Lens assembly

Abstract

The invention provides a lens assembly, which is suitable for a miniature projection system, and sequentially comprises an aperture, a lens, a first lens and a second lens from an object side to an imaging side, a first lens element with positive refractive power; a second lens element having negative refractive power; a third lens element with positive refractive power; a fourth lens element with positive refractive power; a fifth lens element with negative refractive power; and a display panel.

Description

Technical Field

[0001] The present invention relates to an optical imaging device, and more particularly to a lens assembly used in a projection optics system. Background Art

[0002] In recent years, due to the booming development of augmented reality (AR) applications, as the size of AR electronic devices becomes increasingly miniaturized, the size requirements of projection optics are becoming increasingly stringent. However, the size of projection optics of various manufacturers in the prior art is still relatively large.

[0003] Therefore, how to design a small-sized lens while maintaining high-level imaging quality is an important issue that the industry needs to consider. Summary of the invention

[0004] In view of the above, the present application provides a lens assembly with a compact structure, a small size and an aberration correction effect, thereby solving the problem in the prior art that the lens cannot have both size and imaging quality.

[0005] The present application provides a lens assembly suitable for a micro-projection system, and includes, from the object side to the imaging side, the following components:

[0006] One aperture;

[0007] A first lens having positive refractive power;

[0008] a second lens having negative refractive index;

[0009] a third lens having positive refractive power;

[0010] a fourth lens element having positive refractive power;

[0011] a fifth lens element having negative refractive index; and

[0012] A display panel.

[0013] In one embodiment, the following conditions shown in Formulas 1 to 4 are also satisfied:

[0014] (Formula 1)

[0015] (Formula 2)

[0016] (Formula 3)

[0017] (Formula 4)

[0018] Wherein, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle.

[0019] In one embodiment, the depth of the aspheric surface of each lens is calculated according to the following formula 5:

[0020] (Formula 5)

[0021] Where R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface; Y is the distance between the point on the aspheric curve and the optical axis; K is the conic constant; is the second-order aspheric coefficient.

[0022] The present application also provides a lens assembly suitable for a micro-projection system, and including, from the object side to the imaging side, the following components in order:

[0023] One aperture;

[0024] A first lens having positive refractive power;

[0025] a second lens having negative refractive index;

[0026] A third lens having positive refractive power, wherein both the object side surface and the image side surface of the third lens are convex spherical surfaces;

[0027] a fourth lens element having positive refractive power;

[0028] a fifth lens element having negative refractive index; and

[0029] A display panel.

[0030] In one embodiment, the following conditions shown in Formulas 1 to 4 are also satisfied:

[0031] (Formula 1)

[0032] (Formula 2)

[0033] (Formula 3)

[0034] (Formula 4)

[0035] Wherein, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle.

[0036] In one embodiment, the depth of the aspheric surface of each lens is calculated according to the following formula 5:

[0037] (Formula 5)

[0038] Where R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface; Y is the distance between the point on the aspheric curve and the optical axis; K is the conic constant; is the second-order aspheric coefficient.

[0039] The present application further provides a lens assembly suitable for a micro-projection system, and including, from the object side to the imaging side, the following components in order:

[0040] One aperture;

[0041] A first lens having positive refractive power;

[0042] a second lens having negative refractive index;

[0043] A third lens having positive refractive power, wherein both the object side surface and the image side surface of the third lens are convex spherical surfaces;

[0044] a fourth lens element having positive refractive power;

[0045] a fifth lens element having negative refractive index; and

[0046] a display panel;

[0047] The volume size of the lens assembly is between 0.5 and 5 cubic centimeters.

[0048] In one embodiment, the following conditions shown in Formulas 1 to 4 are also satisfied:

[0049] (Formula 1)

[0050] (Formula 2)

[0051] (Formula 3)

[0052] (Formula 4)

[0053] Wherein, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle.

[0054] In one embodiment, the depth of the aspheric surface of each lens is calculated according to the following formula 5:

[0055] (Formula 5)

[0056] Where R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface; Y is the distance between the point on the aspheric curve and the optical axis; K is the conic constant; is the second-order aspheric coefficient.

[0057] The present application also provides a lens assembly suitable for a micro-projection system, and including, from the object side to the imaging side, the following components in order:

[0058] One aperture;

[0059] A first lens having positive refractive power;

[0060] a second lens having negative refractive index;

[0061] a third lens having positive refractive power, wherein the thickness of the third lens is greater than the thickness of any other lens;

[0062] a fourth lens element having positive refractive power;

[0063] a fifth lens element having negative refractive index; and

[0064] A display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] To make the above and other objects, features, advantages and embodiments of the present invention more understandable, the accompanying drawings are described as follows:

[0066] Figure 1 FIG. 4 is a schematic diagram illustrating a lens assembly according to an embodiment of the present invention.

[0067] Figure 2 for Figure 1 Schematic diagram of one of the lenses of the lens assembly.

[0068] Figure 3 FIG. 4 is a diagram illustrating the lateral aberration of a lens assembly according to an embodiment of the present invention.

[0069] Figure 4 A plurality of aberration diagrams of a lens assembly according to an embodiment of the present invention are shown.

[0070] Figure 5 FIG. 4 is a diagram illustrating the lateral aberration of a lens assembly according to another embodiment of the present invention.

[0071] Figure 6 FIG. 4 is a diagram illustrating aberrations of a lens assembly according to another embodiment of the present invention.

[0072] Figure 7 FIG. 4 is a diagram illustrating the lateral aberration of a lens assembly according to another embodiment of the present invention.

[0073] Figure 8 Schematic diagram showing aberrations of a lens assembly according to another embodiment of the present invention.

[0074] Fig. 9 FIG. 4 is a diagram illustrating the lateral aberration of a lens assembly according to yet another embodiment of the present invention.

[0075] Fig.10 Schematic diagram showing aberrations of a lens assembly according to another embodiment of the present invention.

[0076] According to the usual working method, the various features and components in the figure are not drawn according to the actual scale, and the drawing method is to present the specific features and components related to the present invention in the best way. In addition, the same or similar component symbols are used to refer to similar components and parts between different figures.

[0077] Description of Figure Numbers:

[0078] Lens assembly: 1; aperture: 10; display panel: 20; first lens: 30; second lens: 40; third lens: 50; fourth lens: 60; fifth lens: 70; optical axis: 80; light: 90; lens: 200; optical axis: 201; vertical section: 202; radius of curvature of lens surface: R; distance between a point on the aspheric curve and the optical axis 201: Y; depth of the aspheric surface (vertical section 202 of the aspheric surface from the lens 200): Z. DETAILED DESCRIPTION

[0079] The following embodiments provide different embodiments or examples to establish different features of the provided target. The specific examples of components and arrangements described below are intended to simplify the present disclosure and are not intended to be limiting; the size and shape of the components are not limited by the disclosed ranges or values, but may depend on the process conditions or required characteristics of the components. For example, cross-sectional views are used to describe the technical features of the present invention, and these cross-sectional views are schematic diagrams of idealized embodiments. Therefore, it is foreseeable that the shapes shown in the figures are different due to manufacturing processes and / or tolerances, and should not be limited thereto.

[0080] Furthermore, spatially relative terms, such as "below", "under", "lower than", "above", and "higher than", are intended to facilitate description of the relationship between elements or features shown in the drawings; in addition, spatially relative terms include different directions of components when in use or operation in addition to the directions depicted in the drawings.

[0081] First, please refer to Figure 1 , Figure 1 FIG. 2 is a schematic diagram illustrating a lens assembly according to an embodiment of the present invention. Figure 1 As shown, a lens assembly 1 according to an embodiment of the present invention is suitable for a micro-projection system, and includes, from the object side to the imaging side, an aperture 10, a first lens 30, a second lens 40, a third lens 50, a fourth lens 60, a fifth lens 70, and a display panel 20. The first lens 30 has a positive refractive index; the second lens 40 has a negative refractive index; the third lens 50 has a positive refractive index; the fourth lens 60 has a positive refractive index; and the fifth lens 70 has a negative refractive index. An optical axis 80 is perpendicular to the display panel 20. Light 90 passes through the aperture 10, the first lens 30, the second lens 40, the third lens 50, the fourth lens 60, and the fifth lens 70, and is imaged on the display panel 20.

[0082] In an embodiment of the present invention, the lens assembly 1 satisfies the following conditions shown in Formulas 1 to 4:

[0083] (Formula 1)

[0084] (Formula 2)

[0085] (Formula 3)

[0086] (Formula 4)

[0087] Among them, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle. It should be noted that the first lens is the most important lens for correcting spherical aberration, and the fifth lens is the most important lens for correcting astigmatism and distortion, so the above formulas 1 to 4 only use the focal lengths of the first lens and the fifth lens.

[0088] Next, please refer to Figure 2 , Figure 2 for Figure 1 Schematic diagram of one of the lenses in the lens assembly. Figure 2As shown, in the lens assembly 1 of an embodiment of the present invention, the distance depth of the aspherical surface of any lens 200 is calculated according to the following formula 5:

[0089] (Formula 5)

[0090] Wherein, R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface (the vertical section 202 of the aspheric surface from the lens 200); Y is the distance between a point on the aspheric curve and the optical axis 201; K is the conic constant; is the 2i-th order aspheric coefficient.

[0091] In the lens assembly 1 of the first embodiment of the present invention, the lens information (Lens Data) is shown in Table 1 below. It should be particularly noted that Figure 1 As shown, the side of the first lens 30 facing the aperture 10 is surface 11, and the side facing the display panel 20 is surface 12. The side of the second lens 40 facing the aperture 10 is surface 21, and the side facing the display panel 20 is surface 22. The side of the third lens 50 facing the aperture 10 is surface 31, and the side facing the display panel 20 is surface 32. The side of the fourth lens 60 facing the aperture 10 is surface 41, and the side facing the display panel 20 is surface 42. The side of the fifth lens 70 facing the aperture 10 is surface 51, and the side facing the display panel 20 is surface 52.

[0092]

[0093] In the lens assembly 1 of the first embodiment of the present invention, the aspheric coefficients of each surface are shown in Table 2 below.

[0094]

[0095] Next, please refer to Figure 3 and Figure 4 , Figure 3 A diagram illustrating lateral aberration of a lens assembly according to an embodiment of the present invention; Figure 4 A plurality of aberration diagrams of a lens assembly according to an embodiment of the present invention are shown. It should be particularly noted that: Figure 3 It describes the total aberration effect of the entire optical system. The smaller the value on the vertical axis, the better the optical quality. Figure 4 The smaller the vertical axis value is, the better the correction of spherical aberration, astigmatism and distortion is.

[0096] In addition, in the lens assembly 1 of the second embodiment of the present invention, the lens information (Lens Data) is shown in Table 3 below.

[0097]

[0098] In the lens assembly 1 according to the second embodiment of the present invention, the aspheric coefficients of the surfaces are shown in Table 4 below.

[0099]

[0100] Also, please refer to Figure 5 and Figure 6 , Figure 5 FIG. 4 is a diagram illustrating the lateral aberration of a lens assembly according to another embodiment of the present invention. Figure 6 FIG. 4 is a diagram illustrating aberrations of a lens assembly according to another embodiment of the present invention.

[0101] In addition, in the lens assembly 1 according to the third embodiment of the present invention, the lens information (Lens Data) is shown in Table 5 below.

[0102]

[0103] In the lens assembly 1 according to the third embodiment of the present invention, the aspheric coefficients of the various surfaces are shown in Table 6 below.

[0104]

[0105] Also, please refer to Figure 7 and Figure 8 , Figure 7 A diagram illustrating lateral aberration of a lens assembly according to another embodiment of the present invention; Figure 8 Schematic diagram showing aberrations of a lens assembly according to another embodiment of the present invention.

[0106] In addition, in the lens assembly 1 according to the fourth embodiment of the present invention, the lens information (Lens Data) is shown in Table 7 below.

[0107]

[0108] In the lens assembly 1 according to the fourth embodiment of the present invention, the aspheric coefficients of the surfaces are shown in Table 8 below.

[0109]

[0110] Also, please refer to Fig. 9 and Fig.10 , Fig. 9 A diagram illustrating lateral aberration of a lens assembly according to another embodiment of the present invention; Fig.10 Schematic diagram showing aberrations of a lens assembly according to another embodiment of the present invention.

[0111] Therefore, the present application provides a lens assembly suitable for a micro-projection system, and includes, from the object side to the imaging side, the following components in order:

[0112] One aperture;

[0113] A first lens having positive refractive power;

[0114] a second lens having negative refractive index;

[0115] a third lens having positive refractive power;

[0116] a fourth lens element having positive refractive power;

[0117] a fifth lens element having negative refractive index; and

[0118] A display panel.

[0119] According to one embodiment, the following conditions shown in Formulas 1 to 4 are also satisfied:

[0120] (Formula 1)

[0121] (Formula 2)

[0122] (Formula 3)

[0123] (Formula 4)

[0124] Wherein, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle.

[0125] According to one embodiment, the depth of the aspheric surface of each lens is calculated according to the following formula 5:

[0126] (Formula 5)

[0127] Where R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface; Y is the distance between the point on the aspheric curve and the optical axis; K is the conic constant; is the second-order aspheric coefficient.

[0128] The present application further provides a lens assembly suitable for a micro-projection system, and including, from the object side to the imaging side, the following components in order:

[0129] One aperture;

[0130] A first lens having positive refractive power;

[0131] a second lens having negative refractive index;

[0132] A third lens having positive refractive power, wherein both the object side surface and the image side surface of the third lens are convex spherical surfaces;

[0133] a fourth lens element having positive refractive power;

[0134] a fifth lens element having negative refractive index; and

[0135] A display panel.

[0136] According to one embodiment, the following conditions shown in Formulas 1 to 4 are also satisfied:

[0137] (Formula 1)

[0138] (Formula 2)

[0139] (Formula 3)

[0140] (Formula 4)

[0141] Wherein, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle.

[0142] According to one embodiment, the depth of the aspheric surface of each lens is calculated according to the following formula 5:

[0143] (Formula 5)

[0144] Where R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface; Y is the distance between the point on the aspheric curve and the optical axis; K is the conic constant; is the second-order aspheric coefficient.

[0145] The present application further provides a lens assembly suitable for a micro-projection system, and including, from the object side to the imaging side, the following components in order:

[0146] One aperture;

[0147] A first lens having positive refractive power;

[0148] a second lens having negative refractive index;

[0149] A third lens having positive refractive power, wherein both the object side surface and the image side surface of the third lens are convex spherical surfaces;

[0150] a fourth lens element having positive refractive power;

[0151] a fifth lens element having negative refractive index; and

[0152] a display panel;

[0153] The volume size of the lens assembly is between 0.5 and 5 cubic centimeters.

[0154] According to one embodiment, the following conditions shown in Formulas 1 to 4 are also satisfied:

[0155] (Formula 1)

[0156] (Formula 2)

[0157] (Formula 3)

[0158] (Formula 4)

[0159] Wherein, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle.

[0160] According to one embodiment, the depth of the aspheric surface of each lens is calculated according to the following formula 5:

[0161] (Formula 5)

[0162] Where R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface; Y is the distance between the point on the aspheric curve and the optical axis; K is the conic constant; is the second-order aspheric coefficient.

[0163] The present application also provides a lens assembly suitable for a micro-projection system, and including, from the object side to the imaging side, the following components in order:

[0164] One aperture;

[0165] A first lens having positive refractive power;

[0166] a second lens having negative refractive index;

[0167] a third lens having positive refractive power, wherein the thickness of the third lens is greater than the thickness of any other lens;

[0168] a fourth lens element having positive refractive power;

[0169] a fifth lens element having negative refractive index; and

[0170] A display panel.

[0171] In summary, the lens assembly 1 of the present invention is a compact structure that combines small size with aberration correction effect, thereby solving the problem in the prior art that the lens cannot have both size and imaging quality.

[0172] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A lens assembly, characterized in that: Applicable to micro-projection systems, and including, from the object side to the imaging side: One aperture; A first lens having positive refractive power; a second lens having negative refractive index; a third lens having positive refractive power; a fourth lens element having positive refractive power; a fifth lens element having negative refractive index; and A display panel.

2. The lens assembly according to claim 1, characterized in that: The following conditions 1 to 4 are also satisfied: (Formula 1) (Formula 2) (Formula 3) (Formula 4) Wherein, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle.

3. The lens assembly according to claim 1, characterized in that: The depth of the aspheric surface of each lens is calculated according to the following formula 5: (Formula 5) Where R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface; Y is the distance between the point on the aspheric curve and the optical axis; K is the conic constant; is the second-order aspheric coefficient.

4. A lens assembly, characterized in that: Applicable to micro-projection systems, and including, from the object side to the imaging side: One aperture; A first lens having positive refractive power; a second lens having negative refractive index; A third lens having positive refractive power, wherein both the object side surface and the image side surface of the third lens are convex spherical surfaces; a fourth lens element having positive refractive power; a fifth lens element having negative refractive index; and A display panel.

5. The lens assembly according to claim 4, characterized in that: The following conditions 1 to 4 are also satisfied: (Formula 1) (Formula 2) (Formula 3) (Formula 4) Wherein, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle.

6. The lens assembly according to claim 4, characterized in that: The depth of the aspheric surface of each lens is calculated according to the following formula 5: (Formula 5) Where R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface; Y is the distance between the point on the aspheric curve and the optical axis; K is the conic constant; is the second-order aspheric coefficient.

7. A lens assembly, suitable for a micro-projection system, and comprising, from the object side to the imaging side, the following: One aperture; A first lens having positive refractive power; a second lens having negative refractive index; A third lens having positive refractive power, wherein both the object side surface and the image side surface of the third lens are convex spherical surfaces; a fourth lens element having positive refractive power; a fifth lens element having negative refractive index; and a display panel; The volume size of the lens assembly is between 0.5 and 5 cubic centimeters.

8. The lens assembly according to claim 7, characterized in that: The following conditions 1 to 4 are also satisfied: (Formula 1) (Formula 2) (Formula 3) (Formula 4) Wherein, f is the focal length of the lens assembly, f1 is the focal length of the first lens, f2 is the focal length of the second lens, f3 is the focal length of the third lens, f4 is the focal length of the fourth lens, f5 is the focal length of the fifth lens, TTL is the total length of the lens assembly, and Φ is the image circle.

9. The lens assembly according to claim 7, characterized in that: The depth of the aspheric surface of each lens is calculated according to the following formula 5: (Formula 5) Where R is the radius of curvature of the lens surface; Z is the depth of the aspheric surface; Y is the distance between the point on the aspheric curve and the optical axis; K is the conic constant; is the second-order aspheric coefficient.

10. A lens assembly, suitable for a micro-projection system, and comprising, from the object side to the imaging side, the following: One aperture; A first lens having positive refractive power; a second lens having negative refractive index; a third lens having positive refractive power, wherein the thickness of the third lens is greater than the thickness of any other lens; a fourth lens element having positive refractive power; a fifth lens element having negative refractive index; and A display panel.

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