WO2021097747A1 - Microlens array element and diffuser, and electronic device - Google Patents

Abstract

A microlens array element, a diffuser and an electronic device. The microlens array element comprises: a substrate, a side surface of the substrate being provided with a microlens array composed of a plurality of microlenses, the microlenses being aspheric microlenses, and the curved surfaces of the aspheric microlenses facing away from the substrate being circularly symmetrical curved surfaces. Thus, by reasonably setting parameters of the curved surfaces of the microlenses, the illumination distribution of the microlenses can be more uniform, thereby guaranteeing the imaging quality of an electronic element provided with the microlens array element.

Description

Micro lens array element, diffuser sheet and electronic device Technical field

The invention relates to the field of biological recognition, and in particular to a microlens array element, a diffusion sheet and an electronic device.

Background technique

Currently, the diffuser in time of flight (TOF) generally uses DOE (diffractive optical element) technology and MLA (micro lens array) technology to project light. The DOE technology uses the principle of diffractive optics to diffract the laser light into the target area, but because of the large angle, it is difficult to design and manufacture, and its energy efficiency is low, and there is more stray light around the effective area as a whole. MLA technology can use a closely arranged lens array to refract the light emitted by the light source into the corresponding effective area.

In related technologies, the microlens array not only has the basic functions of traditional lenses such as focusing and imaging, but also has the characteristics of small unit size and high integration, so that it can perform functions that traditional optical elements cannot perform, and can form many new types of optical components. system. The parameters of the microlens array must be designed to meet the range of the field of view, to ensure the uniformity of the illuminance within the field of view, and to maintain a certain brightness at the edge of the field of view. However, the design of the curved shape of some microlenses is not good enough, and the resulting illuminance will show uneven fluctuations.

Summary of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, an object of the present invention is to provide a microlens array element, which is used to solve the problem that the curved appearance of part of the microlens is not good enough, and the resulting illuminance will show uneven fluctuations. .

The invention also provides a diffusion sheet.

The present invention further provides an electronic device.

The microlens array element according to the embodiment of the present invention includes: a substrate, one side surface of the substrate is provided with a microlens array composed of a plurality of microlenses, the microlenses are aspherical microlenses, and the aspherical microlenses The curved surface of the lens away from the substrate is a circularly symmetric curved surface.

Therefore, the microlens array thus arranged can meet the range of the field of view, and can ensure the uniformity of the illuminance within the field of view, and can maintain a certain brightness at the edge of the field of view, so as to ensure that the microlens array element is provided. The imaging quality of electronic components.

In some embodiments of the present invention, the projection of the microlens on the substrate is rectangular, the projection of the microlens on the substrate has a first side and a second side, and the first side The size of the side is a, and the size of the second side is b, where a and b satisfy the relationship: a>b. The rectangular microlenses arranged in this way can have multiple arrangements, and it can be ensured that the light spot emitted by the microlens array under the effective parameter range is a rectangular light spot.

In some embodiments of the present invention, the ratio of the size of the second side to the size of the first side is s, where s satisfies the relationship: 0.65≤s≤0.85. The microlens array element 100 arranged in this way can achieve the effect of accurately distributing light in the effective area.

In some embodiments of the present invention, the microlens array element is characterized in that 0.74≤s≤0.76. When 0.74≤s≤0.76, the rectangular spot closest to the size ratio of the second side and the first side can be obtained, that is, the illuminance distribution is more uniform.

In some embodiments of the present invention, the microlens array element is characterized in that a and b satisfy the relationship: 10 μm≦b<a≦100 μm. This setting can make the illuminance evenly distributed.

In some embodiments of the present invention, the microlens has a central axis, the height of the central axis is d, the height of a line segment that intersects the central axis and the microlens is d, and d satisfies the relationship: 10μm≤d ≤50μm. This setting can effectively ensure the uniformity of the illuminance distribution.

In some embodiments of the present invention, in the microlens array, all the microlenses have the same extending direction of the first side and the same extending direction of the second side. The micro lens array arranged in this way can achieve the effect of precise light distribution in the effective area.

In some embodiments of the present invention, in the microlens array, the adjacent microlenses are arranged in sequence along a first direction, and are arranged staggered along a second direction, wherein the first direction is the first side The extension direction of the second side or the extension direction of the second side, and the second direction is the extension direction of the second side or the extension direction of the first side corresponding to the first direction. The micro lens array arranged in this way can also achieve the effect of precise light distribution in the effective area.

In some embodiments of the present invention, the curve formula of the curved surface is:

Among them, z is the vector height of the optical surface, c is the curvature at the apex of the aspheric surface, k is the coefficient of the aspheric surface, α1, α2, α3, α4, α5, α6, α7, α8 are the coefficients of various orders, and r is the point to micro The distance coordinate of the optical axis of the lens; the parameters satisfy the relationship: α ₁ =0, α ₂ ＞0, α ₃ ＜0, α ₄ ＞0, α ₅ ＜0, α ₆ ＞0, α ₇ ＜0, α ₈ ＞ 0, k<0, r>0. The microlens array arranged in this way can ensure uniform illumination distribution within the field of view.

In some embodiments of the present invention, 3x10 ⁴ ＜α ₂ ＜5x10 ⁴ , -9x10 ⁷ ＜α ₃ ＜-4x10 ⁷ , 5x10 ¹⁰ ＜α ₄ ＜1x10 ¹¹ , -7x10 ¹³ ＜α ₅ ＜-3x10 ¹³ , 1x10 ¹⁶ ＜α ₆ ＜4x10 ¹⁶ , -8x10 ¹⁸ ＜α ₇ ＜-2x10 ¹⁸ , 2x10 ²⁰ ＜α ₈ ＜8x10 ² ,, -12＜k＜-5,0.005＜r＜0.03. The microlens array set in this way meets the curve formula of the curved surface with uniform illuminance distribution and high accuracy.

The diffusion sheet according to the embodiment of the present invention includes a microlens array element. The beneficial effect of the diffuser is the same as that of the microlens array element, and the description will not be repeated here.

The electronic product according to the present invention includes the diffusion sheet. The image quality of the electronic product set in this way is higher.

The additional aspects and advantages of the present invention will be partly given in the following description, and partly will become obvious from the following description, or be understood through the practice of the present invention.

Description of the drawings

The above and/or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

Fig. 1 is a first structural diagram of a microlens array element according to an embodiment of the present invention;

2 is a schematic diagram of the structure of a micro lens according to an embodiment of the present invention;

Figure 3 is a cross-sectional view of a microlens array according to an embodiment of the present invention;

4 is a second structural diagram of a microlens array element according to an embodiment of the present invention;

Fig. 5 is a partial enlarged view of area A in Fig. 4.

Reference signs:

The microlens array element 100; the substrate 10; the microlens array 20; the microlens 30; the first side 31; the second side 32;

Detailed ways

The embodiments of the present invention will be described in detail below. The embodiments described with reference to the drawings are exemplary. The embodiments of the present invention will be described in detail below.

The microlens array element 100 according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

As shown in FIGS. 1 to 5, the microlens array element 100 according to some embodiments of the present invention includes a substrate 10, and a microlens array 20 composed of a plurality of microlenses 30 is provided on one side surface of the substrate 10. The substrate 10 has a certain thickness. A microlens array 20 composed of a plurality of microlenses 30 is provided on one side surface of the substrate 10. The microlens array 20 not only has the basic functions of traditional lenses such as focusing and imaging, but also has the characteristics of small unit size and high integration. The microlens array 20 refracts the light emitted by the light source into the corresponding effective area by using a closely arranged lens array.

The microlens 30 is an aspherical microlens 30, and the aspherical microlens 30 can maintain good aberration correction, and more effectively realize the miniaturization of products, and has been widely used in the fields of optical instruments and optoelectronics industries. In addition, the curved surface of the aspheric microlens 30 away from the substrate 10 is a circularly symmetric curved surface. By setting the curved surface of the micro lens 30 to be a circularly symmetric curved surface, the purpose of accurately controlling the shape of the micro lens 30 can be achieved, so that the purpose of accurately distributing light in the effective area can be achieved. The parameters of the microlens array 20 set in this way can meet the range of the field of view angle during the design, can ensure the uniformity of the illuminance in the field of view, and can maintain a certain brightness at the edge of the field of view, and can ensure the illuminance in the field of view. The distribution is uniform, so that the imaging quality of the electronic device provided with the microlens array element 100 can be ensured.

Specifically, as shown in FIGS. 1 to 4, the projection of the microlens 30 on the substrate 10 may be rectangular. The projection of the microlens 30 on the substrate 10 has a first side 31 and a second side 32, the size of the first side 31 is a, and the size of the second side 32 is b, where a and b satisfy the relationship : A>b. By reasonably setting the shape of the microlens 30, the shape of the microlens 30 can be easily controlled, and the microlens 30 can be arranged in a variety of arrangements on the substrate 10, so that the microlens array 20 can be formed. To achieve the purpose of precise light distribution in the effective area, the light diffused through the microlens array 20 can completely match the effective area, and the illuminance is evenly distributed.

In some embodiments of the present invention, the ratio of the size of the second side 32 to the size of the first side 31 is s, and within a certain range, the microlens array element 100 can achieve desired effects. Among them, s satisfies the relationship: 0.65≤s≤0.85. The microlens array element 100 arranged in this way can achieve the effect of accurately distributing light in the effective area, and the illuminance is evenly distributed.

Optionally, the first side 31 and the second side 32 can be set within a certain range to achieve the desired effect. For example: 0.74≤s≤0.76. The upper end of the micro lens 30 is provided with a curved exit surface. When the ratio of the size of the second side 32 to the size of the first side 31 remains unchanged, the preferred parameter range can be obtained by adjusting the shape of the exit surface of the microlens 30. When 0.74≤s≤0.76, the illuminance distribution can be more uniform. Among them, s=0.75.

Further, a and b may satisfy the relationship: 10 μm≦b<a≦100 μm. When the first side 31 and the second side 32 are within this range, a rectangular spot that is closest to the size ratio of the second side 32 and the first side 31 can be obtained, that is, the illuminance distribution is more uniform.

Specifically, with reference to FIG. 3, the microlens 30 has a central axis 33, the height of the line segment 33 intersecting the central axis with the microlens is d, and d satisfies the relationship: 10 μm≦d≦50 μm. d is the length of the connection line from the highest point of the exit surface of the microlens 30 to the center point of the bottom of the microlens 30. The highest point of the line segment 33 is the vertex of the exit surface. The shortest line from the highest point of the exit surface to any vertex of the lower end of the exit surface is a diagonal line, which is a curve, and is located on the same plane as the exit surface. Optionally, from the highest point of the top surface of the microlens 30 to the center of rotation of the microlens 30, the first side 31, the second side 32 and the diagonal of the microlens 30 have the same curvature surface characteristics. .

According to some embodiments of the present invention, as shown in FIG. 1, in the microlens array 20, the first side 31 of all the microlenses 30 extends in the same direction, and the second side 32 extends in the same direction. In other words, each microlens 30 is sequentially arranged on the substrate 10 of the microlens array element 100 at the same angle. Multiple rows and multiple columns of microlenses 30 may be provided in the microlens array 20. For example, in the example of FIG. 1, the first side 31 of the micro lens 30 is a side extending in the left and right direction, and the second side 32 of the micro lens 30 is a side extending in the front and rear direction. The microlenses 30 sequentially arranged in the left-right direction are in a row, and the microlenses 30 sequentially arranged in the front-rear direction are in a row. The projections of the adjacent second side edges 32 of the two adjacent microlenses 30 in each row on the substrate 10 can be completely overlapped, and the first side edges 31 on the same side of the multiple microlenses 30 in each row The projection of the extension line on the substrate 10 is a straight line. The projections of the adjacent first sides 31 of the two adjacent microlenses 30 in each column on the substrate 10 can be completely overlapped, and the projections of the second sides 32 on the same side of the multiple microlenses 30 in each column The projection of the extension line on the substrate 10 is a straight line. The multiple rows and multiple rows of microlenses 30 arranged in this way can form a microlens array 20. Of course, the present invention is not limited to this, and the embodiment of the present invention may also have multiple arrangements of the microlens array 20.

Of course, in other embodiments of the present invention, referring to FIGS. 4 and 5, in the microlens array 20, adjacent microlenses 30 are arranged in sequence along the first direction, and are arranged staggered along the second direction, wherein, The first direction is the extension direction of the first side 31 or the extension direction of the second side 32, and the second direction is the extension direction of the second side 32 or the extension direction of the first side corresponding to the first direction. For example, in the examples of FIGS. 4 and 5, the first direction is the extending direction of the second side 32. The second direction is the direction in which the first side 31 extends. A plurality of microlenses 30 arranged in sequence in the first direction and staggered in the second direction form a microlens array 20. The microlens array 20 arranged in this way can also achieve the effect of precise light distribution in the effective area.

Further, the curve formula of the curved surface can be:

Among them, z is the vector height of the optical surface, c is the curvature at the apex of the aspheric surface, k is the coefficient of the aspheric surface, α1, α2, α3, α4, α5, α6, α7, α8 are the coefficients of various orders, and r is the point to micro The distance coordinate of the optical axis of the lens; the parameters satisfy the relationship: α ₁ =0, α ₂ ＞0, α ₃ ＜0, α ₄ ＞0, α ₅ ＜0, α ₆ ＞0, α ₇ ＜0, α ₈ ＞ 0, k<0, r>0. The curve formula of the curved surface is the appearance description formula of the optical lens. In the example of the present invention, the appearance description formula can describe any aspheric curve. The microlens array 20 arranged in this way can ensure uniform illuminance distribution in the field of view, thereby effectively improving the imaging quality of the electronic device.

According to some embodiments of the present invention, the microlens array element 100 is characterized by: 3x10 ⁴ ＜α ₂ ＜5x10 ⁴ , -9x10 ⁷ ＜α ₃ ＜-4x10 ⁷ , 5x10 ¹⁰ ＜α ₄ ＜1x10 ¹¹ , -7x10 ¹³ ＜ α ₅ ＜-3x10 ¹³ , 1x10 ¹⁶ ＜α ₆ ＜4x10 ¹⁶ , -8x10 ¹⁸ ＜α ₇ ＜-2x10 ¹⁸ , 2x10 ²⁰ ＜α ₈ ＜8x10 ²⁰ , -12＜k＜-5, 0.005＜r＜0.03. The lens array element 100 provided in this way has a high accuracy, which can satisfy the requirement of precise light distribution in the effective area.

According to an example of the present invention, the parameters of the microlens array element 100 have but are not limited to the characteristics shown in Table 1:

Table 1

The microlens array element 100 manufactured according to the parameters in the above table can accurately distribute light in the effective area.

The diffusion sheet according to the embodiment of the present invention includes the microlens array element 100 according to the above-mentioned embodiment of the present invention.

The electronic device according to the present invention includes the diffusion sheet of the above-mentioned embodiment.

In the description of the present invention, it should be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", " The orientation or positional relationship indicated by "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, and are only for convenience The present invention is described and simplified description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

In the description of the present invention, "plurality" means two or more.

In the description of this specification, descriptions with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean specific features described in conjunction with the embodiment or example , Structure, materials or features are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above-mentioned terms does not necessarily refer to the same embodiment or example.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims (12)

1. A microlens array element, characterized by comprising: a substrate, one side surface of the substrate is provided with a microlens array composed of a plurality of microlenses, the microlenses are aspherical microlenses, and the aspherical microlenses The curved surface of the lens away from the substrate is a circularly symmetric curved surface.
2. The microlens array element according to claim 1, wherein the projection of the microlens on the substrate is rectangular, and the projection of the microlens on the substrate has a first side and a second side connected to each other. Two sides, the size of the first side is a, and the size of the second side is b, where a and b satisfy the relationship: a>b.
3. 3. The microlens array element according to claim 2, wherein the ratio of the size of the second side to the size of the first side is s, where s satisfies the relationship: 0.65≤s≤0.85.
4. The microlens array element according to claim 3, wherein 0.74≤s≤0.76.
5. The microlens array element according to claim 2, wherein a and b satisfy the relational expression: 10 μm≦b<a≦100 μm.
6. The microlens array element according to claim 2, wherein the microlens has a central axis, the height of a line segment intersecting the central axis and the microlens is d, and d satisfies the relationship: 10μm≤d≤50μm .
7. 3. The microlens array element according to claim 2, wherein in the microlens array, all the microlenses have the same extension direction of the first side and the same extension direction of the second side.
8. The microlens array element according to claim 2, wherein in the microlens array, the adjacent microlenses are arranged in sequence along a first direction, and are arranged staggered along a second direction, wherein the first One direction is the extension direction of the first side edge or the extension direction of the second side edge, and the second direction is the extension direction of the second side edge or the extension direction of the first side edge corresponding to the first direction.
9. The microlens array element according to claim 1, wherein the curve formula of the curved surface is:

   

   Among them, z is the vector height of the optical surface, c is the curvature at the apex of the aspheric surface, k is the coefficient of the aspheric surface, α1, α2, α3, α4, α5, α6, α7, α8 are the coefficients of various orders, and r is the point to micro The distance coordinate of the optical axis of the lens; the parameters satisfy the relationship: α ₁ =0, α ₂ ＞0, α ₃ ＜0, α ₄ ＞0, α ₅ ＜0, α ₆ ＞0, α ₇ ＜0, α ₈ ＞ 0, k<0, r>0.
10. The microlens array element according to claim 9, wherein 3x10 ⁴ <α ₂ ＜5x10 ⁴ , -9x10 ⁷ ＜α ₃ ＜-4x10 ⁷ , 5x10 ¹⁰ ＜α ₄ ＜1x10 ¹¹ , -7x10 ¹³ ＜α ₅ ＜-3x10 ¹³ , 1x10 ¹⁶ ＜α ₆ ＜4x10 ¹⁶ , -8x10 ¹⁸ ＜α ₇ ＜-2x10 ¹⁸ , 2x10 ²⁰ ＜α ₈ ＜8x10 ²⁰ , -12＜k＜-5, 0.005＜r＜0.03.
11. A diffusion sheet, characterized by comprising: the microlens array element according to any one of claims 1-10.
12. An electronic device, characterized by comprising the diffusion sheet according to claim 11.

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