionalen holographischen oder stereoskopischen Darstellung räumlicher Objekte und Verfahren zum Ermitteln einer Apodisationsfunktion für eine Apodisationsmaske
US9804088B2 (en) * 2013-12-23 2017-10-31 Robert R. Alfano Spatial frequency spectrometer for and method of detection of spatial structures in materials
DE112017004213A5 (de) * 2016-08-24 2019-05-09 Seereal Technologies S.A. Holographische Anzeigevorrichtung
CN111399156B (zh) * 2018-06-28 2022-10-28 Oppo广东移动通信有限公司 激光投射器、图像获取装置和电子设备
CN110808263B (zh) * 2018-08-06 2020-09-22 云谷（固安）科技有限公司 显示面板、显示屏及显示终端
CN109143607B (zh) * 2018-09-17 2020-09-18 深圳奥比中光科技有限公司 补偿显示屏、屏下光学系统及电子设备
CN109240021B (zh) * 2018-09-17 2020-11-03 深圳奥比中光科技有限公司 屏下光学系统及电子设备
CN109188711B (zh) * 2018-09-17 2020-11-03 深圳奥比中光科技有限公司 屏下光学系统、衍射光学元件的设计方法及电子设备
CN110017969B (zh) * 2019-05-05 2020-04-10 清华大学 透明oled的参数确定方法和装置
KR20210086297A (ko) * 2019-12-31 2021-07-08 엘지디스플레이 주식회사 전자기기
CN111221139B (zh) * 2020-03-23 2022-03-22 Oppo广东移动通信有限公司 聚焦方法和聚焦装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101261334A (zh) * 2007-03-07 2008-09-10 富士胶片株式会社 滤光器、以及使用其的液晶显示装置
US9057931B1 (en) * 2012-06-14 2015-06-16 Amazon Technologies, Inc. Display integrated camera
CN106842607A (zh) * 2017-01-19 2017-06-13 浙江工业大学 基于光学衍射元件的激光散斑抑制的实现系统
CN109274789A (zh) * 2018-09-17 2019-01-25 深圳奥比中光科技有限公司 电子设备
CN111402712A (zh) * 2020-02-27 2020-07-10 嘉兴驭光光电科技有限公司 衍射抑制光学部件设计方法、显示屏和屏下摄像装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4113487A4

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