Optical imaging device

By reasonably arranging lenses and spacers in the optical imaging device and optimizing the light trend, the discrete problems that are prone to occur in the four-piece optical imaging device in the prior art are solved, and the imaging quality and stability are improved.

CN120065461APending Publication Date: 2025-05-30ZHEJIANG SUNNY OPTICAL CO LTD
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Patent Information

Application Number
CN202510402439.5
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2025-03-31
Publication Date
2025-05-30

AI Technical Summary

Technical Problem

The existing four-piece optical imaging device can easily lead to discrete problems when controlling the shape and focal length of the front-end lens, affecting the imaging quality.

Method used

An optical imaging device is designed to optimize the trend and path between the lenses by reasonably arranging the power and surface shape of the four lenses and the position of the spacer to meet the specific radius of curvature and focal length ratio.

Benefits of technology

The concentration of the defocus curve of the optical imaging device is improved, the stability of field curve and imaging quality is improved, and the needs of miniaturization and high imaging quality are met.

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Abstract

The invention provides an optical imaging apparatus. The optical imaging device comprises a lens barrel, a lens group and a spacer group, the lens group and the spacer group are arranged in the lens barrel, the lens group is composed of four lenses, and the four lenses are sequentially a first lens, a second lens, a third lens and a fourth lens from the object side to the image side; the following conditions are satisfied: 0.85 lt; r1 / f1lt; 5.25, 5.25; the formula is as follows:-4.25 lt; f1 / d1slt; and-0.85. According to the invention, the problem that a four-piece optical imaging device in the prior art is easy to cause discretization when controlling the shape and focal length of a front-end lens is solved.
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Claims

1. An optical imaging device, characterized in that: It includes a lens barrel, a lens group and a spacer group disposed in the lens barrel. The lens group consists of four lenses. The four lenses are, in order from the object side to the image side, the first lens, the second lens, the third lens and the fourth lens. The first lens has a negative optical power. The object side surface of the first lens is concave, and the image side surface of the first lens is concave. The second lens has a positive optical power, and the image side surface of the second lens is convex. The third lens has a positive optical power, and the object side surface of the third lens is convex. The object side surface of the fourth lens is concave, and the image side surface of the fourth lens is convex. There is an air gap between two adjacent lenses among the first lens to the fourth lens. The spacer group includes a first spacer disposed between the first lens and the second lens and in partial contact with the image side surface of the first lens. Wherein, the relationship between the curvature radius R1 of the object side surface of the first lens and the effective focal length f1 of the first lens satisfies: 0.85 < R1 / f1 < 5.

25. The relationship between the effective focal length f1 of the first lens and the inner diameter d1s of the object side surface of the first spacer satisfies: -4.25 < f1 / d1s < -0.

85.

2. The optical imaging device according to claim 1, characterized in that: The relationship between the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfies: 0.30 < (R3 + R4) / (R3 - R4) < 2.

75.

3. The optical imaging device according to claim 1, characterized in that: The spacer group further includes a second spacer disposed between the second lens and the third lens and in partial contact with the image side surface of the second lens. The relationship between the air gap T12 between the first lens and the second lens on the optical axis of the optical imaging device and the axial pitch EP12 between the image side surface of the first spacer and the object side surface of the second spacer satisfies: 1.20 < T12 / EP12 < 3.

23.

4. The optical imaging device according to claim 1, characterized in that: The spacer group further includes a second spacer disposed between the second lens and the third lens and in partial contact with the image side surface of the second lens, and a third spacer disposed between the third lens and the fourth lens and in partial contact with the image side surface of the third lens. The relationship between the axial pitch EP23 between the image side surface of the second spacer and the object side surface of the third spacer and the axial distance SAG22 between the intersection point of the image side surface of the second lens and the optical axis of the optical imaging device and the vertex of the effective radius of the image side surface of the second lens satisfies: 1.55 < EP23 / |SAG22| < 3.

22.

5. The optical imaging device according to claim 1, characterized in that: The relationship between the curvature radius R2 of the image side surface of the first lens and the inner diameter d1s of the object side surface of the first spacer satisfies: 0.61 < R2 / d1s < 5.

59.

6. The optical imaging device according to claim 1, characterized in that: The spacer group further includes a second spacer disposed between the second lens and the third lens and in partial contact with the image side surface of the second lens. The relationship between the inner diameter d2m of the image side surface of the second spacer and the effective focal length f3 of the third lens satisfies: 0.45 < d2m / f3 < 0.

75.

7. The optical imaging device according to claim 1, characterized in that: The spacer set further includes a second spacer disposed between the second lens and the third lens and in contact with the image side surface portion of the second lens, The central thickness CT2 of the second lens on the optical axis of the optical imaging device and the axial spacing EP12 between the image side surface of the first spacer and the object side surface of the second spacer satisfy: 0.46 <EP12 / CT2<0.98。 8. The optical imaging device according to claim 1, characterized in that: The effective focal length f2 of the second lens, the inner diameter d1m of the image-side surface of the first spacer, and the outer diameter D1m of the image-side surface of the first spacer satisfy the following: 0.30<(D1m-d1m) / f2<1.

10.

9. The optical imaging device according to claim 1, characterized in that: The spacer set further includes a second spacer disposed between the second lens and the third lens and in contact with the image side surface portion of the second lens, The curvature radius R2 of the image side surface of the first lens, the curvature radius R4 of the image side surface of the second lens, the inner diameter d1s of the object side surface of the first spacer, and the inner diameter d2s of the object side surface of the second spacer satisfy: -2.70 <R4 / d2s×(R2 / d1s)<-0.40。 10. The optical imaging device according to claim 1, characterized in that: The combined focal length f12 of the first lens and the second lens and the axial distance EP01 between the object side end surface of the lens barrel and the object side surface of the first spacer satisfy: 2.26 <f12 / EP01<3.80。