A large field of view large zoom ratio digital monocular imaging system

Abstract

The application discloses a large-view-field and large-variation-ratio digital single-cylinder imaging system, which is composed of auxiliary objective optical lens group G1, front group optical lens group G2, zoom group optical lens group G3, compensation group optical lens group G4, rear group optical lens group G5 and auxiliary cylinder optical lens group G6 along the optical axis from the object plane to the image plane. The front group optical lens group G2 and the rear group optical lens group G5 are fixed in position, the zoom optical lens group G3 and the compensation optical lens group G4 can move along the optical axis, the continuous variation of the system magnification is realized by changing the distance between the zoom optical lens group G3 and the front group optical lens group G2, the distance between the zoom optical lens group G3 and the compensation optical lens group G4 and the distance between the compensation optical lens group G4 and the rear group optical lens group G5, and the advantage is that the continuous variation zooming range of 0.44-6.6x can be realized by selecting the optical parameters of each optical lens group and setting each optical lens group at a specific position, and the zooming ratio can reach 1:15; the imaging field diameter can reach phi 16 mm, and a large target surface digital camera or a display screen can be connected.

Description

Technical Field

[0001] This invention relates to a digital monocular imaging system, and more particularly to a digital monocular imaging system with a large field of view and large magnification. Background Technology

[0002] The booming development of the intelligent manufacturing industry has driven the rapid progress of the entire electronics manufacturing industry, including semiconductors, flat panel displays, and printed circuit boards. At the same time, new upgrade requirements have been put forward for the inspection of electronic industrial production lines, the verification of printed circuit boards, the verification of welding defects (printing misalignment, edge collapse, etc.) in printed circuit components, the verification of single-board PCs, and the inspection of vacuum fluorescent displays (VFDs). For example, it is necessary to achieve micron-level detection, high resolution, large field of view clarity, and adaptability to sample detection of different heights and sizes.

[0003] Monocular zoom microscopes are widely used in industrial inspection due to their ease of operation, intuitive visualization, high inspection efficiency, and strong stereoscopic effect. However, current imaging systems in monocular microscopes still suffer from limitations such as small zoom range, insufficient field of view, and low resolution, failing to fully meet the evolving requirements of modern industrial inspection. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a digital monocular imaging system with large zoom ratio, large field of view, low distortion and achromatic performance, which can meet the new upgrade requirements of industrial inspection today.

[0005] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: a large field of view and large zoom ratio digital monocular imaging system, comprising, along its optical axis from the object plane to the image plane, an auxiliary objective lens optical group G1, a front optical group G2, a zoom optical group G3, a compensation optical group G4, a rear optical group G5, and an auxiliary tube lens optical group G6 arranged sequentially. The positions of the front optical group G2 and the rear optical group G5 are fixed, while the zoom optical group G3 and the compensation optical group G4 can move along the optical axis. This is achieved by changing the distance between the zoom optical group G3 and the front optical group G2, between the zoom optical group G3 and the compensation optical group G4, and between the compensation optical group G4 and the rear optical group G5. To achieve continuous magnification variation, the auxiliary objective lens group G1 has a focal length of 95mm, the front optical group G2 has a focal length of 51.7mm, the zoom optical group G3 has a focal length of -30.6mm, the compensation optical group G4 has a focal length of -29.2mm, the rear optical group G5 has a focal length of 52.5mm, and the auxiliary tube lens optical group G6 has a focal length of 172mm. The auxiliary objective lens group G1 sends parallel light rays to the front optical group G2; the rear optical group G5 sends parallel light rays to the auxiliary tube lens optical group G6. The distance between the front optical group G2 and the rear optical group G5 is 78mm, and the system magnification range is 0.44× to 6.6×.

[0006] Compared with existing technologies, the advantages of this invention are that by selecting the optical parameters of each optical lens group and setting them in specific positions, a continuously varying zoom range of 0.44× to 6.6× can be achieved, with a zoom ratio of up to 1:15; the imaging field of view diameter can reach φ16mm, allowing connection to large-format digital cameras or displays to meet the inspection requirements of a wide field of view; the numerical aperture (NA) can reach 0.1, improving resolution, and the system also performs achromatic and distortion correction, resulting in clear and bright images; the working distance of this invention is 95mm, adapting to the inspection needs of samples of different heights and sizes. Therefore, this imaging system fully meets the new upgrade requirements of industrial inspection.

[0007] Preferably, the auxiliary objective lens group G1 is a metallographic optical objective lens group, which can obtain a greater optical magnification.

[0008] The zoom optical lens group G3 and the compensation optical lens group G4 are moved along the optical axis by a cam mechanism.

[0009] Preferably, the auxiliary objective lens optical group G1 has an object plane at its front focal point, and the auxiliary tube lens optical group G6 has a digital camera or CMOS chip at its rear focal point.

[0010] Preferably, the auxiliary objective lens optical group G1 is composed of a first lens L1 and a second lens L2 cemented together; the front optical group G2 is composed of a third lens L3, a fourth lens L4, and a fifth lens L5, with the third lens L3 and the fourth lens L4 cemented together; the zoom optical group G3 is composed of a sixth lens L6 and a seventh lens L7; the compensation optical group G4 is composed of an eighth lens L8 and a ninth lens L9 cemented together; the rear optical group G5 is composed of a tenth lens L10 and an eleventh lens L11 cemented together; and the auxiliary tube lens optical group G6 is composed of a twelfth lens L12 and a thirteenth lens L13 cemented together.

[0011] Preferably, the second lens L2, the fourth lens L4, the eleventh lens L11, and the twelfth lens L12 are biconvex positive lenses, the fifth lens L5 is a plano-convex lens, the seventh lens L7 and the eighth lens L8 are biconcave negative lenses, the first lens L1, the third lens L3, the ninth lens L9, and the tenth lens L10 are meniscus lenses with negative optical power that are bent towards the image plane, and the sixth lens L6 and the thirteenth lens L13 are meniscus lenses with negative optical power that are bent towards the object plane.

[0012] The imaging field diameter of the above imaging system is φ16mm. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the optical system according to an embodiment of the present invention;

[0014] Figure 2 This is a light propagation diagram of the optical system of this invention at high magnification (6.6×).

[0015] Figure 3 This is a light propagation diagram of the optical system of this invention at low magnification (0.44×).

[0016] Figure 4 The MTF curve of the optical system in this embodiment of the invention reflects that the imaging quality of the optical system of the present invention meets the resolution requirements and has good imaging quality.

[0017] Figure 5 The diagram shows the spherical aberration curves of the optical system according to an embodiment of the present invention, reflecting that the aberrations of the optical system of the present invention have been well corrected. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0019] Example: Figure 1As shown, the present invention provides a large field-of-view, high-magnification digital monocular imaging system. From the object plane to the image plane along its optical axis, the system consists of a first lens L1, a second lens L2, a third lens L3, ..., up to a thirteenth lens L13. The first lens L1 and the second lens L2 are bonded together with photosensitive adhesive to form a first lens group G1, which we call the auxiliary objective lens optical group, with a combined focal length of 95mm. The third lens L3 to the fifth lens L5 form a second lens group G2, which we call the front optical group, with a combined focal length of 51.7mm. The third lens L3 and the fourth lens L4 are bonded together with photosensitive adhesive. The sixth lens L6 and the seventh lens L13... Lens L7 forms the third lens group G3, which we call the zoom lens group, with a combined focal length of -30.6mm; the eighth lens L8 and the ninth lens L9 are bonded together with photosensitive adhesive to form the fourth lens group G4, which we call the compensation lens group, with a combined focal length of -29.2mm; the tenth lens L10 and the eleventh lens L11 are bonded together with photosensitive adhesive to form the fifth lens group G5, which we call the rear lens group, with a combined focal length of 52.5mm; the twelfth lens L12 and the thirteenth lens L13 are bonded together with photosensitive adhesive to form the sixth lens group G6, which we call the auxiliary tube lens group, with a combined focal length of 172mm.

[0020] Among them, the second lens L2, the fourth lens L4, the eleventh lens L11 and the twelfth lens L12 are biconvex positive lenses, the fifth lens L5 is a plano-convex lens, the seventh lens L7 and the eighth lens L8 are biconcave negative lenses, the first lens L1, the third lens L3, the ninth lens L9 and the tenth lens L10 are meniscus lenses with negative optical power that are bent toward the image plane, and the sixth lens L6 and the thirteenth lens L13 are meniscus lenses with negative optical power that are bent toward the object plane.

[0021] The object light rays located at a working distance of 95mm become parallel rays after passing through the auxiliary objective lens optical group G1. In this embodiment, accessories such as coaxial incident illumination and polarizing devices can be selectively connected to increase the system's application range. Simultaneously, the auxiliary objective lens optical group G1 can be replaced with a metallurgical objective lens to achieve a higher optical magnification. The parallel rays after passing through the auxiliary objective lens optical group G1 then pass sequentially through the front optical group G2, zoom optical group G3, compensation optical group G4, and rear optical group G5, becoming parallel rays again. The front optical group G2 and the rear optical group G5 remain stationary, with a distance of 78mm between them. The parallel rays sent from the auxiliary objective lens optical group G1 to the front optical group G2 are not... Constrained by the optical system, the distance between the two lenses can be set within a range of 3–10 mm by the mechanical structure. The rear optical group G5 sends parallel light to the auxiliary telescope optical group G6, and the distance between them is also not constrained by the optical system, and can be set within a range of 2–15 mm by the mechanical structure. The zoom optical group G3 and the compensation optical group G4 move through a cam mechanism, thereby achieving continuous changes in the distance between the zoom optical group G3 and the front optical group G2, between the zoom optical group G3 and the compensation optical group G4, and between the compensation optical group G4 and the rear optical group G5, achieving a continuous zoom effect. Finally, the light is imaged by the auxiliary telescope optical group G6 onto the 170 mm image plane, which can be connected to a digital camera or CMOS chip to view the image on a display screen, realizing the transformation of human-machine vision and quantitative inspection.

[0022] All lenses in the above embodiments use glass from Chengdu Guangming Company, and all lenses employ multi-layer anti-reflection coatings with a reflectivity of less than 0.5%; system magnification range: 0.44×~6.6× continuously adjustable at any magnification; imaging field diameter: φ16mm.

[0023] The table below is a design data sheet for an example optical system of the present invention;

[0024] Table 1 Design data for the optical system

[0025]

[0026]

Claims

1. A large field-of-view, large zoom ratio digital monocular imaging system, comprising, along its optical axis from the object plane to the image plane, an auxiliary objective lens group G1, a front optical lens group G2, a zoom optical lens group G3, a compensation optical lens group G4, a rear optical lens group G5, and an auxiliary tube lens group G6, arranged sequentially. The front optical lens group G2 and the rear optical lens group G5 are fixed in position, while the zoom optical lens group G3 and the compensation optical lens group G4 are movable along the optical axis. Continuous magnification variation is achieved by changing the distances between the zoom optical lens group G3 and the front optical lens group G2, between the zoom optical lens group G3 and the compensation optical lens group G4, and between the compensation optical lens group G4 and the rear optical lens group G5. The system's magnification is characterized by... The auxiliary objective lens group G1 has a focal length of 95mm, the front optical group G2 has a focal length of 51.7mm, the zoom optical group G3 has a focal length of -30.6mm, the compensation optical group G4 has a focal length of -29.2mm, the rear optical group G5 has a focal length of 52.5mm, and the auxiliary tube lens group G6 has a focal length of 172mm. The auxiliary objective lens group G1 sends parallel light rays to the front optical group G2; the rear optical group G5 sends parallel light rays to the auxiliary tube lens group G6. The distance between the front optical group G2 and the rear optical group G5 is 78mm, and the system magnification range is 0.44× to 6.6×.

2. The large field-of-view, high magnification digital monocular imaging system as described in claim 1, characterized in that... The auxiliary objective lens group G1 is a metallurgical optical objective lens group.

3. The large field-of-view, high magnification digital monocular imaging system as described in claim 1, characterized in that... The zoom lens group G3 and the compensation lens group G4 are moved along the optical axis through a cam mechanism.

4. The large field-of-view, large magnification digital monocular imaging system as described in claim 1, characterized in that... The auxiliary objective lens optical group G1 has an object plane at its front focal point, and the auxiliary tube lens optical group G6 has a digital camera or CMOS chip at its rear focal point.

5. A large field-of-view, high magnification digital monocular imaging system as described in claim 1, characterized in that... The auxiliary objective lens group G1 consists of a first lens L1 and a second lens L2 cemented together. The front optical group G2 consists of a third lens L3, a fourth lens L4, and a fifth lens L5, with the third lens L3 and the fourth lens L4 cemented together. The zoom optical group G3 consists of a sixth lens L6 and a seventh lens L7. The compensation optical group G4 consists of an eighth lens L8 and a ninth lens L9 cemented together. The rear optical group G5 consists of a tenth lens L10 and an eleventh lens L11 cemented together. The auxiliary tube lens optical group G6 consists of a twelfth lens L12 and a thirteenth lens L13 cemented together.

6. The large field-of-view, large magnification digital monocular imaging system as described in claim 5, characterized in that... The second lens L2, the fourth lens L4, the eleventh lens L11, and the twelfth lens L12 are biconvex positive lenses; the fifth lens L5 is a plano-convex lens; the seventh lens L7 and the eighth lens L8 are biconcave negative lenses; the first lens L1, the third lens L3, the ninth lens L9, and the tenth lens L10 are meniscus lenses with negative optical power that are bent towards the image plane; and the sixth lens L6 and the thirteenth lens L13 are meniscus lenses with negative optical power that are bent towards the object plane.

7. A large field-of-view, high magnification digital monocular imaging system as described in any one of claims 1 to 6, characterized in that... The imaging field diameter of the imaging system is φ16mm.

Images