TWI339276B - Lens system - Google Patents

Description

1339276 - May 25, 2005, Nuclear Replacement Page VI. Description of the Invention: [Technical Field of the Invention] [0001] The present invention relates to a lens system, and more particularly to a lens system for an electronic device. [Prior Art]

[0002] In recent years, with the development of multimedia, there is a demand for an imaging element of a solid-state imaging device such as a CCD (Charged Coupled Device) or a CMOS (Comp1ementary Metal Oxide Semi Conduct-or) used for a notebook computer, a videophone, or a mobile phone. getting bigger. This increase in demand itself requires further miniaturization of the lens system. [0003] On the other hand, due to the improvement of the process technology of such a solid into a yf-like device such as CCDS^CMOS, an imaging device having only a few micro-micrometers in size has been fabricated, making the system compact while being miniaturized. Increased the resolution of the camera lens. Therefore, a lens system having a small length, excellent optical performance, and good image quality is a development side of today's miniature image pickup elements. ······ ' · - Direction. The small length means that the distance from the first side of the lens system to the imaging surface (i.e., the total length of the imaging system) is short. SUMMARY OF THE INVENTION [0004] In view of the above, it is necessary to provide a lens system that is miniaturized and has excellent imaging performance. [0005] A lens system comprising, in order from the object side to the imaging surface, a first lens having a negative power, a second lens having a positive power, and a third lens having a negative power. A fourth lens having positive power, a fifth lens having negative power, and a sixth lens having positive power. The lens system satisfies the following conditions: TT/fSl. 68 and 096134490 Form No. A0101 Page 3/Total 19 Page 0993181223-0 1339276 I. 25th of the month of 099 隹正菩^] 0.3<f/f23<〇. 4, wherein Ή is the distance from the surface of the first lens close to the object side to the imaging surface of the system, f23 is the effective focal length of the lens combination composed of the second lens and the third lens, and f is the effective focal length of the lens system 〇 The conditional TTVfS1. 68 limits the total length of the lens system. Conditional

0. 3<f/i23<〇. 4 guarantees a balance between the total length of the lens system and the spherical aberration and coma. The lens system 'which satisfies the above conditions has a small length to satisfy the requirement of miniaturization of the lens system' and the lens system assures a final image quality with a reduced length. [Embodiment] [0007] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. [〇〇〇8] Please refer to FIG. 1 , which is a present invention: a painful cage game system 100. The lens system 1 includes, in order from the object side to the imaging surface, a first lens 10 having a negative power, a second lens 20 having a positive power, and a third lens 30 having a negative power. A fourth lens 4'' having a positive power, a fifth lens 5' having a negative power, and a sixth lens 60 having a positive power. [0009] When the lens system 1 〇 0 is used for imaging, 'light from the subject is incident on the lens system 100 from the object side direction and sequentially passes through the first lens 10, the second lens 20, and the third lens 30. The fourth lens 40, the fifth lens 50, and the sixth lens 6 are finally concentrated on an imaging surface 90, and the image sensing device such as CCD or CMOS is disposed at the imaging surface 90. The image of the subject. [0010] In order to achieve miniaturization and high imaging performance requirements, the lens system 1 〇〇 meets 0993181223-0 096134490 Form No. A0101 No. 4 1 / Total 19 pages 099 May 25 Nuclear replacement page The following conditional formula: [0011] (1) TT / f S1. 68 and [0012] (2) 0. 3 < f " 23 < 0. 4. Wherein TT is the distance from the surface of the first lens close to the object side to the system imaging surface 90, f23 is the effective focal length of the lens combination of the second lens 20 and the third lens 30, and f is a lens The effective focal length of system 100. Condition (1) limits the total length of the lens system 100. Conditional formula (2) guarantees a balance between the total length of the lens system 100 and the spherical aberration and coma. [0014] Preferably, the sixth lens 60 further satisfies the following condition: I · t ' [0015] (3) l < f / f6 < l. 。 '·· [0016] where f6 is the focal length of the sixth lens. Condition (3) satisfies the lens system 100's requirement for total power, while making the lens system 100 closer to the telecentric imaging system, enhancing the light-receiving rate of the external light sensor, ensuring the total length and image of the lens system 100. The balance between the differences. [0017] In order to better eliminate the chromatic aberration of the lens system 100, especially the chromatic aberration of magnification, the second lens 20, the third lens 30, and the fourth lens 40 also satisfy the following conditions: [0018] (4) Vd2 > Vd3 and [0019] (5) Vd4>Vd5. [0020] wherein Vd2 is the Abbe number of the second lens 20, Vd3 is the Abbe number of the third lens 30, Vd4 is the Abbe number of the fourth lens 40, and Vd5 is the Abbe number of the fifth lens. Conditional formulas (4) and (5) help to reduce the volume of the lens system 100 and ensure a balance between the total length of the lens system 100 and the chromatic aberration. Form No. A0101 Page 5 of 19 0993181223-0 1339276 I nciQiSE nq Day Pass

I — — — · 墨一/*<J — — W « I · A V, P, I

[0021] To ensure that the aperture or the shutter is placed between the first lens 10 and the second lens 20, the first lens 10 and the second lens 20 are also guaranteed to satisfy the following conditions: [0022] (6) 0. 2 < DA1- 2/f<0. 3. [0023] wherein DA1-2 is an axial interval between the first lens 10 and the second lens 20 (the length of the optical axis between the image side surface of the first lens 10 and the side surface of the second lens 20).

[0024] The lens system 100 further includes an aperture stop 70 and a filter 80. The aperture 70 is located between the first lens 10 and the second lens 20 to limit the light flux that passes through the first lens 10 into the second lens 20, and passes through the first transparent clock: !!# Light: Turn. Can be more symmetrical, so that the coma of the lens system 100 can be repaired. The section of the lens system 100: shorten the length of the lens system 100, can be used to imperfect cloth purple;: 3⁄4 mirror 20 side surface The outer ring acts as a stop 70. It will be appreciated that the arrangement of the aperture 70 is also advantageous for shortening the overall length of the lens system. The filter 80 is located between the sixth lens 60 and the imaging surface 90 and is mainly used to filter out light rays entering the infrared light of the lens system 100. [0025] It can be understood that the first lens 10, the second lens 20, the third lens 30, the fourth lens 40, the fifth lens 50, and the sixth lens 60 of the lens system 100 of the embodiment of the present invention are all made of glass. While ensuring good image quality, the cost is relatively low, and mass production is easy. 2 to 7, the lens system 100 will be described in detail with reference to specific embodiments. [0027] In each of the following embodiments, each of the first lens 10, the second lens 20, the third lens 30, the fourth lens 40, the fifth lens 50, and the sixth lens 60 is 096134490. Form No. A0101, page 6 / Total 19 pages 0993181223-0 1339276 i 1 May 25, 099 ^ The replacement surface is spherical. [0028] f: effective focal length of the lens system 1; FN〇: F (aperture) number; 2ω: angle of view. [0030] Embodiment 1 [0030] The optical elements of the lens system 100 satisfy the conditions of Table 1, and ΤΤ = 11.64 mm (mm); f = 6, 91 mm; f23 = 1 9. 2939 mm; FNo = 3 19 ; 2ω = 56. . Xin [0031] Table 1 [0032] Lens system 100 radius of curvature (mm) ----- thickness (mm):,):; refractive index • .> - Abbe number object infinity 1000 .--- —- A first lens 10 0 side surface 55.82214 〇. 52 • -------- 1.58913 61.135 The first lens 10 depends on the side surface 27.47293 1.3 ----- — 阑 70 infinity 0.22 1 — — The second lens 20 is on the side surface 3.571711 —— 〇·976173 5 882997 • v 40.7651 The second lens 2 0 is on the image side surface 10.97649 〇. 1 —--—— One by one — Form No. Α0101 笫7 pages/total 19 pages 0993181223-0 096134490 1339276 |〇S9年05月2S 日广正Replaces the third lens 30 by the side surface -5.59937 0. 52 1.698947 30.1 279 The third lens 30 depends on the side surface 3.373019 0.552519 The lens 40 side surface 1 0. 1 5544 -, 1.23667 1.788001 47.3685 The fourth lens 40 image side surface 3.815141 0.707247 :.y^- r 'V1·. ; .3⁄43⁄4.... ~ Fifth lens 5 0 object side surface 2.661624 0752 1?? 92701 35.3101 Fifth lens 50 image side surface 8.585195 0.997556 6 Sixth lens 6 0 object side surface 9. 9103 1.880943 1.816 46 62 Sixth lens 60 image side surface -11.4479 0,413466 6 Filter 80 Object side table infinity 0. 8 1.5168 64. 16 Form number A0] 01 Page 8 / Total 19 page 0993181223-0

096134490 1339276 • -r 099 D5 25th revision replacement page *----- Filter 8 0 Image side surface Infinity —------ 0.9 ~~—

In the lens system 100 of the first embodiment, the spherical aberration, curvature of field, and distortion are as shown in Figs. 2 to 4, respectively. In Fig. 2, spherical aberration values are observed for the g line (wavelength value of 435 8 nanometers (nm)), the d line (wavelength value of 587.6 nm), and the zero line (wavelength value of 656.3 nm), respectively. In general, the lens system 100 of embodiment j produces a spherical aberration value in the range of (-〇·1 mm, 0.1 mm) for visible light (wavelength range between 4 〇〇 nm _7 〇〇 (10)). In Fig. 3, S (meridian curvature value) and T (radial field curvature value) are controlled within the range of :, * (_0. lmm, 0.1 mm). In Fig. 4, the current peak rate is controlled within (_2%, 2%). It can be seen that the spherical aberration, curvature of field and distortion of the system can be well corrected. [0033] Embodiment 2 [0034] The optical elements of the lens system 1 〇 0 satisfy the conditions of Table 2, and f = 7. 098 mm > f23 = 18. 81 25 mm i FNo = 3. 19 , 2ω = 53 38 [0035] Table 2 Lens System 100 Curvature Radius (mm) Thickness (mm) ^----^ Refractive index Abbe number object infinity 1000 P ~ - First lens 10 relying side 138 0.515 - 1.48749 70.4058 Form No. A0101 Page 9 / 19 pages 0993181223-0 096134490 1339276 I 099 May 2 S Guangzheng surface I First lens 10 image side surface 38.5071 1.2933 Optical aperture 70 Infinity 0.2166 — --- Second lens 20 Object side surface 3.434642 0.995493 3 1.90217 40.7651 Second lens 20 image side surface 12.82318 0.1 ν''; 妒η: third lens 30 object side surface 6. 115171 0.Γ515 • ... · ····: More, [:51. 72^672 28.6914 Third lens 30 image side surface 3.257676 0.553578 Fourth lens 40 object side surface 8. 529067 1.220021 1.743972 44.8504 Fourth lens 40 image side surface -3.63408 0.681474 Fifth lens 50 The side surface of the object 2.509925 0.515 1.642602 34.2214 Form No. A0101 Page 0 of 19 Page 0993181223-0

096134490 1339276 • s May 25, 2017, the fifth positive lens 5 0 image side surface 1 0.56706 0.90 1 031 sixth lens 60 object side surface 10.2255 1.944665 1.8068 45.6199 sixth lens 60 image side surface 10.11677 0.464267 -- --- Filter 80 on the side of the object side infinity 0.8 ·. · .. \· ..- 1.5168 1 , ' .V ........ ;...V, Ή.' 64. 16 Filter 80 Image side surface infinity 0.9 〜---^ The lens system 100 of the second embodiment has spherical aberration, distortion and distortion as shown in Figs. 5 to 7, respectively. In Fig. 5, spherical aberration values were observed for the g-line (wavelength value 435.8 nm) 'd line (wavelength value 5_8 + 7.'6 nm) and c-line (wavelength value 656.3 nm). In general, the lens system 100 of Example 2 produces spherical aberration values in the range of (-0.1 mm, 0.1 mm) for visible light (wavelengths ranging from 4 〇〇 nm to 7 〇〇 nm). In Fig. 6, S (meridian field curvature value) and T (radial field curvature value) are both controlled within the range of (_〇 imm, 〇 imm). The distortion rate in Fig. 7 is controlled within the range of (_2%, 2%). Thus, the spherical aberration, curvature of field, and distortion of the lens system 100 can be well corrected. The lens system 100 has a small length to satisfy a small lens system

096134490 Form No. A0101 Page 11 of 19 0993181223-0 1339276

I. May 3, 099 □ The child is replacing the requirements of r I, and the lens system guarantees the balance between the total length of the lens system and the aberration when the length is reduced, and improves the quality of the final image obtained. [0038] In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art of the present invention should be included in the following claims.

[Simple description of the map]

I

1 is a schematic diagram of a lens system according to an embodiment of the present invention.卞:: > t. Micro-wiping. [0040] FIG. 2 is a view of the first embodiment of the present invention. FIG. 4 is a distortion diagram of a lens system according to Embodiment 1 of the present invention. 5 is a spherical aberration diagram of a lens system according to Embodiment 2 of the present invention. 6 is a field curvature diagram of a lens system according to Embodiment 2 of the present invention. 7 is a distortion diagram of a lens system according to Embodiment 2 of the present invention. [Main Element Symbol Description] [0046] Lens System 100 [0047] First Lens 10 [0048] Second Lens 20 [0049] Third Lens 30 [0050] Fourth Lens 40 096134490 Form No. 101 0101 Page 12 of 19 Page 0993181223-0 1339276 • tt May 25th, 2005 after the replacement page [0051] Fifth lens 50 [0052] Sixth lens 60 [0053] Optical aperture 70 [0054] Light-passing sheet 80 [0055] Imaging surface 90 096丨34490 Form No. A0101 Page 13 / Total 19 Page 0993181223-0

Claims (1)

1339276 I 099 S5 Month □珍IE笞 VII. Patent application scope: What is claimed is: 1. A lens system comprising, in order from an object side to an imaging surface, a first lens having a negative power, a second lens having a positive power, and a third lens having a negative power, one having a fourth lens having a positive power, a fifth lens having a negative power, and a sixth lens having a positive power, the lens system satisfying the following conditions: 1. 64STT/f S1. 68 and 0.3. &quot;f23&lt;0. 4, wherein TT is the distance from the surface of the first lens near the object side to the imaging surface of the system, and f 23 is the effective focal length of the lens combination of the second lens and the third lens, ί is the effective focal length of the lens system 〇2. As described in the fourth lens of the first paragraph of the patent application, the sixth. I; y • μ * · * ·, must · ' lens also meets the following conditions :l&lt;f/1:^3⁄4, where is the focal length of the sixth lens. 3. The lens system according to claim 1, wherein the lens system further satisfies the following conditional formula: Vd2 &gt; Vd3 and Vd4 &gt; Vd5, wherein Vd2 is the Abbe number of the second lens, and Vd3 is the The Abbe number of the three lenses, Vd4 is the Abbe number of the fourth lens, and Vd5 is the Abbe number of the fifth lens. 4. The lens system of claim 1, wherein the lens system further satisfies the following relationship: 0. 2 &lt; DA1-2M <0.3, wherein DA1-2 is the first lens and the first The two lenses are spaced on the axis. 5. The lens system of claim 1, wherein the lens system further comprises an aperture between the first lens and the second lens. 6 as claimed in claim 5 The lens system, wherein the aperture is an opaque material coated on an outer circumference of the second lens object side surface. 096134490 Form No. A0101 Page 14 of 19 0993181223-0 13,39276 ___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Each surface of a lens, a second lens, a third lens, a fourth lens 'fifth lens, and a sixth lens is a spherical surface. 8. The lens system of claim 1, wherein the first 'the second lens, the second lens, the third lens, the fourth lens, the fifth lens, and the sixth lens are all made of glass. 9. The lens system of claim 1, wherein the lens system further comprises an infrared filter disposed on the image side of the sixth lens. 096134490 Form No. A0101 Page 15 of 19 0993181223-0